P2 flash visual evoked response delay may be a marker of cognitive dysfunction in healthy elderly volunteers.
In an earlier study, 31 healthy elderly volunteers had normal cognitive function as measured by the Mini-Mental State Examination. Twenty-seven returned for further memory testing using the Wechsler Memory Scale-Revised (WMS-R). The P2 latency of the flash visual evoked response was positively correlated with age (p = .0008), but was not significantly related to gender. Nine of these 27 putatively healthy subjects had a delayed P2, suggestive of dementia. Although unaware of any memory deficits, 5 of the 27 had WMS-R Visual Memory Span percentile scores 1 or more standard deviations less than age-matched controls. Four of the five also had a significantly delayed P2 component. This positive correlation, adjusted for age, between poor Visual Memory Span performance and a delayed P2 was statistically significant (p < .025). These findings suggest that a delayed P2 in putatively healthy subjects is indicative of a visuospatial deficit which might be a precursor of dementia later.
Moore
N C
NC
Mercer University School of Medicine, Macon, Georgia, USA.
Vogel
R L
RL
Tucker
K A
KA
Khairy
N M
NM
Coburn
K L
KL
D000368:Aged; D003072:Cognition Disorders / Q000175:diagnosis* / Q000503:physiopathology; D003704:Dementia / Q000175:diagnosis* / Q000503:physiopathology; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000502:physiology; D008609:Mental Status Schedule; D008875:Middle Aged; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D012815:Signal Processing, Computer-Assisted; D014888:Wechsler Scales