A case report of longitudinal extensive transverse myelitis: immunotherapy related adverse effect COVID-19 related immunization complications.

Transverse myelitis (TM) is a rare, acquired neuro-immunological spinal cord disorder that occurs with rapid onset of motor weakness, sensory deficits with bowel and bladder dysfunction. Patients being treated with immune checkpoint inhibitors (ICIs) for advanced malignancy have a known higher propensity of developing neuro immune complications. With the advent of COVID-19 pandemic there have been reported cases of TM with COVID-19 immunization. The reported infrequency of TM with both of the aforementioned causes makes delineation of the etiology challenging. We present a patient with metastatic small cell lung cancer (SCLC) on maintenance Atezolizumab immunotherapy who developed longitudinal extensive transverse myelitis (LETM) after administration of second dose of COVID-19 mRNA vaccine one day prior to presenting symptoms of acute paralysis of the lower extremity, sensory loss from chest down with overflow incontinence. A clinical diagnosis of myelopathy was supported by MRI of the spine illustrating enhancing lesions from C7-T7 concerning for LETM. A 5-day course of pulsed methylprednisolone followed by therapeutic plasma exchange for 3 days resulted in only minimal improvement in the neurologic exam with increased strength in his lower extremities while the sensory level remained unchanged. This case demonstrates the complication and symptomatology of TM in the setting of anti-PD-L1 monoclonal antibody with coincidental COVID-19 mRNA vaccine administration. The causal relationship between the vaccine and LETM is difficult to establish. However, the presence of a known inciting factor hints at a possible exaggeration of the existing neuro-inflammatory process.