Longitudinal Extensive Transverse Myelitis After Respiratory Syncytial Virus Vaccination With Positive Anti-Recoverin Antibodies.

Longitudinal extensive transverse myelitis (LETM) is a rare adverse event after vaccination. We present a case of severe myelitis in a 76-year-old man with positive anti-recoverin antibodies that occurred one week after RSVPreF3 vaccination against respiratory syncytial virus (RSV). The patient presented with severe spastic paraparesis, urinary retention, postural tremor of the upper extremities, hypesthesia, severely impaired proprioception and vibration sense in the lower extremities, and tonic spasms of the lower extremities. An MRI of the spine revealed a C3-T9 LETM, with inflammatory cerebrospinal fluid (CSF). The patient was found to have positive anti-recoverin antibodies in serum and CSF. While the patient had an initial improvement on high-dose intravenous steroids, he failed to respond to plasmapheresis. Subsequently, he received intravenous immunoglobulins with mild improvement of his symptoms. The patient's symptoms could be attributed to vaccine-induced inflammatory syndrome. The relationship between anti-recoverin antibodies and central nervous system involvement is likely due to the sharing of epitopes between recoverin and endogenous antigens of the central nervous system. The association between RSV vaccination and LETM has not been previously reported.