[Brain evoked potentials in patients with Alzheimer's disease and schizophrenia: a comparative study].
OBJECTIVE
To investigate the differences of visual evoked potentials(VEP) and auditory evoked potentials(AEP) between patients with Alzheimer's disease and schizophrenics.


METHODS
Both VEP and AEP were elicited from 39 patients with Alzheimer's disease, 34 aged schizophrenics and 40 normally age-matched subjects.


RESULTS
The variability of waveforms of both VEP and AEP became increased within the AD group. The AD patients presented significantly delayed latencies (N2 and P3 of VEP; P1, N1, P2, N2 and P3 of AEP) as compared to the normal controls. The P2 amplitude of VEP of AD patients was 32% lower than that of schizophrenics and 57% lower than that of the controls. The P2 amplitude of AEP of AD patients was 36% lower than that of schizophrenics and 70% lower than that of the controls. Compared with the normal controls, the schizophrenics showed reduced VEP-P2 latency, prolonged N2 and P3 latencies of both VEP and AEP. The P2 amplitudes of VEP and AEP of schizophrenics were decreased by 16% and 20% respectively as compared to the normal controls.


CONCLUSIONS
The variations of VEP and AEP are a referential tool for diagnosing Alzheimer's disease and schizophrenia.
Chen
X
X
Shanghai Institute of Mental Health.
Zhang
M
M
Wang
J
J
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000503:physiopathology*; D005072:Evoked Potentials, Auditory; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D008297:Male; D012559:Schizophrenia / Q000503:physiopathology*