Assessment of Gastrointestinal Autonomic Dysfunction: Present and Future Perspectives

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.

Neck triangle nerve enlargement in hereditary transthyretin amyloidosis correlates with changes in the autonomic, cardiac, and gastrointestinal systems

BACKGROUND

Hereditary transthyretin amyloidosis (ATTRv) is a hereditary disease that affects multiple bodily systems. Although sonography generally reveals enlargement of nerves in the limbs, the brachial plexus, and vagus nerve, the clinical significance of these findings remains unclear.

METHODS

We performed sonographic measurements of the median nerve, cervical spinal nerves at the C5-C7 level, and the vagus nerve in patients with ATTRv and healthy controls. Clinical profiles and cardiac and gastrointestinal examination results were also collected for linear regression analysis.

RESULTS

We recruited 47 patients with ATTRv (males/females: 34/13, age: 65.6 ± 5.3 years). The sampled segments were all significantly larger than those of the controls. In the clinical profiles, the sum of the Z scores of the neck triangle nerves (cervical spinal nerves and vagus nerve) and of all nerves (cervical spinal nerves, vagus nerve, and median nerve at the wrist) significantly correlated with the familial amyloid polyneuropathy stage, onset of autonomic nervous system (ANS) symptoms, and autonomic symptom scores. On cardiac examinations, several ultrasonography and magnetic resonance imaging parameters (primarily those that reflect heart volume) were found to be significantly correlated with the sum of the Z scores of the cervical spinal nerves but not with the Z score of the vagus nerve. In gastrointestinal evaluation, the cross-sectional area of the vagus nerve was correlated with gastric emptying time parameters on scintigraphy.

CONCLUSIONS

Neck triangle nerve enlargement on sonography correlated with parameters related to ANS dysfunction, indicating that nerve enlargement observed on ultrasonography may serve as a potential surrogate biomarker of ATTRv.

Evaluating the Associations Among Dysautonomia, Gastrointestinal Transit, and Clinical Phenotype in Patients With Systemic Sclerosis

OBJECTIVE

Our objective was to identify patients with systemic sclerosis (SSc) with a high burden of autonomic symptoms and to determine whether they have a distinct clinical phenotype, gastrointestinal (GI) transit, or extraintestinal features.

METHODS

In a prospective cohort of patients with SSc with GI disease, clinical data were systematically obtained at routine visits. Dysautonomia was identified by the Composite Autonomic Symptom Score (COMPASS)-31questionnaire. GI transit was measured by whole-gut scintigraphy. Associations between total COMPASS-31 scores and clinical features, GI symptoms, and transit were evaluated. Comparisons between patients with global autonomic dysfunction (GAD; ≥5 positive COMPASS-31 subdomains) and those with limited autonomic dysfunction (LAD; <5 positive subdomains) were also studied.

RESULTS

A total of 91 patients with SSc and GI involvement were included (mean age 57 years, 90% female, 74% limited cutaneous disease, 83% significant GI disease [Medsger score ≥2]). The mean COMPASS-31 score in patients with SSc was higher than controls (38.8 vs 7.2); 33% had GAD, and 67% had LAD. Patients with GAD were more likely to have limited SSc (93% vs 65%; P < 0.01) and have sicca symptoms (100% vs 77%; P = 0.01). Gastric and colonic transit were faster in patients with GAD (P < 0.05). Upper GI involvement (Medsger GI score of 1 or 2) was associated with higher total COMPASS-31 scores (P = 0.02).

CONCLUSION

Symptoms of global dysautonomia are seen in up to one-third of patients with SSc and GI involvement. Identifying specific clinical characteristics associated with GAD in SSc will help to identify a population that may benefit from therapies that modulate the autonomic nervous system.

