Effect of Transcutaneous Acupoint Electrical Stimulation on Post-Hemorrhoidectomy-Associated Pain, Anxiety, and Heart Rate Variability: A Randomized-Controlled Study

Comparative Analysis of High-Frequency and Low-Frequency Transcutaneous Electrical Stimulation of the Right Median Nerve in the Regression of Clinical and Neurophysiological Manifestations of Generalized Anxiety Disorder

Background/Objectives: The anxiolytic effect of transcutaneous electrical nerve stimulation (TENS) is associated with the activation of endogenous inhibitory mechanisms in the central nervous system. Both low-frequency, high-amplitude TENS (LF-TENS) and high-frequency, low-amplitude TENS (HF-TENS) are capable of activating opioid, GABA, serotonin, muscarinic, and cannabinoid receptors. However, there has been no comparative analysis of the effectiveness of HF-TENS and LF-TENS in the treatment of GAD. The purpose of our research was to study the effectiveness of direct HF-TENS and LF-TENS of the right median nerve in the treatment of patients with GAD compared with sham TENS. Methods: The effectiveness of direct HF-TENS and LF-TENS of the right median nerve in the treatment of GAD was studied using Generalized Anxiety Disorder 7-item scale (GAD-7) and the Hamilton Anxiety Rating Scale (HAM-A). 40 patients underwent sham TENS, 40 patients passed HF-TENS (50 Hz-50 μs-sensory response) and 41 patients completed LF -TENS (1 Hz-200 μs-motor response) for 30 days daily. After completion of treatment, half of the patients received weekly maintenance therapy for 6 months. Electroencephalography was performed before and after treatment. Results: Our study showed that a significant reduction in the clinical symptoms of GAD as assessed by GAD-7 and HAM-A was observed after HF-TENS and LF-TENS by an average of 42.4%, and after sham stimulation only by 13.5% for at least 2 months after the end of treatment. However, LF-TENS turned out to be superior in effectiveness to HF-TENS by 51% and only on electroencephalography leads to an increase in PSD for the alpha rhythm in the occipital regions by 24% and a decrease in PSD for the beta I rhythm in the temporal and frontal regions by 28%. The prolonged effect of HF-TENS and LF-TENS was maintained without negative dynamics when TENS treatment was continued weekly throughout the entire six-month observation period. Conclusions: A prolonged anxiolytic effect of direct TENS of the right median nerve has been proven with greater regression of clinical and neurophysiological manifestations of GAD after LF-TENS compared to HF-TENS. Minimal side effects, low cost, safety, and simplicity of TENS procedures are appropriate as a home treatment modality.

Perceived Parenting Stress Is Related to Cardiac Flexibility in Mothers: Data from the NorBaby Study

Heart rate variability (HRV) is an indicator of autonomic nervous system activity, and high levels of stress and/or depressive symptoms may reduce HRV. Here, we assessed whether (a) parental stress affected HRV in mothers during the perinatal period and whether this is mediated by bonding and (b) whether antenatal maternal mental states, specifically repetitive negative thinking, depressive symptoms, and pregnancy-related anxiety, have an impact on infant HRV, and lastly, we investigated (c) the relationship between maternal HRV and infant HRV. Data are from the Northern Babies Longitudinal Study (NorBaby). In 111 parent-infant pairs, cardiac data were collected 6 months after birth. In the antenatal period, we used the Pregnancy-Related Anxiety Questionnaire-Revised, the Edinburgh Postnatal Depression Scale, and the Perseverative Thinking Questionnaire; in the postnatal period, we used the Parenting Stress Index and the Maternal Postnatal Attachment Scale. Higher levels of perceived parenting stress but not depressive symptoms were associated with lower HRV in mothers (τ = -0.146), and this relationship was not mediated by maternal bonding. Antenatal maternal mental states were not associated with infant HRV. There was no significant correlation between maternal HRV and infant HRV. Our observational data suggest that perceived stress reduces cardiac flexibility. Future studies should measure HRV and parenting stress repeatedly during the perinatal period.

Perioperative transcutaneous electrical acupoint stimulations as part of an enhanced recovery after surgery protocol for living donors undergoing nephrectomy: A randomized, controlled clinical trial

Objective

Living kidney donors (LKDs) experience perioperative anxiety. We designed the following study to evaluate the anxiolytic effect of transcutaneous electrical acupoint stimulation (TEAS) during the perioperative period in a group of LKDs undergoing laparotomy nephrectomy.

