Myelopathy and peripheral neuropathy after X-ray therapy

Three patients with injury to the spinal cord after X-ray therapy are reported. One patient suffered from a chronic progressive myelopathy, whereas two others were considered to have a peripheral motor neuropathy due to selective damage to the motoneurons. The prognosis of patients with peripheral motor neuropathy is good, in contrast to chronic progressive myelopathy which most often leads to severe disability and death. Characteristically there is a latent interval from months to years between completed radiation therapy and the appearance of neurological symptoms. The mechanism for delayed radiation injury to the cord is at present unknown, but the possibilities of fibrosis, injury to the microcirculation, or direct injury to the nervous tissue are discussed. The importance of a correct diagnosis before further treatment is decided upon is stressed. The most difficult differential diagnosis is intraspinal metastases