Cognitive impairment in coeliac disease improves on a gluten-free diet and correlates with histological and serological indices of disease severity

Editorial: Peering through the fog-New tools to assess neurocognitive symptoms in coeliac disease

This article is linked to Knowles et al paper. To view this article, visit https://doi.org/10.1111/apt.17942

Development and validation of a brain fog scale for coeliac disease

BACKGROUND

Brain fog is a subjective cognitive impairment commonly reported in coeliac disease. A standardised tool to define and assess it is an important unmet need.

AIMS

To develop a patient-informed tool to assess brain fog in coeliac disease to support clinical care, research and drug development.

METHODS

A pilot online study defined patient descriptors of brain fog. A second study evaluated the factor structure and performance of the scale across two-time points ('Now' and in the 'Past week'). One month later, participants were invited to repeat the study with two online cognitive processing tests, the Stroop task and the trail making test.

RESULTS

Among adults with treated coeliac disease, 37 (91.9% F) participated in the pilot study and 510 (88.8% F) in the second study of whom 99 repeated the study 1 month later with 51 completing cognitive testing. The most common brain fog descriptors were 'difficulty focusing', 'difficulty thinking' and 'difficulty finding the right words and communicating'. The 12-item scale reflects 'cognitive impairment' and 'somatic and affective experience' and demonstrates strong psychometric properties. It tracked with patients report of brain fog being present or absent across two-time points. It did not significantly correlate with the cognitive tests.

CONCLUSION

The brain fog assessment and severity scale is the first patient-informed clinical outcomes assessment tool measuring brain fog in coeliac disease. It is brief and validated for two time-based formats. Further research coupling it with biomarker discovery is needed to confirm its validity as a predictor of cognitive performance.

Brain fog in central disorders of hypersomnolence: a review

Brain fog is an undefined term describing a cluster of symptoms related to fatigue and impaired memory, attention, and concentration. Brain fog or brain fog-like symptoms have been reported in central disorders of hypersomnolence and in a range of seemingly unrelated disorders, including coronavirus disease 2019, major depressive disorder, multiple sclerosis, lupus, and celiac disease. This narrative review summarizes current evidence and proposes a consensus definition for brain fog. Brain fog is prevalent in narcolepsy and idiopathic hypersomnia, with more than three-quarters of patients with either disorder reporting this symptom in a registry study; it has also been reported as particularly difficult to treat in idiopathic hypersomnia. Studies directly evaluating brain fog are rare; tools for evaluating this symptom cluster typically are patient reports, with few objective measures validated in any disorder. Evaluating brain fog is further complicated by confounding symptoms, such as excessive daytime sleepiness, which is a hallmark of hypersomnolence disorders. No treatments specifically address brain fog. The paucity of literature, assessment tools, and medications for brain fog highlights the need for research leading to better disambiguation and treatment. Until a clear consensus definition is established, we propose brain fog in hypersomnia disorders be defined as a cognitive dysfunction that may or may not be linked with excessive sleepiness, related to an underlying neuronal dysfunction, which reduces concentration and impairs information processing, leading to a complaint of lack of clarity of mental thinking and awareness.

CITATION

Rosenberg R, Thorpy MJ, Doghramji K, Morse AM. Brain fog in central disorders of hypersomnolence: a review. J Clin Sleep Med. 2024;20(4):643-651.

Childhood Apraxia of Speech: Exploring Gluten Sensitivity and Changes in Glutamate and Gamma-Aminobutyric Acid Plasma Levels

BACKGROUND

Individuals with childhood apraxia of speech (CAS) were reported to have genetic variations related to gluten sensitivity and some neuroanatomic changes, which could be associated with alterations in neurotransmitters levels such as glutamate and gamma-aminobutyric acid (GABA). The aim was to measure the levels of antigliadin immunoglobulin A (IgA) antibody, glutamate, and GABA in the plasma of children with CAS compared with children with delayed language development (DLD) and neurotypical (NT) children.

METHODS

The participants (N = 120) were in three groups: Group I for CAS (N = 30), Group II for DLD (N = 60), and Group III for NT (N = 30). The abilities of children in Groups I and II were evaluated. The plasma levels of antigliadin IgA, glutamate, and GABA were determined by enzyme-linked immunosorbent assay.

RESULTS

The intelligence quotient and expressive language age in Group I were low compared with Group II (P = 0.001; 0.004). The levels of antigliadin IgA and glutamate in Group I were higher compared with the other two groups, whereas the level of GABA was lower (P < 0.0001). An imbalance between glutamate and GABA was found in Group I. In Group II, no measures differed from NTs except lower GABA levels (P = 0.0007).

CONCLUSIONS

The elevated levels of antigliadin IgA antibody and glutamate demonstrated high sensitivity and specificity, differentiating children with CAS from children with DLD and NT children. The low levels of GABA contributed to the imbalance between the excitatory and inhibitory neurotransmitters' levels detected in children with CAS.

Brain Fog: a Narrative Review of the Most Common Mysterious Cognitive Disorder in COVID-19

It has been more than three years since COVID-19 impacted the lives of millions of people, many of whom suffer from long-term effects known as long-haulers. Notwithstanding multiorgan complaints in long-haulers, signs and symptoms associated with cognitive characteristics commonly known as "brain fog" occur in COVID patients over 50, women, obesity, and asthma at excessive. Brain fog is a set of symptoms that include cognitive impairment, inability to concentrate and multitask, and short-term and long-term memory loss. Of course, brain fog contributes to high levels of anxiety and stress, necessitating an empathetic response to this group of COVID patients. Although the etiology of brain fog in COVID-19 is currently unknown, regarding the mechanisms of pathogenesis, the following hypotheses exist: activation of astrocytes and microglia to release pro-inflammatory cytokines, aggregation of tau protein, and COVID-19 entry in the brain can trigger an autoimmune reaction. There are currently no specific tests to detect brain fog or any specific cognitive rehabilitation methods. However, a healthy lifestyle can help reduce symptoms to some extent, and symptom-based clinical management is also well suited to minimize brain fog side effects in COVID-19 patients. Therefore, this review discusses mechanisms of SARS-CoV-2 pathogenesis that may contribute to brain fog, as well as some approaches to providing therapies that may help COVID-19 patients avoid annoying brain fog symptoms.

