Sympathetic Neuronal Activation Triggers Myeloid Progenitor Proliferation and Differentiation.

There is a growing body of research on the neural control of immunity and inflammation. However, it is not known whether the nervous system can regulate the production of inflammatory myeloid cells from hematopoietic progenitor cells in disease conditions. Myeloid cell numbers in diabetic patients were strongly correlated with plasma concentrations of norepinephrine, suggesting the role of sympathetic neuronal activation in myeloid cell production. The spleens of diabetic patients and mice contained higher numbers of tyrosine hydroxylase (TH)-expressing leukocytes that produced catecholamines. Granulocyte macrophage progenitors (GMPs) expressed the ß2 adrenergic receptor, a target of catecholamines. Ablation of splenic sympathetic neuronal signaling using surgical, chemical, and genetic approaches diminished GMP proliferation and myeloid cell development. Finally, mice lacking TH-producing leukocytes had reduced GMP proliferation, resulting in diminished myelopoiesis. Taken together, our study demonstrates that catecholamines produced by leukocytes and sympathetic nerve termini promote GMP proliferation and myeloid cell development.

AGA Clinical Practice Update on Diagnosis and Management of Cyclic Vomiting Syndrome: Commentary.

DESCRIPTION: The purpose of this American Gastroenterological Association (AGA) Institute Clinical Practice Update (CPU) is to review the available evidence and provide expert advice regarding the diagnosis and management of cyclic vomiting syndrome. METHODS: This CPU was commissioned and approved by the AGA Institute Clinical Practice Updates Committee (CPUC) and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the CPUC and external peer review through standard procedures of Gastroenterology. This expert commentary incorporates important as well as recently published studies in this field, and it reflects the experiences of the authors who are experts in treating patients with cyclic vomiting syndrome.

Epidemiology, Comorbidities, and Treatment of Cyclic Vomiting Syndrome in the United States.

INTRODUCTION: Cyclic vomiting syndrome (CVS) imposes a substantial burden, but epidemiological data are scarce. This study aimed to estimate the incidence and prevalence of CVS, comorbid conditions, and treatment patterns, using administrative databases in the United States. METHODS: This cross-sectional study used claims data from Merative MarketScan Commercial/Medicare Supplemental and Medicaid databases in all health care settings. Incidence and prevalence rates for 2019 were calculated and stratified by age, sex, region, and race/ethnicity. Patient characteristics were reported among newly diagnosed patients with CVS (i.e., no documented claims for CVS before 2019). CVS was defined as having 1+ inpatient and/or 2+ outpatient CVS claims that were 7+ days apart. RESULTS: The estimated prevalence of CVS was 16.7 (Commercial/Medicare) and 42.9 (Medicaid) per 100,000 individuals. The incidence of CVS was estimated to be 10.6 (Commercial/Medicare) and 26.6 (Medicaid) per 100,000 individuals. Both prevalence and incidence rates were higher among female individuals (for both Commercial/Medicare and Medicaid). Comorbid conditions were common and included abdominal pain (56%-64%), anxiety (32%-39%), depression (26%-34%), cardiac conditions (39%-42%), and gastroesophageal reflux disease (30%-40%). Despite a diagnosis of CVS, only 32%-35% had prescriptions for prophylactic treatment and 47%-55% for acute treatment within the first 30-day period following diagnosis. DISCUSSION: This study provides the first population-level estimates of CVS incidence and prevalence in the United States. Comorbid conditions are common, and most patients with CVS do not receive adequate treatment. These findings underscore the need for improving disease awareness and developing better screening strategies and effective treatments.

Nightshade Vegetables: A Dietary Trigger for Worsening Inflammatory Bowel Disease and Irritable Bowel Syndrome?

