An EEG approach to the neurodevelopmental hypothesis of schizophrenia studying schizophrenics, normal controls and adolescents

• Published in: Journal of psychiatric research Vol. 34; no. 1; pp. 57 - 73
• Main Authors: Koukkou, M., Federspiel, A., Bräker, E., Hug, C., Kleinlogel, H., Merlo, M.C.G., Lehmann, D.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2000; Elsevier
• Subjects: Adaptation, Psychological - physiology; Adolescent; Adult; Adult and adolescent clinical studies; Biological and medical sciences; Brain - abnormalities; Brain - physiopathology; Child; EEG centroid frequency; EEG reactivity; Electroencephalography; Female; First-episode, neuroleptic-naive schizophrenics; Functional Laterality - physiology; Humans; Male; Medical sciences; Memory Disorders - diagnosis; Memory Disorders - physiopathology; Nerve Net - abnormalities; Nerve Net - physiopathology; Neural networks; Neural Pathways - abnormalities; Neural Pathways - physiopathology; Neurodevelopmental models of schizophrenia; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Psychoses; Schizophrenia; Schizophrenia - diagnosis; Schizophrenia - physiopathology; Wakefulness - physiology; Working memory; EEG reactivity; EEG centroid frequency; First-episode, neuroleptic-naive schizophrenics; Working memory; Neural networks; Neurodevelopmental models of schizophrenia; Human; Healthy subject; Corticocortical connection; Pathogenesis; Central nervous system; Schizophrenia; Cognition; Electroencephalography; Developmental disorder; Neural network; Psychosis; Electrodiagnosis; Theoretical model; Adolescent; Information processing; Neurological disorder; Inaugural sign; Comparative study; Brain (vertebrata)
• ISSN: 0022-3956; 1879-1379
• DOI: 10.1016/S0022-3956(99)00040-0

Based on an integrative brain model which focuses on memory-driven and EEG state-dependent information processing for the organisation of behaviour, we used the developmental changes of the awake EEG to further investigate the hypothesis that neurodevelopmental abnormalities (deviations in organisation and reorganisation of cortico–cortical connectivity during development) are involved in the pathogenesis of schizophrenia. First-episode, neuroleptic-naive schizophrenics and their matched controls and three age groups of normal adolescents were studied (total: 70 subjects). 19-channel EEG delta-theta, alpha and beta spectral band centroid frequencies during resting (baseline) and after verbal stimuli were used as measure of the level of attained complexity and momentary excitability of the neuronal network (working memory). Schizophrenics compared with all control groups showed lower delta-theta activity centroids and higher alpha and beta activity centroids. Reactivity centroids (centroid after stimulus minus centroid during resting) were used as measure of update of working memory. Schizophrenics showed partial similarities in delta-theta and beta reactivity centroids with the 11-year olds and in alpha reactivity centroids with the 13-year olds. Within the framework of our model, the results suggest multifactorially elicited imbalances in the level of excitability of neuronal networks in schizophrenia, resulting in network activation at dissociated complexity levels, partially regressed and partially prematurely developed. It is hypothesised that activation of age- and/or state-inadequate representations for coping with realities becomes manifest as productive schizophrenic symptoms. Thus, the results support some aspects of the neurodevelopmental hypothesis.