Gastroesophageal reflux disease: A clinical overview for primary care physicians.

OBJECTIVE: GERD is among the most common outpatient disease processes encountered by clinicians on a daily basis. This review provides insights about how to approach GERD in terms of disease management and treatment. METHODS: Review articles were searched using PUBMED and MEDLINE using criteria that included English language articles published in the last 5 years concerning studies carried out only in humans. The key words used in the searches were GERD, PPI, and erosive esophagitis. Recommendations from the American College of Gastroenterology are also included in this manuscript. RESULTS: The search resulted in ∼260 articles. The manuscript brings together and presents the results of recent recommendations from professional societies and recently published review articles on GERD. CONCLUSION: GERD is one of the most common diagnoses made by gastroenterologists and primary care physicians. It is important to recognize the typical and atypical presentations of GERD. This paper helps primary care physicians understand the disease's pathophysiology, and when, how, and with what to treat GERD before referring patients to gastroenterologists or surgeons.

Two year follow-up of Crohn's patients substituted to certolizumab anti-TNFa therapy: SAVANT 2.

The effectiveness of ant-TNF 'biologic' therapy in is well supported in the management of moderate to severe Crohn's Disease (CD). Our first 'SAVANT' study was to our knowledge the first study report one- year outcomes in patients (n=60) who switched from previous anti-TNFa treatment to Cimzia/Certolizumab. This current study (SAVANT 2) follows up on longer term outcomes and provides additional clinical and biochemical data that may contribute to therapeutic responses. This IRB approved study was a retrospective analysis of the initial patients included in SAVANT 1. Patients who were switched to TNF antagonist Certolizumab as an alternative biologic were followed an additional year. Retrospective consideration of immunomodulator use, smoking status and clinical data were also evaluated. Of 60 patients with moderate-severe CD who participated in the SAVANT 1 study, 15 patients were excluded due to inadequate follow up. 45 patients were studied for a total of two years following substitution with Certolizumab from prior anti TNF agent therapy. Clinical remission at 1 year was 75% (45/60) and 55% (25/45) at the second year. At the second year, 5 more patients had discontinued Certolizumab due to worse disease or adverse events, indicating a cumulative two-year failure rate of 33% (20/60). Smoking and concomitant use of immunomodulators were similar between 'success' and 'failure' groups. SAVANT 2, the first study to report long term outcomes of switching from Infliximab or Adalimumab to Certolizumab showed that at 2 years, 25 patient's maintained clinical remission. The discontinuation rates were 25 and 11% at years 1 & 2 respectively. The 5 patients who lost responsiveness after the first year were women, the majority of smoked. Additional prospective studies to assess the appropriateness and feasibility of biologic substitution are still needed.

Adverse reactions to infliximab and the outcome of desensitization.

BACKGROUND: Infliximab is a highly effective monoclonal antibody against tumor necrosis factor, which is a major inflammatory mediator in certain gastrointestinal, rheumatic, and skin diseases. In some patients, infliximab infusion causes systemic adverse reactions that often lead to discontinuation of therapy even in responsive patients. OBJECTIVE: To investigate the frequency and characteristics of adverse reactions to infliximab at the authors' institution and the outcome of their management, including desensitization. METHODS: This was a single-center retrospective study of patients who were treated with infliximab, primarily for inflammatory bowel disease, from January 1, 2000 to March 31, 2014. Data included age, sex, underlying disease, infliximab therapy duration before the first reaction, manifestation of reaction, onset, and management. RESULTS: There were 336 patients with inflammatory bowel disease who were treated with infliximab during the study period. Thirty patients (8.9%) developed a systemic adverse reaction to infliximab, which was discontinued in 15 patients (50%) and was continued in 3 patients after premedication and/or decreased infusion rate. Twelve patients (40%) underwent infliximab desensitization with gradually increasing doses starting at a dilution of 0.1 mg/mL to reach the full treatment dose over approximately 4 to 6 hours. It was successful in all 12 patients, who continued to receive up to 26 infliximab infusions, mostly without premedication. CONCLUSION: Infliximab can trigger systemic reactions that hinder its administration. The present desensitization protocol appears to be safe and effective and it can be considered in patients whose inflammatory bowel disease responds well to infliximab but who develop systemic adverse reactions.

