Attention deficit in Alzheimer's disease is not simulated by an anticholinergic/antihistaminergic drug and is distinct from deficits in healthy aging.
OBJECTIVE
To evaluate attention deficit in Alzheimer's disease (AD) and its relationship to attention deficits associated with aging and with medications altering alertness.


METHODS
Ten patients with probable AD, 10 healthy old controls, and 15 young controls performed a covert orienting of spatial attention task. Young controls performed the task an additional time after ingestion of diphenhydramine 1 mg/kg. Reaction times were obtained following valid, neutral, and invalid cues.


RESULTS
In all groups, the reaction times were shortest for the validly cued stimuli and longest for the invalidly cued stimuli. Additionally, the AD patients performed disproportionately worse following the invalid cue than did the control groups. Young controls given diphenhydramine had decreased subjective alertness, performed worse than they did before drug but better than the old controls or AD patients, and had no disproportionate impairment with the invalid cue.


CONCLUSIONS
AD patients have disproportionate problems shifting spatial attention compared with age-matched controls. Impaired attentional performance in AD cannot be simulated in young subjects by ingestion of a combined antihistamine/anticholinergic agent at a dose sufficient to produce significant changes in alertness.
Oken
B S
BS
Department of Neurology, Oregon Health Sciences University, Portland 97201.
Kishiyama
S S
SS
Kaye
J A
JA
Howieson
D B
DB
D000368:Aged; D000375:Aging / Q000523:psychology*; D000544:Alzheimer Disease / Q000523:psychology*; D000704:Analysis of Variance; D001288:Attention / Q000187:drug effects*; D004155:Diphenhydramine / Q000494:pharmacology; D005260:Female; D006633:Histamine Antagonists / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000494:pharmacology; D008875:Middle Aged; D010276:Parasympatholytics / Q000494:pharmacology*; D011930:Reaction Time; D012016:Reference Values
D006633:Histamine Antagonists; D010276:Parasympatholytics; D008774:Methylphenidate; D004155:Diphenhydramine