Opsoclonus-myoclonus-ataxia (OMA) is a neurologic condition consisting of spontaneous, multidirectional, arrhythmic eye movements and diffuse or focal myoclonus, with some patients experiencing ataxia and cerebellar signs.¹  In adults, OMA is often idiopathic or paraneoplastic in nature, though many cases have been shown to be post-infectious. Few cases of OMA related to West Nile Virus (WNV) have been described in the literature. These patients had varying clinical courses, with recovery in neurologic function either spontaneously, through treatment with steroids alone, with IVIG and steroids, and in at least one case, treatment with plasmapheresis. ²

We present the case of a 51 year old male with fevers, chills, myalgias, and diarrhea who subsequently developed involuntary movements of his upper extremities, head shaking, and involuntary extra-ocular movements in multiple directions.  He reported dizziness and imbalance. Exam was remarkable for constant involuntary ocular movements in all directions, mild weakness and hyporeflexia in lower extremities, and dysmetria. CT and MR head imaging were unremarkable. Based on examination, the patient was diagnosed with OMA. His clinical condition and mental status deteriorated, requiring intubation.  Ultimately, CSF analysis was positive for WNV IgM and IgG antibodies. IVIG and high dose steroids were administered with minimal improvement.  Plasmapheresis was performed, with complete resolution of myoclonus, and nearly complete resolution of opsoclonus.

WNV neuroinvasive disease typically results in an encephalitis and a flaccid paralysis, often in extremes of age. In this case, we demonstrate a unique presentation of OMA associated with WNV, emphasizing the spectrum of clinical manifestations related to the virus. We also present a proposed treatment course with steroids, IVIG, and PLEX, as management of this condition in patients with WNV, simultaneously highlighting the safety of these therapies in patients with this disease.