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Hanekamp S, Simonyan K. The large-scale structural connectome of task-specific focal dystonia. Hum Brain Mapp 2020; 41:3253-3265. [PMID: 32311207 PMCID: PMC7375103 DOI: 10.1002/hbm.25012] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/27/2020] [Accepted: 04/06/2020] [Indexed: 12/19/2022] Open
Abstract
The emerging view of dystonia is that of a large‐scale functional network disorder, in which the communication is disrupted between sensorimotor cortical areas, basal ganglia, thalamus, and cerebellum. The structural underpinnings of functional alterations in dystonia are, however, poorly understood. Notably, it is unclear whether structural changes form a larger‐scale dystonic network or rather remain focal to isolated brain regions, merely underlying their functional abnormalities. Using diffusion‐weighted imaging and graph theoretical analysis, we examined inter‐regional white matter connectivity of the whole‐brain structural network in two different forms of task‐specific focal dystonia, writer's cramp and laryngeal dystonia, compared to healthy individuals. We show that, in addition to profoundly altered functional network in focal dystonia, its structural connectome is characterized by large‐scale aberrations due to abnormal transfer of prefrontal and parietal nodes between neural communities and the reorganization of normal hub architecture, commonly involving the insula and superior frontal gyrus in patients compared to controls. Other prominent common changes involved the basal ganglia, parietal and cingulate cortical regions, whereas premotor and occipital abnormalities distinctly characterized the two forms of dystonia. We propose a revised pathophysiological model of focal dystonia as a disorder of both functional and structural connectomes, where dystonia form‐specific abnormalities underlie the divergent mechanisms in the development of distinct clinical symptomatology. These findings may guide the development of novel therapeutic strategies directed at targeted neuromodulation of pathophysiological brain regions for the restoration of their structural and functional connectivity.
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Affiliation(s)
- Sandra Hanekamp
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Kristina Simonyan
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA.,Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
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Veronese M, Moro L, Arcolin M, Dipasquale O, Rizzo G, Expert P, Khan W, Fisher PM, Svarer C, Bertoldo A, Howes O, Turkheimer FE. Covariance statistics and network analysis of brain PET imaging studies. Sci Rep 2019; 9:2496. [PMID: 30792460 PMCID: PMC6385265 DOI: 10.1038/s41598-019-39005-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 01/09/2019] [Indexed: 02/06/2023] Open
Abstract
The analysis of structural and functional neuroimaging data using graph theory has increasingly become a popular approach for visualising and understanding anatomical and functional relationships between different cerebral areas. In this work we applied a network-based approach for brain PET studies using population-based covariance matrices, with the aim to explore topological tracer kinetic differences in cross-sectional investigations. Simulations, test-retest studies and applications to cross-sectional datasets from three different tracers ([18F]FDG, [18F]FDOPA and [11C]SB217045) and more than 400 PET scans were investigated to assess the applicability of the methodology in healthy controls and patients. A validation of statistics, including the assessment of false positive differences in parametric versus permutation testing, was also performed. Results showed good reproducibility and general applicability of the method within the range of experimental settings typical of PET neuroimaging studies, with permutation being the method of choice for the statistical analysis. The use of graph theory for the quantification of [18F]FDG brain PET covariance, including the definition of an entropy metric, proved to be particularly relevant for Alzheimer's disease, showing an association with the progression of the pathology. This study shows that covariance statistics can be applied to PET neuroimaging data to investigate the topological characteristics of the tracer kinetics and its related targets, although sensitivity to experimental variables, group inhomogeneities and image resolution need to be considered when the method is applied to cross-sectional studies.
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Affiliation(s)
- Mattia Veronese
- Department of Neuroimaging, IoPPN, King's College London, London, United Kingdom.
