A case of sudden-onset transverse myelopathy suspected to be caused by fibrocartilaginous embolism

A 44-year-old male was admitted to our hospital because of sudden weakness and sensory loss in both legs following left scapular pain. He had a history of lower back pain but no vascular risk factors. Neurological examination on admission revealed flaccid paraplegia, a loss of both pinprick and vibratory sensations below the Th6 level, and bladder and rectal disturbances. Tendon reflexes were absent in both lower limbs. Diffusion-weighted imaging performed 5 hours after onset revealed an extensive high-intensity lesion at the Th2-6 spine levels, accompanied by a vague high intensity on T2-weighted images. CT angiography showed no abnormalities of the aorta or the artery of Adamkiewicz. Laboratory test results were normal and there was no evidence of coagulopathy. Autoantibodies, including anti-aquaporin-4 and antimyelin oligodendrocyte glycoprotein antibodies, were negative. The cerebrospinal fluid test was normal. The lesion had expanded to the whole thoracic cord and was markedly swollen on T2-weighted imaging at 5 days after onset. Immunotherapies, including intravenous methylprednisolone pulse therapy and plasma exchange, were ineffective. Although there was no evidence of any source of embolism, we found degenerative calcified changes in the fibrocartilage of the intervertebral discs, with Schmorl's nodes in the thoracic spines. We clinically diagnosed the patient with spinal cord infarction caused by fibrocartilaginous embolism. He developed deep vein thrombosis and was treated with edoxaban. His neurological symptoms did not improve during 55 days of hospitalization. In a case with sudden-onset myelopathy, fibrocartilaginous embolism should be considered.