Methods

LKDs were randomly assigned to either the TEAS or control group. Participants in the TEAS group received 30min of intervention (6-15 mA, 2-100 Hz), at Yintang (EX-HN-3), bilateral Taichong (LR3) and Neiguan (PC6) one day before surgery (D₀), before induction of anesthesia (D₁) and one day after surgery (D₂). The participants in the control group received the same placement of electrodes but without electrical stimulation. Venous blood was collected before each intervention. Anxiety levels and recovery profiles were recorded.

Results

LKDs in the TEAS group had lower anxiety level than those in the control group at D₁, D₂ and three days after surgery (D₃). The percentage differences were: 33.3%, 25.0%, and 22.2%; [95% confidence interval (CI), (-55.1%, -11.6%), (-47.4%, -2.6%), and (-42.3%, -2.2%); P = 0.005, P = 0.034, and P = 0.035; respectively]. LKDs who received TEAS had better sleep quality and short-term recovery profiles than those in the control group. The plasma levels of 5-hydroxytryptamine (5-HT) and melatonin (MT) in the TEAS group were significantly higher than those in the control group at D₁ and D₂ (5-HT: P = 0.001, and P < 0.001; MT: P = 0.006, and P = 0.001). At the 3-month follow up, fewer LKDs in the TEAS group had incisional pain when compared to the control group (P = 0.032).

Conclusions

Perioperative TEAS decreased perioperative anxiety and facilitated postoperative recovery in the LKDs, and potential decreased the development of chronic pain. Trial Registration: Registered at ChiCTR2000029891, http://www.chictr.org.cn/listbycreater.aspx.

Efficacy and safety of transcutaneous electrical acupoints stimulation for preoperative anxiety in thoracoscopic surgery: study protocol for a randomised controlled trial

INTRODUCTION

Preoperative anxiety occurs at a very high rate in patients undergoing video-assisted thoracoscopic surgery (VATS). Moreover, it will result in poor mental state, more analgesic consumptions, rehabilitation delay and extra hospitalisation costs. Transcutaneous electrical acupoints stimulation (TEAS) is a convenient intervention for pain control and anxiety reduction. Nevertheless, TEAS efficacy of preoperative anxiety in VATS is unknown.

METHODS AND ANALYSIS

This single-centre randomised sham-controlled trial will be conducted in cardiothoracic surgery department of the Yueyang Hospital of Integrated Traditional Chinese and Western Medicine in China. A total of 92 eligible participants with pulmonary nodules (size ≥8 mm) who are arranged for VATS will be randomly assigned to a TEAS group and a sham TEAS (STEAS) group in a 1:1 ratio. Daily TEAS/STEAS intervention will be administered starting on 3 days before the VATS and continued once per day for three consecutive days. The primary outcome will be the generalised anxiety disorder scale score change between the day before surgery with the baseline. The secondary outcomes will include serum concentrations of 5-hydroxytryptamine, norepinephrine and gamma-aminobutyric acid, intraoperative anaesthetic consumption, time to postoperative chest tube removal, postoperative pain, and length of postoperative hospital stay. The adverse events will be recorded for safety evaluation. All data in this trial will be analysed by the SPSS V.21.0 statistical software package.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Ethics Committee of the Yueyang Hospital of Integrated Traditional Chinese and Western Medicine affiliated to Shanghai University of Traditional Chinese Medicine (approval number: 2021-023). The results of this study will be distributed through peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04895852.

Characterising the Features of 381 Clinical Studies Evaluating Transcutaneous Electrical Nerve Stimulation (TENS) for Pain Relief: A Secondary Analysis of the Meta-TENS Study to Improve Future Research

