2025 American Academy of Neurology Abstract Website

Objective:

To conduct a systematic review and meta-analysis evaluating the predictive value of impaired cerebrovascular reactivity (CVR) for incident stroke in patients with intracranial atherosclerosis (ICAS) or moyamoya disease.

Background:

CVR reflects the brain's ability to increase blood flow in response to vasodilatory stimuli. While impaired CVR is associated with an increased risk of stroke in asymptomatic carotid stenosis, its relationship with incident stroke in ICAS and moyamoya remains unclear.

Design/Methods:

Systematic search of PubMed and Embase was conducted from inception to September 2024. Eligible studies compared impaired and preserved CVR in ICAS or moyamoya. The primary outcome was incident stroke. Pooled relative risks (RR) with 95% confidence intervals (CI) were calculated using a random-effects model, and forest plots were constructed.

Results:

Ten observational studies involving 606 patients were included (365 with ICAS, 241 with moyamoya). Impaired CVR was observed in 46% of the total population, with a mean follow-up of 27.6 months (IQR 20.7–37.0). The median age was 54.3 years (range 5–67) for the impaired CVR group and 55.4 years (range 7–68) for controls. Hypertension was present in 48% of both groups, and 58% of the impaired CVR group had a history of stroke compared to 49% of controls. Surgical intervention was performed in 41% of the impaired CVR group and 51% of the control group. The incidence of ischemic stroke was 30.0% (85/281) in the impaired CVR group versus 14.2% (46/325) in controls (RR 2.95; 95% CI 1.45-6.00; P<0.005). Subgroup analysis of studies that included only ICAS showed an RR of 3.31 (95% CI 1.21-9.07; P<0.05), and studies that included only moyamoya showed an RR of 1.63 (95% CI 0.79-3.33; P=0.19).

Conclusions:

Impaired CVR is associated with incident stroke in patients with ICAS and moyamoya, underscoring the importance of CVR testing in risk stratification and management of these patients.