421 - Adult Moyamoya Angiopathy

Abstract

The term moyamoya angiopathy is used to describe both moyamoya disease and moyamoya syndrome in children and adults. Moyamoya disease is idiopathic moyamoya angiopathy (i.e., without the presence of another disease), whereas moyamoya syndrome includes all cases of moyamoya angiopathy concomitant with other disease such as neurofibromatosis, Down syndrome, and sickle cell anemia. Moyamoya angiopathy is a cerebrovascular disease characterized by steno-occlusion of the internal carotid arteries intracranially at their terminal portion (i.e., anterior circulation of the circle of Willis) with resulting development of natural collateral vasculature termed moyamoya (Japanese for “puff of smoke”) at the base of the brain. The posterior circulation of the circle of Willis may also be involved. Clinical presentation mainly comprises cerebral ischemia in children and cerebral ischemia and/or hemorrhage in adults. The etiology is still unknown despite recent progressive accumulation of novel molecular biologic and genetic information. Although moyamoya has a higher incidence in Japan and Southeast Asia, diagnosis is on the rise in the Caucasian population owing to increasing awareness of its existence globally. Cerebral revascularization (direct or indirect) is the treatment of choice. This chapter presents up-to-date clinical and research information on moyamoya angiopathy as well as strategies of surgical revascularization with special focus on adult-onset moyamoya disease.