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Ibáñez-Molina A, Crespo Cobo Y, Soriano Peña MF, Iglesias-Parro S, Ruiz de Miras J. Mutual information of multiple rhythms in schizophrenia. Brain Struct Funct 2024; 229:285-295. [PMID: 38091050 PMCID: PMC10917874 DOI: 10.1007/s00429-023-02744-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 11/28/2023] [Indexed: 03/07/2024]
Abstract
Interactions between different cortical rhythms, such as slow and fast oscillations, have been hypothesized to underlie many cognitive functions. In patients diagnosed with schizophrenia, there is some evidence indicating that the interplay between slow and fast oscillations might be impaired or disrupted. In this study, we investigated multiple oscillatory interactions in schizophrenia using a novel approach based on information theory. This method allowed us to investigate interactions from a new perspective, where two or more rhythm interactions could be analyzed at the same time. We calculated the mutual information of multiple rhythms (MIMR) for EEG segments registered in resting state. Following previous studies, we focused on rhythm interactions between theta, alpha, and gamma. The results showed that, in general, MIMR was higher in patients than in controls for alpha-gamma and theta-gamma couplings. This finding of an increased coupling between slow and fast rhythms in schizophrenia may indicate complex interactions in the Default Mode Network (DMN) related to hyperactivation of internally guided cognition.
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Affiliation(s)
| | - Yasmina Crespo Cobo
- Department of Psychology, University of Jaén, Jaén, Spain.
- Department of Psychology, St. Agustín University Hospital, Av. San Cristóbal, 2D, 23700, Linares, Jaén, Spain.
| | - Maria Felipa Soriano Peña
- Department of Psychology, St. Agustín University Hospital, Av. San Cristóbal, 2D, 23700, Linares, Jaén, Spain
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2
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Obukhov A, Krasnyanskiy M, Volkov A, Nazarova A, Teselkin D, Patutin K, Zajceva D. Method for Assessing the Influence of Phobic Stimuli in Virtual Simulators. J Imaging 2023; 9:195. [PMID: 37888302 PMCID: PMC10607658 DOI: 10.3390/jimaging9100195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/17/2023] [Accepted: 09/22/2023] [Indexed: 10/28/2023] Open
Abstract
In the organizing of professional training, the assessment of the trainee's reaction and state in stressful situations is of great importance. Phobic reactions are a specific type of stress reaction that, however, is rarely taken into account when developing virtual simulators, and are a risk factor in the workplace. A method for evaluating the impact of various phobic stimuli on the quality of training is considered, which takes into account the time, accuracy, and speed of performing professional tasks, as well as the characteristics of electroencephalograms (the amplitude, power, coherence, Hurst exponent, and degree of interhemispheric asymmetry). To evaluate the impact of phobias during experimental research, participants in the experimental group performed exercises in different environments: under normal conditions and under the influence of acrophobic and arachnophobic stimuli. The participants were divided into subgroups using clustering algorithms and an expert neurologist. After that, a comparison of the subgroup metrics was carried out. The research conducted makes it possible to partially confirm our hypotheses about the negative impact of phobic effects on some participants in the experimental group. The relationship between the reaction to a phobia and the characteristics of brain activity was revealed, and the characteristics of the electroencephalogram signal were considered as the metrics for detecting a phobic reaction.
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Affiliation(s)
- Artem Obukhov
- The Laboratory of Medical VR Simulator Systems for Training, Diagnostics and Rehabilitation, Tambov State Technical University, Tambov 392000, Russia; (M.K.); (A.V.); (A.N.); (D.T.); (K.P.); (D.Z.)
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3
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Prieto-Alcántara M, Ibáñez-Molina A, Crespo-Cobo Y, Molina R, Soriano MF, Iglesias-Parro S. Alpha and gamma EEG coherence during on-task and mind wandering states in schizophrenia. Clin Neurophysiol 2023; 146:21-29. [PMID: 36495599 DOI: 10.1016/j.clinph.2022.11.010] [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: 06/15/2022] [Revised: 10/12/2022] [Accepted: 11/13/2022] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Electroencephalographic (EEG) coherence is one of the most relevant physiological measures used to detect abnormalities in patients with schizophrenia. The present study applies a task-related EEG coherence approach to understand cognitive processing in patients with schizophrenia and healthy controls. METHODS EEG coherence for alpha and gamma frequency bands was analyzed in a group of patients with schizophrenia and a group of healthy controls during the performance of an ecological task of sustained attention. We compared EEG coherence when participants presented externally directed cognitive states (On-Task) and when they presented cognitive distraction episodes (Mind-Wandering). RESULTS Results reflect cortical differences between groups (higher coherence for schizophrenia in the frontocentral and fronto-temporal regions, and higher coherence for healthy-controls in the postero-central regions), especially in the On-Task condition for the alpha band, compared to Mind-Wandering episodes. Few individual differences in gamma coherence were found. CONCLUSIONS The current study provides evidence of neurophysiological differences underlying different cognitive states in schizophrenia and healthy controls. SIGNIFICANCE Differences between groups may reflect inhibitory processes necessary for the successful processing of information, especially in the alpha band, given its role in cortical inhibition processes. Patients may activate compensatory inhibitory mechanisms when performing the task, reflected in increased coherence in fronto-temporal regions.
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Affiliation(s)
| | | | | | - Rosa Molina
- Psychology Department, University of Jaén, 23071 Jaén, Spain
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4
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Korda A, Ventouras E, Asvestas P, Toumaian M, Matsopoulos G, Smyrnis N. Convolutional neural network propagation on electroencephalographic scalograms for detection of schizophrenia. Clin Neurophysiol 2022; 139:90-105. [DOI: 10.1016/j.clinph.2022.04.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 02/11/2022] [Accepted: 04/01/2022] [Indexed: 11/28/2022]
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5
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Dimitriadis SI. Reconfiguration of αmplitude driven dominant coupling modes (DoCM) mediated by α-band in adolescents with schizophrenia spectrum disorders. Prog Neuropsychopharmacol Biol Psychiatry 2021; 108:110073. [PMID: 32805332 DOI: 10.1016/j.pnpbp.2020.110073] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 08/10/2020] [Accepted: 08/10/2020] [Indexed: 12/16/2022]
Abstract
Electroencephalography (EEG) based biomarkers have been shown to correlate with the presence of psychotic disorders. Increased delta and decreased alpha power in psychosis indicate an abnormal arousal state. We investigated brain activity across the basic EEG frequencies and also dynamic functional connectivity of both intra and cross-frequency coupling that could reveal a neurophysiological biomarker linked to an aberrant modulating role of alpha frequency in adolescents with schizophrenia spectrum disorders (SSDs). A dynamic functional connectivity graph (DFCG) has been estimated using the imaginary part of phase lag value (iPLV) and correlation of the envelope (corrEnv). We analyzed DFCG profiles of electroencephalographic resting state (eyes closed) recordings of healthy controls (HC) (n = 39) and SSDs subjects (n = 45) in basic frequency bands {δ,θ,α1,α2,β1,β2,γ}. In our analysis, we incorporated both intra and cross-frequency coupling modes. Adopting our recent Dominant Coupling Mode (DοCM) model leads to the construction of an integrated DFCG (iDFCG) that encapsulates the functional strength and the DοCM of every pair of brain areas. We revealed significantly higher ratios of delta/alpha1,2 power spectrum in SSDs subjects versus HC. The probability distribution (PD) of amplitude driven DoCM mediated by alpha frequency differentiated SSDs from HC with absolute accuracy (100%). The network Flexibility Index (FI) was significantly lower for subjects with SSDs compared to the HC group. Our analysis supports the central role of alpha frequency alterations in the neurophysiological mechanisms of SSDs. Currents findings open up new diagnostic pathways to clinical detection of SSDs and support the design of rational neurofeedback training.
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Affiliation(s)
- Stavros I Dimitriadis
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, College of Biomedical and Life Sciences, Cardiff University, Cardiff, United Kingdom; Neuroinformatics Group, Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, College of Biomedical and Life Sciences, Cardiff University, Cardiff, United Kingdom; Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, College of Biomedical and Life Sciences, Cardiff University, Cardiff, United Kingdom; School of Psychology, College of Biomedical and Life Sciences,Cardiff University, Cardiff, United Kingdom; Neuroscience and Mental Health Research Institute, School of Medicine, College of Biomedical and Life Sciences,Cardiff University, Cardiff, United Kingdom; MRC Centre for Neuropsychiatric Genetics and Genomics, School of Medicine, College of Biomedical and Life Sciences, Cardiff University, Cardiff, United Kingdom.
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6
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Hederih J, Nuninga JO, van Eijk K, van Dellen E, Smit DJA, Oranje B, Luykx JJ. Genetic underpinnings of schizophrenia-related electroencephalographical intermediate phenotypes: A systematic review and meta-analysis. Prog Neuropsychopharmacol Biol Psychiatry 2021; 104:110001. [PMID: 32525059 DOI: 10.1016/j.pnpbp.2020.110001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/02/2020] [Accepted: 06/03/2020] [Indexed: 02/04/2023]
Abstract
Although substantial research into genetics of psychotic disorders has been conducted, a large proportion of their genetic architecture has remained unresolved. Electroencephalographical intermediate phenotypes (EIP) have the potential to constitute a valuable tool when studying genetic risk loci for schizophrenia, in particular P3b amplitude, P50 suppression, mismatch negativity (MMN) and resting state power spectra of the electroencephalogram (EEG). Here, we systematically reviewed studies investigating the association of single nucleotide polymorphisms (SNPs) with these EIPs and meta-analysed them when appropriate. We retrieved 45 studies (N = 34,971 study participants). Four SNPs investigated in more than one study were genome-wide significant for an association with schizophrenia and three were genome-wide suggestive, based on a lookup in the influential 2014 GWAS (Ripke et al., 2014). However, in our meta-analyses, rs1625579 failed to reach a statistically significant association with p3b amplitude decrease and rs4680 risk allele carrier status was not associated with p3b amplitude decrease or with impaired p50 suppression. In conclusion, evidence for SNP associations with EIPs remains limited to individual studies. Careful selection of EIPs and SNPs, combined with consistent reporting of effect sizes, directions of effect and p-values would aid future meta-analyses.