Dopamine Receptors and TAAR1 Functional Interaction Patterns in the Duodenum Are Impaired in Gastrointestinal Disorders

Currently, there is a growing amount of evidence for the involvement of dopamine receptors and the functionally related trace amine-associated receptor, TAAR1, in upper intestinal function. In the present study, we analyzed their expression in the duodenum using publicly accessible transcriptomic data. We revealed the expression of DRD1, DRD2, DRD4, DRD5, and TAAR1 genes in different available datasets. The results of the gene ontology (GO) enrichment analysis for DRD2 and especially TAAR1 co-expressed genes were consistent with the previously described localization of D2 and TAAR1 in enteric neurons and secretory cells, respectively. Considering that co-expressed genes are more likely to be involved in the same biological processes, we analyzed genes that are co-expressed with TAAR1, DRD2, DRD4, and DRD5 genes in healthy mucosa and duodenal samples from patients with functional dyspepsia (FD) or diabetes-associated gastrointestinal symptoms. Both pathological conditions showed a deregulation of co-expression patterns, with a high discrepancy between DRDs and TAAR1 co-expressed gene sets in normal tissues and patients' samples and a loss of these genes' functional similarity. Meanwhile, we discovered specific changes in co-expression patterns that may suggest the involvement of TAAR1 and D5 receptors in pathologic or compensatory processes in FD or diabetes accordingly. Despite our findings suggesting the possible role of TAAR1 and dopamine receptors in functional diseases of the upper intestine, underlying mechanisms need experimental exploration and validation.

Enteric neuropathy in diabetes: Implications for gastrointestinal function

Diabetes, commonly known for its metabolic effects, also critically affects the enteric nervous system (ENS), which is essential in regulating gastrointestinal (GI) motility, secretion, and absorption. The development of diabetes-induced enteric neuropathy can lead to various GI dysfunctions, such as gastroparesis and irregular bowel habits, primarily due to disruptions in the function of neuronal and glial cells within the ENS, as well as oxidative stress and inflammation. This editorial explores the pathophysiological mechanisms underlying the development of enteric neuropathy in diabetic patients. Additionally, it discusses the latest advances in diagnostic approaches, emphasizing the need for early detection and intervention to mitigate GI complications in diabetic individuals. The editorial also reviews current and emerging therapeutic strategies, focusing on pharmacological treatments, dietary management, and potential neuromodulatory interventions. Ultimately, this editorial highlights the necessity of a multidisciplinary approach in managing enteric neuropathy in diabetes, aiming to enhance patient quality of life and address a frequently overlooked complication of this widespread disease.

Gastrointestinal symptom burden in diabetic autonomic and peripheral neuropathy - A Danes cohort study

OBJECTIVE

We investigated associations between gastrointestinal symptoms - evaluated as a combined weighted symptom score (CWSS) - Diabetic autonomic neuropathy (DAN), and distal symmetrical polyneuropathy (DSPN) in type 1 and type 2 diabetes.

RESEARCH DESIGN AND METHODS

Cross-sectional study in a tertiary outpatient clinic. CWSS was calculated based on questionnaires: gastroparesis composite symptom index (GCSI) and gastrointestinal symptom rating score (GSRS). DAN and DSPN were addressed using the composite autonomic symptom score 31 (COMPASS-31) questionnaire, cardiac autonomic reflex tests (CARTs), electrochemical skin conductance (ESC), vibration perception threshold (VPT), Michigan Neuropathy Screening Instrument (MNSI), pain- and thermal sensation. Analyses were adjusted for age, sex, diabetes duration, smoking, LDL-cholesterol, HbA1C and systolic blood pressure. Type 1 and type 2 diabetes were evaluated separately.

RESULTS

We included 566 with type 1 diabetes and 377 with type 2 diabetes. Mean ± SD age was 58 ± 15 years and 565 (59.9 %) were women. A high CWSS was present in 143 (25 %) with type 1 and 142 (38 %) with type 2 diabetes. The odds of DAN by COMPASS-31 (p < 0.001) were higher in the high score group. For type 1 diabetes, odds of cardiac autonomic neuropathy were higher in the high CWSS group. The odds of DSPN by VPT and MNSI in type 1 diabetes, and by ESC, VPT and pain sensation in type 2 diabetes were higher in the high CWSS group.

