Ophthalmoplegia Caused by Non-Aneurysm Neurovascular Conflict: Clinical Cases of Eight Patients

Background: Neurovascular conflict (NVC) is a rare but often overlooked cause of oculomotor cranial nerve (OCN) palsy. In this study, we aimed to enhance understanding of NVC as a potential cause of cranial nerve palsies by summarizing the characteristics of eight OCN palsy cases associated with NVC and reviewing previously reported cases. Methods: A retrospective case series of eight patients with OCN palsy due to NVC was analyzed. Diagnosis was made using 3.0 Tesla magnetic resonance imaging (MRI) with 3D-fast imaging with steady-state acquisition (3D-FIESTA) sequences. Differential diagnoses like myasthenia gravis, inflammatory diseases, and aneurysms were excluded. Results: The study involved eight patients (six males, two females), aged 34–78 years (average 58.4 years). Six had abducens nerve palsy, and two had partial oculomotor nerve palsy, all exhibiting painless partial ophthalmoplegia. Imaging revealed OCN compression by various arteries: abducens nerve palsy was due to the basilar artery (three patients), vertebral artery (one patient), and anterior inferior cerebellar artery (two patients); two cases of partial oculomotor nerve palsy were caused by compression of the superior cerebellar artery and the posterior cerebral artery, respectively. Conclusion: NVC should be considered in patients with abducens nerve palsy, particularly those with intermittent symptoms and painless ophthalmoplegia, especially if they have atherosclerotic risk factors; in this descriptive single-center cohort, diagnosis was supported by high-resolution MRI, including 3D-FIESTA and magnetic resonance angiography.