Quantitative electroencephalographic evaluation of non-fatal and fatal traumatic coma

Area of Science:

• Neuroscience
• Neurology
• Medical Imaging

Background:

• Diffuse axonal injury (DAI) is a primary cause of death and disability following traumatic brain injury (TBI).
• Quantitative measures of cerebral function, such as electroencephalogram (EEG) and brain-stem auditory evoked potentials (BAEPs), may reflect DAI severity and predict TBI outcomes.
• Objective predictors of outcome are crucial for managing patients with severe TBI.

Purpose of the Study:

• To investigate the relationship between quantitative EEG and BAEP measures and patient outcomes after severe TBI.
• To determine if quantitative EEG and BAEP can serve as objective predictors of outcome.
• To explore the correlation between EEG measures and the histopathological severity of DAI.

Main Methods:

• Prospective study of 60 comatose patients with severe, closed head injury (Glasgow Coma Scale ≤ 8).
• Calculation of Spearman correlation coefficients (rs) for quantitative EEG (regional power, interhemispheric coherence) and BAEPs against outcomes at 6 months and 1 year.
• Examination of EEG coherence in relation to DAI severity in 10 fatalities.

Main Results:

• Left hemisphere EEG beta and alpha activity power significantly correlated with patient outcomes (P < 0.001).
• No significant correlation was found between interhemispheric EEG coherence and outcome at 6 months or 1 year.
• A significant negative correlation (rs = -0.79, P = 0.007) was observed between alpha band interhemispheric coherence and DAI severity at the temporo-occipital site in fatalities.

Conclusions:

• Regional EEG power spectra over the left hemisphere hold prognostic value for comatose patients after severe TBI.
• Interhemispheric EEG coherence did not demonstrate a reliable correlation with patient outcomes or DAI severity.
• Quantitative EEG power measures show potential as objective predictors of outcome in TBI, warranting further investigation.