Cerebral Angiography in Moyamoya Syndrome Secondary to Vasculopathy in Down Syndrome

Abstract

Moyamoya disease (MMD) is an idiopathic intracranial
vasculopathy characterized by progressive bilateral
stenosis or occlusion of the terminal internal carotid
arteries (ICA) and their main branches with compensatory collateral angiogenesis. It is more prevalent among
Asian populations and has a typical angiographic
appearance. A similar angiographic pattern is associated
with vasculopathy due to several medical conditions
including Down syndrome and is termed Moyamoya
syndrome [1].
A 29-year-old non-Asian woman with Down syndrome
was presented with acute headache, transient visual loss,
and transient confusion for two days prior to admission.
MRI confirmed acute infarction in the left middle cerebral artery (MCA) territory, mainly in the left parietal
lobe. CT angiography suggested bilateral MCA stenosis
and near occlusion, and asymmetric vascular blush.
Diagnostic cerebral angiography confirmed MMS pattern with high grade focal stenosis of M1 segment of left
MCA (Figure 1), and near occlusion of proximal M1
segment of right MCA with reconstitution via collateral
arteries, and prominence of the lenticulostriate perforating vessels with significantly reduced capillary filling
distally (Figure 2). Collateral circulation was from leptomeningeal vessels from the posterior cerebral artery filling the temporal and parietal lobes. There was sparing of
the terminal ICAs, the external carotid artery branches,
and posterior circulation suggesting an early stage disease. At 4 months follow up, there was no recurrence of
symptoms after three months of dual antiplatelet therapy
(Aspirin 325 mg and Clopidogrel 75 mg daily) following by single antiplatelet. At nine months, a follow-up
MRI brain showed new lacunar infarct in the right
medial frontal lobe white matter. Patients did not
develop new neurological deficits.