Heart Rate Variability for Quantification of Autonomic Dysfunction in Fibromyalgia

Reliability of Composite Autonomic Symptom Score (COMPASS)-31 in Congenital Central Hypoventilation Syndrome

RATIONALE

Congenital central hypoventilation syndrome (CCHS) is a rare disorder characterized by alveolar hypoventilation and variable autonomic nervous system (ANS) dysfunction (ANSD) due to mutations in PHOX2B, a gene crucial for ANS neural crest lineage differentiation.

OBJECTIVES AND METHODS

Our prospective study aims were twofold: to (1) assess the relationships between the subjective Composite Autonomic Symptom Score (COMPASS)-31 and objective indices of ANSD obtained from heart rate variability analyses, ambulatory blood pressure (BP) monitoring, and CO2 chemosensitivities and (2) describe the organ system ANSD, its relationship to PHOX2B genotype, and its consequences on quality of life (PedsQL) in children with CCHS.

RESULTS

Thirty-two PHOX2B mutation-confirmed subjects (median [range] age 9.2 years (4.4; 18.0), 15 girls) were enrolled. COMPASS-31 was assessed in 32 matched (sex and age, range: 4.3; 18.9 years) healthy controls. As compared to healthy controls, children with CCHS had increased vasomotor (p = 0.001), secretomotor (p = 0.021), gastrointestinal (p = 0.002) and pupillomotor (p = 0.028) scores and decreased orthostatic intolerance scores (p = 0.050). There was no difference in overall COMPASS-31 score between CCHS and controls (p = 0.083). However, in CCHS, overall COMPASS-31 scores correlated with high frequencies (HF) normalized (cardiac parasympathetic modulation: R = -0.53; p = 0.002), low frequencies (LF)/HF ratio (R = 0.56; p< 0.001), and both systolic and diastolic nighttime BP dipping (R = 0.45, p = 0.012 and R = 0.40, p = 0.028, respectively). No significant relationships between COMPASS-31 scores and chemosensitivity testing, PedsQL scores, or PHOX2B genotype were identified.

CONCLUSIONS

COMPASS-31 identified some aspects of CCHS-related ANSD, and scores correlate with objective ANS function measures, supporting the potential utility of COMPASS-31 in CCHS.

Tracking changes in autonomic function by coupled analysis of wavelet-based dispersion of heart rate variability and gastrointestinal symptom severity in individuals with hypermobile Ehlers-Danlos syndrome

Introduction

People with hypermobile Ehlers-Danlos syndrome (hEDS) experience multisystemic dysfunction with varying severity and unpredictability of flare occurrence. Cohort studies suggest that individuals with hEDS have a higher risk for autonomic dysfunction. The gold standard for assessing autonomic function, clinically, is the heart rate variability (HRV) assessment from 24-h Holter monitor electrocardiogram data, but this is expensive and can only be performed in short durations. Since their advent, biometric devices have been a non-invasive method for tracking HRV to assess autonomic function. This study aimed to understand the intra- and inter-individual variability in autonomic function and to associate this variability with gastrointestinal symptoms in individuals with hEDS using wearable devices.

Methods

We studied 122 days of biometric device data from 26 individuals, including 35 days highlighted as high gastrointestinal (GI) dysfunction and 48 days as low GI dysfunction. Utilizing wavelet analysis to assess the frequency domains of heart rate signals, we compared participants' HRV data for high, low, very low (VLF), and ultralow (ULF) frequency domains associated with physiological differences.

Results

We found a significant difference between the VLF and ULF signals on high-GI symptom days compared with low-symptoms days for 92 and 76% of the signals sampled, respectively.

Discussion

Our pilot data show a change in HRV for individuals with hEDS experiencing a flare day for a single-body system. Future research will focus on evaluating the relationship between longitudinal multisystemic symptom severity fluctuations and HRV.

Exploring Biopsychosocial Stress Markers in Women With Fibromyalgia

BACKGROUND

Identification of fibromyalgia has been a challenge for healthcare professionals due to the lack of a clinical biomarker. A well-supported integrative hypothesis holds that this condition is a chronic pain problem partly caused by long-term dysregulation of stress response. Therefore, stress assessment from a biopsychosocial perspective may be a useful approach to recognizing fibromyalgia.

PURPOSE

A cross-sectional case-control study was conducted to explore stress markers from a multidimensional perspective, including heart rate variability (as a biomarker of stress) as well as psychological distress and social stress.

METHODS

Forty-seven women with fibromyalgia were recruited from support groups and another 47 were recruited as matched pain-free controls. Comparison and discriminant function analyses were performed.

RESULTS

The data support the goodness of biopsychosocial stress markers in women with fibromyalgia, resulting in the identification of between 70% and 74.5% of fibromyalgia cases (sensitivity) and 85%-87% pain-free controls (specificity), with medium-high levels of fit (λ = 0.58 and λ = 0.59; p < .00). Women with fibromyalgia were characterized by high levels of psychological distress, social stress (disorder levels), and autonomic dysregulation. Although distress and social stress had a greater weight in discriminant functions, dysregulation in terms of low parasympathetic activity and high sympathetic activity at rest was also relevant.

CONCLUSIONS

A biopsychosocial approach to stress with an objective biomarker such as heart rate variability may be a useful tool to identify and manage FM.

Cardiac autonomic response to acute painful stimulus in individuals with chronic neck pain: A case-control study

PURPOSE

Characterize heart rate and cardiac autonomic response to painful stimulus on neck pain.

METHODS

Twenty-five individuals with neck pain and 25 healthy subjects were included. Heart rate variability and heart rate were assessed in the conditioned pain modulation test at pretest rest, during testing and in recovery. Heart rate variability indices were obtained using linear and nonlinear methods.

RESULTS

No significant differences were observed between groups regarding heart rate and the linear methods (p > 0.05). However, significant difference was observed between groups regarding nonlinear methods (standard deviation of the instantaneous variability of beat-to-beat interval variability, p = 0.005) CONCLUSIONS: Individuals with chronic neck pain showed autonomic responses similar to those of their healthy counterparts during the conditioning stimulus.

Comparative Efficacy of Neuromodulation and Structured Exercise Program on Autonomic Modulation in Fibromyalgia Patients: Pilot Study

Background: Fibromyalgia is a chronic disorder marked by widespread muscle and joint pain, persistent fatigue, sleep disturbances, and irregularities in the autonomic nervous system (ANS). Methods: This study compared the effectiveness of neuromodulation using the EXOPULSE Mollii suit with a structured exercise program in regulating ANS function in fibromyalgia patients. In this randomized, longitudinal crossover study, 10 female patients were randomly assigned to either the Suit + Exercise group or the Exercise + Suit group. Each group participated in two sessions per week for eight weeks, followed by a two-week washout period before switching to the other intervention. We measured cortical arousal, microcirculation, and heart rate variability (HRV) before and after the 1st, 8th, and 16th sessions. Results: The results showed significant improvements in cortical arousal, HRV, and microcirculation with the neuromodulation treatment whereas the exercise program only produced short-term improvements in cortical arousal. Conclusion: The EXOPULSE Mollii suit exhibited cumulative benefits on ANS modulation over time, suggesting potential long-term advantages for managing fibromyalgia. However, further research is needed to explore the delayed effects of both treatments on ANS modulation.

