Primitive proatlantal intersegmental artery associated with moyamoya disease: A case report.

Primitive proatlantal intersegmental artery (PPIA) is rare and can be divided into types I and II. PPIAs can be associated with some anatomical variations and vascular diseases. However, no case of PPIA combined with moyamoya disease (MMD) has been reported. Here, we reported such a case. A 54-year-old man experienced headache for 1 month. The results of the neurological examinations were unremarkable. Magnetic resonance angiography and digital subtraction angiography revealed a right type I PPIA with MMD. The PPIA serves as an important collateral path for MMD patients. Because the patient only experienced headache, he was discharged and underwent follow-up observation. This case indicates that, rarely, PPIA can be associated with MMD and serve as a collateral vessel for MMD patients.