Driving in Parkinson’s disease: mobility, accidents, and sudden onset of sleep at the wheel.
C Meindorfner, Y Körner, JK Möller, K Stiasny-Kolster, WH Oertel and HP Krüger;
Commented by , 21 Sep 2005
Background
A considerable number of patients with PD are still in the working age and may rely on driving as part of their professional activity in addition to driving at leisure. Both motor impairment and sudden sleep attacks, which have been described in this patient population, may put these patients at increased risk of driving accidents.
Aim of the study
The objectives of this study were
- to assess accident rates and relation to sudden onset of sleep at the wheel in patients with PD
- to gather data on reasons for cessation of driving in patients with PD
Methods
A questionnaire was sent to 12,000 members of the German Parkinson Association. Completed data sets were available for 6,620 patients, and of those holding a driving license 361 were eventually interviewed by phone.
Patients provided data on experiencing sudden onset of sleep (SOS), on subjective disease severity with regard to mobility, and if they were involved or caused any road accidents.
Patients were classified into three groups:
- patients who reported to have experinced a SOS while driving after the onset of PD
- patients who reported an unintended sleep episode (SOS with prior sleepinesss) while driving after the onset of PD and
- patients who had an accident during the past 5 years, but never experienced SOS at the wheel after the onset of PD
SOS at the wheel and its consequences, current driving behavior, subjective disease severity and disease duration and inter-correlation between these parameters were evaluated using logistic regression.
Results
A total of 82% of the 6,620 patients held a driving license, and 60% of them still actively participated in the traffic. Of the patients holding a driving license, 15% had been involved in and 11% had caused at least one accident during the past 5 years.
The risk of causing accidents was significantly increased for patients who felt moderately impaired with regard to motor symptoms of PD, had an incrased Epworth Sleepiness Scale (ESS) score, and had experienced SOS while driving.
Sleep attacks at the wheel usually occurred in easy driving situations and resulted in fatigue-related accidents. Those who ceased driving had subjectively a more advanced disease severity, higher age, female gender, an increased ESS score, and a longer disease duration.
The authors concluded that in patients with PD SOS and daytime sleepiness are critical factors for traffic safety in addition to motor disability, real sleep attacks without any prior sleepiness were rare.
Professor Emre’s comments
Neurodegenerative diseases such as PD frequently affect basic as well as instrumental activites of daily living. Driving may be simply a leisure activity for some, but indispensable for other patients with PD, which affects a substantial number of patients in the economically productive age.
It has been known for another neurodegenerative disorder, Alzheimer’s disease (AD), with less motor, but more cognitive impairment that the risk of being involved in a car accident is significantly increased, especially beyond milder stages of cognitive impairment (ref. 1).
Impaired driving performance and an increased accident risk have also been previously reported for patients with PD (ref. 2; ref. 3). Although a control group of age-matched healthy individuals was missing, this study also revealed a substantial risk of driving accidents and demonstrated that in addition to motor disability daytime sleepiness and falling asleep at the wheel are significantly correlated with incrased risk of accidents.
Therefore it is important that physicians actively inquire with their patients and their families for the presence of daytime sleepiness and sleep attacks. It has been demonstrated for patients with dementia that clinicians can predict driving safety and identify potentially hazardous drivers to some extent, the accuracy was however judged to be insufficient compared to the results of a standardized road test (ref. 4).
Therefore it would be useful to develop standard measures to systemetically assess driving ability in patients with PD, especially in those with suspected impairment which may be due to motor dysfunction, cognitive deficits or daytime sleepiness including sleep attacks.
References
1. Dubinsky RM, Stein AC and Lyons K. Practice parameter: risk of driving and Alzheimer’s disease (an evidence-based review): report of the quality standards subcommittee of the American Academy of Neurology. Neurology 2000; 54 (12); 2205-2211
2. Borromei A, Caramelli R, Chieregatti G, et al. Ability and fitness to drive of Parkinson’s disease patients. Funct Neurol 1999; 14 (4); 227-234
3. Zesiewicz TA, Cimino CR, Malek AR, et al. Driving safety in Parkinson’s disease. Neurology 2002; 59 (11); 1787-1788
4. Ott BR, Anthony D, Papandonatos GD, et al. Clinician assessment of the driving competence of patients with dementia. Am Geriatr Soc 2005; 53 (5); 829-833