N20 amplitude can predict awakening from coma

Abstract

Introduction: To evaluate the relationship between the N20 amplitude of short-latency somatosensory evoked potentials (SSEPs) and neurologic outcomes in patients in a coma state. Methods We retrospectively enrolled neurocritical patients who were older than 18 years, admitted to the Department of Critical Medicine, Xiangya Hospital, Central South University, from Jan 2017 to Jan 2021 for 1–3 days, had a Glasgow Coma Scale (GCS) score ≤ 8, had a body temperature ≥ 35°C and had SSEP records. A good outcome was defined as a cerebral performance category (CPC) score of 1–3 at 1 year. The specificity and sensitivity of different SSEP patterns and amplitudes were calculated. Results A total of 457 patients were included in this study. An N20 amplitude > 4.53 µV predicted awakening, with a sensitivity of 29.5% and a specificity of 80% in 420 patients who had SSEPs. The N20 amplitude can be used for predicting outcomes for traumatic brain injury (TBI) (AUC = 0.70, P = 0.0077), aneurysmal subarachnoid haemorrhage (aSAH) (AUC = 0.69, P = 0.005), intracerebral haemorrhage (ICH) (AUC = 0.69, P = 0.005) and cardiac arrest (CA) (AUC = 0.72, P = 0.0077). Discussion N20 amplitude can predict awakening in patients in a coma state at 1 year. Different diseases have different cut-off values for predicting awakening.