A 39-year-old woman, who had suffered from severe headache followed by disturbance of consciousness which was caused by the ictus of ventricular hemorrhage, was angiographically shown to have an aneurysm arising from the posterior choroidal artery associated with Moyamoya disease.
Within several days her symptoms due to ventricular hemorrhage have gradually subsided and she was discharged 3 months later without any neurological deficit.
During and after hospitalization the posterior choroidal artery aneurysm was treated conservatively under careful observation by means of follow-up CT scanning with the aid of contrast infusion.
On CT scanning, having been detected as a tiny enhanced spot adjacent to the lateral wall of the trigone of the right lateral ventricle, the aneurysm finally disappeared on the 111th day after the attack.
Corresponding to disappearance of an enhanced spot on CT scanning, the posterior choroidal artery aneurysm couldn't be angiographically demonstrated any more. This presented case and some previously reported cases show that an aneurysm arising at the Moyamoya vessel itself or its collaterals is thought to be not true one but a pseudo-aneurysm and should be treated conservatively.
Nowadays, CT scanning with contrast infusion has enabled us to complete follow-up studies as an alternative procedure of such an aneurysm safely and repeatedly, not requiring frequent hazardous angiography.