Association of statins with nonalcoholic fatty liver disease in patients with diabetes.

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in patients with diabetes; limited data suggested that statins may reduce the risk of NAFLD progression. This study aimed to examine the association between statins and the development or progression of NAFLD in veterans with diabetes. In a new-user negative control design, we conducted a retrospective propensity score (PS)-matched cohort study of patients with diabetes between 2003 and 2015. After excluding patients with other causes of liver disease, we formed PS using 85 characteristics. The primary outcome was a composite NAFLD progression outcome. Primary analysis examined odds of outcome in PS-matched cohort. Post-hoc analysis included a PS-matched cohort of statin users with intensive lowering of low-density lipoprotein-cholesterol (LDL-C) vs low-intensity lowering. We matched 34,102 pairs from 300,739 statin users and 38,038 non-users. The composite outcome occurred in 8.8% of statin users and 8.6% of non-users (odds ratio (OR) 1.02, 95% confidence interval (95% CI) 0.97-1.08). In the post-hoc analysis, intensive lowering of LDL-C compared to low-intensity showed increased NAFLD progression (OR 1.21, 95% CI 1.13-1.30). This study showed that statin use in patients with diabetes was not associated with decreased or increased risk of NAFLD progression. Intensive LDL-C lowering, compared to low-intensity LDL-C lowering, was associated with an increased risk of NAFLD progression.

Improved Healthcare Access Reduces Requirements for Surgery in Indigent IBD Patients Using Biologic Therapy: A 'Safety-Net' Hospital Experience.

Low socioeconomic status (SES) is associated with greater morbidity and increased healthcare resource utilization (HRU) in IBD. We examined whether a financial assistance program (FAP) to improve healthcare access affected outcomes and HRU in a cohort of indigent IBD patients requiring biologics. IBD patients (>18 years) receiving care at a 'safety-net' hospital who initiated biologics as outpatients between 1 January 2010 and 1 January 2019 were included. Patients were divided by FAP status. Patients without FAP had Medicare, Medicaid, or commercial insurance. Primary outcomes were steroid-free clinical remission at 6 and 12 months. Secondary outcomes were surgery, hospitalization, and ED utilization. Multivariate logistic regression was used to calculate odds ratio (OR) and 95% confidence interval (CI). Decision tree analysis (DTA) was also performed. We included 204 patients with 258 new biologic prescriptions. FAP patients had less complex Crohn's disease (50.7% vs. 70%, p = 0.033) than non-FAP patients. FAP records indicated fewer prior surgeries (19.6% vs. 38.4% p = 0.003). There were no statistically significant differences in remission rates, disease duration, or days between prescription and receipt of biologics. In multivariable logistic regression, adjusting for baseline demographics and disease severity variables, FAP patients were less likely to undergo surgery (OR: 0.28, 95% CI [0.08−0.91], p = 0.034). DTA suggests that imaging utilization may shed light on surgical differences. We found FAP enrollment was associated with fewer surgeries in a cohort of indigent IBD patients requiring biologics. Further studies are needed to identify interventions to address healthcare disparities in IBD.

Favorable Outcomes Combining Vedolizumab With Other Biologics or Tofacitinib for Treatment of Inflammatory Bowel Disease.

Background: Combining advanced therapies may improve outcomes in inflammatory bowel disease (IBD), but there are little data on the effectiveness and safety of this approach. Methods: We examined outcomes of patients who received vedolizumab in combination with another biologic or tofacitinib between 2016 and 2020. Results: Fourteen patients (10 ulcerative colitis [UC], 3 Crohn disease, 1 indeterminate colitis) received a combination of advanced therapies. Vedolizumab was combined with tofacitinib in 9 patients, ustekinumab in 3, and adalimumab in 2. Median follow-up on combination therapy was 31 weeks. Normalization of C-reactive protein (CRP) or fecal calprotectin (<5 mg/L and <150 µg/g, respectively) was achieved in 56% (5/9) and 50% (4/8) of patients. Paired median CRP decreased from 14 mg/L to <5 mg/L with combination therapy (n = 9, P = 0.02), and paired median calprotectin from 594 µg/g to 113 µg/g (n = 8, P = 0.12). Among patients with UC, paired median Lichtiger score decreased from 9 to 3 (n = 7, P = 0.02). Prednisone discontinuation was achieved in 67% (4/6) of prednisone-dependent patients. There were 4 infections: 2 required hospitalization (rotavirus, Clostridium difficile), and 2 did not (pneumonia, sinusitis). During follow-up, 5/14 patients discontinued combination therapy (2 nonresponse; 1 improvement and de-escalation; 1 noninfectious adverse effect; 1 loss of coverage). Conclusions: In this retrospective case series of a cohort with refractory IBD, combining vedolizumab with other biologics or tofacitinib improved inflammatory markers, reduced clinical disease activity and steroid use, and was well tolerated.

