Background: Intracranial aneurysms may be a cause of ocular motor dysfunction, the third nerve being more often involved than the two other cranial ocular motor nerves.
Methods: We report the unusual occurrence of an isolated fourth nerve palsy related to a cavernous carotid aneurysm, angiographically confirmed. The patient already underwent clipping of a ruptured posterior communicating artery aneurysm 17 years earlier, revealed at that time by a third nerve palsy.
Results: Endovascular treatment of the cavernous carotid aneurysm was performed, resulting in complete recovery of the palsy.
Conclusion: Occurrence of an acquired fourth nerve palsy in a patient with a past history of aneurysm should prompt neurovascular imaging as multiple aneurysms may cause sequential ocular motor palsies.