Guillain-Barre syndrome (GBS), an autoimmune polyneuropathy characterized by ascending weakness and characteristic cerebrospinal fluid (CSF) findings, has been identified in patients previously diagnosed with COVID-19, treated for COVID-19 infection, or vaccinated against the same. GBS is divided into axonal and demyelinating subtypes, and confirmatory testing such as electromyography and nerve conduction studies can help differentiate between subtypes. Here we present a case with recurrent COVID-19 infections, most recently treated with bebtelovimab, who developed acute motor sensory axonal neuropathy (AMSAN), a rare variant of axonal GBS.

A 33-year-old female presented with progressive ascending weakness and sensory loss that started two weeks after COVID-19 infection. She was fully vaccinated, however, had four episodes of COVID-19 infection within the past year and a half. Two weeks after the most recent infection, which was treated with bebtelovimab, she developed rapidly progressive weakness and sensory impairment in bilateral lower extremities quickly involving upper extremities. She received two rounds of intravenous immunoglobulin (IVIG) three and five weeks after symptoms onset. Her symptoms continued to progress requiring hospitalization. Exam showed severe weakness in all limbs with distal muscle atrophy in upper extremities. Imaging was negative. CSF demostrated albuminocytological dissociation. Nerve conduction studies concluded severe motor and sensory axonal neuropathy with active denervation which led to the suspicion of Acute Motor and Sensory Axonal Neuropathy (AMSAN), a rare variant of GBS. She underwent plasmapheresis with only minimal improvement.