Risk Stratification in Post-ERCP Pancreatitis: How Do Procedures, Patient Characteristics and Clinical Indicators Influence Outcomes?

BACKGROUND: Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) remains common, and severe complications are associated with ERCP. There is no previous study detailing the effect of race and gender in a US-based population on risk of PEP. METHODS: Data were collected on 269 "first-performed" consecutive ERCPs followed by division by race (White vs. African-American) and sex (Female vs. Male). A total of 53 probable risk factors were evaluated by uni- and multivariate analysis followed by outcomes expressed as an odds ratio (OR) (with a 95% confidence interval, 95% CI). Finally, a principal component analysis was performed to construct a risk prediction model for PEP, which can be used by clinicians at bedside. RESULTS: After analyzing the risk factors based on race and gender-based groups, Caucasian males with PEP are more likely to have prior history of pancreatitis (p = 0.009), lower hemoglobin (p = 0.02)/blood urea nitrogen (BUN) (p = 0.01)/creatinine before ERCP (p = 0.07) and lower BUN (p = 0.01)/creatinine after ERCP (p = 0.07), while Caucasian females with PEP are more likely to have higher white blood cell (WBC) count before ERCP (p = 0.08) and lower amylase (p = 0.10)/bilirubin (p = 0.09)/aspartate aminotransferase (AST) after ERCP (p = 0.08). African-American males with PEP are more likely to have lower weight (p = 0.001)/smaller height (p = 0.0005)/lower alkaline phosphatase (p = 0.002)/AST (p = 0.04)/alanine transaminase (ALT) (p = 0.03) before ERCP and lower alkaline phosphatase (p = 0.002)/AST (p = 0.01)/ALT (p = 0.004) after ERCP, while African-American females with PEP are more likely to have prior history of pancreatitis (p = 0.004)/higher lipase before (p = 0.0001) and after (p = 0.05) ERCP along with increased risk with pancreatic duct cannulation (p = 0.0001) and injection (p = 0.0001)/biliary sphincterotomy (p = 0.0001). Importantly, prior history of ERCP, elevated AST after ERCP, and BUN prior to ERCP were found to be important clinical features predicting post-ERCP pancreatitis. To our knowledge, this is a first known attempt at developing a risk scoring system for PEP in a US population with decision tree learning. CONCLUSIONS: It is very evident that both patient and procedure-related risk factors vary by race and gender in the US population, leading to the development of a new risk assessment tool for PEP that can be used in clinical practice. We need to follow up with a larger prospective study to validate this novel race and gender-based risk scoring system for PEP.

African-American inflammatory bowel disease in a Southern U.S. health center.

BACKGROUND: Inflammatory Bowel Diseases (IBD) remain significant health problems in the US and worldwide. IBD is most often associated with eastern European ancestry, and is less frequently reported in other populations of African origin e.g. African Americans ('AAs'). Whether AAs represent an important population with IBD in the US remains unclear since few studies have investigated IBD in communities with a majority representation of AA patients. The Louisiana State University Health Sciences Center in Shreveport (LSUHSC-S) is a tertiary care medical center, with a patient base composed of 58% AA and 39% Caucasian (W), ideal for evaluating racial (AA vs. W) as well and gender (M vs. F) influences on IBD. METHODS: In this retrospective study, we evaluated 951 visits to LSUHSC-S for IBD (between 2000 to 2008) using non-identified patient information based on ICD-9 medical record coding (Crohn's disease 'CD'-555.0- 555.9 and ulcerative colitis 'UC'-556.0-556.9). RESULTS: Overall, there were more cases of CD seen than UC. UC and CD affected similar ratios of AA and Caucasian males (M) and females (F) with a rank order of WF > WM > AAF > AAM. Interestingly, in CD, we found that annual visits per person was the highest in AA M (10.7 ± 1.7); significantly higher (* -p < 0.05) than in WM (6.3 ± 1.0). Further, in CD, the female to male (F: M) ratio in AA was significantly higher (*- p < 0.05) (1.9 ± 0.2) than in Caucasians (F:M = 1.3 ± 0.1) suggesting a female dominance in AACD; no differences were seen in UC F: M ratios. CONCLUSION: Although Caucasians still represent the greatest fraction of IBD (~64%), AAs with IBD made up >1/3 (36.4%) of annual IBD cases from 2000-2008 at LSUHSC-S. Further studies on genetic and environments risks for IBD risk in AAs are needed to understand differences in presentation and progression in AAs and other 'non-traditional' populations.

