In fact there is no myelodysplasia; the correct term would be spinal cord cavernosis. People with spinal cord cavernous disease may have a 20-year shorter survival cycle than normal in more severe cases, and about 10 years in milder cases. Spinal Cord Cavitation is a chronic progressive degenerative disease of the spinal cord. The lesions, located primarily in the cervical and thoracic spinal cord, can occasionally occur in the brainstem and medulla oblongata. There are three main types of lesions: first, congenital developmental abnormalities. The second, acquired, is due to malformation of the base of the skull, in which cerebrospinal fluid enters the subarachnoid space from the fourth ventricle and continually impinges on the central canal of the spinal cord, causing it to enlarge and form spinal cavernous disease. The third type, ischemic necrosis of the spinal cord itself, forming a cavity. The symptoms of this disease are mainly segmental dissociative dysesthesia. In early patients, there is also spontaneous pain.