脳の動脈硬化性疾患に関する総合的研究

Abstract

The aim of the present project was to contribute to the eradication of cerebrovascular diseases (CVD) by means of a multi-facted approach. The studies have been conducted on each sub-project described below : 1) definition and diagnostic criteria, 2) cerebral blood flow (CBF) and metabolism, 3) neurochemical and neuropathologic approaches to vascular dementia, 4) effects of aging on arterio-/atherosclerosis of the brain, and 5) treatment and secondary prevention.Studies performed during the study period are summarized as follows. 1) The definition and diagnostic criteria for CVD was revised referring to findings of modern diagnostic devices such as CT, MRI, PET, etc. 2) CBF and cerebral metabolism in the acute stage of cerebral ischemia were evaluated in relation to the timing of appearance of hypodense area on CT and availability of collateral blood flow on angiograms. Vascular reactivity in acute ischemia and effect of anti-hypertensive therapy on autoregulation were studied in both humans and animals. 3) White matter pathology in demented patients was investigated with neuroimaging, electron microscopy and tissue culture. Neurochemical approaches were focused on intracellular metabolism of protein, neurotransmitters and enzymes in the ischemic brain. 4) Effects of aging on cerebrovascular system were represented by initimal thickning with medial thinning and a decrease in elasticity. Known risk factors were less important in development of stroke in aged population. 5) Progression and regression of arterial lesions were demonstrated by B-mode ultrasound technique and cerebral angiography. Long-term follow-up studies in stroke patients were carried out in relation to recurrence, changes in CT findings and CBF.Collaborative study (retrospective) on efficacy of anti-platelet therapy was completed, and revealed that this agent was effective in secondary prevention of stroke without increasing risks of brain hemorrhage. On-going prospective study will be continued in the next project.