Composite Autonomic Symptom Score-31 for the diagnosis of cardiovascular autonomic dysfunction in long-term coronavirus disease 2019

BACKGROUND

Composite Autonomic Symptom Score-31 (COMPASS-31) is an easy-to-use screening tool for the evaluation of autonomic dysfunction in various diseases affecting neural function but has rarely been used in the assessment of long coronavirus disease 2019 (COVID-19). This study aimed to evaluate the diagnostic accuracy of the COMPASS-31 score in detecting dysfunction of the autonomic nervous system in patients 3 months after COVID-19 infection.

MATERIALS AND METHODS

Fifty-nine subjects were recruited and grouped into 2: (a) controls (n = 31) who had never had positive polymerase chain reaction results for COVID-19 before and (b) the post-COVID-19 patients (n = 28) who had confirmed COVID-19 infection 3-6 months before recruitment. COMPASS-31 questionnaire was utilized to evaluate subjective symptoms or evidence of autonomic dysfunction. Autonomic dysfunction was assessed objectively by cardiovascular autonomic reflex tests (CARTs) and heart rate variability (HRV). For comparison of quantitative variables between two groups, t-test or Mann-Whitney U test, as appropriate, were used. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), negative likelihood ratio (LR), and positive LR were used as measures of diagnostic accuracy. Receiver operating characteristic (ROC) curve analysis determined the overall accuracy of COMPASS-31.

RESULTS

The median COMPASS score was found to be significantly higher in post-COVID-19 participants than controls (15.5 vs. 10, P = 0.021). The median total CART score was also significantly higher in post-COVID-19 participants (0 vs. 1, P < 0.001). Out of 6 domains of the COMPASS score, the median value for orthostatic dysfunction was found to be significantly higher in post-COVID-19 participants than controls (12 vs. 0, P = 0.008). There was significantly fair accuracy of the COMPASS score with an area under the receiver operating curve 0.68 (0.54-0.82) following the total CART score ≥2 as the gold standard in the diagnosis of autonomic dysfunction (P = 0.021). The best cutoff point of the total COMPASS score was 12.5, where the optimal values of sensitivity, specificity, and positive and negative predictive values were achieved. Nonsignificant and weak correlations between CARTs, HRV parameters, and COMPASS score were found.

CONCLUSION

COMPASS-31 could be used as a user-friendly screening tool to detect autonomic dysfunction in post-COVID-19 cases with acceptable sensitivity and specificity.

Fibromyalgia in obstructive sleep apnea-hypopnea syndrome: a systematic review and meta-analysis

Introduction: Fibromyalgia (FM) is a common condition in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). This meta-analysis aimed to evaluate differences in sleep monitoring indicators between patients with OSAHS and positive FM and patients with OSAHS and negative FM and to determine the incidence of FM in patients with OSAHS. Methods: An exhaustive literature review was conducted to analyze the incidence of FM in patients with OSAHS, using online databases, including PubMed, EMBASE, Web of Science, CNKI, and Wanfang, both in English and Chinese. The quality of the included studies was assessed by two researchers using the Newcastle-Ottawa Scale scores. The acquired data were analyzed using Stata 11.0 software. Continuous variables were combined and analyzed using the weighted mean difference as the effect size. Conjoint analyses were performed using random-effects (I2 > 50%) or fixed-effect (I2 ≤ 50%) models based on I2 values. Results: Fourteen studies met the inclusion criteria. This study showed that 21% of patients with OSAHS experienced FM. Subgroup analyses were performed based on race, age, sex, body mass index, and diagnostic criteria for patients with OSAHS. These findings indicate that obese patients with OSAHS have a higher risk of FM, similar to females with OSAHS. Regarding most sleep monitoring indicators, there were no discernible differences between patients with OSAHS with positive FM and those with negative FM. However, patients with positive FM had marginally lower minimum arterial oxygen saturation levels than those with negative FM. The current literature suggests that patients with OSAHS have a high incidence of FM (21%), and FM has little effect on polysomnographic indicators of OSAHS. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024510786, identifier CRD42024510786.

Relation between heart rate variability and spectral analysis of electroencephalogram in chronic neuropathic pain patients

Chronic neuropathic pain (CNP) is a complex condition often arising from neural maladaptation after nerve injury. Understanding CNP complications involves the intricate interplay between brain-heart dynamics, assessed through quantitative electroencephalogram (qEEG) and heart rate variability (HRV). However, insights into their interaction in chronic pain are limited. Resting EEG and simultaneous electrocardiogram (lead II) of the participants were recorded for qEEG and HRV analysis. Correlations between HRV and qEEG parameters were calculated and compared with age, sex, and body mass index (BMI)-matched controls. CNP patients showed reduced HRV and significant increases in qEEG power spectral densities within delta, theta, and beta frequency ranges. A positive correlation was found between low frequency/ high frequency (LF/HF) ratio in HRV analysis and theta, alpha, and beta frequency bands in qEEG among CNP patients. However, no significant correlation was observed between parasympathetic indices and theta, beta bands in qEEG within CNP group, unlike age, sex, and BMI-matched healthy controls. CNP patients display significant HRV reductions and distinctive qEEG patterns. While healthy controls exhibit significant correlations between parasympathetic HRV parameters and qEEG spectral densities, these relationships are diminished or absent in CNP individuals. LF/HF ratio, reflecting sympathovagal balance, correlates significantly with qEEG frequency bands (theta, alpha, beta), illuminating autonomic dysregulation in CNP. These findings emphasize the intricate brain-heart interplay in chronic pain, warranting further exploration.

Reaction Time in Fibromyalgia Patients

BACKGROUND

Fibromyalgia has unknown aetiology and is associated with reduced information processing speed and therefore prolonged reaction time. However, the processes underlying this are unknown.

OBJECTIVES

First, to compare the reaction time in a cohort of fibromyalgia patients and a matched group of normal controls. Second, to assess whether detailed symptoms of pain and autonomic function, as well as measures of tinnitus, fatigue, daytime sleepiness and Mycoplasma pneumoniae infection are predictors of reaction time in fibromyalgia.

METHODS

The between-groups mean serial five-choice reaction time difference was assessed in a cohort of fibromyalgia patients and in a matched group of normal controls in an analytical casecontrolled study. With the mean serial five-choice reaction time as the dependent variable for the fibromyalgia group, a mixed stepwise multiple linear regression was performed with inputs relating to pain, dysautonomia, tinnitus, fatigue, daytime sleepiness and Mycoplasma pneumoniae infection.

RESULTS

The mean (standard error) serial five-choice reaction time for the fibromyalgia group was 448.4 (23.0) ms, compared with 386.3 (8.3) ms for the control group (p = 0.007). The final multiple linear regression model (p < 0.001; adjusted R2 = 0.772) contained 13 predictors: eight sensory pain and three affective pain parameters, and Mycoplasma pneumoniae IgG and IgA assay results.

CONCLUSION

Certain sensory and affective pain parameters, as well as Mycoplasma pneumoniae infection, appear to be predictors of reaction time in fibromyalgia. Further research into the pathophysiological mechanisms by which they affect information processing is warranted and may shed light on the aetiology of fibromyalgia.

