Myelopathy associated with mixed connective tissue disease: clinical manifestation, diagnosis, treatment, and prognosis.

Mixed connective tissue disease (MCTD) is a chronic autoimmune disease, which has a broad range of clinical manifestations shared by systemic lupus erythematosus, systemic sclerosis, polymyositis/dermatomyositis, and rheumatoid arthritis. MCTD is featured with high serum titers of anti-ribonucleoprotein antibodies and multiple system involvement. Its spinal cord involvement mainly manifests as transverse myelopathy (TM) and longitudinal extensive transverse myelopathy (LETM). Myelopathy in MCTD is extremely rare, and is usually characterized by serious neurological complications, such as paralysis or muscular paresis, sensory impairment, and smooth muscle dysfunction. Progressive clinical manifestations combined with laboratory examinations and magnetic resonance imaging examinations play important roles in the diagnosis of this disease. In order to prevent permanent neurological damage to the spinal cord, plasmapheresis and intravenous immunoglobulin can be performed in patients at the early disease stage. Early high-dose corticosteroids combined with cyclophosphamide, followed by low doses of immunosuppressors, can improve the long-term prognosis of patients. There are only nine global cases reported on MCTD associated with myelopathy at present. The death rate and disability rate of myelopathy in MCTD are extremely high. In this review, the pathomechanisms, clinical manifestations, auxiliary examination, diagnosis, differential diagnosis, treatment, and prognosis of myelopathy in MCTD were systematically elucidated.