Intracranial aneurysms and abducent nerve palsy.

BACKGROUND

Cranial nerve (CN) palsy may manifest as an initial presentation of intracranial aneurysms or due to the treatment. The literature reveals a paucity of studies addressing the involvement of the 6 CN in the presentation of cerebral aneurysms.

METHODS

Clinical patient data, aneurysmal characteristics, and CN 6 palsy outcome were retrospectively reviewed and analyzed.

RESULTS

Out of 1311 cases analyzed, a total of 12 cases were identified as having CN 6 palsy at the presentation. Eight out of the 12 were found in the unruptured aneurysm in the cavernous segment of the internal carotid artery (ICA). The other four cases of CN 6 palsy were found in association with ruptured aneurysms located exclusively at the posterior inferior cerebellar artery (PICA). For the full functional recovery of the CN 6 palsy, there was 50% documented full recovery in the eight cases of the unruptured cavernous ICA aneurysm. On the other hand, all four patients with ruptured PICA aneurysms have a full recovery of CN 6 palsy. The duration for recovery for CN palsy ranges from 1 to 5 months.

CONCLUSION

The association between intracranial aneurysms and CN 6 palsy at presentation may suggest distinct patterns related to aneurysmal location and size. The abducent nerve palsy can be linked to unruptured cavernous ICA and ruptured PICA aneurysms. The recovery of CN 6 palsy may be influenced by aneurysm size, rupture status, location, and treatment modality.