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.