Autonomic dysfunction in psoriatic arthritis

The value of electrochemical skin conductance measurement by Sudoscan® for assessing autonomic dysfunction in peripheral neuropathies beyond diabetes

The diagnosis and follow-up of peripheral neuropathies involving small-diameter nerve fibers require specific examinations beyond conventional nerve conduction studies which only concern large-diameter nerve fibers. Among these tests, some are dedicated to the investigation of cutaneous innervation by the autonomic nervous system, mainly by unmyelinated sympathetic C fibers. To this end, various laboratory tests have been proposed, but the measurement of electrochemical skin conductance (ESC) by Sudoscan® is increasingly becoming the most widely used technique, because it allows a quick and simple assessment of the sudomotor function of the limb extremities. This technique is based on the principles of reverse iontophoresis and chronoamperometry and since its introduction in 2010, has been the source of nearly 200 publications. In the clinical field, most of these publications concern the evaluation of diabetic polyneuropathy, for which the value of Sudoscan® no longer needs to be demonstrated. However, there is also evidence for a role for Sudoscan® in the testing of the autonomic nervous system in various peripheral neuropathies of other origins or diseases primarily affecting the central nervous system. In this article, a comprehensive review of the literature on the clinical value of Sudoscan® outside of diabetes is presented, detailing ESC changes in neuropathies associated with various clinical conditions, such as hereditary amyloidosis or other genetic pathologies, chemotherapy neurotoxicity, dysimmune or infectious disorders, fibromyalgia, parkinsonism or other neurodegenerative diseases.

Cardiac and Sudomotor Autonomic Function in Subjects with Psoriasis With and Without Metabolic Syndrome

Purpose: Studies have shown that subjects with psoriasis (PsO) are associated with an increased risk of developing metabolic syndrome (MetS), diabetes, and cardiovascular disease. In addition, MetS and diabetes are associated with autonomic dysfunction (AD). The aim of this study was to investigate cardiac and sudomotor autonomic function in subjects with PsO and without diabetes. Methods: A cross-sectional study was performed in 20 subjects with PsO, compared with age- and sex-matched 21 healthy controls, and 20 subjects with MetS. Subjects underwent skin evaluation by dermatologist, glycated hemoglobin (HbA1c), insulin, glucose, and lipid levels, sudomotor function testing with Sudoscan^™ device (Impeto Medical, Paris, France), and cardiac autonomic function testing with ANSAR device (ANX 3.0; ANSAR Group, Inc., Philadelphia, PA). Quality of Life (QOL) and peripheral neurologic function were also assessed. Results: Participants with PsO were significantly more obese, had higher levels of fasting insulin and triglycerides, and were more insulin resistant when compared to controls. Subjects with PsO showed significantly worse cardiac autonomic function when compared to control and MetS groups. Sudomotor function and QOL scores were similar between the groups. Subgroup analysis of PsO subjects without MetS criteria (n = 15) showed persistent significantly deteriorated cardiac autonomic function when compared to the other two groups. Conclusion: This study suggests an association between PsO and cardiac AD, independent of the presence of overt dysglycemia and MetS. Additional larger studies are needed to clarify the significance of these findings and the relationship between PsO, AD, and metabolic disease.

Depression and Endothelial Dysfunction in Psoriatic Arthritis: Is There Any Possible Relationship?