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Affiliation(s)
- Jure Hederih
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, CX 3584, the Netherlands; Medical Sciences Division, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom.
| | - Jasper O Nuninga
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, CX 3584, the Netherlands
| | - Kristel van Eijk
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, CX 3584, the Netherlands
| | - Edwin van Dellen
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, CX 3584, the Netherlands; Melbourne Neuropsychiatry Centre, Department of Psychiatry, University of Melbourne and Melbourne Health, Melbourne, Australia
| | - Dirk J A Smit
- Department of Psychiatry, Academic Medical Centre, Meibergdreef 5, Amsterdam 1105 AZ, the Netherlands
| | - Bob Oranje
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, CX 3584, the Netherlands
| | - Jurjen J Luykx
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, CX 3584, the Netherlands; Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, CX 3584, the Netherlands; GGNet Mental Health, Apeldoorn, the Netherlands
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7
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Resting-state electroencephalographic delta rhythms may reflect global cortical arousal in healthy old seniors and patients with Alzheimer's disease dementia. Int J Psychophysiol 2020; 158:259-270. [DOI: 10.1016/j.ijpsycho.2020.08.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 08/25/2020] [Accepted: 08/27/2020] [Indexed: 12/23/2022]
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8
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Babiloni C, Noce G, Di Bonaventura C, Lizio R, Pascarelli MT, Tucci F, Soricelli A, Ferri R, Nobili F, Famà F, Palma E, Cifelli P, Marizzoni M, Stocchi F, Frisoni GB, Del Percio C. Abnormalities of Cortical Sources of Resting State Delta Electroencephalographic Rhythms Are Related to Epileptiform Activity in Patients With Amnesic Mild Cognitive Impairment Not Due to Alzheimer's Disease. Front Neurol 2020; 11:514136. [PMID: 33192962 PMCID: PMC7644902 DOI: 10.3389/fneur.2020.514136] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 09/14/2020] [Indexed: 11/13/2022] Open
Abstract
In the present exploratory and retrospective study, we hypothesized that cortical sources of resting state eyes-closed electroencephalographic (rsEEG) rhythms might be more abnormal in patients with epileptiform EEG activity (spike-sharp wave discharges, giant spikes) and amnesic mild cognitive impairment not due to Alzheimer's disease (noADMCI-EEA) than matched noADMCI patients without EEA (noADMCI-noEEA). Clinical, neuroimaging, neuropsychological, and rsEEG data in 32 noADMCI and 30 normal elderly (Nold) subjects were available in a national archive. Age, gender, and education were carefully matched among them. No subject had received a clinical diagnosis of epilepsy. Individual alpha frequency peak (IAF) was used to determine the delta, theta, and alpha frequency bands of rsEEG rhythms. Fixed beta and gamma bands were also considered. Regional rsEEG cortical sources were estimated by eLORETA freeware. Area under receiver operating characteristic (AUROC) curves indexed the accuracy of eLORETA solutions in the classification between noADMCI-EEA and noADMCI-noEEA individuals. As novel findings, EEA was observed in 41% of noADMCI patients. Furthermore, these noADMCI-EEA patients showed higher temporal delta source activities as compared to noADMCI-no EEA patients and Nold subjects. Those activities discriminated individuals of the two NoADMCI groups with an accuracy of about 70%. The significant percentage of noADMCI-EEA patients showing EEA and marked abnormalities in temporal rsEEG rhythms at delta frequencies suggest a substantial role of underlying neural hypersynchronization mechanisms in their brain dysfunctions.
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Affiliation(s)
- Claudio Babiloni
- Department of Physiology and Pharmacology "Vittorio Erspamer", Sapienza University of Rome, Rome, Italy.,San Raffaele Cassino, Cassino (FR), Italy
| | | | - Carlo Di Bonaventura
- Epilepsy Unit, Department of Neurosciences/Mental Health, Sapienza University of Rome, Rome, Italy
| | | | | | - Federico Tucci
- Department of Physiology and Pharmacology "Vittorio Erspamer", Sapienza University of Rome, Rome, Italy
| | - Andrea Soricelli
- IRCCS SDN, Naples, Italy.,Department of Motor Sciences and Healthiness, University of Naples Parthenope, Naples, Italy
| | | | - Flavio Nobili
- Clinica Neurologica, IRCCS Ospedale Policlinico San Martino, Genova, Italy.,Dipartimento di Neuroscienze, Oftalmologia, Genetica, Riabilitazione e Scienze Materno-infantili (DiNOGMI), Università di Genova, Genova, Italy
| | - Francesco Famà
- Dipartimento di Neuroscienze, Oftalmologia, Genetica, Riabilitazione e Scienze Materno-infantili (DiNOGMI), Università di Genova, Genova, Italy
| | - Eleonora Palma
- Department of Physiology and Pharmacology "Vittorio Erspamer", Sapienza University of Rome, Rome, Italy.,Pasteur Institute-Cenci Bolognetti Foundation, Rome, Italy
| | - Pierangelo Cifelli
- IRCCS Neuromed, Pozzilli, Italy.,Scienze Cliniche Applicate e Biotecnologiche, University of L'Aquila, L'Aquila, Italy
| | - Moira Marizzoni
- Laboratory of Alzheimer's Neuroimaging and Epidemiology, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | | | - Giovanni B Frisoni
- Laboratory of Alzheimer's Neuroimaging and Epidemiology, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.,Memory Clinic and LANVIE-Laboratory of Neuroimaging of Aging, University Hospitals and University of Geneva, Geneva, Switzerland
| | - Claudio Del Percio
- Department of Physiology and Pharmacology "Vittorio Erspamer", Sapienza University of Rome, Rome, Italy
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9
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A multimodal magnetoencephalography 7 T fMRI and 7 T proton MR spectroscopy study in first episode psychosis. NPJ SCHIZOPHRENIA 2020; 6:23. [PMID: 32887887 PMCID: PMC7473853 DOI: 10.1038/s41537-020-00113-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Accepted: 07/23/2020] [Indexed: 11/08/2022]
Abstract
We combined magnetoencephalography (MEG), 7 T proton magnetic resonance spectroscopy (MRS), and 7 T fMRI during performance of a task in a group of 23 first episode psychosis (FEP) patients and 26 matched healthy controls (HC). We recorded both the auditory evoked response to 40 Hz tone clicks and the resting state in MEG. Neurometabolite levels were obtained from the anterior cingulate cortex (ACC). The fMRI BOLD response was obtained during the Stroop inhibitory control task. FEP showed a significant increase in resting state low frequency theta activity (p < 0.05; Cohen d = 0.69), but no significant difference in the 40 Hz auditory evoked response compared to HC. An across-groups whole brain analysis of the fMRI BOLD response identified eight regions that were significantly activated during task performance (p < 0.01, FDR-corrected); the mean signal extracted from those regions was significantly different between the groups (p = 0.0006; d = 1.19). In the combined FEP and HC group, there was a significant correlation between the BOLD signal during task performance and MEG resting state low frequency activity (p < 0.05). In FEP, we report significant alteration in resting state low frequency MEG activity, but no alterations in auditory evoked gamma band response, suggesting that the former is a more robust biomarker of early psychosis. There were no correlations between gamma oscillations and GABA levels in either HC or FEP. Finally, in this study, each of the three imaging modalities differentiated FEP from HC; fMRI with good and MEG and MRS with moderate effect size.
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10
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The relationship between resting electroencephalogram oscillatory abnormalities and schizotypal personality traits in the first-degree relatives of schizophrenia patients. Neuroreport 2020; 30:1215-1221. [PMID: 31634240 DOI: 10.1097/wnr.0000000000001350] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Although a large amount of studies have manifested resting state electroencephalogram oscillatory abnormalities in schizophrenia and their first-degree relatives and in schizotype, the results are far from consistent and no research found any relationship between electroencephalograph (EEG) abnormalities and schizotypal personality in first-degree relatives. The present study is to verify the modifications of EEG power spectra in eyes-open resting state of schizophrenia and first-degree relatives, and to investigate associations between EEG band power and schizotypal personality traits in first-degree relatives of schizophrenia patients. Participant samples in this study consisted of 33 healthy normal controls, 35 unaffected first-degree relatives of schizophrenia patients and 35 schizophrenia patients. Group differences in resting EEG band power were examined via repeated-measures analysis of variance, and correlation between EEG power and schizotypal personality traits via Pearson Correlation analysis. The results showed that patients with schizophrenia exhibited increased delta, theta and alpha activity over anterior and central regions in eyes-open resting state compared with that of normal control. Gamma band power was found for the first time to be negatively correlated to schizotypal personality traits in first-degree relatives of schizophrenia patients. To conclusion, these findings suggested that low-frequency EEG activity might be neural manifestations of pathophysiological changes in the brain of schizophrenia, and gamma band activity might be an approach to measure the genetic liability of the disorder.
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11
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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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12
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Hu DK, Li LY, Lopour BA, Martin EA. Schizotypy dimensions are associated with altered resting state alpha connectivity. Int J Psychophysiol 2020; 155:175-183. [PMID: 32599002 DOI: 10.1016/j.ijpsycho.2020.06.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/27/2020] [Accepted: 06/22/2020] [Indexed: 11/16/2022]
Abstract
The disconnection hypothesis of schizophrenia says that symptoms are explained by dysfunctional connections across a wide range of brain networks. Despite some support for this hypothesis, there have been mixed findings. One reason for these may be the multidimensional nature of schizophrenia symptoms. In order to clarify the relationship between symptoms and brain networks, the current study included individuals at risk for schizophrenia-spectrum disorders who either report extreme levels of positive schizotypy traits (perceptual aberrations and magical ideation, or "PerMag"; n = 23), or an extreme negative schizotypy trait (social anhedonia, or "SocAnh"; n = 19), as well as a control group (n = 18). Resting-state alpha electroencephalography was collected, and functional networks for each subject were measured using the phase-lag index to calculate the connectivity between channel pairs based on the symmetry of instantaneous phase differences over time. Furthermore, graph theory measures were introduced to identify network features exclusive to schizotypy groups. We found that the PerMag group exhibited a smaller difference in node strength and clustering coefficient in frontal/occipital and central/occipital regional comparisons compared to controls, suggesting a more widespread network. The SocAnh group exhibited a larger difference in degree in the central/occipital regional comparison relative to controls, suggesting a localized occipital focus in the connectivity network. Regional differences in functional connectivity suggest that different schizotypy dimensions are manifested at the network level by different forms of disconnections. Taken together, these findings lend further support to the disconnection hypothesis and suggest that altered connectivity networks may serve as a potential biomarker for schizophrenia risk.
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Affiliation(s)
- Derek K Hu
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, USA
| | - Lilian Y Li
- Department of Psychological Science, University of California, Irvine, Irvine, CA, USA
| | - Beth A Lopour
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, USA
| | - Elizabeth A Martin
- Department of Psychological Science, University of California, Irvine, Irvine, CA, USA.
