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Castelnovo A, Casetta C, Cavallotti S, Marcatili M, Del Fabro L, Canevini MP, Sarasso S, D'Agostino A. Proof-of-concept evidence for high-density EEG investigation of sleep slow wave traveling in First-Episode Psychosis. Sci Rep 2024; 14:6826. [PMID: 38514761 PMCID: PMC10958040 DOI: 10.1038/s41598-024-57476-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 03/18/2024] [Indexed: 03/23/2024] Open
Abstract
Schizophrenia is thought to reflect aberrant connectivity within cortico-cortical and reentrant thalamo-cortical loops, which physiologically integrate and coordinate the function of multiple cortical and subcortical structures. Despite extensive research, reliable biomarkers of such "dys-connectivity" remain to be identified at the onset of psychosis, and before exposure to antipsychotic drugs. Because slow waves travel across the brain during sleep, they represent an ideal paradigm to study pathological conditions affecting brain connectivity. Here, we provide proof-of-concept evidence for a novel approach to investigate slow wave traveling properties in First-Episode Psychosis (FEP) with high-density electroencephalography (EEG). Whole-night sleep recordings of 5 drug-naïve FEP and 5 age- and gender-matched healthy control subjects were obtained with a 256-channel EEG system. One patient was re-recorded after 6 months and 3 years of continuous clozapine treatment. Slow wave detection and traveling properties were obtained with an open-source toolbox. Slow wave density and slow wave traveled distance (measured as the line of longest displacement) were significantly lower in patients (p < 0.05). In the patient who was tested longitudinally during effective clozapine treatment, slow wave density normalized, while traveling distance only partially recovered. These preliminary findings suggest that slow wave traveling could be employed in larger samples to detect cortical "dys-connectivity" at psychosis onset.
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Affiliation(s)
- Anna Castelnovo
- Sleep Medicine Unit, Neurocenter of Italian Switzerland, Ente Ospedaliero Cantonale (EOC), Via Tesserete 46, 6900, Lugano, Switzerland.
- Faculty of Biomedical Sciences, University of Italian Switzerland, Lugano, Switzerland.
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.
| | - Cecilia Casetta
- Department of Mental Health and Addiction, ASST Santi Paolo e Carlo, Via A. Di Rudinì 8, 20142, Milan, Italy
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Simone Cavallotti
- Department of Mental Health and Addiction, ASST Santi Paolo e Carlo, Via A. Di Rudinì 8, 20142, Milan, Italy
| | - Matteo Marcatili
- Psychiatric Department, ASST Monza, San Gerardo Hospital, Monza, Italy
| | - Lorenzo Del Fabro
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy
- Department of Neurosciences and Mental Health, IRCCS Fondazione Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy
| | - Maria Paola Canevini
- Department of Mental Health and Addiction, ASST Santi Paolo e Carlo, Via A. Di Rudinì 8, 20142, Milan, Italy
- Department of Health Sciences, Università degli Studi di Milano, Milan, Italy
| | - Simone Sarasso
- Department of Biomedical and Clinical Sciences "L. Sacco", Università degli Studi di Milano, Via G.B. Grassi 74, 20157, Milan, Italy.
| | - Armando D'Agostino
- Department of Mental Health and Addiction, ASST Santi Paolo e Carlo, Via A. Di Rudinì 8, 20142, Milan, Italy.
- Department of Health Sciences, Università degli Studi di Milano, Milan, Italy.
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Kaar SJ, Nottage JF, Angelescu I, Marques TR, Howes OD. Gamma Oscillations and Potassium Channel Modulation in Schizophrenia: Targeting GABAergic Dysfunction. Clin EEG Neurosci 2024; 55:203-213. [PMID: 36591873 PMCID: PMC10851642 DOI: 10.1177/15500594221148643] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 12/08/2022] [Accepted: 12/12/2022] [Indexed: 01/03/2023]
Abstract
Impairments in gamma-aminobutyric acid (GABAergic) interneuron function lead to gamma power abnormalities and are thought to underlie symptoms in people with schizophrenia. Voltage-gated potassium 3.1 (Kv3.1) and 3.2 (Kv3.2) channels on GABAergic interneurons are critical to the generation of gamma oscillations suggesting that targeting Kv3.1/3.2 could augment GABAergic function and modulate gamma oscillation generation. Here, we studied the effect of a novel potassium Kv3.1/3.2 channel modulator, AUT00206, on resting state frontal gamma power in people with schizophrenia. We found a significant positive correlation between frontal resting gamma (35-45 Hz) power (n = 22, r = 0.613, P < .002) and positive and negative syndrome scale (PANSS) positive symptom severity. We also found a significant reduction in frontal gamma power (t13 = 3.635, P = .003) from baseline in patients who received AUT00206. This provides initial evidence that the Kv3.1/3.2 potassium channel modulator, AUT00206, may address gamma oscillation abnormalities in schizophrenia.
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Affiliation(s)
- Stephen J. Kaar
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- MRC London Institute of Medical Sciences, Hammersmith Hospital, London, UK
- Division of Psychology and Mental Health, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
| | - Judith F. Nottage
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Ilinca Angelescu
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- Max Planck UCL Centre for Computational Psychiatry and Ageing Research London, London, UK
| | - Tiago Reis Marques
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- MRC London Institute of Medical Sciences, Hammersmith Hospital, London, UK
| | - Oliver D. Howes
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- MRC London Institute of Medical Sciences, Hammersmith Hospital, London, UK
- Faculty of Medicine, Institute of Clinical Sciences (ICS), Imperial College London, London, UK
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3
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Eo J, Kang J, Youn T, Park HJ. Neuropharmacological computational analysis of longitudinal electroencephalograms in clozapine-treated patients with schizophrenia using hierarchical dynamic causal modeling. Neuroimage 2023; 275:120161. [PMID: 37172662 DOI: 10.1016/j.neuroimage.2023.120161] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 04/15/2023] [Accepted: 05/09/2023] [Indexed: 05/15/2023] Open
Abstract
The hierarchical characteristics of the brain are prominent in the pharmacological treatment of psychiatric diseases, primarily targeting cellular receptors that extend upward to intrinsic connectivity within a region, interregional connectivity, and, consequently, clinical observations such as an electroencephalogram (EEG). To understand the long-term effects of neuropharmacological intervention on neurobiological properties at different hierarchical levels, we explored long-term changes in neurobiological parameters of an N-methyl-D-aspartate canonical microcircuit model (CMM-NMDA) in the default mode network (DMN) and auditory hallucination network (AHN) using dynamic causal modeling of longitudinal EEG in clozapine-treated patients with schizophrenia. The neurobiological properties of the CMM-NMDA model associated with symptom improvement in schizophrenia were found across hierarchical levels, from a reduced membrane capacity of the deep pyramidal cell and intrinsic connectivity with the inhibitory population in DMN and intrinsic and extrinsic connectivity in AHN. The medication duration mainly affects the intrinsic connectivity and NMDA time constant in DMN. Virtual perturbation analysis specified the contribution of each parameter to the cross-spectral density (CSD) of the EEG, particularly intrinsic connectivity and membrane capacitances for CSD frequency shifts and progression. It further reveals that excitatory and inhibitory connectivity complements frequency-specific CSD changes, notably the alpha frequency band in DMN. Positive and negative synergistic interactions exist between neurobiological properties primarily within the same region in patients treated with clozapine. The current study shows how computational neuropharmacology helps explore the multiscale link between neurobiological properties and clinical observations and understand the long-term mechanism of neuropharmacological intervention reflected in clinical EEG.
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Affiliation(s)
- Jinseok Eo
- Graduate School of Medical Science, Brain Korea 21 Project, Department of Nuclear Medicine, Department of Psychiatry, Yonsei University College of Medicine, Seoul, Republic of Korea; Center for Systems and Translational Brain Science, Institute of Human Complexity and Systems Science, Yonsei University, Seoul, Republic of Korea
| | - Jiyoung Kang
- Department of Scientific Computing, Pukyong National University, Busan, Republic of Korea; Center for Systems and Translational Brain Science, Institute of Human Complexity and Systems Science, Yonsei University, Seoul, Republic of Korea
| | - Tak Youn
- Department of Psychiatry and Electroconvulsive Therapy Center, Dongguk University International Hospital, Goyang, Republic of Korea; Institute of Buddhism and Medicine, Dongguk University, Seoul, Republic of Korea
| | - Hae-Jeong Park
- Graduate School of Medical Science, Brain Korea 21 Project, Department of Nuclear Medicine, Department of Psychiatry, Yonsei University College of Medicine, Seoul, Republic of Korea; Center for Systems and Translational Brain Science, Institute of Human Complexity and Systems Science, Yonsei University, Seoul, Republic of Korea; Department of Cognitive Science, Yonsei University, Seoul, Republic of Korea.
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4
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Ozaki T, Mikami K, Toyomaki A, Hashimoto N, Ito YM, Kusumi I. Assessment of electroencephalography modification by antipsychotic drugs in patients with schizophrenia spectrum disorders using frontier orbital theory: A preliminary study. Neuropsychopharmacol Rep 2023. [PMID: 36811149 DOI: 10.1002/npr2.12318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 12/21/2022] [Accepted: 12/26/2022] [Indexed: 02/24/2023] Open
Abstract
AIM Schizophrenia is characterized by an abnormality in electroencephalography (EEG), which can be affected by antipsychotic drugs. Recently, the mechanism underlying these EEG alterations in schizophrenia patients was reframed from the perspective of redox abnormalities. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) can be calculated using a computational method and may be useful for evaluating the antioxidant/prooxidant effect of antipsychotic drugs. Thus, we examined the association between the effects of antipsychotic monotherapy on quantitative EEG and HOMO/LUMO energy. METHODS We used medical report data including EEG results of psychiatric patients admitted to Hokkaido University Hospital. We extracted the EEG records of patients diagnosed with a schizophrenia spectrum disorder undergoing antipsychotic monotherapy during the natural course of treatment (n = 37). We evaluated the HOMO/LUMO energy of all antipsychotic drugs using computational methods. Multiple regression analyses were used to examine the relationship between the HOMO/LUMO energy of all antipsychotic drugs and spectral band power in all patients. Statistical significance was set at p < 6.25 × 10-4 adjusted with Bonferroni correction. RESULTS We showed that the HOMO energy of all antipsychotic drugs had weak positive correlations with delta- and gamma-band power (e.g., standardized β = 0.617 for delta in the F3 channel, p = 6.6 × 10-5 ; standardized β = 0.563 for gamma in the O1 channel, p = 5.0 × 10-4 ). CONCLUSION Although there may be unexpected bias and confounding factors, our findings suggest that the effect of antipsychotic drugs on EEG may be related to their antioxidant actions.
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Affiliation(s)
- Takashi Ozaki
- Department of Psychiatry, Graduate School of Medicine, Hokkaido University, Sapporo, Japan.,Department of psychiatry, Koyogaoka Hospital, Abashiri, Japan
| | - Koichiro Mikami
- Department of material chemistry, Sagami Chemical Research Institute, Ayase, Japan
| | - Atsuhito Toyomaki
- Department of Psychiatry, Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Naoki Hashimoto
- Department of Psychiatry, Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Yoichi M Ito
- Data Science Center, Promotion Unit, Institute of Health Science Innovation for Medical Care, Hokkaido University Hospital, Sapporo, Japan
| | - Ichiro Kusumi
- Department of Psychiatry, Graduate School of Medicine, Hokkaido University, Sapporo, Japan
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5
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E DO, V MS, S LV, E SY. Fractal Structure of Brain Electrical Activity of Patients With Mental Disorders. Front Physiol 2022; 13:905318. [PMID: 35923231 PMCID: PMC9340582 DOI: 10.3389/fphys.2022.905318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 06/23/2022] [Indexed: 11/19/2022] Open
Abstract
This work was aimed at a comparative analysis of the degree of multifractality of electroencephalographic time series obtained from a group of healthy subjects and from patients with mental disorders. We analyzed long-term records of patients with paranoid schizophrenia and patients with depression. To evaluate the properties of multifractal scaling of various electroencephalographic time series, the method of maximum modulus of the wavelet transform and multifractal analysis of fluctuations without a trend were used. The stability of the width and position of the singularity spectrum for each of the test groups was revealed, and a relationship was established between the correlation and anticorrelation dynamics of successive values of the electroencephalographic time series and the type of mental disorders. It was shown that the main differences between the multifractal properties of brain activity in normal and pathological conditions lie in the different width of the multifractality spectrum and its location associated with the correlated or anticorrelated dynamics of the values of successive time series. It was found that the schizophrenia group is characterized by a greater degree of multifractality compared to the depression group. Thus, the degree of multifractality can be included in a set of tests for differential diagnosis and research of mental disorders.
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Affiliation(s)
- Dick O. E
- Laboratory of Physiology of Reception, Pavlov Institute of Physiology of Russian Academy of Science, St. Petersburg, Russia
- *Correspondence: Dick O. E,
| | - Murav’eva S. V
- Laboratory of Vision Physiology, Pavlov Institute of Physiology of Russian Academy of Science, St. Petersburg, Russia
| | - Lebedev V. S
- Laboratory of Vision Physiology, Pavlov Institute of Physiology of Russian Academy of Science, St. Petersburg, Russia
| | - Shelepin Yu. E
- Laboratory of Vision Physiology, Pavlov Institute of Physiology of Russian Academy of Science, St. Petersburg, Russia
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6
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Raymond N, Lizano P, Kelly S, Hegde R, Keedy S, Pearlson GD, Gershon ES, Clementz BA, Tamminga CA, Keshavan M. What can clozapine’s effect on neural oscillations tell us about its therapeutic effects? A scoping review and synthesis. Biomark Neuropsychiatry 2022. [DOI: 10.1016/j.bionps.2022.100048] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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7
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Adlan LG, Csordás-Nagy M, Bodosi B, Kalmár G, Nyúl LG, Nagy A, Kekesi G, Büki A, Horvath G. Sleep-Wake Rhythm and Oscillatory Pattern Analysis in a Multiple Hit Schizophrenia Rat Model (Wisket). Front Behav Neurosci 2022; 15:799271. [PMID: 35153694 PMCID: PMC8831724 DOI: 10.3389/fnbeh.2021.799271] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 12/30/2021] [Indexed: 11/13/2022] Open
Abstract
Electroencephalography studies in schizophrenia reported impairments in circadian rhythm and oscillatory activity, which may reflect the deficits in cognitive and sensory processing. The current study evaluated the circadian rhythm and the state-dependent oscillatory pattern in control Wistar and a multiple hit schizophrenia rat model (Wisket) using custom-made software for identification of the artifacts and the classification of sleep-wake stages and the active and quiet awake substages. The Wisket animals have a clear light-dark cycle similar to controls, and their sleep-wake rhythm showed only a tendency to spend more time in non-rapid eye movement (NREM) and less in rapid eye movement (REM) stages. In spite of the weak diurnal variation in oscillation in both groups, the Wisket rats had higher power in the low-frequency delta, alpha, and beta bands and lower power in the high-frequency theta and gamma bands in most stages. Furthermore, the significant differences between the two groups were pronounced in the active waking substage. These data suggest that the special changes in the oscillatory pattern of this schizophrenia rat model may have a significant role in the impaired cognitive functions observed in previous studies.
