Bs. Oken et al., ATTENTION-DEFICIT IN ALZHEIMERS-DISEASE IS NOT SIMULATED BY AN ANTICHOLINERGIC ANTIHISTAMINERGIC DRUG AND IS DISTINCT FROM DEFICITS IN HEALTHY AGING/, Neurology, 44(4), 1994, pp. 657-662
Objective. To evaluate attention deficit in Alzheimer's disease (AD) a
nd its relationship to attention deficits associated with aging and wi
th 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 tas
k an additional time after ingestion of diphenhydramine 1 mg/kg. React
ion times were obtained following valid, neutral, and invalid cues. Re
sults. 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 inv
alid cue than did the control groups. Young controls given diphenhydra
mine 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 p
atients have disproportionate problems shifting spatial attention comp
ared with age-matched controls. Impaired attentional performance in AD
cannot be simulated in young subjects by ingestion of a combined anti
histamine/anticholinergic agent at a dose sufficient to produce signif
icant changes in alertness.