Postacute predictors of functional and cognitive progress in traumatic brain injury: Somatosensory evoked potentials

Abstract

Objective: To investigate the prognostic value of electrophysiologic studies performed during the postacute phase after traumatic brain injury (TBI). Design: A prospective comparative study in which 26 patients with TBI participated. Patients were grouped according to their admission short-latency somatosensory evoked potential (SEP) results. Nonparametric Kruskal-Wallis and Mann-Whitney U tests were applied to different SEP groups to determine the differences among them in specific functional and cognitive outcome measures. Setting: An inpatient brain injury rehabilitation unit. Participants: Twenty-six patients with TBI who were admitted to the rehabilitation center at the postacute phase for a late inpatient rehabilitation program and 15 age-matched healthy subjects who served as a control group for the electrophysiologic comparison. Main Outcome Measures: Motricity Index, Barthel Index, Disability Rating Scale, Mini-Mental Status Exam, and Rancho Los Amigos Scale. Results: Disability Rating Scale scores at discharge and rate of change of Barthel Index scores differed between median nerve SEP classification groups ( p < .05 for both). Disability Rating Scale scores at admission ( p < .05) and at discharge ( p < .01), Barthel Index scores at discharge ( p < .05), and rate of change of Barthel Index scores ( p < .05) differed between tibial nerve SEP classification groups. There was a relation between Motricity Index side scores at discharge and the different body side SEP response groups ( p < .0001). Cognitive results showed no relation to the SEP groups. Conclusions: Postacute SEP scores after a late admission to a rehabilitation center showed a relation to measures of functional and motor progress. Patients with better SEP responses were more likely to experience greater functional and motor improvement. Cognitive functions were not related to SEP results.