A case of unilateral atypical moyamoya disease of adult onset with stenosis of the basilar artery

A 29-year-old, 39-week-pregnant female who had headache and nausea was admitted to our hospital. She bore a baby son by natural delivery after several hours. After labor, her headache was continuous. Brain CT scan demonstrated intracerebral and intraventricular hemorrhage. After conservative treatment for two weeks, her only neurological deficiency was visual field defect. Angiography demonstrated that her left internal carotid artery had partial stenosis at the C2 portion. Her right internal carotid artery had stenosis at the C2 portion. Her right middle cerebral artery was occluded at the M1 portion, and abnormal vascular networks had developed in the ganglionic region. Stenosis was also found in the basilar artery. We diagnosed her as being a case of adult-onset, unilateral, atypical Moyamoya disease with basilar artery stenosis. As our case was of adult-onset, and as she showed no ischemic signs, we did not think that reconstructive surgery was indicated. About the posterior circulation of Moyamoya or atypical Moyamoya disease, it was reported that in cases of juvenile onset the vertebral, basilar or posterior cerebral artery was sometimes stenosed or occluded, but, in adult-onset cases, stenosis or occlusion of the posterior cerebral artery would be an abnormality. Our case is a very rare example of unilateral atypical Moyamoya disease of adult onset with basilar artery stenosis.