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13
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Phang CR, Noman F, Hussain H, Ting CM, Ombao H. A Multi-Domain Connectome Convolutional Neural Network for Identifying Schizophrenia From EEG Connectivity Patterns. IEEE J Biomed Health Inform 2020; 24:1333-1343. [DOI: 10.1109/jbhi.2019.2941222] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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14
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Guo S, He N, Liu Z, Linli Z, Tao H, Palaniyappan L. Brain-Wide Functional Dysconnectivity in Schizophrenia: Parsing Diathesis, Resilience, and the Effects of Clinical Expression. CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 2020; 65:21-29. [PMID: 31775531 PMCID: PMC6966251 DOI: 10.1177/0706743719890174] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND The functional dysconnectivity observed from functional magnetic resonance imaging (fMRI) studies in schizophrenia is also seen in unaffected siblings indicating its association with the genetic diathesis. We intended to apportion resting-state dysconnectivity into components that represent genetic diathesis, clinical expression or treatment effect, and resilience. METHODS fMRI data were acquired from 28 schizophrenia patients, 28 unaffected siblings, and 60 healthy controls. Based on Dosenbach's atlas, we extracted time series of 160 regions of interest. After constructing functional network, we investigated between-group differences in strength and diversity of functional connectivity and topological properties of undirected graphs. RESULTS Using analysis of variance, we found 88 dysconnectivities. Post hoc t tests revealed that 62.5% were associated with genetic diathesis and 21.6% were associated with clinical expression. Topologically, we observed increased degree, clustering coefficient, and global efficiency in the sibling group compared to both patients and controls. CONCLUSION A large portion of the resting-state functional dysconnectivity seen in patients represents a genetic diathesis effect. The most prominent network-level disruption is the dysconnectivity among nodes of the default mode and salience networks. Despite their predisposition, unaffected siblings show a pattern of resilience in the emergent connectomic topology. Our findings could potentially help refine imaging genetics approaches currently used in the pursuit of the pathophysiology of schizophrenia.
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Affiliation(s)
- Shuixia Guo
- MOE-LCSM, School of Mathematics and Statistics, Hunan Normal University, Changsha, People's Republic of China.,Key Laboratory of Molecular Epidemiology of Hunan Province, School of Medicine, Hunan Normal University, Changsha, People's Republic of China
| | - Ningning He
- MOE-LCSM, School of Mathematics and Statistics, Hunan Normal University, Changsha, People's Republic of China
| | - Zhening Liu
- Institute of Mental Health, Second Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Zeqiang Linli
- MOE-LCSM, School of Mathematics and Statistics, Hunan Normal University, Changsha, People's Republic of China
| | - Haojuan Tao
- Institute of Mental Health, Second Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Lena Palaniyappan
- Department of Psychiatry, University of Western Ontario, London, Ontario, Canada.,Robarts Research Institute, University of Western Ontario, London, Ontario, Canada.,Lawson Health Research Institute, London, Ontario, Canada
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15
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International Federation of Clinical Neurophysiology (IFCN) – EEG research workgroup: Recommendations on frequency and topographic analysis of resting state EEG rhythms. Part 1: Applications in clinical research studies. Clin Neurophysiol 2020; 131:285-307. [DOI: 10.1016/j.clinph.2019.06.234] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 05/17/2019] [Accepted: 06/02/2019] [Indexed: 01/22/2023]
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16
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Vignapiano A, Koenig T, Mucci A, Giordano GM, Amodio A, Altamura M, Bellomo A, Brugnoli R, Corrivetti G, Di Lorenzo G, Girardi P, Monteleone P, Niolu C, Galderisi S, Maj M. Disorganization and cognitive impairment in schizophrenia: New insights from electrophysiological findings. Int J Psychophysiol 2019; 145:99-108. [DOI: 10.1016/j.ijpsycho.2019.03.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 03/06/2019] [Accepted: 03/15/2019] [Indexed: 12/18/2022]
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17
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Zaytseva Y, Garakh Z, Novototsky-Vlasov V, Gurovich IY, Shmukler A, Papaefstathiou A, Horáček J, Španiel F, Strelets VB. EEG coherence in a mental arithmetic task performance in first episode schizophrenia and schizoaffective disorder. Clin Neurophysiol 2018; 129:2315-2324. [DOI: 10.1016/j.clinph.2018.08.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 08/24/2018] [Accepted: 08/31/2018] [Indexed: 02/07/2023]
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18
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Reilly TJ, Nottage JF, Studerus E, Rutigliano G, Micheli AID, Fusar-Poli P, McGuire P. Gamma band oscillations in the early phase of psychosis: A systematic review. Neurosci Biobehav Rev 2018; 90:381-399. [PMID: 29656029 DOI: 10.1016/j.neubiorev.2018.04.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 02/20/2018] [Accepted: 04/09/2018] [Indexed: 12/28/2022]
Abstract
Abnormal gamma oscillations, measured by electroencephalography (EEG), have been associated with chronic psychotic disorders, but their prevalence in the early phase of psychosis is less clear. We sought to address this by systematically reviewing the relevant literature. We searched for EEG studies of gamma band oscillations in subjects at high risk for psychosis and in patients with first episode psychosis. The following measures of gamma oscillations were extracted: resting power, evoked power, induced power, connectivity and peak frequency. Forty-five studies with a total of 3099 participants were included. There were potential sources of bias in the study designs and potential artefacts. Although there were few consistent findings, several studies reported decreased evoked or induced power in both high risk subjects and first episode patients. Studies using larger samples with serial EEG measurements, and designs that minimise artefacts that occur at the gamma frequency may advance work in this area.
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Affiliation(s)
- Thomas J Reilly
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, 16 De Crespigny Park, London, SE5 8AF, UK.
| | - Judith F Nottage
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, 16 De Crespigny Park, London, SE5 8AF, UK
| | - Erich Studerus
- Center for Gender Research and Early Detection, University of Basel Psychiatric Clinics, Basel, Switzerland
| | - Grazia Rutigliano
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, 16 De Crespigny Park, London, SE5 8AF, UK; Department of Clinical and Experimental Medicine, University of Pisa, Italy
| | - Andrea I De Micheli
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, 16 De Crespigny Park, London, SE5 8AF, UK; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Paolo Fusar-Poli
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, 16 De Crespigny Park, London, SE5 8AF, UK
| | - Philip McGuire
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, 16 De Crespigny Park, London, SE5 8AF, UK
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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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20
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Kotsan IY, Kozachuk NO, Kuznetsov IP, Poruchynskii AI. Indices of Coherence of EEG Rhythms in the Course of Cognitive Activity as Markers of Creative Thinking: Gender Specificity. NEUROPHYSIOLOGY+ 2016. [DOI: 10.1007/s11062-016-9600-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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21
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Maran M, Grent-‘t-Jong T, Uhlhaas PJ. Electrophysiological insights into connectivity anomalies in schizophrenia: a systematic review. ACTA ACUST UNITED AC 2016. [DOI: 10.1186/s40810-016-0020-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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22
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Reconstruction of EEG from limited channel acquisition using estimated signal correlation. Biomed Signal Process Control 2016. [DOI: 10.1016/j.bspc.2016.02.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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23
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Andreou C, Nolte G, Leicht G, Polomac N, Hanganu-Opatz IL, Lambert M, Engel AK, Mulert C. Increased Resting-State Gamma-Band Connectivity in First-Episode Schizophrenia. Schizophr Bull 2015; 41:930-9. [PMID: 25170031 PMCID: PMC4466170 DOI: 10.1093/schbul/sbu121] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Schizophrenia has long been suggested to represent a disorder with prominent neural dysconnectivity. Gamma-band oscillations are highly relevant in this context, due both to their proposed involvement in neuronal synchronization and to their association with neurotransmitter systems relevant for schizophrenia. Several task-related studies have confirmed reduced power and synchronization of gamma-band oscillations in schizophrenia, but it has been suggested that these findings might not apply to the resting state. The present study aimed to investigate resting-state gamma-band connectivity in patients with schizophrenia. METHODS Sixty-four channel resting-state electroencephalography (eyes closed) was recorded in 22 patients with first-episode schizophrenia and 22 healthy controls matched for age and gender. Orthogonalized power envelope correlation was used as a measure of connectivity across 80 cortical regions at 40 Hz. Mean connectivity at each region was compared across groups using the nonparametric randomization approach. Additionally, the network-based statistic was applied to identify affected networks in patients. RESULTS Patients displayed increased mean functional gamma-band connectivity compared to controls in the left rolandic operculum. Network-based analyses indicated increased connectivity in patients within a strongly lateralized network consisting mainly of left inferior frontal/orbitofrontal, lateral and medial temporal, and inferior parietal areas. Within this network, gamma-band connectivity was higher in patients with low positive and disorganization symptom levels. CONCLUSIONS The present study provides a link between resting-state gamma-band connectivity and the core symptoms of schizophrenia. The observed findings are different than those reported by task-related studies, suggesting that resting-state studies might reveal new aspects in the pathophysiology of schizophrenia.
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Affiliation(s)
- Christina Andreou
- Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany;
| | - Guido Nolte
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Gregor Leicht
- Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nenad Polomac
- Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ileana L. Hanganu-Opatz
- Developmental Neurophysiology, Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Martin Lambert
- Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Andreas K. Engel
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph Mulert
- Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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24
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Li HJ, Xu Y, Zhang KR, Hoptman MJ, Zuo XN. Homotopic connectivity in drug-naïve, first-episode, early-onset schizophrenia. J Child Psychol Psychiatry 2015; 56:432-43. [PMID: 25130214 PMCID: PMC4333112 DOI: 10.1111/jcpp.12307] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/10/2014] [Indexed: 12/21/2022]
Abstract
BACKGROUND The disconnection hypothesis of schizophrenia has been extensively tested in adults. Recent studies have reported the presence of brain disconnection in younger patients, adding evidence to support the neurodevelopmental hypothesis of schizophrenia. Because of drug confounds in chronic and medicated patients, it has been extremely challenging for researchers to directly investigate abnormalities in the development of connectivity and their role in the pathophysiology of schizophrenia. The present study aimed to examine functional homotopy - a measure of interhemispheric connection - and its relevance to clinical symptoms in first-episode drug-naïve early-onset schizophrenia (EOS) patients. METHODS Resting-state functional magnetic resonance imaging was performed in 26 first-episode drug-naïve EOS patients (age: 14.5 ± 1.94, 13 males) and 25 matched typically developing controls (TDCs) (age: 14.4 ± 2.97, 13 males). We were mainly concerned with the functional connectivity between any pair of symmetric interhemispheric voxels (i.e., functional homotopy) measured by voxel-mirrored homotopic connectivity (VMHC). RESULTS Early-onset schizophrenia patients exhibited both global and regional VMHC reductions in comparison with TDCs. Reduced VMHC values were observed within the superior temporal cortex and postcentral gyrus. These interhemispheric synchronization deficits were negatively correlated with negative symptom of the Positive and Negative Syndrome Scale. Moreover, regions of interest analyses based on left and right clusters of temporal cortex and postcentral gyrus revealed abnormal heterotopic connectivity in EOS patients. CONCLUSIONS Our findings provide novel neurodevelopmental evidence for the disconnection hypothesis of schizophrenia and suggest that these alterations occur early in the course of the disease and are independent of medication status.
