[Value of studying spinal evoked potentials in patients with thoracolumbar spinal cord lesions]

31 control subjects and 14 patients with dorso-lumbar spinal cord lesions were studied using the spEP (spinal evoked response). The presented responses were recorded by subcutaneous needle electrodes following stimulation of the peroneal nerve. Results from control subjects are presented first (triphasic negative potential, latency increasing with level of recording). The 14 patients were grouped according to their clinical symptoms. The prognostic value of the spEP response was considered. Results were as follow: flaccid paraplegia with no motor response to stimulation: no spEP was recorded; complete anatomoclinical paraplegia: the spEP was normal caudal to the lesion and negative rostral to the lesion; complete paraplegia with minor anatomical lesions: prognosis was good when spEP rostral to the lesion was recorded and poor when no response was detected; motor paraplegia: the spEPs rostral and caudal to the lesion were normal. In all cases, the levels of the lesions were in accordance with the upper level at which changes in spEPs were observed.