Ionizing radiation causes dose-related damage to the spinal cord. This is particularly damaging when the irradiation is in the cervical area.
The benign form is associated with sensory impairment in the limbs, often with a positive Lhermitte's sign. These symptoms have a rapid onset and remit within a few weeks.
The more serious delayed myelopathy may appear between 6 months and 5 years after the radiation exposure. The initial sensory impairment is followed by progressive disruption of neuronal activity at the affected level. The spinal cord is swollen and infarcted. The patient is usually left paraplegic.
Last reviewed 01/2018