PC2143: covid-19-associated Miller Fisher Syndrome with Long Latency Period: A Case Report

Introduction: COVID-19 has been known to affect multiple organ systems. Increasing reports of post-infection complications have been reported. Additionally, there are increasing reports of the impact of COVID-19 on pediatric health. Miller-Fisher Syndrome (MFS), a rare variant of Guillain-Barré Syndrome (GBS), has been reported after COVID-19 infection. We present the second youngest reported case, also the youngest known adult (26-year-old male) reported, to have had COVID-19-associated MFS. The case also describes the longest reported latency period (10 weeks) between infection and development of neurological symptoms for COVID-19-associated MFS.

Case Description: A 26-year-old male, with past medical history of COVID-19 infection approximately 10 weeks prior (infection in September 2020), presented to the emergency department with sudden onset right sided weakness for one day, preceded by ten days of worsening dysphagia and hoarseness, right facial droop, and numbness and tingling of the right face and tongue, all of which progressed bilaterally. Patient otherwise had no significant history. Patient was unvaccinated since the vaccine was not available to the public at the time. On admission, patient was tested negative for SARS-CoV-2. Based on the cerebrospinal fluid analysis, which revealed albuminocytologic dissociation, a diagnosis of MFS was made. The patient was immediately given intravenous immunoglobulin, and was ultimately transferred to a different facility for higher level of care. The paresthesia and weakness of the right face and bilateral upper and lower extremities resolved within 4 days of initiation of treatment. The patient reported resolution of neurologic symptoms with the exception of left sided facial weakness at the one year follow up.

Discussion: Miller Fisher Syndrome is a variant of Guillain Barré Syndrome. The average age of MFS is 44 years old. At 26 years old, this patient is currently the second youngest reported case of COVID-19-associated MFS, second after a case of a 7-year-old male. This case describes also the longest reported latency period (10 weeks) between onset of COVID-19 infection and the appearance of neurological symptoms. MFS typically has an average latency period of 10 days, but there is some evidence that one-third of patients who develop GBS report symptoms of an infection that occurred over 6 weeks preceding the onset of the condition. A possible limitation of this report is the lack of anti-ganglioside Q1b (anti-GQ1b) antibody testing, which is often used to help diagnose MFS, though the exact relationship between COVID-19-associated MFS and anti-GQ1b has not yet been explored.

Conclusion: As more reports of COVID-19-associated GBS and MFS appear in literature, we will likely see more pediatric cases. With COVID-19 affecting multiple systems, there could be increased variability to previously reported symptoms of MFS. Pediatricians and future studies should closely examine long-term follow-ups of patients previously diagnosed with COVID-19 as post-COVID complications become more prevalent.