The brain-heart connection in disorders of consciousness
Detecting consciousness without relying on either overt behavior or asking to mentally perform a specific task is both a fundamental issue pertaining to the nature of consciousness and a clinical challenge.
The transient brain response elicited at each heartbeat captures residual consciousness in the resting-state EEG of postcomatose patients.
Brain responses to an internal bodily signal might help specify the gray zone of consciousness (i.e., the fleeting conscious feelings that are not necessarily associated with the performance of a specific task or translate into behavioral outputs).
Neural monitoring of heartbeats reflects consciousness
D. Candia-Rivera, J. Annen, O. Gosseries, C. Martial, A. Thibaut, S. Laureys and C. Tallon-Baudry (2021).
Neural responses to heartbeats detect residual signs of consciousness during resting state in post-comatose patients
Here we show that HERs in resting-state EEG data detects consciousness in postcomatose patients (unresponsive wakefulness syndrome vs minimally conscious state) with high accuracy (random forest classifier, 87% accuracy, 96% sensitivity, and 50% specificity in the validation sample).
Random EEG segments not locked to heartbeats were useful to predict unconsciousness/consciousness, but HERs were more accurate, indicating that HERs provide specific information on consciousness.
Qualitative assessment of neural responses to heartbeats in disorders of consciousness
D. Candia-Rivera and C. Machado.
Multidimensional assessment of heartbeat-evoked responses in disorders of consciousness.
European Journal of Neuroscience
https://doi.org/10.1111/ejn.16079
Clear differences in HERs and EEG non-locked to heartbeats distinguish unconscious from conscious.
We show that comparing HERs with EEG non-locked to heartbeats can be used as an additional feature when characterizing disorders of consciousness.
Minimally conscious patients distinguish different levels of auditory regularities
D. Candia-Rivera, F. Raimondo, P. Pérez, L. Naccache, C. Tallon-Baudry, J. D. Sitt.
Conscious processing of global and local auditory irregularities causes differentiated heartbeat-evoked responses
eLife
https://doi.org/10.7554/eLife.75352
The local and global effects trigger differentiated HERs allowing to distinguish between minimally conscious state and unresponsive wakefulness syndrome.
HER modulations in response to local and global auditory irregularities represent a novel neural signature of consciousness access, which may facilitate the bedside diagnosis of state of consciousness with more affordable options to neuroimaging methods.