Abstract
Aneurysms of the distal anterior cerebral artery are relatively uncommon. In this paper a series of 26 patients with such aneurysms are reviewed.
Seventeen cases were men and 9 were women. All aneurysms were found to arise at the knee of the pericallosal artery (11: left; 14: right). In one case the aneurysm was found with azygos anterior cerebral artery. Twenty-two out of 26 cases were operated directly with the interhemispheric fissure approach in chronic phase more than 3 weeks from the last subarachnoid hemorrhage. The aneurysmal neck was clipped or ligated in 17 cases, coated with EDH-adhesive in 3 cases and pericallosal artery was trapped in 2 cases.
Clinical features were examined in 21 cases with ruptured aneurysm of the distal anterior cerebral artery before operation and in 22 operated cases after the surgery.
Of these cases, 11 cases showed prolonged impairment of consciousness of more than 7 days.
Various degrees of motor disturbances were found and motor disturbances were dominant on the lower limbs. After subarachnoid hemorrhage there were 3 cases with monoparesis of a leg, 4 with hemiparesis, 3 with hemiparesis and paresis of a contralateral leg, and 2 with tetraparesis. In 7 cases the paretic side was on the same side as the aneurysm and 5 out of these cases showed contralateral projection of the aneurysmal dome in carotid angiography and in operative findings. These findings suggested that the direction of the projection of the aneurysmal dome plays a significant role in the occurence of the paresis.
Psychic changes were recognized in 10 out of 19 cases prior to operation and 4 out of 20 cases after the operation except cases with disturbance of consciousness. Therefore, the over-all psychic morbidity rate was 63% which was almost the same as the rate of anterior communicating aneurysms. There were 12 cases with amnestic syndrome (2 with typical Korsakoff's syndrome), 5 with personality changes and 2 with akinetic mutism.
Urinary incontinence without impairment of consciousness was found in 3 cases.
Long-term follow-up results for more than 8 months after the operation revealed that 16 cases had no neurological deficits, 4 had minimal deficits and one was totally disabled.
From data obtained, it is concluded that the location of aneurysms was considered responsible in producing various neurological and psychiatric changes. The favorite location of this aneurysm was at the knee of the pericallosal artery where bilateral anterior cerebral arteries and cingulate gyri are not separated from each other. Therefore, the rupture of the aneurysm and surgical procedures easily give rise to the damage of bilateral cingulate gyri and corpus callosum and the vasospasm of bilateral anterior cerebral arteries. According to these conditions, various neurological and psychiatric changes appeared in cases with the aneurysm of the distal anterior cerebral artery.
