EEG of patients in coma after traumatic brain injury reflects physical parameters of auditory stimulation but not its emotional content

ABSTRACT

Primary Objective: We aimed to investigate the origin of EEG response of patients in coma and after moderate TBI to emotional stimulation, whether they distinguish emotional content or only react to the physical features of an audio signal.

Research Design: We registered EEG during continuous pleasant and unpleasant non-verbal stimulation and in rest. A total of 69 subjects participated in our study: healthy adults, conscious patients after moderate TBI and patients in coma after severe TBI. We analysed the distances between the stimuli according to EEG data and applied correlation analysis to the distances, acoustic parameters of stimuli, subjects’ emotional assessment of the stimuli, GCS score and Doppler ultrasound data.

Main Outcomes and Results: The EEG response to the stimulation in patients in coma mostly reflects the physical parameters of the stimuli, and correlated with Doppler ultrasound data. The EEG of healthy adults reflects their psychological assessment of the stimuli. Patients after moderate TBI differentiate unpleasant stimuli well and pleasant stimuli poorly, they mainly consider pitch to cope with this task like healthy adults do.

Conclusions: The reactivity to the acoustic features of emotional stimulation in patients in coma should be investigated further as a marker of patients’ recovery.

Abbreviations: TBI: traumatic brain injurym; TBI: moderate TBI; MCA: middle cerebral artery; GCS: Glasgow Coma Scale; M: mean; SD: standard deviation

KEYWORDS:

• EEG
• moderate TBI
• coma
• emotional perception

Acknowledgements

We thank the engineer of the lab Kashevarova O. and Dr Ivanitsky G. for implementing the cognitive space construction method and other technical help.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the Russian Academy of Sciences; Russian Foundation for Basic Research [16-04-00092].