[Consciousness Impairment and Left Hemiparesis due to Contrast Medium in the Coil Embolization of Unruptured Large Right Middle Cerebral Artery Aneurysm: A Case Report].

: Neurological deficits following coil embolization of anterior circulation aneurysms due to the toxicity of contrast medium are rare. Here, we describe a patient with mild consciousness impairment and left hemiparesis following coil embolization of a large right middle cerebral artery aneurysm without evidence of ischemia or hemorrhage, who recovered completely with conservative treatment. The patient's clinical course and radiological findings led us to conclude that the neurological deficits were due to the toxic effect of contrast medium used during the coil embolization.