Association of myocardial bridge and Takotsubo cardiomyopathy: a case report and literature review.

A woman presented with chest pain following emotional stress. Investigations showed acute ST-segment elevation, myocardial infarction, and elevated serum troponin. Emergency heart catheterization showed left anterior descending artery myocardial bridging, apical ballooning consistent with takotsubo cardiomyopathy (TTC), and decreased ejection fraction. Two days later, echocardiogram demonstrated near normalization of ventricular function.The etiology of TTC is not known but may include a stress-related surge of catecholamines or epicardial coronary spasm. Other case series reported an association of myocardial bridge and TTC. Catecholamines surge during stress might contribute to both diseases resulting in an apparent association; alternatively, a symptomatic myocardial bridge may be a contributing factor in worsening TTC.

Autoimmune Hepatitis (AIH) in Acquired Immune Deficiency Syndrome (AIDS): A Case Report and Review of Literature.

The common causes of abnormal liver chemistries in human immunodeficiency virus (HIV) infected patients are multifactorial. Diagnosis of autoimmune hepatitis (AIH) in HIV infected patients is intriguing but data is scarce. Unmasking of AIH during immune reconstitution in HIV patients after starting antiretroviral therapy is reported but not with advanced acquired immunodeficiency syndrome (AIDS). Here we present a fascinating case of 32-year-old African-American man with advanced AIDS who presented with elevated transaminases. He was diagnosed with AIH before starting antiretroviral therapy and successfully treated with prednisolone and azathioprine with antiretroviral therapy despite very low CD4 count.

Cholestatic liver diseases: An era of emerging therapies.

Recently the field of cholestasis has expanded enormously reflecting an improved understanding of the molecular mechanisms underlying bile secretion and its perturbation in chronic cholestatic disease. Novel anti-cholestatic therapeutic options have been developed for patients not favorably responding to ursodeoxycholic acid (UDCA), the current standard treatment for cholestatic liver disease. Important novel treatment targets now also include nuclear receptors involved in bile acid (BA) homoeostasis like farnesoid X receptor and G protein-coupled receptors e.g., the G-protein-coupled BA receptor "transmembrane G coupled receptor 5". Fibroblast growth factor-19 and enterohepatic BA transporters also deserve attention as additional drug targets as does the potential treatment agent norUDCA. In this review, we discuss recent and future promising therapeutic agents and their potential molecular mechanisms in cholestatic liver disorders.

Interferon-gamma depresses human intestinal smooth muscle cell contractility: Relevance to inflammatory gut motility disturbances.

AIM/BACKGROUND: In addition to absorptive disturbances, inflammatory bowel diseases (IBD) perturb normal contractility of intestinal smooth muscle. Such motility disturbances may reflect both nervous alterations and increased abundance of cytokines (e.g. IL-1ß, TNF-α, and IFN-γ), which impair normal intestinal smooth muscle structure and function. In a previous study, we reported that IL-1ß decreased mesenteric muscular contractility, consistent with cytokine-mediated changes in contraction present in IBD. Here, we considered the impact of pro-inflammatory cytokines on human intestinal smooth muscle cell (HISMC) contractility in vitro, which might provide a method for evaluating treatments for IBD. MATERIALS AND METHODS: We used an in vitro tonic contraction assay to study how HISMC contractility was affected by cell density, serum, and cytokines (IL-1ß, TNF-α, and IFN-γ). MTT (3-(4, 5-dimethyl thiazolyl-2)-2, 5-diphenyltetrazolium bromide) and wound healing analyses were also used to measure cell proliferation and migration in HISMC in response to IFN-γ. KEY FINDINGS: We found that IFN-γ (but not IL-1ß or TNF-α) significantly depressed HISMC tonic contractility over six days. IFN-γ also decreased HISMC proliferation, migration, and smooth muscle F-actin expression in a dose-dependent manner (studied at 4 days). SIGNIFICANCE: Our studies indicate that IFN-γ dose and time-dependently reduces normal HISMC contractility, motility and proliferation which may contribute to dysmotility observed in GI inflammatory disorders and that IFN-γ therapeutics might restore normal HISMC contractility impaired in IBD.

