Continuous automated monitoring of somatosensory evoked potentials in posttraumatic coma.

Using a microcomputer system, 36 patients were continuously monitored with somatosensory evoked potentials (SSEPs) following closed head injury. The mean duration of monitoring was five days. The patients' GCS scores at the start of monitoring ranged from 3-10. Mortality was 44%. Of 14 patients who had initial absence of SSEP activity after the N20 wave or lost this activity during the period of monitoring, 12 died and two remained vegetative. Eighteen of 22 patients who had preservation or enhancement of this activity had a functional survival (3-month outcomes, p less than 0.001). The best outcomes were observed in the patients with the greatest number of peaks and highest amplitudes in the SSEPs, often in spite of increased intracranial pressure (ICP). The management of three patients was altered as a result of SSEP monitoring. We conclude that continuous monitoring of SSEPs is a useful adjunct in the management of comatose head-injured patients.