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

PURPOSE

The aim of this review was to compare the heart rate variability (HRV) responses at rest of adults with chronic musculoskeletal pain against healthy controls.

METHODS

The PubMed, Scopus, Web of Science (Science and Social Science Citation Index), and CINAHL databases were searched, with no date restrictions. Two independent reviewers selected observational studies that characterized the HRV responses at rest in adults with chronic musculoskeletal pain compared with those of healthy controls. Methodological quality was assessed using the Downs and Black checklist.

RESULTS

This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. HRV in adults with chronic musculoskeletal pain was evaluated systematically. Of the 4893 studies screened, 20 of poor-to-moderate quality met the inclusion criteria. Most studies used electrocardiography and at least one time and/or frequency domain index. Studies were found that investigated HRV in adults with temporomandibular disorders, neck pain, whiplash, low back pain, and fibromyalgia. The heterogeneity of the studies in relation to painful conditions, parameters or position for HRV analysis precluded a meta-analysis. In general, these studies seem to show increased sympathetic and decreased parasympathetic modulation in adults with musculoskeletal pain when compared to controls.

CONCLUSIONS

Adults with musculoskeletal pain exhibited a decline in HRV compared to controls. However, definitive conclusions cannot be drawn since the evidence is heterogeneous and of moderate quality. Further high-quality research with standardized measurements is needed.

Assessment of autonomic symptom scales in patients with neurodevelopmental diagnoses using electronic health record data

Background

Sleep disturbances, gastrointestinal problems, and atypical heart rate are commonly observed in patients with autism spectrum disorder (ASD) and may relate to underlying function of the autonomic nervous system (ANS). The overall objective of the current study was to quantitatively characterize features of ANS function using symptom scales and available electronic health record (EHR) data in a clinically and genetically characterized pediatric cohort.

Methods

We assessed features of ANS function via chart review of patient records adapted from items drawn from a clinical research questionnaire of autonomic symptoms. This procedure coded for the presence and/or absence of targeted symptoms and was completed in 3 groups of patients, including patients with a clinical neurodevelopmental diagnosis and identified genetic etiology (NPD, n=244), those with an ASD diagnosis with no known genetic cause (ASD, n=159), and age and sex matched controls (MC, n=213). Symptoms were assessed across four main categories: (1) Mood, Behavior, and Emotion; (2) Secretomotor, Sensory Integration; (3) Urinary, Gastrointestinal, and Digestion; and (4) Circulation, Thermoregulation, Circadian function, and Sleep/Wake cycles.

Results

Chart review scores indicate an increased rate of autonomic symptoms across all four sections in our NPD group as compared to scores with ASD and/or MC. Additionally, we note several significant relationships between individual differences in autonomic symptoms and quantitative ASD traits.

Conclusion

These results highlight EHR review as a potentially useful method for quantifying variance in symptoms adapted from a questionnaire or survey. Further, using this method indicates that autonomic features are more prevalent in children with genetic disorders conferring risk for ASD and other neurodevelopmental diagnoses.

A complex interplay between autonomic symptoms and symptoms of depression, anxiety, and stress

BACKGROUND

We evaluated the influence of symptoms of depression, anxiety, and stress on the results of COMPASS-31 in a large population of people referred to the head-up tilt test (HUTT) and healthy controls (HC).

METHODS

Nine hundred fifty-nine consecutive patients referred to HUTT and 518 HC were enrolled. All participants completed Composite Autonomic Symptom Score-31 (COMPASS-31). Stress symptoms were evaluated by Depression, Anxiety, and Stress-21 (DASS-21) questionnaire. We corrected the result of the COMPASS-31 with the independent predictors in order to improve the specificity of the test.

RESULTS

In both patients and HC, COMPASS-31 was higher in participants with depression, anxiety, and stress symptoms (all p < 0.001). In a multivariable linear regression analysis, HC was negative, while female sex and symptoms of depression, anxiety, and stress were independent positive predictors of COMPASS-31. In HC, COMPASS-31 had a median of 7.913, and this value differentiated between HC and patients with a high sensitivity of 87% and low specificity of 50%. In order to adjust the value of COMPASS-31 with the parameters that were significant in the multivariable linear regression model, we calculated the new corrected COMAPSS-31 (cCOMPASS-31), which had comparable sensitivity of 77%, but an increased specificity of 73%.

CONCLUSION

This study has shown that symptoms of depression, anxiety, and/or stress worsen the perceived severity of autonomic symptoms in people with symptoms of orthostatic intolerance and healthy population. cCOMPASS-31 is a valuable tool that can help clinicians in discerning the true autonomic background of patients' complaints.

Temporomandibular disorders and autonomic dysfunction: Exploring the possible link between the two using a questionnaire survey

OBJECTIVE

To assess autonomic function and investigate factors related to its dysfunction in patients with temporomandibular disorders (TMD) from a biopsychosocial perspective.

METHODS

Seventy-six patients with TMD were investigated by clinical examination and questionnaires concerning biopsychosocial aspects (The Brief Pain Inventory, the Pain Catastrophizing Scale, and the Symptom Checklist-90-Revised) and autonomic dysfunction (The COMPASS 31).

RESULTS

Seventy-one patients were included in the study. The result of multiple regression analysis showed that four variables (sex, depression, age, and pain interference) were significantly associated with autonomic dysfunction. Increased orthostatic intolerance and bladder dysfunction were observed in females and males, respectively. Younger age was associated with higher orthostatic intolerance, while higher pain interference was associated with higher secretomotor dysfunction and bladder dysfunction. Further, higher depression scores were linked to higher scores in the gastrointestinal subdomain.

CONCLUSION

Autonomic dysfunction may affect TMD-related pain in the context of a biopsychosocial perspective.

Comparison of the Effect on Heart Rate Variability for Modeling Septoplasty and Modeling Deprivation of the Olfactory Analyzer in Rats

Modeling septoplasty and modeling sensory deprivation of the olfactory analyzer in rats were compared for the effect on the frequency domain of heart rate variability (HRV). Bulbectomy provoked more pronounced changes in HRV as compared with septoplasty simulation.

Prediction of intrapartum fever using continuously monitored vital signs and heart rate variability

Objectives

Neonatal early onset sepsis (EOS), bacterial infection during the first seven days of life, is difficult to diagnose because presenting signs are non-specific, but early diagnosis before birth can direct life-saving treatment for mother and baby. Specifically, maternal fever during labor from placental infection is the strongest predictor of EOS. Alterations in maternal heart rate variability (HRV) may precede development of intrapartum fever, enabling incipient EOS detection. The objective of this work was to build a predictive model for intrapartum fever.

Methods

Continuously measured temperature, heart rate, and beat-to-beat RR intervals were obtained from wireless sensors on women (n = 141) in labor; traditional manual vital signs were taken every 3-6 hours. Validated measures of HRV were calculated in moving 5-minute windows of RR intervals: standard deviation of normal-to-normal intervals (SDNN) and root mean square of successive differences (RMSSD) between normal heartbeats.