CONCLUSIONS

A high symptom score was associated with neuropathy by COMPASS-31 and vibration perception. Gastrointestinal symptom burden associated inconsistently with other neuropathy tests between diabetes types.

Exploring Electrical Neuromodulation as an Alternative Therapeutic Approach in Inflammatory Bowel Diseases

Background and Objectives: This review systematically evaluates the potential of electrical neuromodulation techniques-vagus nerve stimulation (VNS), sacral nerve stimulation (SNS), and tibial nerve stimulation (TNS)-as alternative treatments for inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's Disease (CD). It aims to synthesize current evidence on the efficacy and safety of these modalities, addressing the significant burden of IBD on patient quality of life and the limitations of existing pharmacological therapies. Materials and Methods: We conducted a comprehensive analysis of studies from PubMed, focusing on research published between 1978 and 2024. The review included animal models and clinical trials investigating the mechanisms, effectiveness, and safety of VNS, SNS, and TNS in IBD management. Special attention was given to the modulation of inflammatory responses and its impact on gastrointestinal motility and functional gastrointestinal disorders associated with IBD. Results: Preliminary findings suggest that VNS, SNS, and TNS can significantly reduce inflammatory markers and improve symptoms in IBD patients. These techniques also show potential in treating related gastrointestinal disorders during IBD remission phases. However, the specific mechanisms underlying these benefits remain to be fully elucidated, and there is considerable variability in treatment parameters. Conclusions: Electrical neuromodulation holds promise as a novel therapeutic avenue for IBD, offering an alternative to patients who do not respond to traditional treatments or experience adverse effects. The review highlights the need for further rigorous studies to optimize stimulation parameters, understand long-term outcomes, and integrate neuromodulation effectively into IBD treatment protocols.

Effectiveness of Novel Sympathetic Nerve Entrapment Point Injections for Chronic Migraine: A Pilot Study

No studies to date have investigated the ability of sympathetic nerve entrapment point saline (SNEP) injections to achieve long-term pain relief in patients with migraine. Therefore, this study aimed to investigate the safety and long-term efficacy of repeat splenius capitis (SC) SNEP injections in patients with migraine (with/without tension-type headache). This retrospective, single-arm study included 12 patients with migraine. Isotonic saline was injected into their SC approximately six times for 3 months. Headache frequency, duration (hour/week), intensity (using the visual analog scale), and quality of life (using the Headache Impact Test-6) were assessed during the follow-up visits for up to 24 months after the first injection. Changes before and after treatment were assessed using repeated-measures analysis of variance. Significant reductions in headache frequency, duration, and intensity were observed at all assessment points after SNEP injections when compared with the baseline values (p < 0.05), while the patients' headache-related quality of life also improved. Treatment was continued for up to 3 months to maintain these improvements, and no worsening of status or adverse effects were observed in any of the patients over the following 24 months. Our results show that SNEP injections may offer persistent, substantial, and clinically relevant benefits in patients with migraine.

Pathways to Anxiety and Depression in Autistic Adolescents and Adults

Individuals diagnosed with autism spectrum disorder (autism) commonly experience co-occurring anxiety and depression, which are significantly associated. These mental health conditions are also variously associated with increased autistic traits, insomnia, intolerance of uncertainty (IU), sensory sensitivity, and autonomic symptoms. However, no research has explored the relationships between IU, sensory sensitivity, autonomic symptoms, insomnia, and autistic traits and how they might be associated with anxiety and depression in autism. This study took a transdiagnostic approach to explore the relationships between anxiety, depression, autistic traits, insomnia, IU, sensory sensitivities, and autonomic arousal in 222 autistic people aged 15-80 years (55.7% female) using path analysis. Four plausible, theoretical models were tested, with model 1 providing best fit and explaining 48% of variance in depression, 37% of variance in anxiety, and 29% of variance in insomnia. Autistic traits and IU were directly associated with anxiety and indirectly associated with depression through anxiety. Anxiety, insomnia, IU, and sensory sensitivity were all directly associated with depression; autonomic arousal and sensory sensitivity were also indirectly associated with depression through insomnia. Thus, multiple pathways can lead to anxiety and depression in autism, not only via known paths such as insomnia and IU but additionally via autonomic arousal and sensory sensitivities which are also elevated in autism. These findings suggest that careful clinical evaluation and individualised treatment plans are needed for autistic adults with anxiety or depression. When considering prevention, programs that help autistic adults reduce arousal, maintain good sleep, and reduce IU may prove fruitful.

