Negative Affectivity, Depression, and Resting Heart Rate Variability (HRV) as Possible Moderators of Endogenous Pain Modulation in Functional Somatic Syndromes

Abstract

Background: Several studies have shown that patients with functional somatic syndromes (FSS) have, on average, deficient endogenous pain modulation (EPM), as well as elevated levels of negative affectivity (NA) and high comorbidity with depression and reduced resting heart rate variability (HRV) compared to healthy controls (HC). The goals of this study were (1) to replicate these findings and (2) to investigate the moderating role of NA, depression, and resting HRV in EPM efficiency within a patient group with fibromyalgia and/or chronic fatigue syndrome (CFS). Resting HRV was quantified as the root mean square of successive differences between inter-beat intervals (RMSSD) in rest, a vagally mediated time domain measure of HRV.Methods: Seventy-eight patients with fibromyalgia and/or CFS and 33 HC completed a counter-irritation paradigm as a measure of EPM efficiency. Participants rated the painfulness of electrocutaneous stimuli (of individually calibrated intensity) on the ankle before (baseline phase), during (counter-irritation phase) and after (recovery phase) the application of a cold pain stimulus on the forearm. A larger reduction in pain in the counter-irritation phase compared to the baseline phase reflects a more efficient EPM.Results: In contrast to our expectations, there was no difference between pain ratings in the baseline compared to counter-irritation phase for both patients and HC. Therefore, reliable conclusions on the moderating effect of NA, depression, and RMSSD could not be made. Surprisingly, patients reported more pain in the recovery compared to the counter-irritation and baseline phase, while HC did not. This latter effect was more pronounced in patients with comorbid depression, patients who rated the painfulness of the counter-irritation stimulus as high and patients who rated the painfulness of the electrocutaneous stimuli as low. We did not manage to successfully replicate the counter-irritation effect in HC or FSS patients. Therefore, no valid conclusions on the association between RMSSD, depression, NA and EPM efficiency can be drawn from this study. Possible reasons for the lack of the counter-irritation effect are discussed.

The Interoceptive Sensitivity and Attention Questionnaire: Evaluating Aspects of Self-Reported Interoception in Patients With Persistent Somatic Symptoms, Stress-Related Syndromes, and Healthy Controls

“…Participants in the current study were drawn from six studies, previously published or in preparation, in which patients experiencing persistent somatic symptoms and/or stress-related conditions completed the ISAQ during the recruitment phase (18,43–47) (M. Van Den Houte et al, unpublished data, 2021; I. Ramakers et al, unpublished data, 2021; M. Van Den Houte, unpublished data, 2021; K. Bogaerts et al, unpublished data, 2021). Data collection took place between 2013 and 2019.…”

“…Participants in the current study were drawn from six studies, previously published or in preparation, in which patients experiencing persistent somatic symptoms and/or stress-related conditions completed the ISAQ during the recruitment phase (18,(43)(44)(45)(46)(47)…”

Review of the Intelligent Sensor‐Memory‐Control Fusion Systems

“…Since pain is a subjective and ambiguous feeling that is differentiated from the other senses with clear physical quantities to benchmark, it is usually difficult for researchers to sense and quantify pain. Traditional methods include monitoring heart rate variability (HRV), [ 42 ] muscular electric activities, [ 43 ] electrocardiography, [ 44 ] recognition of facial expressions, skin temperature, and blood pressure to indirectly measure the pain level. With the rapid development of flexible electronic sensors in recent years, scientists have been able to directly monitor the impact of certain kinds of harmful stimuli, such as stress, temperature, and chemical substances, with either electronic or bionic means.…”

Sensor Technologies to Manage the Physiological Traits of Chronic Pain: A Review

“…A sign of ANS balance and its conditions is heart rate variability (HRV) [81][82][83][84], which refers to short-and long-term variations of heart rate due to several causes. HRV records the variation of beat-to-beat time intervals, also known as R-R intervals, as heart beats are usually associated with the R wave of the electrocardiagram (ECG) [82,85].…”