4D flow in Parkinson’s disease: cognitive decline corresponds with impaired circle of Willis haemodynamics

Motivation: The neurovascular changes associated with cognitive decline in Parkinson’s disease (PD) remain uncertain. Like Alzheimer’s disease, blood flow integrity may also play a significant role in maintaining cognitive function in PD. Goal(s): To understand the relationship between cognitive impairment and circle of Willis anatomy and haemodynamics in PD. Approach: 36 healthy controls and 81 individuals with PD completed 3T 4D flow MRI acquisition and an extensive neuropsychological battery. Results: The PD group showed 10% lower total cerebral blood flow (ml/min) and 7% lower flow velocity (cm/min) which were associated with poorer cognition. Impact: 4D flow MRI revealed hypoperfusion of the circle of Willis in Parkinson’s disease which corresponded with poorer cognition. These results support future targeting of vascular mechanisms to alleviate cognitive impairment in Parkinson’s disease.