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Affiliation(s)
- Leatitia Gabriella Adlan
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Mátyás Csordás-Nagy
- Department of Technical Informatics, Faculty of Science and Informatics, Institute of Informatics, University of Szeged, Szeged, Hungary
| | - Balázs Bodosi
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - György Kalmár
- Department of Technical Informatics, Faculty of Science and Informatics, Institute of Informatics, University of Szeged, Szeged, Hungary
| | - László G. Nyúl
- Department of Image Processing and Computer Graphics, Faculty of Science and Informatics, Institute of Informatics, University of Szeged, Szeged, Hungary
| | - Attila Nagy
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Gabriella Kekesi
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Alexandra Büki
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Gyongyi Horvath
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
- *Correspondence: Gyongyi Horvath,
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8
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Bowman C, Richter U, Jones CR, Agerskov C, Herrik KF. Activity-State Dependent Reversal of Ketamine-Induced Resting State EEG Effects by Clozapine and Naltrexone in the Freely Moving Rat. Front Psychiatry 2022; 13:737295. [PMID: 35153870 PMCID: PMC8830299 DOI: 10.3389/fpsyt.2022.737295] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 01/06/2022] [Indexed: 11/13/2022] Open
Abstract
Ketamine is a non-competitive N-Methyl-D-aspartate receptor (NMDAR) antagonist used in the clinic to initiate and maintain anaesthesia; it induces dissociative states and has emerged as a breakthrough therapy for major depressive disorder. Using local field potential recordings in freely moving rats, we studied resting state EEG profiles induced by co-administering ketamine with either: clozapine, a highly efficacious antipsychotic; or naltrexone, an opioid receptor antagonist reported to block the acute antidepressant effects of ketamine. As human electroencephalography (EEG) is predominantly recorded in a passive state, head-mounted accelerometers were used with rats to determine active and passive states at a high temporal resolution to offer the highest translatability. In general, pharmacological effects for the three drugs were more pronounced in (or restricted to) the passive state. Specifically, during inactive periods clozapine induced increases in delta (0.1-4 Hz), gamma (30-60 Hz) and higher frequencies (>100 Hz). Importantly, it reversed the ketamine-induced reduction in low beta power (10-20 Hz) and potentiated ketamine-induced increases in gamma and high frequency oscillations (130-160 Hz). Naltrexone inhibited frequencies above 50 Hz and significantly reduced the ketamine-induced increase in high frequency oscillations. However, some frequency band changes, such as clozapine-induced decreases in delta power, were only seen in locomoting rats. These results emphasise the potential in differentiating between activity states to capture drug effects and translate to human resting state EEG. Furthermore, the differential reversal of ketamine-induced EEG effects by clozapine and naltrexone may have implications for the understanding of psychotomimetic as well as rapid antidepressant effects of ketamine.
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Affiliation(s)
- Christien Bowman
- Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands.,Bio Imaging Laboratory, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Ulrike Richter
- Department of Circuit Biology, Lundbeck, Copenhagen, Denmark
| | - Christopher R Jones
- Department of Pharmacokinetic and Pharmacodynamic Modeling and Simulation, Lundbeck, Copenhagen, Denmark
| | - Claus Agerskov
- Department of Circuit Biology, Lundbeck, Copenhagen, Denmark
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Ozaki T, Toyomaki A, Hashimoto N, Kusumi I. Quantitative Resting State Electroencephalography in Patients with Schizophrenia Spectrum Disorders Treated with Strict Monotherapy Using Atypical Antipsychotics. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE : THE OFFICIAL SCIENTIFIC JOURNAL OF THE KOREAN COLLEGE OF NEUROPSYCHOPHARMACOLOGY 2021; 19:313-322. [PMID: 33888660 PMCID: PMC8077067 DOI: 10.9758/cpn.2021.19.2.313] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/12/2020] [Accepted: 08/13/2020] [Indexed: 12/16/2022]
Abstract
OBJECTIVE The effect of antipsychotic drugs on quantitative electroencephalography (EEG) has been mainly examined by the administration of a single test dose or among patients using combinations of other psychotropic drugs. We therefore investigated the effects of strict monotherapy with antipsychotic drugs on quantitative EEG among schizophrenia patients. METHODS Data from 2,364 medical reports with EEG results from psychiatric patients admitted to the Hokkaido University Hospital were used. We extracted EEG records of patients who were diagnosed with schizophrenia spectrum disorders and who were either undergoing strict antipsychotic monotherapy or were completely free of psychotropic drugs. The spectral power was compared between drug-free patients and patients using antipsychotic drugs. We also performed multiple regression analysis to evaluate the relationship between spectral power and the chlorpromazine equivalent daily dose of antipsychotics in all the patients. RESULTS We included 31 monotherapy and 20 drug-free patients. Compared with drug-free patients, patients receiving antipsychotic drugs demonstrated significant increases in theta, alpha and beta power. When patients taking different types of antipsychotics were compared with drug-free patients, we found no significant change in any spectrum power for the aripiprazole or blonanserin groups. Patients taking risperidone demonstrated significant increases in alpha and beta power. Patients taking clozapine and olanzapine demonstrated significant slow wave increases. Multiple regression analysis revealed that the chlorpromazine equivalent dose was positively associated with theta power. CONCLUSION Use of any antipsychotic drug by patients was associated with a dose-dependent increase in theta power. However, each type of antipsychotic demonstrated different spectral power changes.
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Affiliation(s)
- Takashi Ozaki
- Department of Psychiatry, Graduate School of Medicine, Hokkaido University, Sapporo, Japan.,Department of Psychiatry, Hokkaido Prefectural Koyogaoka Hospital, Sapporo, Japan
| | - Atsuhito Toyomaki
- Department of Psychiatry, Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Naoki Hashimoto
- Department of Psychiatry, Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Ichiro Kusumi
- Department of Psychiatry, Graduate School of Medicine, Hokkaido University, Sapporo, Japan
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10
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Arora M, Knott VJ, Labelle A, Fisher DJ. Alterations of Resting EEG in Hallucinating and Nonhallucinating Schizophrenia Patients. Clin EEG Neurosci 2021; 52:159-167. [PMID: 33074718 DOI: 10.1177/1550059420965385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Auditory hallucinations (AHs) are a common symptom of schizophrenia and contribute significantly to disease burden. Research on schizophrenia and AHs is limited and fails to adequately address the effect of AHs on resting EEG in patients with schizophrenia. This study assessed changes in frequency bands (delta, theta, alpha, beta) of resting EEG taken from hallucinating patients (n = 12), nonhallucinating patients (n = 11), and healthy controls (n = 12). Delta and theta activity were unaffected by AHs but differed between patients with schizophrenia and healthy controls. Alpha activity was affected by AHs: nonhallucinators had more alpha activity than hallucinators and healthy controls. Additionally, beta activity was inversely related to trait measures of AHs. These findings contribute to the literature of resting eyes closed EEG recordings of schizophrenia and AHs, and indicate the role of delta, theta, alpha, and beta as markers for schizophrenia and auditory hallucinations.
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Affiliation(s)
- Madhav Arora
- Faculty of Medicine, 6363University of Ottawa, Ottawa, Ontario, Canada
| | - Verner J Knott
- Faculty of Medicine, 6363University of Ottawa, Ottawa, Ontario, Canada
- The 26624Royal's Institute of Mental Health Research, Ottawa, Ontario, Canada
| | - Alain Labelle
- Faculty of Medicine, 6363University of Ottawa, Ottawa, Ontario, Canada
- The 26624Royal's Institute of Mental Health Research, Ottawa, Ontario, Canada
| | - Derek J Fisher
- The 26624Royal's Institute of Mental Health Research, Ottawa, Ontario, Canada
- Department of Psychology, Mount Saint Vincent University, Halifax, Nova Scotia, Canada
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11
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Racz FS, Farkas K, Stylianou O, Kaposzta Z, Czoch A, Mukli P, Csukly G, Eke A. Separating scale-free and oscillatory components of neural activity in schizophrenia. Brain Behav 2021; 11:e02047. [PMID: 33538105 PMCID: PMC8119820 DOI: 10.1002/brb3.2047] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 12/07/2020] [Accepted: 01/08/2021] [Indexed: 12/14/2022] Open
Abstract
INTRODUCTION Alterations in narrow-band spectral power of electroencephalography (EEG) recordings are commonly reported in patients with schizophrenia (SZ). It is well established however that electrophysiological signals comprise a broadband scale-free (or fractal) component generated by mechanisms different from those producing oscillatory neural activity. Despite this known feature, it has not yet been investigated if spectral abnormalities found in SZ could be attributed to scale-free or oscillatory brain function. METHODS In this study, we analyzed resting-state EEG recordings of 14 SZ patients and 14 healthy controls. Scale-free and oscillatory components of the power spectral density (PSD) were separated, and band-limited power (BLP) of the original (mixed) PSD, as well as its fractal and oscillatory components, was estimated in five frequency bands. The scaling property of the fractal component was characterized by its spectral exponent in two distinct frequency ranges (1-13 and 13-30 Hz). RESULTS Analysis of the mixed PSD revealed a decrease of BLP in the delta band in SZ over the central regions; however, this difference could be attributed almost exclusively to a shift of power toward higher frequencies in the fractal component. Broadband neural activity expressed a true bimodal nature in all except frontal regions. Furthermore, both low- and high-range spectral exponents exhibited a characteristic topology over the cortex in both groups. CONCLUSION Our results imply strong functional significance of scale-free neural activity in SZ and suggest that abnormalities in PSD may emerge from alterations of the fractal and not only the oscillatory components of neural activity.
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Affiliation(s)
| | - Kinga Farkas
- Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest, Hungary
| | | | - Zalan Kaposzta
- Department of Physiology, Semmelweis University, Budapest, Hungary
| | - Akos Czoch
- Department of Physiology, Semmelweis University, Budapest, Hungary
| | - Peter Mukli
- Department of Physiology, Semmelweis University, Budapest, Hungary
| | - Gabor Csukly
- Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest, Hungary
| | - Andras Eke
- Department of Physiology, Semmelweis University, Budapest, Hungary
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12
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Clementz BA, Trotti RL, Pearlson GD, Keshavan MS, Gershon ES, Keedy SK, Ivleva EI, McDowell JE, Tamminga CA. Testing Psychosis Phenotypes From Bipolar-Schizophrenia Network for Intermediate Phenotypes for Clinical Application: Biotype Characteristics and Targets. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2020; 5:808-818. [PMID: 32600898 DOI: 10.1016/j.bpsc.2020.03.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Psychiatry aspires to the molecular understanding of its disorders and, with that knowledge, to precision medicine. Research supporting such goals in the dimension of psychosis has been compromised, in part, by using phenomenology alone to estimate disease entities. To this end, we are proponents of a deep phenotyping approach in psychosis, using computational strategies to discover the most informative phenotypic fingerprint as a promising strategy to uncover mechanisms in psychosis. METHODS Doing this, the Bipolar-Schizophrenia Network for Intermediate Phenotypes (B-SNIP) has used biomarkers to identify distinct subtypes of psychosis with replicable biomarker characteristics. While we have presented these entities as relevant, their potential utility in clinical practice has not yet been demonstrated. RESULTS Here we carried out an analysis of clinical features that characterize biotypes. We found that biotypes have unique and defining clinical characteristics that could be used as initial screens in the clinical and research settings. Differences in these clinical features appear to be consistent with biotype biomarker profiles, indicating a link between biological features and clinical presentation. Clinical features associated with biotypes differ from those associated with DSM diagnoses, indicating that biotypes and DSM syndromes are not redundant and are likely to yield different treatment predictions. We highlight 3 predictions based on biotype that are derived from individual biomarker features and cannot be obtained from DSM psychosis syndromes. CONCLUSIONS In the future, biotypes may prove to be useful for targeting distinct molecular, circuit, cognitive, and psychosocial therapies for improved functional outcomes.
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Affiliation(s)
- Brett A Clementz
- Departments of Psychology and Neuroscience, Bio-Imaging Research Center, University of Georgia, Athens, Georgia
| | - Rebekah L Trotti
- Departments of Psychology and Neuroscience, Bio-Imaging Research Center, University of Georgia, Athens, Georgia
| | - Godfrey D Pearlson
- Olin Neuropsychiatry Research Center, Institute of Living at Hartford Hospital, Hartford, Connecticut; Department of Psychiatry, Yale University, New Haven, Connecticut
| | - Matcheri S Keshavan
- Department of Psychiatry, Beth Israel Deaconess, Harvard Medical School, Boston, Massachusetts
| | - Elliot S Gershon
- Department of Psychiatry, University of Chicago, Chicago, Illinois
| | - Sarah K Keedy
- Department of Psychiatry, University of Chicago, Chicago, Illinois
| | - Elena I Ivleva
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Jennifer E McDowell
- Departments of Psychology and Neuroscience, Bio-Imaging Research Center, University of Georgia, Athens, Georgia
| | - Carol A Tamminga
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas.