The Solanaceae family of plants, commonly known as Nightshade vegetables or Nightshades, contains a diverse range of crops of over 2000 members with significant culinary, economic, and cultural importance. Familiar edible Nightshades include tomatoes, peppers, eggplants, and white potatoes. Many pharmacologically active compounds used in traditional medicine, including atropine and hyoscyamine, are derived from Nightshades. In addition to these beneficial pharmacologic agents, Nightshade-derived glycoalkaloid compounds, a key defense mechanism against predation, have been shown to disrupt intestinal epithelium and to potentially activate mast cells in the gut mucosa, leading to adverse symptoms in humans. There is a new appreciation that mast cell activation is an allergic inflammatory mechanism contributing both to pain in irritable bowel syndrome (IBS) and to gut inflammation in inflammatory bowel disease (IBD). Given their ubiquity in Western diets and their shared glycoalkaloid active compounds, edible Nightshades are attracting new interest as a potential trigger for worsening gut symptoms in functional and inflammatory gastrointestinal disorders. Here, we review the limited existing literature on the adverse effects of Nightshade consumption, including the effects of Nightshade-derived glycoalkaloids on IBD gut inflammation, and the under-recognized contribution of Nightshades to food allergies and allergic cross-reactivity. We then highlight new evidence on the contributions of mast cell activation to GI disorder pathogenesis, including potential linkages between Nightshade antigens, intestinal mast cells, and GI dysfunction in IBS and IBD.

Multiple areas of the cerebral cortex influence the stomach.

The central nervous system both influences and is influenced by the gastrointestinal system. Most research on this gut-brain connection has focused on how ascending signals from the gut and its microbiome alter brain function. Less attention has focused on how descending signals from the central nervous system alter gut function. Here, we used retrograde transneuronal transport of rabies virus to identify the cortical areas that most directly influence parasympathetic and sympathetic control of the rat stomach. Cortical neurons that influence parasympathetic output to the stomach originated from the rostral insula and portions of medial prefrontal cortex, regions that are associated with interoception and emotional control. In contrast, cortical neurons that influence sympathetic output to the stomach originated overwhelmingly from the primary motor cortex, primary somatosensory cortex, and secondary motor cortex, regions that are linked to skeletomotor control and action. Clearly, the two limbs of autonomic control over the stomach are influenced by distinct cortical networks.

Development and Assessment of a Low Literacy, Pictographic Cyclic Vomiting Syndrome Action Plan.

OBJECTIVE: To develop and assess an evidence-based, individualized Cyclic Vomiting Syndrome Action Plan (CVSAP) to optimize both preventative and acute care. STUDY DESIGN: This implementation science project synthesized a combination of clinical practice guidelines, published literature, and clinical experience by a team of CVS clinicians to develop the CVSAP. The tool was developed to include validated pictograms and an automatic, embedded, weight-based dosing calculator to output acute management recommendations. The final version of the CVSAP was tested by patients/caregivers, readability calculators, medical librarians, and clinicians using validated metrics. RESULTS: All pictograms met the criteria for inclusion in the CVSAP. A composite readability score of 5.32 was consistent with a fifth-grade level. Patients/caregivers (n = 70) judged the CVSAP to be of high quality with consumer information rating form rating of 84.2%. Six medical librarians rated the CVSAP to have 93% understandability and 100% actionability, and 33 clinicians completing the SAM generated a suitability rating of 87.5%. CONCLUSIONS: The CVSAP visually highlights individualized care plan components to facilitate optimized preventative and acute CVS care. Further investigation will determine if CVSAP increases caregiver confidence and compliance in home management and improves quality of life and clinical outcomes for patients with CVS.

The mind-body problem: Circuits that link the cerebral cortex to the adrenal medulla.

Which regions of the cerebral cortex are the origin of descending commands that influence internal organs? We used transneuronal transport of rabies virus in monkeys and rats to identify regions of cerebral cortex that have multisynaptic connections with a major sympathetic effector, the adrenal medulla. In rats, we also examined multisynaptic connections with the kidney. In monkeys, the cortical influence over the adrenal medulla originates from 3 distinct networks that are involved in movement, cognition, and affect. Each of these networks has a human equivalent. The largest influence originates from a motor network that includes all 7 motor areas in the frontal lobe. These motor areas are involved in all aspects of skeletomotor control, from response selection to motor preparation and movement execution. The motor areas provide a link between body movement and the modulation of stress. The cognitive and affective networks are located in regions of cingulate cortex. They provide a link between how we think and feel and the function of the adrenal medulla. Together, the 3 networks can mediate the effects of stress and depression on organ function and provide a concrete neural substrate for some psychosomatic illnesses. In rats, cortical influences over the adrenal medulla and the kidney originate mainly from 2 motor areas and adjacent somatosensory cortex. The cognitive and affective networks, present in monkeys, are largely absent in rats. Thus, nonhuman primate research is essential to understand the neural substrate that links cognition and affect to the function of internal organs.