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Affiliation(s)
- Hui-Jie Li
- Key Laboratory of Behavioral Science and Magnetic Resonance Imaging Research Center, Chinese Academy of Sciences, Beijing, China,Laboratory for Functional Connectome and Development, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Yong Xu
- Department of Psychiatry, First Hospital of Shanxi Medical University, Taiyuan, China
| | - Ke-Rang Zhang
- Department of Psychiatry, First Hospital of Shanxi Medical University, Taiyuan, China
| | - Matthew J. Hoptman
- Department of Psychiatry, New York University School of Medicine, New York, USA,Schizophrenia Research Division, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, USA
| | - Xi-Nian Zuo
- Key Laboratory of Behavioral Science and Magnetic Resonance Imaging Research Center, Chinese Academy of Sciences, Beijing, China,Laboratory for Functional Connectome and Development, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
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25
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Soh P, Narayanan B, Khadka S, Calhoun VD, Keshavan MS, Tamminga CA, Sweeney JA, Clementz BA, Pearlson GD. Joint Coupling of Awake EEG Frequency Activity and MRI Gray Matter Volumes in the Psychosis Dimension: A BSNIP Study. Front Psychiatry 2015; 6:162. [PMID: 26617533 PMCID: PMC4637406 DOI: 10.3389/fpsyt.2015.00162] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 10/26/2015] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Many studies have examined either electroencephalogram (EEG) frequency activity or gray matter volumes (GMV) in various psychoses [including schizophrenia (SZ), schizoaffective (SZA), and psychotic bipolar disorder (PBP)]. Prior work demonstrated similar EEG and gray matter abnormalities in both SZ and PBP. Integrating EEG and GMV and jointly analyzing the combined data fully elucidates the linkage between the two and may provide better biomarker- or endophenotype-specificity for a particular illness. Joint exploratory investigations of EEG and GMV are scarce in the literature and the relationship between the two in psychosis is even less explored. We investigated a joint multivariate model to test whether the linear relationship or linkage between awake EEG (AEEG) frequency activity and GMV is abnormal across the psychosis dimension and if such effects are also present in first-degree relatives. METHODS We assessed 607 subjects comprising 264 probands [105 SZ, 72 SZA, and 87 PBP], 233 of their first degree relatives [82 SZ relatives (SZR), 71 SZA relatives (SZAR), and 80 PBP relatives (PBPR)], and 110 healthy comparison subjects (HC). All subjects underwent structural MRI (sMRI) and EEG scans. Frequency activity and voxel-based morphometric GMV were derived from EEG and sMRI data, respectively. Seven AEEG frequency and gray matter components were extracted using Joint independent component analysis (jICA). The loading coefficients (LC) were examined for group differences using analysis of covariance. Further, the LCs were correlated with psychopathology scores to identify relationship with clinical symptoms. RESULTS Joint ICA revealed a single component differentiating SZ from HC (p < 0.006), comprising increased posterior alpha activity associated with decreased volume in inferior parietal lobe, supramarginal, parahippocampal gyrus, middle frontal, inferior temporal gyri, and increased volume of uncus and culmen. No components were aberrant in either PBP or SZA or any relative group. No significant association was identified with clinical symptom measures. CONCLUSION Our data suggest that a joint EEG and GMV model yielded a biomarker specific to SZ, not abnormal in PBP or SZA. Alpha activity was related to both increased and decreased volume in different cortical structures. Additionally, the joint model failed to identify endophenotypes across psychotic disorders.
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Affiliation(s)
- Pauline Soh
- Olin Neuropsychiatry Research Center, Institute of Living , Hartford, CT , USA
| | - Balaji Narayanan
- Olin Neuropsychiatry Research Center, Institute of Living , Hartford, CT , USA
| | - Sabin Khadka
- Olin Neuropsychiatry Research Center, Institute of Living , Hartford, CT , USA
| | - Vince D Calhoun
- Department of Electrical and Computer Engineering, University of New Mexico , Albuquerque, NM , USA ; The Mind Research Network , Albuquerque, NM , USA ; Department of Psychiatry, Yale University School of Medicine , New Haven, CT , USA
| | - Matcheri S Keshavan
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School , Boston, MA , USA
| | - Carol A Tamminga
- Department of Psychiatry, University of Texas Southwestern Medical Center , Dallas, TX , USA
| | - John A Sweeney
- Department of Psychiatry, University of Texas Southwestern Medical Center , Dallas, TX , USA
| | - Brett A Clementz
- Department of Psychology, University of Georgia , Athens, GA , USA
| | - Godfrey D Pearlson
- Olin Neuropsychiatry Research Center, Institute of Living , Hartford, CT , USA ; Department of Psychiatry, Yale University School of Medicine , New Haven, CT , USA ; Department of Neurobiology, Yale University School of Medicine , New Haven, CT , USA
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26
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Ventouras EC, Margariti A, Chondraki P, Kalatzis I, Economou NT, Tsekou H, Paparrigopoulos T, Ktonas P. EEG-based investigation of brain connectivity changes in psychotic patients undergoing the primitive expression form of dance therapy: a methodological pilot study. Cogn Neurodyn 2014; 9:231-48. [PMID: 25852781 DOI: 10.1007/s11571-014-9319-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Revised: 10/22/2014] [Accepted: 11/05/2014] [Indexed: 11/27/2022] Open
Abstract
Primitive expression (PE) is a form of dance therapy (DT) that involves an interaction of ethologically and socially based forms which are supplied for re-enactment. There exist very few studies of DT applications including in their protocol the measurement of neurophysiological parameters. The present pilot study investigates the use of the correlation coefficient (ρ) and mutual information (MI), and of novel measures extracted from ρ and MI, on electroencephalographic (EEG) data recorded in patients with schizophrenia while they undergo PE DT, in order to expand the set of neurophysiology-based approaches for quantifying possible DT effects, using parameters that might provide insights about any potential brain connectivity changes in these patients during the PE DT process. Indication is provided for an acute potentiation effect, apparent at late-stage PE DT, on the inter-hemispheric connectivity in frontal areas, as well as for attenuation of the inter-hemispheric connectivity of left frontal and right central areas and for potentiation of the intra-hemispheric connectivity of frontal and central areas, bilaterally, in the transition from early to late-stage PE DT. This pilot study indicates that by using EEG connectivity measures based on ρ and MI, the set of useful neurophysiology-based approaches for quantifying possible DT effects is expanded. In the framework of the present study, the causes of the observed connectivity changes cannot be attributed with certainty to PE DT, but indications are provided that these measures may contribute to a detailed assessment of neurophysiological mechanisms possibly being affected by this therapeutic process.
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Affiliation(s)
- Errikos-Chaim Ventouras
- Department of Biomedical Engineering, Technological Educational Institution of Athens, Agiou Spyridonos Str., Egaleo, Athens, 12210 Greece
| | - Alexia Margariti
- 1st Psychiatric Clinic, Department of Psychiatry, Medical School, Eginition Hospital, University of Athens, 74 Vas. Sophias Ave., Athens, 11528 Greece ; Department of Theater Studies, University of Peloponnese, 21, Vas. Konstantinou Str., Nafplion, 21460 Greece
| | - Paraskevi Chondraki
- 1st Psychiatric Clinic, Department of Psychiatry, Medical School, Eginition Hospital, University of Athens, 74 Vas. Sophias Ave., Athens, 11528 Greece
| | - Ioannis Kalatzis
- Department of Biomedical Engineering, Technological Educational Institution of Athens, Agiou Spyridonos Str., Egaleo, Athens, 12210 Greece
| | - Nicholas-Tiberio Economou
- 1st Psychiatric Clinic, Department of Psychiatry, Medical School, Eginition Hospital, University of Athens, 74 Vas. Sophias Ave., Athens, 11528 Greece
| | - Hara Tsekou
- 1st Psychiatric Clinic, Department of Psychiatry, Medical School, Eginition Hospital, University of Athens, 74 Vas. Sophias Ave., Athens, 11528 Greece
| | - Thomas Paparrigopoulos
- 1st Psychiatric Clinic, Department of Psychiatry, Medical School, Eginition Hospital, University of Athens, 74 Vas. Sophias Ave., Athens, 11528 Greece
| | - Periklis Ktonas
- 1st Psychiatric Clinic, Department of Psychiatry, Medical School, Eginition Hospital, University of Athens, 74 Vas. Sophias Ave., Athens, 11528 Greece
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27
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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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28
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Lehmann D, Faber PL, Pascual-Marqui RD, Milz P, Herrmann WM, Koukkou M, Saito N, Winterer G, Kochi K. Functionally aberrant electrophysiological cortical connectivities in first episode medication-naive schizophrenics from three psychiatry centers. Front Hum Neurosci 2014; 8:635. [PMID: 25191252 PMCID: PMC4138932 DOI: 10.3389/fnhum.2014.00635] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 07/30/2014] [Indexed: 01/08/2023] Open
Abstract
Functional dissociation between brain processes is widely hypothesized to account for aberrations of thought and emotions in schizophrenic patients. The typically small groups of analyzed schizophrenic patients yielded different neurophysiological findings, probably because small patient groups are likely to comprise different schizophrenia subtypes. We analyzed multichannel eyes-closed resting EEG from three small groups of acutely ill, first episode productive schizophrenic patients before start of medication (from three centers: Bern N = 9; Osaka N = 9; Berlin N = 12) and their controls. Low resolution brain electromagnetic tomography (LORETA) was used to compute intracortical source model-based lagged functional connectivity not biased by volume conduction effects between 19 cortical regions of interest (ROIs). The connectivities were compared between controls and patients of each group. Conjunction analysis determined six aberrant cortical functional connectivities that were the same in the three patient groups. Four of these six concerned the facilitating EEG alpha-1 frequency activity; they were decreased in the patients. Another two of these six connectivities concerned the inhibiting EEG delta frequency activity; they were increased in the patients. The principal orientation of the six aberrant cortical functional connectivities was sagittal; five of them involved both hemispheres. In sum, activity in the posterior brain areas of preprocessing functions and the anterior brain areas of evaluation and behavior control functions were compromised by either decreased coupled activation or increased coupled inhibition, common across schizophrenia subtypes in the three patient groups. These results of the analyzed three independent groups of schizophrenics support the concept of functional dissociation.
