Recurrent Bilateral Inflammatory Idiopathic Optic Neuropathy Treated with Mycophenolate Mofetil: Clinical and Radiological Course

Objective: To report the clinical characteristics and radiological findings of a patient suffering simultaneous bilateral recurrent inflammatory optic neuritis, who has been free of relapses following treatment with mycophenolate mofetil (MMF). Background: Inflammatory simultaneous visual loss is unusual. It is more frequently seen in acute disseminated encephalomyelitis (ADEM) or neuromyelitis optica (NMO). Evolution to multiple sclerosis (MS) after simultaneous bilateral optic neuritis is less frequent than after unilateral optic neuritis. Sequential optic neuritis has been described in Chronic Relapsing Inflammatory Optic Neuritis (CRION), which shows neither brain lesions nor oligoclonal bands in cerebrospinal fluid (CSF) and presents a relapsing course and a good response to immunosuppression. Case: A 41-year-old woman was evaluated for simultaneous bilateral visual loss. Magnetic resonance imaging showed enhancement of the chiasm and both optic nerves. No definite data of MS were found. We excluded infections, sarcoidosis, lupus, and other known causes of optic neuropathy. She was treated with intravenous methylprednisolone and tapering oral prednisone. After a partial recovery, she suffered two recurrences within three months. Following treatment with MMF, no further relapses have occurred during a 26 month follow-up. Discussion: Bilateral optic neuritis is part of two clinical syndromes: ADEM and NMO. Our patient differs from these entities on her clinical course and response to treatment. She is closer to the CRION cases (no oligoclonal bands, relapsing course, response to immunosuppression), except for her brain lesions and the bilateral involvement at onset. Conclusion: We suggest MMF as an effective treatment for idiopathic recurrent inflammatory optic neuritis not responsive to corticosteroids.