Cerebral atherosclerosis in Parkinsonian patients.

Cerebral atherosclerosis has been previously postulated as a possible etiology for Parkinsonism. Epidemiological studies, however, have suggested a relatively low incidence of ischemic strokes in Parkinsonian patients. The aim of this study was to evaluate the prevalence of extra- and intracranial atherosclerosis in these patients. We performed carotid duplex studies and transcranial Doppler (TCD) examinations in 50 patients with idiopathic Parkinson's disease and in 50 healthy control subjects. The carotid duplex scanning results revealed fewer Parkinsonian patients with stenotic lesions (30% versus 38% in the control group; p=0.4). The TCD results demonstrated lower peak flow velocities in the Parkinsonian group versus the control group, and these differences were statistically significant in the basilar, vertebral and right middle cerebral arteries (p=0.03, 0.001 and 0.04, respectively). The carotid duplex scanning results could not provide a potential explanation for the relatively low occurrence of stroke in Parkinsonian patients, because most strokes are related to carotid atherosclerotic lesions while the TCD results might reflect a diminished blood supply secondary to a decline in tissue metabolism.