Case Report: Cerebral air embolism following fluid–air exchange during pars plana vitrectomy: a rare but severe complication

Cerebral air embolism (CAE) is a rare but potentially life-threatening neurological emergency, typically caused by the inadvertent entry of exogenous air into the venous circulation and subsequent migration to the cerebral vasculature. It presents with abrupt onset and a prognosis that heavily depends on early recognition and prompt intervention. We report a case of CAE that occurred during pars plana vitrectomy (PPV) involving intraoperative fluid–air exchange. The patient experienced sudden ocular pain intraoperatively, followed shortly post-operatively by acute neurological symptoms including altered consciousness, ataxia, and slurred speech. Brain MRI using a standard stroke protocol, including DWI with b values of 0 and 1,000 s/mm 2 and ADC maps, revealed multiple acute infarcts in the bilateral frontal, parietal, and occipital lobes, thalamus, and corpus callosum. DWI demonstrated widespread hyperintensity with corresponding ADC reduction. Although no definite intravascular air artifacts were detected, the combination of intraoperative pressure fluctuations, a hypercoagulable state, and elevated levels of D-dimer and cardiac troponin I strongly supported the diagnosis of CAE with possible concomitant microembolism-induced ischemia. The patient received prompt multidisciplinary intensive care and exhibited marked neurological recovery with favorable prognosis. This case highlights the need for high clinical suspicion of CAE during procedures involving air infusion, abrupt pressure changes, or vascular injury risk. Emergent neuroimaging and multidisciplinary management are critical to minimizing neurological sequelae and ensuring patient safety.