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)

Stroke patients form a risk group as drivers due to their decreased cognitive and psychomotor abilities, and driving ability should always be evaluated after stroke. The results suggest that multidisciplinary neurological teams are able to evaluate the driving ability of stroke patients reliably. A careful evaluation of driving ability without a driving test requires assessment of cognitive and psychomotor functions critical in driving, which is not feasible for physicians without the support of a multidisciplinary team and/or traffic-related laboratory tests.

30 patients with a history of transient ischemic attacks (TIA) and 16 patients with cerebral infarcts were evaluated neuropsychologically 1–3 days before carotid endarterectomy, due to hemodynamically significant carotid artery stenosis, and again 2 weeks and 2 months after operation. Preoperatively, there were no differences between the groups, but postoperatively the neuropsychological outcome of the TIA patients was better than that of the infarction patients. Consequently, carotid endarterectomy patients cannot be studied as one group in neuropsychological examinations but various subgroups should be dealt with separately. In the TIA group 2 months after operation, the patients with left-sided operations had improved in verbal but not in visual tests, and the right-operated patients showed improvement also in visual tests. Therefore, the use of sum scores across neuropsychological tests is not preferable in the evaluation of the effects of carotid endarterectomy because after unilateral operation the cognitive improvement is greater in functions ipsilateral to the operation side.

The regional cerebral blood flow (rCBF), intial slope index (ISI), transfer time (th) and volume (rCBV) were measured simultaneously in 43 hospital patients using a 133Xe intravenous injection method and quantitative dynamic 99Tcm brain scintigraphy. The measurements were made with a gamma camera and the data processing interfaced with a small digital computer. The following mean values and standard deviations were obtained from 50 control hemispheres standardized to the age of 40 years: (formular): see article. Good agreement was found between the blood flow values determined from the intra-arterial and intravenous injection techniques.