Background: Cardiovascular events (CVEs) are the first cause of death in patients with psoriatic arthritis (PsA). Depression is a recognized risk factor in cardiovascular events and is frequently associated with PsA. Flow-mediated dilatation (FMD) is a widely used method for assessing endothelial dysfunction, a parameter with strong prognostic implications for CVEs. The study aims to explore the relationship between FMD, depressive symptoms and serum cytokines in a cohort of patients with PsA. Patients and Methods: FMD was assessed in 50 consecutive PsA patients aged between 30 and 75 years without known cerebrovascular and coronary heart disease or diabetes. Depressive symptoms were reported using the related subscale of the Hospital Anxiety and Depression Scale (HDS). Disease features, activity indexes, and adjusted Framingham risk score (aFRS) were calculated. Serum level of IL-6, TNF-α, and IL-17A were also assessed. Results: In PsA patients (age 50.7 ± 10.2 years, male 42%, disease duration 5.9 ± 3.3 years, Disease Activity in PSoriatic Arthritis (DAPSA) score 14.0 ± 9.4) FMD inversely correlated with the severity of depressive symptoms according to HDS (ρ = -0.339, p = 0.016), age (ρ = -0.507, p = 0.001), aFRS (rs = -0.453, p < 0.001), duration of PsA (ρ = -0.507, p = 0.001), intensity of pain (ρ = -0.507, p = 0.001), and DAPSA (ρ = -0.507, p = 0.001). No statistically significant correlation was found between FMD or HDS and serum cytokines concentrations. HDS predicted FMD in a model adjusted for age, aFRS, PsA duration, and pain intensity (β = -0.271, p = 0.008), with depressive symptoms contributing directly to 6.4% of the variance. Conclusions: Depressive symptoms correlate with endothelial dysfunction with an exposure-response pattern in our cohort of PsA patients.

Electrochemical Skin Conductance Alterations during Spinal Cord Stimulation: An Experimental Study

Despite the well-known clinical effects of spinal cord stimulation (SCS), the mechanisms of action have not yet been fully unraveled. The primary aim of this study was to measure whether electrochemical skin conductance, as a measure of peripheral sympathetic autonomic function, is altered by SCS. A second aim was to compare skin conductance levels of patients with failed back surgery syndrome (FBSS) with age- and sex-matched healthy controls. Twenty-three patients with FBSS treated with SCS participated in this study. Sudomotor function was measured with the Sudoscan^TM instrument on the hands and feet during SCS on and off states. Difference scores in skin conductance between patients and age- and sex-matched healthy controls were calculated. Normal sudomotor function at the painful lower limb was revealed for 61% of the patients when SCS was activated. Skin conductance levels were not altered between on and off states of SCS. Differences in scores between patients and healthy controls were significantly different from zero. This study showed that SCS does not influencing the sympathetic nervous system in patients with FBSS, as measured by skin conductance levels. Moreover, it suggested that there is no normalization of the functioning of the sympathetic nervous system, despite the effectiveness of SCS to reduce pain intensity.

Autoimmune Autonomic Disorders

PURPOSE OF REVIEW

Autonomic disorders sometimes occur in the context of systemic autoimmune disease or as a direct consequence of autoimmunity against the nervous system. This article provides an overview of autonomic disorders with potential autoimmune etiology.

RECENT FINDINGS

Recent evidence highlights a close association between the autonomic nervous system and inflammation. The autonomic nervous system regulates immune function, and autonomic manifestations may occur in a number of systemic autoimmune diseases. In a few instances, autoimmunity directly influences autonomic function. Autoimmune autonomic ganglionopathy is the prototypic antibody-mediated autonomic disorder. Over time, a better understanding of the clinical spectrum of autoimmune autonomic ganglionopathy, the significance of ganglionic nicotinic acetylcholine receptor antibodies, other immune-mediated autonomic neuropathies, and autonomic manifestations of other systemic or neurologic autoimmune disorders has emerged.

SUMMARY

Autoimmune autonomic disorders may be challenging, but correct identification of these conditions is important. In some cases, potential exists for effective immunomodulatory treatment.

Electrocardiographic changes in spondyloarthritis and use of anti-TNF-α drugs: a retrospective study with 100 patients

Objective

To investigate the prevalence of electrocardiographic changes in patients with spondyloarthritis and to correlate these changes with use of anti-tumor necrosis factor-alpha (TNF-α) drugs and HLA-B27 positivity.

Methods

Retrospective study including 100 patients diagnosed with spondyloarthritis according to Assessment of SpondyloArthritis International Society (ASAS) criteria and 50 controls. Epidemiological and clinical features, results of inflammatory activity tests, HLA-B27 positivity, and medication use data were extracted from medical records. Disease activity was assessed using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). All participants were submitted to electrocardiogram performed using a 12-lead device; rhythm, heart rate, conduction disorders and QT interval corrected using the Bazett formula were analyzed.

