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Ozelo HFB, Alessio A, Sercheli MS, Bilevicius E, Pedro T, Pereira FRS, Rondina JM, Damasceno BP, Cendes F, Covolan RJM. Pattern changes of EEG oscillations and BOLD signals associated with temporal lobe epilepsy as revealed by a working memory task. BMC Neurosci 2014; 15:52. [PMID: 24766708 PMCID: PMC4021216 DOI: 10.1186/1471-2202-15-52] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 04/14/2014] [Indexed: 11/13/2022] Open
Abstract
Background It is known that the abnormal neural activity in epilepsy may be associated to the reorganization of neural circuits and brain plasticity in various ways. On that basis, we hypothesized that changes in neuronal circuitry due to epilepsy could lead to measurable variations in patterns of both EEG and BOLD signals in patients performing some cognitive task as compared to what would be obtained in normal condition. Thus, the aim of this study was to compare the cerebral areas involved in EEG oscillations versus fMRI signal patterns during a working memory (WM) task in normal controls and patients with refractory mesial temporal lobe epilepsy (MTLE) associated with hippocampal sclerosis (HS). The study included six patients with left MTLE-HS (left-HS group) and seven normal controls (control group) matched to the patients by age and educational level, both groups undergoing a blocked design paradigm based on Sternberg test during separated EEG and fMRI sessions. This test consisted of encoding and maintenance of a variable number of consonant letters on WM. Results EEG analysis for the encoding period revealed the presence of theta and alpha oscillations in the frontal and parietal areas, respectively. Likewise, fMRI showed the co-occurrence of positive and negative BOLD signals in both brain regions. As for the maintenance period, whereas EEG analysis revealed disappearance of theta oscillation, fMRI showed decrease of positive BOLD in frontal area and increase of negative BOLD in the posterior part of the brain. Conclusions Generally speaking, these patterns of electrophysiological and hemodynamic signals were observed for both control and left-HS groups. However, the data also revealed remarkable differences between these groups that are consistent with the hypothesis of reorganization of brain circuitry associated with epilepsy.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Roberto J M Covolan
- Neurophysics Group, Gleb Wataghin Physics Institute, University of Campinas, Unicamp, Campinas, Brazil.
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Balthazar MLF, Pereira FRS, Lopes TM, da Silva EL, Coan AC, Campos BM, Duncan NW, Stella F, Northoff G, Damasceno BP, Cendes F. Neuropsychiatric symptoms in Alzheimer's disease are related to functional connectivity alterations in the salience network. Hum Brain Mapp 2013; 35:1237-46. [PMID: 23418130 DOI: 10.1002/hbm.22248] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 11/06/2012] [Accepted: 12/03/2012] [Indexed: 11/12/2022] Open
Abstract
Neuropsychiatric syndromes are highly prevalent in Alzheimer's disease (AD), but their neurobiology is not completely understood. New methods in functional magnetic resonance imaging, such as intrinsic functional connectivity or "resting-state" analysis, may help to clarify this issue. Using such approaches, alterations in the default-mode and salience networks (SNs) have been described in Alzheimer's, although their relationship with specific symptoms remains unclear. We therefore carried out resting-state functional connectivity analysis with 20 patients with mild to moderate AD, and correlated their scores on neuropsychiatric inventory syndromes (apathy, hyperactivity, affective syndrome, and psychosis) with maps of connectivity in the default mode network and SN. In addition, we compared network connectivity in these patients with that in 17 healthy elderly control subjects. All analyses were controlled for gray matter density and other potential confounds. Alzheimer's patients showed increased functional connectivity within the SN compared with controls (right anterior cingulate cortex and left medial frontal gyrus), along with reduced functional connectivity in the default-mode network (bilateral precuneus). A correlation between increased connectivity in anterior cingulate cortex and right insula areas of the SN and hyperactivity syndrome (agitation, irritability, aberrant motor behavior, euphoria, and disinhibition) was found. These findings demonstrate an association between specific network changes in AD and particular neuropsychiatric symptom types. This underlines the potential clinical significance of resting state alterations in future diagnosis and therapy.
