Moyamoya vasculopathy is characterized by progressive stenosis of the distal intracranial internal carotid artery resulting in formation of a network of collateral vessels due to poor perfusion with heterogeneous presentations and etiologies. Hemorrhage in Moyamoya most commonly presents as intraventricular hemorrhage (IVH) with or without intracerebral hemorrhage, due to lenticulostriate formation in close proximity to the ventricles. Moyamoya disease and syndrome are respectively defined by absence or presence of comorbidities predisposing to development of the underlying vasculopathy. Moyamoya syndrome has been associated with comorbidities including infections, autoimmune diseases, malignancies, genetic disorders, or radiation exposure.

A 61 year old female with seropositive rheumatoid arthritis (RA), presented with severe headache and encephalopathy. CTA Head/Neck showed bilateral primary IVH, requiring temporary EVD placement. DSA revealed chronic R MCA occlusion with hypertrophied lenticulostriate and anterior choroidal artery collaterals, consistent with a pattern of Moyamoya vasculopathy, and identified as the source of hemorrhage. Rheumatology consulted for optimization of RA management given concern for acquired Moyamoya syndrome. Patient improved clinically and will undergo a right STA to MCA bypass to reduce risk of recurrent hemorrhage along with escalation of her immunosuppressive regimen.

Here, we present a case of Moyamoya vasculopathy resulting in primary IVH, with no identified risk factors other than poorly controlled RA. Compared to other autoimmune conditions such as SLE and Sj?gren Syndrome, the association between Moyamoya and RA is less well described. Only one prior case reported Moyamoya vasculature in a patient with RA, who presented with multiple ischemic strokes.  Given the significant morbidity risk, this case demonstrates the importance of management of comorbid autoimmune conditions that can predispose patients to developing Moyamoya syndrome; the pathophysiology of which remains poorly understood, but is thought to be related to secondary immune-related injury and is a topic of future investigation.