Results

Of 100 patients with spondyloarthritis, 51 were on anti-TNF-α drugs and 49 were not. HLA-B27 was detected in 53.1% of patients in the sample. Patients with spondyloarthritis had lower heart rate (p=0.06), longer QT interval (p<0.0001) and higher prevalence of right bundle branch block (p=0.014) compared to controls. Duration of disease was weakly correlated with heart rate (Rho=0.26; 95%CI: 0.06-0.44; p=0.008). The prevalence of right bundle branch block was positively correlated with HLA-B27 positivity. Use of Anti-TNF-α drugs did not interfere with electrocardiographic parameters.

Conclusion

Patients with spondyloarthritis had lower heart rate, longer QT interval and a higher prevalence of right bundle branch block compared to controls. HLA-B27 positivity was associated with the prevalence of right bundle branch block. Anti-TNF-α drugs had no impact on electrocardiographic findings.

Sudomotor function testing by electrochemical skin conductance: does it really measure sudomotor function?

OBJECTIVE

Electrochemical skin conductance (ESC) is a non-invasive test of sweat function developed as a potential marker of small fiber neuropathy. Here we systematically review the evolution of this device and the data obtained from studies of ESC across different diseases.

METHODS

Electronic databases, including MEDLINE, and Google Scholar were searched through to February 2018. The search strategy included the following terms: "electrochemical skin conductance," "EZSCAN," and "Sudoscan." The data values provided by each paper were extracted, where available, and input into tabular and figure data for direct comparison.

RESULTS

Thirty-seven studies were included this systematic review. ESC did not change by age or gender, and there was significant variability in ESC values between diseases, some of which exceeded control values. Longitudinal studies of disease demonstrated changes in ESC that were not biologically plausible. Of the 37 studies assessed, 25 received support from the device manufacturer. The extracted data did not agree with other published normative values. Prior studies do not support claims that ESC is a measure of small fiber sensory function or autonomic function.

CONCLUSIONS

Although many papers report significant differences in ESC values between disease and control subjects, the compiled data assessed in this review raises questions about the technique. Many of the published results violate biologic plausibility. A single funding source with a vested interest in the study outcomes has supported most of the studies. Normative values are inconsistent across publications, and large combined data sets do not support a high sensitivity and specificity. Finally, there is insufficient evidence supporting the claim that Sudoscan tests sudomotor or sensory nerve fiber function.

Sympathetic Nerve Hyperactivity in the Spleen: Causal for Nonpathogenic-Driven Chronic Immune-Mediated Inflammatory Diseases (IMIDs)?

Immune-Mediated Inflammatory Diseases (IMIDs) is a descriptive term coined for an eclectic group of diseases or conditions that share common inflammatory pathways, and for which there is no definitive etiology. IMIDs affect the elderly most severely, with many older individuals having two or more IMIDs. These diseases include, but are not limited to, type-1 diabetes, obesity, hypertension, chronic pulmonary disease, coronary heart disease, inflammatory bowel disease, and autoimmunity, such as rheumatoid arthritis (RA), Sjőgren's syndrome, systemic lupus erythematosus, psoriasis, psoriatic arthritis, and multiple sclerosis. These diseases are ostensibly unrelated mechanistically, but increase in frequency with age and share chronic systemic inflammation, implicating major roles for the spleen. Chronic systemic and regional inflammation underlies the disease manifestations of IMIDs. Regional inflammation and immune dysfunction promotes targeted end organ tissue damage, whereas systemic inflammation increases morbidity and mortality by affecting multiple organ systems. Chronic inflammation and skewed dysregulated cell-mediated immune responses drive many of these age-related medical disorders. IMIDs are commonly autoimmune-mediated or suspected to be autoimmune diseases. Another shared feature is dysregulation of the autonomic nervous system and hypothalamic pituitary adrenal (HPA) axis. Here, we focus on dysautonomia. In many IMIDs, dysautonomia manifests as an imbalance in activity/reactivity of the sympathetic and parasympathetic divisions of the autonomic nervous system (ANS). These major autonomic pathways are essential for allostasis of the immune system, and regulating inflammatory processes and innate and adaptive immunity. Pathology in ANS is a hallmark and causal feature of all IMIDs. Chronic systemic inflammation comorbid with stress pathway dysregulation implicate neural-immune cross-talk in the etiology and pathophysiology of IMIDs. Using a rodent model of inflammatory arthritis as an IMID model, we report disease-specific maladaptive changes in β₂-adrenergic receptor (AR) signaling from protein kinase A (PKA) to mitogen activated protein kinase (MAPK) pathways in the spleen. Beta₂-AR signal "shutdown" in the spleen and switching from PKA to G-coupled protein receptor kinase (GRK) pathways in lymph node cells drives inflammation and disease advancement. Based on these findings and the existing literature in other IMIDs, we present and discuss relevant literature that support the hypothesis that unresolvable immune stimulation from chronic inflammation leads to a maladaptive disease-inducing and perpetuating sympathetic response in an attempt to maintain allostasis. Since the role of sympathetic dysfunction in IMIDs is best studied in RA and rodent models of RA, this IMID is the primary one used to evaluate data relevant to our hypothesis. Here, we review the relevant literature and discuss sympathetic dysfunction as a significant contributor to the pathophysiology of IMIDs, and then discuss a novel target for treatment. Based on our findings in inflammatory arthritis and our understanding of common inflammatory process that are used by the immune system across all IMIDs, novel strategies to restore SNS homeostasis are expected to provide safe, cost-effective approaches to treat IMIDs, lower comorbidities, and increase longevity.