Motor, cognitive, and affective areas of the cerebral cortex influence the adrenal medulla.

Modern medicine has generally viewed the concept of "psychosomatic" disease with suspicion. This view arose partly because no neural networks were known for the mind, conceptually associated with the cerebral cortex, to influence autonomic and endocrine systems that control internal organs. Here, we used transneuronal transport of rabies virus to identify the areas of the primate cerebral cortex that communicate through multisynaptic connections with a major sympathetic effector, the adrenal medulla. We demonstrate that two broad networks in the cerebral cortex have access to the adrenal medulla. The larger network includes all of the cortical motor areas in the frontal lobe and portions of somatosensory cortex. A major component of this network originates from the supplementary motor area and the cingulate motor areas on the medial wall of the hemisphere. These cortical areas are involved in all aspects of skeletomotor control from response selection to motor preparation and movement execution. The second, smaller network originates in regions of medial prefrontal cortex, including a major contribution from pregenual and subgenual regions of anterior cingulate cortex. These cortical areas are involved in higher-order aspects of cognition and affect. These results indicate that specific multisynaptic circuits exist to link movement, cognition, and affect to the function of the adrenal medulla. This circuitry may mediate the effects of internal states like chronic stress and depression on organ function and, thus, provide a concrete neural substrate for some psychosomatic illness.

Prevalence of Nausea and Vomiting in Adults Using Ropinirole: A Systematic Review and Meta-Analysis.

BACKGROUND: Nausea and vomiting are commonly associated with medication use. Dopaminergic agonists have been associated with these symptoms, but their impact in patients without Parkinson's disease, such as those with restless legs syndrome (RLS), is not well characterized. AIMS: We sought to determine whether the non-ergoline dopamine agonist ropinirole is associated with nausea and vomiting in adults with RLS. METHODS: We conducted a systematic review using PUBMED, EMBASE, and clinical trial databases to identify placebo-controlled clinical trials of ropinirole for RLS treatment. We extracted data including dosing schedule and the proportion of patients reporting nausea and/or vomiting. We also determined hazard ratios (HR) using a random effects proportional hazard model. RESULTS: We extracted data from a pool of 13 studies. The prevalence of nausea in the ropinirole-treated RLS group (RLS-R; N = 1528) was 37.2% compared to 9.4% in the placebo-treated RLS group (RLS-P; N = 1395) (p < 0.0001). The prevalence of vomiting in the RLS-R group was 10.9% compared to 2.6% in the RLS-P group (p < 0.0001). Ropinirole use was associated with a higher risk of reporting nausea (HR 5.924 [4.410-7.959], p < 0.001) and experiencing vomiting (HR 4.628 [3.035-7.057], p < 0.0001). Nausea and vomiting represented nearly 50% of all adverse events reported. CONCLUSIONS: Nausea and vomiting are quite common side effects in those using ropinirole for RLS. As RLS is more widely recognized and treated; the prevalence of ropinirole-induced nausea and vomiting could grow substantially. Ropinirole use should be considered as a cause of chronic nausea and vomiting.

Acute care of cyclic vomiting syndrome and cannabinoid hyperemesis syndrome in the home and emergency department for: Special supplement/proceedings of 3rd international symposium.