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Affiliation(s)
- Marcio L F Balthazar
- Neuroimaging Laboratory, Department of Neurology, Medical Sciences School, University of Campinas (UNICAMP), Brazil
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Bezerra DM, Pereira FRS, Cendes F, Jackowski MP, Nakano EY, Moscoso MAA, Ribeiz SRI, Avila R, Castro CCD, Bottino CMC. DTI voxelwise analysis did not differentiate older depressed patients from older subjects without depression. J Psychiatr Res 2012; 46:1643-9. [PMID: 23040088 DOI: 10.1016/j.jpsychires.2012.09.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 08/19/2012] [Accepted: 09/01/2012] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Neuroimaging has been widely used in studies to investigate depression in the elderly because it is a noninvasive technique, and it allows the detection of structural and functional brain alterations. Fractional anisotropy (FA) and mean diffusivity (MD) are neuroimaging indexes of the microstructural integrity of white matter, which are measured using diffusion tensor imaging (DTI). The aim of this study was to investigate differences in FA or MD in the entire brain without a previously determined region of interest (ROI) between depressed and non-depressed elderly patients. METHOD Brain magnetic resonance imaging scans were obtained from 47 depressed elderly patients, diagnosed according to DSM-IV criteria, and 36 healthy elderly patients as controls. Voxelwise statistical analysis of FA data was performed using tract-based spatial statistics (TBSS). RESULTS After controlling for age, no significant differences among FA and MD parameters were observed in the depressed elderly patients. No significant correlations were found between cognitive performance and FA or MD parameters. CONCLUSION There were no significant differences among FA or MD values between mildly or moderately depressed and non-depressed elderly patients when the brain was analyzed without a previously determined ROI.
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Affiliation(s)
- Diana Moitinho Bezerra
- Old Age Research Group - PROTER, Institute and Department of Psychiatry, University of São Paulo, São Paulo, Brazil.
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França MC, Yasuda CL, Pereira FRS, D'Abreu A, Lopes-Ramos CM, Rosa MV, Cendes F, Lopes-Cendes I. White and grey matter abnormalities in patients with SPG11 mutations. J Neurol Neurosurg Psychiatry 2012; 83:828-33. [PMID: 22696581 DOI: 10.1136/jnnp-2011-300129] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Mutations in SPG11 are the most frequent known cause of autosomal recessive hereditary spastic paraplegia. Corpus callosum thinning is a hallmark of the condition but little is known about damage to other structures in the CNS. OBJECTIVE To evaluate in vivo cerebral damage in patients with SPG11 mutations. METHODS 5 patients and 15 age and sex matched healthy controls underwent high resolution diffusion tensor imaging (32 directions) and a T1 volumetric (1 mm slices) acquisition protocol in a 3 T scanner (Philips Achieva). These sequences were then analysed through voxel based morphometry (VBM) and tract based spatial statistics (TBSS). RESULTS Mean age of the patients was 23.6±4.5 years (range 14-45) and mean duration of disease was 12 years (range 5-15). All patients presented with progressive spastic paraplegia and three were already wheelchair bound when first evaluated. Mutations found were: c.529_533delATATT, c.704_705delAT, c.733_734delAT, c.118C>T and c.7256A>G. VBM identified significant grey matter atrophy in both the thalamus and lentiform nuclei. TBSS analyses revealed reduced fractional anisotropy involving symmetrically subcortical white matter of the temporal and frontal lobes, the cingulated gyrus, cuneus, striatum, corpus callosum and brainstem. CONCLUSIONS Widespread white matter damage in patients with SPG11 mutations has been demonstrated. Grey matter atrophy was prominent in both the thalamus and basal ganglia but not in the cerebral cortex. These findings suggest that neuronal damage/dysfunction is more widespread than previously recognised in this condition.
