Neurophysiologic diagnosis in uncooperative trauma patients: confounding factors

Median, ulnar, and posterior tibial nerve somatosensory evoked potential (SSEP) studies were performed on a total of 239 comatose or uncooperative trauma patients with head injuries. Twenty-six of those patients were suspected of having an additional spinal cord injury. One patient had more than one suspected spinal cord injury and two patients had a suspected spinal cord injury and a suspected peripheral nerve injury. Eleven of the suspected spinal cord injuries were confirmed and 13 were not confirmed by the SSEP studies. In three patients the SSEP study proved inadequate to add further information on the suspected spinal cord injury. Sixteen patients with suspected spinal cord injuries were able to cooperate with a neurologic examination approximately 6 months after injury and the SSEP findings were clinically verified in all 16 patients. Eleven patients were suspected of having an additional peripheral nerve injury. Four injuries were confirmed and seven not confirmed by the SSEP studies. Eight of those patients were able to cooperate with the follow-up neurologic examination, and the SSEP findings were clinically verified in all eight. Two patients suspected of having an additional spinal cord injury had unsuspected peripheral nerve injuries discovered by the SSEP studies. One patient was cooperative at follow-up and the SSEP findings were clinically verified. In our experience, SSEP studies have been an important diagnostic tool in the study of uncooperative trauma patients.