Short-Term Use of Upadacitinib in Combination With Biologic Therapy for Inducing Clinical Remission in Patients With Active Inflammatory Bowel Disease.

We report that upadacitinib intended for short-term use in combination with biologic therapy appeared to be effective in inducing steroid-free clinical remission in patients with active inflammatory bowel disease, but a substantial proportion of patients required extended use.

3D Printing for Bio-Synthetic Biliary Stents.

Three-dimensional (3D) printing is an additive manufacturing method that holds great potential in a variety of future patient-specific medical technologies. This project validated a novel crosslinked polyvinyl alcohol (XL-PVA) 3D printed stent infused with collagen, human placental mesenchymal stem cells (PMSCs), and cholangiocytes. The biofabrication method in the present study examined 3D printing and collagen injection molding for rapid prototyping of customized living biliary stents with clinical applications in the setting of malignant and benign bile duct obstructions. XL-PVA stents showed hydrophilic swelling and addition of radiocontrast to the stent matrix improved radiographic opacity. Collagen loaded with PMSCs contracted tightly around hydrophilic stents and dense choloangiocyte coatings were verified through histology and fluorescence microscopy. It is anticipated that design elements used in these stents may enable appropriate stent placement, provide protection of the stent-stem cell matrix against bile constituents, and potentially limit biofilm development. Overall, this approach may allow physicians to create personalized bio-integrating stents for use in biliary procedures and lays a foundation for new patient-specific stent fabrication techniques.

Pyogenic Liver Abscess Caused by Methicillin-Susceptible Staphylococcus aureus in a 21-Year-Old Male.

Liver abscesses are the most common types of visceral abscesses. Pyogenic liver abscesses, a particular type of liver abscesses, are uncommonly encountered. We present a rare case of pyogenic liver abscess caused by methicillin-susceptible Staphylococcus aureus in a young man. A 21-year- old man presented from prison to the hospital with fever, nausea, vomiting, diarrhea, and abdominal pain for five days. Labs were significant for leukocytosis with predominant neutrophilia and elevated liver enzymes. CT abdomen with contrast revealed an 8.4 cm multiloculated right hepatic mass extending to the kidney. Patient was started on broad spectrum antibiotics, given septic presentation. Peripheral blood cultures returned positive for methicillin-susceptible Staphylococcus aureus (MSSA). The culture from percutaneous drainage also revealed MSSA. He received a total of four weeks of IV Nafcillin therapy along with drainage of his abscess via percutaneous catheter. Follow-up revealed clinical resolution. This case highlights the importance of obtaining an aspirate from the liver abscess to better guide treatment strategy. Clinicians must consider broadening antibiotic coverage to include gram-positive organisms if the patient presents with severe illness and risk factors for Staphylococcus aureus infections.

Gastrointestinal Bleeding Secondary to Portal Hypertensive Duodenopathy in a Patient with Decompensated Liver Cirrhosis.

With alcoholic cirrhosis and nonalcoholic fatty liver disease continuously on the rise in the United States, there is also a corresponding rise in portal hypertension. Portal hypertensive duodenopathy (PHD) is a complication of portal hypertension not commonly seen in cirrhotic patients. We present a case of a 46-year-old man who presented with decompensated liver cirrhosis secondary to gastrointestinal bleed. The patient underwent esophagogastroduodenoscopy (EGD) with findings indicative of PHD. Patient subsequently underwent transjugular intrahepatic portosystemic shunt (TIPS) with resolution of gastrointestinal bleed. We highlight TIPS as a management strategy in patients with PHD for whom less invasive measures are not effective.

Liver Cholestasis Secondary to Syphilis in an Immunocompetent Patient.

