A Case of Rapid Malignant Brain Swelling Subacutely After Reperfusion Therapy for Internal Carotid Artery Occlusion

Background Severe complications after reperfusion therapy for acute major vessel occlusion are not well described. We present an extremely rare case of a patient with rapid malignant brain swelling subacutely after acute ischemic stroke. Case Description An 84-year-old man underwent reperfusion therapy for acute left internal carotid artery occlusion; complete reperfusion was achieved. Although magnetic resonance imaging on postoperative day 1 revealed a small hemorrhagic infarction and subarachnoid hemorrhage unrelated to a left middle cerebral artery aneurysm in the left frontal lobe, neurologic deficits resolved completely. On postoperative day 5, the patient developed a fever and sudden disorder of consciousness with right hemiparesis. Urosepsis was diagnosed, and computed tomography revealed massive hemorrhagic infarction in the left frontal lobe and diffuse subarachnoid hemorrhage. Emergent hematoma evacuation and clipping were performed. Although the aneurysm was unruptured, brain swelling was severe despite a patent middle cerebral artery. Computed tomography performed immediately postoperatively (within 6 hours after preoperative computed tomography) showed severe left brain swelling with midline shift. The patient died on postoperative day 15. Conclusions This case has similarities to both second-impact syndrome after head trauma and perfusion breakthrough phenomenon. Initial ischemic damage following reperfusion therapy and damage secondary to sepsis and subarachnoid hemorrhage may have led to rapid malignant brain swelling in this patient. Careful management is important for patients receiving reperfusion therapy.