Background and Objectives: Characterising the features of methodologies, clinical attributes and intervention protocols, of studies is valuable to advise directions for research and practice. This article reports the findings of a secondary analysis of the features from studies screened as part of a large systematic review of TENS (the meta-TENS study). Materials and Methods: A descriptive analysis was performed on information associated with methodology, sample populations and intervention protocols from 381 randomised controlled trials (24,532 participants) evaluating TENS delivered at a strong comfortable intensity at the painful site in adults with pain, irrespective of diagnosis. Results: Studies were conducted in 43 countries commonly using parallel group design (n = 334) and one comparator group (n = 231). Mean ± standard deviation (SD) study sample size (64.05 ± 58.29 participants) and TENS group size (27.67 ± 21.90 participants) were small, with only 13 of 381 studies having 100 participants or more in the TENS group. Most TENS interventions were ‘high frequency’ (>10 pps, n = 276) and using 100 Hz (109/353 reports that stated a pulse frequency value). Of 476 comparator groups, 54.2% were active treatments (i.e., analgesic medication(s), exercise, manual therapies and electrophysical agents). Of 202 placebo comparator groups, 155 used a TENS device that did not deliver currents. At least 216 of 383 study groups were able to access other treatments whilst receiving TENS. Only 136 out of 381 reports included a statement about adverse events. Conclusions: Clinical studies on TENS are dominated by small parallel group evaluations of high frequency TENS that are often contaminated by concurrent treatment(s). Study reports tended focus on physiological and clinical implications rather than the veracity of methodology and findings. Previously published criteria for designing and reporting TENS studies were neglected and this should be corrected in future research using insights gleaned from this analysis.

Efficacy and Safety of Transcutaneous Electrical Acupoint Stimulation for Postoperative Pain: A Meta-Analysis of Randomized Controlled Trials

Objective

This meta-analysis aims to evaluate the effectiveness and safety of transcutaneous electrical acupoint stimulation (TEAS) in treating post-operative pain.

Methods

This meta-analysis was registered in PROSPERO (CRD42021286753). We searched PubMed, Embase, and the Cochrane Library for relevant randomized controlled trials (RCTs) about TEAS in treating postoperative pain that were published before November 2021. The primary outcome was visual analogue scale (VAS) within 24 h after surgery. The secondary outcomes included postoperative opioid analgesic drug consumption and the occurrence of adverse reactions within the postoperative 24–72 h. Adverse reactions included dizziness, nausea, and vomiting. Continuous variables were analyzed using mean difference (MDs) or standardized mean difference (SMDs) and 95% CIs. Relative risk (RR) and 95% CI were used for dichotomous data. The data were pooled and analyzed by RevMan 5.4 and STATA15.0 software.

Results

Seventeen trials with 1375 participants were included. The current results suggested that application of TEAS showed obvious superiority in reducing VAS scores (SMD = −1.51, 95% CI = −2.20∼−0.82, I2 = 96%). Subgroup analysis was performed according to open surgery and minimally invasive surgery. VAS scores were decreased after surgery at 24 h (SMD = −0.84, 95% CI = −1.07∼−0.6, I2 = 96%; SMD = −0.88, 95% CI = −1.02∼−0.75, I2 = 96%). The incidence of postoperative dizziness and nausea and vomiting was significantly lower in the TEAS group within postoperative 24–72 h (RR = 0.48, 95% CI = 0.34∼0.68, I2 = 0%; RR = 0.66, 95% CI = 0.44∼1.01, I2 = 69%; and RR = 0.49, 95% CI = 0.24∼1.00, I2 = 51%). Postoperative opioid analgesics were also reduced in the TEAS group within 72 h after surgery (SMD = −2.10, 95% CI = −3.37∼−0.82, I2 = 96%).

Conclusions

TEAS can reduce postoperative pain as well as the incidence of dizziness, nausea, and vomiting and the number of analgesics used after surgery. TEAS is a reasonable modality to incorporate into a multimodal management approach for postoperative pain.

Effects of Transcutaneous Electrical Nerve Stimulation on Mastectomy Pain, Patient Satisfaction, and Patient Outcomes

PURPOSE

Mastectomy is one of the most painful surgical procedures. Postoperative pain guidelines recommend transcutaneous electrical nerve stimulation (TENS) as a reliable non-pharmacological analgesic method. The aim of this study was to investigate the effects of TENS on postoperative pain and outcomes in patients undergoing modified radical mastectomy (MRM).

DESIGN

A single-center, single-blind, prospective, randomized-controlled study.

METHODS

This single-center, single-blind, randomized-controlled study included a total of 80 patients who underwent MRM at general surgery clinic of a tertiary center were included. The pain management of the patient outcomes were evaluated using the Turkish Revised American Pain Society Patient Outcome Questionnaire (APS-POQ-R-TR).

FINDINGS

The pain levels of the intervention group were lower than the control group. There were significant improvements in the patient outcomes such as mobilization, position, sleep, anxiety, and fear in the intervention group.

CONCLUSIONS

Our study results suggest that TENS reduces MRM pain. Thus, TENS can be recommended as a useful analgesic method in MRM.

