近年来研究证明,被动性脑血管扩张是本病发病的主要机理。当血压增高时,开始表现为脑小动脉收缩,以维持恒定的脑血流量,当血压水平超过脑自动调节上限时,脑小动脉就不再收缩,而出现被动性扩张。脑循环的自动调节失常也是本病发病的原因。正常情况下,脑动脉口径直接受动脉壁的 In recent years, studies have shown that passive cerebrovascular dilatation is the main mechanism of the disease. When the blood pressure increases, it starts to show contraction of the cerebral arterioles to maintain a constant cerebral blood flow. When the blood pressure level exceeds the upper limit of cerebral autoregulation, the cerebral arterioles no longer contract but passive expansion occurs. Autoimmune disorders of the brain is also the cause of the disease. Under normal circumstances, the diameter of the cerebral artery is directly affected by the arterial wall