Patterns of Food Selectivity among Children with Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a heterogeneous group of neurodevelopmental disorders characterized by food selectivity in a significant portion of the population. The nature of this selectivity remains unclear, with hypotheses suggesting associations with sensory disorders or stereotypical and repetitive patterns of activity and interests. This study aimed to determine the prevalence and nature of food selectivity traits in individuals with ASD compared with the neurotypical population. This study involved 219 participants, with 115 diagnosed with autism and 92 without. Twelve children undergoing diagnosis were excluded from the analyses. The findings revealed that food selectivity traits are more common in individuals with ASD, with differences in preferences mainly involving structure, color, taste, and serving method. Children with ASD had more food selectivity traits than those without, and the intake of certain food characteristics could be altered as they grow. Selectivity occurred for both sensory and stereotypical reasons, but stereotypical features significantly differentiated neurotypical individuals from those with ASD.

COVID-19-induced gastrointestinal autonomic dysfunction: A systematic review

In recent years, because of the growing desire to improve the noninvasiveness and safety of tumor treatments, sonodynamic therapy has gradually become a popular research topic. However, due to the complexity of the therapeutic process, the relevant mechanisms have not yet been fully elucidated. One of the widely accepted possibilities involves the effect of reactive oxygen species. In this review, the mechanism of reactive oxygen species production by sonodynamic therapy (SDT) and ways to enhance the sonodynamic production of reactive oxygen species are reviewed. Then, the clinical application and limitations of SDT are discussed. In conclusion, current research on sonodynamic therapy should focus on the development of sonosensitizers that efficiently produce active oxygen, exhibit biological safety, and promote the clinical transformation of sonodynamic therapy.

COVID-19-induced gastrointestinal autonomic dysfunction: A systematic review

BACKGROUND

It is common for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection to occur in the gastrointestinal tract, which can present itself as an initial symptom. The severity of coronavirus disease 2019 (COVID-19) is often reflected in the prevalence of gastrointestinal symptoms. COVID-19 can damage the nerve supply to the digestive system, leading to gastrointestinal autonomic dysfunction. There is still much to learn about how COVID-19 affects the autonomic nervous system and the gastrointestinal tract.

AIM

To thoroughly explore the epidemiology and clinical aspects of COVID-19-induced gastrointestinal autonomic dysfunction, including its manifestations, potential mechanisms, diagnosis, differential diagnosis, impact on quality of life, prognosis, and management and prevention strategies.

METHODS

We conducted a thorough systematic search across various databases and performed an extensive literature review. Our review encompassed 113 studies published in English from January 2000 to April 18, 2023.

RESULTS

According to most of the literature, gastrointestinal autonomic dysfunction can seriously affect a patient's quality of life and ultimate prognosis. Numerous factors can influence gastrointestinal autonomic nervous functions. Studies have shown that SARS-CoV-2 has a well-documented affinity for both neural and gastrointestinal tissues, and the virus can produce various gastrointestinal symptoms by reaching neural tissues through different pathways. These symptoms include anorexia, dysgeusia, heartburn, belching, chest pain, regurgitation, vomiting, epigastric burn, diarrhea, abdominal pain, bloating, irregular bowel movements, and constipation. Diarrhea is the most prevalent symptom, followed by anorexia, nausea, vomiting, and abdominal pain. Although COVID-19 vaccination may rarely induce autonomic dysfunction and gastrointestinal symptoms, COVID-19-induced autonomic effects significantly impact the patient's condition, general health, prognosis, and quality of life. Early diagnosis and proper recognition are crucial for improving outcomes. It is important to consider the differential diagnosis, as these symptoms may be induced by diseases other than COVID-19-induced autonomic dysfunction. Treating this dysfunction can be a challenging task.

