Localized hypertrophic mononeuropathy involving the tibial nerve.

Localized hypertrophic neuropathy (LHN) is a disorder of unknown cause that presents with progressive, predominantly motor weakness in the distribution of a single nerve, with the histological appearance of the "onion bulb" formation. Because of its rarity, the condition is often ignored in the differential diagnosis of mononeuropathy. We report a case of LHN involving the posterior tibial nerve and review the literature.