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Affiliation(s)
- Dietrich Lehmann
- Department of Psychiatry, Psychotherapy and Psychosomatics, The KEY Institute for Brain-Mind Research, University Hospital for Psychiatry Zurich, Switzerland
| | - Pascal L Faber
- Department of Psychiatry, Psychotherapy and Psychosomatics, The KEY Institute for Brain-Mind Research, University Hospital for Psychiatry Zurich, Switzerland
| | - Roberto D Pascual-Marqui
- Department of Psychiatry, Psychotherapy and Psychosomatics, The KEY Institute for Brain-Mind Research, University Hospital for Psychiatry Zurich, Switzerland
| | - Patricia Milz
- Department of Psychiatry, Psychotherapy and Psychosomatics, The KEY Institute for Brain-Mind Research, University Hospital for Psychiatry Zurich, Switzerland
| | - Werner M Herrmann
- Laboratory of Clinical Psychophysiology, Department of Psychiatry, University Hospital Benjamin Franklin, Free University of Berlin Berlin, Germany
| | - Martha Koukkou
- Department of Psychiatry, Psychotherapy and Psychosomatics, The KEY Institute for Brain-Mind Research, University Hospital for Psychiatry Zurich, Switzerland
| | | | - Georg Winterer
- Experimental and Clinical Research Center, Charité - University Medicine Berlin Berlin, Germany
| | - Kieko Kochi
- Department of Psychiatry, Psychotherapy and Psychosomatics, The KEY Institute for Brain-Mind Research, University Hospital for Psychiatry Zurich, Switzerland
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29
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Fern RF, Matute C, Stys PK. White matter injury: Ischemic and nonischemic. Glia 2014; 62:1780-9. [PMID: 25043122 DOI: 10.1002/glia.22722] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 06/18/2014] [Accepted: 06/30/2014] [Indexed: 02/02/2023]
Abstract
Ischemic pathologies of white matter (WM) include a large proportion of stroke and developmental lesions while multiple sclerosis (MS) is the archetype nonischemic pathology. Growing evidence suggests other important diseases including neurodegenerative and psychiatric disorders also involve a significant WM component. Axonal, oligodendroglial, and astroglial damage proceed via distinct mechanisms in ischemic WM and these mechanisms evolve dramatically with maturation. Axons may pass through four developmental stages where the pattern of membrane protein expression influences how the structure responds to ischemia; WM astrocytes pass through at least two and differ significantly in their ischemia tolerance from grey matter astrocytes; oligodendroglia pass through at least three, with the highly ischemia intolerant pre-oligodendrocyte (pre-Oli) stage linking the less sensitive precursor and mature phenotypes. Neurotransmitters play a central role in WM pathology at all ages. Glutamate excitotoxicity in WM has both necrotic and apoptotic components; the latter mediated by intracellular pathways which differ between receptor types. ATP excitotoxicity may be largely mediated by the P2X7 receptor and also has both necrotic and apoptotic components. Interplay between microglia and other cell types is a critical element in the injury process. A growing appreciation of the significance of WM injury for nonischemic neurological disorders is currently stimulating research into mechanisms; with curious similarities being found with those operating during ischemia. A good example is traumatic brain injury, where axonal pathology can proceed via almost identical pathways to those described during acute ischemia.
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Affiliation(s)
- Robert F Fern
- Peninsula School of Medicine and Dentistry, University of Plymouth, United Kingdom
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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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Dickerson DD, Bilkey DK. Aberrant neural synchrony in the maternal immune activation model: using translatable measures to explore targeted interventions. Front Behav Neurosci 2013; 7:217. [PMID: 24409130 PMCID: PMC3873515 DOI: 10.3389/fnbeh.2013.00217] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 12/16/2013] [Indexed: 01/01/2023] Open
Abstract
Maternal exposure to infection occurring mid-gestation produces a three-fold increase in the risk of schizophrenia in the offspring. The critical initiating factor appears to be the maternal immune activation (MIA) that follows infection. This process can be induced in rodents by exposure of pregnant dams to the viral mimic Poly I:C, which triggers an immune response that results in structural, functional, behavioral, and electrophysiological phenotypes in the adult offspring that model those seen in schizophrenia. We used this model to explore the role of synchronization in brain neural networks, a process thought to be dysfunctional in schizophrenia and previously associated with positive, negative, and cognitive symptoms of schizophrenia. Exposure of pregnant dams to Poly I:C on GD15 produced an impairment in long-range neural synchrony in adult offspring between two regions implicated in schizophrenia pathology; the hippocampus and the medial prefrontal cortex (mPFC). This reduction in synchrony was ameliorated by acute doses of the antipsychotic clozapine. MIA animals have previously been shown to have impaired pre-pulse inhibition (PPI), a gold-standard measure of schizophrenia-like deficits in animal models. Our data showed that deficits in synchrony were positively correlated with the impairments in PPI. Subsequent analysis of LFP activity during the PPI response also showed that reduced coupling between the mPFC and the hippocampus following processing of the pre-pulse was associated with reduced PPI. The ability of the MIA intervention to model neurodevelopmental aspects of schizophrenia pathology provides a useful platform from which to investigate the ontogeny of aberrant synchronous processes. Further, the way in which the model expresses translatable deficits such as aberrant synchrony and reduced PPI will allow researchers to explore novel intervention strategies targeted to these changes.
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Affiliation(s)
| | - David K Bilkey
- Department of Psychology, University of Otago Dunedin, New Zealand
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Interhemispheric EEG coherence is reduced in auditory cortical regions in schizophrenia patients with auditory hallucinations. Int J Psychophysiol 2013; 89:63-71. [PMID: 23707337 DOI: 10.1016/j.ijpsycho.2013.05.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 02/13/2013] [Accepted: 05/10/2013] [Indexed: 11/24/2022]
Abstract
Central auditory processing has been reported to be impaired in schizophrenia patients who experience auditory hallucinations, and interhemispheric transfer in auditory circuits may be compromised. In this study, we used EEG spectral coherence to examine interhemispheric connectivity between cortical areas known to be important in the processing of auditory information. Coherence was compared across three subject groups: schizophrenia patients with a recent history of auditory hallucinations (AH), schizophrenia patients who did not experience auditory hallucinations (nonAH), and healthy controls (HC). Subjects listened to pure tone and word stimuli while EEG was recorded continuously. Upper alpha and upper beta band coherence was calculated from six pairs of electrodes located over homologous auditory areas in the left and right cerebral hemispheres. Significant between-group differences were found on four electrode pairs (C3-C4, C5-C6, Ft7-Ft8 and Cp5-Cp6) in the upper alpha band. Relative to both the HC and nonAH groups, coherence was lower in the AH patients, consistent with the hypothesis that interhemispheric connectivity is reduced in these patients.
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Hasan A, Misewitsch K, Nitsche MA, Gruber O, Padberg F, Falkai P, Wobrock T. Impaired motor cortex responses in non-psychotic first-degree relatives of schizophrenia patients: a cathodal tDCS pilot study. Brain Stimul 2013; 6:821-9. [PMID: 23545473 DOI: 10.1016/j.brs.2013.03.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 01/09/2013] [Accepted: 03/03/2013] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Schizophrenia has recently been described as a disorder of impaired plasticity and dysconnectivity. Several lines of evidence suggest that alterations in glutamatergic neurotransmission underlie different symptom domains of schizophrenia. Little is known about the impact of genetic liability on cortical plasticity and connectivity in schizophrenia. OBJECTIVE To compare N-methyl-d-aspartate receptor (NMDAR)-dependent cortical plasticity and connectivity in schizophrenia patients and unaffected first-degree relatives to that in healthy subjects. METHODS Cortical plasticity can be induced in the motor cortex with cathodal transcranial direct current stimulation (tDCS). Animal and human research indicates that this long-term depression-like plasticity (LTD-like) is NMDAR dependent, and that these plasticity shifts can last for several hours. tDCS-induced plasticity was assessed by measuring motor-evoked potentials (MEPs) generated by applying transcranial magnetic stimulation (TMS) to both hemispheres in healthy controls, chronically ill schizophrenia patients and unaffected first-degree relatives. RESULTS Compared to healthy controls, both first-degree relatives and schizophrenia patients showed abolished motor-cortical LTD-like plasticity of the stimulated hemisphere. On the non-stimulated hemisphere, plasticity was again abolished in schizophrenia patients, whereas first-degree relatives had a reversed plasticity. CONCLUSIONS Non-psychotic and clinically unaffected first-degree relatives showed an alteration and a reversal of LTD-like cortical plasticity, indicating functional alterations of glutamatergic transmission as a result of a genetic liability for developing schizophrenia. These results provide new evidence for the association between plasticity dysregulation and functional cortical connectivity, and the importance of these networks in the pathophysiology of schizophrenia.
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Affiliation(s)
- Alkomiet Hasan
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Munich, Germany; Department of Psychiatry and Psychotherapy, Georg-August University, Goettingen, Germany.
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Ray D, Ram D. Electrophysiological examination of Formal Thought Disorder in schizophrenia. Asian J Psychiatr 2012; 5:327-38. [PMID: 23174441 DOI: 10.1016/j.ajp.2012.07.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 06/18/2012] [Accepted: 07/07/2012] [Indexed: 10/27/2022]
Abstract
Quantitave EEG profile was recorded for 60 age and sex matched drug free/naive schizophrenia patients, divided into two groups based on the presence and absence of Formal Thought Disorder (FTD) and a group of 30 matched healthy participants. Coherence and power spectrum analysis revealed that as compared to normal controls, schizophrenia patients with FTD had decreased regional power and intra hemispheric coherence; those without FTD had increased regional power and increased intra hemispheric coherence. Inter hemispheric coherence was greater in schizophrenia patients with FTD and lesser in those without FTD, as compared to healthy participants. The data were interpreted in terms of neural dis-connection which in FTD can be attributed to the existence of both a deficit and excess of neural connections, which compensate each other.
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Affiliation(s)
- Deepshikha Ray
- Department of Psychology, University of Calcutta, Kolkata, India.
