Traumatic intracranial pseudoaneurysms of cortical middle cerebral artery and posterior cerebral artery branches presenting as subdural hematomas in elderly patients: A two-case report

BACKGROUND: Traumatic intracranial pseudoaneurysms (TIPAs) are exceedingly rare, representing <1% of all intracranial aneurysms, and are associated with high morbidity and mortality. They often remain occult on initial imaging, particularly when masked by concomitant subdural hematomas (SDHs).

CASE DESCRIPTION: We report two patients with traumatic pseudoaneurysms presenting as evolving SDHs. To the best of our knowledge, this is one of the few reports describing cortical middle cerebral artery (MCA) and posterior cerebral artery (PCA) pseudoaneurysms manifesting as SDHs in elderly patients. Case 1: An 86-year-old man presented with interhemispheric and tentorial SDHs. Serial computed tomography and magnetic resonance imaging (MRI) revealed progressive thickening and a 10 mm enhancing lesion. Cerebral angiography confirmed a 4.5 × 6.5 mm PCA pseudoaneurysm, which was successfully treated with Onyx embolization. He remained neurologically intact with stable follow-up imaging. Case 2 : An 83-year-old woman sustained a fall with left convexity, falcine, and tentorial subacute SDHs. MRI demonstrated a 7 mm focal contrast enhancement within the hematoma, and cerebral angiography during prophylactic middle meningeal artery embolization revealed a 5.8 × 5.6 mm distal MCA pseudoaneurysm. TIPA was treated with microsurgical clipping. She ultimately made a full recovery with near complete resolution of the SDH.

CONCLUSION: These cases illustrate that TIPAs may remain angiographically occult early and present only with an evolving SDH. Key diagnostic red flags include recurrent or tentorial SDH and focal cortical enhancement on MRI. Multidisciplinary management with timely angiographic evaluation and tailored surgical and/or endovascular therapy is essential to reduce the risk of catastrophic rebleeding.