Postpartum-Onset Moyamoya Disease: A Rare Cause of Stroke in Unexpected

Abstract

Moyamoya disease (MMD) is a chronic cerebrovascular occlusive disease that is characterized by progressive bilateral stenosis of the terminal portion of the internal carotid artery and its main branches. Cerebrovascular events are the primary presenting symptoms and are related both to stenosis and occlusion of the ICAs and their main branches. Detection of bilateral stenosis by cerebral angiography is considered the gold standard, but computed tomography angiography (CTA) is also an acceptable method of diagnosis. In the current literature, there are no precise data on the incidence of moyamoya disease in Europe and the United States. Also, the pathogenesis of MMD remains obscure, and genetic factors and inflammation are the two most representative mechanisms. Here, we report the case of MMD in a 29-year-old African American female who presented with an ischemic stroke for the second time that manifested after pregnancy. This case is important to increase awareness of the probability of this rare disease in Western countries as well as to call attention to pregnancy's accelerating effects of MMD. Careful, long-term neurologic and radiologic follow-up is essential in adult patients with MMD to prevent additional stroke events and improve outcomes.

Figure 1

Axial MRI brain imaging: (a)—(d) images from the first episode of stroke, with regions of restricted diffusion indicative of acute ischemia (arrows), primarily noted in the right cerebral hemisphere; (e)—(h) images from the second episode, with progressive bilateral ischemic changes (arrows).

Figure 2

Digital subtraction angiography images: (a) left internal cerebral artery (ICA) with focal distal ICA and proximal M1 arteriopathy (arrows) with prominent lateral lenticulostriate branches, indicating early collateralization of flow (arrowheads); (b) right internal cerebral artery (ICA) with focal distal ICA, proximal MCA (M1), and proximal ACA (A1) arteriopathy (arrows) with prominent lateral lenticulostriate branches, indicating early collateralization of flow (arrowheads).