Comparison of driving simulator performance and neuropsychological testing in narcolepsy.

Daytime sleepiness and cataplexy can increase automobile accident rates in narcolepsy. Several countries have produced guidelines for issuing a driving license. The aim of the study was to compare driving simulator performance and neuropsychological test results in narcolepsy in order to evaluate their predictive value regarding driving ability. Thirteen patients with narcolepsy (age: [Formula: see text] years) and 10 healthy control patients (age: [Formula: see text] years) were investigated. By computer-assisted neuropsychological testing, vigilance, alertness and divided attention were assessed. In a driving simulator patients and controls had to drive on a highway for 60min (mean speed of 100km/h). Different weather and daytime conditions and obstacles were presented. Epworth Sleepiness Scale-Scores were significantly raised (narcolepsy patients: [Formula: see text], controls: [Formula: see text], [Formula: see text] ). The accident rate of the control patients increased ( [Formula: see text] versus [Formula: see text], [Formula: see text] ). Significant differences in concentration lapses (e.g. tracking errors and deviation from speed limit) could not be revealed ( [Formula: see text] versus [Formula: see text], pns). Follow-up investigation in five patients after an optimising therapy could demonstrate the decrease in accidents due to concentration lapses ( [Formula: see text] ). Neuropsychological testing (expressed as percentage compared to a standardised control population) revealed deficits in alertness ( [Formula: see text] ). Mean percentage scores of divided attention ( [Formula: see text] ) and vigilance ( [Formula: see text] ) were in a normal range. There was, however, a high inter-individual difference. There was no correlation between driving performance and neuropsychological test results or ESS Score. Neuropsychological test results did not significantly change in the follow-up. The difficulties encountered by the narcolepsy patient in remaining alert may account for sleep-related motor vehicle accidents. Driving simulator investigations are closely related to real traffic situations than isolated neuropsychological tests. At the present time the driving simulator seems to be a useful instrument judging driving ability especially in cases with ambiguous neuropsychological results. (Author/publisher)