Effects of cholinesterase inhibitors on visual attention in drivers with Alzheimer disease.

OBJECTIVE: We conducted a combined observational cohort and case-control study in patients with Alzheimer disease (AD) to assess the effects of acetylcholinesterase inhibitor (ChEI) treatment on cognitive functions important for driving.
METHODS: Performance of 24 outpatients with newly diagnosed (untreated) early-stage AD was compared before beginning ChEI (pre-ChEI) and after 3 months of therapy (post-ChEI) on a set of computerized tests of visual attention and executive function administered under both single-task and dual-task conditions. To address the limitation of a lack of an untreated control group in this observational cohort study, performance of 35 outpatients with newly diagnosed (untreated) early-stage AD (ChEI nonusers) were also compared with a demographically matched group of AD patients treated with stable doses of a ChEI (ChEI users) on these tasks.
RESULTS: Performance was consistently worse under dual-task than single-task conditions regardless of ChEI treatment status. However, ChEI treatment consistently affected specific components of attention within each test across both sets of comparisons: ChEI treatment enhanced simulated driving accuracy and was associated with significantly better visual search target detection accuracy and response time in both pre-ChEI-post-ChEI and users-nonusers treatment comparisons. Cholinesterase inhibitor treatment also improved overall time to complete a set of mazes while not affecting accuracy of completion.
CONCLUSIONS: Cholinesterase inhibitor treatment was associated with improvements in tests of executive function and visual attention. These findings could have important implications for patients who continue to drive in the early stages of AD.