Temporary loss of intraoperative motor-evoked potential and permanent loss of somatosensory-evoked potentials associated with a postoperative sensory deficit.

We describe a case of the temporary loss of right popliteal fossa intraoperative neurogenic motor-evoked potential and the permanent loss of right median and ulnar somatosensory-evoked potentials (SSEPs) with retention of posterior tibial (SSEPs) during intramedullary spinal cord surgery in a 28-year-old man. Postoperatively, the patient had preserved motor function in all extremities and loss of proprioception, two-point discrimination, and vibration in his right upper extremity. The complementary and beneficial use of intraoperative monitoring of both motor-evoked potentials and SSEPs during spinal cord surgery is discussed.