Francesco Riganello1, Camille Chatelle2, Caroline Schnakers3, Steven Laureys4. 1. GIGA Consciousness, Coma Science Group, Liège, Belgium; Research in Advanced Neurorehabilitation (RAN), S.Anna Institute, Crotone, Italy. Electronic address: francescoriganello@gmail.com. 2. GIGA Consciousness, Coma Science Group, Liège, Belgium; Laboratory for NeuroImaging of Coma and Consciousness, Massachusetts General Hospital, Boston, Massachusetts, USA. 3. Neurosurgery Department, University of California, Los Angeles, California, USA; Research Institute, Casa Colina Hospital and Centers of Healthcare, Pomona, California, USA. 4. GIGA Consciousness, Coma Science Group, Liège, Belgium.
Abstract
CONTEXT: Heart rate variability is thought to reflect the affective and physiological aspects of pain and is emerging as a possible descriptor of the functional brain organization contributing to homeostasis. OBJECTIVES: To investigate whether the short-term Complexity Index (CIs), a measure of heart rate variability complexity is useful to discriminate responses to potentially noxious and nonnoxious stimulation in patients with different levels of consciousness. METHODS: Twenty-two patients (11 minimally conscious state [MCS], 11 vegetative state/unresponsive wakefulness syndrome [VS/UWS]) and 14 healthy controls (HC) were enrolled. We recorded the electrocardiographic response and calculated the CIs before (baseline), during, and after nonnoxious and noxious stimulation. Mann-Whitney and Wilcoxon's tests were used to investigate differences in CIs according to the level of consciousness (i.e., HC vs. patients and VS/UWS vs. MCS) and the three conditions (i.e., baseline, nonnoxious, noxious). The correlation between the three conditions and the Coma Recovery Scale-Revised was investigated by Spearman's correlations. RESULTS: We observed higher CIs values in HC as compared with patients during the baseline (P < 0.034) and after the noxious stimulation (P < 0.0001). We also found higher values in MCS versus VS/UWS patients after the noxious condition (P < 0.001) and lower values in the noxious versus nonnoxious condition solely for the VS/UWS group (P < 0.007). A correlation was found between CIs in noxious condition and Coma Recovery Scale-Revised scores. CONCLUSION: Our results suggest a less complex autonomic response to noxious stimuli in VS/UWS patients. Such method may help to better understand sympathovagal response to potentially painful stimulation in brain-injured patients.
CONTEXT: Heart rate variability is thought to reflect the affective and physiological aspects of pain and is emerging as a possible descriptor of the functional brain organization contributing to homeostasis. OBJECTIVES: To investigate whether the short-term Complexity Index (CIs), a measure of heart rate variability complexity is useful to discriminate responses to potentially noxious and nonnoxious stimulation in patients with different levels of consciousness. METHODS: Twenty-two patients (11 minimally conscious state [MCS], 11 vegetative state/unresponsive wakefulness syndrome [VS/UWS]) and 14 healthy controls (HC) were enrolled. We recorded the electrocardiographic response and calculated the CIs before (baseline), during, and after nonnoxious and noxious stimulation. Mann-Whitney and Wilcoxon's tests were used to investigate differences in CIs according to the level of consciousness (i.e., HC vs. patients and VS/UWS vs. MCS) and the three conditions (i.e., baseline, nonnoxious, noxious). The correlation between the three conditions and the Coma Recovery Scale-Revised was investigated by Spearman's correlations. RESULTS: We observed higher CIs values in HC as compared with patients during the baseline (P < 0.034) and after the noxious stimulation (P < 0.0001). We also found higher values in MCS versus VS/UWS patients after the noxious condition (P < 0.001) and lower values in the noxious versus nonnoxious condition solely for the VS/UWS group (P < 0.007). A correlation was found between CIs in noxious condition and Coma Recovery Scale-Revised scores. CONCLUSION: Our results suggest a less complex autonomic response to noxious stimuli in VS/UWS patients. Such method may help to better understand sympathovagal response to potentially painful stimulation in brain-injured patients.
Authors: Daniela Cortese; Francesco Riganello; Francesco Arcuri; Lucia Lucca; Paolo Tonin; Caroline Schnakers; Steven Laureys Journal: Front Hum Neurosci Date: 2020-04-09 Impact factor: 3.169
Authors: Krishanu Chatterjee; Mohamed Y Rady; Joseph L Verheijde; Richard J Butterfield Journal: J Intensive Care Med Date: 2021-02-22 Impact factor: 3.510