[Early somatosensory evoked potentials: a means of investigation of the lemniscal pathways (author's transl)].

The recording of the somatosensory evoked potentials (SEP's) elicited by stimulation of the median nerve is a non painful and non invasive mean to investigate the function of the different levels of the lemniscal pathways: peripheral nerves, dorsal root ganglia, dorsal funiculi, brainstem, thalamus, and somesthetic cortex. Recording technique, normative data in adults and abnormalities due to neurological diseases are reviewed. This investigation appears to be of peculiar interest in lesions of dorsal roots, cervical spinal cord and brainstem. SEP's recording may also be helpful for the functional testing of the somesthetic pathways in patients with disorders of consciousness.