Unique Magnetic Resonance Imaging Findings in Opsoclonus-Myoclonus Syndrome Secondary to the West Nile Virus.

Opsoclonus-Myoclonus syndrome is a rare neurological disorder that presents with oculomotor dysfunction and is associated with immunological triggers such as an infection. We present a patient with Opsoclonus-Myoclonus syndrome secondary to a West Nile virus (WNV) infection and focus on a unique series of magnetic resonance imaging findings. The following is a case report based on experience taking care of the patient as a member of the primary team in the hospital, chart review, and imaging findings obtained and reported through the department of radiology. A 61-year-old male presented with fatigue, ataxia, dysarthria, and fever after a recent cabin visit in the summer. The initial workup ruled out meningitis and stroke. The patient's condition deteriorated despite empiric treatment. Repeat magnetic resonance imaging (MRI) revealed patchy fluid-attenuated inversion recovery (FLAIR) hyperintensities in the cerebellar hemispheres. Further evaluation confirmed West Nile virus infection through positive immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies. This case underscores the importance of neuroimaging in evaluating encephalopathy, especially in the presence of multiple comorbidities. These findings contribute to the broader knowledge of West Nile virus encephalitis.