The patient was a 30-year-old man who developed muscle weakness in both lower extremities, sensory deficits below the fourth thoracic spinal cord level, and bladder rectal dysfunction owing to cytomegalovirus (CMV) associated myelitis. His blood tests showed mononucleosis, hepatic dysfunction, and the presence of serum CMV-IgM antibodies, and T2-weighted imaging on MRI displayed a continuous high signal on the ventral side of the spinal cord. Although his medical history and laboratory tests did not indicate that he was immunocompromised, we speculated he had CMV-associated myelitis. As the first infection with CMV in a non-immunocompromised adult can result in mononucleosis, we considered that this patient developed myelitis after mononucleosis caused by CMV infection for the first time. CMV-associated myelitis in non-immunocompromised individuals is rare. In general, CMV infections are common in immunosuppressed individuals. However, in Japan, adults with CMV antibodies have recently been decreasing, and hence CMV infections in non-immunocompromised adults are expected to increase in the future.
Keywords: cytomegalovirus; cytomegalovirus mononucleosis; initial infection; myelitis; non-immunocompromised.