Results

Fever (>38.0 °C) was detected by manual or continuous measurements in 48 women. Compared to afebrile mothers, average SDNN and RMSSD in febrile mothers decreased significantly (p < 0.001) at 2 and 3 hours before fever onset, respectively. This observed HRV divergence and raw recorded vitals were applied to a logistic regression model at various time horizons, up to 4-5 hours before fever onset. Model performance increased with decreasing time horizons, and a model built using continuous vital signs as input variables consistently outperformed a model built from episodic vital signs.

Conclusions

HRV-based predictive models could identify mothers at risk for fever and infants at risk for EOS, guiding maternal antibiotic prophylaxis and neonatal monitoring.

A Systematic Review and Meta-Analysis of the Prevalence of Small Fibre Impairment in Patients with Fibromyalgia

Converging evidence shows that patients with fibromyalgia syndrome have signs of small fibre impairment, possibly leading to pain and autonomic symptoms, with a frequency that has not yet been systematically evaluated. To fill this gap, our review aims to define the frequency of somatic and autonomic small fibre damage in patients with fibromyalgia syndrome, as assessed by objective small fibre-related testing. We found 360 articles on somatic and autonomic small fibre assessment in patients with fibromyalgia. Out of the 88 articles assessed for eligibility, 20 were included in the meta-analysis, involving 903 patients with fibromyalgia. The estimated prevalence of somatic small fibre impairment, as assessed with skin biopsy, corneal confocal microscopy, and microneurography, was 49% (95% confidence interval (CI): 39–60%, I² = 89%), whereas the estimated prevalence of autonomic small fibre impairment, as assessed with heart rate variability, sympathetic skin response, skin conductance, and tilt testing, was 45% (95% CI: 25–65%, I² = 91%). Our study shows that a considerable proportion of patients with fibromyalgia have somatic and autonomic small fibre impairment, as assessed by extensive small fibre-related testing. Nevertheless, the heterogeneity and inconsistencies across studies challenge the exact role of small fibre impairment in fibromyalgia symptoms.

A comparative study of heart rate variability and physical fitness in women with moderate and severe fibromyalgia

The aim of this study was to compare the physical fitness and cardiac autonomic activity among women with moderate and severe fibromyalgia (FM) and healthy women. This study included 35 women with FM (age: 46.2±8.9 years) and 17 healthy women (age: 44.3±9.9 years). Participants with FM were divided into moderate FM (n=15) and severe FM (n=20) according to the total score obtained in FM impact questionnaire. The heart rate variability was monitored using a portable cardiac monitor with participants resting in supine position during 10 min. Thereafter, the participants performed the chair sit and reach test, the chair stand test, and the 6-min walk test to measure the lower-body flexibility, lower-body muscle strength, and cardiorespiratory fitness, respectively. The lower-body muscle strength and cardiorespiratory fitness were both reduced in moderate and severe FM compared to healthy women (P<0.01), with greater reduction in severe FM when compared to moderate FM (P<0.05). In addition, the parasympathetic indexes of heart rate variability were all similarly decreased in both moderate and severe FM, when compared to healthy women (P<0.05). The cardiac parasympathetic activity is similarly decreased in women with both moderate and severe FM in comparison to healthy women, despite a greater physical deconditioning in severe FM.

Autonomic dysfunction in amyotrophic lateral sclerosis: A neurophysiological and neurosonology study

BACKGROUND AND PURPOSE

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder affecting upper and lower motor neurons. Some ALS patients exhibit concomitant nonmotor signs, and thus ALS is considered a multisystem disorder. The aim of this study is to investigate autonomous nervous system involvement in ALS.

METHODS

We investigated 21 ALS patients and 28 age-matched controls. ALS patients were assessed for disease severity with the Revised-ALS Functional Rating Scale (ALSFSR) and for the presence of autonomic symptoms with the Composite Autonomic Symptom Score scale. Sympathetic nervous system was evaluated by sympathetic skin response (SSR) and parasympathetic nervous system by ultrasonography of vagus nerve (VN) at the level of the thyroid gland.

RESULTS

SSR latencies were shorter and SSR amplitudes were higher in controls compared to ALS patients. The cross-sectional area (CSA) of the VN was significantly smaller in ALS patients (mean CSA right/left: 1.73±0.62 mm² /1.47±0.53 mm² ) compared to controls (mean CSA right/left: 2.91±0.79 mm² /2.30±0.80 mm² ), right: p <. 001, left: p <. 001. There was a significant negative correlation between disease duration and CSA of left-VN (r = -0.493, p = .023). This correlation was attenuated between disease duration and CSA of right-VN (r = -0.419, p = .059). ALSFSR-R was positively correlated to CSA of right-VN (p = .006, r = 0.590). CSA of VN did not correlate with bulbar involvement.

CONCLUSIONS

This study confirms the presence of autonomic dysfunction in ALS patients and provides evidence of VN atrophy that correlates with disease severity and duration and is independent of bulbar involvement. Degeneration of dorsal nucleus neurons of the VN is hypothesized.

Clinical Assessment of Autonomic Function in Fibromyalgia by the Refined and Abbreviated Composite Autonomic Symptom Score (COMPASS 31): A Case-Controlled Study

BACKGROUND

It has been shown that autonomic dysfunction in fibromyalgia can be assessed by the Composite Autonomic Symptom Score (COMPASS) questionnaire. More recently, a refined and much abbreviated 31-item version of the questionnaire has been developed, the COMPASS 31.

OBJECTIVES

First, to determine whether the COMPASS 31 can assess changes in autonomic function in fibromyalgia. Second, to assess whether the COMPASS 31 values in fibromyalgia patients are positively correlated with scores on the Revised Fibromyalgia Impact Questionnaire (FIQR).

METHODS

A cross-sectional, case-controlled study was carried out with 25 fibromyalgia patients and 26 healthy controls.

RESULTS

The two groups were matched for age, sex and ethnicity, but not for body mass index (BMI). The total mean (standard error) COMPASS 31 for the fibromyalgia patients, 37.2 (1.8), differentiated the patients from the controls (9.5 (1.4); p < 0.00000001). The scores were greater in the fibromyalgia patients across all COMPASS 31 autonomic domains, namely orthostatic intolerance (p < 0.00000001), and vasomotor (p < 0.0001), secretomotor (p < 0.000001), gastrointestinal (p < 0.000001), bladder (p < 0.00001) and pupillomotor functions (p < 0.00000001). The total COMPASS 31 values were positively correlated with FIQR scores (r_s = 0.45, p < 0.05). General linear modelling of the COMPASS 31 scores showed that only group status (fibromyalgia or control) was significant (p = 3.4 × 10^-16), with age, sex and BMI being non-significant.

CONCLUSION

This study confirms that non-pain autonomic dysfunction symptoms occur in fibromyalgia and can be assessed with the COMPASS 31.

Neurophysiological and ultrasonographic comparative study of autonomous nervous system in patients suffering from fibromyalgia and generalized anxiety disorder

BACKGROUND

Fibromyalgia (FM) and generalized anxiety disorder (GAD) share common clinical features: they both affect women more than men, their diagnosis is based solely on clinical criteria, and some of the symptoms such as anxiety, aches and muscle tension, sleep disorders, and cognitive dysfunction occur in both diseases. For both conditions, an underlying dysregulation of the autonomic nervous system (ANS) has been proposed.