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Hoptman MJ, Zuo XN, D’Angelo D, Mauro CJ, Butler PD, Milham MP, Javitt DC. Decreased interhemispheric coordination in schizophrenia: a resting state fMRI study. Schizophr Res 2012; 141:1-7. [PMID: 22910401 PMCID: PMC3446206 DOI: 10.1016/j.schres.2012.07.027] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 07/18/2012] [Accepted: 07/20/2012] [Indexed: 01/22/2023]
Abstract
Schizophrenia has been increasingly conceptualized as a disorder of brain connectivity, in large part due to findings emerging from white matter and functional connectivity (FC) studies. This work has focused primarily on within-hemispheric connectivity, however some evidence has suggested abnormalities in callosal structure and interhemispheric interaction. Here we examined functional connectivity between homotopic points in the brain using a technique called voxel-mirrored homotopic connectivity (VMHC). We performed VMHC analyses on resting state fMRI data from 23 healthy controls and 25 patients with schizophrenia or schizoaffective disorder. We found highly significant reductions in VMHC in patients for a number of regions, particularly the occipital lobe, the thalamus, and the cerebellum. No regions of increased VMHC were detected in patients. VMHC in the postcentral gyrus extending into the precentral gyrus was correlated with PANSS Total scores. These results show substantial impairment of interhemispheric coordination in schizophrenia.
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Affiliation(s)
- Matthew J. Hoptman
- Schizophrenia Research Division, Nathan Kline Institute, Orangeburg, NY,Department of Psychiatry, New York University School of Medicine, New York, NY
| | - Xi-Nian Zuo
- Laboratory for Functional Connectome and Development, Key Laboratory of Behavioral Science, Magnetic Resonance Imaging Research Center, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Debra D’Angelo
- Schizophrenia Research Division, Nathan Kline Institute, Orangeburg, NY
| | - Cristina J. Mauro
- Schizophrenia Research Division, Nathan Kline Institute, Orangeburg, NY
| | - Pamela D. Butler
- Schizophrenia Research Division, Nathan Kline Institute, Orangeburg, NY,Department of Psychiatry, New York University School of Medicine, New York, NY
| | - Michael P. Milham
- Schizophrenia Research Division, Nathan Kline Institute, Orangeburg, NY,Child Mind Institute, New York, NY
| | - Daniel C. Javitt
- Schizophrenia Research Division, Nathan Kline Institute, Orangeburg, NY,Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY
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Wamsley EJ, Tucker MA, Shinn AK, Ono KE, McKinley SK, Ely AV, Goff DC, Stickgold R, Manoach DS. Reduced sleep spindles and spindle coherence in schizophrenia: mechanisms of impaired memory consolidation? Biol Psychiatry 2012; 71:154-61. [PMID: 21967958 PMCID: PMC3561714 DOI: 10.1016/j.biopsych.2011.08.008] [Citation(s) in RCA: 311] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 07/15/2011] [Accepted: 08/13/2011] [Indexed: 11/27/2022]
Abstract
BACKGROUND Sleep spindles are thought to induce synaptic changes and thereby contribute to memory consolidation during sleep. Patients with schizophrenia show dramatic reductions of both spindles and sleep-dependent memory consolidation, which may be causally related. METHODS To examine the relations of sleep spindle activity to sleep-dependent consolidation of motor procedural memory, 21 chronic, medicated schizophrenia outpatients and 17 healthy volunteers underwent polysomnography on two consecutive nights. On the second night, participants were trained on the finger-tapping motor sequence task (MST) at bedtime and tested the following morning. The number, density, frequency, duration, amplitude, spectral content, and coherence of stage 2 sleep spindles were compared between groups and examined in relation to overnight changes in MST performance. RESULTS Patients failed to show overnight improvement on the MST and differed significantly from control participants who did improve. Patients also exhibited marked reductions in the density (reduced 38% relative to control participants), number (reduced 36%), and coherence (reduced 19%) of sleep spindles but showed no abnormalities in the morphology of individual spindles or of sleep architecture. In patients, reduced spindle number and density predicted less overnight improvement on the MST. In addition, reduced amplitude and sigma power of individual spindles correlated with greater severity of positive symptoms. CONCLUSIONS The observed sleep spindle abnormalities implicate thalamocortical network dysfunction in schizophrenia. In addition, the findings suggest that abnormal spindle generation impairs sleep-dependent memory consolidation in schizophrenia, contributes to positive symptoms, and is a promising novel target for the treatment of cognitive deficits in schizophrenia.
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Affiliation(s)
- Erin J. Wamsley
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA 02215, Harvard Medical School, Boston, MA, 02215
| | - Matthew A. Tucker
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA 02215, Harvard Medical School, Boston, MA, 02215
| | - Ann K. Shinn
- Psychotic Disorders Division, McLean Hospital, Belmont, MA 02478
| | - Kim E. Ono
- Department of Psychiatry, Massachusetts General Hospital, Charlestown, MA 02129
| | - Sophia K. McKinley
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA 02215, Harvard Medical School, Boston, MA, 02215
| | - Alice V. Ely
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA 02215, Harvard Medical School, Boston, MA, 02215
| | - Donald C. Goff
- Department of Psychiatry, Massachusetts General Hospital, Charlestown, MA 02129
| | - Robert Stickgold
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA 02215, Harvard Medical School, Boston, MA, 02215
| | - Dara S. Manoach
- Department of Psychiatry, Massachusetts General Hospital, Charlestown, MA 02129,Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA 02129
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Schwindinger WF, Mirshahi UL, Baylor KA, Sheridan KM, Stauffer AM, Usefof S, Stecker MM, Mirshahi T, Robishaw JD. Synergistic roles for G-protein γ3 and γ7 subtypes in seizure susceptibility as revealed in double knock-out mice. J Biol Chem 2011; 287:7121-33. [PMID: 22207761 DOI: 10.1074/jbc.m111.308395] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The functions of different G-protein αβγ subunit combinations are traditionally ascribed to their various α components. However, the discovery of similarly diverse γ subtypes raises the possibility that they may also contribute to specificity. To test this possibility, we used a gene targeting approach to determine whether the closely related γ(3) and γ(7) subunits can perform functionally interchangeable roles in mice. In contrast to single knock-out mice that show normal survival, Gng3(-/-)Gng7(-/-) double knock-out mice display a progressive seizure disorder that dramatically reduces their median life span to only 75 days. Biochemical analyses reveal that the severe phenotype is not due to redundant roles for the two γ subunits in the same signaling pathway but rather is attributed to their unique actions in different signaling pathways. The results suggest that the γ(3) subunit is a component of a G(i/o) protein that is required for γ-aminobutyric acid, type B, receptor-regulated neuronal excitability, whereas the γ(7) subunit is a component of a G(olf) protein that is responsible for A(2A) adenosine or D(1) dopamine receptor-induced neuro-protective response. The development of this mouse model offers a novel experimental framework for exploring how signaling pathways integrate to produce normal brain function and how their combined dysfunction leads to spontaneous seizures and premature death. The results underscore the critical role of the γ subunit in this process.
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Hinkley LBN, Vinogradov S, Guggisberg AG, Fisher M, Findlay AM, Nagarajan SS. Clinical symptoms and alpha band resting-state functional connectivity imaging in patients with schizophrenia: implications for novel approaches to treatment. Biol Psychiatry 2011; 70:1134-42. [PMID: 21861988 PMCID: PMC3327723 DOI: 10.1016/j.biopsych.2011.06.029] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 05/18/2011] [Accepted: 06/01/2011] [Indexed: 12/20/2022]
Abstract
BACKGROUND Schizophrenia (SZ) is associated with functional decoupling between cortical regions, but we do not know whether and where this occurs in low-frequency electromagnetic oscillations. The goal of this study was to use magnetoencephalography (MEG) to identify brain regions that exhibit abnormal resting-state connectivity in the alpha frequency range in patients with schizophrenia and investigate associations between functional connectivity and clinical symptoms in stable outpatient participants. METHODS Thirty patients with SZ and 15 healthy comparison participants were scanned in resting-state MEG (eyes closed). Functional connectivity MEG source data were reconstructed globally in the alpha range, quantified by the mean imaginary coherence between a voxel and the rest of the brain. RESULTS In patients, decreased connectivity was observed in left prefrontal cortex (PFC) and right superior temporal cortex, whereas increased connectivity was observed in left extrastriate cortex and the right inferior PFC. Functional connectivity of left inferior parietal cortex was negatively related to positive symptoms. Low left PFC connectivity was associated with negative symptoms. Functional connectivity of midline PFC was negatively correlated with depressed symptoms. Functional connectivity of right PFC was associated with other (cognitive) symptoms. CONCLUSIONS This study demonstrates direct functional disconnection in SZ between specific cortical fields within low-frequency resting-state oscillations. Impaired alpha coupling in frontal, parietal, and temporal regions is associated with clinical symptoms in these stable outpatients. Our findings indicate that this level of functional disconnection between cortical regions is an important treatment target in SZ.