| | - Lucia Moro
- Department of Neuroimaging, IoPPN, King's College London, London, United Kingdom
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Marco Arcolin
- Department of Neuroimaging, IoPPN, King's College London, London, United Kingdom
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Ottavia Dipasquale
- Department of Neuroimaging, IoPPN, King's College London, London, United Kingdom
| | | | - Paul Expert
- Department of Neuroimaging, IoPPN, King's College London, London, United Kingdom
- Department of Mathematics, Imperial College London, London, United Kingdom
- EPSRC Centre for Mathematics of Precision Healthcare, Imperial College London, London, United Kingdom
| | - Wasim Khan
- Department of Neuroimaging, IoPPN, King's College London, London, United Kingdom
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, Melbourne, Australia
| | - Patrick M Fisher
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Claus Svarer
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | | | - Oliver Howes
- Department of Psychosis studies, IoPPN, King's College London, London, United Kingdom
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Shen J, Kassir MA, Wu J, Zhang Q, Zhou S, Xuan SY, Li Q, Ye Y, Hu J. MR volumetric study of piriform-cortical amygdala and orbitofrontal cortices: the aging effect. PLoS One 2013; 8:e74526. [PMID: 24069317 PMCID: PMC3771930 DOI: 10.1371/journal.pone.0074526] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Accepted: 08/02/2013] [Indexed: 11/24/2022] Open
Abstract
Introduction The piriform cortex and cortical amygdala (PCA) and the orbitofrontal cortex (OFC) are considered olfactory-related brain regions. This study aims to elucidate the normal volumes of PCA and OFC of each age groups (20.0-70.0 year old), and whether the volumes of PCA and OFC decline with increasing age and diminishing olfactory function. Methods One hundred and eleven healthy right-handed participants (54 males, 57 females), age 20.0 to 70.0 years were recruited to join this study after excluding all the major causes of olfactory dysfunction. Volumetric measurements of PCA and OFC were performed using consecutive 1-mm thick coronal slices of high-resolution 3-D MRIs. A validated olfactory function test (Sniffin’ Sticks) assessed olfactory function, which measured odor threshold (THD), odor discrimination (DIS), and odor identification (ID) as well as their sum score (TDI). Results The volume of OFC decreased with age and significantly correlated with age-related declines in olfactory function. The volume of OFC showed significant age-group differences, particularly after 40 years old (p < 0.001), while olfactory function decreased significantly after 60 years old (p < 0.001). Similar age-related volumetric changes were not found for PCA (p = 0.772). Additionally, there was significant correlation between OFC and DIS on the Right Side (p = 0.028) and between OFC and TDI on both sides (p < 0.05). There was no similar correlation for PCA. Conclusions Aging can have a great impact on the volume of OFC and olfactory function while it has much smaller effect on the volume of PCA. The result could be useful to establish normal volumes of PCA and OFC of each age group to assess neurological disorders that affect olfactory function.
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Affiliation(s)
- Jing Shen
- Department of Radiology, Affiliated Zhongshan Hospital of Dalian University, Dalian, China
| | - Mohammad A. Kassir
- Department of Radiology, Wayne State University, Detroit, Michigan, United States of America
| | - Jianlin Wu
- Department of Radiology, Affiliated Zhongshan Hospital of Dalian University, Dalian, China
- * E-mail:
| | - Qing Zhang
- Department of Radiology, Affiliated Zhongshan Hospital of Dalian University, Dalian, China
| | - Shiyu Zhou
- Department of Mental Health, Dalian medical University, Dalian, China
| | - Stephanie Y. Xuan
- University of Toronto, Faculty of Arts & Science, Toronto, Ontario, Canada
| | - Qinghang Li
- Department of Neurological Surgery, Wayne State University, Detroit, Michigan, United States of America
| | - Yongquan Ye
- Department of Radiology, Wayne State University, Detroit, Michigan, United States of America
| | - Jiani Hu
- Department of Radiology, Wayne State University, Detroit, Michigan, United States of America
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Chang L, Lee PL, Yiannoutsos CT, Ernst T, Marra CM, Richards T, Kolson D, Schifitto G, Jarvik JG, Miller EN, Lenkinski R, Gonzalez G, Navia BA. A multicenter in vivo proton-MRS study of HIV-associated dementia and its relationship to age. Neuroimage 2005; 23:1336-47. [PMID: 15589098 DOI: 10.1016/j.neuroimage.2004.07.067] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2004] [Revised: 07/17/2004] [Accepted: 07/29/2004] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVE Differences in diagnostic criteria and methods have led to mixed results regarding the metabolite pattern of HIV-associated brain injury in relation to neurocognitive impairment. Therefore, a multicenter MRS consortium was formed to evaluate the neurometabolites in HIV patients with or without cognitive impairment. METHODS Proton magnetic resonance spectroscopy (MRS) at short-echo time (30 ms) was assessed in the frontal white matter, basal ganglia, and parietal cortex of 100 HIV patients [61 with AIDS dementia complex (ADC) and 39 neuroasymptomatic (NAS)] and 37 seronegative (SN) controls. RESULTS Compared to SN, NAS had higher glial marker myoinositol-to-creatine ratio (MI/Cr) in the white matter (multivariate analyses, adjusted P=0.001), while ADC showed further increased MI/Cr in the white matter and basal ganglia (both P<0.001), and increased choline compounds (Cho)/Cr in white matter (P=0.04) and basal ganglia (P<0.001). Compared to NAS, ADC showed a reduction in the neuronal marker N-acetyl compound (NA)/Cr in the frontal white matter (P=0.007). CSF, but not plasma, viral load correlated with MI/Cr and Cho/Cr in white matter and NAA/Cr in parietal cortex. HIV infection and aging had additive effects on Cho/Cr and MI/Cr in the basal ganglia and white matter. CONCLUSIONS The results suggest that glial activation occurs during the NAS stages of HIV infection, whereas further inflammatory activity in the basal ganglia and neuronal injury in the white matter is associated with the development of cognitive impairment. Aging may further exacerbate brain metabolites associated with inflammation in HIV patient and thereby increase the risk for cognitive impairment.
