Diffusion weighted imaging reversibility in the brainstem following successful recanalization of acute basilar artery occlusion

Acute basilar artery occlusion (ABAO) is a devastating disease that can produce significant brainstem injury. Pretreatment diffusion weighted imaging (DWI) demonstrating extensive brainstem involvement has been shown to predict a poor outcome regardless of reperfusion. This case report describes a patient presenting with coma secondary to ABAO. MRI at presentation demonstrated significant DWI abnormality in the majority of the bilateral pons. The basilar artery was endovascularly recanalized 8 h after stroke onset, and the patient had a marked clinical recovery with no deficit at 3 months. Follow-up imaging revealed significant reversal of the pontine lesion. This finding of brainstem DWI reversibility cautions against the use of DWI to select ABAO patients for intra-arterial stroke therapy. The degree of apparent diffusion coefficient reduction on pretreatment MRI may not adequately identify which DWI abnormal brainstem tissue is potentially reversible.