Traumatic pseudoaneurysm of the superior cerebellar artery

Abstract

A 31-year-old man admitted to our hospital as the victim of aggression with an indeterminate object. At initial evaluation, he presented Glasgow Coma Scale score of 11, left anisocoria, without penetrating injury in head. Before performing computerized tomography scan, the patient’s level of consciousness worsened (Glasgow Coma Scale score 7). Skull computerized tomography scanning showed traumatic subarachnoid hemorrhage and hydrocephalus, with important ventricular blood, and a small cerebellar contusion (Fig. 1). External ventricular drainage with intracranial pressure monitoring was established. Because of the large amount of cisternal bleeding, we decided to perform a cerebral angiogram, that showed a pseudoaneurysm of the left superior cerebellar artery (SCA; Fig. 2). We performed an endovascular occlusion of the pseudoaneurysm (Fig. 3) without complications. In early follow-up, the patient developed shunt-dependent hydrocephalus. After final placement of a shunt, he was discharged for rehabilitation with Glasgow Outcome Scale score being 3. Traumatic intracranial aneurysms are rare, comprising less than 1% of all intracranial aneurysms. Less than 10% involve the posterior circulation. Aneurysms arising from the SCA are rarer and only six cases had been reported.1 Histologically, they are false aneurysms that contain none of the normal arterial layers but are lined by fibroconnective tissue surrounding a hole in the arterial wall.2 Penetrating wounds were responsible for 40% of the traumatic aneurysms located in posterior circulation.3 In the absence of a fracture or penetrating wound, like in our patient, some traumatic aneurysms have been observed on arteries in relation to the edge of rigid meningeal structures.1 We believe that in our case, the head trauma produced a rotary movement of the brain within the skull, tearing an arterial branch of the SCA that passes through the perimesencephalic cistern. DISCLOSURE The authors declare no conflicts of interest.