Facilitation of early and masking of late cortical responses in dementia.
Topographic differences in longlatency SSEP and flash VEP data are compared in 3 different psychiatric patient groups. Differences between schizophrenia and affective disorder are restricted to somatosensory P100 amplitude gradients along the antero-posterior axis. In contrast EP-differences between psychiatric patients and dementia are prominent, encompassing both late and early (< 100 ms) responses. Our flash P 2 and somatosensory P 3 data are in accordance with previous findings. Multi-modal positive responses with a latency of 40-80 ms are significantly increased in dementia. This facilitation suggests cortical dysfunction and/or subcortical gating impairment.
Van Sweden
B
B
Dept. Clin. Neurophysiology, Medical Centre St-Jozef, Bilzen, Belgium.
Van Erp
M G
MG
Bergen
E
E
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002540:Cerebral Cortex / Q000503:physiopathology*; D003704:Dementia / Q000503:physiopathology; D005073:Evoked Potentials, Somatosensory; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000503:physiopathology*; D008875:Middle Aged; D019964:Mood Disorders / Q000503:physiopathology; D011930:Reaction Time; D012559:Schizophrenia / Q000503:physiopathology