Negative symptoms and EEG alpha activity in schizophrenic patients

• Published in: Schizophrenia research 1992-10, Vol.8 (1), p.11-20
• Main Authors: Merrin, Edward L., Floyd, Thomas C.
• Format: Article
• Language: English
• Subjects: Adult; Adult and adolescent clinical studies; Aged; Alpha; Alpha Rhythm; Antipsychotic Agents - adverse effects; Antipsychotic Agents - therapeutic use; Arousal - drug effects; Arousal - physiology; Biological and medical sciences; Brain Mapping - instrumentation; Cerebral Cortex - drug effects; Cerebral Cortex - physiopathology; Dominance, Cerebral - drug effects; Dominance, Cerebral - physiology; Dose-Response Relationship, Drug; Dyskinesia, Drug-Induced - diagnosis; Dyskinesia, Drug-Induced - physiopathology; EEG; Electroencephalography - drug effects; Electroencephalography - instrumentation; Humans; Male; Medical sciences; Middle Aged; Negative symptoms; Psychiatric Status Rating Scales; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Psychoses; Reference Values; Schizophrenia; Schizophrenia - diagnosis; Schizophrenia - drug therapy; Schizophrenia - physiopathology; Schizophrenic Psychology; Signal Processing, Computer-Assisted
• ISSN: 0920-9964; 1573-2509
• DOI: 10.1016/0920-9964(92)90056-B

Quantitative analyses of electroencephalographic (EEG) recordings in schizophrenic patients have often demonstrated reduced alpha band (8–13 Hz) activity. However, this finding is not universal and there is some evidence that subgroups of schizophrenics may differ in overall or lateralized levels of EEG alpha activity. To investigate this issue, the authors examined relationships between clinical ratings performed at the time of EEG recording and resting alpha power and coherence in 14 medication free schizophrenic patients. Nine channels of previously recorded resting (eyes open) EEG were transformed to average reference prior to spectral analysis and transformed to source derivation prior to calculation of interelectrode coherences. Patients were rated with the Brief Psychiatric Rating Scale (BPRS), from which subscales corresponding to negative symptoms, positive symptoms, paranoia, and anxiety/depression were derived. Ratings and EEG measures were also obtained on 10 of the schizophrenic patients after neuroleptic treatment. Multiple regression with repeated measures was used to examine the influence of the subscale scores on bilateral log alpha power and both within- and between-hemisphere alpha coherence at selected locations. Prior to treatment, negative symptoms varied inversely with alpha power ( p