Neuroimaging Features of Cerebral Air Embolism: A Matched Case-Control Study

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Cerebral air embolism (CAE) is a rare but treatable cause of ischemic stroke.
• Distinguishing CAE from other stroke types, like those from atrial fibrillation (AF), is clinically challenging but crucial for effective treatment.
• Accurate diagnosis of CAE is critical for initiating appropriate and timely interventions.

Purpose of the Study:

• To define the characteristic neuroimaging features of cerebral air embolism (CAE) on MRI.
• To compare MRI findings in patients with CAE to those with cardioembolic stroke due to atrial fibrillation (AF).
• To identify imaging markers that can help differentiate CAE from AF-related stroke.

Main Methods:

• A retrospective, matched case-control study was conducted.
• CAE cases (2012-2023) were matched 1:2 with control patients experiencing stroke due to AF, excluding those treated with thrombolytics or thrombectomy.
• A neuroradiologist, blinded to group allocation, reviewed all MRIs to identify pre-specified neuroimaging features.

Main Results:

• Gyriform infarction patterns were predominant in CAE (86%) compared to AF stroke (11%) (p<0.001).
• CAE patients more frequently presented with multiple (93% vs. 50%) and bilateral (79% vs. 43%) infarctions.
• Cortical borderzone involvement was significantly more common in CAE (86%) than in AF stroke (25%) (p<0.001).

Conclusions:

• Cerebral air embolism (CAE) exhibits characteristic gyriform infarction patterns on MRI, differentiating it from typical cardioembolic stroke.
• The constellation of gyriform infarction, cortical borderzone predilection, and multifocal infarctions strongly suggests CAE.
• Timely identification of CAE, facilitated by recognizing these distinct imaging findings, is critical for managing this uncommon but serious condition.