Olfactory function distinguishes vascular parkinsonism from Parkinson's disease.

OBJECTIVE To compare olfactory function in vascular parkinsonism and Parkinson's disease diagnosed according to published clinical diagnostic criteria. METHODS The University of Pennsylvania smell identification test (UPSIT) was carried out in 14 patients with vascular parkinsonism, 18 with Parkinson's disease, and 27 normal controls matched for age, sex, and smoking status. RESULTS UPSIT scores in vascular parkinsonism (mean 26.1, 95% confidence interval, 23.1 to 29.0) were significantly better than in Parkinson's disease (mean 17.1 (14.5 to 19.7)) (p<0.0001), and did not differ from the healthy controls (mean 27.6 (25.8 to 29.4)) (p = 0.32). CONCLUSIONS Testing olfactory function may be helpful in differentiating vascular parkinsonism from Parkinson's disease.