Isolated third nerve palsy associated with a ruptured anterior communicating artery aneurysm

Abstract

In very rare circumstances, an ACOM aneurysm may produce an isolated third nerve palsy. The etiology of the palsy is likely related to clot formation and/or irritating blood products.

3rd Nerve Palsy After Microsurgical Clipping of Basilar Top Aneurysm

“…Direct com¬pression by the aneurysm is the most classic and common cause. Other causes include direct injury to the third nerve intraoperatively [1][2][3][4][5][6], microvascular ischemia [7][8][9], focal hemato¬ma formation [3], vasospasm [8][9][10][11][12], anomaly of the vessels along the oculomotor nerve [10], elevated intracranial pressure and herniation, compression by intracranial structures other than aneurysms [7], and undetermined ori-gins [11]. In the present case, compression by aneurysm may not be possible because of the anatomi¬cal distance between the two entities.…”

An Unusual Complication of Hypertensive Hemorrhage – Delayed Oculomotor Palsy: Case Report and Literature Review

“…Recurrent episodes following pituitary hemorrhage, presumably with subarachnoid extension have been noted [4]. Both oculomotor and trochlear palsies have been reported following rupture of ACA and MCA aneurisms [5, 6]. Abducens palsy following aneurismal SAH has also been documented [7].…”

Oculomotor nerve palsy in the setting of an anterior cerebral A2 segment aneurysm

“…However, the mechanism of action for injury to the nerve by an A2 segment aneurysm remains less obvious 7. Nerve damage in the setting of an aneurysm can come from many sources, including herniation, mass effect caused by hematoma or the aneurysmal sac itself, irritation by blood products and ischemia 5. Given the anatomic positions of the oculomotor nerve and the ACA, one would hypothesize that direct physical irritation of the nerve by the aneurysmal sac would be less of a factor and that hemotoxicity and ischemia would play more of a role in such rare cases.…”

“…The oculomotor deficits caused by these aneurysms can also be explained by their anatomic proximity to the third cranial nerve. Very rare cases of oculomotor nerve dysfunction resulting from anterior communicating artery aneurysms have been described by White and colleagues 5. Nonetheless, the third nerve paresis caused by anterior cerebral artery A2 segment (ACA-A2) aneurysms has not been reported and cannot be explained by the anatomic relationship between these nerves and vessels 6.…”