Effects of Alzheimer's disease and mild cognitive impairment on driving ability: a controlled clinical study by simulated driving test.
OBJECTIVE
To assess the effects of Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI) on simulated car driving ability.


METHODS
Twenty patients with a probable AD of mild severity (Clinical Dementia Rating, CDR = 1) were compared with 20 subjects with MCI (CD = 0.5), and a group of age-matched neurologically normal controls on a driving simulation task. Measures of driving competence included the length of run, the number of infractions (omission of stop at pedestrian crossings, speed limits violation), the number of stops at traffic lights, the mean time to collision, and the number of off-road events. Results in the driving competence measures were correlated with scores obtained from simple visual reaction times and mini-mental state examination (MMSE).


RESULTS
The patients with mild AD performed significantly worse than MCI subjects and controls on three simulated driving measures, length of run and mean time to collision (p < 0.001), and number of off-road events (p < 0.01). MCI subjects had only a significantly shorter time-to-collision than healthy controls (p < 0.001). Simple visual reaction times were significantly longer (p < 0.001) in patients with AD, compared to MCI and healthy controls, and showed a borderline significant relation (p = 0.05) with simulated driving scores. Driving performance in the three groups did not significantly correlate with MMSE score as measure of overall cognitive function.


CONCLUSIONS
Mild AD significantly impaired simulated driving fitness, while MCI limitedly affected driving performance. Unsafe driving behaviour in AD patients was not predicted by MMSE scores.
Frittelli
Cristina
C
Department of Neuroscience, Section of Neurology, University of Pisa, Pisa, Italy.
Borghetti
Davide
D
Iudice
Giovanni
G
Bonanni
Enrica
E
Maestri
Michelangelo
M
Tognoni
Gloria
G
Pasquali
Livia
L
Iudice
Alfonso
A
D000368:Aged; D000544:Alzheimer Disease / Q000523:psychology*; D001333:Automobile Driver Examination; D001334:Automobile Driving; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000523:psychology*; D003198:Computer Simulation; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D016743:Mental Competency; D012720:Severity of Illness Index