Opsoclonus-Myoclonus-Ataxia Syndrome Following Dengue Infection: A Rare Post-Infectious Neuroimmunological Complication

Presenter: Sandeep Kumar Sivakumar

Authors:
Sandeep Kumar Sivakumar, Chozhan Mamallan, Gurunathan Srinivasan, Lakshmanan Sankaranarayanan, Praveen Nandha Kumar Pitchan Velammal, Harish Sidharth Veerachamy

Introduction

Opsoclonus-myoclonus-ataxia syndrome (OMAS) is a rare immune-mediated neurological disorder characterized by opsoclonus, multifocal myoclonus, and cerebellar ataxia. In adults, OMAS is most commonly associated with post-infectious or autoimmune mechanisms. Dengue-associated OMAS is exceedingly rare, with only a limited number of cases reported in the literature.

Methods

We present the case of a 31-year-old man who developed progressive gait instability, involuntary limb jerks, and abnormal eye movements approximately two weeks after laboratory-confirmed dengue infection (NS1 positive).

Results

Neurological examination demonstrated opsoclonus, stimulus-sensitive myoclonus, and broad-based ataxic gait. MRI of the brain was normal, and EEG showed no epileptiform activity. Cerebrospinal fluid analysis revealed mildly elevated protein without pleocytosis.

The patient was treated with high-dose intravenous methylprednisolone followed by an oral steroid taper and subsequent intravenous immunoglobulin (IVIG), resulting in marked neurological improvement.

Conclusions

Post-dengue OMAS is a rare but important immune-mediated neurological complication. Normal neuroimaging does not exclude the diagnosis. Early recognition and prompt immunomodulatory therapy can result in substantial neurological recovery and should be considered in patients presenting with characteristic neurological features following dengue infection.

Keywords

Opsoclonus-Myoclonus-Ataxia Syndrome (OMAS); Dengue; Post-infectious Neurological Syndrome; Neuroimmunology; Autoimmune Neurology; IVIG; Methylprednisolone; Case Report.