title: Abnormal oscillatory brain dynamics in schizophrenia: a sign of deviant communication in neural network?
abstract: BACKGROUND
  Slow waves in the delta (0.5-4 Hz) frequency range are indications of normal activity in sleep. In neurological disorders, focal electric and magnetic slow wave activity is generated in the vicinity of structural brain lesions. Initial studies, including our own, suggest that the distribution of the focal concentration of generators of slow waves (dipole density in the delta frequency band) also distinguishes patients with psychiatric disorders such as schizophrenia, affective disorders, and posttraumatic stress disorder.
  
  
  METHODS
  The present study examined the distribution of focal slow wave activity (ASWA: abnormal slow wave activity) in 116 healthy subjects, 76 inpatients with schizophrenic or schizoaffective diagnoses and 42 inpatients with affective (ICD-10: F3) or neurotic/reactive (F4) diagnoses using a newly refined measure of dipole density. Based on 5-min resting magnetoencephalogram (MEG), sources of activity in the 1-4 Hz frequency band were determined by equivalent dipole fitting in anatomically defined cortical regions.
  
  
  RESULTS
  Compared to healthy subjects the schizophrenia sample was characterized by significantly more intense slow wave activity, with maxima in frontal and central areas. In contrast, affective disorder patients exhibited less slow wave generators mainly in frontal and central regions when compared to healthy subjects and schizophrenia patients. In both samples, frontal ASWA were related to affective symptoms.
  
  
  CONCLUSIONS
  In schizophrenic patients, the regions of ASWA correspond to those identified for gray matter loss. This suggests that ASWA might be evaluated as a measure of altered neuronal network architecture and communication, which may mediate psychopathological signs.
authors.affiliation: Department of Psychology, University of Konstanz, PO Box D23 D-78457, Konstanz, Germany. brigitte.rockstroh@uni-konstanz.de
authors.forename: Brigitte S
authors.initials: BS
authors.lastname: Rockstroh
authors.forename: Christian
authors.initials: C
authors.lastname: Wienbruch
authors.forename: William J
authors.initials: WJ
authors.lastname: Ray
authors.forename: Thomas
authors.initials: T
authors.lastname: Elbert
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology*; D003700:Delta Rhythm; D004569:Electroencephalography; D005260:Female; D006760:Hospitalization; D006801:Humans; D015225:Magnetoencephalography / Q000295:instrumentation*; D008297:Male; D009415:Nerve Net / Q000503:physiopathology*; D012559:Schizophrenia / Q000503:physiopathology* / Q000534:rehabilitation