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Affiliation(s)
- Marcondes C França
- Department of Neurology and Neuroimaging Laboratory, Faculty of Medicine, University of Campinase UNICAMP, Campinas, São Paulo, Brazil
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Balthazar MLF, Yasuda CL, Lopes TM, Pereira FRS, Damasceno BP, Cendes F. Neural correlates of lexical-semantic memory: A voxel-based morphometry study in mild AD, aMCI and normal aging. Dement Neuropsychol 2011; 5:69-77. [PMID: 29213726 PMCID: PMC5619300 DOI: 10.1590/s1980-57642011dn05020003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neuroanatomical correlations of naming and lexical-semantic memory are not yet
fully understood. The most influential approaches share the view that semantic
representations reflect the manner in which information has been acquired
through perception and action, and that each brain area processes different
modalities of semantic representations. Despite these anatomical differences in
semantic processing, generalization across different features that have similar
semantic significance is one of the main characteristics of human cognition.
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Affiliation(s)
- Marcio L F Balthazar
- Laboratory of Neuroimaging, Department of Neurology, Medical School, University of Campinas (UNICAMP), Campinas SP, Brazil
| | - Clarissa L Yasuda
- Laboratory of Neuroimaging, Department of Neurology, Medical School, University of Campinas (UNICAMP), Campinas SP, Brazil
| | - Tátila M Lopes
- Laboratory of Neuroimaging, Department of Neurology, Medical School, University of Campinas (UNICAMP), Campinas SP, Brazil
| | - Fabrício R S Pereira
- Laboratory of Neuroimaging, Department of Neurology, Medical School, University of Campinas (UNICAMP), Campinas SP, Brazil
| | - Benito Pereira Damasceno
- Laboratory of Neuroimaging, Department of Neurology, Medical School, University of Campinas (UNICAMP), Campinas SP, Brazil
| | - Fernando Cendes
- Laboratory of Neuroimaging, Department of Neurology, Medical School, University of Campinas (UNICAMP), Campinas SP, Brazil
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Pereira FRS, Alessio A, Sercheli MS, Pedro T, Bilevicius E, Rondina JM, Ozelo HFB, Castellano G, Covolan RJM, Damasceno BP, Cendes F. Asymmetrical hippocampal connectivity in mesial temporal lobe epilepsy: evidence from resting state fMRI. BMC Neurosci 2010; 11:66. [PMID: 20525202 PMCID: PMC2890013 DOI: 10.1186/1471-2202-11-66] [Citation(s) in RCA: 161] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Accepted: 06/02/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mesial temporal lobe epilepsy (MTLE), the most common type of focal epilepsy in adults, is often caused by hippocampal sclerosis (HS). Patients with HS usually present memory dysfunction, which is material-specific according to the hemisphere involved and has been correlated to the degree of HS as measured by postoperative histopathology as well as by the degree of hippocampal atrophy on magnetic resonance imaging (MRI). Verbal memory is mostly affected by left-sided HS, whereas visuo-spatial memory is more affected by right HS. Some of these impairments may be related to abnormalities of the network in which individual hippocampus takes part. Functional connectivity can play an important role to understand how the hippocampi interact with other brain areas. It can be estimated via functional Magnetic Resonance Imaging (fMRI) resting state experiments by evaluating patterns of functional networks. In this study, we investigated the functional connectivity patterns of 9 control subjects, 9 patients with right MTLE and 9 patients with left MTLE. RESULTS We detected differences in functional connectivity within and between hippocampi in patients with unilateral MTLE associated with ipsilateral HS by resting state fMRI. Functional connectivity resulted to be more impaired ipsilateral to the seizure focus in both patient groups when compared to control subjects. This effect was even more pronounced for the left MTLE group. CONCLUSIONS The findings presented here suggest that left HS causes more reduction of functional connectivity than right HS in subjects with left hemisphere dominance for language.
