Pseudohypoxic brain swelling after elective clipping of an unruptured anterior communicating artery aneurysm.

A case of pseudohypoxic brain swelling, a newly defined entity, is described. The patient experienced generalized seizures and did not awake initially after a seemingly uneventful elective craniotomy for clipping of an unruptured anterior communicating artery aneurysm. Neuroimaging findings demonstrated diffuse brain swelling, especially in the bilateral basal ganglia and thalami. The rarity of this postoperative complication is addressed and the pathogenesis discussed.