Overlapping syndrome of anti-MOG antibody-associated disease and anti-mGluR5 encephalitis manifested as optic neuritis: A case report

Abstract

Rationale: Anti-Myelin oligodendrocyte glycoprotein (MOG) and anti-metabotropic glutamate receptor 5 (mGluR5) double antibody positive encephalitis characterized by optic neuritis is extremely rare. We present a case of overlapping syndrome of MOG-IgG-associated disease and anti-mGluR5 encephalitis manifested as optic neuritis. Patient concerns: A 60-year-old Chinses woman presented to the hospital with progressive vision loss and headache for 1 week. The cerebrospinal fluid examination was within the normal range. Visual evoked potentials study disclosed prolonged latency of P100 bilaterally. Fundus examination revealed indistinct boundaries of both optic discs. Her brain magnetic resonance imaging showed patchy hyperintensity in the posterior horn of the left ventricle and the left optic nerve. Her serum was positive for anti-MOG and anti-mGluR5 antibodies. Diagnosis: The patient was diagnosed with overlapping syndrome of anti-MOG antibody-associated disease and anti-mGluR5 encephalitis mainly based on the clinical symptoms and further test of the antibody in serum. Interventions and outcomes: She was subsequently subjected to empirical treatment with intravenous methylprednisolone. After discharge, she was given a tapering dose of oral prednisone, alongside mycophenolate mofetil. On outpatient follow-up, her symptoms showed no relapse after 1 month, and her condition remained stable. Lessons: Early recognition of autoimmune encephalitis is crucial. The detection of cerebrospinal fluid and serum of autoimmune encephalitis and demyelinating diseases of the CNS, including MOG-IgG and mGluR5-IgG, should be strengthened in order to make a precise diagnosis and develop a comprehensive treatment plan in a timely manner.