CONCLUSION

To ensure the best possible outcomes for COVID-19 patients, it is essential to take a multidisciplinary approach involving providing supportive care, treating the underlying infection, managing dysfunction, monitoring for complications, and offering nutritional support. Close monitoring of the patient's condition is crucial, and prompt intervention should be taken if necessary. Furthermore, conducting thorough research on the gastrointestinal autonomic dysfunction caused by COVID-19 is vital to manage it effectively.

Reduction of Pain After Laparoscopic Bariatric Surgery by Personalized Checkpoint Acupuncture-Data of a STRICTA Conform Pilot Study

BACKGROUND

It remains challenging in clinical practice to perform optimal pain management following bariatric surgeries. Acupuncture (AC) is an effective method of postoperative pain management, but its clinical efficacy depends on the rationale used to select AC points.

METHODS

We developed a method to identify individual patterns of pain and a corresponding set of acupoints (corrAC) based on the relative pressure sensitivity of six abdominal visceral pressure points, i.e., the gastrointestinal (GI) checkpoints (G1-G6). Patients with moderate to severe pain were included and received a single AC treatment following surgery. The visual analog scale (VAS) score, pain threshold, and skin temperature were assessed before AC and at 5 min, 1 h, and 24 h following AC. AC was performed with 1-mm-deep permanent needles.

RESULTS

From April 2021 to March 2022, 72 patients were included in the analysis. Fifty-nine patients received corrAC, whereas 13 received a noncorresponding AC (nonAC) as an internal control. Patients receiving corrAC showed a significant reduction (74%) in pain at 5 min after treatment (p < 0.0001) and a significant increase (37%) in the pain threshold (p < 0.0001). In this group, a significant increase in skin temperature above G1, G3, G4, and G5 was observed. Patients receiving nonAC showed neither significant pain reduction nor significant changes in pain threshold. The skin above G3 and G4 did not reveal temperature changes.

CONCLUSION

Checkpoint AC may be an effective tool in postoperative pain therapy after bariatric surgery. Vegetative functional involvement might be associated with pain relief.

SmartPill™ Administration to Assess Gastrointestinal Function after Spinal Cord Injury in a Porcine Model-A Preliminary Study

Gastrointestinal (GI) complications, including motility disorders, metabolic deficiencies, and changes in gut microbiota following spinal cord injury (SCI), are associated with poor outcomes. After SCI, the autonomic nervous system becomes unbalanced below the level of injury and can lead to severe GI dysfunction. The SmartPill™ is a non-invasive capsule that, when ingested, transmits pH, temperature, and pressure readings that can be used to assess effects in GI function post-injury. Our minipig model allows us to assess these post-injury changes to optimize interventions and ultimately improve GI function. The aim of this study was to compare pre-injury to post-injury transit times, pH, and pressures in sections of GI tract by utilizing the SmartPill™ in three pigs after SCI at 2 and 6 weeks. Tributyrin was administered to two pigs to assess the influences on their gut microenvironment. We observed prolonged GET (Gastric Emptying Time) and CTT (Colon Transit Time), decreases in contraction frequencies (Con freq) in the antrum of the stomach, colon, and decreases in duodenal pressures post-injury. We noted increases in Sum amp generated at 2 weeks post-injury in the colon, with corresponding decreases in Con freq. We found transient changes in pH in the colon and small intestine at 2 weeks post-injury, with minimal effect on stomach pH post-injury. Prolonged GETs and CTTs can influence the absorptive profile in the gut and contribute to pathology development. This is the first pilot study to administer the SmartPill™ in minipigs in the context of SCI. Further investigations will elucidate these trends and characterize post-SCI GI function.

