Time course of serum neuron-specific enolase - A predictor of neurologicaloutcome in patients resuscitated from cardiac arrest

Background and Purpose-The prediction of neurological outcome in comatose c ardiac arrest survivors has enormous ethical and socioeconomic implications . The purpose of the present study was to investigate the prognostic releva nce of the time course of serum neuron-specific enolase (NSE) as a biochemi cal marker of hypoxic brain damage. Methods-Serial analysis of serum NSE levels was performed in 56 patients re suscitated from witnessed, nontraumatic, normothermic, in- or out-of-hospit al cardiac arrest. The neurological outcome was evaluated with the use of t he cerebral performance category (CPC) within 6 months after restoration of spontaneous circulation (ROSC). The Mann-Whitney U test was used to compar e patients with good (CPC 1 to 2) and bad (CPC 3 to 4) neurological outcome . The diagnostic performance at different time points after ROSC was descri bed in terms of areas under receiver operating characteristic curves accord ing to standard methods. Results-Patients with a bad neurological outcome (CPC 3 to 4) had significa ntly higher NSE levels than those with a good neurological outcome at 12 (P =0.004), 24 (P=0.04), 48 (P<0.001), and 72 hours (P<0.001) after ROSC. The maximum NSE level measured within 72 hours after ROSC was also significantl y higher in patients with a bad neurological outcome (P<0.001), The NSE val ue at 72 hours after ROSC was the best predictor of neurological outcome (a rea under the curve=0.92+/-0.04). In addition, we also found a significant difference in the time course of NSE concentrations during the first 3 days after ROSC, Conclusions-Serum NSE levels are valuable adjunctive parameters for assessi ng neurological outcome after cardiac arrest.