Oculomotor nerve palsy due to compression by posterior cerebral artery: case report

Isolated oculomotor palsy due to vascular compression at the root exit zone is an extremely rare entity. A 59-year-old male patient was presented with complaints of diplopia and mild ptosis. A thin-sliced MRI demonstrated that, the right posterior cerebral artery was impinging on the right oculomotor nerve at the root exit zone. Carbamazepine therapy was initiated, and after a month of medication, both diplopia and ptosis had completely resolved. Although it is extremely rare, vascular compression of the oculomotor nerve at the root exit zone should also be considered in the differential diagnosis of isolated oculomotor palsy.