Cognitive Impairment in Celiac Disease Patients: Scoping Review Exploring Psychological Triggers in a Chronic Condition

Celiac disease (CD), also known as gluten-sensitive enteropathy, is an inflammatory autoimmune reaction triggered by ingestion of gluten in genetically predisposed subjects. Celiac disease is often associated with a wide range of disorders, caused by immune responses and by malabsorption with subsequent nutritional deficiencies. Prevalent neurologic manifestations are ataxia, epilepsy, cerebral calcification, cerebral white matter lesions, peripheral neuropathy and myopathy, but also cognitive impairment. The study aimed to identify emerging and urgent research domains in order to establish a CD-specific patient-tailored protocol that includes both psychological and neuropsychological evaluations. We performed a systematic search of MEDLINE, PubMed, SCOPUS, Web of Science and Cochrane library in November 2022. We conducted a descriptive analysis of the characteristics of the included literature. Based on the exclusion/inclusion criteria, a total of seven articles were included in the scoping review process. This review demonstrated the lack of research on CD-related cognitive impairment key features and tries to focus on both cognitive and psychological manifestations as well as their two-way interaction. We tried to establish the specific areas involved, in order to have a comprehensive view of this condition and trying to determine a correct way of assessing CD cognitive impairment and its correlations with psychological distress and personal coping skills to a chronic condition. Nevertheless, research on this topic is progressively increasing and future studies should address specific key points.

A Clinical Investigation on ADHD-Traits in Childhood Celiac Disease

OBJECTIVE

There are no definitive results about either the presence of exact comorbidity between celiac disease (CD) and attention-deficit/hyperactivity disorders (ADHD) or etiology. We intend to screen ADHD-related cognitive and behavioral traits in children with biopsy-proven CD and investigate the possible association of these traits with certain vitamin levels, body-mass index, and gluten-free diet (GFD) compliance.

METHOD

A total of 85 children with biopsy-proven CD (the ages of 8-18 years) were compared with age and sex-matched 72 healthy controls in terms of demographics, psychiatric symptoms, certain vitamin levels, and anthropometric measurements.

RESULTS

ADHD-like cognitive issues, such as inattention and learning difficulties, as well as psychosomatic symptoms and poor prosocial behavior, were all associated with GFD noncompliance in childhood CD.

CONCLUSION

Untreated CD may predispose to ADHD-resembling symptoms. Physicians should be aware of the probability of ADHD misdiagnosing due to ADHD-resembling cognitive and behavioral traits in untreated CD.

New Developments in Celiac Disease Treatment

Celiac disease (CD) is a common autoimmune disease affecting around 1% of the population. It consists of an immune-mediated enteropathy, triggered by gluten exposure in susceptible patients. All patients with CD, irrespective of the presence of symptoms, must endure a lifelong gluten-free diet (GFD). This is not an easy task due to a lack of awareness of the gluten content in foods and the extensive incorporation of gluten in processed foods. Furthermore, a GFD imposes a sense of limitation and might be associated with decreased quality of life in CD patients. This results in gluten contamination in the diet of four out of five celiac patients adhering to a GFD. Furthermore, one in three adult patients will report persistent symptoms and two in three will not achieve full histological recovery when on a GFD. In recent years, there has been extensive research conducted in the quest to find the holy grail of pharmacological treatment for CD. This review will present a concise description of the current rationale and main clinical trials related to CD drug therapy.

Celiac disease and upper secondary school achievement in Sweden A retrospective cohort study

BACKGROUND

Both undiagnosed celiac disease and some chronic childhood diseases are associated with lower academic achievement. However, there is little knowledge of achievements in those diagnosed with celiac disease. Our aim was to investigate school achievements in upper secondary school among Swedish adolescents with celiac disease.

METHODS

We performed a retrospective cohort study using register data. We analyzed choice of upper secondary school program, completion of upper secondary school including achievements of basic eligibility for college/university, and final grade in individuals with celiac disease diagnosed before 15 years of age, born 1991-97. We compared with the Swedish population of the same birth years. Analyses were adjusted for sex, year of birth, living region at 17 years of age, and parental education as well as income.

RESULTS

The cohort included 734 074 individuals, whereof 3 257 (62% females) with celiac disease. There was no significant difference in choice of upper secondary school program. No significant difference was found in completion or achieving basic eligibility for college/university in adjusted analyses. The mean final grade in the celiac disease group was 13.34 (standard deviation 4.85) compared to 12.78 (standard deviation 5.01) in the reference population (p < 0.001), out of a maximum of 20. The effect of celiac disease on final grade remained in adjusted analyses (p = 0.012).

CONCLUSIONS

We found that diagnosed celiac disease does not negatively affect school achievements in upper secondary school. This finding suggests the diagnosis, treatment and follow-up programs of celiac disease could reverse potential deleterious academic processes.

Celiac Disease and Neurological Manifestations: From Gluten to Neuroinflammation

Celiac disease (CD) is a complex multi-organ disease with a high prevalence of extra-intestinal involvement, including neurological and psychiatric manifestations, such as cerebellar ataxia, peripheral neuropathy, epilepsy, headache, cognitive impairment, and depression. However, the mechanisms behind the neurological involvement in CD remain controversial. Recent evidence shows these can be related to gluten-mediated pathogenesis, including antibody cross-reaction, deposition of immune-complex, direct neurotoxicity, and in severe cases, vitamins or nutrients deficiency. Here, we have summarized new evidence related to gut microbiota and the so-called "gut-liver-brain axis" involved in CD-related neurological manifestations. Additionally, there has yet to be an agreement on whether serological or neurophysiological findings can effectively early diagnose and properly monitor CD-associated neurological involvement; notably, most of them can revert to normal with a rigorous gluten-free diet. Moving from a molecular level to a symptom-based approach, clinical, serological, and neurophysiology data might help to disentangle the many-faceted interactions between the gut and brain in CD. Eventually, the identification of multimodal biomarkers might help diagnose, monitor, and improve the quality of life of patients with "neuroCD".

