subarachnoid Hyperdensity Following aneurysm Embolization in Renal Failure

Reprint requests to: Dr. Wei-Che Lin Department of Diagnostic Radiology, Chang Gung Memorial Hospital Kaohsiung Medical Center, Chang Gung University College of Medicine. No. 123, Ta Pei Road, Niao-Sung, Kaohsiung 83305, Taiwan, R.O.C. Po s t p r o c e d u r a l s e i z u r e w i t h i m p a i r e d consciousness and asymmetric subarachnoid hyperattenuations on computed tomography (CT) scans suggests periprocedural perforation of an aneurysm or contrast material–induced encephalopathy (CMIE). We now report the case of a 59 year-old woman with a history of end-stage renal disease and multiple intracranial aneurysms who underwent embolization with Guglielmi detachable coils. Fourteen hours after the intervention, the patient had a general seizure, with subsequent impairment of consciousness. Non-enhanced CT scans revealed diffuse subarachnoid hyperattenuation, more prominent in the left frontoparietal region. The patient received emergency hemodialysis. Post-dialysis CT demonstrated complete resolution of the hyperattenuation. In patients with end-stage renal disease, early post-embolization hemodialysis is necessary to avoid contrast material–induced encephalopathy and to clarify the potentially confusing complication of procedural rebleeding. When an episode of seizure occurs after GDC embolizat ion with subarachnoid hyperat tenuations on CT scans, it is important to differentiate aneurysmal rupture or encephalopathy induced by contrast mater ial because that management and prognosis are significantly different between those diagnoses. Here we describe an educational case with cont rast medium-induced encephalopathy (CMIE).