Melkersson-Rosenthal syndrome: distal facial nerve branch palsies, masseter myopathy and corticosteroid treatment.

We described a case of Melkersson-Rosenthal syndrome in whom facial nerve branch palsies and an isolated masseter muscle atrophy were found in association with indolent multifocal facial soft tissue swellings. Non-caseating granuloma was found by the biopsy of swollen upper lip. Facial nerve conduction studies showed extremely low amplitude of compound muscle action potentials with slightly elevated distal latencies. Electromyogram of the atrophic masseter muscle indicated myogenic process. The persistent swellings responded dramatically to a 3 day-course of intravenous methylprednisolone (1,000 mg/day) followed by maintenance oral prednisolone but the facial nerve branch palsies responded rather slowly. Granulomatous involvements of the distal facial nerve branches and consequent wallerian degeneration appear responsible for this type of facial paralysis in Melkersson-Rosenthal syndrome and thus corticosteroid be used for a prolonged period in order to ensure the functional improvement.