Effects of different environmental intervention durations on the intestinal mucosal barrier and the brain-gut axis in rats with colorectal cancer

An enriched environment (EE) is a promising strategy for protecting the intestinal mucosal barrier and regulating the brain-gut axis, but the optimal EE intervention duration is unknown. Here, different EE intervention durations were applied to assess the optimal intervention duration in rats with colorectal cancer. We used a rat model of 1, 2-dimethylhydrazine-induced colorectal cancer. The rats were housed in an EE for 0, 2, 4, 8 weeks and 8-week blank group. The intestinal mucosa and serum TNF-α, IL-6, IL-10, ATP, CRF, and occludin levels and bacterial translocation (BT) were measured, and the intestinal mucosa morphology was evaluated. In 8 weeks, the effect of tumor on intestinal mucosal barrier was not obvious and the EE had a greater impact on it. Eight weeks of EE was more beneficial to the intestinal mucosal mechanical barrier than 2 or 4 weeks of intervention. A significant difference in BT was found between the 4- and 8-week groups. Overall, the analysis of inflammatory factor regulation revealed that the two blank groups exhibited the worst effect, and the intervention effect at 8 weeks was better than that at 2 and 4 weeks. CRF at 4 weeks was higher than that at 8-week blank group. The effect of 8-week intervention duration on the intestinal mucosal barrier was generally better than that of 2- and 4-week durations and intervention within 4 weeks can help to stabilize and promote the secretion of brain gut peptide, but the effect of different intervention durations on the brain-gut peptide levels was not obvious. In the future, we can further explore the molecular biological mechanism of the effect of different EE intervention durations on the intestinal mucosal barrier and analyze the effect of an EE on other brain-gut peptides.

Gluten-induced Neurocognitive Impairment: Results of a Nationwide Study

GOALS

This study aimed to understand the neurocognitive symptoms associated with gluten exposure in individuals with self-reported celiac disease (CD) and nonceliac gluten sensitivity (NCGS).

BACKGROUND

While gluten-induced neurocognitive impairment (GINI; eg, "celiac fog" or "brain fog") is commonly described by individuals with CD and NCGS, there are little data regarding the prevalence and symptoms associated with these experiences.

STUDY

A 9-question online survey was accessed by 1396 individuals (1143 with CD; 253 with NCGS). Forced choice and free-response questions were asked of participants to obtain a description of neurocognitive symptoms experienced after gluten ingestion. Free-response answers were coded using a coding structure developed based on the Health-Related Quality of Life Instrument.

RESULTS

The majority of survey participants (89% of CD and 95% of NCGS) reported having GINI symptoms. When describing symptoms, the most common word descriptors for both groups were difficulty concentrating, forgetfulness, and grogginess. Timing of symptoms, including onset and symptom peak, were similar across the 2 groups. Coding of free responses found the most common references were to cognitive, physical, psychological, and overall quality of life impacts.

CONCLUSIONS

This survey suggests that GINI is common and may be severe in both individuals with CD and NCGS. Cognitive impairment and decline in physical functioning may be similar to that occurring in other illnesses, such as lupus. Clinical follow-up with both individuals with CD and NCGS should include assessment of GINI symptoms. Further research is warranted, including the development of a patient-reported outcome measure including neurocognitive effects of gluten exposure.

Review article: Systemic consequences of coeliac disease

BACKGROUND

The best-known symptoms of coeliac disease are related to the gastrointestinal tract, but the disease may also present with various systemic manifestations outside the intestine. Some of these consequences may remain permanent in undiagnosed individuals or if the diagnostic delay is prolonged. However, for many of the systemic manifestations, the scientific evidence remains scant and contradictory.

AIMS AND METHODS

We conducted a narrative review of the most thoroughly studied and clinically relevant systemic consequences of coeliac disease, especially those that could be prevented or alleviated by early diagnosis. The review is intended particularly for physicians encountering these patients in daily clinical practice.

RESULTS

The possible systemic consequences of coeliac disease extend to multiple organ systems, the best studied of which are related to skeletal, reproductive, cardiovascular and neurological systems. Furthermore, the disease is associated with an elevated risk of psychiatric comorbidities, non-Hodgkin lymphomas and intestinal adenocarcinoma.

CONCLUSIONS

The various systemic consequences of coeliac disease play a significant role in the overall health of patients. Early diagnosis and treatment with a gluten-free diet appear to be beneficial for most, but not all of these conditions. The possible negative metabolic and psychosocial effects of the diet should be acknowledged during follow-up.

The Association between ADHD and Celiac Disease in Children

Controversy around the association between celiac disease (CeD) and attention deficit hyperactive disorder (ADHD) was addressed by a systematic review in 2015, ultimately showing no association. Since 2015, there have been several studies showing an association between celiac disease and attention deficit hyperactive disorder. This is an updated systematic review. Background: Most experts agree on the recommendation to not screen as part of the standard of care for ADHD in persons with CeD or vice versa. Simultaneously, they propose that untreated patients with CeD and neurological symptoms such as chronic fatigue, inattention, pain, and headache could be predisposed to ADHD-like behavior, namely inattention (which may be alleviated by following a gluten-free diet). The inattentive subtype of ADHD that encompasses the symptoms of inattention is phenotypically heterogeneous, as it includes the clinical construct of sluggish cognitive tempo (SCT). SCT symptoms overlap with the neurological manifestations of CeD. Methods: A systematic search (PRISMA) of PubMed, Google Scholar, EMBASE, Web of Science, Stanford Lane, SCOPUS, and Ovid was conducted for articles up to 21 February 2022. Of these, 23 studies met the criteria. Results: Out of the 23 studies, 13 showed a positive association between ADHD and CeD. Most studies that showed a positive association had been published in the last five years. Inconsistencies in the results remain due to the heterogeneous methodology used, specifically for ADHD and the outcome questionnaires, as well as a lack of reporting on ADHD subtypes. Conclusion: There is an association between ADHD and celiac disease. The current methodological limitations will be lessened if we examine the subtypes of ADHD.

Does Alzheimer's disease stem in the gastrointestinal system?

Over the last decades, our knowledge of the key pathogenic mechanisms of Alzheimer's disease (AD) has dramatically improved. Regarding the limitation of current therapeutic strategies for the treatment of multifactorial diseases, such as AD, to be translated into the clinic, there is a growing trend in research to identify risk factors associated with the onset and progression of AD. Here, we review the current literature with a focus on the relationship between gastrointestinal (GI)/liver diseases during the lifespan and the incidence of AD, and discuss the possible mechanisms underlying the link between the diseases. We also aim to review studies evaluating the possible link between the chronic use of the most common GI medications and the future risk of AD development.

