Heart rate variability in adults with chronic musculoskeletal pain: A systematic review

Nocturnal Autonomic Nervous System Dynamics and Chronic Painful Temporomandibular Disorders

OBJECTIVE

Chronic pain associated with temporomandibular disorders (TMDs) may reflect dynamic autonomic nervous system (ANS) effects. This pilot observational study tested the hypotheses that Characteristic Pain Intensity (CPI) scores correlated with 1) amplitude, 2) duration, and 3) power densities (amplitude/duration) of nocturnal ultradian cycling of the sympathetic and parasympathetic arms of the ANS.

MATERIALS AND METHODS

In accordance with institutional review board oversight and Strengthening the Reporting of Observational Studies in Epidemiology guidelines, adult subjects gave informed consent, completed Axis I and II components of Diagnostic Criteria for TMD (DC-TMD), and were trained in research protocols to record nocturnal heart rate data. Subjects were assigned to ± pain groups based on CPI scores (0 = no pain, >0 = pain). Nocturnal ultradian cycling of sympathetic and parasympathetic activities was characterized using heart rate variability measures of the percentage of the absolute value of the low-frequency power component (ms2) and normal-to-normal sinus node depolarizations >50 ms compared to total number (pNN50, %), respectively. Peaks and valleys of ultradian cycling were identified, where cycle amplitudes and durations were quantified, and sympathetic/parasympathetic power densities were calculated. The hypotheses were tested by nonparametric correlations and regression analyses, where significance was defined by P < 0.05.

RESULTS

Of 32 individuals screened and enrolled, 18 females and 11 males completed all study protocols. Subjects produced 87 nighttime electrocardiogram recordings with an average duration of 7.7 ± 1.0 h. CPI scores ranged from 0 to 70 and were significantly higher (P = 0.032) in females (30 ± 25) than in males (10 ± 17). Nocturnal ultradian sympathetic cycling in females compared to males showed significantly higher amplitudes (P = 0.011) and lower durations (P = 0.048). CPI scores were correlated with nocturnal cycling amplitude and duration (all |R| ≥ 0.80) and the log of sympathetic/parasympathetic power densities (R2 = 0.89).

CONCLUSION

Characteristic Pain Intensity scores were correlated with amplitudes, durations, and power densities of nocturnal ANS ultradian cycling.Knowledge Transfer Statement:Chronic myofascial pain may reflect autonomic nervous system (ANS) activity. Characteristic Pain Intensity scores of subjects were correlated with power densities of ANS ultradian cycling during sleep. Future research is needed to detect sex differences in ANS power densities in subjects with chronically painful temporomandibular disorders.

Impact of applying different levels of threshold-based artifact correction on the processing of heart rate variability data in individuals with temporomandibular disorder

Although heart rate variability (HRV) is a valid method to evaluate the behavior of the autonomic nervous system in individuals with temporomandibular disorder (TMD), the measurement can easily be biased by factors involving the analysis methodology, such as the removal of artifacts. Therefore, the objective of this investigation is to evaluate the impact of using different levels of threshold-based artifact correction to process HRV data in individuals with TMD. This cross-sectional observational study. Adults aged 18 to 55 years old with a diagnosis of myogenic TMD, score ≥ 50 on the Fonseca Anamnestic Index (FAI) and pain ≥ 3 on the Numerical Pain Scale (NPS) participated. The HRV was registered in the supine position (short-term) using a Polar S810i. Kubios software was used for HRV analysis using all filters. One-way ANOVA with Tukey-Kramer post-hoc was used to test the differences in HRV using the different Kubios Software artifact correction filters. The effect size was calculated based on the Cohen d. The very strong filter was statistically different (p < 0.05) compared to the no filter in all overview and time domain variables. In the frequency domain, the variables VLF, LF, HF and Total Power showed statistical differences (p < 0.05) when using the very strong filter. The same occurred with the variables SD1, SD2 and DFA α2 of the non-linear analysis (p < 0.05). The most restrictive filter of the Kubios software (very strong) significantly impacts the quantification of HRV parameters in individuals with TMD.

