Cortical Infarction following Cardiosurgical Procedures – Air Embolism as a Probable Cause

Background:Focal neurological deficits following cardiopulmonary bypass surgery are usually thought to be the result of embolic stroke. Computed tomography (CT) is sometimes negative although severe deficits persist. Objectives: To describe a syndrome consisting of reduced postoperative vigilance, frequent epileptic seizures and focal neurological deficits in the presence of an apparently normal CT scan and often isolated cortical infarction on magnetic resonance imaging (MRI). Methods: We retrospectively collected data on all patients fulfilling the above-mentioned criteria, seen for neurological examination by the consultant between 2002 and 2006 in our heart center. Results: We found 39 patients, nearly all of whom had cortical hyperintense lesions on diffusion-weighted MRI in the right hemisphere with corresponding left-sided hemiparesis. Early seizures occurred in 31 patients. Clinical outcome was heterogeneous. Conclusions: Predominance of right hemisphere involvement and lesion pattern in MRI make air embolism the most probable cause for this postoperative syndrome.