Opsoclonus-myoclonus syndrome associated with multiple system atrophy

Opsoclonus-myoclonus syndrome (OMS) is well known as a paraneoplastic syndrome or as a parainfectious neurologic complication. However, OMS associated with a neurodegenerative disorder has not been described previously. A 48-year-old woman had been diagnosed as multiple system atrophy-parkinsonian type (MSA-P) based on the findings of dopamine non-responsive parkinsonism with autonomic failure and typical findings on magnetic resonance imaging 5 years ago. She exhibited recurrent asynchronous and arrhythmic myoclonic movements of the upper limbs and abdomen with a very short duration, and involuntary eye movements, which were repetitive, rapid, random, multidirectional, conjugate saccades of irregular amplitude and frequency at rest. Based on hematological and radiological findings, the diagnosis was advanced MSA-P associated with OMS. As far as we are aware, there have not been any previous reports of such a case.