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13
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Racz FS, Stylianou O, Mukli P, Eke A. Multifractal and Entropy-Based Analysis of Delta Band Neural Activity Reveals Altered Functional Connectivity Dynamics in Schizophrenia. Front Syst Neurosci 2020; 14:49. [PMID: 32792917 PMCID: PMC7394222 DOI: 10.3389/fnsys.2020.00049] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 06/29/2020] [Indexed: 12/14/2022] Open
Abstract
Dynamic functional connectivity (DFC) was established in the past decade as a potent approach to reveal non-trivial, time-varying properties of neural interactions – such as their multifractality or information content –, that otherwise remain hidden from conventional static methods. Several neuropsychiatric disorders were shown to be associated with altered DFC, with schizophrenia (SZ) being one of the most intensely studied among such conditions. Here we analyzed resting-state electroencephalography recordings of 14 SZ patients and 14 age- and gender-matched healthy controls (HC). We reconstructed dynamic functional networks from delta band (0.5–4 Hz) neural activity and captured their spatiotemporal dynamics in various global network topological measures. The acquired network measure time series were made subject to dynamic analyses including multifractal analysis and entropy estimation. Besides group-level comparisons, we built a classifier to explore the potential of DFC features in classifying individual cases. We found stronger delta-band connectivity, as well as increased variance of DFC in SZ patients. Surrogate data testing verified the true multifractal nature of DFC in SZ, with patients expressing stronger long-range autocorrelation and degree of multifractality when compared to controls. Entropy analysis indicated reduced temporal complexity of DFC in SZ. When using these indices as features, an overall cross-validation accuracy surpassing 89% could be achieved in classifying individual cases. Our results imply that dynamic features of DFC such as its multifractal properties and entropy are potent markers of altered neural dynamics in SZ and carry significant potential not only in better understanding its pathophysiology but also in improving its diagnosis. The proposed framework is readily applicable for neuropsychiatric disorders other than schizophrenia.
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Affiliation(s)
| | | | - Peter Mukli
- Department of Physiology, Semmelweis University, Budapest, Hungary
| | - Andras Eke
- Department of Physiology, Semmelweis University, Budapest, Hungary
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14
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Zhao Z, Wang C, Yuan Q, Zhao J, Ren Q, Xu Y, Li J, Yu Y. Dynamic changes of brain networks during feedback-related processing of reinforcement learning in schizophrenia. Brain Res 2020; 1746:146979. [PMID: 32544500 DOI: 10.1016/j.brainres.2020.146979] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 06/01/2020] [Accepted: 06/09/2020] [Indexed: 12/28/2022]
Abstract
Previous studies have reported that schizophrenia (SZ) patients showed selective reinforcement learning deficits and abnormal feedback-related event-related potential (ERP) components. However, how the brain networks and their topological properties evolve over time during transient feedback-related cognition processing in SZ patients has not been investigated so far. In this paper, using publicly available feedback-related ERP data which were recorded from SZ patients and healthy controls (HC) when they performed a reinforcement learning task, we carried out an event-related network analysis where topology of brain functional networks was characterized with some graph measures including clustering coefficient (C), global efficiency (Eglobal) and local efficiency (Elocal) on a millisecond timescale. Our results showed that the brain functional networks displayed rapid rearrangements of topological properties during transient feedback-related cognition process for both two groups. More importantly, we found that SZ patients exhibited significantly reduced theta-band (time window of 170-350 ms after stimuli onset) brain functional connectivity strength, Eglobal, Elocal and C in response to negative feedback stimuli compared to HC group. The network based statistic (NBS) analysis detected one significantly decreased theta-band subnetwork in SZ patients mainly involving in frontal-occipital and temporal-occipital connections compared to HC group. In addition, clozapine treatment seemed to greatly reduce theta-band power and topological measures of brain networks in SZ patients. Finally, the theta-band power, graph measures and functional connectivity were extracted to train a support vector machine classifier for classification of HC from SZ, or Cloz + SZ or Cloz- SZ, and a relatively good classification accuracy of 84.48%, 89.47% and 78.26% was obtained, respectively. The above results suggested a less optimal organization of theta-band brain network in SZ patients, and studying the topological parameters of brain networks evolve over time during transient feedback-related processing could be useful for understanding the pathophysiologic mechanisms underlying reinforcement learning deficits in SZ patients.
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Affiliation(s)
- Zongya Zhao
- School of Medical Engineering, Xinxiang Medical University, Xinxiang 453003, PR China; Engineering Technology Research Center of Neurosense and Control of Xinxiang City, Xinxiang 453003, PR China; Xinxiang Key Laboratory of Biomedical Information Research, Henan Engineering Laboratory of Combinatorial Technique for Clinical and Biomedical Big Data, Xinxiang 453003, PR China.
| | - Chang Wang
- School of Medical Engineering, Xinxiang Medical University, Xinxiang 453003, PR China; Engineering Technology Research Center of Neurosense and Control of Xinxiang City, Xinxiang 453003, PR China; Xinxiang Key Laboratory of Biomedical Information Research, Henan Engineering Laboratory of Combinatorial Technique for Clinical and Biomedical Big Data, Xinxiang 453003, PR China
| | - Qingli Yuan
- School of Medical Engineering, Xinxiang Medical University, Xinxiang 453003, PR China
| | - Junqiang Zhao
- School of Medical Engineering, Xinxiang Medical University, Xinxiang 453003, PR China; Engineering Technology Research Center of Neurosense and Control of Xinxiang City, Xinxiang 453003, PR China; Xinxiang Key Laboratory of Biomedical Information Research, Henan Engineering Laboratory of Combinatorial Technique for Clinical and Biomedical Big Data, Xinxiang 453003, PR China
| | - Qiongqiong Ren
- School of Medical Engineering, Xinxiang Medical University, Xinxiang 453003, PR China; Engineering Technology Research Center of Neurosense and Control of Xinxiang City, Xinxiang 453003, PR China; Xinxiang Key Laboratory of Biomedical Information Research, Henan Engineering Laboratory of Combinatorial Technique for Clinical and Biomedical Big Data, Xinxiang 453003, PR China
| | - Yongtao Xu
- School of Medical Engineering, Xinxiang Medical University, Xinxiang 453003, PR China; Engineering Technology Research Center of Neurosense and Control of Xinxiang City, Xinxiang 453003, PR China; Xinxiang Key Laboratory of Biomedical Information Research, Henan Engineering Laboratory of Combinatorial Technique for Clinical and Biomedical Big Data, Xinxiang 453003, PR China
| | - Jie Li
- Department of Neurology, The First Affiliated Hospital of Xinxiang Medical University, Weihui 453100, Henan Province, China
| | - Yi Yu
- School of Medical Engineering, Xinxiang Medical University, Xinxiang 453003, PR China; Engineering Technology Research Center of Neurosense and Control of Xinxiang City, Xinxiang 453003, PR China; Xinxiang Key Laboratory of Biomedical Information Research, Henan Engineering Laboratory of Combinatorial Technique for Clinical and Biomedical Big Data, Xinxiang 453003, PR China.
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15
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Abnormalities of regional homogeneity and its correlation with clinical symptoms in Naïve patients with first-episode schizophrenia. Brain Imaging Behav 2019; 13:503-513. [PMID: 29736883 DOI: 10.1007/s11682-018-9882-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Several resting-state neuroimaging studies have indicated abnormal regional homogeneity (ReHo) in chronic schizophrenia; however, little work has been conducted to investigate naïve patients with first-episode schizophrenia (FES). Even less investigated is the association between ReHo measures and clinical symptom severity in naïve patients with FES. The current study evaluated ReHo alterations in whole brain, and assessed the correlations between ReHo measures and clinical variables in naïve patients with FES. Forty-four naïve patients with FES and 26 healthy controls (HC) underwent resting-state functional magnetic resonance imaging (rs-fMRI). Group-level analysis was utilized to analyze the ReHo differences between FES and HC in a voxel-by-voxel manner. Severity of symptoms was evaluated using a five-factor model of the Positive and Negative Syndrome Scale (PANSS). The correlation between the severity of symptoms and ReHo map was examined in patients using voxel-wise correlation analyses within brain areas that showed a significant ReHo alteration in patients compared with controls. Compared with the healthy control group, the FES group showed a significant decrease in ReHo values in the left medial frontal gyrus (MFG), right precentral gyrus, left superior temporal gyrus (STG), left left middle temporal gyrus (MTG), left thalamus, and significant increase in ReHo values in the left MFG, left inferior parietal lobule (IPL), left precuneus, and right lentiform nucleus (LN). In addition, the correlation analysis showed the PANSS total score negatively correlated with ReHo in the right precentral gyrus and positively correlated with ReHo in the left thalamus, the positive factor positively correlated with ReHo in the right thalamus, the disorganized/concrete factor positively correlated with ReHo in left posterior cingulate gyrus (PCG), the excited factor positively correlated with ReHo in the left precuneus, and the depressed factor negatively correlated with ReHo in the right postcentral gyrus and positively correlated with ReHo in the right thalamus. Our results indicate that widespread ReHo abnormalities occurred in an early stage of schizophrenic onset, suggesting a potential neural basis for the pathogenesis and symptomatology of schizophrenia.
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16
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Schulz S, Haueisen J, Bär KJ, Voss A. Altered Causal Coupling Pathways within the Central-Autonomic-Network in Patients Suffering from Schizophrenia. ENTROPY 2019; 21:e21080733. [PMID: 33267447 PMCID: PMC7515262 DOI: 10.3390/e21080733] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/19/2019] [Accepted: 07/24/2019] [Indexed: 12/28/2022]
Abstract
The multivariate analysis of coupling pathways within physiological (sub)systems focusing on identifying healthy and diseased conditions. In this study, we investigated a part of the central-autonomic-network (CAN) in 17 patients suffering from schizophrenia (SZO) compared to 17 age–gender matched healthy controls (CON) applying linear and nonlinear causal coupling approaches (normalized short time partial directed coherence, multivariate transfer entropy). Therefore, from all subjects continuous heart rate (successive beat-to-beat intervals, BBI), synchronized maximum successive systolic blood pressure amplitudes (SYS), synchronized calibrated respiratory inductive plethysmography signal (respiratory frequency, RESP), and the power PEEG of frontal EEG activity were investigated for 15 min under resting conditions. The CAN revealed a bidirectional coupling structure, with central driving towards blood pressure (SYS), and respiratory driving towards PEEG. The central-cardiac, central-vascular, and central-respiratory couplings are more dominated by linear regulatory mechanisms than nonlinear ones. The CAN showed significantly weaker nonlinear central-cardiovascular and central-cardiorespiratory coupling pathways, and significantly stronger linear central influence on the vascular system, and on the other hand significantly stronger linear respiratory and cardiac influences on central activity in SZO compared to CON, and thus, providing better understanding of the interrelationship of central and autonomic regulatory mechanisms in schizophrenia might be useful as a biomarker of this disease.
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Affiliation(s)
- Steffen Schulz
- Institute of Innovative Health Technologies, University of Applied Sciences, 07745 Jena, Germany
| | - Jens Haueisen
- Institute of Biomedical Engineering and Informatics, University of Technology, 98693 Ilmenau, Germany
| | - Karl-Jürgen Bär
- Department of Psychiatry and Psychotherapy, Pain and Autonomics-Integrative Research, University Hospital, 07745 Jena, Germany
| | - Andreas Voss
- Institute of Innovative Health Technologies, University of Applied Sciences, 07745 Jena, Germany
- Correspondence: ; Tel.: +49-3641-205625
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17
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Newson JJ, Thiagarajan TC. EEG Frequency Bands in Psychiatric Disorders: A Review of Resting State Studies. Front Hum Neurosci 2019; 12:521. [PMID: 30687041 PMCID: PMC6333694 DOI: 10.3389/fnhum.2018.00521] [Citation(s) in RCA: 319] [Impact Index Per Article: 63.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 12/11/2018] [Indexed: 12/19/2022] Open
Abstract
A significant proportion of the electroencephalography (EEG) literature focuses on differences in historically pre-defined frequency bands in the power spectrum that are typically referred to as alpha, beta, gamma, theta and delta waves. Here, we review 184 EEG studies that report differences in frequency bands in the resting state condition (eyes open and closed) across a spectrum of psychiatric disorders including depression, attention deficit-hyperactivity disorder (ADHD), autism, addiction, bipolar disorder, anxiety, panic disorder, post-traumatic stress disorder (PTSD), obsessive compulsive disorder (OCD) and schizophrenia to determine patterns across disorders. Aggregating across all reported results we demonstrate that characteristic patterns of power change within specific frequency bands are not necessarily unique to any one disorder but show substantial overlap across disorders as well as variability within disorders. In particular, we show that the most dominant pattern of change, across several disorder types including ADHD, schizophrenia and OCD, is power increases across lower frequencies (delta and theta) and decreases across higher frequencies (alpha, beta and gamma). However, a considerable number of disorders, such as PTSD, addiction and autism show no dominant trend for spectral change in any direction. We report consistency and validation scores across the disorders and conditions showing that the dominant result across all disorders is typically only 2.2 times as likely to occur in the literature as alternate results, and typically with less than 250 study participants when summed across all studies reporting this result. Furthermore, the magnitudes of the results were infrequently reported and were typically small at between 20% and 30% and correlated weakly with symptom severity scores. Finally, we discuss the many methodological challenges and limitations relating to such frequency band analysis across the literature. These results caution any interpretation of results from studies that consider only one disorder in isolation, and for the overall potential of this approach for delivering valuable insights in the field of mental health.
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18
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Howells FM, Temmingh HS, Hsieh JH, van Dijen AV, Baldwin DS, Stein DJ. Electroencephalographic delta/alpha frequency activity differentiates psychotic disorders: a study of schizophrenia, bipolar disorder and methamphetamine-induced psychotic disorder. Transl Psychiatry 2018; 8:75. [PMID: 29643331 PMCID: PMC5895848 DOI: 10.1038/s41398-018-0105-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 11/29/2017] [Accepted: 12/13/2017] [Indexed: 11/17/2022] Open
Abstract
Electroencephalography (EEG) has been proposed as a neurophysiological biomarker to delineate psychotic disorders. It is known that increased delta and decreased alpha, which are apparent in psychosis, are indicative of inappropriate arousal state, which leads to reduced ability to attend to relevant information. On this premise, we investigated delta/alpha frequency activity, as this ratio of frequency activity may serve as an effective neurophysiological biomarker. The current study investigated differences in delta/alpha frequency activity, in schizophrenia (SCZ), bipolar I disorder with psychotic features and methamphetamine-induced psychosis. One hundred and nine participants, including individuals with SCZ (n = 28), bipolar I disorder with psychotic features (n = 28), methamphetamine-induced psychotic disorder (MPD) (n = 24) and healthy controls (CON, n = 29). Diagnosis was ascertained with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th Edition disorders and current medication was recorded. EEG was undertaken in three testing conditions: resting eyes open, resting eyes closed and during completion of a simple cognitive task (visual continuous performance task). EEG delta/alpha frequency activity was investigated across these conditions. First, delta/alpha frequency activity during resting eyes closed was higher in SCZ and MPD globally, when compared to CON, then lower for bipolar disorder (BPD) than MPD for right hemisphere. Second, delta/alpha frequency activity during resting eyes open was higher in SCZ, BPD and MPD for all electrodes, except left frontal, when compared to CON. Third, delta/alpha frequency activity during the cognitive task was higher in BPD and MPD for all electrodes, except left frontal, when compared to CON. Assessment of EEG delta/alpha frequency activity supports the delineation of underlying neurophysiological mechanisms present in psychotic disorders, which are likely related to dysfunctional thalamo-cortical connectivity. Delta/alpha frequency activity may provide a useful neurophysiological biomarker to delineate psychotic disorders.
