SUMMARY: Lenticulostriate aneurysms are rare and usually present with intracranial hemorrhage, limiting understanding of their natural course. We describe an unusual case of an unruptured rapidly growing distal LSA aneurysm in the setting of Moyamoya disease, successfully embolized with n-BCA following functional neurologic testing with amobarbital.ABBREVIATIONS: n-BCA ϭ n-butyl cyanoacrylate; MCA ϭ middle cerebral artery; ACA ϭ anterior cerebral artery; LSA ϭ lenticulostriate artery; DSA ϭ digital subtraction angiography R eports of LSA aneurysms are rare in the literature, numbering in the low 20s, with most cases diagnosed following intracranial hemorrhage due to rupture. [1][2][3][4][5] The natural history of these aneurysms is, therefore, largely uncertain. Predisposing factors include hypertension, arteriovenous malformation, infection, systemic lupus erythematosus, and Moyamoya disease. 4,5 The inherent difficulty in surgical treatment of these aneurysms, due to deep location, small size, and sometimes unfavorable morphology, is compounded in the setting of Moyamoya disease by vessel hemodynamic fragility.2,6-8 We discuss the utility of functional testing with amobarbital (Amytal) before endovascular embolization with n-BCA of an unruptured distal LSA aneurysm in the setting of Moyamoya disease.
Case ReportA 35-year-old woman with Moyamoya disease and a history of 2 ruptured aneurysms was referred for follow-up. Physical examination demonstrated mildly decreased strength on the left, decreased bilateral upper quadrant peripheral vision and right-sided hearing loss, and slightly unsteady gait. Reflexes and sensory examination findings were normal. Mental status examination demonstrated normal higher cortical and language function. The findings of the remainder of her physical examination and medical history were unremarkable.CT angiography demonstrated a 3-mm right distal LSA aneurysm and a Moyamoya vascular pattern, with numerous small-vessel collaterals supplying the MCA and ACA territories bilaterally. A right frontal pericallosal artery branch aneurysm clip was present. Conventional angiography 1 month later again demonstrated a right LSA aneurysm, now measuring 4.2 ϫ 3.9 ϫ 3.8 mm with a 1.8-mm neck, and collateral supply to a posterior frontal MCA branch. She was referred for endovascular treatment 10 days later.A 6F Guider catheter (Boston Scientific, Fremont, California) was positioned in the distal right internal carotid artery, through which an Excelsior SL-10 microcatheter (Target Therapeutics/Boston Scientific, Fremont, California) was advanced over a Synchro-10 microguidewire (Boston Scientific, Natick, Massachusetts) and positioned proximal to the aneurysm within the involved LSA. Superselective contrast injection demonstrated a 4.4-mm LSA aneurysm, retrograde filling of a dilated right posterior frontal MCA branch collateral from the aneurysm, and faint basal ganglia blush (Fig 1A). We administered 25 mg of Amytal via the microcatheter; subsequent neurologic examination demonstrated left faci...