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Associations between autonomic dysfunction and pain in chemotherapy‐induced polyneuropathy
Author(s) -
NahmanAverbuch H.,
Granovsky Y.,
Sprecher E.,
Steiner M.,
TzukShina T.,
Pud D.,
Yarnitsky D.
Publication year - 2014
Publication title -
european journal of pain
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.305
H-Index - 109
eISSN - 1532-2149
pISSN - 1090-3801
DOI - 10.1002/j.1532-2149.2013.00349.x
Subject(s) - medicine , anesthesia , valsalva maneuver , autonomic nervous system , threshold of pain , stimulus (psychology) , sensation , vagus nerve , heart rate variability , heart rate , psychology , neuroscience , stimulation , blood pressure , psychotherapist
Background Autonomic neuropathy, a relatively common complication of several chemotherapy agents, can affect the vagus nerve and its pain inhibitory capacity, thus increasing sensitivity to pain. This study aimed to evaluate the relationships between autonomic parasympathetic function and the perception of (1) spontaneous pain; (2) experimental non‐painful sensations; and (3) experimental painful sensations in chemotherapy‐induced neuropathy patients. Methods Twenty‐seven cancer patients with chemotherapy‐induced polyneuropathy were enrolled (20 women, age 56.6 ± 7.9). Autonomic parameters of heart rate variability, deep‐breathing and Valsalva ratios, experimental non‐painful parameters of warm, cold and mechanical detection thresholds, and painful parameters of heat pain thresholds, pain rating of suprathreshold stimulus, mechanical temporal summation and conditioned pain modulation response were examined. Results Autonomic parameters and spontaneous pain levels were not associated, yet autonomic parameters were positively correlated with non‐painful sensations – milder autonomic neuropathy was accompanied by milder sensory neuropathy as indicated by several parameters, e.g., lower Valsalva ratio was correlated with higher warmth detection threshold ( r = −0.465; p = 0.033). Autonomic parameters were, however, negatively correlated with painful sensations – lower parasympathetic‐vagal activity was associated with higher pain sensitivity as indicated by several parameters, e.g., lower Valsalva ratio was correlated with higher pain rating of suprathreshold stimulus ( r = −0.559; p = 0.008). Conclusions Diminished vagal function due to neuropathy is associated with, and may possibly underlie, pain disinhibition expressed as greater levels of experimental pain.