An autopsy case of a giant aneurysm of the anterior communicating artery

A 64-year-old female was admitted to our hospital on 8, July, 1980 with a history of three previous subarachnoid hemorrhages. Neurological examinations revealed incontinentia urinae, gait disturbance, recent memory disturbance and motor weakness on the left side. The results of the neuroradiological examinations were as follows. Plain X-ray films showed a ring-like calcification in the right frontal region. A plain CT scan showed a ring-shaped iso- and high-density area in the intra hemispheric region, the intra bilateral anterior horn of the lateral ventricle, the intra septum pellucidum, and the intra anterior part of the third ventricle. A small high-density region was enhanced as an island within it by means of a Conray infusion. Left carotid angiography showed a large aneurysmal shadow arising from the anterior communicating artery and another from the left middle cerebral artery. In the venous phase the venous angle was supero-posteriorly shifted, and the septal vein was elevated. She died unexpectedly with a status epilepticus of unknown origin. Clinically, rerupture was not verified. An autopsy specimen revealed that a giant aneurysm (6 x 5 x 4 cm in size) arising from the anterior communicating artery occupied the intra ventricular space, the anterior horn of the lateral ventricle, and the right thalamic region. Also, there was a large berry aneurysm (2 x 1.7 x 1.5 cm in size) arising from the middle cerebral artery. A coronary section through the giant aneurysm showed a markedly compressed left lateral ventricle, right thalamus, and hypothalamus, while the third ventricle had shifted toward the left side. (J.P.N.)