Opsoclonus-Myoclonus Syndrome Associated with Mumps Virus Infection

BACKGROUND: Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disorder that is characterized by involuntary eye movements and myoclonus. OMS exhibits various etiologies, including paraneoplastic, parainfectious, toxic-metabolic, and idiopathic causes. The exact immunopathogenesis and pathophysiology of OMS are uncertain. CASE REPORT: We report the case of a 19-year-old male who developed opsoclonus and myoclonus several days after a flu-like illness. Serological tests revealed acute mumps infection. The findings of cerebrospinal fluid examinations and brain magnetic resonance imaging were normal. During the early phase of the illness, he suffered from opsoclonus and myoclonus that was so severe as to cause acute renal failure due to rhabdomyolysis. After therapies including intravenous immunoglobulin, the patient gradually improved and had fully recovered 2 months later. CONCLUSIONS: This is the first report of OMS associated with mumps infection in Korea. Mumps infection should be considered in patients with OMS.