Predictive value of prognosis in patients with disturbance of comciousness using quantitative electroencephalography

Abstract

Objective To investigate the predictive value of prognosis of the 95% spectral edge frequency （SEF95） and total power （TP） in quantitative electroencephalography （qEEG） in patients with disturbance of consciousness. Methods The patients with disturbance of consciousness admitted in the neurointensive care unit （NICU） in Nanfang Hospital from January 2008 to June 2010 were included. Glasgow Coma Scale （GCS） scores were performed on admission and EEG monitoring was performed simultaneously. The patients were divided into either a survival goup or a death froup according to the survival status of the patients at the time of leaving NICU. The age, sex, hypertension, diabetes, GCS scores, SEF95, and TP were compared between the two groups. A multivariate logistic regression analysis was performed for the above factors. The prognostic indicators were analyzed with the receiver operating characteristic （ROC） curves and the of qEEG predictive ability of death in patients with disturbance ofconsciousness were determined. Results A total of 109 patients with supratentorial lesions were enrolled in the study, 79 of them were in the survival group and 30 of them were in the death group. The GCS scores （5 ±3 vs. 9 ±3, P =0. 000） and SEF95 （7. 0±4. 0 vs. 10. 0 ±4. 0, P = 0. 002） in the death group were significantly lower than those in the survival group. Multivariate logistic regression analysis showed that GCS scores （odds ratio 0. 100, 95% confidence interval 0. 029-0. 353） and SEF95 （odds ratio 0. 853, 95% confidence interval 0. 740-0. 983） were the independent predictors of recent prognosis. ROC curve analysis showed that the lower the GCS scores and SEF95 were, the greater the likelihood of death in patients. When SEF95 was 〈 7. 75, the sensitivity to determine the death was 60. 0%, the specificity was 72. 2%, the posi- tive predictive value was 82. 6%, and the negative predictive value was 45.0% ; when the GCS score was 〈8, the sensitivity to determine the death was 83.3%, the specificity was 73.4%, the positive predictive value was 82. 6%, and the negative predictive value was 45.0%. Conclusions SEF95 helps determine the prognosis of patients with disturbance of consciousness, and it is expected to become an important means of bedside assessment of prognosis in patients with disturbance of consciousness in NICU. Key words: Unconsciousness; Electroencephalography; Glasgow Coma Scale; Prognosis