Three adolescent cases of opsoclonus-myoclonus (OMS) that followed infection with mycoplasma pneumoniae are reported from University Hospital, Bern, Switzerland. Case 1. A 10-year-old girl presented with a 3-day history of uncontrolled eye movements and whole body tremor, followed by cerebellar ataxia. Two weeks previously she had pneumonia due to M pneumoniae (nasopharyngeal PCR positive, and IgM antibodies elevated). MRI brain showed no signs of inflammation, and tests for a paraneoplastic etiology were negative. Following methylprednisolone, symptoms slowly improved. Steroids were weaned over 10 months, and at 30-month follow-up, no relapse had occurred. Two further cases, both aged 14 years, developed OMS 2 to 4 weeks following M pneumoniae respiratory infection. Neuroblastoma was ruled out. Recovery from OMS occurred after 2 to 4 weeks of methylprednisolone therapy. [1]

COMMENT. One previous case of OMS following M pneumoniae infection is cited in a 4-year-old girl [2]. Among pediatric cases, OMS generally presents between 6 months and 3 years of age, and neuroblastoma is present in 50% cases. In the above parainfectious childhood cases of OMS, response to steroid therapy was rapid and generally complete, and the long-term outcome was favorable. Neurological complications of M pneumoniae include meningoencephalitis, acute disseminated encephalomyelitis, acute transverse myelitis, cerebellitis, abducens nerve and Bell’s palsies, and Guillain Barre syndrome. [3]