DWI Reversibility in Acute Ischemic Stroke Due to Basilar Artery Occlusion Following Successful Recanalization

Diffusion Weighted Imaging (DWI) represents the infarct core in acute ischemic stroke. DWI reversibility is a phenomenon reported for the anterior circulation affecting small brain areas of the white matter. This study aims to define DWI reversibility in the posterior circulation after successful recanalization of basilar artery occlusion (BAO) and its influence on patient outcome.

This was a retrospective analysis of two tertiary stroke-centers analyzing stroke patients between January 2015 and December 2022. Inclusion criteria were available MRI before and after acute stroke treatment and successful BAO recanalization. Brain areas were defined as brainstem, cerebellum and supratentorial brain areas supplied by the posterior circulation. These areas were compared in univariate analysis. Secondarily, patient outcome was compared between patients with DWI reversibility and patients without in univariate analysis with good outcome as primary endpoint (mRS 90d 0 to 2).

In total, 5/28 of included patients (21.74%) showed DWI reversibility, which was exclusively found in the brainstem. The overall extent of brainstem infarction correlated better with patient outcome compared to cerebellar or supratentorial infarction (Spearman's ρ = 0.757; p < 0.001). Good outcome was more frequent in patients with DWI reversibility compared to those without (mRS 0-2, DWI+ n = 4, 80% vs. DWI- n = 6, 26%, p = 0.023).

DWI restriction reversibility was observed in the brainstem of acute stroke patients with BAO. In this study, patient outcome correlates stronger with the extent of brainstem infarction compared to cerebellar or supratentorial infarction.