Application of evoked potentials to the prediction of discharge status in minimally responsive patients: a pilot study.

Abstract

Evoked potentials (EPs) have been shown to have useful prognostic value during the acute phase of traumatic and anoxic coma. We have hypothesized that EPs obtained in the subacute phase can be used to assess prognosis for functional recovery in minimally responsive patients with diffuse brain damage due to either brain trauma or anoxia. This pilot study correlated graded brainstem auditory evoked potentials (BAEPs) and upper extremity somatosensory evoked potentials (UESSEPs) with outcome grade based on the discharge Disability Rating Scale (DRS) score of 33 patients admitted to a responsiveness assessment program of a brain injury rehabilitation unit with an initial DRS score of 22 or greater. Results indicated a significant correlation with outcome grade for both the BAEP grade (P < .02) and the UESSEP grade (P < .02). The BAEP had a higher sensitivity and lower specificity, as false-positive exceeded false-negative predictions. The UESSEP tended to predict outcome more accurately and with a balanced number of false-positive and false-negative predictions. EPs were also found to be useful for detecting occult impairment of sensory function. This pilot study demonstrates that EPs performed near the time of admission to the rehabilitation unit can be useful in guiding the rehabilitation management of the minimally responsive patient by helping to predict functional recovery and to detect occult impairment of sensory systems.