A case of a giant intracranial aneurysm (GIA) with a blind sac on the left middle cerebral artery (MCA) accompanied by mural thrombosis is described. A 62-year-old male presented with headache and motor dysphasia. Magnetic resonance imaging and digital subtraction angiography revealed a GIA that arose from the proximal MCA. The M2 segment of the MCA was not visualized due to intramural thrombosis. The patient was treated with an extracranial-intracranial arterial bypass and trapping of the aneurysm. Literature relevant to the management of this rare lesion is reviewed and discussed.

Polycythemia vera (PV) is a myeloproliferative disorder characterized by clonal proliferation of hematopoietic stem cells leading to an accumulation of erythrocytes, leukocytes and platelets within the circulation. Thrombosis and hemorrhage are the most common serious complications of PV, and occur in 30-50% of patients. We report an unusual case of PV initially presenting with intraventricular hemorrhage, with concomitant ischemic heart disease.

Two male patients who presented with altered mental states and hemiparesis were treated by retrieval thrombectomy. The occlusion sites were M1 in both patients. During each thrombectomy, a self-expanding and fully retrievable Solitaire stent was partially deployed to cover the whole intra-arterial clot and then was retrieved slowly while occluding the internal cerebral artery with a balloon-guiding catheter. Complete recanalization (defined as thrombolysis of cerebral infarction grade 2b or 3) was achieved in both patients. The procedural time from groin puncture to recanalization was 17 min and 30 min, respectively. Immediate post-operative National Institutes of Health Stroke scores improved to 17 from 22 in one patient and to 19 from 24 in the other patient. There were no procedure-related complications including distal embolisms or post-operative intracranial hemorrhages. We suggest that this technique may be a simple, rapid, and safe thrombolytic method for acute ischemic stroke patients with large artery occlusions.

Cerebral angiography with contrast medium (CM) is a key method for diagnosis and interventional treatment of intracranial cerebral vascular lesions. Cerebral angiography causes few neurologic complications. There have been rare reports of complications related to disruption of the blood-brain barrier due to the administration of nonionic CM. We observed two patients with transient neurologic complications following cerebral angiography and coil embolization for unruptured aneurysm.

Objective: This study aimed to verify the validity and effectiveness of indirect bypass surgery as a treatment for Moyamoya disease. The development of post-surgical collateral circulation was investigated, and the clinical effectiveness of the surgery was confirmed. Methods: Of 45 patients (66 hemispheres) with Moyamoya disease, 28 (42 hemispheres) were followed by cerebral angiography for at least 6 months after surgery, between May 2002 and May 2009. There were eight men (13 hemispheres) and 20 women (29 hemispheres) with an average age of 24 $\pm$ 17.1 years (range, 2-62 years) at the time of diagnosis. The average follow-up period was 23 $\pm$ 18.6 months (range, 6-67 months). Indirect revascularization surgery was performed as encephaloduroarteriomyosynangiosis (EDAMS) in 39 cases, encephaloduroarteriosynangiosis (EDAS) in three cases, and bifrontal encephalogaleoperiosteal synangiosis (BEGPS) in 21 cases. The development of collateral circulation was assessed by cerebral angiography at least 6 months after surgery to evaluate the results of the indirect revascularization surgery. For the classification, good indicated collateral circulation of more than two-thirds of the middle cerebral artery distribution; $fair$ between one- and two-thirds; and $poor$ very weak or no collateral circulation. The development of collateral circulation was compared according to age, gender, clinical feature, surgical method, and Suzuki stage. Results: Cerebral infarction was the most frequent clinical feature at the time of incidence (27 cases; 64.4%), and Suzuki stage 3 was most common (15 cases; 35.7%). Based on cerebral angiography, 85.7% of patients showed good or fair development of collateral circulation, which was better among pediatric patients ($\leq$15-years-of-age) than adult patients (>15-years-of-age; p = 0.0344). Compared with EDAS, EDAMS tended to show better surgical results, but the difference was not statistically significant. Gender, clinical feature, or Suzuki stage did not influence the results. Among 21 patients in whom BEGPS was performed, 15 (71.4%) showed good or fair development of collateral circulation. Conclusion: Among the Moyamoya disease patients who received indirect bypass surgery, about 85% showed good or fair results, with collateral circulation involving more than one-third of the middle cerebral artery area. In addition to its effect in pediatric patients younger than 15-years-of-age, indirect bypass surgery also resulted in the development of collateral circulation in adults. EDAMS showed better effectiveness than EDAS as a surgical method. It is speculated that multiple, open arachnoid membranes stimulate the development of collateral circulation. One shortcoming of indirect bypass surgery for Moyamoya disease is that several months are required for the development of collateral circulation. One advantage is that it enables sufficient collateral circulation to develop in those who cannot endure direct bypass surgery. More effective results are expected with BEGPS.