Moyamoya disease associated with persistent primitive trigeminal artery. Report of two cases.

Two cases of moyamoya disease associated with persistent primitive trigeminal artery (PTA) are reported. The first patient was a 44-year-old man who experienced a sudden severe headache brought about by an intracerebral hematoma in the left temporoparietal lobe. Four-vessel study showed a right-sided PTA and moyamoya disease. The second patient was a 56-year-old woman with similar symptoms and a hematoma in the right temporoparietal lobe. Four-vessel study showed a left-sided PTA and moyamoya disease. Among the 212 PTA cases reported in the literature, none has been associated with moyamoya disease. Moreover, there are no cases of moyamoya disease among the 119 cases of persistent primitive hypoglossal artery (PHA), which is thought to be a vascular anomaly fundamentally similar to PTA. None of the 907 cases of moyamoya disease reported in Japan has been associated with either PTA or PHA. Nonetheless, the embryonic stage when PTA or PHA normally disappears partially overlaps that period when moyamoya-like vascular anomalies have been thought to arise. The possible developmental relationship between these two varieties of vascular abnormality is discussed.