We report the case of a 9-year-old girl admitted with fever, headache, and a cerebrospinal fluid lymphocytic pleocytosis. Polymerase chain reaction was positive for human herpes virus 6. She subsequently developed ataxia and bilateral loss of vision. Magnetic resonance imaging (MRI) showed bilateral optic nerve lesions with extension to optic chiasm and a short-segment myelitis. Serologic studies were positive for Borrelia burgdorferi IgM. Anti-aquaporin 4 antibody was negative and anti-myelin oligodendrocyte glycoprotein antibody (MOG) positive. After intravenous methylprednisolone, ceftriaxone, and intravenous immunoglobulin, her vision slowly recovered. The patient was discharged with only mild visual acuity loss, 1 month after admission. Brain MRI was repeated later and was normal and MOG assay became negative. In our view, this patient suffered from a postinfectious, anti-MOG-mediated, spinal cord and optic nerve demyelination.
Keywords: Lyme borreliosis; bilateral optic neuritis; myelin-oligodendrocyte glycoprotein antibodies; neuromyelitis optica spectrum disorders.