Aneurysms located at the distal portion of the posterior inferior cerebellar artery (PICA) are rare, and their clinical features are not fully understood. We report the clinical features and management of 30 distal PICA aneurysms in 28 patients treated during the past decade at Kagoshima University Hospital and affiliated hospitals. Our series includes 20 women and eight men. Of their 30 aneurysms, 24 were ruptured, and six were unruptured; there were 27 saccular and two fusiform aneurysms; one was dissecting. Their location was at the anterior-medullary (n = 4), lateral-medullary (n = 9), tonsillomedullary (n = 7), telovelotonsillar (n = 6), and cortical (n = 4) segment of the PICA. In 18 patients, angiographic features suggested hemodynamic stress including an absent contralateral PICA or ipsilateral anterior inferior cerebellar artery, termination of the vertebral artery (VA) at the PICA, and hyperplasia or occlusion of the contralateral VA. As three patients died before surgery, 27 aneurysms in 25 patients were surgically treated. Of these, 6 were unruptured aneurysms; 20 were clipped via midline or lateral suboccipital craniotomy, and 5 were embolized with Guglielmi coils; in one, the PICA flow was reconstructed by OA-PICA anastomosis, and in the other one, the PICA was resected. Of the 25 surgically treated patients, 22 (88%) had good outcomes. The predominant contributor to the development of distal PICA aneurysms is thought to be increased hemodynamic stress attributable to anomalies in the PICA and related posterior circulation. Both direct clipping and coil embolization yielded favorable outcomes in our series. However, considering the difficulties that may be encountered at direct clipping in the acute stage and the availability of advanced techniques and instrumentation, aneurysmal coiling is now the first option to address these aneurysms.

The incidence and characteristics of microbleeds in hemodialysis (HD) patients were investigated to elucidate the clinical significance with T 2 *-weighted gradient-echo magnetic resonance (MR) imaging. The 57 patients with chronic renal failure maintained by HD had no previous history of stroke. The control group consisted of 53 patients without previous history of stroke or chronic renal failure. The incidence and the number of microbleeds were assessed in the HD and control groups. The findings of microbleeds with T 2 *-weighted gradient-echo MR imaging were compared with those of T 1 -and T 2 -weighted MR imaging in HD patients. The incidence of microbleeds was significantly greater in the HD patients compared with the control patients. T 2 * -weighted gradient-echo imaging revealed a total of 44 microbleeds in 11 HD patients. T 2 -weighted imaging demonstrated 13 of 44 microbleeds as hyperintensity, whereas T 1 -weighted imaging demonstrated 12 lesions as hypointensity. T 2 -and T 1 -weighted imagings did not demonstrate any findings in 31 and 32 lesions, respectively. T 2 * -weighted gradientecho MR imaging is effective to detect microbleeds which may be a predictor of intracerebral hemorrhage in HD patients and should be included in the protocol for the study of cerebrovascular disease, because T 2 -and T 1 -weighted MR imaging recognizes microbleeds as lacunar infarction.

Keyhole surgery is partly replacing the standard pterional approach in patients undergoing surgery to treat aneurysms of the anterior circulation. We describe the pterional keyhole approach for the clipping of anterior circulation aneurysms and discuss the efficacy and safety of our keyhole craniotomy procedure. We treated 103 patients with 111 intracranial aneurysms by surgical clipping via the pterional keyhole approach and retrospectively compared the characteristics and clinical outcomes of the keyhole procedure and the standard pterional approach. We also compared the surgical results of the keyhole approach when the operator was an experienced neurosurgeon or a less experienced neurosurgeon guided by an experienced colleague. All keyhole operations were carried out successfully without enlargement of the craniotomy or a change to a different approach. The outcomes of the keyhole and the standard pterional approach in patients with subarachnoid hemorrhage were not significantly different. Favorable outcomes were obtained in patients with unruptured aneurysms treated by either experienced or less experienced surgeons. The pterional keyhole approach offers the same surgical possibilities as conventional pterional approaches for the treatment of anterior circulation aneurysms. It is safe and simple and yields favorable outcomes even if the operators are less experienced neurosurgeons. Careful patient selection and sufficient opening of the sylvian fissure are the key points for good outcomes and the prevention of intraoperative complications.

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A mother and daughter presented with a rare combination of moyamoya disease and Graves' disease. A 19-year-old woman experienced numbness in her right hand due to cerebral infarction during therapy for Graves' disease. Cerebral angiography demonstrated stenoses of the bilateral internal carotid arteries and net-like abnormal collateral vessels indicative of moyamoya disease. Her 52-year-old mother with a history of Graves' disease presented with left hemiparesis due to intracerebral hemorrhage; she recovered after hematoma evacuation. Postoperative angiography demonstrated stenoses of the bilateral internal carotid arteries and net-like abnormal collateral vessels indicative of moyamoya disease. Another otherwise healthy daughter manifested slight stenosis of the left internal carotid artery. After cerebral revascularization surgery the patients were able to return to their normal daily lives. These familial cases of moyamoya disease and Graves' disease indicate hereditary involvement in both diseases.