The Effect of Progressive Relaxation Exercise on Physiological Parameters, Pain and Anxiety Levels of Patients Undergoing Colorectal Cancer Surgery: A Randomized Controlled Study

PURPOSE

This study aimed to determine the effect of progressive relaxation exercises on physiological parameters, pain, anxiety, and serum cortisol levels in patients undergoing colorectal cancer surgery.

DESIGN

This study is a randomized controlled study and has been registered at the Clinical Trial Registry Center (ID: NCT04731428).

METHODS

The study was conducted on 63 patients (experimental group = 31, control group = 32), who were scheduled for elective laparoscopic-colorectal surgery in the general surgery clinic of a university hospital in Istanbul between March 2018 and May 2019 and met the inclusion criteria. The patients in the experimental group were given progressive relaxation exercises for 15 minutes preoperatively and on postoperative days 1, 2, and 3 after breathing exercise training. The routine treatments and care process of the patients in the control group were maintained. The preoperative and postoperative pain and anxiety levels of both groups were evaluated. Blood pressure, heart rate and respiratory rate, oxygen saturation, and serum cortisol levels were measured at certain time intervals before and after the relaxation exercise.

FINDINGS

The patients in the experimental group had lower postoperative pain and anxiety levels and a lower rate of using opioid analgesic on postoperative day 0 compared to the control group. Progressive relaxation exercise had no statistically significant effect on serum cortisol or physiological parameters (P > .05).

CONCLUSIONS

Progressive relaxation exercise did not affect cortisol levels and vital signs but decreased pain and anxiety, and relatively increased tissue oxygenation, appearing an effective, safe, and practicable nursing intervention.

Acupoint stimulation improves pain and quality of life in head and neck cancer patients with chemoradiotherapy: a randomized controlled trial

Objective

This study aimed to evaluate the effect of acupoint stimulation on pain, negative moods, and quality of life for head and neck cancer (HNC) patients who underwent concurrent chemoradiotherapy (CCRT).

Methods

This randomized controlled trial recruited participants from a medical center and randomly assigned using a permuted block randomization list with computer-generated random serial numbers into the AcuCare group (n ​= ​46) receiving acupoint stimulation with transcutaneous acupoint electrical stimulation (TAES) and auricular acupressure (AA) or the control group (n ​= ​46) without any acupoint stimulation. Outcomes were repeatedly assessed pain intensity using the visual analogue scale, negative moods using the hospital anxiety and depression scale, and quality of life (QoL) using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire—Head and Neck 35.

Results

After adjusting varying mucositis grades and time-dependent growth effects, the generalized estimating equations showed a significantly increase in pain intensity at weeks 1, 2, 3, and 6 (P ​< ​0.05), but not in negative moods (P ​> ​0.05), compared to baseline and control group. Analysis of covariance showed a significant group-difference in the senses problems of QoL (F ​= ​7.33, P ​= ​0.01) at Week 6.

Conclusions

This study supports that acupoint stimulation could effectively reduce pain and improve senses problem of QoL for patients with HNC.

Trial registration

This study was registered at https://clinicaltrials.gov/NCT03640195.

Scoping review of the association between postsurgical pain and heart rate variability parameters

Supplemental Digital Content is Available in the Text. This scoping review provides some evidence of a possible association between heart rate variability and postsurgical pain, although significant variability exists among included studies.

Surgical interventions can elicit neuroendocrine and sympathovagal responses, leading to cardiac autonomic imbalance. Cardiac complications account for approximately 30% of postoperative complications. Altered heart rate variability (HRV) was initially described in the 1970s as a predictor of acute coronary syndromes and has more recently been shown to be an independent predictor of postoperative morbidity and mortality after noncardiac surgery. In general, HRV reflects autonomic balance, and altered HRV measures have been associated with anesthetic use, chronic pain conditions, and experimental pain. Despite the well-documented relationship between altered HRV and postsurgical outcomes and various pain conditions, there has not been a review of available evidence describing the association between postsurgical pain and HRV. We examined the relationship between postsurgical pain and HRV. MEDLINE and EMBASE databases were searched until December 2020 and included all studies with primary data. Two reviewers independently assessed risk of bias for each study using the criteria outlined in the Cochrane Handbook for Systematic Review of Interventions. A total of 8 studies and 1002 participants were included. Studies examined the association of postsurgical pain and HRV or analgesia nociception index derived from HRV. There was a statistically significant association between HRV measures and postsurgical pain in 6 of 8 studies. Heterogeneity of studies precluded meta-analyses. No studies reported cardiovascular outcomes. There is a potential association between postsurgical pain and HRV or analgesia nociception index, although results are likely impacted by confounding variables. Future studies are required to better delineate the relationship between postsurgical pain and HRV and impacts on cardiovascular outcomes.

