ABSTRACT
BACKGROUND: The cause of dementia in Parkinson's disease (PD) remains incompletely understood. Cerebrovascular lesions (CVLs) are frequently found in the aging brain and may coexist with PD pathology. We hypothesized that lacunar infarction, which is one type of CVL, impacts on cognitive decline in patients with PD. METHODS: The Mini Mental Status Examination (MMSE) and Clinical Dementia Rating (CDR) tools were applied to PD patients with lacunar infarction (<1.5 cm on brain MRI; PD-S) and PD patients with normal brain MRI (PD-NS). RESULTS: Totals of 19 PD-S patients (9 males and 10 females) and 59 PD-NS patients (16 males and 43 females) took part in this study. Univariate analysis revealed that the gender distribution did not differ between the PD-S and PD-NS groups (p=0.1731), whereas age did differ significantly [79.1+/-5.0 years vs 73.0+/-7.8 years (mean+/-SD), respectively; p=0.0002]. There was no difference between the PD-S and PD-NS patients in either PD disease duration (6.9+/-3.2 vs 5.6+/-3.8 years, respectively; p=0.1790) or education duration (5.3+/-5.4 vs 6.4+/-5.3 years, respectively; p=0.4168). After adjustment for age in ANCOVA analysis, the MMSE score was significantly lower (p=0.0128) and the CDR score was significantly higher (p=0.0426) in the PD-S group than in the PD-NS group. Ten of the PD-S patients had a single lesion. The lacunar infarctions appeared in various locations in these patients, but they were most common in the basal ganglia, thalamus, and periventricular white matter. CONCLUSIONS: Lacunar infarction appears to be associated with cognitive decline in patients with PD even after adjustment for age. Analysis of larger age-matched cases for PD-S and PD-NS is required in order to validate these results.