Tracking auditory mismatch negativity responses during full conscious state and coma

Adianes Herrera-Diaz; Rober Boshra; Paniz Tavakoli; Chia-Yu A Lin; Netri Pajankar; Elham Bagheri; Richard Kolesar; Alison Fox-Robichaud; Cindy Hamielec; James P Reilly; John F Connolly

doi:10.3389/fneur.2023.1111691

Tracking auditory mismatch negativity responses during full conscious state and coma

Front Neurol. 2023 Mar 10:14:1111691. doi: 10.3389/fneur.2023.1111691. eCollection 2023.

Authors

Adianes Herrera-Diaz^{1

2}, Rober Boshra³, Paniz Tavakoli¹, Chia-Yu A Lin¹, Netri Pajankar^{1

2}, Elham Bagheri^{1

4}, Richard Kolesar⁵, Alison Fox-Robichaud^{6

7}, Cindy Hamielec^{6

7}, James P Reilly^{1

4}, John F Connolly^{1

2

4

5

8

9}

Affiliations

¹ Centre for Advanced Research in Experimental and Applied Linguistics (ARiEAL), McMaster University, Hamilton, ON, Canada.
² Neuroscience Graduate Program, McMaster University, Hamilton, ON, Canada.
³ Princenton Neuroscience Institute, Princeton University, Princeton, NJ, United States.
⁴ School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada.
⁵ Department of Anesthesia, McMaster University, Hamilton, ON, Canada.
⁶ Department of Medicine, McMaster University, Hamilton, ON, Canada.
⁷ Critical Care Medicine, Hamilton Health Sciences, Hamilton, ON, Canada.
⁸ Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, ON, Canada.
⁹ VoxNeuro, Inc., Toronto, ON, Canada.

Abstract

The mismatch negativity (MMN) is considered the electrophysiological change-detection response of the brain, and therefore a valuable clinical tool for monitoring functional changes associated with return to consciousness after severe brain injury. Using an auditory multi-deviant oddball paradigm, we tracked auditory MMN responses in seventeen healthy controls over a 12-h period, and in three comatose patients assessed over 24 h at two time points. We investigated whether the MMN responses show fluctuations in detectability over time in full conscious awareness, or whether such fluctuations are rather a feature of coma. Three methods of analysis were utilized to determine whether the MMN and subsequent event-related potential (ERP) components could be identified: traditional visual analysis, permutation t-test, and Bayesian analysis. The results showed that the MMN responses elicited to the duration deviant-stimuli are elicited and reliably detected over the course of several hours in healthy controls, at both group and single-subject levels. Preliminary findings in three comatose patients provide further evidence that the MMN is often present in coma, varying within a single patient from easily detectable to undetectable at different times. This highlights the fact that regular and repeated assessments are extremely important when using MMN as a neurophysiological predictor of coma emergence.

Keywords: brain injury; coma; disorder of consciousness; event-related potentials (ERP); mismatch negativity.

Grants and funding

This study was funded by the Collaborative Health Research Projects (CHRP) opportunity made possible by the Canadian Institutes of Health Research (CIHR; grant number CPG158287) and the Natural Sciences and Engineering Research Council of Canada (NSERC; grant number CHRP 523461-18). In-kind support toward equipment, software licences, and scientific consultation was provided by Brain Vision Solutions. In-kind support for patient identification and research assessment was provided by Hamilton Health Sciences (HHS). The design, management, analysis, and reporting of the study are entirely independent of the funders.