Electroencephalographic reactivity as a predictor of prognosis in comatose patients

• DOI: 10.22533/at.ed.1593472329069

• Palavras-chave: coma, reactivity, prognosis

• Keywords: coma, reactivity, prognosis

• Abstract:

  Introduction: When vital functions are maintained, but the patient is unconscious, in a coma or in a vegetative state, it is important to predict the chance of regaining consciousness, that is, the ability to carry out simple orders or purposeful reproducible and sustained behavior. Studies suggest that the presence of reactivity on the electroencephalogram (EEG-R) predicts a greater chance of regaining consciousness. The aim of this study is to verify the prognostic value of electroencephalographic reactivity in comatose patients.
  Methods: The study included EEG of patients who were in a coma without sedation, from June 2016 to June 2017. The presence or absence of electroencephalographic reactivity was verified, and the outcome of each patient was based on the analysis of the medical records after the procedure. minimum of 2 months of follow-up. Data were descriptively analyzed using absolute and percentage frequencies, while Pearson's chi-square test was used to assess the significant association between electroencephalographic reactivity and the chance of regaining consciousness.
  Results: Of the total of 116 electroencephalographic recordings, traumatic brain injury and hemorrhagic stroke accounted for more than 50% of the causes of coma and death. The percentage that regained consciousness was 46.4% among the EEG-R and was null among the non-reactive ones (p < 0.01).
  Discussion and conclusion: Frequency, amplitude and reactivity of brain electrical activity have been demonstrated as predictors of improvement in coma. The presence of reactivity in the EEG, in this study, was not as favorable as the possibility of improvement in consciousness. However, non-reactive EEG was shown to be strongly related to a poor prognosis. Therefore, it is important to research electroencephalographic reactivity to external stimuli in comatose patients undergoing EEG, as this is a simple, useful and non-invasive method that can provide information regarding the prognosis in coma.