Narkolepsie und Fahrtauglichkeit

Modafinil improves real driving performance in patients with hypersomnia: a randomized double-blind placebo-controlled crossover clinical trial

STUDY OBJECTIVE

Patients with excessive daytime sleepiness (EDS) are at high risk for driving accidents, and physicians are concerned by the effect of alerting drugs on driving skills of sleepy patients. No study has up to now investigated the effect of modafinil (a reference drug to treat EDS in patients with hypersomnia) on on-road driving performance of patients suffering from central hypersomnia. The objective is to evaluate in patients with central hypersomnia the effect of a wake-promoting drug on real driving performance and to assess the relationship between objective sleepiness and driving performance.

DESIGN AND PARTICIPANTS

Randomized, crossover, double-blind placebo-controlled trial conducted among 13 patients with narcolepsy and 14 patients with idiopathic hypersomnia. Patients were randomly assigned to receive modafinil (400 mg) or placebo for 5 days prior to the driving test. Each condition was separated by at least 3 weeks of washout.

MEASUREMENTS

Mean number of Inappropriate Line Crossings, Standard Deviation of Lateral Position of the vehicle and mean sleep latency in the Maintenance of Wakefulness Test were assessed.

RESULTS

Modafinil reduced the mean number of Inappropriate Line Crossings and Standard Deviation of Lateral Position of the vehicle compared to placebo (F(1,25) = 4.88, P < 0.05 and F(1,25) = 3.87, P = 0.06 tendency). Mean sleep latency at the Maintenance of Wakefulness Test significantly correlated with the mean number of Inappropriate Line Crossings (r = -0.41, P < 0.001).

CONCLUSIONS

Modafinil improves driving performance in patients with narcolepsy and idiopathic hypersomnia. The Maintenance of Wakefulness Test is a suitable clinical tool to assess fitness to drive in this population.

Begutachtung der Tagesschläfrigkeit bei neurologischen Erkrankungen und dem obstruktiven Schlafapnoesyndrom (OSAS)

Patients with increased daytime sleepiness are impaired in all areas of their social environment. Expert opinions are recommended for pension proceedings, regarding driving licenses as well as for restrictions at the workplace. All possibilities should be considered in the differential diagnosis of sleep disorders, which have to be treated before an expert opinion is submitted. Statutory regulations on evaluation of sleepiness are contained in the guidelines for assessing a patient's fitness to drive. The importance of daytime sleepiness in other occupations should be assessed according to the respective workplace. The patient should be informed of the appraisal with regard to career choice and workplace design. The expert thus has the responsible task of carrying out interdisciplinary differential diagnosis of pathological sleepiness and monitoring treatment success with appropriate test methods. In the present paper the legal guidelines in Germany and available test methods are presented.