Association of age-related white matter hyperintensity with brain atrophy and cognitive impairment in patients with Parkinson's disease

Abstract

Objective: To investigate the association of age-related white matter hyperintensity (WMH) with brain atrophy and cognitive impairment in patients with Parkinson's disease (PD). Methods: Consecutive samples of a prospective PD cohort with complete 3-dimensional magnetic resonance imaging in the Department of Movement Disorders in Beijing Tiantan Hospital, Capital Medical University, from October 2018 to August 2019 was retrospectively analyzed. Cognition was evaluated by Mini-Mental State Scale (MMSE) and Montreal Cognitive Assessment (MoCA). The severity of WMH was semi-quantitatively measured by Fazekas scale (0-6 points), and the mean cortical thickness and thalamus volume were calculated by FreeSurfer software. The demographic and disease characteristics, the severity of WMH, the mean cortical thickness and thalamus volume were respectively compared between PD patients with and without dementia. Moreover, univariate and multivariate generalized linear models were used to analyze the correlation of the severity of WMH with brain atrophy and MoCA. Results: A total of 225 patients with PD were included in the study, with a median age of 66 years old. Comparisons between groups suggested that patients with dementia were with severer WMH, older, and had lower levels of serum cholesterol and low-density lipoprotein and more reduced mean cortical thickness than those without dementia (all P<0.05), but no significant difference in the thalamus volume was found between the two groups. The generalized linear model showed that the cognitive impairment of PD patients was significantly correlated with WMH (β=-0.021, 95%CI:-0.040--0.002, P=0.032), but independent of age, cortical thickness, and levels of serum cholesterol and low-density lipoprotein. Conclusion: WMH may worsen PD cognitive impairment independent of brain atrophy. Clinical prevention and treatment of cerebral small vessel disease may have protective effects on cognitive function in patients with PD.