Chronic Oculomotor Nerve Palsy Presentation From Posterior Communicating Artery Aneurysm: A Case Series

Oculomotor nerve palsy (ONP) due to compression from posterior communicating artery (PCoA) aneurysms has been well described in the literature. Early treatment is advocated for reduction of rupture risk and improvement in ONP recovery. However, the actual natural history in patients with chronic symptoms is unclear. In this study, we present a case series of patients with greater than a week to several years of oculomotor palsy before definitive treatment.

This is a case series derived from a prospective-accrued database of patients treated at our institution between 1991 and 2024 who presented with subacute to chronic (≥1 week) ONP from PCoA aneurysm. Baseline characteristics, aneurysm size, and follow-up outcomes were evaluated.

A total of 17 patients were included in this series, of which 5 (29.4%) presented with aneurysm rupture. Most patients were female (94.1%) with a median age of 56 (IQR = 53-66) years. The duration of oculomotor palsy ranged from 1 week to 10 years. Eleven patients (64.7%) had microsurgical clipping, and 5 (29.4%) were treated endovascularly. Four patients (23.5%) had complete recovery of the ONP, all of whom with symptom duration of less than 5 weeks.

Chronic oculomotor palsy from untreated PCoA aneurysm is uncommon. Although ONP may not portend imminent aneurysm rupture, early definitive management is still recommended for better chance of ONP functional recovery.