Development of bilateral dural arteriovenous fistulae following pial synangiosis for moyamoya syndrome: case report.

Moyamoya syndrome predisposes patients to ischemic or hemorrhagic stroke due to progressive narrowing of intracranial vessels with subsequent small-vessel collateralization. Dural arteriovenous fistulae (DAVFs) are most commonly noted after venous sinus or cortical vein thrombosis and are believed to be primarily due to venous hypertension and elevated sinus pressures, although there is no known association with moyamoya syndrome, or with surgical treatment for moyamoya disease (MMD). The authors present the case of a 14-year-old girl with Down syndrome treated using pial synangiosis for MMD who subsequently was noted to have bilateral DAVFs. This case provides a new perspective on the origins and underlying pathophysiology of both moyamoya syndrome and DAVFs, and also serves to highlight the importance of monitoring the moyamoya population closely for de novo cerebrovascular changes after revascularization procedures.