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Affiliation(s)
- Fleur M Howells
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa.
- Neuroscience Institute, University of Cape Town, Cape Town, South Africa.
| | - Hendrik S Temmingh
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
| | - Jennifer H Hsieh
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
| | - Andrea V van Dijen
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
| | - David S Baldwin
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
- Clinical and Experimental Sciences, University of Southampton, Southampton, UK
| | - Dan J Stein
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
- Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- MRC Unit on Risk and Resilience in Mental Disorders, Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
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19
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D'Agostino A, Castelnovo A, Cavallotti S, Casetta C, Marcatili M, Gambini O, Canevini M, Tononi G, Riedner B, Ferrarelli F, Sarasso S. Sleep endophenotypes of schizophrenia: slow waves and sleep spindles in unaffected first-degree relatives. NPJ SCHIZOPHRENIA 2018; 4:2. [PMID: 29426848 PMCID: PMC5807540 DOI: 10.1038/s41537-018-0045-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 12/18/2017] [Accepted: 01/16/2018] [Indexed: 11/09/2022]
Abstract
Sleep spindles and slow waves are the main brain oscillations occurring in non-REM sleep. Several lines of evidence suggest that spindles are initiated within the thalamus, whereas slow waves are generated and modulated in the cortex. A decrease in sleep spindle activity has been described in Schizophrenia (SCZ), including chronic, early course, and early onset patients. In contrast, slow waves have been inconsistently found to be reduced in SCZ, possibly due to confounds like duration of illness and antipsychotic medication exposure. Nontheless, the implication of sleep spindles and slow waves in the neurobiology of SCZ and related disorders, including their heritability, remains largely unknown. Unaffected first-degree relatives (FDRs) share a similar genetic background and several neurophysiological and cognitive deficits with SCZ patients, and allow testing whether some of these measures are candidate endophenotypes. In this study, we performed sleep high-density EEG recordings to characterise the spatiotemporal features of sleep spindles and slow waves in FDRs of SCZ probands and healthy subjects (HS) with no family history of SCZ. We found a significant reduction of integrated spindle activity (ISAs) in FDRs relative to HS, whereas spindle density and spindle duration were not different between groups. FDRs also had decreased slow wave amplitude and slopes. Altogether, our results suggest that ISAs deficits might represent a candidate endophenotype for SCZ. Furthermore, given the slow wave deficits observed in FDRs, we propose that disrupted cortical synchronisation increases the risk for SCZ, but thalamic dysfunction is necessary for the disorder to fully develop.
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Affiliation(s)
- Armando D'Agostino
- Department of Health Sciences, University of Milan, Milan, Italy. .,Department of Mental Health, San Paolo Hospital, Milan, Italy.
| | - Anna Castelnovo
- Department of Health Sciences, University of Milan, Milan, Italy
| | | | - Cecilia Casetta
- Department of Health Sciences, University of Milan, Milan, Italy
| | - Matteo Marcatili
- Department of Health Sciences, University of Milan, Milan, Italy
| | - Orsola Gambini
- Department of Health Sciences, University of Milan, Milan, Italy.,Department of Mental Health, San Paolo Hospital, Milan, Italy
| | - Mariapaola Canevini
- Department of Health Sciences, University of Milan, Milan, Italy.,Department of Mental Health, San Paolo Hospital, Milan, Italy
| | - Giulio Tononi
- Department of Psychiatry, University of Wisconsin, Madison, USA
| | - Brady Riedner
- Department of Psychiatry, University of Wisconsin, Madison, USA
| | - Fabio Ferrarelli
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, USA
| | - Simone Sarasso
- 'L. Sacco' Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy.
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20
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Castelnovo A, Graziano B, Ferrarelli F, D'Agostino A. Sleep spindles and slow waves in schizophrenia and related disorders: main findings, challenges and future perspectives. Eur J Neurosci 2018; 48:2738-2758. [PMID: 29280209 DOI: 10.1111/ejn.13815] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 12/03/2017] [Accepted: 12/18/2017] [Indexed: 01/24/2023]
Abstract
Sleep abnormalities have recently gained renewed attention in patients diagnosed with schizophrenia. Disrupted thalamocortical brain oscillations hold promise as putative biomarkers or endophenotypes of the disorder. Despite an increase in studies related to sleep spindle and slow-wave activity, findings remain in part contradictory. Although sleep spindle deficits have been confirmed in several groups of patients with chronic, medicated schizophrenia, data on the early stages of the disorder and in unmedicated subjects are still insufficient. Findings on slow-wave abnormalities are largely inconclusive, possibly due to the different criteria employed to define the phenomenon and to the influence of atypical antipsychotics. In this review, we aim to address the methodological and practical issues that may have limited the consistency of findings across research groups and different patient populations. Given the neurobiological relevance of these oscillations, which reflect the integrity of thalamocortical and cortico-cortical function, research in this domain should be encouraged. To promote widespread consensus over the scientific and clinical implications of these sleep-related phenomena, we advocate uniform and sound methodological approaches. These should encompass electroencephalographic recording and analysis techniques but also selection criteria and characterization of clinical populations.
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Affiliation(s)
- Anna Castelnovo
- Department of Health Sciences, Università degli Studi di Milano, via Antonio di Rudinì 8, 20142, Milan, Italy
| | - Bianca Graziano
- Department of Health Sciences, Università degli Studi di Milano, via Antonio di Rudinì 8, 20142, Milan, Italy.,Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Fabio Ferrarelli
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Armando D'Agostino
- Department of Health Sciences, Università degli Studi di Milano, via Antonio di Rudinì 8, 20142, Milan, Italy
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21
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Won GH, Kim JW, Choi TY, Lee YS, Min KJ, Seol KH. Theta-phase gamma-amplitude coupling as a neurophysiological marker in neuroleptic-naïve schizophrenia. Psychiatry Res 2018; 260:406-411. [PMID: 29253805 DOI: 10.1016/j.psychres.2017.12.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 10/25/2017] [Accepted: 12/09/2017] [Indexed: 02/03/2023]
Abstract
Theta-phase gamma-amplitude coupling (TGC) was used as an evidence-based tool to reflect the dysfunctional cortico-thalamic interaction in patients with schizophrenia. The aim of the present study was to evaluate the diagnostic utility of TGC. The subjects included 90 patients with schizophrenia and 90 healthy controls. We compared the TGC results between the groups using an analysis of covariance (ANCOVA) to adjust for age and sex and receiver operator characteristic (ROC) curve analyses to examine the discrimination ability of delta to gamma frequency bands and TGC. Patients with schizophrenia showed a significant increase in the resting-state TGC at all 19 electrodes. The analysis of the ROC curves for each frequency band exhibited relatively low classification accuracies for the delta, theta, slow alpha, fast alpha, and beta power. The TGC generated the most accurate results among the electroencephalography (EEG) measures, with an overall classification accuracy of 92.5%. The resting-state TGC value was increased in patients with schizophrenia compared to that in healthy controls and had a higher discriminating ability than the other parameters. These findings may be related to the compensatory hyper-arousal patterns of the dysfunctional default-mode network (DMN) in schizophrenia. Therefore, resting-state TGC is a promising neurophysiological marker of schizophrenia.
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Affiliation(s)
- Geun Hui Won
- Department of Psychiatry, Catholic University of Daegu School of Medicine, Daegu, Republic of Korea
| | - Jun Won Kim
- Department of Psychiatry, Catholic University of Daegu School of Medicine, Daegu, Republic of Korea.
| | - Tae Young Choi
- Department of Psychiatry, Catholic University of Daegu School of Medicine, Daegu, Republic of Korea
| | - Young Sik Lee
- Department of Psychiatry, Chung-Ang University, College of Medicine, Seoul, Republic of Korea
| | - Kyung Joon Min
- Department of Psychiatry, Chung-Ang University, College of Medicine, Seoul, Republic of Korea
| | - Ki Ho Seol
- Department of Radiation Oncology, Catholic University of Daegu School of Medicine, Daegu, Republic of Korea
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22
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Grin-Yatsenko VA, Ponomarev VA, Pronina MV, Poliakov YI, Plotnikova IV, Kropotov JD. Local and Widely Distributed EEG Activity in Schizophrenia With Prevalence of Negative Symptoms. Clin EEG Neurosci 2017; 48:307-315. [PMID: 28056537 DOI: 10.1177/1550059416683283] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We evaluated EEG frequency abnormalities in resting state (eyes closed and eyes open) EEG in a group of chronic schizophrenia patients as compared with healthy subjects. The study included 3 methods of analysis of deviation of EEG characteristics: genuine EEG, current source density (CSD), and group independent component (gIC). All 3 methods have shown that the EEG in schizophrenia patients is characterized by enhanced low-frequency (delta and theta) and high-frequency (beta) activity in comparison with the control group. However, the spatial pattern of differences was dependent on the type of method used. Comparative analysis has shown that increased EEG power in schizophrenia patients apparently concerns both widely spatially distributed components and local components of signal. Furthermore, the observed differences in the delta and theta range can be described mainly by the local components, and those in the beta range mostly by spatially widely distributed ones. The possible nature of the widely distributed activity is discussed.
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Affiliation(s)
- Vera A Grin-Yatsenko
- 1 Laboratory of Neurobiology of Action Programming, N.P. Bechtereva Institute of the Human Brain of the Russian Academy of Sciences, St Petersburg, Russia
| | - Valery A Ponomarev
- 1 Laboratory of Neurobiology of Action Programming, N.P. Bechtereva Institute of the Human Brain of the Russian Academy of Sciences, St Petersburg, Russia
| | - Marina V Pronina
- 1 Laboratory of Neurobiology of Action Programming, N.P. Bechtereva Institute of the Human Brain of the Russian Academy of Sciences, St Petersburg, Russia
| | - Yury I Poliakov
- 1 Laboratory of Neurobiology of Action Programming, N.P. Bechtereva Institute of the Human Brain of the Russian Academy of Sciences, St Petersburg, Russia
| | - Irina V Plotnikova
- 1 Laboratory of Neurobiology of Action Programming, N.P. Bechtereva Institute of the Human Brain of the Russian Academy of Sciences, St Petersburg, Russia
| | - Juri D Kropotov
- 1 Laboratory of Neurobiology of Action Programming, N.P. Bechtereva Institute of the Human Brain of the Russian Academy of Sciences, St Petersburg, Russia.,2 Institute of Psychology, Norwegian University of Science and Technology, Trondheim, Norway.,3 Department of Neuropsychology, Andrzej Frycz Modrzewski Krakow University, Krakow, Poland
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23
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Erickson MA, Albrecht MA, Robinson B, Luck SJ, Gold JM. Impaired suppression of delay-period alpha and beta is associated with impaired working memory in schizophrenia. BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2017; 2:272-279. [PMID: 28670630 DOI: 10.1016/j.bpsc.2016.09.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
BACKGROUND Although people with schizophrenia (PSZ) frequently exhibit reduced working memory capacity relative to healthy comparison subjects (HCS), the mechanisms that underlie this impairment are not yet known. The present study aimed to assess one putative mechanism: impaired suppression of alpha and beta frequency bands during the delay period of a visual working memory task. METHODS The electroencephalogram (EEG) was recorded from 30 PSZ and 31 HCS while they completed a change detection task in which they were required to remember a briefly presented array of colored squares over an 1800-ms delay interval. RESULTS Overall, we found that PSZ had significantly reduced alpha and beta-band suppression during the delay interval compared to HCS, and that these significant differences emerged early (100-200 ms after the onset of the memory array). Furthermore, the magnitude of suppression was significantly associated with task performance across both groups. Finally, the magnitude of suppression in alpha and beta frequency bands was significantly associated with a range of cognitive measures among HCS, but not PSZ. CONCLUSIONS These results implicate impaired alpha/beta suppression during the consolidation period of working memory tasks as a promising neural mechanism that constrains capacity in PSZ.
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Affiliation(s)
| | - Matthew A Albrecht
- Maryland Psychiatric Research Center, University of Maryland.,School of Public Health, Curtin University, Perth, Australia
| | | | - Steven J Luck
- Center for Mind and Brain, University of California, Davis
| | - James M Gold
- Maryland Psychiatric Research Center, University of Maryland
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24
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Identification of Schizophrenia Using EEG Alpha Band Power During Hyperventilation and Post-hyperventilation. J Med Biol Eng 2016. [DOI: 10.1007/s40846-016-0192-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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25
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de la Salle S, Choueiry J, Shah D, Bowers H, McIntosh J, Ilivitsky V, Knott V. Effects of Ketamine on Resting-State EEG Activity and Their Relationship to Perceptual/Dissociative Symptoms in Healthy Humans. Front Pharmacol 2016; 7:348. [PMID: 27729865 PMCID: PMC5037139 DOI: 10.3389/fphar.2016.00348] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 09/15/2016] [Indexed: 11/13/2022] Open
Abstract
N-methyl-D-aspartate (NMDA) receptor antagonists administered to healthy humans results in schizophrenia-like symptoms, which preclinical research suggests are due to glutamatergically altered brain oscillations. Here, we examined resting-state electroencephalographic activity in 21 healthy volunteers assessed in a placebo-controlled, double-blind, randomized study involving administration of either a saline infusion or a sub-anesthetic dose of ketamine, an NMDA receptor antagonist. Frequency-specific current source density (CSD) was assessed at sensor-level and source-level using eLORETA within regions of interest of a triple network model of schizophrenia (this model posits a dysfunctional switching between large-scale Default Mode and Central Executive networks by the monitor-controlling Salience Network). These CSDs were measured in each session along with subjective symptoms as indexed with the Clinician Administered Dissociative States Scale. Ketamine-induced CSD reductions in slow (delta/theta and alpha) and increases in fast (gamma) frequencies at scalp electrode sites were paralleled by frequency-specific CSD changes in the Default Mode, Central Executive, and Salience networks. Subjective symptoms scores were increased with ketamine and ratings of depersonalization in particular were associated with alpha CSD reductions in general and in specific regions of interest in each of the three networks. These results tentatively support the hypothesis that pathological brain oscillations associated with hypofunctional NMDA receptor activity may contribute to the emergence of the perceptual/dissociate symptoms of schizophrenia.
