Ruptured distal anterior cerebral artery (A2) aneurysm presenting with simultaneous bilateral intraparenchymal hemorrhage and acute subdural hematoma: A case report and literature review.

Distal anterior cerebral artery (DACA) aneurysms are rare, representing a small fraction of intracranial vascular malformations. Their management is complex due to their deep interhemispheric location and often unfavorable morphology. We present an exceptionally rare case of a 56-year-old woman who suffered a rupture of a 5-mm A2-segment DACA aneurysm, leading to a unique combination of simultaneous bilateral frontal intraparenchymal hemorrhage and an acute subdural hematoma. This specific hemorrhagic pattern is significantly rarer than the typical subarachnoid hemorrhage and is often associated with high-pressure bleeding jets or arachnoid adhesions. The patient presented in a critical neurological state with rapidly progressing bilateral mydriasis. Following urgent decompressive craniectomy and microsurgical clipping, she achieved a favorable recovery. This case adds significant value to the literature by illustrating that DACA aneurysms should be considered in the differential diagnosis of nontraumatic bilateral frontal bleeding, and it demonstrates that even in the presence of severe multi-compartmental hemorrhage, prompt surgical intervention can lead to a positive long-term outcome.