Amyloid related cerebral microbleed and plasma Aβ40 are associated with cognitive decline in Parkinson's disease

Area of Science:

• Neurology
• Neuroimaging
• Biomarkers

Background:

• Cerebral microbleeds (MBs) are associated with cognitive impairment.
• Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor and cognitive symptoms.

Purpose of the Study:

• To investigate the association between cerebral microbleeds (MBs) and cognitive or motor decline in Parkinson's disease (PD) patients.
• To explore the relationship between MBs, cognitive status (PD with dementia - PDD), and motor severity in PD.

Main Methods:

• 135 PD patients and 34 healthy controls underwent brain MRI and plasma biomarker assays (tau, Aβ42, Aβ40, α-synuclein).
• Parkinson's disease dementia (PDD) was defined by Mini-Mental State Examination (MMSE) score < 26.
• Multivariate logistic regression models were used to analyze the association between MBs and disease severity, adjusting for confounders.

Main Results:

• PD patients showed a higher prevalence of lobar MBs compared to controls (20.7% vs. 3.3%).
• PDD patients exhibited more lobar MBs, white matter hyperintensity, and reduced hippocampal volume than PD patients with normal cognition.
• Lobar MBs (OR=2.83) and severe white matter hyperintensity (OR=3.29) were independently associated with PDD. Plasma Aβ40 levels correlated with MMSE scores.

Conclusions:

• Lobar cerebral microbleeds (MBs) are more prevalent in Parkinson's disease (PD) patients, particularly those with dementia (PDD).
• Reduced hippocampal volume and lobar MBs are significant indicators of PDD.
• Plasma Aβ40 levels may serve as a potential biomarker for cognitive function in PD.