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Affiliation(s)
| | - Joelle Choueiry
- Department of Cellular and Molecular Medicine, University of Ottawa Ottawa, ON, Canada
| | - Dhrasti Shah
- School of Psychology, University of Ottawa Ottawa, ON, Canada
| | - Hayley Bowers
- Department of Psychology, University of Guelph Guelph, ON, Canada
| | - Judy McIntosh
- University of Ottawa Institute of Mental Health Research Ottawa, ON, Canada
| | - Vadim Ilivitsky
- Department of Psychiatry, University of OttawaOttawa, ON, Canada; Royal Ottawa Mental Health CentreOttawa, ON, Canada
| | - Verner Knott
- School of Psychology, University of OttawaOttawa, ON, Canada; Department of Cellular and Molecular Medicine, University of OttawaOttawa, ON, Canada; University of Ottawa Institute of Mental Health ResearchOttawa, ON, Canada; Department of Psychiatry, University of OttawaOttawa, ON, Canada
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26
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Aiyer R, Novakovic V, Barkin RL. A systematic review on the impact of psychotropic drugs on electroencephalogram waveforms in psychiatry. Postgrad Med 2016; 128:656-64. [DOI: 10.1080/00325481.2016.1218261] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Rohit Aiyer
- Department of Psychiatry, Hofstra Northwell Health, Staten Island University Hospital, Staten Island, NY, USA
| | - Vladan Novakovic
- Department of Psychiatry, Hofstra Northwell Health, Staten Island University Hospital, Staten Island, NY, USA
| | - Robert L. Barkin
- Department of Anesthesiology, Family Medicine & Pharmacology, Rush Medical College, North Shore University Health System Evanston and Skokie Hospital, Chicago, IL, USA
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27
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Electrophysiological alterations in a complex rat model of schizophrenia. Behav Brain Res 2016; 307:65-72. [DOI: 10.1016/j.bbr.2016.03.051] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 03/25/2016] [Accepted: 03/29/2016] [Indexed: 12/17/2022]
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28
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Mouchlianitis E, McCutcheon R, Howes OD. Brain-imaging studies of treatment-resistant schizophrenia: a systematic review. Lancet Psychiatry 2016; 3:451-63. [PMID: 26948188 PMCID: PMC5796640 DOI: 10.1016/s2215-0366(15)00540-4] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 11/22/2015] [Accepted: 11/23/2015] [Indexed: 02/05/2023]
Abstract
Around 30% of patients with schizophrenia show an inadequate response to antipsychotics-ie, treatment resistance. Neuroimaging studies can help to uncover the underlying neurobiological reasons for such resistance and identify these patients earlier. Additionally, studies examining the effect of clozapine on the brain can help to identify aspects of clozapine that make it uniquely effective in patients with treatment resistance. We did a systematic search of PubMed between Jan 1, 1980, and April 13, 2015, to identify all neuroimaging studies that examined treatment-resistant patients or longitudinally assessed the effects of clozapine treatment. We identified 330 articles, of which 61 met the inclusion criteria. Replicated differences between treatment-resistant and treatment-responsive patients include reductions in grey matter and perfusion of frontotemporal regions, and increases in white matter and basal ganglia perfusion, with effect sizes ranging from 0·4 to greater than 1. Clozapine treatment led to reductions in caudate nucleus volume in three separate studies. The available evidence supports the hypothesis that some of the neurobiological changes seen in treatment-resistant schizophrenia lie along a continuum with treatment-responsive schizophrenia, whereas other differences are categorical in nature and have potential to be used as biomarkers. However, further replication is needed, and for neuroimaging findings to be clinically translatable, future studies need to focus on a-priori hypotheses and be adequately powered.
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Affiliation(s)
- Elias Mouchlianitis
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, London, UK
| | - Robert McCutcheon
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, London, UK; Psychiatric Imaging Group, Medical Research Council Clinical Sciences Centre, Institute of Clinical Science, Imperial College London, London, UK.
| | - Oliver D Howes
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, London, UK; Psychiatric Imaging Group, Medical Research Council Clinical Sciences Centre, Institute of Clinical Science, Imperial College London, London, UK
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29
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Albrecht MA, Waltz JA, Cavanagh JF, Frank MJ, Gold JM. Reduction of Pavlovian Bias in Schizophrenia: Enhanced Effects in Clozapine-Administered Patients. PLoS One 2016; 11:e0152781. [PMID: 27044008 PMCID: PMC4833478 DOI: 10.1371/journal.pone.0152781] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 03/19/2016] [Indexed: 11/18/2022] Open
Abstract
The negative symptoms of schizophrenia (SZ) are associated with a pattern of reinforcement learning (RL) deficits likely related to degraded representations of reward values. However, the RL tasks used to date have required active responses to both reward and punishing stimuli. Pavlovian biases have been shown to affect performance on these tasks through invigoration of action to reward and inhibition of action to punishment, and may be partially responsible for the effects found in patients. Forty-five patients with schizophrenia and 30 demographically-matched controls completed a four-stimulus reinforcement learning task that crossed action ("Go" or "NoGo") and the valence of the optimal outcome (reward or punishment-avoidance), such that all combinations of action and outcome valence were tested. Behaviour was modelled using a six-parameter RL model and EEG was simultaneously recorded. Patients demonstrated a reduction in Pavlovian performance bias that was evident in a reduced Go bias across the full group. In a subset of patients administered clozapine, the reduction in Pavlovian bias was enhanced. The reduction in Pavlovian bias in SZ patients was accompanied by feedback processing differences at the time of the P3a component. The reduced Pavlovian bias in patients is suggested to be due to reduced fidelity in the communication between striatal regions and frontal cortex. It may also partially account for previous findings of poorer "Go-learning" in schizophrenia where "Go" responses or Pavlovian consistent responses are required for optimal performance. An attenuated P3a component dynamic in patients is consistent with a view that deficits in operant learning are due to impairments in adaptively using feedback to update representations of stimulus value.
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Affiliation(s)
- Matthew A. Albrecht
- Maryland Psychiatric Research Center, Department of Psychiatry, School of
Medicine, University of Maryland, Baltimore, Maryland, United States of
America
- School of Public Health, Faculty of Health Sciences, Curtin University,
Perth, Western Australia, Australia
- Curtin Health Innovation Research Institute—Biosciences, Curtin
University, Perth, Western Australia, Australia
- * E-mail: ;
| | - James A. Waltz
- Maryland Psychiatric Research Center, Department of Psychiatry, School of
Medicine, University of Maryland, Baltimore, Maryland, United States of
America
| | - James F. Cavanagh
- Department of Psychology, University of New Mexico, Albuquerque, New
Mexico, United States of America
| | - Michael J. Frank
- Department of Cognitive, Linguistic and Psychological Sciences, Brown
University, Providence, Rhode Island, United States of America
- Department of Psychiatry and Brown Institute for Brain Science, Brown
University, Providence, Rhode Island, United States of America
| | - James M. Gold
- Maryland Psychiatric Research Center, Department of Psychiatry, School of
Medicine, University of Maryland, Baltimore, Maryland, United States of
America
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30
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Liu C, Xue Z, Palaniyappan L, Zhou L, Liu H, Qi C, Wu G, Mwansisya TE, Tao H, Chen X, Huang X, Liu Z, Pu W. Abnormally increased and incoherent resting-state activity is shared between patients with schizophrenia and their unaffected siblings. Schizophr Res 2016; 171:158-65. [PMID: 26805410 DOI: 10.1016/j.schres.2016.01.022] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 12/18/2015] [Accepted: 01/11/2016] [Indexed: 12/19/2022]
Abstract
BACKGROUND Several resting-state neuroimaging studies in schizophrenia indicate an excessive brain activity while others report an incoherent brain activity at rest. No direct evidence for the simultaneous presence of both excessive and incoherent brain activity has been established to date. Moreover, it is unclear whether unaffected siblings of schizophrenia patients who share half of the affected patient's genotype also exhibit the excessive and incoherent brain activity that may render them vulnerable to the development of schizophrenia. METHODS 27 pairs of schizophrenia patients and their unaffected siblings, as well as 27 healthy controls, were scanned using gradient-echo echo-planar imaging at rest. By using amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (Reho), we investigated the intensity and synchronization of local spontaneous neuronal activity in three groups. RESULTS We observed that increased amplitude and reduced synchronization (coherence) of spontaneous neuronal activity were shared by patients and their unaffected siblings. The key brain regions with this abnormal neural pattern in both patients and siblings included the middle temporal, orbito-frontal, inferior occipital and fronto-insular gyrus. CONCLUSIONS This abnormal neural pattern of excessive and incoherent neuronal activity shared by schizophrenia patients and their healthy siblings may improve our understanding of neuropathology and genetic predisposition in schizophrenia.
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Affiliation(s)
- Chang Liu
- Mental Health Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China; The China National Clinical Research Center for Mental Health Disorders, National Technology Institute of Psychiatry, Key Laboratory of Psychiatry and Mental Health of Hunan Province, 139 Middle Renmin Road, Changsha, Hunan 410011, People's Republic of China
| | - Zhimin Xue
- Mental Health Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China; State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, People's Republic of China; The China National Clinical Research Center for Mental Health Disorders, National Technology Institute of Psychiatry, Key Laboratory of Psychiatry and Mental Health of Hunan Province, 139 Middle Renmin Road, Changsha, Hunan 410011, People's Republic of China
| | - Lena Palaniyappan
- Departments of Psychiatry, Neuroscience and Medical Biophysics, University of Western Ontario, London, Ontario, Canada
| | - Li Zhou
- Mental Health Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China; The China National Clinical Research Center for Mental Health Disorders, National Technology Institute of Psychiatry, Key Laboratory of Psychiatry and Mental Health of Hunan Province, 139 Middle Renmin Road, Changsha, Hunan 410011, People's Republic of China
| | - Haihong Liu
- Mental Health Center, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Chang Qi
- Mental Health Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China; The China National Clinical Research Center for Mental Health Disorders, National Technology Institute of Psychiatry, Key Laboratory of Psychiatry and Mental Health of Hunan Province, 139 Middle Renmin Road, Changsha, Hunan 410011, People's Republic of China
| | - Guowei Wu
- Mental Health Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China; The China National Clinical Research Center for Mental Health Disorders, National Technology Institute of Psychiatry, Key Laboratory of Psychiatry and Mental Health of Hunan Province, 139 Middle Renmin Road, Changsha, Hunan 410011, People's Republic of China
| | - Tumbwene E Mwansisya
- Mental Health Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China; College of Health Sciences, University of Dodoma, P.O. Box 395, Dodoma, Tanzania
| | - Haojuan Tao
- Mental Health Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China; The China National Clinical Research Center for Mental Health Disorders, National Technology Institute of Psychiatry, Key Laboratory of Psychiatry and Mental Health of Hunan Province, 139 Middle Renmin Road, Changsha, Hunan 410011, People's Republic of China
| | - Xudong Chen
- Mental Health Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China; The China National Clinical Research Center for Mental Health Disorders, National Technology Institute of Psychiatry, Key Laboratory of Psychiatry and Mental Health of Hunan Province, 139 Middle Renmin Road, Changsha, Hunan 410011, People's Republic of China
| | - Xiaojun Huang
- Mental Health Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China; The China National Clinical Research Center for Mental Health Disorders, National Technology Institute of Psychiatry, Key Laboratory of Psychiatry and Mental Health of Hunan Province, 139 Middle Renmin Road, Changsha, Hunan 410011, People's Republic of China
| | - Zhening Liu
- Mental Health Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China; State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, People's Republic of China; The China National Clinical Research Center for Mental Health Disorders, National Technology Institute of Psychiatry, Key Laboratory of Psychiatry and Mental Health of Hunan Province, 139 Middle Renmin Road, Changsha, Hunan 410011, People's Republic of China
| | - Weidan Pu
- Medical Psychological Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China; The China National Clinical Research Center for Mental Health Disorders, National Technology Institute of Psychiatry, Key Laboratory of Psychiatry and Mental Health of Hunan Province, 139 Middle Renmin Road, Changsha, Hunan 410011, People's Republic of China.
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31
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Chaychi I, Foroughipour M, Haghir H, Talaei A, Chaichi A. Electroencephalographic characteristics of Iranian schizophrenia patients. Acta Neurol Belg 2015; 115:665-70. [PMID: 25651947 DOI: 10.1007/s13760-014-0415-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 12/17/2014] [Indexed: 12/01/2022]
Abstract
Schizophrenia is a prevalent psychiatric disease with heterogeneous causes that is diagnosed based on history and mental status examination. Applied electrophysiology is a non-invasive method to investigate the function of the involved brain areas. In a previously understudied population, we examined acute phase electroencephalography (EEG) records along with pertinent Positive and Negative Syndrome Scale (PANSS) and Mini Mental State Examination (MMSE) scores for each patient. Sixty-four hospitalized patients diagnosed to have schizophrenia in Ebn-e-Sina Hospital were included in this study. PANSS and MMSE were completed and EEG tracings for every patient were recorded. Also, EEG tracings were recorded for 64 matched individuals of the control group. Although the predominant wave pattern in both patients and controls was alpha, theta waves were almost exclusively found in eight (12.5 %) patients with schizophrenia. Pathological waves in schizophrenia patients were exclusively found in the frontal brain region, while identified pathological waves in controls were limited to the temporal region. No specific EEG finding supported laterality in schizophrenia patients. PANSS and MMSE scores were significantly correlated with specific EEG parameters (all P values <0.04). Patients with schizophrenia demonstrate specific EEG patterns and show a clear correlation between EEG parameters and PANSS and MMSE scores. These characteristics are not observed in all patients, which imply that despite an acceptable specificity, they are not applicable for the majority of schizophrenia patients. Any deduction drawn based on EEG and scoring systems is in need of larger studies incorporating more patients and using better functional imaging techniques for the brain.
