Bilateral Internal Carotid Artery Aneurysms Presenting as Recurrent Al ternating Oculomotor Palsy: A Case Report with Therapeutic and Drug Considerations
Author(s): Sibi Joseph, Saumya Elzebeth Mathew, Lourdes de Fatima Ibanez Valde3, Humberto Foyaca Sibat*
Abstract
Alternating oculomotor (cranial nerve III) palsy is a rare symptom of bilateral intracranial aneurysms. Particularly in patients receiving or suspected of exposure to neuroactive or vasoactive drugs, these situations provide a considerable diagnostic difficulty since fluctuating symptoms may be mistaken as neuromuscular diseases.
We describe the case of a 39-year-old HIV-negative lady who had two separate episodes of ophthalmoplegia and unilateral ptosis when she arrived to Nelson Mandela Academic Hospital. The left eye was affected in the first episode in March 2025, and the right eye was affected in December of the same year. Drug-induced neuromuscular junction disorders and medication-related cranial neuropathies were taken into consideration in the differential diagnosis even though the patient had no history of alcohol abuse or recreational drug exposure.
CT angiography showed bilateral saccular aneurysms at the internal carotid artery bifurcations (right: 8 × 4 mm, lobulated; left: 4 × 3 mm), despite a thorough evaluation that produced negative results for autoimmune, infectious, and common neuromuscular etiologies, including the exclusion of drug or toxin-induced causes. Bilateral ophthalmoplegia was established by a thorough ophthalmological evaluation.
This case emphasizes the significance of meticulous medication and substance-use history in clinical diagnosis, as bilateral aneurysmal illness might mimic ocular myasthenia gravis and other drug-related neuromuscular disorders. Additionally, it highlights the diagnostic utility of CT angiography, especially in areas with limited resources where MRI may not be easily accessible. To the best of our knowledge, this is the first instance of recurring alternating ophthalmoplegia and the fourth documented case of bilateral carotid aneurysms at this anatomical position.