Abstract
We report identical twins presenting subarachnoid hemorrhage with intracranial aneurysms. These female twins were 52 and 64 years old, respectively at the onset of subarachnoid hemorrhage. The former, the younger sister, had 3 aneurysms in the right middle cerebral artery (MCA), the right internal carotid-posterior communicating artery (IC-PC) junction and the left C3 portion, and her sister, had 4 aneurysms in the IC-PC junction and the C3 portion of both sides.
The incidence of aneurysms in identical twins is very rare, and only 7 pairs have been previously reported. The features characteristic of twins' aneurysms can be summarized as follows. The age of the twins at onset is apt to approximate each other. The aneurysms of twins tend to be located in the same or mirror sites. And the incidence of multiple aneurysms is much higher (10/16, 62.5%) compared with those in sporadic cases. These features support previously reported data of the familial aneurysms and are very important as those of representative aneurysms cases on which the strongest genetic factors should be considered.
