Visual Evoked Potentials in Parkinson's Disease and Multiple Lacunar Infarction

Abstract

To clarify the underlying mechanism of abnormality in visual evoked potentials (VEPs) in Parkinson's disease (PD), pattern reversal VEPs were examined in PD as compared with multiple cerebral infarction in the subcortical regions (multiple lacunar infarction: MCI). In particular, the relationship between the VEPs and dementia was investigated. The patients with PD and MCI were divided into 4 groups; PD without dementia (nD‐PD: n=20), PD with dementia (D‐PD: n=13), MCI without dementia (nD‐MCI: n=18), and MCI with dementia (D‐MCI: n=12). Sixteen normal subjects were employed as control. There was no significant difference in age among the 5 groups. The D‐PD patients showed significantly longer P100 latencies compared to the other 4 groups (p<0.05). In the PD patients, the P100 latencies were significantly correlated with illness duration (p<0.05). A significant negative correlation was found between the P100 latencies and scores on Mini‐Mental State Examination (MMSE) in the PD patients (p<0.01). The MMSE score did not correlate with illness duration (p>0.1). The MCI patients showed no significant difference in the VEPs findings compared to the control subjects. These findings suggest that the abnormal VEPs in the D‐PD patients may be related to the dementing process and that subcortical lesions make a little contribution to the VEPs delay.