Somatosensory and auditory deviance detection for outcome prediction during postanoxic coma

Abstract

ObjectiveProminent research in patients with disorders of consciousness investigated the electrophysiological correlates of auditory deviance detection as a marker of consciousness recovery. Here, we extend previous studies by investigating whether somatosensory deviance detection provides an added value for outcome prediction in postanoxic comatose patients.MethodsElectroencephalography responses to frequent and rare stimuli were obtained from 66 patients on the first and second day after coma onset.ResultsMultivariate decoding analysis revealed an above chance‐level auditory discrimination in 25 patients on the first day and in 31 patients on the second day. Tactile discrimination was significant in 16 patients on the first day and in 23 patients on the second day. Single‐day sensory discrimination was unrelated to patients’ outcome in both modalities. However, improvement of auditory discrimination from first to the second day was predictive of good outcome with a positive predictive power (PPV) of 0.73 (CI = 0.52–0.88). Analyses considering the improvement of tactile, auditory and tactile, or either auditory or tactile discrimination showed no significant prediction of good outcome (PPVs = 0.58–0.68).InterpretationOur results show that in the acute phase of coma deviance detection is largely preserved for both auditory and tactile modalities. However, we found no evidence for an added value of somatosensory to auditory deviance detection function for coma‐outcome prediction.

Evoked and Event-Related Potentials as Biomarkers of Consciousness State and Recovery

“… 52 Interestingly, based on the concept of auditory discrimination in MMN, some authors have tried to explore DOC with sensory discrimination. In the study of Pfeiffer et al, 53 patients with postanoxic DOC underwent an auditory discrimination paradigm and then a sensory discrimination paradigm. The somatosensory discrimination paradigm consisted in a vibrotactile stimulation on the left index finger (standard stimulus of 100 ms and deviant stimulus of 150 ms) presented in a pseudorandom order in two blocks with 80% of standard stimuli and 20% of deviant stimuli.…”

Automatic Sensory Predictions: A Review of Predictive Mechanisms in the Brain and Their Link to Conscious Processing

“…The vast majority of deviance studies in coma target the auditory pathway, with the exception of one study comparing auditory and somatosensory stimuli, using the same oddball paradigm ( Pfeiffer et al, 2018 ). Interestingly, this study found that discrimination between deviant and standard events at the EEG level is preserved in acute coma for both the auditory and somatosensory modalities.…”

“…Moreover, while the global effect was not in itself predictive of the patient's outcome, an improvement in decoding global standard vs. global deviant stimuli over the first 2 days of coma was informative of survival and return of consciousness (Tzovara et al, 2015). The vast majority of deviance studies in coma target the auditory pathway, with the exception of one study comparing auditory and somatosensory stimuli, using the same oddball paradigm (Pfeiffer et al, 2018). Interestingly, this study found that discrimination between deviant and standard events at the EEG level is preserved in acute coma for both the auditory and somatosensory modalities.…”

Electromyographic reactivity measured with scalp-EEG contributes to prognostication after cardiac arrest

“…Only the electrodes from the 10-20 system were considered in the present study. Recordings in Bern were performed in the context of a research project involving a mismatch negativity paradigm [20,21], after which 10 minutes of baseline EEG and then EEG during stimulations were recorded. Traces were not available to treating clinicians, however a minority of patients underwent an additional EEG shortly before or after the study EEG in case of clinical suspicion of seizures.…”