Prevalence of radiological and clinical cerebrovascular disease in idiopathic Parkinson's disease.

Comorbid cerebrovascular disease (CVD) can occur in idiopathic Parkinson's disease (IPD) but its reported prevalence varies considerably. CVD may alter the clinical presentation, course and prognosis in IPD. We aimed to determine the prevalence of radiological and clinical CVD in a neurology clinic IPD population. We undertook a retrospective case-control study of neurology clinic patients with IPD for whom cerebral imaging was available, and excluding probable vascular parkinsonism. IPD diagnosis was validated against UK PDS brain bank criteria. Age and sex-matched controls were identified from patients attending neurology clinics with headache. The presence of radiological cerebrovascular disease, symptomatic CVD (stroke and TIA), and CVD risk factors was recorded for cases and controls. Radiological findings were validated by an experienced consultant neuroradiologist using a structured proforma. Eighty-five cases and 85 controls were studied, based on the number of cases for whom brain imaging existed (CT in 50, MRI in 35) and the number of cases for whom suitable controls could be identified. Indications for brain imaging amongst cases were varied. Cases and controls comprised 55(65%) males, mean (± SD) age (years) 67.4 ± 10.1 (cases), 66.6 ± 9.9 (controls). Radiological CVD was significantly commoner amongst cases (39%) than controls (22%) (p=0.02, chi-square; odds ratio 2.2, 95% CI: 1.1-4.6). Cases also had significantly more symptomatic CVD, but not CVD risk factors, than controls. Our findings suggest a higher prevalence of radiological and clinical CVD in patients with IPD compared to controls.