BACKGROUND: Cyclic vomiting syndrome (CVS) and cannabinoid hyperemesis syndrome (CHS) are both characterized by episodic, acute transitions from asymptomatic states to highly symptomatic states of nausea, repetitive vomiting, and often severe abdominal pain. Patients with CVS and CHS face significant challenges to abort or mitigate episodes at home and often require emergency department (ED)-based care. PURPOSE: This paper reviews the current treatment approach to abort acute CVS and CHS episodes at home and in ED settings. Multiple pharmacologic and nonpharmacologic interventions have been demonstrated to potentially abort CVS or CHS episodes. Systemic pharmacologic agents often used as abortive therapy include triptans, antiemetics, anxiolytics, NK-1 receptor antagonists, antipsychotics, sedatives in general, and various analgesic / anti-inflammatory medications. Nonsystemic, nonpharmacologic approaches include reducing external stimuli (quiet room, dim lights, etc.), and hot water bathing or the application of topical capsaicin cream. More research is needed to develop evidence-based, individualized abortive treatment plans, as well as to determine whether the abortive treatment for CVS requires a fundamentally different approach than for CHS. When home-based approaches fail, all patients with CVS or CHS should receive nonjudgmental, informed, and compassionate care in the ED to abort their episode. Patients with more severe forms of CVS/CHS who require more frequent ED utilization should develop care plans with their ED to assure predictable and effective treatment.

Cyclic vomiting syndrome: Future clinical and research priorities for: Special supplement/proceedings of 3rd international symposium.

BACKGROUND: An increasing number of studies have explored the clinical features, epidemiology, pathophysiology, and management of cyclic vomiting syndrome (CVS). CVS is common in adults and children and negatively impacts patients, families, and the healthcare system. A related condition, cannabinoid hyperemesis syndrome (CHS), has been a focus of interest in the lay press and published literature. PURPOSE: Clinical presentations of CVS have been defined by small series and expert opinion, but recent prospective studies are refining our understanding of the spectrum of emetic episodes and the breadth of comorbid conditions. Large cross-sectional population analyses are clarifying CVS prevalence and factors related to age, ethnicity, and geographic region. CVS pathophysiology is multifactorial with contributions from migraines, dysautonomia, endogenous cannabinoids, mitochondrial dysfunction, genetic abnormalities, and rapid gastric emptying. CVS treatment relies on antiemetics and antimigraine therapies to abort acute episodes coupled with prophylactic regimens employing neuromodulators and antiepileptics. CHS represents a challenge partly because of difficulties in achieving sustained cannabis abstinence. Benefits of other therapies in CHS remain poorly defined. Several areas warrant further scrutiny including better identification of CVS triggers and characterization of different CVS subsets including those with frequent severe episodes, refined description of epidemiology to allow targeting of populations predisposed to CVS development, rigorous definition of pathogenic factors to provide a foundation for exploratory studies of novel therapies, and conduct of controlled trials by multicenter collaborations to confirm benefits of existing and new therapies in development. Progress in these areas will be facilitated by generous governmental and industry support.

Suboptimal Performance of Microscopic Colitis Diagnosis Codes: A Bottleneck for Epidemiologic Insights.

INTRODUCTION: Administrative health data could contribute to generalizable microscopic colitis insights, but International Classification of Diseases (ICD) codes for microscopic colitis have not been validated. METHODS: We identified individuals who received care for diarrhea in the Veterans Health Administration and classified them by receipt of microscopic colitis ICD codes. We reviewed random samples of charts to calculate the positive predictive value (PPV) and negative predictive value (NPV). We then calculated the sensitivity and specificity in clinically relevant cohorts. RESULTS: The PPV was 0.790 and the NPV was 0.995. In a cohort of individuals with diarrhea who underwent colonoscopy, the sensitivity and specificity were 0.734 and 0.996, respectively. CONCLUSION: Alternative ascertainment methods for microscopic colitis are needed because ICD codes have suboptimal performance.

The motor cortex communicates with the kidney.

