False positive autoantibodies to glutamic acid decarboxylase in opsoclonus-myoclonus-ataxia syndrome after intravenous treatment with immunoglobulin.

摘要

Recently, a 33-year-old man was referred to our hospital because of rapidly progressive tremor and myoclonic jerks of the head, neck, trunk and all limbs in combination with ataxia. Intermittently spontaneous myoclonic eye movements were observed. The first complaint was trembling of the right hand 2 weeks earlier. His medical history was otherwise unremarkable. Family history was negative for neurological diseases. Neurological examination revealed multifocal myoclonus, most pronounced in axial muscles and increasing with action. Except for myoclonic jerks of the eyes, predominantly in the horizontal plane, there was no cranial nerve involvement. Furthermore, ataxia of four limbs and trunk was observed. There was an inability to walk, stand or sit without assistance. The clinical diagnosis of opsoclonus-myoclonus syndrome (OMS) was made. Additional investigations including extensive laboratory testing, CT-scan of the chest and abdomen, sonogra-phy of the testis, PET-scan of the body, dermatological evaluation and serological testing for anti-neuronal antibodies and infectious pathogens did not reveal a neoplastic, infectious, metabolic or toxic cause. Because of the rapid progression, intravenous immune globulin (IVIG) (0.4/(kg day)) was administered for 5 days, later followed by intravenous methylprednisolon (1000 mg/day for 3 days). There was a nearly complete remission after 20 weeks.