Ruptured proximal lenticulostriate artery fusiform aneurysm presenting with subarachnoid hemorrhage: Case report

Lenticulostriate artery aneurysms are rare. When present, distal locations in and around the basal ganglia are more common and often present with intraparenchymal hemorrhage when ruptured. We present a very rare case of a ruptured proximal lenticulostriate fusiform aneurysm presenting with subarachnoid hemorrhage. CLINICAL PRESENTATION: We report the case of a 31 year-old healthy man who presented after the sudden onset of headache, nausea, and lethargy without neurological deficits. Cranial computed tomographic scanning demonstrated diffuse subarachnoid hemorrhage, and a cranial computed tomographic angiogram demonstrated a vascular irregularity on the superior surface of the left distal M1 trunk of the middle cerebral artery. A cerebral angiogram demonstrated a left proximal lenticulostriate fusiform aneurysm without evidence of moyamoya-like vessels or vasculitis. No other pathology or infectious etiology was noted. INTERVENTION: Endovascular therapy was deemed unsafe, and microsurgical exploration and intervention was the more favorable and safe approach. A standard left pterional craniotomy was performed and the afferent lenticulostriate vessel into the fusiform aneurysm was visualized. Temporary clips were applied to the proximal and distal M1 trunk and miniclips were applied across the afferent portion and fundus of the aneurysm, thus sacrificing the parent lenticulostriate artery. A postoperative computed tomographic scan demonstrated an area of hypodensity in the left basal ganglia. The patient's postoperative right facial and upper extremity weakness improved to normal several days after aneurysmal clipping. CONCLUSION: This is the first report of a ruptured proximal lenticulostriate artery fusiform aneurysm, which presented as subarachnoid hemorrhage in a healthy patient without an underlying vascular disease.