A case report of thrombocytopenic COVID-19 and Miller–Fisher syndrome on a concurrent chronic immune neuropathy

Abstract

Rationale: Miller–Fisher syndrome (MFS) is a rare subtype of Guillain–Barre syndrome with classic features of ataxia, areflexia, and ophthalmoplegia that can be caused by a preceding infection including COVID-19. We present a current, asymptomatic thrombocytopenic COVID-19 infection as a cause of MFS in a 60-year-old male with a concurrent chronic immune neuropathy. Patient concerns: A 60-year-old male presenting with acute symptoms of MFS including ataxia, areflexia, and ophthalmoplegia on a chronic immune neuropathy for at least 1 year and concurrent asymptomatic COVID-19 positive infection. Diagnosis: MFS suspected secondary to a current thrombocytopenic COVID-19 infection. Interventions: Five days of intravenous immune globulin with continued monthly intravenous immune globulin as an outpatient, follow-up long-term in a neuromuscular clinic, electromyography as an outpatient, and continued physical therapy. Outcomes: The patient significantly improved after initial treatment. Lessons: The full effect of COVID-19 on the various Guillain–Barre syndrome subtypes is unknown, although it clearly can be a cause of the various variants including being caused by a current, asymptomatic infection.