Auditory event-related potentials as indicators of good prognosis in coma of non-anoxic etiology

Abstract

The aim of this study is to evaluate whether auditory event-related potentials can predict the prognosis of recovery from coma resulting from different etiologies. The results of this study could then be used as an adjuvant test in helping the clinician evaluate patients in coma. We performed P300 auditory event-related potentials on 21 patients who developed a state of coma at our institution. We compared the results to the Glasgow coma scale at the onset of coma, on day 3, and day 21. We found that patients who developed coma secondary to cardiopulmonary arrest had no P300, and did not develop one, irrespective of their GCS, or their survival. Patients who developed coma from causes other than cardiopulmonary arrest who had a P300 at the onset of their coma, or developed one in the days that followed, ended up surviving their coma. On the other hand, patients in coma from non-cardiac causes who did not have, or developed a P300, did not survive their coma. We concluded that P300 had no prognostic value in coma secondary to anoxic brain injury, while it was an indicator of good prognosis if it was present in patients in coma from nonanoxic causes.