Decreased driving ability in people with Parkinson's disease

Abstract

Background-Driving is a complex form of activity involving especially cognitive and psychomotor functions. These functions may be impaired by Parkinson's disease. The relation between Parkinson's disease and driving ability is still obscure and clinicians have to make decisions concerning the driving ability of their patients based on insuYcent information. Until now no studies have compared diVerent methods for evaluating the driving ability of patients with Parkinson's disease. Methods-The driving ability of 20 patients with idiopathic Parkinson's disease and 20 age and sex matched healthy control subjects was evaluated by a neurologist, psychologist, vocational rehabilitation counsellor, and driving instructor using a standard 10 point scale. The patients and controls also evaluated their own driving ability. Cognitive and psychomotor laboratory tests and a structured on road driving test were used for evaluating the subjects' driving ability. Results-The patients with Parkinson's disease performed worse than the controls both in the laboratory tests and in the driving test. There was a high correlation between the laboratory tests and driving test both in the patient group and in the control group. Disease indices were not associated with the driving test. The neurologist overestimated the ability of patients with Parkinson's disease to drive compared with the driving ability evaluated by the structured on road driving test and with the driving related laboratory tests. Patients themselves were not capable of 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 diYcult to carry out without psychological and psychomotor tests and/or a driving test. (J Neurol Neurosurg Psychiatry 1998;64:325-330)

Neuropsychological deficits associated with driving performance in Parkinson's and Alzheimer's disease

“…Consistent with these latter findings, Madeley et al (1990) found a correlation between PD severity on Webster's rating scale (a 10 item scale of Parkinsonian motor symptoms) and simulated driving reaction time and steering accuracy, and Radford et al (2004) found that the Webster's rating scale, but not cognitive measures, differentiated between safe and unsafe driving on a road test. On the other hand, two more recent studies found that (1) on-road driving performance in PD patients was related to visual processing speed, levodopa dosage, and age, rather than to the Webster's scale (Heikkila et al, 1998); and (2) that although PD drivers were less safe compared to controls on a road test, standard clinical disease markers (i.e., H&Y, UPDRS) did not reliably predict driving performance, suggesting that other measures are necessary to predict driving safety in PD (Wood et al, 2005). In summary, although several studies have identified factors contributing to driving performance in PD patients, the relative contribution of motor and cognitive deficits to unsafe driving in this population has yet to be resolved.…”

“…Individuals with Parkinson's disease (PD) may be particularly at increased risk of driving impairment due not only to progressive deterioration in motor functions essential to driving, but also to progressive deterioration in driving-related cognitive functions such as attention, executive control, memory encoding and retrieval, visuoperception, reaction time, and speed of information processing (Heikkila et al, 1998).…”

Neurologic Conditions: Assessing Medical Fitness to Drive

“…There is a poor correlation between patient questionnaires and disease severity scales in determining medical fitness to drive. 64,65 The cognitive impairment seen in patients with Parkinson's disease includes short term working memory, non-verbal recognition memory, attention and visuospatial deficits. 66,67 Slowness in cognitive functions including processing, choice reaction times, visual perception and memory have been identified as key factors that affect driving in patients with Parkinson's disease.…”

“…66,67 Slowness in cognitive functions including processing, choice reaction times, visual perception and memory have been identified as key factors that affect driving in patients with Parkinson's disease. 64 It is important to assess both the motor and cognitive function when performing a medical assessment to determine fitness to drive. Patients with Parkinson's disease may show evidence of reduced power, speed and accuracy of movement.…”

Performance in normal subjects on a novel battery of driving-related sensory-motor and cognitive tests

“…Thus, six cognitive tests were developed and added to form SMCTests: Complex Attention, Visual Search, Decision-Making, Impulse Control, Planning, and Divided Attention (Innes et al, 2007). Following an evaluation of the literature, deficits in these six cognitive functions were identified as those most frequently identified subjectively during on-road assessments of subjects with brain disorders (e.g., Heikkilä, Turkka, Korpelainen, Kallanranta, & Summala, 1998;Korteling, 1990;Staplin, comprised 20 trials of static images, each containing 70 road-sign stimuli ( Figure 1E). Each screen was presented for a maximum of 10 sec.…”