Abnormal Cerebrovascular Network Related to the Internal Carotid Arteries

Abstract

APANESE neurosurgeons have recently observed in patients of their own race a variety of neurological disorders which are often transient and appear most frequently in young people. The typical angiographic appearance is that of narrowing or occlusion of both internal carotid arteries at the level of the siphon (C-1) together with a hemangiomatous network at the base of the brain (Fig. 1). These patients were initially reported as having a type of occlusive disease of the internal carotid artery. 1~ The entity has also been reported by other Japanese authors as occlusion of the circle of Willis, 3 telangiectasia, 1,11 or vascular malformation. ~,9 In 1964 we collected 21 case reports from the Japanese literature, added three of our own, r and concluded that the entity was unique to the Japanese. We reported the entity as "hemangiomatous malformation of bilateral internal carotid arteries at the base of the brain" and noted the similarity of the abnormal vasculature to the vascular network in the embryo. We noted, too, that the malformation was primarily limited to the distribution of the internal carotid arteries, s The term "cerebral rete mirabile" has some descriptive value although it is probably not entirely appropriate. The Western literature yielded only one similar case with bilateral involvement, and this patient was a Japanese woman. 1' Taveras and Wood ~ reported comparable cases in non-Japanese patients, but the occlusions were unilateral. Since our paper 6 in 1964, numerous other reports have appeared in the Japanese literature. Adding these to an additional number collected by writing all the neurosurgical clinics in Japan, we are now reporting a total of 96 cases.

Review of Past Research and Current Concepts on the Etiology of Moyamoya Disease

“…1) Inevitably, we must consider the possibility that multiple causes are involved to the etiology of moyamoya disease. 35,49,63) A``double hits hypothesis'' combining existing hypotheses is shown in Fig. 1.…”

“…None, for example, can answer the simple question of whether or not the primary lesions of moyamoya disease are localized to the terminal portion of the internal carotid artery. 1,35,49,62,63) Probably some studies, such as those of the abnormal value of cytokines, may reflect the secondary phenomena accompanying moyamoya disease rather than its essential cause. In addition, some phenomena, such as infection and HLA alleles abnormality, may be correlated to some trigger or enhancer of the disease.…”

“…63) The pathological entity of moyamoya disease was established in the 1960s. 35,49,63,67) Since then, particularly enthusiastic research has been conducted in Japan and progress has been remarkable in the past several decades. So far, many new aspects of the epidemiology have been uncovered and innovations in surgical treatment have been developed, including direct bypass surgery and other combined revascularization treatments.…”

“…35,49,62,63,67) The latter is thought to be a secondary phenomenon that compensates for the cerebral ischemia due to the primary internal carotid artery stenosis. The abnormally developed vascular network is defined as``moyamoya vessels.''…”

DNA typing of HLA in the patients with moyamoya disease

“…Moyamoya disease is a clinical entity with chronic occlusion of cerebrovascular system characterized by progressive steno-occlusive changes at the terminal portion of the bilateral internal carotid arteries (Kudo, 1968;Nishimoto and Takeuchi, 1968). An unusual vascular network at the base of the brain represents secondary collateral formation due to ischemic changes caused by a progressive occlusion of the circle of Willis (Suzuki and Takaku, 1969).…”