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Affiliation(s)
- Irman Chaychi
- Psychiatry and Behavioral Sciences Research Center (PBSRC), Mashhad University of Medical Sciences (MUMS), Mashhad, Iran.
| | - Mohsen Foroughipour
- Department of Neurology, Ghaem Hospital, Mashhad University of Medical Sciences (MUMS), Mashhad, Iran
| | - Hossein Haghir
- Department of Anatomy and Cell Biology, School of Medicine, Mashhad University of Medical Sciences (MUMS), Mashhad, Iran
- Medical Genetic Research Center (MGRC), School of Medicine, Mashhad University of Medical Sciences (MUMS), Mashhad, Iran
| | - Ali Talaei
- Psychiatry and Behavioral Sciences Research Center (PBSRC), Journal of Fundamentals of Mental Health (JFMH), Mashhad University of Medical Sciences, Mashhad, Iran
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32
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Ranlund S, Adams RA, Díez Á, Constante M, Dutt A, Hall MH, Maestro Carbayo A, McDonald C, Petrella S, Schulze K, Shaikh M, Walshe M, Friston K, Pinotsis D, Bramon E. Impaired prefrontal synaptic gain in people with psychosis and their relatives during the mismatch negativity. Hum Brain Mapp 2015; 37:351-65. [PMID: 26503033 PMCID: PMC4843949 DOI: 10.1002/hbm.23035] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 09/30/2015] [Accepted: 10/13/2015] [Indexed: 12/11/2022] Open
Abstract
The mismatch negativity (MMN) evoked potential, a preattentive brain response to a discriminable change in auditory stimulation, is significantly reduced in psychosis. Glutamatergic theories of psychosis propose that hypofunction of NMDA receptors (on pyramidal cells and inhibitory interneurons) causes a loss of synaptic gain control. We measured changes in neuronal effective connectivity underlying the MMN using dynamic causal modeling (DCM), where the gain (excitability) of superficial pyramidal cells is explicitly parameterised. EEG data were obtained during a MMN task—for 24 patients with psychosis, 25 of their first‐degree unaffected relatives, and 35 controls—and DCM was used to estimate the excitability (modeled as self‐inhibition) of (source‐specific) superficial pyramidal populations. The MMN sources, based on previous research, included primary and secondary auditory cortices, and the right inferior frontal gyrus. Both patients with psychosis and unaffected relatives (to a lesser degree) showed increased excitability in right inferior frontal gyrus across task conditions, compared to controls. Furthermore, in the same region, both patients and their relatives showed a reversal of the normal response to deviant stimuli; that is, a decrease in excitability in comparison to standard conditions. Our results suggest that psychosis and genetic risk for the illness are associated with both context‐dependent (condition‐specific) and context‐independent abnormalities of the excitability of superficial pyramidal cell populations in the MMN paradigm. These abnormalities could relate to NMDA receptor hypofunction on both pyramidal cells and inhibitory interneurons, and appear to be linked to the genetic aetiology of the illness, thereby constituting potential endophenotypes for psychosis. Hum Brain Mapp 37:351–365, 2016. © 2015 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Siri Ranlund
- Division of Psychiatry, University College London, London, United Kingdom
| | - Rick A Adams
- Division of Psychiatry, University College London, London, United Kingdom.,Institute of Cognitive Neuroscience, University College London, London, United Kingdom
| | - Álvaro Díez
- Division of Psychiatry, University College London, London, United Kingdom
| | - Miguel Constante
- Department of Psychiatry, Hospital Beatriz Angelo, Lisbon, Portugal
| | - Anirban Dutt
- The South London and Maudsley NHS Foundation Trust, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom
| | - Mei-Hua Hall
- Psychology Research Laboratory, Harvard Medical School, McLean Hospital, Belmont, Massachusetts, USA
| | - Amparo Maestro Carbayo
- The South London and Maudsley NHS Foundation Trust, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom
| | - Colm McDonald
- Department of Psychiatry, Clinical Science Institute, National University of Ireland, Galway, Ireland
| | - Sabrina Petrella
- The South London and Maudsley NHS Foundation Trust, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom.,Department of Psychiatry, Clinical and Experimental Science Institute, University of Foggia, Italy
| | - Katja Schulze
- The South London and Maudsley NHS Foundation Trust, University Hospital Lewisham, London, United Kingdom
| | - Madiha Shaikh
- The South London and Maudsley NHS Foundation Trust, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom.,Neuroepidemiology and Ageing Research Unit, Imperial College, London, United Kingdom
| | - Muriel Walshe
- Division of Psychiatry, University College London, London, United Kingdom.,The South London and Maudsley NHS Foundation Trust, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom
| | - Karl Friston
- The Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, London, United Kingdom
| | - Dimitris Pinotsis
- The Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, London, United Kingdom
| | - Elvira Bramon
- Division of Psychiatry, University College London, London, United Kingdom.,Institute of Cognitive Neuroscience, University College London, London, United Kingdom.,The South London and Maudsley NHS Foundation Trust, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom
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33
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Goldstein MR, Peterson MJ, Sanguinetti JL, Tononi G, Ferrarelli F. Topographic deficits in alpha-range resting EEG activity and steady state visual evoked responses in schizophrenia. Schizophr Res 2015; 168:145-52. [PMID: 26159669 DOI: 10.1016/j.schres.2015.06.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 06/10/2015] [Accepted: 06/12/2015] [Indexed: 01/16/2023]
Abstract
Deficits in both resting alpha-range (8-12Hz) electroencephalogram (EEG) activity and steady state evoked potential (SSVEP) responses have been reported in schizophrenia. However, the topographic specificity of these effects, the relationship between resting EEG and SSVEP, as well as the impact of antipsychotic medication on these effects, have not been clearly delineated. The present study sought to address these questions with 256 channel high-density EEG recordings in a group of 13 schizophrenia patients, 13 healthy controls, and 10 non-schizophrenia patients with psychiatric diagnoses currently taking antipsychotic medication. At rest, the schizophrenia group demonstrated decreased alpha EEG power in frontal and occipital areas relative to healthy controls. With SSVEP stimulation centered in the alpha band (10Hz), but not with stimulation above (15Hz) or below (7Hz) this range, the occipital deficit in alpha power was partially reverted. However, the frontal deficit persisted and contributed to a significantly reduced topographic relationship between occipital and frontal alpha activity for resting EEG and 10Hz SSVEP alpha power in schizophrenia patients. No significant differences were observed between healthy and medicated controls or between medicated controls and schizophrenia. These findings suggest a potential intrinsic deficit in frontal eyes-closed EEG alpha oscillations in schizophrenia, whereby potent visual stimulation centered in that frequency range results in an increase in the occipital alpha power of these patients, which however does not extend to frontal regions. Future research to evaluate the cortical and subcortical mechanisms of these effects is warranted.
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Affiliation(s)
- Michael R Goldstein
- Department of Psychiatry, University of Wisconsin, Madison, WI, United States; Department of Psychology, University of Arizona, Tucson, AZ, United States
| | - Michael J Peterson
- Department of Psychiatry, University of Wisconsin, Madison, WI, United States
| | | | - Giulio Tononi
- Department of Psychiatry, University of Wisconsin, Madison, WI, United States
| | - Fabio Ferrarelli
- Department of Psychiatry, University of Wisconsin, Madison, WI, United States.
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34
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Bowers H, Smith D, de la Salle S, Choueiry J, Impey D, Philippe T, Dort H, Millar A, Daigle M, Albert PR, Beaudoin A, Knott V. COMT polymorphism modulates the resting-state EEG alpha oscillatory response to acute nicotine in male non-smokers. GENES, BRAIN, AND BEHAVIOR 2015; 14:466-76. [PMID: 26096691 PMCID: PMC4514526 DOI: 10.1111/gbb.12226] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 06/15/2015] [Accepted: 06/15/2015] [Indexed: 11/28/2022]
Abstract
Performance improvements in cognitive tasks requiring executive functions are evident with nicotinic acetylcholine receptor (nAChR) agonists, and activation of the underlying neural circuitry supporting these cognitive effects is thought to involve dopamine neurotransmission. As individual difference in response to nicotine may be related to a functional polymorphism in the gene encoding catechol-O-methyltransferase (COMT), an enzyme that strongly influences cortical dopamine metabolism, this study examined the modulatory effects of the COMT Val158Met polymorphism on the neural response to acute nicotine as measured with resting-state electroencephalographic (EEG) oscillations. In a sample of 62 healthy non-smoking adult males, a single dose (6 mg) of nicotine gum administered in a randomized, double-blind, placebo-controlled design was shown to affect α oscillatory activity, increasing power of upper α oscillations in frontocentral regions of Met/Met homozygotes and in parietal/occipital regions of Val/Met heterozygotes. Peak α frequency was also found to be faster with nicotine (vs. placebo) treatment in Val/Met heterozygotes, who exhibited a slower α frequency compared to Val/Val homozygotes. The data tentatively suggest that interindividual differences in brain α oscillations and their response to nicotinic agonist treatment are influenced by genetic mechanisms involving COMT.
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Affiliation(s)
- H. Bowers
- Department of Psychology, University of Guelph, Guelph, ON, Canada
| | - D. Smith
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - S. de la Salle
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - J. Choueiry
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - D. Impey
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - T. Philippe
- University of Ottawa Institute of Mental Health Research, Royal Ottawa Mental Health Care Centre, Ottawa, ON, Canada
| | - H. Dort
- University of Ottawa Institute of Mental Health Research, Royal Ottawa Mental Health Care Centre, Ottawa, ON, Canada
| | - A. Millar
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - M. Daigle
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - P. R. Albert
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - A. Beaudoin
- University of Ottawa Institute of Mental Health Research, Royal Ottawa Mental Health Care Centre, Ottawa, ON, Canada
| | - V. Knott
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
- University of Ottawa Institute of Mental Health Research, Royal Ottawa Mental Health Care Centre, Ottawa, ON, Canada
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Multivariate genetic determinants of EEG oscillations in schizophrenia and psychotic bipolar disorder from the BSNIP study. Transl Psychiatry 2015; 5:e588. [PMID: 26101851 PMCID: PMC4490286 DOI: 10.1038/tp.2015.76] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 04/27/2015] [Accepted: 05/04/2015] [Indexed: 01/18/2023] Open
Abstract
Schizophrenia (SZ) and psychotic bipolar disorder (PBP) are disabling psychiatric illnesses with complex and unclear etiologies. Electroencephalogram (EEG) oscillatory abnormalities in SZ and PBP probands are heritable and expressed in their relatives, but the neurobiology and genetic factors mediating these abnormalities in the psychosis dimension of either disorder are less explored. We examined the polygenic architecture of eyes-open resting state EEG frequency activity (intrinsic frequency) from 64 channels in 105 SZ, 145 PBP probands and 56 healthy controls (HCs) from the multisite BSNIP (Bipolar-Schizophrenia Network on Intermediate Phenotypes) study. One million single-nucleotide polymorphisms (SNPs) were derived from DNA. We assessed eight data-driven EEG frequency activity derived from group-independent component analysis (ICA) in conjunction with a reduced subset of 10,422 SNPs through novel multivariate association using parallel ICA (para-ICA). Genes contributing to the association were examined collectively using pathway analysis tools. Para-ICA extracted five frequency and nine SNP components, of which theta and delta activities were significantly correlated with two different gene components, comprising genes participating extensively in brain development, neurogenesis and synaptogenesis. Delta and theta abnormality was present in both SZ and PBP, while theta differed between the two disorders. Theta abnormalities were also mediated by gene clusters involved in glutamic acid pathways, cadherin and synaptic contact-based cell adhesion processes. Our data suggest plausible multifactorial genetic networks, including novel and several previously identified (DISC1) candidate risk genes, mediating low frequency delta and theta abnormalities in psychoses. The gene clusters were enriched for biological properties affecting neural circuitry and involved in brain function and/or development.
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A Novel Application of Multiscale Entropy in Electroencephalography to Predict the Efficacy of Acetylcholinesterase Inhibitor in Alzheimer's Disease. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2015; 2015:953868. [PMID: 26120358 PMCID: PMC4450304 DOI: 10.1155/2015/953868] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 01/02/2015] [Indexed: 11/30/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia. According to one hypothesis, AD is caused by the reduced synthesis of the neurotransmitter acetylcholine. Therefore, acetylcholinesterase (AChE) inhibitors are considered to be an effective therapy. For clinicians, however, AChE inhibitors are not a predictable treatment for individual patients. We aimed to disclose the difference by biosignal processing. In this study, we used multiscale entropy (MSE) analysis, which can disclose the embedded information in different time scales, in electroencephalography (EEG), in an attempt to predict the efficacy of AChE inhibitors. Seventeen newly diagnosed AD patients were enrolled, with an initial minimental state examination (MMSE) score of 18.8 ± 4.5. After 12 months of AChE inhibitor therapy, 7 patients were responsive and 10 patients were nonresponsive. The major difference between these two groups is Slope 2 (MSE6 to 20). The area below the receiver operating characteristic (ROC) curve of Slope 2 is 0.871 (95% CI = 0.69–1). The sensitivity is 85.7% and the specificity is 60%, whereas the cut-off value of Slope 2 is −0.024. Therefore, MSE analysis of EEG signals, especially Slope 2, provides a potential tool for predicting the efficacy of AChE inhibitors prior to therapy.
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Narayanan B, O’Neil K, Berwise C, Stevens MC, Calhoun VD, Clementz BA, Tamminga CA, Sweeney JA, Keshavan MS, Pearlson GD. Resting state electroencephalogram oscillatory abnormalities in schizophrenia and psychotic bipolar patients and their relatives from the bipolar and schizophrenia network on intermediate phenotypes study. Biol Psychiatry 2014; 76:456-65. [PMID: 24439302 PMCID: PMC5045030 DOI: 10.1016/j.biopsych.2013.12.008] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 12/11/2013] [Accepted: 12/12/2013] [Indexed: 01/27/2023]
Abstract
BACKGROUND Abnormal resting state electroencephalogram (EEG) oscillations are reported in schizophrenia (SZ) and bipolar disorder, illnesses with overlapping symptoms and genetic risk. However, less evidence exists on whether similar EEG spectral abnormalities are present in individuals with both disorders or whether these abnormalities are present in first-degree relatives, possibly representing genetic predisposition for these disorders. METHODS Investigators examined 64-channel resting state EEGs of 225 SZ probands and 201 first-degree relatives (SZR), 234 psychotic bipolar (PBP) probands and 231 first-degree relatives (PBPR), and 200 healthy control subjects. Eight independent resting state EEG spectral components and associated spatial weights were derived using group independent component analysis. Analysis of covariance was conducted on spatial weights to evaluate group differences. Relative risk estimates and familiality were evaluated on abnormal spectral profiles in probands and relatives. RESULTS Both SZ and PBP probands exhibited increased delta, theta, and slow and fast alpha activity. Post-hoc pair-wise comparison revealed increased frontocentral slow beta activity in SZ and PBP probands as well as SZR and PBPR. Augmented frontal delta activity was exhibited by SZ probands and SZR, whereas PBP probands and PBPR showed augmented fast alpha activity. CONCLUSIONS Both SZ and PBP probands demonstrated aberrant low-frequency activity. Slow beta activity was abnormal in SZ and PBP probands as well as SZR and PBPR perhaps indicating a common endophenotype for both disorders. Delta and fast alpha activity were unique endophenotypes for SZ and PBP probands, respectively. The EEG spectral activity exhibited moderate relative risk and heritability estimates, serving as intermediate phenotypes in future genetic studies for examining biological mechanisms underlying the pathogenesis of the two disorders.
