Postinfectious SARS-CoV-2 Opsoclonus-Myoclonus-Ataxia Syndrome.

Background: The opsoclonus-myoclonus-ataxia syndrome (OMAS) represents a pathophysiology and diagnostic challenge. Although the diverse etiologies likely share a common mechanism to generate ocular, trunk, and limb movements, the underlying cause may be a paraneoplastic syndrome, as the first sign of cancer, or may be a postinfectious complication, and thus, the outcome depends on identifying the trigger mechanism. A recent hypothesis suggests increased GABAA receptor sensitivity in the olivary-oculomotor vermis-fastigial nucleus-premotor saccade burst neuron circuit in the brainstem. Therefore, OMAS management will focus on immunosuppression and modulation of GABAA hypersensitivity with benzodiazepines.

Methods: We serially video recorded the eye movements at the bedside of 1 patient with SARS-CoV-2-specific Immunoglobulin G (IgG) serum antibodies, but twice-negative nasopharyngeal reverse transcription polymerase chain reaction (RT-PCR). We tested cerebrospinal fluid (CSF), serum, and nasopharyngeal samples. After brain MRI and chest, abdomen, and pelvis CT scans, we treated our patient with clonazepam and high-dose Solu-MEDROL, followed by a rituximab infusion after her formal eye movement analysis 10 days later.

Results: The recordings throughout her acute illness demonstrated different eye movement abnormalities. While on high-dose steroids and clonazepam, she initially had macrosaccadic oscillations, followed by brief ocular flutter during convergence the next day; after 10 days, she had bursts of opsoclonus during scotopic conditions with fixation block but otherwise normal eye movements. Concern for a suboptimal response to high-dose Solu-MEDROL motivated an infusion of rituximab, which induced remission. An investigation for a paraneoplastic etiology was negative. CSF testing showed elevated neuron-specific enolase. Serum IgG to Serum SARS-CoV2 IgG was elevated with negative RT-PCR nasopharyngeal testing.

Conclusion: A recent simulation model of macrosaccadic oscillations and OMAS proposes a combined pathology of brainstem and cerebellar because of increased GABAA receptor sensitivity. In this case report, we report 1 patient with elevated CSF neuronal specific enolase, macrosaccadic oscillations, ocular flutter, and OMAS as a SARS-CoV-2 postinfectious complication. Opsoclonus emerged predominantly with fixation block and suppressed with fixation, providing support to modern theories on the mechanism responsible for these ocular oscillations involving cerebellar-brainstem pathogenesis.