OBJECTIVE

The aims of this study were to investigate ANS dysfunction in FM and GAD and compare them with controls.

METHODS

Sympathetic skin response (SSR) from palm and sole and cross-sectional area (CSA) of bilateral vagus nerves (VN) were measured in 28 healthy controls, 21 FM patients, and 24 GAD patients.

RESULTS

CSA of VN was significantly smaller in FM patients (right: 1.97 ± 0.74mm², left: 1.75 ± 0.65 mm2) and GAD patients (right: 2.12 ± 0.97mm², left: 1.71 ± 0.86 mm²) compared to controls (right: 3.21 ± 0.75 mm², left: 2.65 ± 1.13 mm², p < 0.001, but did not differ between the two patient groups. SSR parameters were similar between patients and controls. SSR latency correlated to clinical scales (FM Widespread Pain Index) in the FM group (r = 0.515, p = 0.02 and r = 0.447, p = 0.05) for the upper and lower limbs respectively, but no other correlation between clinical and neurophysiological parameters was identified.

CONCLUSION

This study confirms similar ANS abnormalities in FM and GAD that fairly distinguish them from controls and support the hypothesis of a common pathophysiological substrate underlying both conditions.

A method to quantify autonomic nervous system function in healthy, able-bodied individuals

BACKGROUND

The autonomic nervous system (ANS) maintains physiological homeostasis in various organ systems via parasympathetic and sympathetic branches. ANS function is altered in common diffuse and focal conditions and heralds the beginning of environmental and disease stresses. Reliable, sensitive, and quantitative biomarkers, first defined in healthy participants, could discriminate among clinically useful changes in ANS function. This framework combines controlled autonomic testing with feature extraction during physiological responses.

METHODS

Twenty-one individuals were assessed in two morning and two afternoon sessions over two weeks. Each session included five standard clinical tests probing autonomic function: squat test, cold pressor test, diving reflex test, deep breathing, and Valsalva maneuver. Noninvasive sensors captured continuous electrocardiography, blood pressure, breathing, electrodermal activity, and pupil diameter. Heart rate, heart rate variability, mean arterial pressure, electrodermal activity, and pupil diameter responses to the perturbations were extracted, and averages across participants were computed. A template matching algorithm calculated scaling and stretching features that optimally fit the average to an individual response. These features were grouped based on test and modality to derive sympathetic and parasympathetic indices for this healthy population.

RESULTS

A significant positive correlation (p = 0.000377) was found between sympathetic amplitude response and body mass index. Additionally, longer duration and larger amplitude sympathetic and longer duration parasympathetic responses occurred in afternoon testing sessions; larger amplitude parasympathetic responses occurred in morning sessions.

CONCLUSIONS

These results demonstrate the robustness and sensitivity of an algorithmic approach to extract multimodal responses from standard tests. This novel method of quantifying ANS function can be used for early diagnosis, measurement of disease progression, or treatment evaluation.

TRIAL REGISTRATION

This study registered with Clinicaltrials.gov , identifier NCT04100486 . Registered September 24, 2019, https://www.clinicaltrials.gov/ct2/show/NCT04100486 .

Positive Relationship Between Precompetitive Sympathetic Predominance and Competitive Performance in Elite Extreme Sports Athletes

Elite athletes achieve superior performance under high pressure in competitive situations. Although it is known that such situations affect the precompetitive activity of their autonomic nervous system (ANS), the relationship between precompetitive ANS activity and performance remains controversial. Especially in extreme sports, it has been shown that cardiac sympathetic tone occurs in athletes before competition attempts. However, the relationship between precompetitive sympathetic tone and performance is unclear. To investigate this relationship in extreme sports, we organized a freestyle snowboard jumping competition and examined competitors' physiological states and performance during this event. The electrocardiograms (ECGs) of 20 elite snowboarders were measured 10 min before each jump in different competitive situations: practice, qualifying, and final sessions. The mean heart rate (HR), the low-frequency to high-frequency component ratio (LF/HF ratio), the logarithm of the HF (lnHF) component of the frequency-domain of the heart rate variability (HRV), the ratio of the standard deviation of all R-R intervals to the root mean square of successive differences of R-R intervals (SDNN/rMSSD ratio), and the rMSSD of the time-domain of the HRV were calculated from the ECG data. The results showed a significant increase in the mean HR as well as significant decreases in the lnHF component and rMSSD of the HRV as the sessions progressed. Interestingly, the mean HR, LF/HF ratio and SDNN/rMSSD ratio of the HRV showed significant positive correlations with competitive scores, and the lnHF component and rMSSD of the HRV showed significant negative correlations with the scores. Our results indicate that precompetitive ANS activity becomes predominantly sympathetic in elite extreme athletes, such as freestyle snowboarders, when the competition intensifies, and that this sympathetic predominance is positively related to competitive performance.

Differential Effects of Focused Attention and Open Monitoring Meditation on Autonomic Cardiac Modulation and Cortisol Secretion

Mindfulness-based interventions (MBIs) have been used widely as a useful tool for the alleviation of various stress-related symptoms. However, the effects of MBIs on stress-related physiological activity have not yet been ascertained. MBIs primarily consist of focused-attention (FA) and open-monitoring (OM) meditation. Since differing effects of FA and OM meditation on brain activities and cognitive tasks have been mentioned, we hypothesized that FA and OM meditation have also differing effects on stress-related physiological activity. In this study, we examined the effects of FA and OM meditation on autonomic cardiac modulation and cortisol secretion. Forty-one healthy adults (aged 20-46 years) who were meditation novices experienced 30-min FA and OM meditation tasks by listening to instructions. During resting- and meditation-states, electrocardiogram transducers were attached to participants to measure the R-R interval, which were used to evaluate heart rate (HR) and perform heart rate variability (HRV) analyses. Saliva samples were obtained from participants pre- and post-meditation to measure salivary cortisol levels. Results showed that FA meditation induced a decrease in HR and an increase in the root mean square of successive differences (rMSDD). In contrast, OM meditation induced an increase in the standard deviation of the normal-to-normal interval (SDNN) to rMSSD ratio (SDNN/rMSSD) and a decrease in salivary cortisol levels. These results suggest that FA meditation elevates physiological relaxation, whereas OM meditation elevates physiological arousal and reduces stress.

Chronic cough is associated with increased reporting of autonomic symptoms

Background

Patients with some neuronal hypersensitivity syndromes experience increased autonomic symptoms. Chronic cough is thought to be a neuronal hypersensitivity disorder and, therefore, may be associated with increased autonomic symptoms.

Methods

96 chronic cough subjects were recruited from the tertiary cough clinic based at Wythenshawe Hospital, Manchester, UK; 76 healthy controls were also recruited. Subjects were aged >18 years. Those with significant respiratory disease, significant smoking history or taking medication known to affect cough or autonomic function were excluded. Subjects completed the Composite Autonomic Symptom Score (COMPASS) 31 autonomic symptom questionnaire, the Cough Quality of Life Questionnaire (CQLQ) and a cough severity visual analogue scale (VAS).

