Autonomic reactivity to sensory stimulation is related to consciousness level after severe traumatic brain injury
Wijnen, V.J.M., Heutink, M., van Boxtel, G.J.M., Eilander, H.J., & de Gelder, B.
21 juni 2006Abstract
Objective:
To examine changes in the activity of the autonomic nervous system (ANS) that are related to recovery to consciousness in the
post-acute phase after severe traumatic brain injury (sTBI).
Methods:
Skin conductance and heart rate reactivity to sensory stimulation were recorded every 2 weeks for an average period of 3.5 months in 16 adolescent patients, during the assessment of their level of consciousness (LoC), and their cognitive and functional behaviour.
Results:
Both heart rate variability (HRV) and skin conductance level (SCL) in reaction to sensory stimulation changed with recovery to
consciousness. Indices of HRV and SCL that represent sympathetic activity of the autonomic nervous system (ANS) increased with recovery, whereas indices that represent parasympathetic activity decreased. In addition, we observed an increase in sympathovagal balance of the ANS with recovery.
Conclusions:
Recovery to consciousness determined by clinical observation in sTBI in the post-acute phase is related to changes in SCL and
HRV during sensory stimulation. ANS reactivity to environmental stimulation can therefore give objective supplementary information about the clinical state of sTBI patients, and can contribute to decision-making in the treatment policy of unresponsive patients.
Significance:
These findings demonstrate that autonomic reactivity can be informative concerning how a severely damaged nervous system
reacts to environmental stimulation and how, in a recovering nervous system, this reactivity changes.