Acute subdural hematoma from ruptured middle cerebral artery aneurysm: A rare and critical analysis of 25 cases.

Background: An acute subdural hematoma (aSDH) is a rare presentation of a ruptured intracranial aneurysm with pathophysiology and prognosis poorly defined. According to literature, prognosis might be improved with prompt diagnosis, hematoma evacuation and aneurysm treatment. The objective is to specify pathophysiology, prognostic factors and management of this pathology.

Methods: We reported 23 cases of aSDH due to ruptured MCA aneurysm from literature revision and 2 cases from our center.

Results: Median age was 51 years and 48% (12/25) were females. At their arrival, 76% (19/25) presented decreased level of consciousness and 55.55% (10/18) neurological deficits. Aneurysmal location was left MCA in 57.14% (8/14) and MCA segments were M4 in 76.92% (10/13) and bifurcation in 23.07% (3/13), median aneurysmal size was 6 mm, median hematoma size was 10 mm, median midline shift was 9 mm, aneurysmal projection and MCA concavity were anterior in 100% (3/3), subarachnoid hemorrhage (SAH) was present in 52.17% (12/23). The treatment was surgery in 84% (21/25), endovascular in 12% (3/25) and in 20% (5/25) decompressive craniectomy (DC) was necessary. Glasgow Outcome Scale (GOS) was >3/favorable in 66.66% (16/24) and death in 16.66% (4/2).

Conclusions: Anterior MCA concavity and aneurysmal projection might be related with aSDH presentation in proximal MCA aneurysms. We should suspect aneurysm origin when there is no history or stigma of trauma, and CT shows disproportionately massive aSDH. Hematoma evacuation solves the compressive mechanism which is the main cause of neurological deterioration in pure aSDH cases, because of that, immediate hematoma evacuation could justify better outcome in these patients.