Stroke due to basilar artery occlusion (BAO) carries poor outcomes despite advancements in endovascular therapy (EVT). Predictors of recovery remain underexplored. This study evaluates clinical and imaging predictors of outcomes following EVT, including a Critical Area Diffusion Score (CADS), assessing infarct location and extent in critical brainstem regions on post-EVT MRI.

This retrospective study analyzed 48 BAO patients treated with EVT at a provincial stroke center (2015–2021). Patients were categorized by outcomes (favorable: modified Rankin Scale [mRS] 0–3; unfavorable: mRS 4–6). Clinical, demographic and imaging data – age, baseline National Institutes of Health Stroke Scale (NIHSS), reperfusion success (thrombolysis in cerebral infarction [TICI] 2b–3) and post-EVT CADS from diffusion-weighted MRI – were assessed using univariate and multivariate logistic regression.

Patients with favorable outcomes were younger (median 64.0 vs. 73.0 years, p = 0.031), had lower NIHSS scores at presentation (median 8 vs. 16, p = 0.018) and achieved higher successful reperfusion rates (81.0% vs. 48.1%, p = 0.020). CADS ≤ 3 was linked to better outcomes (median mRS 3 vs. 5, p = 0.026) and higher odds of recovery in univariate analysis (OR = 10.89, p = 0.038). However, in multivariate analysis, CADS was not an independent predictor, with successful reperfusion (OR = 18.8, p = 0.044) as the strongest factor.

Age, NIHSS scores and successful reperfusion predict recovery in BAO patients undergoing EVT. Although CADS ≤ 3 is linked to favorable outcomes, it is not independently predictive. CADS holds promise as a prognostic tool, but its utility should be considered alongside clinical markers to enhance outcome prediction in BAO.