Physiological mechanisms of unexplained (functional) gastrointestinal disorders

Functional gastrointestinal disorders (FGIDs) encompass a range of complex conditions with similar clinical characteristics and no overt pathology. Recent recognition of sub-clinical pathologies in FGIDs, in conjunction with physiological and biochemical abnormalities including increased intestinal permeability, microbial profile alterations, differences in metabolites and extra-intestinal manifestations of disease, call into question the designation of these conditions as 'functional'. This is despite significant heterogeneity in both symptom profile and specifics of reported physiological abnormalities hampering efforts to determine defined mechanisms that drive onset and chronicity of symptoms. Instead, the literature demonstrates these conditions are disorders of homeostatic imbalance, with disruptions in both host and microbial function and metabolism. This imbalance is also associated with extraintestinal abnormalities including psychological comorbidities and fatigue that may be a consequence of gastrointestinal disruption. Given the exploitation of such abnormalities will be crucial for improved therapeutic selection, an enhanced understanding of the relationship between alterations in function of the gastrointestinal tract and the response of the immune system is of interest in identifying mechanisms that drive FGID onset and chronicity. Considerations for future research should include the role of sex hormones in regulating physiological functions and treatment responses in patients, as well as the importance of high-level phenotyping of clinical, immune, microbial and physiological parameters in study cohorts. There is opportunity to examine the functional contribution of the microbiota and associated metabolites as a source of mechanistic insight and targets for therapeutic modulation.

Gluten and FODMAPs Relationship with Mental Disorders: Systematic Review

Nowadays, gluten and FODMAP food components (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) are increasingly studied due to their possible relation with extraintestinal-associated conditions. In recent years, gluten-free diets (GFD) and low-FODMAP diets (LFD) are becoming more popular not only in order to avoid the food components that cause intolerances or allergies in some people, but also due to the direct influence of marketing movements or diet trends on feeding habits. Likewise, neurological and psychiatric diseases are currently of increasing importance in developed countries. For this reason, a bibliographic systematic review has been carried out to analyse whether there is a pathophysiological relationship between the dietary intake of gluten or FODMAPs with mental disorders. This review collects 13 clinical and randomized controlled trials, based on the PRISMA statement, which have been published in the last ten years. Based on these results, limiting or ruling out gluten or FODMAPs in the diet might be beneficial for symptoms such as depression, anxiety (7 out of 7 articles found any positive effect), or cognition deficiency (improvements in several cognition test measurements in one trial), and to a lesser extent for schizophrenia and the autism spectrum. Nevertheless, further studies are needed to obtain completely reliable conclusions.

Neurological Evaluation of Patients with Newly Diagnosed Coeliac Disease Presenting to Gastroenterologists: A 7-Year Follow-Up Study

We have previously shown that 67% of patients with newly diagnosed coeliac disease (CD) presenting to gastroenterologists have evidence of neurological dysfunction. This manifested with headache and loss of co-ordination. Furthermore 60% of these patients had abnormal brain imaging. In this follow-up study, we re-examined and re-scanned 30 patients from the original cohort of 100, seven years later. There was significant reduction in the prevalence of headaches (47% to 20%) but an increase in the prevalence of incoordination (27% to 47%). Although those patients with coordination problems at baseline reported improvement on the gluten free diet (GFD), there were 7 patients reporting incoordination not present at baseline. All 7 patients had positive serology for one or more gluten-sensitivity related antibodies at follow-up. In total, 50% of the whole follow-up cohort were positive for one or more gluten-related antibodies. A comparison between the baseline and follow-up brain imaging showed a greater rate of cerebellar grey matter atrophy in the antibody positive group compared to the antibody negative group. Patients with CD who do not adhere to a strict GFD and are serological positive are at risk of developing ataxia, and have a significantly higher rate of cerebellar atrophy when compared to patients with negative serology. This highlights the importance of regular review and close monitoring.

Long-term Intake of Gluten and Cognitive Function Among US Women

IMPORTANCE

Gluten avoidance has been suggested as having a benefit to cognitive health among the general population, given the link between gluten and cognitive impairment in patients with celiac disease. However, data are lacking in individuals without celiac disease.

OBJECTIVE

To examine whether gluten intake is associated with cognitive function in women without celiac disease.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included US women who participated in the longitudinal, population-based Nurses' Health Study II and had not previously or subsequently been diagnosed with celiac disease. Dietary data were collected from 1991 to 2015, and data on cognitive function were collected from 2014 to 2019. Data analysis was conducted from October 2020 to April 2021.

EXPOSURES

Energy-adjusted gluten intake, cumulatively averaged across questionnaire cycles prior to cognitive assessment.

MAIN OUTCOMES AND MEASURES

Three standardized cognitive scores assessed by the validated Cogstate Brief Battery: (1) psychomotor speed and attention score, (2) learning and working memory score, and (3) global cognition score. Higher scores indicated better performance.

RESULTS

The cohort included 13 494 women (mean [SD] age, 60.6 [4.6] years). The mean (SD) gluten intake was 6.3 (1.6) g/d. After controlling for demographic and lifestyle risk factors in linear regression, no significant differences in standardized cognitive scores (mean [SD], 0 [1]) by quintile of gluten intake were found across highest and lowest quintiles of gluten intake (psychomotor speed and attention: -0.02; 95% CI, -0.07 to 0.03; P for trend = .22; learning and working memory: 0.02; 95% CI, -0.03 to 0.07; P for trend = .30; global cognition: -0.002; 95% CI, -0.05 to 0.05; P for trend = .78). The null associations persisted after additional adjustment for major sources of dietary gluten (ie, refined grains or whole grains), comparing decile categories of gluten intake, using gluten intake updated at each previous questionnaire cycle, or modeling changes in gluten intake. Similarly, these associations were not materially altered in sensitivity analyses that excluded women who had reported cancer or dementia diagnosis or had not completed all dietary assessments.

CONCLUSIONS AND RELEVANCE

In this study, long-term gluten intake was not associated with cognitive scores in middle-aged women without celiac disease. Our results do not support recommendations to restrict dietary gluten to maintain cognitive function in the absence of celiac disease or established gluten sensitivity.

