29. ERP study in coma patients

Abstract

Introduction The prediction of functional outcome after coma remains critical issue for medical care, public health and scientific interest. Evoked potentials are widely used to assess brain function in comatose patients. Event related potentials to simplex non-vocal stimuli (MMN) are reliable in predicting an awakening, but are not sensitive to identify good recovery. In our experiment we used complex vocal stimulus: subject’s own name – SON and we investigated whether event related potentials nP3 response to SON can help to predict good functional outcome in comatose patients. Method and patients 25 comatose patients of different etiology in neurosurgical ICU Procedure: 7–10 day of coma onset: We registered auditory ERPs to the duration deviant tone burst (MMN response) and to the subject’s own name (P3 response to SON). 6–12 month of coma onset: We compared patients’ functional outcome (GOS) with presence of ERPs responses. We calculated positive a negative prognostic value. Results The positive prognostic value for good recovery (GOS > 3) is for MMN response 46% and for NP3 – SON response 88%. The negative prognostic value for good recovery is for MMN response 92% and for NP3-SON response 100%. Conclusion The presence of nP3 to SON is the strongest prognostic variable for good recovery of cognitive capacity (GOS > 3) with best positive predictive value and negative predictive value.