Alagille syndrome associated with angiographic moyamoya.

We describe the case of a 13-year-old boy with Alagille syndrome in whom intracranial imaging was performed following a seizure. The MRI and MRA revealed changes of angiographic moyamoya within both the anterior and posterior circulation. This very rare manifestation of the systemic vasculopathy in Alagille syndrome has not been previously documented in a patient without a focal neurological deficit. We discuss the potential role of routine intracranial imaging in patients with Alagille syndrome.