Brain fog and non-coeliac gluten sensitivity: Proof of concept brain MRI pilot study

AIMS

Non-Coeliac Gluten Sensitivity (NCGS) is poorly understood, particularly in terms of its neurological outcomes. We initially conducted a prospective postal survey to investigate its neurological presentation and symptom course. Results from this then motivated a follow-up pilot study utilising brain MRI to characterise potential diagnostic biomarkers for future research.

METHODS

Patients with NCGS were recruited from a specialist centre and completed a prospective postal questionnaire (N = 125). This summarised symptoms experienced, their severity and their course. Onset time was compared by Chi-squared analysis to data from the same centre concerning coeliac disease patients (N = 224). Five respondents on a strict gluten-free diet who self-reported brain fog then attended a pilot study, completing MR brain imaging/questionnaires before/after a gluten challenge. "Baseline" data were assessed for abnormalities, while symptom severity and cerebral blood flow (CBF) were compared before/after challenge.

RESULTS

Survey participants were aged 47 (85% female). Prevalence of neurological symptoms were: headaches (51%), brain fog (48%), balance issues (31%), tingling (19%). Median symptom resolution time was 48 hours, while onset was 90 minutes; onset pattern was not significantly different compared to CD patients (p = 0.322). Extra-intestinal symptoms worsened by 37%(±28) during a typical reaction. Predominantly non-statistical observations from the brain imaging study are discussed.

CONCLUSIONS

Neurological symptoms in NCGS are common, and onset time is comparable to that in CD. Brain imaging may be a useful future means of investigating physiological injury and responses to gluten in further study.

Association of ADHD and Celiac Disease: What Is the Evidence? A Systematic Review of the Literature

Objective: This article tries to answer the question whether or not there is evidence for a relationship between celiac disease (CD) and ADHD. A review of the current literature on this topic is provided. Method: PUBMED/MEDLINE, Web of Science, and Google scholar were searched to include all published trials on ADHD and CD (no date limitation, both noncontrolled and controlled trials). In addition, the reference list of included studies was screened to find other relevant articles. Results: Eight studies report a possible association between CD and ADHD; however, the results are inconsistent. Only three out of eight studies report a positive correlation between ADHD and CD. Conclusion: Up till now, there is no conclusive evidence for a relationship between ADHD and CD. Therefore, it is not advised to perform routine screening of CD when assessing ADHD (and vice versa) or to implement gluten-free diet as a standard treatment in ADHD.

Cognitive Impairment in Coeliac Disease with Respect to Disease Duration and Gluten-Free Diet Adherence: A Pilot Study

Cognitive deficit has been reported in coeliac disease (CD), but previous reports often study heterogenous samples of patients at multiple stages of the disease, or lack control data. Healthy controls (N = 21), newly diagnosed CD patients (NCD; N = 19) and established CD patients (ECD; N = 35) were recruited from a specialist UK centre. Participants underwent a cognitive test battery that established seven overall domain scores. The SF-36 was administered as a quality of life (QoL) measure. Controlling for age, data were compared in between-group ANCOVAs with Tukey’s post-hoc test. Any significant outcome was compared in the ECD group only, between patients who were gluten-free diet adherent vs. non-adherent (defined via Biagi score and serology results). NCD and ECD groups underperformed relative to controls, by comparable degrees, in visual (overall model: p < 0.001) and verbal (p = 0.046) memory. The ECD group only underperformed in visuoconstructive abilities (p = 0.050). Regarding QoL, the NCD group reported lower vitality (p = 0.030), while the ECD group reported more bodily pain (p = 0.009). Comparisons based on dietary adherence were non-significant. These findings confirm cognitive deficit in CD. Dysfunction appears established at the point of diagnosis, after which it (predominantly) stabilises. While a beneficial effect of dietary treatment is therefore implied, future research is needed to establish to what extent any further decline is due to gluten exposure.

Cognitive Deficit and White Matter Changes in Persons With Celiac Disease: A Population-Based Study

BACKGROUND & AIMS

There is debate over the presence and prevalence of brain injury in patients with celiac disease. To validate previous reports, we investigated the prevalence of neuropsychological dysfunction in persons with celiac disease included in the National UK Biobank, which contains experimental medical data from 500,000 adults in the United Kingdom.

METHODS

Biobank participants with celiac disease (n = 104; mean age, 63 years; 65% female) were matched with healthy individuals (controls, n = 198; mean age, 63 years; 67% female) for age, sex, level of education, body mass index, and diagnosis of hypertension. All participants were otherwise healthy. We compared scores from 5 cognitive tests and multiple choice responses to 6 questions about mental health between groups using the t test and chi-squared analyses. Groupwise analyses of magnetic resonance imaging brain data included a study of diffusion tensor imaging metrics (mean diffusivity, fractional anisotropy, radial diffusivity, axial diffusivity), voxel-based morphometry, and Mann-Whitney U comparisons of Fazekas grades.

RESULTS

Compared with control individuals, participants with celiac disease had significant deficits in reaction time (P = .004), and significantly higher proportions had indications of anxiety (P = .025), depression (P = .015), thoughts of self-harm (P = .025), and health-related unhappiness (P = .010). Tract-based spatial statistics analysis showed significantly increased axial diffusivity in widespread locations, demonstrating white matter changes in the brains of participants with celiac disease. Voxel-based morphometry and Fazekas grade analyses did not differ significantly between groups.

CONCLUSIONS

In an analysis of data from the UK Biobank, we found participants with celiac disease to have cognitive deficit, indications of worsened mental health, and white matter changes, based on analyses of brain images. These findings support the concept that celiac disease is associated with neurologic and psychological features.

