[The use of evoked potentials in the follow-up and prognosis of patients in coma following severe traumatic brain injury].

INTRODUCTION

When dealing with patients in coma, it can be very useful to have early access to objective tests that provide information about their clinical status and can help to establish a prognosis for survival and functional recovery. The value of evoked potentials (EP) in such cases is already well known, although only techniques that assess the neurological status have been used.

AIM

To determine the usefulness of different types of evoked potentials as a means of reaching a short and medium term prognosis for survival and functional recovery in patients in coma as a result of traumatic brain injury (TBI).

PATIENTS AND METHODS

Our study involved patients with an admission Glasgow coma score of 8 or below due to severe TBI. During the first 24 hours the following tests were carried out on patients: somatosensory EP (SSEP), brainstem auditory EP, visual EP (VEP) obtained using stimulation goggles and mismatch negativity, as well as an imaging test (computerised axial tomography). The tests were repeated at one week and one month, and each patient was evaluated by means of the Glasgow scale and the Karnofsky scale.

RESULTS

We studied 22 patients (mean age: 39.95 years; interval: 15-84 years), 20 of them were males. The highest number of deaths occurred during the first week. There was a strong correlation between survival and the results from the SSEP and VEP.

CONCLUSIONS

SSEP and VEP performed on admission were a valuable aid for reaching a short and medium term prognosis for survival of patients in coma due to TBI, although they were not effective in evaluating a prognosis for functional recovery.