Periventricular White Matter Hyperintensities Burden and Cognitive Impairment in Early Parkinson’s Disease

OBJECTIVE: This study quantified the total brain and periventricular white matter hyperintensities (WMHs) burdens in patients with early Parkinson disease (PD) and explored their associations with cardiovascular risk factors and cognitive performance. METHODS: 175 non-demented early PD patients who had undergone baseline brain MRI were included. Comprehensive neurocognitive testing was conducted to identify PD mild cognitive impairment (PD-MCI) and to evaluate performances in individual cognitive domains. Cardiovascular risk was expressed as modified Framingham 10-year cardiovascular risk score (mFRS). RESULTS: 53.7% of this early PD cohort fulfilled the diagnostic criteria for PD-MCI. Increase in mFRS was significantly associated with increased in the total brain WMHs (p=0.015) and the periventricular WMHs (p=0.040) burden, independent of age and gender. Periventricular WMHs burden was significantly associated with PD-MCI (p=0.046) in early PD, independent of cardiovascular risk factors. Patients in the 5(th) quintile of periventricular WMHs burden were 8.6 times more likely to have PD-MCI compared with patients in the 1(st) quintile of periventricular WMHs burden (p=0.004). On the other hand, total brain WMHs burden was not associated with PD-MCI (p=0.158). In individual cognitive domains, heavier periventricular WMHs burden was associated with worse executive function and visuospatial function independent of cardiovascular risk factors. CONCLUSION: Periventricular WMHs is a useful imaging biomarker for cognitive impairment in early PD. Cardiovascular risk factors, although associated with periventricular WMHs, were unable to fully explain the association between periventricular WMHs and cognitive impairment in early PD.