Transient Radiation Myelopathy

Radiation myelopathy of the cervical cord may be revealed by Lhermitte's sign of electrical paraesthesia on neck flexion. A transient syndrome is described, occurring some three to four months after therapeutic irradiation, with electrical paraesthesia as the sole manifestation. This is contrasted with the features of progressive radiation myelopathy which usually appears after a longer latent period of one to two years. Transient radiation myelopathy does not (unless the evocative dose is above the accepted tolerance level) herald later and progressive cord degeneration. The pathogenesis of the condition is discussed in relation to the radiosensitivity of oligodendroglia, together with its significance in clinical neurology and radiotherapeutics.