Western Journal of Emergency Medicine (Dec 2012)

Quantitative Brain Electrical Activity in the Initial Screening of Mild Traumatic Brain Injuries

  • Robert Chabot,
  • Roseanne Naunheim,
  • Brian O’Neil,
  • Leslie S. Prichep

Journal volume & issue
Vol. 13, no. 5
pp. 394 – 400

Abstract

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Introduction: The incidence of emergency department (ED) visits for Traumatic Brain Injury (TBI)in the United States exceeds 1,000,000 cases/year with the vast majority classified as mild (mTBI).Using existing computed tomography (CT) decision rules for selecting patients to be referred for CT,such as the New Orleans Criteria (NOC), approximately 70% of those scanned are found to havea negative CT. This study investigates the use of quantified brain electrical activity to assess itspossible role in the initial screening of ED mTBI patients as compared to NOC.Methods: We studied 119 patients who reported to the ED with mTBI and received a CT. Using ahand-held electroencephalogram (EEG) acquisition device, we collected data from frontal leadsto determine the likelihood of a positive CT. The brain electrical activity was processed off-line togenerate an index (TBI-Index, biomarker). This index was previously derived using an independentpopulation, and the value found to be sensitive for significant brain dysfunction in TBI patients. Wecompared this performance of the TBI-Index to the NOC for accuracy in prediction of positive CTfindings.Results: Both the brain electrical activity TBI-Index and the NOC had sensitivities, at 94.7% and92.1% respectively. The specificity of the TBI-Index was more than twice that of NOC, 49.4%and 23.5% respectively. The positive predictive value, negative predictive value and the positivelikelihood ratio were better with the TBI-Index. When either the TBI-Index or the NOC are positive(combining both indices) the sensitivity to detect a positive CT increases to 97%.Conclusion: The hand-held EEG device with a limited frontal montage is applicable to the EDenvironment and its performance was superior to that obtained using the New Orleans criteria.This study suggests a possible role for an index of brain function based on EEG to aid in the acuteassessment of mTBI patients.

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