CASE REPORT Report of two cases of a rare cause of subarachnoid hemorrhage including unusual presentation and an emerging and effective treatment option Eric MacKenzie Nyberg, 1 M Imran Chaudry, 1 Aquilla S Turk, 1 Alejandro M Spiotta, 1 David Fiorella, 2 Raymond D Turner 1 1 Department of Neurosciences and Radiology, Medical University of South Carolina, Charleston, South Carolina, USA 2 Department of Neurological Surgery, SUNY Stony Brook, University Medical Center, Stony Brook, New York, USA Correspondence to Dr R D Turner, Department of Neurosciences, Medical University of South Carolina, 96 Jonathan Lucas Street, Suite 428 CSB, Charleston, SC 29466, USA; turnerrd@musc.edu Received 12 April 2012 Revised 8 June 2012 Accepted 5 July 2012 Published Online First 28 July 2012 ABSTRACT Purpose To report two cases of a rare cause of subarachnoid hemorrhage (SAH), including unusual presentation and an emerging and effective treatment option. Case reports Ruptured basilar perforator artery aneurysm is a rare cause of SAH. Catheter angiography in the immediate post hemorrhage period may be unrevealing. We report two cases of ruptured basilar pontine perforator aneurysms. In one of these cases the perforator aneurysm was not apparent on the initial or the 1 week follow-up angiograms. Both patients returned for follow-up angiography 2 months later by which time aneurysmal filling and conspicuity had increased. Both patients were treated solely with two overlapping Neuroform stents. Follow-up angiograms demonstrated complete resolution of the aneurysms in both patients. Conclusions Rupture of aneurysms arising from basilar artery perforators is a rare cause of SAH and attention to this area should be part of an interventionist ’s search pattern. Aneurysms in this area may not be apparent in the immediate post rupture setting and delayed post hemorrhage angiography has a role in detecting this entity. Stent monotherapy may be effective in treating these lesions. INTRODUCTION Catheter angiography is currently the gold stand- ard for evaluating the cerebral vasculature and is essential in the diagnostic workup of non- traumatic subarachnoid hemorrhage (SAH). In a minority of cases, however, angiography performed in the days immediately following SAH may be unrevealing. The rate of angiography negative SAH has been reported to be as high as 17% in the recent literature. 12 The diagnostic yield of repeat catheter angiography in the following weeks and months is also uncertain. Out of 72 patients with angiogram negative SAH collected over a 5 year period, Almandoz et al found a 4.2% yield for a second angiogram performed at 7 days; the 43 patients in this series who underwent a third angiogram at 3 months still did not demonstrate an angiographic cause of SAH. 3 The yield of a third catheter angiogram in the setting of two previous negative catheter angio- grams for an aneurysm or other source of SAH is likely to be quite low. However, given the poten- tially devastating consequences of failure to detect a hemorrhagic and treatable lesion, patients at our institutions with two negative catheter angio- grams return 4–8 weeks after their initial presenta- tion for a third catheter angiogram before such a lesion is ruled out. Although the type of basilar perforator artery aneurysm described below is quite rare, several authors who have described this entity have found it subsequent to an initial nega- tive conventional angiogram. 4–6 CASE REPORTS Case No 1 A 40–50-year-old man presented with SAH. Catheter angiogram on admission demonstrated a tiny vascu- lar structure along the posterior wall of the basilar artery, although the significance of this finding was uncertain at the time. Treatment was initially sup- portive and the hospital course was uneventful. The patient was discharged with no neurologic deficits. Two months later, the patient returned for a third catheter angiogram at which point the aneurysm was significantly more conspicuous. The patient was subsequently loaded with aspirin and clopidogrel and returned for stent placement. Two overlapping 4×15 mm Neuroform stents (Stryker Neurovascular, Kalamazoo, Michigan, USA) were placed in the basilar artery across the perforator branch origin har- boring the aneurysm. Serial contrast enhanced MRI demonstrated a progressive decrease in size of the aneurysm over the following 7 weeks. Follow-up angiograms performed at 2 months and 14 months demonstrated complete resolution of the aneurysm without recurrence ( figure 1). Case No 2 A 60–70-year-old woman presented with SAH dis- tributed primarily around the brainstem. CT angio- gram performed on admission was negative for an aneurysm or other source of SAH. Catheter angiog- raphy performed on days 1 and 6 were likewise negative for aneurysm or other source of hemor- rhage. The hospital course was uneventful and the patient was discharged home with no neurologic deficits. The patient returned for follow-up angiog- raphy 9 weeks later, which demonstrated a 2–3 mm basilar artery perforator aneurysm. The patient was loaded with aspirin and clopidogrel and returned several days later for treatment with two overlapping Neuroform stents ( figure 2). Follow-up angiograms performed 1 and 4 months post stent demonstrated no filling and no recur- rence of the aneurysm. J NeuroIntervent Surg 2013;5:e30. doi:10.1136/neurintsurg-2012-010387 1 of 4 Hemorrhagic stroke