Effects of perioperative transcutaneous electrical acupoint stimulation on monocytic HLA-DR expression in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass: study protocol for a double-blind randomized controlled trial

BACKGROUND

Cardiac surgery involving cardiopulmonary bypass (CPB) is known to be associated with a transient postoperative immunosuppression. When severe and persistent, this immune dysfunction predisposes patients to infectious complications, which contributes to a prolonged stay in the intensive care unit (ICU), and even mortality. Effective prevention and treatment methods are still lacking. Recent studies revealed that acupuncture-related techniques, such as electroacupuncture and transcutaneous electrical acupoint stimulation (TEAS), are able to produce effective cardioprotection and immunomodulation in adult and pediatric patients undergoing cardiac surgery with CPB, which leads to enhanced recovery. However, whether perioperative application of TEAS, a non-invasive technique, is able to improve immunosuppression of the patients with post-cardiosurgical conditions is unknown. Thus, as a preliminary study, the main objective is to evaluate the effects of TEAS on the postoperative expression of monocytic human leukocyte antigen (-D related) (mHLA-DR), a standardized "global" biomarker of injury or sepsis-associated immunosuppression, in patients receiving on-pump coronary artery bypass grafting (CABG).

METHODS

This study is a single-center clinical trial. The 88 patients scheduled to receive CABG under CPB will be randomized into two groups: the group receiving TEAS, and the group receiving transcutaneous acupoint pseudo-electric stimulation (Sham TEAS). Expression of mHLA-DR serves as a primary endpoint, and other laboratory parameters (e.g., interleukin [IL]-6, IL-10) and clinical outcomes (e.g., postoperative infectious complications, ICU stay time, and mortality) as the secondary endpoints. In addition, immune indicators, such as high mobility group box 1 protein and regulatory T cells will also be measured.

DISCUSSION

The current study is a preliminary monocentric clinical trial with a non-clinical primary endpoint, expression of mHLA-DR, aiming at determining whether perioperative application of TEAS has a potential to reverse CABG-associated immunosuppression. Although the immediate clinical impact of this study is limited, its results would inform further large-sample clinical trials using relevant patient-centered clinical outcomes as primary endpoints.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02933996. Registered on 13 October 2016.

Transcutaneous electrical acupoint stimulation for post-traumatic stress disorder: Assessor-blinded, randomized controlled study

AIM

Transcutaneous electrical acupoint stimulation (TEAS) has the potential to alleviate post-traumatic stress disorder (PTSD). The purpose of this study was to determine whether adding TEAS to sertraline or cognitive behavioral therapy (CBT) could improve the anti-PTSD efficacy.

METHODS

In this randomized controlled trial, 240 PTSD patients (60 in each group) were assigned to receive simulated TEAS combined with sertraline (group A) or with CBT (group B), active TEAS combined with CBT (group C), or active TEAS combined with CBT plus sertraline (group D) for 12 weeks. The outcomes were measured using the Clinician-Administered PTSD Scale, PTSD Check List-Civilian Version, and 17-item Hamilton Rating Scale for Depression.

RESULTS

While PTSD symptoms reduced over time in all patients, groups C and D had markedly greater improvement in both PTSD and depressive measures than groups A and B in all post-baseline measurement points, with moderate to very large effect sizes of 0.484-2.244. Groups C and D also had a significantly higher rate than groups A and B on clinical response (85.0% and 95.0% vs 63.3% and 60.0%, P < 0.001) and on remission (15.0% and 25.0% vs 3.3% and 1.7%, P < 0.001). The incidence of adverse events was similar between groups A and D and between groups B and C.

CONCLUSIONS

Additional TEAS augments the anti-PTSD and antidepressant efficacy of antidepressants or CBT, without increasing the incidence of adverse effects. TEAS could serve as an effective intervention for PTSD and comorbid depression. This trial was registered with www.chictr.org (no.: ChiCTR1800017255).

