Cortical event-related potentials in preclinical familial Alzheimer disease.
OBJECTIVE
To define changes in cortical function in persons inheriting familial Alzheimer disease (FAD) mutations before the onset of cognitive decline.


METHODS
Twenty-six subjects with a family history of FAD were divided into 2 subgroups according to genotype (FAD mutation carriers, n = 15; FAD noncarriers, n = 11). Subjects were given standardized tests of cognitive function and the Clinical Dementia Rating scale (CDR). Sensory (P50, N100, P200) and cognitive (N200, P300) event-related potentials were recorded during an auditory discrimination task. Amplitudes and latencies of cortical potentials were compared among FAD mutation carriers and noncarriers.


RESULTS
FAD mutation carriers and noncarriers did not significantly differ in age or on measures of cognitive function, but FAD carriers had a greater incidence of 0.5 CDR scores (1/10 noncarriers, 5/15 carriers). Relative to noncarriers, FAD mutation carriers had significantly longer latencies of the N100, P200, N200, and P300 components, and smaller slow wave amplitudes. Subanalyses of subjects having CDR scores of 0.0 also showed latency increases in FAD mutation carriers.


CONCLUSIONS
Auditory sensory and cognitive cortical potentials in persons with familial Alzheimer disease (FAD) mutations are abnormal approximately 10 years before dementia will be manifest. Longer event-related potential latencies suggest slowing of cortical information processing in FAD mutation carriers.
Golob
E J
EJ
Department of Psychology, 3067 Percival Stern Hall, Tulane University, New Orleans, LA 70118, USA. egolob@tulane.edu
Ringman
J M
JM
Irimajiri
R
R
Bright
S
S
Schaffer
B
B
Medina
L D
LD
Starr
A
A
D000161:Acoustic Stimulation; D000328:Adult; D000544:Alzheimer Disease / Q000235:genetics* / Q000503:physiopathology*; D001307:Auditory Perception / Q000502:physiology*; D001921:Brain / Q000503:physiopathology*; D003071:Cognition / Q000502:physiology*; D004252:DNA Mutational Analysis; D004569:Electroencephalography; D018913:Event-Related Potentials, P300; D005071:Evoked Potentials; D005190:Family; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D009154:Mutation; D009483:Neuropsychological Tests; D013997:Time Factors