Effects of an arm ergometer for a patient with knee osteoarthritis and central sensitization: A case report

Aerobic exercise may be an effective treatment for knee osteoarthritis and central sensitization, but no interventional studies have examined its effects. In this study, the patient showed improvement in central sensitization, pain, and autonomic nervous system activity after aerobic exercise using an arm ergometer.

Effect of neuromodulation for chronic pain on the autonomic nervous system: a systematic review

Background

In recent years, there has been a growing interest in the use of neuromodulation as an alternative treatment option for chronic pain. Neuromodulation techniques, such as spinal cord stimulation (SCS), dorsal root ganglion (DRG) stimulation, deep brain stimulation (DBS), and peripheral nerve stimulation, have shown promising results in the management of various chronic pain conditions and involve targeted modulation of neural activity to alleviate pain and restore functional capacity. The autonomic nervous system (ANS) plays a crucial role in the regulation of various bodily functions including pain perception. However, the effects of neuromodulation on the ANS in the context of chronic pain remain poorly understood. This systematic review aimed to comprehensively assess the existing literature about the effects of neuromodulation on the ANS in chronic pain settings.

Methods

Searches were conducted using four electronic databases (PubMed, EMBASE, SCOPUS, and Web of Science). The study protocol was registered before initiation of the review process. The Office of Health Assessment and Translation (OHAT) Risk of Bias tool was used to evaluate risk of bias.

Results

A total of 43 studies were included, of which only one was an animal study. Several studies have reported more than one outcome parameter in the same population of chronic pain patients. Cardiovascular parameters were the most frequently used outcomes. More specifically, 18 outcome parameters were revealed to evaluate the function of the ANS, namely heart rate variability (n=17), arterial blood pressure (n=15), tissue oxygenation/perfusion (n=5), blood markers (n=6), multiunit postganglionic sympathetic nerve activity (n=4), skin temperature (n=3), skin conductance (n=3), cephalic autonomic symptoms (n=2), ventilatory frequency (n=2), vasomotor tone (n=1), baroreflex sensitivity (n=1), sympathetic innervation of the heart, neural activity of intrinsic cardiac neurons (n=1), vascular conductance (n=1), arterial diameter (n=1), blood pulse volume (n=1), and vagal efficiency (n=1). Most studies evaluated SCS (62.79%), followed by DBS (18.6%), peripheral nerve stimulation (9.3%), DRG stimulation (4.65%), and vagus nerve stimulation (4.65%). Overall, inconsistent results were revealed towards contribution of SCS, DBS, and peripheral nerve stimulation on ANS parameters. For DRG stimulation, included studies pointed towards a decrease in sympathetic activity.

Conclusions

There are indications that neuromodulation alters the ANS, supported by high or moderate confidence in the body of evidence, however, heterogeneity in ANS outcome measures drives towards inconclusive results. Further research is warranted to elucidate the indirect or direct mechanisms of action on the ANS, with a potential benefit for optimisation of patient selection for these interventions.

Systematic review protocol

PROSPERO (CRD42021297287).

Heart rate variability (HRV) after traumatic brain injury (TBI): a scoping review

BACKGROUND

Heart rate variability (HRV), defined as the variability between successive heart beats, is a noninvasive measure of autonomic nervous system (ANS) function, which may be altered following traumatic brain injury (TBI). This scoping review summarizes the existing literature regarding changes in HRV after TBI as well as the association between measures of HRV and outcomes following TBI.

METHODS

A literature search for articles assessing 'heart rate variability' and 'brain injury' or 'concussion' was completed. Articles were included if HRV was measured in human subjects with TBI or concussion. Review articles, protocol papers, and studies including non-traumatic injuries were excluded.

RESULTS

Sixty-three articles were included in this review. Varied methods were used to measure HRV in the different studies. Forty articles included information about differences in HRV measures after TBI and/or longitudinal changes after TBI. Fifteen studies assessed HRV and symptoms following TBI, and 15 studies assessed HRV and either functional or cognitive outcomes after TBI.

CONCLUSIONS

HRV has been studied in the context of mortality, clinical symptoms, and medical, functional, or cognitive outcomes following TBI. Methods used to measure HRV have varied amongst the different studies, which may impact findings, standardized protocols are needed for future research.