PRIMARY OBJECTIVE: Only a few objective prognostic markers are available for patients with disorders of consciousness (DoC). We assessed whether the magnitude of short-latency afferent inhibition (SAI) might be a useful predictor of responsiveness recovery and functional outcome in patients with DoC.
RESEARCH DESIGN: We enrolled 40 patients with prolonged Minimally Conscious State (MCS) and Unresponsive Wakefulness Syndrome (UWS) in a longitudinal, observational study.
METHODS AND PROCEDURES: Clinical features (including Coma Recovery Scale-Revised, CRS-R, and Glasgow Outcome Scale, GOS) and SAI were collected at the study entry and after 18 months from study inclusion, to assess a correlation between SAI and the clinical outcome.
MAIN OUTCOMES AND RESULTS: At the follow-up, 19 patients remained in their baseline condition, whereas 7 UWS evolved into MCS or emerged-from-MCS (EMCS), eight MCS evolved into EMCS, and two MCS- evolved into MCS+. Two UWS and one MCS+ died for cardiopulmonary complications. The patients who showed the highest GOS, the highest CRS-R and the lowest SAI strength at study entry, improved at the follow-up.
CONCLUSIONS: Our findings suggest that an objective and simple neurophysiologic measure as SAI strength could provide useful information to predict the outcome and the behavioral responsiveness of patients with DoC.