Reduced and Delayed Cerebrovascular Reactivity in Patients with Parkinson's Disease

Abstract

Background Cerebrovascular dysfunction in Parkinson's disease (PD) is heterogeneous and may contribute to disease pathophysiology or progression. There is a need to understand the mechanisms by which cerebrovascular dysfunction is altered in participants with PD. Objectives The objective of this study is to test the hypothesis that participants with PD exhibit a significant reduction in the ability of the cerebral vessels to dilate in response to vasoactive challenges relative to healthy controls (HC). Methods The current study uses a vasodilatory challenge while participants undergo functional magnetic resonance imaging to quantify the amplitude and delay of cerebrovascular reactivity in participants with PD relative to age and sex‐matched HC. An analysis of covariance was used to evaluate differences in cerebrovascular reactivity amplitude and latency between PD participants and HC. Results A significant main effect of group was observed for whole‐brain cerebrovascular reactivity amplitude (F(1, 28) = 4.38, p = 0.046, Hedge's g = 0.73) and latency (F(1, 28) = 16.35, p < 0.001, Hedge's g = 1.42). Participants with PD exhibited reduced whole‐brain amplitude and increased latencies in cerebrovascular reactivity relative to HC. The evaluation of regional effects indicates that the largest effects were observed in the cuneus, precuneus, and parietal regions. Conclusions PD participants exhibited reduced and delayed cerebrovascular reactivity. This dysfunction may play an important role in chronic hypoxia, neuroinflammation, and protein aggregation, mechanisms that could lead to disease progression. Cerebrovascular reactivity may serve as an important biomarker and target for future interventions. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Progressive Cerebrovascular Reactivity Reduction Occurs in Parkinson's Disease: A Longitudinal Study

“…In the current study, using rsfMRI, reduced CVR was observed in certain cortex in PD, compared to HCs. Our in vivo findings supported that microvascular dysfunction might be involved in pathophysiology of PD, consistent with above‐mentioned studies in vitro and a previous study using transcranial Doppler in the patients with PD 33 and another study using BOLD fMRI with hypercapnia 18 . The temporal and occipital involvements were reported in PD, especially in PD with cognitive dysfunction 34,35 .…”

“…Although no significant differences were detected between the two groups, CVR in the corpus striatum was proved to reflect motor symptom severity. Another latest study found reduced and delayed whole brain CVR in PD patients compared with HC 18 . However, Al‐Bachari et al 19 demonstrated no statistically significant differences in CVR between PD and healthy controls (HCs).…”