EVOKED-POTENTIALS IN SUBJECTS AT RISK FOR ALZHEIMERS-DISEASE

Evoked potential (EP) changes accompanying dementing processes have be en documented in a number of studies. However, EPs have not been studi ed in subjects who are at heightened risk for the development of Alzhe imer's Disease (AD). Nineteen volunteers with no immediate family memb ers with a history of AD and 33 healthy subjects with at least one fir st-degree relative with AD were studied. Of the 33 subjects with a pos itive family history of AD, the illness of the sick relative was class ified as possible AD in 10 subjects, probable AD in 17 subjects, and d efinite (autopsy-proven) AD in 6 subjects. Mid-latency evoked potentia ls (P50, N100, and P200) and P300 event-related potentials were record ed in an oddball paradigm. The amplitudes of the P50 responses to the frequent stimuli and of the P300 responses were significantly higher i n the subjects whose relatives had definite AD as compared with the ot her three groups. The amplitude of the N100 component was also larger in the same group, but the difference was only statistically significa nt from the group of healthy volunteers without a family history of AD . A process of increased sensitivity to incoming stimuli may be reflec ted in the increased P50, N100, and P300 amplitudes in the subjects at increased risk for developing AD.