Miller-Fisher syndrome associated with SARS-CoV-2: a case report

SARS-CoV-2 infections are increasingly associated with neurological complications, including immune-mediated neuropathies. Miller-Fisher syndrome is a rare variant of Guillain-Barré syndrome characterised by the triad of ataxia, ophthalmoplegia and areflexia. Here we present a case of Miller-Fisher syndrome following COVID-19 infection. The clinical presentation was a short history of a rapidly-progressive peripheral sensorimotor neuropathy with bulbar dysfunction and facial weakness following mild COVID infection. Examination revealed global areflexia and a broad-based ataxic gait. CSF analysis revealed albuminocytological dissociation and neurophysiological testing later supported the diagnosis. The patient required high flow nasal oxygen therapy for respiratory dysfunction in a level 2 care setting and received immunological treatment with intravenous immunoglobulins. We conclude that Miller-Fisher syndrome needs to be considered in patients presenting with new sensorimotor dysfunction following SARS-COV-2 infection. Early recognition is key given the propensity to cause life-threatening respiratory failure, and early administration of immunological treatment is associated with improved prognosis.