Moyamoya disease associated with persistent primitive hypoglossal artery: report of a case.

An 8-year-old boy presenting with a transient weakness of the left extremities had a rare association of moyamoya disease and persistent primitive hypoglossal artery (PPHA). Digital subtraction angiography demonstrated intracranial moyamoya vessels and a PPHA on the right side. There was collateral blood flow from the posterior circulation to the anterior circulation, with the PPHA functioning as a blood supplier vessel. The patient underwent multiple burr hole formation, and neovascularization via the burr holes was observed on follow-up angiography. In this case, blood flow into the posterior circulation via the PPHA, which served as the collateral vessel to the moyamoya phenomenon, may have disturbed the spontaneous closure of the PPHA. Thus, this case serves as a basis for studying important pathogenic and embryological processes that contribute to the development of these vascular abnormalities. Copyright 2001 S. Karger AG, Basel