We used retrograde transneuronal transport of rabies virus from the rat kidney to identify the areas of the cerebral cortex that are potential sources of central commands for the neural regulation of this organ. Our results indicate that multiple motor and nonmotor areas of the cerebral cortex contain output neurons that indirectly influence kidney function. These cortical areas include the primary motor cortex (M1), the rostromedial motor area (M2), the primary somatosensory cortex, the insula and other regions surrounding the rhinal fissure, and the medial prefrontal cortex. The vast majority of the output neurons from the cerebral cortex were located in two cortical areas, M1 (68%) and M2 (15%). If the visceromotor functions of M1 and M2 reflect their skeletomotor functions, then the output to the kidney from each cortical area could make a unique contribution to autonomic control. The output from M1 could add precision and organ-specific regulation to descending visceromotor commands, whereas the output from M2 could add anticipatory processing which is essential for allostatic regulation. We also found that the output from M1 and M2 to the kidney originates predominantly from the trunk representations of these two cortical areas. Thus, a map of visceromotor representation appears to be embedded within the classic somatotopic map of skeletomotor representation.

Understanding Our Tests: Hydrogen-Methane Breath Testing to Diagnose Small Intestinal Bacterial Overgrowth.

There is increasing appreciation that small intestinal bacterial overgrowth (SIBO) drives many common gastrointestinal symptoms, including diarrhea, bloating, and abdominal pain. Breath testing via measurement of exhaled hydrogen and methane gases following ingestion of a readily metabolized carbohydrate has become an important noninvasive testing paradigm to help diagnose SIBO. However, because of a number of physiological and technical considerations, how and when to use breath testing in the diagnosis of SIBO remains a nuanced clinical decision. This narrative review provides a comprehensive overview of breath testing paradigms including the indications for testing, how to administer the test, and how patient factors influence breath testing results. We also explore the performance characteristics of breath testing (sensitivity, specificity, positive and negative predictive values, likelihood ratios, and diagnostic odds ratio). Additionally, we describe complementary and alternative tests for diagnosing SIBO. We discuss applications of breath testing for research. Current estimates of SIBO prevalence among commonly encountered high-risk populations are reviewed to provide pretest probability estimates under a variety of clinical situations. Finally, we discuss how to integrate breath test performance characteristics into clinical care decisions using clinical predictors and the Fagan nomogram.

Health Care Resource Use and Associated Costs of Cyclic Vomiting Syndrome in the United States.

BACKGROUND AND AIMS: This study aimed to estimate the extent of US health care resource use (HRU) and direct cost burden of cyclic vomiting syndrome (CVS). Methods: We selected patients in the MarketScan Commercial and Medicare Supplemental databases with ≥1 inpatient (IP) or ≥2 outpatient (OP) claims for CVS between October 1, 2015 and June 30, 2019, and continuous insurance enrollment for ≥12 months before (baseline) and ≥3 months after first CVS diagnosis (index). Using propensity scores based on baseline characteristics, each patient with CVS was matched to ∼3 non-CVS controls. We annualized HRU and costs to accommodate varying follow-up periods. Multivariable regressions further balanced CVS and non-CVS groups, and differences in HRU and costs between the matched cohorts were compared to quantify the direct cost burden of CVS. Results: Patients with CVS incurred significantly higher average annualized HRU, with the largest differences in emergency room (1.9 vs 0.4) visits and hospital IP (0.9 vs 0.1) stays (P < .001). Patients with CVS had significantly higher annual total health care costs ($57,140 vs $14,912), with IP spending as the primary driver ($28,522 vs $3250) of the cost difference (all P < .001). After multivariable regression adjustments, total health care costs remained 4.1 times higher for patients with CVS relative to non-CVS controls, with IP costs 12.3 times higher, emergency room costs 5.8 times higher, OP visit costs 2.9 times higher, and OP pharmacy costs 1.5 times higher (all P < .001). Conclusion: Newly diagnosed patients with CVS have greater health care utilization and higher costs than matched non-CVS counterparts, suggesting substantial economic burden of CVS on the US health care system.

Productivity Loss and Indirect Burden of Cyclic Vomiting Syndrome in the United States.

