Usefulness of somatosensory and motor evoked potentials for lesion localization

SEP can be used for monitoring transmissions in the contralateral side of the primary somatosensory cortex that pass through the thick myelinated fibers to the spinal cord and then travel along the posterior cord fibers and medial lemniscus pathway. In some cases, it would be useful to compare SEPs obtained after stimulation of the tibial nerve with those obtained after stimulation of the peroneal nerve, sural nerve, ulnar nerve, and median nerve because the volleys along the spinal cord run on different pathways [3].