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Affiliation(s)
- Fabrício R S Pereira
- Neuroimaging Laboratory, Department of Neurology, University of Campinas - UNICAMP, Cidade Universitária, Campinas, SP, Brazil
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Sercheli MS, Bilevicius E, Alessio A, Ozelo H, Pereira FRS, Rondina JM, Cendes F, Covolan RJM. EEG spike source localization before and after surgery for temporal lobe epilepsy: a BOLD EEG-fMRI and independent component analysis study. Braz J Med Biol Res 2010; 42:582-7. [PMID: 19448910 DOI: 10.1590/s0100-879x2009000600017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2008] [Accepted: 04/07/2009] [Indexed: 11/21/2022] Open
Abstract
Simultaneous measurements of EEG-functional magnetic resonance imaging (fMRI) combine the high temporal resolution of EEG with the distinctive spatial resolution of fMRI. The purpose of this EEG-fMRI study was to search for hemodynamic responses (blood oxygen level-dependent--BOLD responses) associated with interictal activity in a case of right mesial temporal lobe epilepsy before and after a successful selective amygdalohippocampectomy. Therefore, the study found the epileptogenic source by this noninvasive imaging technique and compared the results after removing the atrophied hippocampus. Additionally, the present study investigated the effectiveness of two different ways of localizing epileptiform spike sources, i.e., BOLD contrast and independent component analysis dipole model, by comparing their respective outcomes to the resected epileptogenic region. Our findings suggested a right hippocampus induction of the large interictal activity in the left hemisphere. Although almost a quarter of the dipoles were found near the right hippocampus region, dipole modeling resulted in a widespread distribution, making EEG analysis too weak to precisely determine by itself the source localization even by a sophisticated method of analysis such as independent component analysis. On the other hand, the combined EEG-fMRI technique made it possible to highlight the epileptogenic foci quite efficiently.
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Affiliation(s)
- M S Sercheli
- Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, SP, Brasil.
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Sercheli MS, Bilevicius E, Ozelo H, Alessio A, Pereira FRS, Rondina JM, Pedro T, Cendes F, Covolan RJM. Spatial distribution of BOLD responses in mesial temporal lobe epilepsy: an EEG-fMRI study. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)72221-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Pereira FRS, Alessio A, Rondina JM, Pedro T, Sercheli MS, Ozelo HFB, Bilevicius E, Zibetti MVW, Castellano G, Covolan RJM, Damasceno BP, Cendes F. Effective connectivity of unilateral left or right mesial temporal lobe epilepsy during verbal memory task. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)70727-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Siqueira SF, Dias SMG, Hardouin P, Pereira FRS, Lejeune B, de Souza AP. Transcription of succinate dehydrogenase subunit 4 (sdh4) gene in potato: detection of extensive RNA editing and co-transcription with cytochrome oxidase subunit III (cox3) gene. Curr Genet 2002; 41:282-9. [PMID: 12172970 DOI: 10.1007/s00294-002-0294-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2001] [Accepted: 04/05/2002] [Indexed: 11/25/2022]
Abstract
The potato (Solanum tuberosum L.) mitochondrial cox3/ sdh4 gene cluster was previously identified by heterologous hybridization using a Marchantia polymorpha sdh4 probe. In this work, this potato gene cluster was cloned, sequenced and its expression was evaluated. The gene sequence and gene locus organization were found to be similar to the corresponding gene cluster in other dicot species, where known. Northern hybridizations with potato and cauliflower (Brassica oleraceae) mtRNA and RT-PCR analyses using potato mtRNA indicated that cox3 and sdh4 are co-transcribed in both species, generating a complex transcription pattern, where several transcripts from 1.1 kb to 4.4 kb are found. The potato transcript from this cluster displayed 14 and 13 RNA-editing sites, in the cox3 and sdh4 genes respectively, which changed the codon identity to amino acids and created a sdh4 partially edited stop codon. Forty-three cDNA clones were analyzed for editing process and revealed different partial-editing with no apparent sequential processing in the sdh4 gene.
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Affiliation(s)
- Susely F Siqueira
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Cidade Universitária Zeferino Vaz, 13083-970, C.P. 6010, Campinas, São Paulo, Brazil
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