Cortical hypoactivation during resting EEG in schizophrenics but not in depressives and schizotypal subjects as revealed by low resolution electromagnetic tomography (LORETA).
This study was performed in order to address the question whether the newly introduced technique of low-resolution electromagnetic tomography (LORETA) is able to detect hypofrontality in schizophrenic patients. We investigated resting EEGs of 19 unmedicated schizophrenics and 20 normal subjects. For comparison, we also investigated 19 subjects with schizotypal personality and 30 unmedicated depressive patients. A significant increase of delta activity was found in schizophrenic patients over the whole cortex, most strongly in the anterior cingulate gyrus and temporal lobe (fusiform gyrus). Both schizotypal subjects and depressive subjects showed significantly less delta, theta and beta activity in the anterior cingulum, a decrease of alpha1 activity in the right temporal lobe and a decrease of alpha2 activity in the left temporal lobe. The results suggest general cortical hypoactivation, most pronounced in the anterior cingulate and temporal lobe in schizophrenics, whereas there is evidence for a complex, frequency-dependent spatial pattern of hyperactivation in schizotypal subjects and depressive patients. The results are discussed within a neurophysiological and methodological framework.
Mientus
Susanne
S
Department of Psychiatry, Free University of Berlin, Berlin, Germany.
Gallinat
Jürgen
J
Wuebben
Yvonne
Y
Pascual-Marqui
Roberto D
RD
Mulert
Christoph
C
Frick
Kurt
K
Dorn
Hans
H
Herrmann
Werner M
WM
Winterer
Georg
G
D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology*; D003866:Depressive Disorder / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D005583:Fourier Analysis; D005625:Frontal Lobe / Q000503:physiopathology; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000175:diagnosis / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D012569:Schizotypal Personality Disorder / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D012815:Signal Processing, Computer-Assisted; D013702:Temporal Lobe / Q000503:physiopathology; D014054:Tomography