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Affiliation(s)
- Leighton B N Hinkley
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California 94143, USA
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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: 122] [Impact Index Per Article: 8.1] [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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Galderisi S, Mucci A, Volpe U, Boutros N. Evidence-based medicine and electrophysiology in schizophrenia. Clin EEG Neurosci 2009; 40:62-77. [PMID: 19534300 DOI: 10.1177/155005940904000206] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In research on schizophrenia electrophysiological measures have been investigated to identify biomarkers of the disorder, indices enabling differential diagnosis among psychotic disorders, prognostic indicators or endophenotypes. The present systematic review will focus on the most largely studied electrophysiological indices, i.e., qualitative or quantitative (limited to spectral analysis) EEG and the P300 event-related potential. The PubMed clinical query was used with research methodology filters for each of the following categories: diagnosis/prognosis/ aetiology and a broad sensitive search strategy. The key-words: SCHIZOPHRENIA AND EEG/P3/P300 were used. The search results were then narrowed by including the terms "human" and "English language", and cross-referenced. Systematic reviews and meta-analyses, when available, were also used for cross-referencing. Case reports and studies irrelevant to the topics and methodologies under examination were excluded. The remaining papers were screened to verify the eligibility for this systematic review. Inclusion criteria were: a) a diagnosis of schizophrenia confirmed by DSM-III/ICD-9 criteria (or later editions of the same classification systems); b) the inclusion of both a schizophrenia study group and an healthy control group (when appropriate, i.e., for P300 and quantitative EEG); c) qualitative or spectral EEG findings and amplitude measures for P300. The included studies were then reviewed to verify homogeneity of the results, as well as the presence of the information needed for the present systematic review and meta-analysis. Previous reviews and studies meeting the above requirements (n = 22 for qualitative EEG; n = 45 for spectral EEG and n = 132 for P300) were classified according to the Oxford Centre for Evidence-based Medicine (EBM) levels of evidence criteria. For qualitative EEG as a diagnostic test, the majority of studies predated the introduction of DSM-III and were excluded from the review. Few post DSM-III studies investigated the usefulness of qualitative EEG in the differential diagnosis between schizophrenia and psychosis due to general medical condition. None of them was Oxford CEBM level 3b (non-consecutive-study or cohort-study without consistently-applied reference standard) or better (exploratory or validating cohort-study). No meta-analysis could be conducted due to the lack of reliable quantification methods in the reviewed studies. For spectral EEG as a diagnostic test, most studies qualified as level 4 (case-control study with poor reference standard), and only 24% as level 3b or better. An increase of slow activity in patients is reported by most of these studies. As to meta-analyses examining 29 studies, with 32 independent samples for the delta band and 35 for the theta band, a moderate effect size was found and only 1 study yielded findings in the opposite direction for both measures. There was no identified source for the discrepancy. The analysis of moderator factors included medication, band frequency limits, spectral parameters and disease stage. The medication status was significant for the theta band but the effect was unclear as findings for drug-naïve and drug-free patients were in a different direction. Chronicity had a significant effect on both delta and theta bands, with slow activity increase larger in chronic than in first episode patients. For P3 amplitude reduction as a diagnostic index, 63% of the studies qualified as level 3b or better. Meta-analysis (52 studies, 60 independent samples) results demonstrated a large effect size. None of the studies reported opposite findings. The analysis of moderator factors, including medication status and disease stage, revealed no significant effect on data heterogeneity. In conclusion, the examined indices are good candidates but are not ready yet for clinical applications aimed to improve present diagnostic standards for schizophrenia. Further research carried out according to adequate methodological standards and based on large scale multi-center studies is mandatory.
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Affiliation(s)
- Silvana Galderisi
- Department of Psychiatry, University of Naples SUN, Largo Madonna Grazie, Naples, Italy.
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Alfimova MV, Uvarova LG. Changes in EEG spectral power on perception of neutral and emotional words in patients with schizophrenia, their relatives, and healthy subjects from the general population. ACTA ACUST UNITED AC 2008; 38:533-40. [PMID: 18607745 DOI: 10.1007/s11055-008-9013-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Accepted: 03/12/2007] [Indexed: 11/30/2022]
Abstract
EEG correlates of impairments in the processing of emotiogenic information which might reflect a genetic predisposition to schizophrenia were sought by studying the dynamics of EEG rhythm powers on presentation of neutral and emotional words in 36 patients with schizophrenia, 50 of their unaffected first-degree relatives, and 47 healthy subjects without any inherited predisposition to psychoses. In controls, passive hearing of neutral words produced minimal changes in cortical rhythms, predominantly in the form of increases in the power levels of slow and fast waves, while perception of emotional words was accompanied by generalized reductions in the power of the alpha and beta(1) rhythms and regionally specific suppression of theta and beta(2) activity. Patients and their relatives demonstrated reductions in power of alpha and beta(1) activity, with an increase in delta power on hearing both groups of words. Thus, differences in responses to neutral and emotional words in patients and their relatives were weaker, because of increased reactions to neutral words. These results may identify EEG reflections of pathology of involuntary attention, which is familial and, evidently, inherited in nature. No reduction in reactions to emotiogenic stimuli was seen in patients' families.
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Affiliation(s)
- M V Alfimova
- Scientific Center for Mental Health, Russian Academy of Medical Sciences, Moscow, Russia.
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Honea RA, Meyer-Lindenberg A, Hobbs KB, Pezawas L, Mattay VS, Egan MF, Verchinski B, Passingham RE, Weinberger DR, Callicott JH. Is gray matter volume an intermediate phenotype for schizophrenia? A voxel-based morphometry study of patients with schizophrenia and their healthy siblings. Biol Psychiatry 2008; 63:465-74. [PMID: 17689500 PMCID: PMC2390785 DOI: 10.1016/j.biopsych.2007.05.027] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Revised: 04/30/2007] [Accepted: 05/22/2007] [Indexed: 02/06/2023]
Abstract
BACKGROUND Shared neuropathological characteristics of patients with schizophrenia and their siblings might represent intermediate phenotypes that could be used to investigate genetic susceptibility to the illness. We sought to discover previously unidentified gray matter volume differences in patients with schizophrenia and their siblings with optimized voxel-based morphometry. METHODS We studied 169 patients with schizophrenia, 213 of their unaffected siblings, and 212 healthy volunteers from the Clinical Brain Disorders Branch/National Institute of Mental Health Genetic Study of Schizophrenia with magnetic resonance imaging. RESULTS Patients with schizophrenia had significant regional gray matter decreases in the frontal, temporal, and parietal cortices compared with healthy volunteers. Their unaffected siblings tended to share gray matter decreases in the medial frontal, superior temporal, and insular cortices, but these decreases were not significant after correction for multiple comparisons, even when we looked at a subgroup of siblings with a past history of mood disorder. As an exploratory analysis, we estimated heritability with regions of interest from the VBM analysis as well as from the hippocampus. Hippocampal volume was significantly correlated within sibling-pairs. CONCLUSIONS Our findings confirm and extend previous voxel-based morphometry analyses in ill subjects with schizophrenia. Furthermore, these data argue that although siblings might share some regional gray matter decreases with their affected siblings, the pattern of regional differences might be a weak intermediate phenotype for schizophrenia.
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Affiliation(s)
- Robyn A Honea
- Genes, Cognition and Psychosis Program, National Institute of Mental Health, Division of Intramural Research, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892-1364, USA
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The status of spectral EEG abnormality as a diagnostic test for schizophrenia. Schizophr Res 2008; 99:225-37. [PMID: 18160260 PMCID: PMC2288752 DOI: 10.1016/j.schres.2007.11.020] [Citation(s) in RCA: 207] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2007] [Revised: 11/08/2007] [Accepted: 11/14/2007] [Indexed: 11/20/2022]
Abstract
OBJECTIVE A literature review was conducted to ascertain whether or not EEG spectral abnormalities are consistent enough to warrant additional effort towards developing them into a clinical diagnostic test for schizophrenia. METHODS Fifty three papers met criteria for inclusion into the review and 15 were included in a meta-analysis of the degree of significance of EEG deviations as compared to healthy controls. Studies were classified based on a 4-step approach based on guidelines for evaluating the clinical usefulness of a diagnostic test. RESULTS Our review and meta-analysis revealed that most of the abnormalities are replicated in the expected directions with the most consistent results related to the increased preponderance of slow rhythms in schizophrenia patients. This effect remained consistent in un-medicated patients. Only a small number of studies provided data on the sensitivity and specificity of the findings in differentiating among the psychiatric disorders that frequently appear on the same differential diagnostic list as schizophrenia (Step 3 studies). No multicenter studies using standardized assessment criteria were found (Step 4 studies). CONCLUSIONS Additional Step 3 and Step 4 studies are needed to draw conclusions on the usefulness of EEG spectral abnormalities as a diagnostic test for schizophrenia.
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Konrad A, Winterer G. Disturbed structural connectivity in schizophrenia primary factor in pathology or epiphenomenon? Schizophr Bull 2008; 34:72-92. [PMID: 17485733 PMCID: PMC2632386 DOI: 10.1093/schbul/sbm034] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Indirect evidence for disturbed structural connectivity of subcortical fiber tracts in schizophrenia has been obtained from functional neuroimaging and electrophysiologic studies. During the past few years, new structural imaging methods have become available. Diffusion tensor imaging and magnetization transfer imaging (MTI) have been used to investigate directly whether fiber tract abnormalities are indeed present in schizophrenia. To date, findings are inconsistent that may express problems related to methodological issues and sample size. Also, pathological processes detectable with these new techniques are not yet well understood. Nevertheless, with growing evidence of disturbed structural connectivity, myelination has been in the focus of postmortem investigations. Several studies have shown a significant reduction of oligodendroglial cells and ultrastructural alterations of myelin sheats in schizophrenia. There is also growing evidence for abnormal expression of myelin-related genes in schizophrenia: Neuregulin (NRG1) is important for oligodendrocyte development and function, and altered expression of erbB3, one of the NRG1 receptors, has been shown in schizophrenia patients. This is consistent with recent genetic studies suggesting that NRG1 may contribute to the genetic risk for schizophrenia. In conclusion, there is increasing evidence from multiple sides that structural connectivity might be pathologically changed in schizophrenia illness. Up to the present, however, it has not been possible to decide whether alterations of structural connectivity are intrinsically linked to the primary risk factors for schizophrenia or to secondary downstream effects (ie, degeneration of fibers secondarily caused by cortical neuronal dysfunction)-an issue that needs to be clarified by future research.
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Affiliation(s)
- Andreas Konrad
- Department of Psychiatry, Johannes Gutenberg-University, Mainz, Germany.
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Jalili M, Lavoie S, Deppen P, Meuli R, Do KQ, Cuénod M, Hasler M, De Feo O, Knyazeva MG. Dysconnection topography in schizophrenia revealed with state-space analysis of EEG. PLoS One 2007; 2:e1059. [PMID: 17957243 PMCID: PMC2020441 DOI: 10.1371/journal.pone.0001059] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Accepted: 10/01/2007] [Indexed: 12/02/2022] Open
Abstract
Background The dysconnection hypothesis has been proposed to account for pathophysiological mechanisms underlying schizophrenia. Widespread structural changes suggesting abnormal connectivity in schizophrenia have been imaged. A functional counterpart of the structural maps would be the EEG synchronization maps. However, due to the limits of currently used bivariate methods, functional correlates of dysconnection are limited to the isolated measurements of synchronization between preselected pairs of EEG signals. Methods/Results To reveal a whole-head synchronization topography in schizophrenia, we applied a new method of multivariate synchronization analysis called S-estimator to the resting dense-array (128 channels) EEG obtained from 14 patients and 14 controls. This method determines synchronization from the embedding dimension in a state-space domain based on the theoretical consequence of the cooperative behavior of simultaneous time series—the shrinking of the state-space embedding dimension. The S-estimator imaging revealed a specific synchronization landscape in schizophrenia patients. Its main features included bilaterally increased synchronization over temporal brain regions and decreased synchronization over the postcentral/parietal region neighboring the midline. The synchronization topography was stable over the course of several months and correlated with the severity of schizophrenia symptoms. In particular, direct correlations linked positive, negative, and general psychopathological symptoms to the hyper-synchronized temporal clusters over both hemispheres. Along with these correlations, general psychopathological symptoms inversely correlated within the hypo-synchronized postcentral midline region. While being similar to the structural maps of cortical changes in schizophrenia, the S-maps go beyond the topography limits, demonstrating a novel aspect of the abnormalities of functional cooperation: namely, regionally reduced or enhanced connectivity. Conclusion/Significance The new method of multivariate synchronization significantly boosts the potential of EEG as an imaging technique compatible with other imaging modalities. Its application to schizophrenia research shows that schizophrenia can be explained within the concept of neural dysconnection across and within large-scale brain networks.