Background and Aims: To quantify the indirect burden of cyclic vomiting syndrome (CVS), we assessed work-related productivity loss in patients with CVS and caregivers using large-sized databases in the United States. Methods: Patients aged 18-64 years with full-time employment in MarketScan Commercial and Health and Productivity Management Databases were selected if they had ≥1 inpatient or ≥2 outpatient claims for CVS between 2008 and 2018 and continuous enrollment of ≥6 months before and ≥3 months after the initial CVS diagnosis. CVS caregivers were adults with full-time employment and also having dependent(s) with CVS. Propensity scores via multivariable regressions were used to match patients with CVS and their caregivers to non-CVS controls. Productivity loss was assessed by short-term disability (STD) and absenteeism (ABS) days, and the associated costs were also calculated. Differences between the matched cohorts were regarded as the burden attributable to CVS. Results: Patients with CVS had longer annualized STD (21.1 vs 7.0, P < .001) and ABS days (26.4 vs 22.8, P < .05) than their matched controls. CVS caregivers had more annualized STD (3.9 vs 2.6, P < .001) and ABS days (20.9 vs 19.5, P < .05) than controls. Productivity loss costs for STD or ABS days were greater for patients with CVS and caregivers. Annualized health-care resource utilization (inpatient, emergency room, outpatient) was 5.2-6.0 times higher in patients with CVS (P < .001). Conclusion: CVS is associated with higher productivity loss due to STD/ABS and, therefore, greater indirect costs for patients and caregivers. Further research is needed to assess the full societal burden of CVS. More effective interventions may reduce the disease burden.

Improvement of Cyclic Vomiting Syndrome with Outpatient Ketamine Infusions.

Cyclic vomiting syndrome (CVS) is a disorder characterized by recurrent flares of nausea and vomiting, often with significant abdominal pain, of several days duration. Although traditional prophylactic and abortive treatments for CVS are often successful, a subset of CVS patients with chronic abdominal pain may not respond as well to standard therapies. This report is the first, to our knowledge, to describe the use of outpatient ketamine infusions as therapy for refractory CVS. We describe a 63-year-old woman with history of CVS who presented with abdominal pain and recurrent episodes of nausea and vomiting. She first received ketamine during an inpatient admission for a CVS flare, with the aim of treating the abdominal pain. Given her improvement, she was offered a series of outpatient ketamine infusions, which led to a significant reduction in her symptoms. Thus, ketamine may be useful as both an abortive and prophylactic therapy in CVS. Prior reports have noted the anti-emetic effects of ketamine in the perioperative setting, and there is emerging evidence for the use of ketamine infusions for the treatment of chronic pain. However, this report is the first to describe ketamine as a potential prophylactic treatment for CVS.

Greater intolerance to uncertainty predicts poorer quality of life in adults with cyclic vomiting syndrome.

BACKGROUND: Cyclic vomiting syndrome (CVS) is an idiopathic disorder of gut-brain interaction characterized by recurrent bouts of nausea and vomiting. Although CVS negatively impacts quality of life (QOL), the determinants of impaired QOL among adult CVS sufferers are not fully understood. The unpredictability of CVS attacks may generate anticipatory anxiety and worsen quality of life in a substantial proportion of patients with CVS. Intolerance to uncertainty (IU) is a cognitive trait in which individuals experience distress when faced with unpredictable situations, particularly those with potentially negative consequences. Higher trait IU is a well-established vulnerability factor linked to the development of multiple psychiatric conditions, including anxiety. However, the extent to which higher IU is associated with impaired QOL in adults with CVS is not known. METHODS: To explore this issue, we surveyed 118 adult CVS patients and obtained demographic information, clinical features, reported healthcare utilization, and standardized assessments of IU, anxiety and panic, and QOL. KEY RESULTS: Adult CVS patients with higher IU did not report a greater frequency of CVS attacks or overall CVS-related healthcare utilization than those with lower IU. Yet, this group demonstrated substantially poorer physical and mental health-related QOL and higher rates of anxiety-spectrum disorders. CONCLUSIONS & INFERENCES: Higher degrees of IU are associated with increased anxiety and reduced QOL in patients with CVS. IU is a malleable cognitive trait that can be targeted by cognitive behavioral therapy (CBT). Our results suggest that some CVS patients may benefit from non-pharmacologic therapies such as CBT.