A source of haemorrhage in adult patients with moyamoya disease: the significance of tributaries from the choroidal artery.

This study concerns 19 patients over 16 years of age with Moyamoya disease. Ten cases of intracranial haemorrhage, as the initial haemorrhagic event in patients aged from 21 to 55 (haemorrhagic group) and 9 cases of ischaemic events in 18- to 53-year-old patients (ischaemic group) were included. All haemorrhages were associated with intraventricular haemorrhages (IVH); and all but one case of thalamic haemorrhage were thought to be primary IVH (2 cases of small paraventricular haemorrhage; 2 of small haemorrhages in the splenium; 5 with no intracerebral haematoma). In the 9 patients of the ischaemic group, there were 2 cases of transient ischaemic attacks and 7 of cerebral infarction. Angiographic evaluations demonstrated that the abnormal basal vessel formation and the collateral supplies from the external carotid arteries were poorly developed in both groups. In contrast, the collateral circulation via the choroidal and posterior pericallosal arteries was well demonstrated. Furthermore, marked enlargement of the choroidal arteries and the medullary arteries derived from them was seen more frequently in the haemorrhagic group. These findings suggested that the haemodynamic load in the vessels supplying the walls of the posterior parts of the ventricles and the periventricular region was increased, especially in the haemorrhagic group. Those vessels were considered to be important sites of IVH in adult patients with Moyamoya disease.