Neuromodulation in Inflammatory Skin Disease

Inflammatory skin diseases are difficult to treat because of a lack of available treatment options for severe disease. However, recent advances have shown that vagus nerve stimulation can be used to decrease inflammation and reduce disease severity in rheumatoid arthritis and inflammatory bowel disease. Changes in cytokine profiles observed in these studies are similar to those seen with use of biologics in inflammatory skin disease, suggesting that they act along similar pathways to disrupt chronic inflammation and treat inflammatory disease. This commentary explores the existing evidence demonstrating the efficacy of neuromodulation in inflammatory disease, and outlines reasons why these findings could translate to the dermatology setting to treat inflammatory skin disease.

Evidence of reduced parasympathetic autonomic regulation in inflammatory joint disease: A meta-analyses study

BACKGROUND

Rheumatoid arthritis (RA) and spondyloarthritis (SpA) are inflammatory joint disorders (IJD) with increased risk of cardiovascular disease (CVD). Autonomic dysfunction (AD) is a risk factor for CVD, and parasympathetic AD is linked to key features of IJD such as inflammation, physical inactivity and pain. Heart-rate variability (HRV) is a marker of cardiac AD. The study objective was to compare parasympathetic cardiac AD, measured by HRV, between patients with IJD and healthy controls, using meta-analysis methodology, and to examine the impact of inflammation, physical inactivity and pain on HRV in IJD.

METHODS

Medline, Embase and Amed were searched. Inclusion criteria were adult case-control studies published in English or a Scandinavian language, presenting HRV data in IJD. Two measures of HRV and 3 from the Ewing protocol were selected: square root of mean squared difference of successive R-R intervals (RMSSD), high frequency (HF), Ewing protocol; standing (E-S), breathing (E-B) and Valsalva (E-V). Patients with RA, SpA and healthy controls were compared separately using random-effects meta-analyses of standardized mean differences (SMD).

RESULTS

In all, 35 papers were eligible for inclusion. For RMSSD the pooled SMD (95% CI) RA vs. controls was -0.90 (-1.35 to -0.44), for SpA vs. controls; -0.34 (-0.73 to 0.06). For HF pooled SMD RA vs. controls was -0.78 (-0.99 to -0.57), for SpA vs. controls; -0.04 (-0.22 to 0.13). All Ewing parameters were significantly lower in cases, except for E-V which was comparable between cases and controls in patients with RA.

CONCLUSION

Patients with IJD have cardiac parasympathetic AD which is related to inflammation.

Prevalence of Autonomic Neuropathy in Patients of Rheumatoid Arthritis and Its Correlation with Disease Severity

INTRODUCTION

Autonomic Neuropathy (AN), found to be a strong predictor of sudden cardiac death, has been reported variably in patients with Rheumatoid Arthritis (RA). Manifesting as sweating disturbances, gastrointestinal irregularities, bladder or erectile dysfunction, AN can significantly affect a patient's quality of life and alter the course of the disease.

