Abstract
Background. Spontaneous activity originating from the spinal cord has been sporadically reported in humans. Objectives. Investigation of such rhythmic activity of the trunk and legs in a 49-year-old male patient who had a complete severance of the spinal cord at the fifth thoracic vertebra. Methods. A multichannel electromyography (EMG) study was performed together with kinematics measurements obtained from an Optotrak system.Results. Episodes of rhythmic trunk and lower limb movements started 6 to 7 years after the spinal lesion, recurred at 2 to 3 month intervals, and continued uninterrupted for 2 to 3 days despite continuous delivery of intrathecal baclofen. Several muscles discharged more or less synchronously on both sides but others clearly alternated, for instance, between hip flexors and knee or ankle extensors. Sensory stimuli (hip repositioning or skin pinch) altered significantly the baseline rhythm of about 1 Hz. The patient had both hips injected with corticosteroids and was free of these episodic rhythmic crises for more than 6 months. Conclusion. The rhythmic activity observed in the patient appeared related to the activation of a spinal pattern generator akin to what has been described in most animal species after complete spinal lesions.