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Affiliation(s)
- Balaji Narayanan
- Olin Neuropsychiatry Research Center, Hartford Hospital (IOL campus), Hartford, Connecticut.
| | - Kasey O’Neil
- Olin Neuropsychiatry Research Center, Hartford, CT-06106
| | | | | | | | | | - Carol A. Tamminga
- Department of Psychiatry, UT Southwestern Medical School, Dallas, TX 75390
| | - John A. Sweeney
- Department of Psychiatry, UT Southwestern Medical School, Dallas, TX 75390
| | - Matcheri S. Keshavan
- Department of Psychiatry, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA02215
| | - Godfrey D. Pearlson
- Olin Neuropsychiatry Research Center, Hartford, CT-06106,Departments of Psychiatry & Neurobiology, Yale University School of Medicine, New Haven, CT 06510
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Ravan M, Hasey G, Reilly JP, MacCrimmon D, Khodayari-Rostamabad A. A machine learning approach using auditory odd-ball responses to investigate the effect of Clozapine therapy. Clin Neurophysiol 2014; 126:721-30. [PMID: 25213349 DOI: 10.1016/j.clinph.2014.07.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 06/28/2014] [Accepted: 07/07/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVE To develop a machine learning (ML) methodology based on features extracted from odd-ball auditory evoked potentials to identify neurophysiologic changes induced by Clozapine (CLZ) treatment in responding schizophrenic (SCZ) subjects. This objective is of particular interest because CLZ, though a potentially dangerous drug, can be uniquely effective for otherwise medication-resistant SCZ subjects. We wish to determine whether ML methods can be used to identify a set of EEG-based discriminating features that can simultaneously (1) distinguish all the SCZ subjects before treatment (BT) from healthy volunteer (HV) subjects, (2) distinguish EEGs collected before CLZ treatment (BT) vs. those collected after treatment (AT) for those subjects most responsive to CLZ, (3) discriminate least responsive subjects from HV AT, and (4) no longer discriminate most responsive subjects from HVs AT. If a set of EEG-derived features satisfy these four conditions, then it may be concluded that these features normalize in responsive subjects as a result of CLZ treatment, and therefore potentially provide insight into the functioning of the drug on the SCZ brain. METHODS Odd-ball auditory evoked potentials of 66 HVs and 47 SCZ adults both BT and AT with CLZ were derived from EEG recordings. Treatment outcome, after at least one year follow-up, was assessed through clinical rating scores assigned by an experienced clinician, blind to EEG results. Using a criterion of at least 35% improvement after CLZ treatment, subjects were divided into "most-responsive" (MR) and "least-responsive" (LR) groups. As a first step, a brain source localization (BSL) procedure was employed on the EEG signals to extract source waveforms from specified brain regions. ML methods were then applied to these source waveform signals to determine whether a set of features satisfying the four conditions outlined above could be discovered. RESULTS A set of cross-power spectral density (CPSD) features meeting these criteria was identified. These CPSD features, consisting of a combination of brain regional source activity and connectivity measures, significantly overlap with the default mode network (DMN). All decrease with CLZ treatment in responding SCZs. CONCLUSIONS A set of EEG-derived discriminating features which normalize as a result of CLZ treatment was identified. These discriminating features define a network that shares significant commonality with the DMN. Our findings are consistent with those of previous literature, which suggest that regions of the DMN are hyperactive and hyperconnected in SCZ subjects. Our study shows that these discriminating features decrease after treatment, consistent with portions of the DMN normalizing with CLZ therapy in responsive subjects. SIGNIFICANCE Machine learning is proposed as a potentially powerful tool for analysis of the effect of medication on psychiatric illness. If replicated, the proposed approach could be used to gain some improved understanding of the effect of neuroleptic medications in treating psychotic illness. These results may also be useful in the development of new pharmaceuticals, since a new drug which induces changes in brain electrophysiology similar to those seen after CLZ could also have powerful antipsychotic properties.
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Affiliation(s)
- Maryam Ravan
- Department of Electrical and Computer Engineering, McMaster University, Hamilton, ON, Canada.
| | - Gary Hasey
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada
| | - James P Reilly
- Department of Electrical and Computer Engineering, McMaster University, Hamilton, ON, Canada
| | - Duncan MacCrimmon
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada
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Abeles IY, Gomez-Ramirez M. Impairments in background and event-related alpha-band oscillatory activity in patients with schizophrenia. PLoS One 2014; 9:e91720. [PMID: 24646909 PMCID: PMC3960158 DOI: 10.1371/journal.pone.0091720] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 02/14/2014] [Indexed: 11/28/2022] Open
Abstract
Studies show that patients with schizophrenia exhibit impaired responses to sensory stimuli, especially at the early stages of neural processing. In particular, patients' alpha-band (8-14 Hz) event-related desynchronization (ERD) and visual P1 event-related potential (ERP) component tend to be significantly reduced, with P1 ERP deficits greater for visual stimuli biased towards the magnocellular system. In healthy controls, studies show that pre-stimulus alpha (background alpha) plays a pivotal role in sensory processing and behavior, largely by shaping the neural responses to incoming stimuli. Here, we address whether patients' ERD and P1 deficits stem from impairments in pre-stimulus alpha mechanisms. To address this question we recorded electrophysiological activity in patients with schizophrenia and healthy controls while they engaged in a visual discrimination task with low, medium, and high contrast stimuli. The results revealed a significant decrease in patients' ERDs, which was largely driven by reductions in pre-stimulus alpha. These reductions were most prominent in right-hemispheric areas. We also observed a systematic relationship between pre-stimulus alpha and the P1 component across different contrast levels. However, this relationship was only observed in healthy controls. Taken together, these findings highlight a substantial anomaly in patients' amplitude-based alpha background activity over visual areas. The results provide further support that pre-stimulus alpha activity plays an active role in perception by modulating the neural responses to incoming sensory inputs, a mechanism that seems to be compromised in schizophrenia.
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Affiliation(s)
- Ilana Y. Abeles
- Program in Cognitive Neuroscience, Department of Psychology, The City College of the City University of New York, New York, New York, United States of America
- Program in Cognitive Neuroscience and Schizophrenia, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York, United States of America
| | - Manuel Gomez-Ramirez
- Program in Cognitive Neuroscience, Department of Psychology, The City College of the City University of New York, New York, New York, United States of America
- The Zanvyl Krieger Mind Brain Institute, The Johns Hopkins University, Baltimore, Maryland, United States of America
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Ranlund S, Nottage J, Shaikh M, Dutt A, Constante M, Walshe M, Hall MH, Friston K, Murray R, Bramon E. Resting EEG in psychosis and at-risk populations--a possible endophenotype? Schizophr Res 2014; 153:96-102. [PMID: 24486144 PMCID: PMC3969576 DOI: 10.1016/j.schres.2013.12.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 11/25/2013] [Accepted: 12/27/2013] [Indexed: 01/05/2023]
Abstract
BACKGROUND Finding reliable endophenotypes for psychosis could lead to an improved understanding of aetiology, and provide useful alternative phenotypes for genetic association studies. Resting quantitative electroencephalography (QEEG) activity has been shown to be heritable and reliable over time. However, QEEG research in patients with psychosis has shown inconsistent and even contradictory findings, and studies of at-risk populations are scarce. Hence, this study aimed to investigate whether resting QEEG activity represents a candidate endophenotype for psychosis. METHOD QEEG activity at rest was compared in four frequency bands (delta, theta, alpha, and beta), between chronic patients with psychosis (N=48), first episode patients (N=46), at-risk populations ("at risk mental state", N=33; healthy relatives of patients, N=45), and healthy controls (N=107). RESULTS Results showed that chronic patients had significantly increased resting QEEG amplitudes in delta and theta frequencies compared to healthy controls. However, first episode patients and at-risk populations did not differ from controls in these frequency bands. There were no group differences in alpha or beta frequency bands. CONCLUSION Since no abnormalities were found in first episode patients, ARMS, or healthy relatives, resting QEEG activity in the frequency bands examined is unlikely to be related to genetic predisposition to psychosis. Rather than endophenotypes, the low frequency abnormalities observed in chronic patients are probably related to illness progression and/or to the long-term effects of treatments.
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Affiliation(s)
- Siri Ranlund
- Mental Health Sciences Unit & Institute of Cognitive Neuroscience, University College London, W1W 7EJ, United Kingdom.
| | - Judith Nottage
- NIHR Biomedical Research Centre for Mental Health at the South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, Kings College London, WC2R 2LS, United Kingdom
| | - Madiha Shaikh
- NIHR Biomedical Research Centre for Mental Health at the South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, Kings College London, WC2R 2LS, United Kingdom; Department of Psychology, Royal Holloway, University of London, TW20 0EX, United Kingdom
| | - Anirban Dutt
- NIHR Biomedical Research Centre for Mental Health at the South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, Kings College London, WC2R 2LS, United Kingdom
| | - Miguel Constante
- Psychiatry Department, Hospital Beatriz Ângelo, 2674-514 Loures, Lisbon, Portugal
| | - Muriel Walshe
- Mental Health Sciences Unit & Institute of Cognitive Neuroscience, University College London, W1W 7EJ, United Kingdom; NIHR Biomedical Research Centre for Mental Health at the South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, Kings College London, WC2R 2LS, United Kingdom
| | - Mei-Hua Hall
- Psychology Research Laboratory, Harvard Medical School, McLean Hospital, Belmont, MA 02478, USA
| | - Karl Friston
- The Wellcome Trust Centre for Neuroimaging, University College London, WC1N 3BG, United Kingdom
| | - Robin Murray
- NIHR Biomedical Research Centre for Mental Health at the South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, Kings College London, WC2R 2LS, United Kingdom
| | - Elvira Bramon
- Mental Health Sciences Unit & Institute of Cognitive Neuroscience, University College London, W1W 7EJ, United Kingdom; NIHR Biomedical Research Centre for Mental Health at the South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, Kings College London, WC2R 2LS, United Kingdom
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Shrivastava A, Johnston M, Shah N, Stitt L, Shrivastava S, Sousa AD. Clozapine response and pre-treatment EEG-is there some kind of relationship. Ind Psychiatry J 2014; 23:18-22. [PMID: 25535440 PMCID: PMC4261208 DOI: 10.4103/0972-6748.144951] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Clozapine has been used widely in the management of treatment-resistant schizophrenia. The present study aims at determining whether pre-treatment electroencephalography (EEG) abnormalities would serve as a marker for response to clozapine treatment. SUBJECTS AND METHODS This was a cross-sectional study done in a tertiary care center in Mumbai where patients diagnosed with schizophrenia using DSM-IV criteria and resistant schizophrenia using Kane criteria were assessed using EEG prior to starting clozapine treatment. They were rated for symptomatic improvement using the Positive and Negative Syndrome Scale (PANSS) along with Clinical Global Improvement for Severity (CGI-S). The results were statistically analysed and presented. RESULTS 55 out of the 80 patients in the study showed baseline EEG abnormalities. The mean duration of illness in the patients were 2.65 years. Slow wave and background EEG abnormalities were common in pre-treatment EEG. 36.4% patients in the study showed clinical response. Patients with negative symptoms and baseline EEG abnormalities showed better response. CONCLUSIONS The study was circumscribed and had many limitations due to a small sample size. The relation between pre-treatment EEG abnormalities and clozapine response could not be statistically correlated and it could not be ascertained to be a marker for response to clozapine therapy.
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Affiliation(s)
- Amresh Shrivastava
- Department of Psychiatry, Elgin Early Intervention Program for Psychosis, The University of Western Ontario, Ontario, Canada ; Mental Health Resource Foundation, Mumbai, Maharashtra, India
| | - Megan Johnston
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada
| | - Nilesh Shah
- Department of Psychiatry, Lokmanya Tilak Municipal Medical College, Mumbai, Maharashtra, India
| | - Larry Stitt
- Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Shivanshu Shrivastava
- Department of Psychiatry, Lokmanya Tilak Municipal Medical College, Mumbai, Maharashtra, India
| | - Avinash De Sousa
- Department of Psychiatry, Lokmanya Tilak Municipal Medical College, Mumbai, Maharashtra, India
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Suazo V, Díez Á, Martín C, Ballesteros A, Casado P, Martín-Loeches M, Molina V. Elevated noise power in gamma band related to negative symptoms and memory deficit in schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2012; 38:270-5. [PMID: 22549114 DOI: 10.1016/j.pnpbp.2012.04.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 04/11/2012] [Accepted: 04/11/2012] [Indexed: 12/21/2022]
Abstract
BACKGROUND There is an increasing consideration for a disorganized cerebral activity in schizophrenia, perhaps relating to a synaptic inhibitory deficit in the illness. Noise power (scalp-recorded electroencephalographic activity unlocked to stimuli) may offer a non-invasive window to assess this possibility. METHODS 29 minimally-treated patients with schizophrenia (of which 17 were first episodes) and 27 healthy controls underwent clinical and cognitive assessments and an electroencephalographic recording during a P300 paradigm to calculate signal-to-noise ratio and noise power magnitudes in the theta and gamma bands. RESULTS In comparison to controls, a significantly higher gamma noise power was common to minimally-treated and first episode patients over P3, P4, T5 and Fz electrode sites. Those high values were directly correlated to negative symptom severity and inversely correlated to verbal memory scores in the patients. There were no differences in signal-to-noise ratio magnitudes among the groups. Gamma noise power at Fz discriminated significantly between patients and controls. No significant differences were found in theta noise power or in gamma noise power over the other electrode sites between the groups of patients and controls. LIMITATIONS We have not assessed phase-locked and non-phase locked power changes, a complementary approach that may yield useful information. CONCLUSIONS Gamma noise power may represent a useful and non-invasive tool for studying brain dysfunction in psychotic illness. These results suggest an inefficient activation pattern in schizophrenia.
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Affiliation(s)
- Vanessa Suazo
- Institute for Biomedical Research of Salamanca (IBSAL), Spain.
