Late delayed postradiation spinal myoclonus or psychogenic movement disorder?

We describe a patient with intermittent, at times rhythmic trunk flexion movements. Neurophysiological assessment excluded a psychogenic movement disorder. The segmental spinal myoclonus occurred 6 years after radiation therapy of the brain and entire spinal cord, and we suggest this patient to be the first case of a late-delayed sequela of spinal cord irradiation presenting as segmental spinal myoclonus.