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Affiliation(s)
- L Chang
- Department of Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI 96813, USA
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Videbech P, Ravnkilde B, Pedersen TH, Hartvig H, Egander A, Clemmensen K, Rasmussen NA, Andersen F, Gjedde A, Rosenberg R. The Danish PET/depression project: clinical symptoms and cerebral blood flow. A regions-of-interest analysis. Acta Psychiatr Scand 2002; 106:35-44. [PMID: 12100346 DOI: 10.1034/j.1600-0447.2002.02245.x] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE We wanted to explore associations between clinical symptoms of depression and the blood flow to specific regions of the brain. Furthermore, we wanted to compare the regions-of-interest (ROI) method with the functions-of-interest (FOI) approach. METHOD The resting blood flow to 42 ROI in the brain was obtained with positron emission tomography (PET) imaging in 42 representative in-patients with major depression and 47 matched healthy controls. RESULTS The patients had increased blood flow to hippocampus, cerebellum, anterior cingulate gyrus, and the basal ganglia. A strong negative correlation was found between the degree of psychomotor retardation of the patients and the blood flow to the dorsolateral and supraorbital prefrontal cortices. The total Hamilton score was correlated with the blood flow to the hippocampus. CONCLUSION Our findings support the notion that depressed patients have disturbances in the loops connecting the frontal lobes, limbic system, basal ganglia, and cerebellum.
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Affiliation(s)
- P Videbech
- Institute for Basic Psychiatric Research, Department of Biological Psychiatry, Psychiatric Hospital, Aarhus University Hospitals, Risskov, Denmark.
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Feise RJ. Do multiple outcome measures require p-value adjustment? BMC Med Res Methodol 2002; 2:8. [PMID: 12069695 PMCID: PMC117123 DOI: 10.1186/1471-2288-2-8] [Citation(s) in RCA: 851] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2002] [Accepted: 06/17/2002] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Readers may question the interpretation of findings in clinical trials when multiple outcome measures are used without adjustment of the p-value. This question arises because of the increased risk of Type I errors (findings of false "significance") when multiple simultaneous hypotheses are tested at set p-values. The primary aim of this study was to estimate the need to make appropriate p-value adjustments in clinical trials to compensate for a possible increased risk in committing Type I errors when multiple outcome measures are used. DISCUSSION The classicists believe that the chance of finding at least one test statistically significant due to chance and incorrectly declaring a difference increases as the number of comparisons increases. The rationalists have the following objections to that theory: 1) P-value adjustments are calculated based on how many tests are to be considered, and that number has been defined arbitrarily and variably; 2) P-value adjustments reduce the chance of making type I errors, but they increase the chance of making type II errors or needing to increase the sample size. SUMMARY Readers should balance a study's statistical significance with the magnitude of effect, the quality of the study and with findings from other studies. Researchers facing multiple outcome measures might want to either select a primary outcome measure or use a global assessment measure, rather than adjusting the p-value.
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Affiliation(s)
- Ronald J Feise
- Institute of Evidence-Based Chiropractic 6252 Rookery Road, Fort Collins, Colorado 80528, USA.
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