Effect of transcutaneous electrical acupoint stimulation on postoperative analgesia after ureteroscopic lithotripsy: a randomized controlled trial

Transcutaneous electrical acupoint stimulation (TEAS) is an effective analgesic measure. We studied the analgesic effect of TEAS by applying it alone after ureteroscopic lithotripsy, rather than applying it as a supplementary analgesic measure. Participants (n = 120) scheduled to undergo ureteroscopic holmium laser lithotripsy, were enrolled and randomly assigned into Group T (TEAS n = 60) and Group C (Control, n = 60). The participants in Group T were treated with TEAS for postoperative analgesia. TEAS were implemented on bilateral Shenyu (BL23) and Yinlingquan (SP9) at the time backward and the time at 4, 8, 12 h postoperatively. TEAS was re-implemented three times on the target acupoints for the next 2 days. When TEAS failed to meet the analgesic effect, the participants were given tramadol hydrochloride tablets of 100 mg. Participants of Group C were given tramadol hydrochloride tablets for postoperative analgesia. The primary outcome of VAS scores at the time backward (T₀), 4 h (T₁), 12 h (T₂), 24 h (T₃), 48 h (T₄) postoperatively and the amount of remedy for analgesic consumption within 48 h postoperatively were compared. The secondary outcome of adverse reactions and plasma concentrations of serotonin (5-HT) and substance P (SP) at T₀, T₁, T₂, T₃, T₄ were detected, respectively. The VAS scores at T₁, T₂, T₃, T₄ postoperatively in two groups were lower than T₀. Compared to group C, the VAS scores at T₁ (3.68 ± 0.68 vs. 4.79 ± 0.82, P = 0.01), T₂ (2.64 ± 0.72 vs. 3.92 ± 0.88, P = 0.03), T₃ (2.21 ± 0.88 vs. 3.38 ± 0.74, P < 0.01) in Group T were lower, and total remedy of analgesic consumption was significantly lower (127.14 ± 28.46 vs. 415.27 ± 86.37, P < 0.01) within 48 h postoperatively. The plasma concentrations of 5-HT in Group T was lower than Group C at T₁ (348.54 ± 138.49 vs. 418.69 ± 124.68, P = 0.03), T₂ (324.28 ± 112.73 vs. 398.52 ± 114.53, P < 0.01), T₄ (309.64 ± 129.09 vs. 388.46 ± 115.36, P = 0.04) postoperatively and concentrations of SP at T₁ (59.38 ± 24.68 vs. 78.93 ± 26.32, P < 0.01), T₂ (49.36 ± 25.55 vs. 66.49 ± 23.57, P = 0.02), T₃ (42.19 ± 24.36 vs. 64.15 ± 28.16, P = 0.04), T₄ (39.26 ± 19.88 vs. 54.64 ± 20.62, P = 0.02) postoperatively were also lower than Group C. Meanwhile, the occurrences of vertigo (6.7 vs. 18.3%, P < 0.01), nausea and vomiting (11.7 vs. 21.7%, P < 0.01), constipation (10.0 vs. 20.0%, P = 0.03) in Group T were also lower. Application of TEAS alone was associated with effective alleviation of postoperative pain, reduction of postoperative analgesics consumption, decrease of plasma concentration of algogenic substance and the incidence of adverse reactions after ureteroscopic lithotripsy.

Heart Rate Variability: A Novel Modality for Diagnosing Neuropathic Pain after Spinal Cord Injury

Background: Heart rate variability (HRV), the physiological variance in the heart's R-R interval length, can be analyzed to produce various parameters reflective of one's autonomic balance. HRV analysis may be used to capture those autonomic aberrations associated with chronic neuropathic pain (NP) in spinal cord injury (SCI). This study assesses the capacity of HRV parameters to diagnose NP in an SCI cohort.

Methods: An electrocardiogram (ECG) was collected at rest from able bodied participants (AB, n = 15), participants with SCI only (SCI-NP, n = 11), and those with SCI and NP (SCI+NP, n = 20). HRV parameters were analyzed using conventional time and frequency analysis.

Results: At rest, there were no heart rate differences amongst groups. However, SCI+NP participants demonstrated lower overall HRV, as determined by the SDNN time domain parameter, compared to either AB (p < 0.01) or SCI-NP (p < 0.05) groups. Moreover, AB and SCI-NP participants were statistically comparable for all HRV time and frequency domain parameters. Additional analyses demonstrated no differences in HRV parameters between T4, above vs. T5, below SCI groups (for all parameters: p > 0.15) or between C8, above vs. T1, below SCI groups (p > 0.30).

Conclusions: Participants with SCI and NP exhibit a lower overall HRV, which can be determined by HRV time domain parameter SDNN. HRV analysis is an innovative modality with the capacity for objective quantification of chronic NP in participants with SCI.