Results

96 chronic cough subjects and 76 healthy volunteers were included in the final analysis. Mann–Whitney U-tests comparing COMPASS 31 scores in both groups showed that the total COMPASS 31 score was significantly higher in the patient group (median 18.4, interquartile range (IQR) 7.5–32.0) than the control group (median 3.6, IQR 1.1–9.5; p<0.001). The chronic cough subjects had significantly higher symptom scores than the healthy volunteer groups in all domains (p≤0.001) except vasomotor symptoms (p=0.770). There was a positive association between COMPASS 31 and CQLQ in the patient group (p<0.001, r=0.432) but not COMPASS 31 and VAS (p=0.227).

Interpretation

Chronic cough patients do indeed report more frequent and severe autonomic symptoms than healthy volunteers, indicating that this population may suffer from dysautonomia. At present, it remains unclear whether this occurs as a result of the cough or whether both the cough and dysfunction are part of some wider vagal pathology.

Chronic refractory cough patients report a greater range and severity of autonomic symptoms when compared to healthy volunteers. This may suggest that the cough is part of a wider vagal pathology.https://bit.ly/33hzJEt

Changes in the Time-Domain of Heart Rate Variability and Corticosterone after Surgical Trauma to the Nasal Septum in Rats

The aim of the work was to study changes in the time range of heart rate variability (HRV) against the background of changes in the concentration of corticosterone in blood plasma in rats after surgical trauma to the nasal septum. Septoplasty was simulated in 30 mature male Wistar rats weighing 210-290 g. ECG was recorded with subsequent analysis of the time domain of HRV, as well as blood sampling to estimate changes in the concentration of corticosterone in the blood plasma was performed. As a result, SDNN significantly increased in comparison with the control on days 2 and 3 (p < 0.001) but decreased on days 4-5 (p < 0.001) and 6 (p < 0.01). rMSSD changed in waves with two irregular peaks on days 1 and 6. SDNN/rMSSD, in comparison with the 1st day of the postoperative period, increased on the 2nd day, continued to increase (p < 0.05), and then began to decrease on day 4 (p < 0.01). The total HRV power of was low throughout the postoperative period (p < 0.001), except for day 3, when it was equal to the control data. The increase in the total power index fell on day 3 after the operation (p <0.01), after which its decline was observed again. The concentration of corticosterone in the blood plasma in rats was significantly higher than before (p < 0.001). On postoperative day 2 to 4, its plateau was determined. Simulation of septoplasty leads to changes in the time range of HRV, an increase in the concentration of corticosterone in the blood plasma in rats with its maximum at the time of surgery and 24 h later, and the formation of a "plateau" on postoperative days 2 to 4, which coincides with the changes in HRV.

Comparison of the Effects of Septoplasty and Sinus Lifting Simulation in Rats on Changes in Heart Rate Variability

The effects of septoplasty and sinus lifting simulation in rats on changes in the frequency domain of heart rate variability were compared. In the early postoperative period, the low-frequency component increases, and the high-frequency component decreases. The VLF range also increased. This indicates an increase in the activity of the sympathetic nervous system and a shift in metabolism under the influence of post-surgical inflammation.

Thermal imaging ruled out as a supplementary assessment in patients with fibromyalgia: A cross-sectional study

BACKGROUND

The diagnosis of fibromyalgia syndrome (FMS) syndrome is often complicated and relies on diagnostic criteria based mostly on the symptoms reported by patients. Implementing objective complementary tests would be desirable to better characterize this population.

OBJECTIVE

The purpose of this cross-sectional study was to compare the skin temperature at rest using thermography in women with FMS and healthy women.

METHODS

Eighty-six women with FMS and 92 healthy controls volunteered to participate. The temperature of all participants was measured by infra-red thermography, registering the skin surface temperature (minimum, maximum and average) at rest in different areas: neck, upper and lower back, chest, knees and elbows. In order to analyze the differences in the skin temperature between groups, inferential analyses of the data were performed using Mann-Whitney U test.

RESULTS

The results showed no significant difference in skin temperature between groups in the neck, upper back, chest and elbows (p>0.05). The lower back and knees areas showed significant differences between groups (p<0.05), although these differences did not reach a minimum of clinically detectable change.

CONCLUSIONS

Women with fibromyalgia presented no clinically meaningful reduction or difference in skin temperature at rest when compared with a group of healthy women. The infra-red thermography is not an effective supplementary assessment tool in women with fibromyalgia.

Exercise-related blood pressure response is related to autonomic modulation in young adults: A new extension study

BACKGROUND:

The delayed blood pressure recovery (BPR) at post-exercise has been in association with a major risk of cardiovascular disease and death.

OBJECTIVE:

The study focused on evaluating the systolic and diastolic blood pressure recovery (SBPR, DBPR) and the autonomic modulation following treadmill exercise in healthy young adults. Although considerable literature had been published about BPR and HRV, the association between BPR and ultra-short-term HRV has not yet been completely described.

METHODS:

Fifteen subjects performed exercise with three different intensities on a treadmill, the speed was 6 km/h, 9 km/h, 12 km/h, respectively. SBP and DBP was measured per 30 s in each trial. The synchronous 5-min electrocardiogram (ECG) signals were recorded and HRV30s parameters including SDNN30s, RMSSD30s, SDNN30s/RMSSD30s, SD130s, SD230s and SD130s/SD230s were calculated every 30 s periods in 5 min ECG signals to match the corresponding BPR.

RESULTS:

The intraclass correlation coefficient (ICC) values and the Bland-Altman plots indicated good consistency and repeatability between HRV30s and HRV5min at three post-exercise trials, with most ICC values > 0.75. Besides, SBPR and DBPR generally decreased and returned to the Rest level in 5 mins. The Spearman correlation coefficients showed strong relationships between BPR and HRV30s sympathetic-vagal balance parameters, i.e., ratio SDNN/RMSSD and ratio SD1/SD2.

CONCLUSIONS:

These observations represented a new insight into the cardiovascular regulation at post-exercise, which could contribute to physical exercise areas in the future.

The effects of intrinsic motivation on mental fatigue

There have been many studies attempting to disentangle the relation between motivation and mental fatigue. Mental fatigue occurs after performing a demanding task for a prolonged time, and many studies have suggested that motivation can counteract the negative effects of mental fatigue on task performance. To complicate matters, most mental fatigue studies looked exclusively at the effects of extrinsic motivation but not intrinsic motivation. Individuals are said to be extrinsically motivated when they perform a task to attain rewards and avoid punishments, while they are said to be intrinsically motivated when they do for the pleasure of doing the activity. To assess whether intrinsic motivation has similar effects as extrinsic motivation, we conducted an experiment using subjective, performance, and physiological measures (heart rate variability and pupillometry). In this experiment, 28 participants solved Sudoku puzzles on a computer for three hours, with a cat video playing in the corner of the screen. The experiment consisted of 14 blocks with two alternating conditions: low intrinsic motivation and high intrinsic motivation. The main results showed that irrespective of condition, participants reported becoming fatigued over time. They performed better, invested more mental effort physiologically, and were less distracted in high-level than in low-level motivation blocks. The results suggest that similarly to extrinsic motivation, time-on-task effects are modulated by the level of intrinsic motivation: With high intrinsic motivation, people can maintain their performance over time as they seem willing to invest more effort as time progresses than in low intrinsic motivation.