Nutrition Assessment, Interventions, and Monitoring for Patients with Celiac Disease: An Evidence Analysis Center Scoping Review

The objectives of this scoping review were to identify and characterize studies examining nutrition assessment, interventions, and measures to monitor gluten-free diet (GFD) adherence/compliance in patients with celiac disease (CD). An electronic literature search of four databases (Cochrane Database for systematic reviews, CINAHL, Embase, and Ovid MEDLINE) was conducted to identify articles examining nutrition care in CD individuals. Except for narrative review, grey literature, and case study/report, all types of peer-reviewed articles published between January 2007 and August 2018 were eligible. There were a total of 10,823 records; 10,368 were excluded during the first round of screening due to irrelevancy and/or duplication. Of the 455 full-text articles that were assessed, 292 met the criteria and were included. Most of the studies were observational studies (n=212), followed by experimental trials (n=50), evidence-based practice guideline (EBPG)/report/statement (n=16), and systematic review (SR) (n=14). Nine original studies examined assessment, focusing mainly on different tools/ways to assess GFD adherence. The majority of the included original articles (n=235) were in the nutrition intervention category with GFD, oats, and prebiotics/probiotics as the top-three most studied interventions. There were eight SRs on GFD and five on oats. One SR and 21 original studies investigated the effectiveness of different measures to monitor GFD adherence/compliance. Although recent CD EBPGs were identified, different methods with varying levels of rigor, in terms of literature search and assessment of evidence strength, were used. Based on this scoping review, interventions focused on gluten-free diet and oats have been significantly covered by either SRs or EBPGs. Studies related to prebiotics/probiotics and education program/counseling focused interventions, as well as assessment, in CD patients have increased in recent years. Thus, it might be beneficial to conduct SRs/EBPGs focused on these topics to guide practitioners.

Celiac Disease: Extraintestinal Manifestations and Associated Conditions

Celiac disease is a common form of enteropathy with frequent extraintestinal manifestations (EIM). Misrecognition of these presentations may lead to significant delays in diagnosis. Any organ may be involved, either through an immune/inflammatory phenomenon, or nutritional deficiencies. Some EIM, such as gluten ataxia, may be irreversible if left untreated, but most will improve with a gluten-free diet. Knowledge of the various EIM, as well as the associated conditions which do not improve on a gluten-free diet, will avoid delays in the diagnosis and management of celiac disease and associated manifestations.

Celiac Disease Autoimmunity and Emotional and Behavioral Problems in Childhood

BACKGROUND AND OBJECTIVES

Celiac disease (CeD) is associated with psychopathology in children. It is unknown whether this association is present in children with celiac disease autoimmunity (CDA) identified by screening. We examined the associations between subclinical CDA and emotional and behavioral problems in children without previous CeD diagnosis.

METHODS

In a population-based cohort study of 3715 children (median age: 6 years), blood titers of tissue transglutaminase autoantibodies were analyzed. CDA was defined as a measurement of tissue transglutaminase autoantibodies ≥7 U/mL (n = 51). Children with previous CeD diagnosis or children on a gluten-free diet, were excluded. The Child Behavior Checklist (CBCL) was filled in by parents and was used to assess behavioral and emotional problems of children at a median age of 5.9 years. Multiple linear regression models were applied to evaluate the cross-sectional associations between CDA and CBCL scores. Sensitivity analyses were done in a subgroup of children who were seropositive carrying the HLA antigen risk alleles for CeD.

RESULTS

In basic models, CDA was not associated with emotional and behavioral problems on the CBCL scales. After adjustment for confounders, CDA was significantly associated with anxiety problems (β = .29; 95% confidence interval 0.02 to 0.55; P = .02). After exclusion of children who did not carry the HLA-DQ2 and/or HLA-DQ8 risk alleles (n = 4), CDA was additionally associated with oppositional defiant problems (β = .35; 95% confidence interval 0.02 to 0.69). Associations were not explained by gastrointestinal complaints.

CONCLUSIONS

Our results reveal that CDA, especially combined with the HLA-DQ2 and HLA-DQ8 risk alleles, is associated with anxiety problems and oppositional defiant problems. Further research should be used to establish whether behavioral problems are a reflection of subclinical CeD.

Going Against the Grains: Gluten-Free Diets in Patients Without Celiac Disease-Worthwhile or Not?

While the gluten-free diet (GFD) is the only known effective therapy for celiac disease, in recent years it has become increasingly popular in the USA and worldwide, with many believing it to be more "healthful" and others claiming that it has beneficial effects for health conditions, many extraintestinal, other than celiac disease. This review examines the evidence for use of the GFD in patients without celiac disease who self-report intestinal and/or extraintestinal symptoms (non-celiac gluten sensitivity), as well as for enhancement of athletic performance and treatment of autism, rheumatoid arthritis, and psychiatric disorders. Overall, the evidence for use of GFDs in conditions other than celiac disease is poor. Though non-celiac gluten sensitivity may ultimately emerge as a biomarker-defined condition, a large proportion of patients with apparent non-celiac gluten sensitivity have, after careful investigation, an alternative diagnosis. In light of this, and coupled with the potential physical and psychological harms associated with the avoidance of gluten, initiating a GFD should not be encouraged for people who have these other conditions or are seeking physical/athletic enhancement.

Microbiome and Cognitive Impairment: Can Any Diets Influence Learning Processes in a Positive Way?

The aim of this review is to summarize the effect of human intestinal microbiome on cognitive impairments and to focus primarily on the impact of diet and eating habits on learning processes. Better understanding of the microbiome could revolutionize the possibilities of therapy for many diseases. The authors performed a literature review of available studies on the research topic describing the influence of human microbiome and diet on cognitive impairment or learning processes found in the world's acknowledged databases Web of Science, PubMed, Springer, and Scopus. The digestive tube is populated by billions of living microorganisms including viruses, bacteria, protozoa, helminths, and microscopic fungi. In adulthood, under physiological conditions, the intestinal microbiome appears to be relatively steady. However, it is not true that it would not be influenced, both in the positive sense of the word and in the negative one. The basic pillars that maintain a steady microbiome are genetics, lifestyle, diet and eating habits, geography, and age. It is reported that the gastrointestinal tract and the brain communicate with each other through several pathways and one can speak about gut-brain axis. New evidence is published every year about the association of intestinal dysbiosis and neurological/psychiatric diseases. On the other hand, specific diets and eating habits can have a positive effect on a balanced microbiota composition and thus contribute to the enhancement of cognitive functions, which are important for any learning process.