AIM

This study was undertaken to find out the prevalence and severity of AN in RA patients attending the Rheumatology Clinic at a Tertiary Care Hospital in New Delhi, India and also to investigate its correlation with patient and disease factors such as age, gender, disease severity, duration and serological status.

MATERIALS AND METHODS

In this cross-sectional study, AN was assessed subjectively by a survey of autonomic symptoms. Cardiac autonomic involvement was assessed by five cardiovascular reflex tests as described by Ewing: Heart Rate (HR) response to deep breathing, standing, and Valsalva and Blood Pressure (BP) response to standing and sustained handgrip.

RESULTS

A total of 31 RA patients and 31 age and sex matched healthy volunteers were recruited. Upon analysis it was found that the prevalence of cardiac AN was significantly higher in patients (80.65%) as compared to controls (51.61%) (p=0.016). Positive correlation with disease severity was observed with the patient reported questionnaire but not with the objective cardiovascular reflex tests. No significant correlation between grade of AN and patient's age, gender, disease duration or serological status was established.

CONCLUSION

At the end of the study, it was concluded that the pathological mechanisms responsible for autonomic dysfunction are more active in RA as compared to others.

Association of sudomotor function with peripheral artery disease in type 2 diabetes

Peripheral artery disease (PAD) is the major risk factor for cardiovascular disease and lower extremity amputation in patients with diabetes. Autonomic neuropathy is a risk factor for cardiovascular-related morbidity and mortality. Sudomotor dysfunction is well established in type 2 diabetes mellitus (T2DM) and reflects small fibre neuropathy, cardiovascular autonomic neuropathy and peripheral sympathetic autonomic neuropathy. However, the relationship between sudomotor dysfunction and PAD remains unexplored. Therefore, the aim of present study was to explore the association of sudomotor function with ankle-brachial index (ABI) and C-reactive protein (CRP) in T2DM. In this cross-sectional study, we recruited 36 consecutive type 2 diabetes patients and 20 age- and sex-matched healthy controls. Sudomotor function was assessed using Sudoscan (Sudoscan-Impeto Medical Device, EZS 01750010193, Paris, France), which detects sweat gland function through measurement of electrochemical skin conductance of both hands and feet. Measurement of ankle-brachial ABI was carried out with sphygmomanometer and Doppler device (Hadeco Bidop ES-100V3). Glycated haemoglobin (HbA1c), fasting plasma glucose, and inflammatory marker CRP were also measured. Type 2 diabetic patients had significantly impaired sudomotor function (48.14 ± 8.28 vs. 76.48 ± 6.72 µs), lower ABI (0.89 ± 0.25 vs. 1.15 ± 0.11) and elevated CRP (5.32 ± 2.41 vs. 2.45 ± 1.11 mg/l) as compared to healthy controls, respectively (p < 0.01). Sudoscan scores were found to be inversely correlated with CRP and HbA1c, and directly correlated with ABI (p < 0.05) in the patients. Sudomotor dysfunction is associated with significant peripheral artery disease, vascular inflammation and impaired glycaemic status.

Predictors of autonomic neuropathy in rheumatoid arthritis

OBJECTIVE

Autonomic dysfunction occurs in rheumatoid arthritis (RA). However, the association between the autonomic dysfunction and inflammation has not been investigated in RA. We investigated the relationship between inflammation and ANS function in RA.

METHODS

In this cross-sectional study, 25 RA patients and 25 age and sex-matched healthy controls were recruited. Autonomic function assessed by five cardiovascular reflex tests according to Ewing. Parasympathetic dysfunction established by applying three tests: heart rate response to deep breath (HRD) and standing (HRS) and Valsalva tests. Sympathetic dysfunction examined by applying two tests: BP response to standing and handgrip test. Peripheral sympathetic autonomic function assessed by Sudoscan through measurement of electrochemical skin conductance of hands and feet. Sudoscan investigates the sweat gland activity and used as a surrogate to study the damage of sympathetic sudomotor nerves in neuropathy. It is an indirect assessment tool of sudomotor function. Disease-specific and inflammatory measures (DAS 28, ESR, CRP, TNF-α, IL-6 and IL-1) were determined.