Reduced Heart Rate Variability in Patients With Medically Unexplained Physical Symptoms: A Meta-Analysis of HF-HRV and RMSSD

OBJECTIVE

Medically unexplained physical symptoms (MUPS) and related syndromes are common and place a substantial burden on both patients and society. Chronic psychological distress and dysregulation of the autonomic nervous system may be common factors associated with MUPS, although previous studies have reported mixed results. The aims of this meta-analysis are to provide an updated synthesis of studies investigating heart rate variability (HRV) indices associated with autonomic nervous system functioning in three common MUPS syndromes and to explain inconsistencies in previous study findings.

METHODS

Literature search yielded 58 studies comparing HRV indices of reduced parasympathetic activity of healthy individuals with those of patients with chronic fatigue syndrome (npatients = 271), irritable bowel syndrome (npatients = 1005), and fibromyalgia (npatients = 534). Separate random-effects meta-analyses were conducted on studies measuring root mean square of successive differences (RMSSD) and high-frequency HRV (HF-HRV).

RESULTS

Regardless of syndrome type, patients had significantly lower RMSSD (k = 22, Hedges g = -0.37 [-0.53 to -0.21], p < .001) and HF-HRV (k = 52, Hedges g = -0.69 [-1.03 to -0.36], p < .001) than did healthy individuals. Sample age and publication year explained a substantial variation in RMSSD, whereas controlling for confounders in statistical analyses explained variation in HF-HRV.

CONCLUSIONS

Lower RMSSD and HF-HRV in patients with MUPS versus healthy controls indicates that autonomic nervous system dysregulation, particularly lower parasympathetic activity, may play a role in patients with these conditions. This conclusion may have important implications for the underlying mechanisms and treatment of MUPS and related syndromes.

Cardiopulmonary Activity Monitoring Using Millimeter Wave Radars

Current cardiopulmonary activity monitoring is based on contact devices which cannot be used in extreme cases such as premature infants, burnt victims or rescue operations. In order to overcome these limitations, the use of radar technologies emerges as an alternative. This paper aims to enhance the comprehension that non-contact technologies, in particular radar techniques, offer as a monitoring tool. For this purpose, a modified low cost commercial 122 GHz frequency-modulated continuous-wave (FMCW) radar is used to better fit the current application domain. The radar signals obtained are processed using a classic linear filtering algorithm aiming to separate the breathing from the heartbeat component while preserving signals integrity. In a standoff configuration and with different subject orientations, results show that the signal obtained with the radar can be used to extract not only the respiratory and heartbeat rates, but also the heart rate variability (HRV) sequence. Moreover, results evidence the coupling between breathing and heartbeat, also showing that the HRV sequence obtained can identify the respiratory sinus arrhythmia (RSA) effect. Finally, the radar is tested in a simultaneous multi-target scenario, demonstrating its monitoring capabilities in more complex situations. Nevertheless, there are some challenges left to use the system in a real-life monitoring environments, such as the removal of random body movements.

Combination of Composite Autonomic Symptom Score 31 and Heart Rate Variability for Diagnosis of Cardiovascular Autonomic Neuropathy in People with Type 2 Diabetes

OBJECTIVE

Cardiovascular autonomic neuropathy (CAN) is a common but severe problem of diabetes, which a timely diagnosis may have important clinical implications. This study was carried out to investigate the diagnostic performance of Composite Autonomic Symptom Score 31 (COMPASS 31) combined with heart rate variability (HRV) for cardiovascular autonomic neuropathy in type 2 diabetes.

METHODS

A total of 103 hospitalized subjects with type 2 diabetes were recruited in the study. All cases received clinical data collection, laboratory examination, and related complication examinations. Cardiovascular autonomic function was assessed using CARTs, COMPASS 31, and HRV analyses. A score of at least 2 based on CARTs was defined as CAN.

RESULTS

Of the 103 subjects with type 2 diabetes, 41.8% were diagnosed with confirmed CAN. Participants with CAN had considerably higher COMPASS 31 scores. The CAN group showed a significant decrease in all HRV indices. COMPASS 31 scores and HRV indices were closely correlated with CARTs (P < 0.05). Receiver operating characteristics (ROC) curve results showed that COMPASS 31 score identified CAN with an AUC value of 0.816, while the AUC values of HRV indices were 0.648 to 0.919, among which SDNN and LF had the best diagnostic value, with the AUC values of 0.919 and 0.865, respectively. When combining COMPASS 31 score with SDNN and LF, the AUC value increased to 0.958, with a sensitivity of 90.7% and a specificity of 86.7%.

CONCLUSIONS

The combination of COMPASS 31 and HRV could improve the diagnostic performance of CAN in type 2 diabetes, which might be conducive to the diagnosis of CAN.

The Role of Motivation as a Factor in Mental Fatigue

OBJECTIVE

The aim of this study was to assess motivation as a factor in mental fatigue using subjective, performance, and physiological measures.

BACKGROUND

Sustained performance on a mentally demanding task can decrease over time. This decrement has two possible causes: a decline in available resources, meaning that performance cannot be sustained, and decrement in motivation, meaning a decline in willingness to sustain performance. However, so far, few experimental paradigms have effectively and continuously manipulated motivation, which is essential to understand its effect on mental fatigue.

METHOD

Twenty participants performed a working memory task with 14 blocks, which alternated between reward and nonreward for 2.5 hr. In the reward blocks, monetary rewards could be gained for good performance. Besides reaction time and accuracy, we used physiological measures (heart rate variability, pupil diameter, eyeblink, eye movements with a video distractor) and subjective measures of fatigue and mental effort.

RESULTS

Participants reported becoming fatigued over time and invested more mental effort in the reward blocks. Even though they reported fatigue, their accuracy in the reward blocks remained constant but declined in the nonreward blocks. Furthermore, in the nonreward blocks, participants became more distractable, invested less cognitive effort, blinked more often, and made fewer saccades. These results showed an effect of motivation on mental fatigue.

CONCLUSION

The evidence suggests that motivation is an important factor in explaining the effects of mental fatigue.

Correlation Between Chronic Neck Pain and Heart Rate Variability Indices at Rest: A Cross-sectional Study

OBJECTIVE

The purpose of this study was to correlate the heart rate variability (HRV) indices with variables of pain that were experienced by individuals with chronic neck pain.

METHODS

This was a blinded cross-sectional study. Individuals with chronic neck pain (n = 15) and healthy participants (n = 15), both sedentary and between 18 and 45 years of age, were included. The neck pain was assessed with the Numerical Rating Scale at rest and during cervical movements, Neck Disability Index, Catastrophic Thoughts about Pain Scale, and Tampa Scale of Kinesiophobia. The HRV indices (linear and nonlinear) were used for assessment of autonomic function at rest (in supine, sitting, and standing positions).

RESULTS

We observed significant correlations between the NRS, Neck Disability Index, and Catastrophic Thoughts about Pain Scale with the linear and nonlinear HRV indices (P < .05, r ≥ 0.362), so that the worst HRV indices are associated with conditions of more intense and disabling neck pain.

CONCLUSION

The HRV indices were significantly associated with pain intensity, disabilty, and catastrophizing in individuals with chronic neck pain.

