[A case of ruptured aneurysm associated with persistent primitive trigeminal artery and metopism].

The authors reported an extremely rare case of ruptured aneurysm associated with persistent primitive trigeminal artery (PTA) and persistent metopic suture (metopism). A 46-year-old female suffered sudden onset of a severe headache with nausea and vomiting on February 24, 1991. She was transferred to Kagoshima Prefectural Oshima hospital from the other clinic on the next day. She complained only of severe headache on admission, and neurological examination revealed no abnormal findings. Plain craniograms disclosed a persistent metopic suture extending from the bregma to the midportion of the frontal bone. Computed tomography demonstrated a mild subarachnoid hemorrhage. The right internal carotid angiograms showed a ruptured aneurysm in the middle cerebral artery. These angiograms also demonstrated PTA originating from the cavernous portion of the internal carotid artery and ending at the mid-portion of the basilar artery. The frequency of angiographic demonstration of persistent primitive trigeminal artery is 0.1 to 0.3%. It is well recognized that approximately 14% of patients with PTA also have intracranial aneurysm. The incidence of persistent metopic suture in adults is 1-10%. After an extensive review of the literature we have concluded that there has been no case report of a ruptured aneurysm associated with PTA and metopism. The authors think that, in this case, the coexistence may be only incidental.