Early Gastrointestinal Neuropathy Assessed by Wireless Motility Capsules in Adolescents with Type 1 Diabetes

BACKGROUND

To assess the prevalence of objective signs of gastrointestinal (GI) autonomic neuropathy (AN) in adolescents with type 1 diabetes (T1D). In addition, to investigate associations between objective GI findings and self-reported symptoms or other findings of AN.

METHODS

Fifty adolescents with T1D and 20 healthy adolescents were examined with a wireless motility capsule to assess the total and regional GI transit times and motility index. GI symptoms were evaluated with the GI Symptom Rating Scale questionnaire. AN was evaluated with cardiovascular and quantitative sudomotor axon reflex tests.

RESULTS

There was no difference in GI transit times in adolescents with T1D and healthy controls. Adolescents with T1D had a higher colonic motility index and peak pressure than the controls, and GI symptoms were associated with low gastric and colonic motility index (all p < 0.05). Abnormal gastric motility was associated with the duration of T1D, while a low colonic motility index was inversely associated with "time in target range" for blood glucose (all p < 0.01). No associations were found between signs of GI neuropathy and other measures of AN.

CONCLUSIONS

Objective signs of GI neuropathy are common in adolescents with T1D and it seems to require early interventions in patients at high risk of developing GI neuropathy.

Pathophysiology, Functional Assessment and Prognostic Implications of Nutritional Disorders in Systemic Amyloidosis

Gastrointestinal involvement is a common clinical feature of patients with systemic amyloidosis. This condition is responsible for invalidating gastrointestinal symptoms, a significant macro and micronutrient deficit, and is a marker of disease severity. Gastrointestinal involvement should be actively sought in patients with systemic amyloidosis, while its diagnosis is challenging in patients with isolated gastrointestinal symptoms. The nutritional status in systemic amyloidosis plays an essential role in the clinical course and is considered a significant prognostic factor. However, the definition of nutritional status is still challenging due to the lack of internationally accepted thresholds for anthropometric and biochemical variables, especially in specific populations such as those with systemic amyloidosis. This review aims to elucidate the fundamental steps for nutritional assessment by using clinical and instrumental tools for better prognostic stratification and patient management regarding quality of life and outcomes.

Quantitative gastrointestinal function and corresponding symptom profiles in autonomic neuropathy

Purpose

Peripheral neuropathies with autonomic nervous system involvement are a recognized cause of gastrointestinal dysmotility for a wide spectrum of diseases. Recent advances in wireless motility capsule testing allow improved sampling of regional and whole gut motility to aid in the diagnosis of gastrointestinal motility disorders and may provide additional insight into segment-specific enteric involvement of peripheral neuropathies affecting autonomic nervous system function.

Methods

We utilized standardized autonomic nervous system (ANS) reflex assessment and wireless motility capsule testing to evaluate 20 individuals with idiopathic autonomic neuropathy and unexplained gastrointestinal symptoms. Additionally, we examined the relationship between quantifiable autonomic neuropathy and gastrointestinal dysmotility at specific neuroanatomical levels. Symptom profiles were evaluated using the 31-item Composite Autonomic Symptom Score questionnaire (COMPASS-31) and compared to wireless motility capsule data.

Results

We found that transit times were predominately abnormal (delayed) in the foregut (10 of 20; 50%), while contractility abnormalities were far more prominent in the hindgut (17 of 20; 85%), and that motility and symptom patterns, as assessed by the COMPASS-31 GI domain items, generally corresponded. Finally, we also found that there was neuroanatomical overlap in the presence of autonomic reflex abnormalities and WMC-based transit and/or contractility abnormalities.

Conclusions

We found that transit times were predominately abnormal in the foregut and midgut, while contractility abnormalities were far more prominent in the hindgut in individuals with idiopathic autonomic neuropathy. There was a high rate of agreement in segmental wireless motility capsule data with neuroanatomically corresponding standardized ANS function measures (e.g., cardiovagal, sudomotor, adrenergic). Expanded sudomotor testing, including additional neuroanatomical segments, could provide additional indirect assessment of visceral involvement in ANS dysfunction.