Isolated Hypertrophic Neuropathy of the Oculomotor Nerve

Background Hypertrophic neuropathy is a rare entity commonly associated with peripheral nerve, characterized by onion bulb formations. Its cranial nerve involvement is very rare; only 7 cases have been found in the literature. Case Description A 32-year-old white man with a 5-year history of intermittent right retro-orbital headache and mild right ptosis presented to the Neurosurgery Clinic. A magnetic resonance imaging of his brain demonstrated an enhancing lesion associated with the right third nerve. He underwent biopsy of the lesion, and its pathology report confirmed the diagnosis of hypertrophic neuropathy. Within 4 months, his third nerve palsy had completely resolved and was functioning fully. Conclusions Here, we report a first case of isolated hypertrophic neuropathy involving the oculomotor nerve.