DECREASED DRIVING ABILITY IN PEOPLE WITH PARKINSONS-DISEASE

Background-Driving is a complex form of activity involving especially cognitive and psychomotor functions. These functions may be impaired b y Parkinson's disease. The relation between Parkinson's disease and dr iving ability is still obscure and clinicians have to make decisions c oncerning the driving ability of their patients based on insufficent i nformation. Until now no studies have compared different methods for e valuating the driving ability of patients with Parkinson's disease. Me thods-The driving ability of 20 patients with idiopathic Parkinson's d isease and 20 age and sex matched healthy control subjects was evaluat ed by a neurologist, psychologist, vocational rehabilitation counsello r, and driving instructor using a standard 10 point scale. The patient s and controls also evaluated their own driving ability. Cognitive and psychomotor laboratory tests and a structured on road driving test we re used for evaluating the subjects' driving ability. Results-The pati ents with Parkinson's disease performed worse than the controls bath i n the laboratory tests and in the driving test. There was a high corre lation between the laboratory tests and driving test both in the patie nt group and in the control group. Disease indices were not associated with the driving test. The neurologist overestimated the ability of p atients with Parkinson's disease to drive compared with the driving ab ility evaluated by the structured on road driving test and with the dr iving related laboratory tests. Patients themselves were not capable o f evaluating their own ability reliably. Conclusion-Driving ability is greatly decreased in patients with even mild to moderate Parkinson's disease. The evaluation of patients' driving ability is very difficult to carry out without psychological and psychomotor tests and/or a dri ving test.