L'apport diagnostique et pronostique des potentiels évoqués somesthésiques par stimulation tronculaire et dermatomale dans les conflits disco-radiculaires lombaires : A propos de 120 cas opérés

Lower-limb somatosensory evoked potentials (SEPs) of nerve-trunk (peroneal nerve, posterior tibial nerve) and dermatomal (L5 and S1) stimulation were recorded in 120 patients suffering from lumbosacral disk disease. Recordings were performed before surgery and on Days 4 and 50 after surgery. Electromyography was also performed before surgery. Dermatomal SEPs were shown to be sensitive (70 %) and specific in both terms of their lateralizing value and their ability to identify the L5 or S1 level. Moreover, combining SEPs and EMG significantly increased the sensitivity of the electrophysiological testing when compared with each method alone. There was no relationship between SEPs performed before surgery and surgical outcome. Inversely, we demonstrated the prognostic value of SEPs performed on Day 4. SEP normalization at Day 4 was associated with a good outcome at Day 50 in 91.8 % of examined cases, while the persistance of pathological SEPs at Day 4 was associated with poor outcome at Day 50 in 56 % of the cases.