Electrophysiological differences between Parkinson's disease and vascular parkinsonism

Short-latency somatosensory evoked potentials (SSEPs) and brainstem auditory evoked potentials (BAEPs) were recorded in 30 patients with Parkinson's disease (mean age 66.3 years), 17 patients with vascular parkinsonism (mean age 70.5 years) and 22 normal subjects (mean age 66.7 years). In patients with vascular parkinsonism, the interpeak latencies between N13 and N20(CCTs) were significantly longer than those of patients with Parkinson's disease and normal subjects (p less than 0.005 and p less than 0.001, respectively). Patients with Parkinson's disease and normal subjects did not show any significant differences with regard to CCT. The significant differences between left and right CCT were revealed between patients with vascular parkinsonism and patients with Parkinson's disease or normal subjects (p less than 0.001 and p less than 0.001, respectively). Patients with vascular parkinsonism disclosed significant prolongation of interpeak latencies between waves I and V (I-V IPLs) compared to patients with Parkinson's disease and normal subjects (p less than 0.005 and p less than 0.001, respectively). Furthermore, the I-V IPLs in patients with Parkinson's disease were significantly longer than those of the normal subjects (p less than 0.01). The mean left-right differences of I-V IPLs in patients with vascular parkinsonism were longer than those of the other two groups. Present results indicate that there were some differences between Parkinson's disease and vascular parkinsonism from the electrophysiological aspects and suggest that assessments of SSEPs and BAEPs may be helpful in differentiating Parkinson's disease from vascular parkinsonism.