MOTOR EVOKED-POTENTIALS IN THE PREOPERATIVE AND POSTOPERATIVE ASSESSMENT OF NORMAL-PRESSURE HYDROCEPHALUS

Motor evoked motor conduction time (CMCT) were examined from both uppe r and lower limbs in patients with normal pressure hydrocephalus to fi nd a predictor for the success of shunting procedures. The hypotheses that walking disturbances are due to pyramidal tract compression as we ll as the possibility that the upper limbs are affected subclinically in these patients were also studied. The study suggests that the walki ng disturbances are not the result of a major pyramidal tract dysfunct ion but probably involve the sensorimotor integration leading to norma l gait. Furthermore, CMCT measured with electromagnetic motor stimulat ion can help in selecting the patients that will benefit from shunting . The study does not provide electrophysiological evidence of upper li mb involvement in normal pressure hydrocephalus.