Liver involvement is a known feature of secondary syphilis. The prevalence of hepatitis in secondary syphilis ranges broadly from 1 to 50%. We report a case of a 37-year-old man with type 1 diabetes mellitus and sickle cell trait presenting with jaundice and acute liver cholestasis. Abdominal ultrasound revealed mild hepatic fatty infiltration. RPR and Treponema pallidum IgG results were positive with a reflex titer of 1:64. Liver biopsy revealed chronic hepatitis with normal hepatic architecture, Kupffer cell hyperplasia, hepatic cholestasis, and ductal proliferation suggestive of syphilitic hepatitis.

High-throughput scaffold-free microtissues through 3D printing.

BACKGROUND: Three-dimensional (3D) cell cultures and 3D bioprinting have recently gained attention based on their multiple advantages over two-dimensional (2D) cell cultures, which have less translational potential to recapitulate human physiology. 3D scaffold supports, cell aggregate systems and hydrogels have been shown to accurately mimic native tissues and support more relevant cell-cell interactions for studying effects of drugs and bioactive agents on cells in 3D. The development of cost-effective, high-throughput and scaffold-free microtissue assays remains challenging. In the present study, consumer grade 3D printing was examined as a fabrication method for creation of high-throughput scaffold-free 3D spheroidal microtissues. RESULTS: Consumer grade 3D printing was capable of forming 96-well cell culture inserts to create scaffold-free microtissues in liquid suspensions. The inserts were seeded with human glioblastoma, placental-derived mesenchymal stem cells, and intestinal smooth muscle cells. These inserts allowed for consistent formation of cell density-controllable microtissues that permit screening of bioactive agents. CONCLUSION: A variety of different cell types, co-cultures, and drugs may be evaluated with this 3D printed microtissue insert. It is suggested that the microtissue inserts may benefit 3D cell culture researchers as an economical assay solution with applications in pharmaceuticals, disease modeling, and tissue-engineering.

Pseudohyponatraemia secondary to hyperlipidaemia in obstructive jaundice.

A 44-year-old man with uncontrolled diabetes and chronic pancreatitis presented with abdominal pain, jaundice and unintentional weight loss. Laboratory investigations were significant for hyponatraemia, an obstructive pattern of liver enzymes. Imaging was consistent with intrahepatic and extrahepatic biliary obstruction, and endoscopic evaluation revealed a long common bile duct stricture. Intravascular volume depletion, beer potomania and syndrome of inappropriate antidiuretic hormone (with concern for biliary or pancreatic malignancy) were considered in the work-up for the aetiology of the hyponatraemia. After 4 days of conventional treatment, hyponatraemia persisted. Lipid panel obtained revealed very high levels of total cholesterol. The patient underwent a successful biliary diversion and reconstruction surgery. Follow-up after 3 months showed a clinically stable patient with resolution of elevated liver enzymes, hyperlipidaemia and hyponatraemia. We illustrate this rare case of hyponatraemia secondary to hyperlipidaemia in obstructive biliary cholestasis. It is important for physicians to thoroughly investigate the aetiology of hyponatraemia at its onset.

Non-celiac gluten sensitivity: All wheat attack is not celiac.

Currently, 1% of the United States population holds a diagnosis for celiac disease (CD), however, a more recently recognized and possibly related condition, "non-celiac gluten sensitivity" (NCGS) has been suggested to affect up to 6% of the United States public. While reliable clinical tests for CD exist, diagnosing individuals affected by NCGS is still complicated by the lack of reliable biomarkers and reliance upon a broad set of intestinal and extra intestinal symptoms possibly provoked by gluten. NCGS has been proposed to exhibit an innate immune response activated by gluten and several other wheat proteins. At present, an enormous food industry has developed to supply gluten-free products (GFP) with GFP sales in 2014 approaching $1 billion, with estimations projecting sales to reach $2 billion in the year 2020. The enormous demand for GFP also reflects a popular misconception among consumers that gluten avoidance is part of a healthy lifestyle choice. Features of NCGS and other gluten related disorders (e.g., irritable bowel syndrome) call for a review of current distinctive diagnostic criteria that distinguish each, and identification of biomarkers selective or specific for NCGS. The aim of this paper is to review our current understanding of NCGS, highlighting the remaining challenges and questions which may improve its diagnosis and treatment.