Attention deficit and hyperactivity disorder symptoms respond to gluten-free diet in patients with coeliac disease

Introduction: Patients with coeliac disease commonly report symptoms of 'brain fog'. The aim of this study was to assess self-reported symptoms of impaired concentration in coeliac disease before and after treatment with gluten-free diet, compared with healthy controls and patient controls. Methods: Patients with newly diagnosed coeliac disease were included consecutively from two out-patient clinics. The patients completed the questionnaires Adult ADHD Self-Report Scale v1.1 Symptoms Checklist (ASRS), Hospital Anxiety and Depression Scale (HADS) and Gastrointestinal Symptom Rating Scale (GSRS) prior to start of a gluten-free diet and after at least 12 months on the diet. Patients with an established diagnosis of inflammatory bowel disease served as patient controls (n = 36). Health care personnel at Oslo University Hospital served as healthy controls (n = 60) and filled out ASRS and HADS. Results: A total of 31 newly diagnosed coeliac patients were included in the study. Of these, 26 patients met for follow-up and repeated the questionnaires. Prior to treatment, patients with coeliac disease had significantly higher scores than healthy controls on both the ASRS (p = .0014) and HADS (p=.0004). After a gluten-free diet, their scores improved and were not significantly different from healthy controls. There were no significant differences between patients with coeliac disease prior to treatment and patient controls with inflammatory bowel disease. Conclusion: Prior to treatment, coeliac disease patients reported significantly more symptoms than healthy controls on ASRS and HADS. The differences disappeared after a minimum of 12 months on a gluten-free diet.

The Celiac Disease Patients' Ability to Experience Pleasure

The motivation or ability to experience pleasure has been scarcely studied in celiac disease (CeD). We aimed to investigate the hedonistic feelings/anhedonia and sexual pleasure in CeD patients on a gluten-free diet (GFD) compared to controls. We recruited adult CeD patients at follow-up consecutively visited from April 2017 to April 2018 and controls from the hospital staff and friends of CeD patients. Participants completed the Snaith-Hamilton Pleasure Scale, measuring the levels of anhedonia, and answered three questions about physical contact, sexual activity, and modification of their life on a GFD. We included 178 CeD patients and 173 healthy controls. Seventeen patients (9.5%) and fourteen controls (8.1%) had anhedonia. We did not find any correlation between the presence of anhedonia and the length in years of GFD neither with the dietary compliance and age at the test. 10.7% patients and 8.7% controls reported of not having pleasure in physical contact and 5.06% CeD and 3.5% controls in feeling attraction for another person; 36.56% said a worsening of their life on a GFD. Our results show that CeD patients on a GFD are similar to controls in anhedonia and sexual problems, despite one-third reported a worsening of their life.

A Prospective Study on Cognitive Impairment in Middle-aged Adults With Newly Diagnosed Celiac Disease

AIMS

Our objectives were to: (1) determine whether celiac disease (CD) patients have cognitive impairment at diagnosis; and (2) compare their cognitive performance with nonceliac subjects who have similar chronic symptoms and healthy controls.

MATERIALS AND METHODS

Fifty adults (age range: 18 to 50 y) with symptoms and signs compatible with CD were enrolled in a prospective cohort irrespective of the final diagnosis. At baseline, all individuals underwent cognitive functional and psychological evaluation. CD patients were compared with subjects in whom CD was ruled out and with healthy controls matched by sex, age, and years of schooling.

RESULTS

Thirty-three subjects (66%) were diagnosed with CD. Compared with the healthy controls (n=26), CD cases and disease controls (n=17; mostly irritable bowel syndrome) had impaired cognitive performance (P=0.02 and P=0.04, respectively), functional impairment (P<0.01), and higher depression (P<0.01). CD patients had similar cognitive performance and anxiety, but nonsignificant lower depression scores compared with disease controls.

CONCLUSIONS

Abnormal cognitive functions detected in newly diagnosed CD adult patients seem not to be disease specific. Our results suggest that cognitive dysfunction could be related to the presence of prolonged symptoms due to a chronic disease.

Treatment of Neurological Manifestations of Gluten Sensitivity and Coeliac Disease

PURPOSE OF REVIEW

The aim of this paper was to overview the current literature in order to establish the available treatment options for the neurological manifestations of gluten-related disorders (serologically confirmed gluten sensitivity and coeliac disease).

RECENT FINDINGS

A range of debilitating neurological manifestations is increasingly being recognized in patients with gluten sensitivity with and without enteropathy even in the absence of gastrointestinal symptoms. Ataxia is the commonest neurological manifestation, followed by peripheral neuropathy. Epilepsy, headache, encephalopathy, various movement disorders, cognitive impairment, and muscle disorders have also been linked to gluten sensitivity and coeliac disease and are discussed in this review. Strict gluten-free diet is an effective first-line treatment of the neurological manifestations of gluten-related disorders. Very few patients will require additional immunosuppressive treatment usually in the form of mycophenolate.

Examination of Executive Function and Social Phobia Among Female College-Aged Students With Celiac Disease

Celiac disease (CD) is a T-cell mediated genetically inherited autoimmune disease affecting approximately 1% of the population. Research suggests that CD impacts executive functioning (EF) and social phobia (SP). However, most of the literature in this area focuses on age groups outside of the traditional college age range and has never measured EF and SP together. This descriptive study compared traditional age female college students with CD to age- and sex-matched college students without CD on measures of EF and SP. Participants completed the Behavior Rating Inventory of Executive Function-Adult version (BRIEF-A), the Social Anxiety Questionnaire for Adults-Short Form (SAQ-A30), and a demographic questionnaire. Results indicated that participants with CD reported lower grade point averages; scored lower on BRIEF-A measures of working memory, planning/organization, and organization of materials; and scored higher on SAQ-A30 measures involving interactions with the opposite sex and strangers. Implications for nursing practice are discussed. [Journal of Psychosocial Nursing and Mental Health Services, 57(2), 25-34.].

The Celiac Disease Patients' Ability to Experience Pleasure

The motivation or ability to experience pleasure has been scarcely studied in celiac disease (CeD). We aimed to investigate the hedonistic feelings/anhedonia and sexual pleasure in CeD patients on a gluten-free diet (GFD) compared to controls. We recruited adult CeD patients at follow-up consecutively visited from April 2017 to April 2018 and controls from the hospital staff and friends of CeD patients. Participants completed the Snaith-Hamilton Pleasure Scale, measuring the levels of anhedonia, and answered three questions about physical contact, sexual activity, and modification of their life on a GFD. We included 178 CeD patients and 173 healthy controls. Seventeen patients (9.5%) and fourteen controls (8.1%) had anhedonia. We did not find any correlation between the presence of anhedonia and the length in years of GFD neither with the dietary compliance and age at the test. 10.7% patients and 8.7% controls reported of not having pleasure in physical contact and 5.06% CeD and 3.5% controls in feeling attraction for another person; 36.56% said a worsening of their life on a GFD. Our results show that CeD patients on a GFD are similar to controls in anhedonia and sexual problems, despite one-third reported a worsening of their life.

