A retrospective analysis of 111 patients with aneurysms associated with Moyamoya disease is presented. The subjects comprised of our 12 cases and 99 other well-documented cases. These 111 cases had 131 aneurysms. There were 48 males and 63 females. The average age was 40.3 years. The clinical manifestations were intracranial haemorrhage in 99 cases (89%), and ischaemic events in 9 cases (8%), but no mention was made of these in the last three cases (2%). The Hunt and Kosnik grades were grade 1 in 8%, grade 2 in 23%, grade 3 in 31%, grade 4 in 35%, and grade 5 in 3%. Of the 131 aneurysms, 73 (56%) were found distributed around the circle of Willis, 24 (18%) in the basal ganglia, 29 (22%) on collateral vessels, and 5 (4%) on other vessels. Forty-six percent of the cases were treated surgically, 51% conservatively, and 3% by endovascular procedures. The surgical procedures for the aneurysms were; neck clipping in 49%, aneurysmectomy in 18%, wrapping of the aneurysm in 11%, coating or cautery of the aneurysm in 7%, and revascularization only in 11%. The outcomes were Glasgow Outcome Scale 1 in 30%, 2 in 22%, 3 in 11%, 4 in 1%, and 5 in 25%. The main reasons for the unfavourable outcome were initial poor clinical grade and rebleeding. Follow-up angiography of 25 aneurysms demonstrated that all aneurysms in the basal ganglia or on the collateral vessels disappeared. We recommend surgical intervention for aneurysms associated with Moyamoya disease to prevent rupture or rebleeding, especially for aneurysms around the circle of Willis. However, direct surgery is not recommended for aneurysms found in the basal ganglia or on the collateral vessels.

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In this article, the authors present five cases of dural arteriovenous fistula (AVF) that developed in the transverse-sigmoid sinus 2 to 6 years after sacrifice of the sigmoid sinus because of tumor involvement. The original tumor was meningioma in two patients and neurinoma, glomus jugulare tumor, and ameloblastoma in one patient each. The involved sigmoid sinus was resected along with the tumor and ligated at the normal edge; all that remained of the sigmoid sinus was a small stump on the retrosigmoid portion. Serial angiography performed before and after tumor surgery revealed no abnormal arteriovenous communications or dural AVF in any of the cases. Although many reports have suggested that sinus thrombosis is a precipitating factor in the pathogenesis of dural AVFs, this has been difficult to verify because of the small number of cases in which serial angiography was performed before the development of a dural AVF. In all of the cases presented in this article, surgical resection of a dural AVF and histological examination were performed. Subintimal fibrous thickening was marked, and the sinus wall was found to contain many dural vessels. Organized thrombosis with neovascularization was seen in only two patients. These cases demonstrate that subintimal fibrous thickening a hypertrophied sinus wall secondary to increased intrasinus pressure or sinus thrombosis occurring after sinus occlusion can provoke the development of a dural AVF within the course of a lifetime. Maintenance of intrasinus blood flow may be very important to prevent this late postoperative complication.

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Previous studies') conducted to develop an objective measure of human mental workload confirmed the utility of occipital midline beta-2 (OzƒÀ2) amplitude. These studies further showed that the OzƒÀ2 amplitude was correlated with a subject's mental activity. In applying this to measure the mental workload of workers engaged in mental work, it is first necessary to ascertain whether the Oz/32 amplitude is influenced by physical activity, since ordinary mental work must be accompanied more or less by physical activity. The present paper refers to an experiment to determine the effects of bicycle exercise on OzEEG amplitude and heart rate.