Abstract WP251: Neuroimaging features of cerebral air embolism: a matched case-control study

Introduction: Cerebral air embolism (CAE) is a rare but treatable cause of ischemic stroke. Prompt diagnosis is critical to expedite appropriate treatment. We aimed to better define the imaging features of CAE by comparing MRI features in patients with confirmed CAE to those in cardioembolic stroke due to atrial fibrillation (AF). Methods: In a retrospective, matched case-control study, CAE cases from 2012-2023 were matched 1:2 by presenting NIHSS to control patients who had stroke due to AF and were not treated with thrombolytics or thrombectomy. MRIs were reviewed by a neuroradiologist blinded to group. The primary outcome was presence of pre-specified neuroimaging features on MRI, which included number of infarctions, diffusion restriction pattern, location, and laterality. Results: Fourteen patients with stroke due to CAE (median age 61, 64% female, median NIHSS 12) and 28 controls with stroke due to AF (median age 81, 43% female, median NIHSS 12) were included. The predominant infarct topography in CAE patients was gyriform in 86%, punctate in 7%, and wedge-shaped in 7%, whereas in patients with stroke due to AF the predominant infarct topography was wedge-shaped in 71%, punctate in 18%, and gyriform in 11% (p