Diagnostic accuracy of composite autonomic symptom scale 31 (COMPASS-31) in early detection of autonomic dysfunction in type 2 diabetes mellitus

PURPOSE

Diabetic autonomic neuropathy (DAN) is a common and disabling complication of diabetes, with cardiac autonomic neuropathy (CAN) being a major cause of mortality and morbidity. Standard autonomic function tests (AFT) are cumbersome and time consuming to conduct in OPD setting.

OBJECTIVE

To evaluate the diagnostic accuracy of composite autonomic symptom scale 31 (COMPASS-31) as a screening test for DAN.

PATIENTS AND METHODS

A cross-sectional study which enrolled 60 type 2 diabetes individuals was conducted at a tertiary care center. Autonomic functions were evaluated by COMPASS-31 questionnaire as well as by standard Ewing's battery of tests; short-term heart rate variability; sympathetic skin response along with nerve conduction studies.

RESULTS

Thirty males and 24 females completed the study. Forty-nine (89%) participants had CAN, of which, 9 (17%) had definite CAN. Peripheral neuropathy was present in 20 (37%). COMPASS-31 scores showed no difference between "No CAN" and "Early CAN". "Definite CAN" individuals differed significantly from "No and Early CAN" on COMPASS-31 scores and its gastrointestinal sub-domain. Receiver operating characteristic between "Definite CAN" and "No and Early CAN" showed fair accuracy with AUC of 0.731 (95% CI 0.561-0.901), sensitivity 77.8%, specificity 71.7% at a cut-off of 28.67 of COMPASS-31 score. Gastrointestinal sub-domain, at a cut-off score of 5.8, had 77.8% sensitivity, 60% specificity, and AUC was 0.748 (95% CI 0.603-0.894).

CONCLUSION

COMPASS-31, a self-administered tool, requiring less time, qualifies as an acceptable screening tool, especially for definite CAN. However, individuals scoring low on COMPASS-31 are still required to be evaluated by Ewing's battery to differentiate between "Early CAN" and "No CAN".

Performance of the COMPASS-31 questionnaire with regard to autonomic nervous system testing results and medication use: a prospective study in a real-life setting

The aim of this study was to investigate the performance of the Composite Autonomic System Score-31 (COMPASS-31) questionnaire in a real-life setting in consecutive patients referred to the laboratory for objective testing of the autonomic nervous system (ANS), with the hypothesis that COMPASS-31 results differ depending on medications and findings of the tilt table test results. One hundred seventy-one consecutive patients (125 females, mean age 41.5 ± 19.3) referred for testing of the ANS were enrolled. Before testing, all patients completed the recently validated Croatian version of COMPASS-31. The following data were systematically collected for all patients: age, sex, diagnoses, and medications. Results of COMPASS-31 were significantly higher in patients taking medications with a known influence on the ANS (p < 0.001). Patients with postural orthostatic tachycardia had significantly higher orthostatic intolerance and vasomotor domains of COMPASS-31 (p = 0.048 and p = 0.022, respectively). Patients with a cardiovagal score ≥ 1 had a significantly higher vasomotor domain of COMPASS-31 compared to patients with normal results of ANS tests (p = 0.030). These findings suggest the COMPASS-31 might be a valuable screening tool for autonomic dysfunctions, as it is associated with impaired ANS tests, but usage of medications that modify the ANS should always be taken into account.

The effects of slow-paced versus mechanically assisted breathing on autonomic function in fibromyalgia patients

Paced breathing has shown efficacy in fibromyalgia (FM), but the mechanisms associated with symptom change are largely unknown. We investigated whether changes in respiratory rate (RR) alone resulted in autonomic changes during normal, paced, and mechanically assisted breathing in untrained FM patients and controls. Participants included 20 FM patients and 14 controls matched for age and body mass index. During a single visit, participants completed three 15-minute breathing sessions: 1) normal breathing, 2) slow-paced breathing, and 3) mechanically assisted breathing (continuous positive airway pressure) while supine. Continuous blood pressure and electrocardiogram were recorded, and measures of heart rate variability (HRV) and spontaneous baroreceptor sensitivity (sBRS) were calculated. During normal breathing, FM patients had higher heart rate (HR), but lower HRV and sBRS variables compared to controls with no difference in RR. Compared to the paced breathing condition, FM patients had significantly lower HR with higher HRV and sBRS variables during mechanically assisted breathing, despite no significant change in RR. Mechanically assisted breathing provided greater benefits in autonomic function than paced breathing in untrained FM patients. Future research will be needed to elucidate the central pathways involved in these autonomic changes and whether training in paced breathing can eventually replicate the results seen in mechanically assisted patients.

Case report: Percutaneous electrical neural field stimulation in two cases of sympathetically-mediated pain

Background: Fibromyalgia and complex regional pain syndrome (CRPS) are both chronic pain syndromes with pathophysiologic mechanisms related to autonomic nervous system dysregulation and central sensitization.  Both syndromes are considered difficult to treat with conventional pain therapies. Case presentations: Here we describe a female veteran with fibromyalgia and a male veteran with CRPS, both of whom failed multiple pharmacologic, physical and psychological therapies for pain, but responded to percutaneous electrical neural field stimulation (PENFS) targeted at the auricular branches of the cranial nerves. Discussion: While PENFS applied to the body has been previously described for treatment of localized pain, PENFS effects on cranial nerve branches of the ear is not well-known, particularly when used for regional and full-body pain syndromes such as those described here. PENFS of the ear is a minimally-invasive, non-pharmacologic therapy that could lead to improved quality of life and decreased reliance on medication. However, further research is needed to guide clinical application, particularly in complex pain patients.

The composite autonomic symptom scale 31 is a useful screening tool for patients with Parkinsonism

Differentiation of multiple system atrophy with predominant parkinsonism (MSA-P) and Parkinson's disease (PD) is important, but an effective tool for differentiation has not been identified. We investigated the efficacy of the composite autonomic symptom scale 31 (COMPASS 31) questionnaire as a tool for evaluating autonomic function in parkinsonism patients. In this study, we enrolled drug-naïve patients with MSA-P and PD, and administered the COMPASS-31 and an objective autonomic dysfunction test (AFT). Demographic and clinical data, including parkinsonism and autonomic dysfunction, were compared between the two groups. Additionally, we determined the optimal COMPASS 31 cut-off score to differentiate MSA-P from PD for use as a screening tool. In this study, 27 MSA-P patients and 41 PD patients were recruited. The total COMPASS 31 score was well correlated with the objective AFT results. When we compared the COMPASS 31 score between the two groups, MSA-P patients showed higher total scores and sub-scores in the orthostatic intolerance, gastrointestinal, and bladder domains compared with PD patients. Similarly, MSA-P patients had more abnormalities in expiration to inspiration ratio, Valsalva ratio and pressure recovery time than PD patients in objective AFT. With 13.25 as the cut-off score for diagnosis of MSA-P, the total COMPASS-31 score demonstrated high sensitivity (92.6%) and moderate specificity (51.2%) with an area under the curve of 0.765. Based on our results, the COMPASS 31 is an effective tool for evaluation of autonomic function in patients with parkinsonism. The COMPASS-31 could be used as a sensitive and convenient screening tool, especially for the differentiation between MSA-P and PD.