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Maccrimmon D, Brunet D, Criollo M, Galin H, Lawson JS. Clozapine augments delta, theta, and right frontal EEG alpha power in schizophrenic patients. ISRN PSYCHIATRY 2012; 2012:596486. [PMID: 23738206 PMCID: PMC3658574 DOI: 10.5402/2012/596486] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 01/30/2012] [Indexed: 11/23/2022]
Abstract
Objective. To explore the Quantitative EEG (QEEG) effects of established clozapine therapy regimes compared to those of previous ineffective antipsychotic regimes among 64 chronic (DSM-IV) schizophrenic patients. Methods. Data from 20 EEG channels referenced to linked ears were collected before and during maintenance clozapine therapy (mean duration 1.4 years). Absolute power was calculated in six frequency bands: delta (0.4–3.6 Hz), theta (4.2–7.8 Hz), alpha (8.2–11.8 Hz), beta1 (12.2–15.8 Hz), beta2 (16.2–19.8 Hz), and beta3 (20.2–23.8 Hz). Results. Clozapine augments power globally in the delta and theta bands, but this effect is more pronounced over frontal areas. Beta3 power was reduced. Alpha showed a frontal increase, more pronounced in the right, coupled with a posterior decrease with no net change in overall power. Conclusion. The demonstration of a significant clozapine-induced alpha topographic shift frontally and to the right is a novel discovery that may serve to encourage further investigations of subcortical structures in attempts to better understand the diverse aetiologies and optimal treatments of the schizophrenias.
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Affiliation(s)
- D Maccrimmon
- Department of Psychiatry, McMaster University, Hamilton, ON, Canada L8S 4L8 ; St. Joseph's Mountain Healthcare Services, 100 West 5th Street, Hamilton, ON, Canada L8N 3K7
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Hyun J, Baik MJ, Kang UG. Effects of Psychotropic Drugs on Quantitative EEG among Patients with Schizophrenia-spectrum Disorders. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE 2011; 9:78-85. [PMID: 23429185 PMCID: PMC3569080 DOI: 10.9758/cpn.2011.9.2.78] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 08/04/2011] [Accepted: 08/06/2011] [Indexed: 11/18/2022]
Abstract
OBJECTIVE We examined how psychotropic medications affected quantitative EEG (qEEG) results among patients with a schizophrenia-spectrum disorder. METHODS The drugs were clustered into nine groups depending on their mechanism. We hypothesized that drugs would affect the relative power shown in qEEG results independently and investigated the effect of each drug group on relative power using multiple linear regression analysis and independent samples t-tests. RESULTS We found that antipsychotics other than clozapine induced an increase in the relative power of alpha activity. Clozapine markedly increased slow waves and decreased alpha activity in the occipital area. The main findings for antidepressants and antiepileptic drugs were the beta increment and lithium increased the power of delta and theta activity. However, we found no evident changes in power due to benzodiazepine. CONCLUSION Our results are generally consistent with previous pharmaco-EEG studies, despite some differences. Therefore, the EEG effect in each drug group could be singled out even under the polypharmacy condition, with the possible exception of benzodiazepines. Our results support using a new methodological approach to identify the qEEG effects of various psychotropic drugs in clinical settings.
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Affiliation(s)
- June Hyun
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Korea
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Abstract
OBJECTIVE Clozapine treatment remains the gold standard for treatment-resistant schizophrenia, but treatment with clozapine is associated with several side-effects that complicate the use of the drug. This clinical overview aims to provide psychiatrists with knowledge about how to optimize clozapine treatment. Relevant strategies for reducing side-effects and increasing the likelihood of response are discussed. METHOD Studies of clozapine available in MEDLINE were reviewed. RESULTS A slow up-titration of clozapine is recommended in order to reach the optimal dosage of clozapine and diminish the risk of dose-dependent side-effects. Particularly, in case of partial response or non-response, the use of therapeutic drug monitoring of clozapine is recommended. Plasma levels above the therapeutic threshold of 350-420 ng/ml are necessary to determine non-response to clozapine. To ease the burden of dose-dependent side-effects, dose reduction of clozapine should be tried and combination with another antipsychotic drug may facilitate further dose reduction. For most side-effects, counteracting medication exists. Augmentation with lamotrigine, antipsychotics, or electroconvulsive therapy may be beneficial in case of partial response to clozapine. CONCLUSION Treatment with clozapine should be optimized in order to increase the rate of response and to minimize side-effects, thus diminishing the risk of discontinuation and psychotic relapse.
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Affiliation(s)
- J Nielsen
- Unit for Psychiatric Research, Aalborg Psychiatric Hospital, Aarhus University Hospital, Denmark.
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Siekmeier PJ, Stufflebeam SM. Patterns of spontaneous magnetoencephalographic activity in patients with schizophrenia. J Clin Neurophysiol 2010; 27:179-90. [PMID: 20461010 PMCID: PMC3665947 DOI: 10.1097/wnp.0b013e3181e0b20a] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Magnetoencephalography noninvasively measures the magnetic fields produced by the brain. Pertinent research articles from 1993 to 2009 that measured spontaneous, whole-head magnetoencephalography activity in patients with schizophrenia were reviewed. Data on localization of oscillatory activity and correlation of these findings with psychotic symptoms are summarized. Although the variety of measures used by different research groups makes a quantitative meta-analysis difficult, it appears that magnetoencephalography activity in patients may exhibit identifiable patterns, defined by topographic organization and frequency band. Specifically, 11 of the 12 studies showed increased theta (4-8 Hz) and delta (1-4 Hz) band oscillations in the temporal lobes of patients; of the 10 studies that examined the relationship between oscillatory activity and symptomatology, 8 found a positive correlation between temporal lobe theta activity and positive schizophrenic symptoms. Abnormally high frontal delta activity was not seen. These findings are analyzed in comparison with the electroencephalogram literature on schizophrenics, and possible confounds (e.g., medication effects) are discussed. In the future, magnetoencephalography might be used to assist in diagnosis or might be fruitfully used in conjunction with new neuroscience research approaches such as computational modeling, which may be able to link oscillatory activity and cellular-level pathology.
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Affiliation(s)
- Peter J Siekmeier
- Harvard Medical School and McLean Hospital, Belmont, Massachusetts 02478, USA.
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Hong LE, Summerfelt A, Buchanan RW, O'Donnell P, Thaker GK, Weiler MA, Lahti AC. Gamma and delta neural oscillations and association with clinical symptoms under subanesthetic ketamine. Neuropsychopharmacology 2010; 35:632-40. [PMID: 19890262 PMCID: PMC3055615 DOI: 10.1038/npp.2009.168] [Citation(s) in RCA: 183] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Several electrical neural oscillatory abnormalities have been associated with schizophrenia, although the underlying mechanisms of these oscillatory problems are unclear. Animal studies suggest that one of the key mechanisms of neural oscillations is through glutamatergic regulation; therefore, neural oscillations may provide a valuable animal-clinical interface on studying glutamatergic dysfunction in schizophrenia. To identify glutamatergic control of neural oscillation relevant to human subjects, we studied the effects of ketamine, an N-methyl-D-aspartate antagonist that can mimic some clinical aspects of schizophrenia, on auditory-evoked neural oscillations using a paired-click paradigm. This was a double-blind, placebo-controlled, crossover study of ketamine vs saline infusion on 10 healthy subjects. Clinically, infusion of ketamine in subanesthetic dose significantly increased thought disorder, withdrawal-retardation, and dissociative symptoms. Ketamine significantly augmented high-frequency oscillations (gamma band at 40-85 Hz, p=0.006) and reduced low-frequency oscillations (delta band at 1-5 Hz, p<0.001) compared with placebo. Importantly, the combined effect of increased gamma and reduced delta frequency oscillations was significantly associated with more withdrawal-retardation symptoms experienced during ketamine administration (p=0.02). Ketamine also reduced gating of the theta-alpha (5-12 Hz) range oscillation, an effect that mimics previously described deficits in schizophrenia patients and their first-degree relatives. In conclusion, acute ketamine appeared to mimic some aspects of neural oscillatory deficits in schizophrenia, and showed an opposite effect on scalp-recorded gamma vs low-frequency oscillations. These electrical oscillatory indexes of subanesthetic ketamine can be potentially used to cross-examine glutamatergic pharmacological effects in translational animal and human studies.
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Affiliation(s)
- L Elliot Hong
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD 21228, USA.
| | - Ann Summerfelt
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Robert W Buchanan
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Patricio O'Donnell
- Department of Anatomy and Neurobiology and Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Gunvant K Thaker
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Martin A Weiler
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Adrienne C Lahti
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA,Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
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Zhang Y, Llinas RR, Lisman JE. Inhibition of NMDARs in the Nucleus Reticularis of the Thalamus Produces Delta Frequency Bursting. Front Neural Circuits 2009; 3:20. [PMID: 20057928 PMCID: PMC2802545 DOI: 10.3389/neuro.04.020.2009] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Accepted: 10/23/2009] [Indexed: 01/18/2023] Open
Abstract
Injection of NMDAR antagonist into the thalamus can produce delta frequency EEG oscillations in the thalamocortical system. It is surprising that an antagonist of an excitatory neurotransmitter should trigger such activity, and the mechanism is unknown. One hypothesis is that the antagonist blocks excitation of GABAergic cells, thus producing disinhibition. To test this hypothesis, we investigated the effect of NMDAR antagonist (APV) on cells of the nucleus reticularis (nRT) in rat brain slices, a thalamic nucleus that can serve as a pacemaker for thalamocortical delta oscillations and that is composed entirely of GABAergic neurons. We found, unexpectedly, that nRT cells are hyperpolarized by APV. This occurs because these cells have an unusual form of NMDAR (probably NR2C) that contributes inward current at resting potential in response to ambient glutamate. The hyperpolarization produced by APV is sufficient to deinactivate T-type calcium channels, and these trigger rhythmic bursting at delta frequency. The APV-induced delta frequency bursting is abolished by dopamine D2 receptor antagonist, indicating that dopamine and NMDAR antagonist work synergistically to stimulate delta frequency bursting. Our results have significant implications concerning the electrophysiological basis of schizophrenia and bring together the NMDAR hypofunction, dopamine, and GABA theories of the disease. Our results suggest that NMDAR hypofunction and dopamine work synergistically on the GABAergic cells of the nRT to generate the delta frequency EEG oscillations, a thalamocortical dysrhythmia (TCD) in the awake state that is an established abnormality in schizophrenia.
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Affiliation(s)
- Yuchun Zhang
- Department of Biology and Volen Center for Complex Systems, Brandeis UniversityWaltham, MA, USA
| | - Rodolfo R. Llinas
- Department of Physiology and Neuroscience, New York University School of MedicineNew York, NY, USA
| | - John E. Lisman
- Department of Biology and Volen Center for Complex Systems, Brandeis UniversityWaltham, MA, USA
- *Correspondence: John E. Lisman, Department of Biology and Volen Center for Complex Systems, Brandeis University, MS 008, 415 South Street, Waltham, MA 02454, USA. e-mail:
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Alexander DM, Flynn GJ, Wong W, Whitford TJ, Harris AWF, Galletly CA, Silverstein SM. Spatio-temporal EEG waves in first episode schizophrenia. Clin Neurophysiol 2009; 120:1667-82. [PMID: 19646922 DOI: 10.1016/j.clinph.2009.06.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Revised: 06/18/2009] [Accepted: 06/25/2009] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Schizophrenia is characterized by a deficit in context processing, with physiological correlates of hypofrontality and reduced amplitude P3b event-related potentials. We hypothesized an additional physiological correlate: differences in the spatio-temporal dynamics of cortical activity along the anterior-posterior axis of the scalp. METHODS This study assessed latency topographies of spatio-temporal waves under task conditions that elicit the P3b. EEG was recorded during separate auditory and visual tasks. Event-related spatio-temporal waves were quantified from scalp EEG of subjects with first episode schizophrenia (FES) and matched controls. RESULTS The P3b-related task conditions elicited a peak in spatio-temporal waves in the delta band at a similar latency to the P3b event-related potential. Subjects with FES had fewer episodes of anterior to posterior waves in the 2-4 Hz band compared to controls. Within the FES group, a tendency for fewer episodes of anterior to posterior waves was associated with high Psychomotor Poverty symptom factor scores. CONCLUSIONS Subjects with FES had altered global EEG dynamics along the anterior-posterior axis during task conditions involving context update. SIGNIFICANCE The directional nature of this finding and its association with Psychomotor Poverty suggest this result is related to findings of hypofrontality in schizophrenia.
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Affiliation(s)
- David M Alexander
- Laboratory for Perceptual Dynamics, RIKEN Brain Science Institute, Japan.
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Venables NC, Bernat EM, Sponheim SR. Genetic and disorder-specific aspects of resting state EEG abnormalities in schizophrenia. Schizophr Bull 2009; 35:826-39. [PMID: 18381357 PMCID: PMC2696373 DOI: 10.1093/schbul/sbn021] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
We evaluated whether abnormal frequency composition of the resting state electroencephalogram (EEG) in schizophrenia was associated with genetic liability for the disorder by studying first-degree biological relatives of schizophrenia patients. The study included a data-driven method for defining EEG frequency components and determined the specificity of resting state EEG frequency abnormalities by assessing schizophrenia patients, bipolar disorder patients, and relatives of both patient groups. Schizophrenia patients and their relatives, but not bipolar patients or their relatives, exhibited increased high-frequency activity (beta) providing evidence for disturbances in resting state brain activity being specific to genetic liability for schizophrenia. Schizophrenia patients exhibited augmented low-frequency EEG activity (delta, theta), while bipolar disorder patients and the 2 groups of relatives generally failed to manifest similar low-frequency EEG abnormalities. The Val(158)Met polymorphism for the catechol-O-methyl transferase (COMT) gene was most strongly associated with delta and theta activity in schizophrenia patients. Met homozygote schizophrenia patients exhibited augmented activity for the 2 low-frequency bands compared with control subjects. Excessive high-frequency EEG activity over frontal brain regions may serve as an endophenotype that reflects cortical expression of genetic vulnerability for schizophrenia. Low-frequency resting state EEG anomalies in schizophrenia may relate to disorder-specific pathophysiology in schizophrenia and the influence of the COMT gene on tonic dopamanergic function.
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Affiliation(s)
| | | | - Scott R. Sponheim
- Department of Psychology, University of Minnesota, Twin Cities,Department of Psychiatry, University of Minnesota,Veterans Affairs Medical Center, Minneapolis, MN,To whom correspondence should be addressed; 116B, VA Medical Center, Once Veterans Drive, Minneapolis, MN 55417; tel: 612-725-2074, fax: 612-727-5964, e-mail:
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