RESULTS

RA patients had significantly impaired HRD, HRS, BP response to hand grip and sudomotor function as compared to healthy controls. Pro-inflammatory cytokines were significantly higher in RA as compared to healthy controls (p<0.05). DAS 28 significantly correlated with HRD in RA. ESR significantly correlated with HRD and HRS. TNF-α significantly correlated with HRD, HRS, BP response to standing and sudomotor function. Significant correlation was found between IL-6 and HRS. Seropositive patients had more pronounced CAN and sudomotor dysfunction.

CONCLUSION

Autonomic dysfunction in RA is related to disease activity, seropositivity and pro-inflammatory cytokines.

Disease-modifying antirheumatic drugs improve cardiovascular autonomic neuropathy in psoriatic arthritis

BACKGROUND

Cardiovascular autonomic neuropathy (CAN) is a significant risk predictor for sudden cardiac death in autoimmune rheumatic diseases. As yet, there is no therapeutic treatment of CAN in psoriatic arthritis (PsA). Even now, the impact of the most commonly employed disease-modifying antirheumatic drug (DMARD) therapy on CAN in PsA is not known. Hence, we investigated the impact of DMARDs on CAN in PsA.

METHODS

In this prospective, cross-sectional study, 20 patients of PsA and 20 age- and sex-matched healthy controls were recruited. CAN was diagnosed by applying the five cardiovascular reflex tests according to Ewing. Parasympathetic dysfunction was established by performing three tests: heart-rate response to deep breathing, standing, and Valsalva tests. Sympathetic dysfunction was examined by applying two tests: blood pressure response to standing, and handgrip tests. Disease severity was assessed by the 28-joint-count disease activity score (DAS-28) and the disease activity score in psoriatic arthritis (DAPSA).

RESULTS

Cardiovascular reflex tests were impaired significantly among the PsA patients compared with well-matched healthy subjects (p < 0.05). Parasympathetic dysfunction was more prominent than sympathetic dysfunction. After 12 weeks treatment, parasympathetic dysfunction (heart rate response to deep breath and standing) significantly (p < 0.05) improved in patients with PsA, while there was no significant improvement in sympathetic function.

CONCLUSION

These study results suggests parasympathetic autonomic dysfunction is more prominent than sympathetic dysfunction in PsA. Synthetic DMARDs improved parasympathetic dysfunction in PsA.

Cardiovascular autonomic neuropathy in rheumatoid arthritis assessed by cardiovascular autonomic function tests: A cross-sectional survey

Objective:

In this study, we aimed to evaluate cardiovascular autonomic neuropathy (CAN) in RA patients by cardiovascular autonomic function tests. Because CAN was reported of patients with automimmune rheumatic diseases those may in sudden death or myocardial infarction.

Methods:

A total of 44 patients with RA and 44 age-and sex-matched healthy volunteers participated in this cross-sectional study. Assessment of CAN was performed using cardiovascular reflex tests. These five tests were: 1) beat-to-beat heart rate variation during deep breathing; 2) heart rate response to standing up; 3) heart rate response to the Valsalva maneuver; 4) blood pressure response to standing up; and 5) blood pressure response to sustained handgrip.

Results:

The mean age was 43.15 (SD, 12.18) years (range, 23-68 years) in the RA group, and 38 were women. In beat-to-beat heart rate variation during deep breathing, expiration-to-inspiration ratio was abnormal in 3 cases with RA (6.8%) but in 1 (2.3%) control subject (p=0.3), and maximum minus minimum heart rate was abnormal in 8 patients (18.2%) and in 3 (6.8%) control subjects (p=0.1). 2) In heart rate response to standing up, all patients and controls had normal results. Valsalva ratio was abnormal in 7 RA patients (15.9%) and in 7 control subjects (15.9%). Blood pressure response to standing up was normal in RA patients but abnormal in 1 (2.3%) control subject (p=0.4). Blood pressure response to sustained handgrip was abnormal in 5 RA patients (11.4%) and 2 (4.6%) control subjects (p=0.2).

Conclusion:

Our study failed to show any statistically significant difference between cardiovascular autonomic function tests in RA patients with control subjects by our test done.