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Affiliation(s)
- Mahdi Jalili
- École Polytechnique Fédérale de Lausanne (EPFL), IC – School of Computer and Communication Sciences, Laboratory of Nonlinear Systems (ICLANOS), Lausanne, Switzerland
| | - Suzie Lavoie
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Patricia Deppen
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Reto Meuli
- Department of Radiology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Kim Q. Do
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Michel Cuénod
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Martin Hasler
- École Polytechnique Fédérale de Lausanne (EPFL), IC – School of Computer and Communication Sciences, Laboratory of Nonlinear Systems (ICLANOS), Lausanne, Switzerland
| | - Oscar De Feo
- Microelectronic Engineering, University College Cork, Cork City, Ireland
| | - Maria G. Knyazeva
- Department of Radiology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
- Department of Neurology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
- * To whom correspondence should be addressed. E-mail:
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Ma X, Sun J, Yao J, Wang Q, Hu X, Deng W, Sun X, Liu X, Murray RM, Collier DA, Li T. A quantitative association study between schizotypal traits and COMT, PRODH and BDNF genes in a healthy Chinese population. Psychiatry Res 2007; 153:7-15. [PMID: 17604122 DOI: 10.1016/j.psychres.2007.02.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Revised: 12/14/2006] [Accepted: 02/03/2007] [Indexed: 11/21/2022]
Abstract
Previous studies have suggested that catechol-O-methyltransferase (COMT), proline dehydrogenase (PRODH), and brain-derived neurotrophic factor (BDNF) genes are possible susceptibility genes for schizophrenia. We hypothesized that these genes are also associated with schizotypal traits, which are heritable and related to schizophrenia. We genotyped five single nucleotide polymorphism (SNPs) from the COMT, PRODH and BDNF genes, and performed a series of association analyses between alleles, genotypes or haplotypes, and quantitative schizotypal trait scores derived from the Schizotypal Personality Questionnaire (SPQ), in 465 Chinese healthy subjects. We found that 'years of education' was a major influence on seven out of nine schizotypal components, three schizotypal factors and the total SPQ scores. Molecular genetic analysis of COMT, PRODH and BDNF genes showed no significant effects of any variants on schizotypal components or factors of SPQ after correction for multiple testing, although there were weak association between COMT Val158Met (rs4680G/A) and the odd speech subscale (allele-wise, P=0.04; genotype-wise, P=0.049), between COMT Val158Met (rs4680G/A) and the suspiciousness subscale (genotype-wise, P=0.024), and between BDNF Val66Met and the Factor 2 interpersonal measure (genotype-wise, P=0.027) before correction. Furthermore, we found SNP Val158Met (rs4680) of the COMT gene significantly influenced the scores of some of schizotypal traits including total SPQ score, the disorganization factor and the constricted affect subscale in male subjects only. However, the effect was in the opposite direction of an earlier association with the SPQ reported by Avramopoulos et al. [Avramopoulos, D., Stefanis, N.C., Hantoumi, I., Smyrnis, N., Evdokimidis, I., Stefanis, C.N., 2002. Higher scores of self reported schizotypy in healthy young males carrying the COMT high activity allele. Molecular Psychiatry 7, 706-711]. We conclude that SNP Val158Met (rs4680) in the COMT gene may be associated with some schizotypal traits in male subjects, but our results are not conclusive.
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Affiliation(s)
- Xiaohong Ma
- Psychiatric Laboratory and Department of Psychiatry, West China Hospital, Sichuan University, Chengdu, Sichuan, PR China
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Micheloyannis S, Pachou E, Stam CJ, Breakspear M, Bitsios P, Vourkas M, Erimaki S, Zervakis M. Small-world networks and disturbed functional connectivity in schizophrenia. Schizophr Res 2006; 87:60-6. [PMID: 16875801 DOI: 10.1016/j.schres.2006.06.028] [Citation(s) in RCA: 311] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2006] [Revised: 06/03/2006] [Accepted: 06/18/2006] [Indexed: 12/23/2022]
Abstract
Disturbances in "functional connectivity" have been proposed as a major pathophysiological mechanism for schizophrenia, and in particular, for cognitive disorganization. Detection and estimation of these disturbances would be of clinical interest. Here we characterize the spatial pattern of functional connectivity by computing the "synchronization likelihood" (SL) of EEG at rest and during performance of a 2Back working memory task using letters of the alphabet presented on a PC screen in subjects with schizophrenia and healthy controls. The spatial patterns of functional connectivity were then characterized with graph theoretical measures to test whether a disruption of an optimal spatial pattern ("small-world") of the functional connectivity network underlies schizophrenia. Twenty stabilized patients with schizophrenia, who were able to work, and 20 healthy controls participated in the study. During the working memory (WM) task healthy subjects exhibited small-world properties (a combination of local clustering and high overall integration of the functional networks) in the alpha, beta and gamma bands. These properties were not present in the schizophrenia group. These findings are in accordance with a partially inadequate organization of neuronal networks in subjects with schizophrenia. This method could be helpful for diagnosis and evaluation of the severity of the disease, as well as understanding the pathophysiologic mechanisms underlying cognitive dysfunction in schizophrenia.
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Winterer G, Egan MF, Kolachana BS, Goldberg TE, Coppola R, Weinberger DR. Prefrontal electrophysiologic "noise" and catechol-O-methyltransferase genotype in schizophrenia. Biol Psychiatry 2006; 60:578-84. [PMID: 16730334 DOI: 10.1016/j.biopsych.2006.03.023] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Revised: 02/28/2006] [Accepted: 03/07/2006] [Indexed: 11/28/2022]
Abstract
BACKGROUND Increased variability of stimulus-induced prefrontal electromagnetic activity ("noise") has been associated with genetic risk for schizophrenia. On the basis of animal experiments and computational models, we have predicted that this prefrontal "noise" phenotype would be related to variation in prefrontal dopamine (DA) signaling, which itself might be abnormal in schizophrenia. In the present study, the effect of a functional single nucleotide polymorphism (val(108/158)met) within the catechol-O-methyltransferase (COMT) gene on prefrontal "noise" was examined, because the COMT enzyme is involved in cortical synaptic dopamine metabolism and weakly predictive of risk for schizophrenia. METHODS A Caucasian sample comprising 112 unrelated normal subjects, 83 schizophrenic probands, and 87 of their unaffected siblings was investigated, all of whom had measures of prefrontal "noise" estimated from event-related electroencephalogram during an auditory oddball task. RESULTS The val(108/158)met genotype was significantly associated with prefrontal "noise"; homozygous Val-carriers had greatest prefrontal "noise" values; odds ratio (OR) = 2.37 (95% confidence interval [CI] 1.37-4.10), p = 003. The genotype-phenotype association was stronger when only considering male subjects with an OR = 3.37 (95% CI: 1.63-6.98), p = 002. CONCLUSIONS The results suggest that COMT genotype impacts the level of prefrontal physiologic "noise."
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Affiliation(s)
- Georg Winterer
- Genes, Cognition and Psychosis Program, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, USA
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Higashima M, Takeda T, Kikuchi M, Nagasawa T, Koshino Y. Functional connectivity between hemispheres and schizophrenic symptoms: a longitudinal study of interhemispheric EEG coherence in patients with acute exacerbations of schizophrenia. Clin EEG Neurosci 2006; 37:10-5. [PMID: 16475479 DOI: 10.1177/155005940603700104] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To clarify whether interhemispheric electroencephalogram (EEG) coherence reflecting functional connectivity between the two cerebral hemispheres can change in a symptom-dependent manner in schizophrenia, we measured resting EEG and symptom severity twice at an average interval of 32.7 days during the course of treatment in 15 patients hospitalized for acute exacerbations of schizophrenia. Symptom severity was estimated quantitatively by means of the Brief Psychiatric Rating Scale (BPRS). Correlation analysis showed that increases in the beta-band coherence for frontal electrode pairs during the treatment were associated with improvement in the total score and the score on the positive subscale of BPRS. This result suggests that functional disconnection between the left and right frontal lobes may be related to the generation of psychotic symptoms and can normalize following antipsychotic treatment.
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Affiliation(s)
- Masato Higashima
- Department of Psychiatry and Neurobiology, Graduate School of Medical Science, Kanazawa University, Japan.
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Sritharan A, Line P, Sergejew A, Silberstein R, Egan G, Copolov D. EEG coherence measures during auditory hallucinations in schizophrenia. Psychiatry Res 2005; 136:189-200. [PMID: 16125789 DOI: 10.1016/j.psychres.2005.05.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2004] [Revised: 04/20/2005] [Accepted: 05/05/2005] [Indexed: 10/25/2022]
Abstract
We studied the change in EEG alpha-band average coherence between auditory hallucination (AH) and non-auditory hallucination (non-AH) states in seven auditory hallucinating schizophrenia patients. Four cortical regions were considered based on the existing dominant models for auditory hallucinations, the inner speech model and the central auditory processing deficit (CAPD) model. Coherences between electrodes located over Broca's area (BA 44/45) and Wernicke's area (BA 22/42) and between electrodes located over left-right temporal cortices were examined. There was no significant change observed in the coherence between Broca's and Wernicke's areas, but a significant increase was observed in coherence between the left and right superior temporal cortices during AHs compared with non-AHs, suggesting increased bilateral coherence between auditory cortical areas. Since coherence is a pairwise measure of functional correlation between regions, our findings suggest abnormally increased synchrony between the left and right auditory cortices during AHs in schizophrenia. Further, a significant increase in relative power was observed in the left, but not in the right auditory cortex during AHs. Thus our findings support the CAPD model and are consistent with that which postulate reduced prosodic processing during AHs.
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Affiliation(s)
- Anusha Sritharan
- Mental Health Research Institute, Locked Bag 11, Parkville, Victoria 3052, Australia
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