Celiac Disease-Musculoskeletal Manifestations and Mechanisms in Children to Adults

PURPOSE OF REVIEW

We aim to review the current literature on the association of musculoskeletal disorders and celiac disease that is a common disorder, affecting about 1% of the population. Extra-intestinal symptoms and presentations predominate.

RECENT FINDINGS

While the literature supports an association with reduced bone mineral density and increased fracture risk and celiac disease, there is little evidence supporting associations with other rheumatological conditions. Patients frequently report musculoskeletal symptoms; however, studies of specific disease entities suffer from a lack of standardization of testing for celiac disease and a lack of control groups. Well-controlled, preferably population-based studies are required to further explore a relationship between celiac disease and musculoskeletal disorders.

Enriched environment on the intestinal mucosal barrier and brain-gut axis in rats with colorectal cancer

An enriched environment (EE) is an animal housing technique in which animals are given increased amounts of space, physical activity, and social interaction. Currently, researchers studying EE focus mainly on its effects within the context of neurological diseases. However, little is known about how EE affects the intestinal mucosal barrier. This study assessed the effects of EE on the intestinal mucosal barrier in rats with colorectal cancer. A rat model of 1,2-dimethylhydrazine (DMH)-induced colorectal cancer was used. The rats were housed in eight conditions for eight weeks: EE, large cages containing eight rats with stimulating objects; enlarged space and socially enriched conditions (ES), large cages containing eight rats; enlarged space and cognition enriched conditions (EC), large cages containing one rat with stimulating objects; enlarged space enriched conditions (E), large cages containing one rat; cognition and socially enriched conditions (CS), four to five rats housed in standard cages containing stimulating objects; cognition enriched conditions (C), rats housed individually in small-size cages containing stimulating objects; socially enriched conditions (S), standard cages containing four rats; and normal conditions (blank group, B). We determined the weight of each rat, measured the intestinal mucosa and plasma levels of tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), interleukin 10 (IL-10), ghrelin, corticotropin-releasing factor (CRF), occludin, bacterial translocation (BT), and secretory immunoglobulin A (SIgA), and assessed the morphology of the intestinal mucosa. On the whole, the combination of cognitive stimulus and social support was better than the combination of three factors in maintenance of the intestinal mucosal immune barrier and brain–gut peptide. The combination of all three factors and combination of cognitive training and social support were more effective than any single factor. Future studies are needed to study the effects of an EE on body weight, brain–gut peptide, and the intestinal mucosa biological barrier.

Impact statement

An enriched environment (EE) is an animal housing technique where animals are given increased amounts of space, physical activity, and social interaction. Presently, researchers studying EEs focus mainly on their effects within the context of neurological diseases. However, little is known about how EEs affect the intestinal mucosal barrier. This study assessed the effects of an EE on the intestinal mucosal barrier in rats with colorectal cancer.

Outcome measures in coeliac disease trials: the Tampere recommendations

OBJECTIVE

A gluten-free diet is the only treatment option of coeliac disease, but recently an increasing number of trials have begun to explore alternative treatment strategies. We aimed to review the literature on coeliac disease therapeutic trials and issue recommendations for outcome measures.

DESIGN

Based on a literature review of 10 062 references, we (17 researchers and 2 patient representatives from 10 countries) reviewed the use and suitability of both clinical and non-clinical outcome measures. We then made expert-based recommendations for use of these outcomes in coeliac disease trials and identified areas where research is needed.

RESULTS

We comment on the use of histology, serology, clinical outcome assessment (including patient-reported outcomes), quality of life and immunological tools including gluten immunogenic peptides for trials in coeliac disease.

CONCLUSION

Careful evaluation and reporting of outcome measures will increase transparency and comparability of coeliac disease therapeutic trials, and will benefit patients, healthcare and the pharmaceutical industry.

Cognitive Impairment and Celiac Disease: Is Transcranial Magnetic Stimulation a Trait d'Union between Gut and Brain?

Celiac disease is a systemic disorder with multifactorial pathogenesis and multifaceted symptomatology. In response to gluten exposure, a significant part of the general population produces antibodies that have been hypothesized to be deleterious to the brain. Among the well-known neurological manifestations, adult celiac patients often complain cognitive symptoms, ranging from the so-called "brain fog" till an overt dementia. Transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation technique that can contribute to the assessment and monitoring of celiac patients, even in those without a clear neurological involvement. The studies here reviewed seem to converge on an impaired central motor conductivity and a "hyperexcitable celiac brain" to TMS, which partially reverts back after a long-term gluten restriction. Notably, a clear hyperexcitability is a stably reported feature of both degenerative and vascular dementia. Therefore, given its potential neuroprotective effect, the gluten-free diet should be introduced as early as possible, although the overall response of neurological symptoms (and cognition in particular) is still controversial. Identifying new and possibly modifiable risk factors may be of crucial importance for patients, clinicians, and researchers.

Cognitive Impairment and Celiac Disease: Is Transcranial Magnetic Stimulation a Trait d'Union between Gut and Brain?

Celiac disease is a systemic disorder with multifactorial pathogenesis and multifaceted symptomatology. In response to gluten exposure, a significant part of the general population produces antibodies that have been hypothesized to be deleterious to the brain. Among the well-known neurological manifestations, adult celiac patients often complain cognitive symptoms, ranging from the so-called "brain fog" till an overt dementia. Transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation technique that can contribute to the assessment and monitoring of celiac patients, even in those without a clear neurological involvement. The studies here reviewed seem to converge on an impaired central motor conductivity and a "hyperexcitable celiac brain" to TMS, which partially reverts back after a long-term gluten restriction. Notably, a clear hyperexcitability is a stably reported feature of both degenerative and vascular dementia. Therefore, given its potential neuroprotective effect, the gluten-free diet should be introduced as early as possible, although the overall response of neurological symptoms (and cognition in particular) is still controversial. Identifying new and possibly modifiable risk factors may be of crucial importance for patients, clinicians, and researchers.

Cognitive impairment in celiac disease and non-celiac gluten sensitivity: review of literature on the main cognitive impairments, the imaging and the effect of gluten free diet

Celiac disease (CD) and non celiac gluten sensitivity (NCGS) can be responsible for neurological complications such as ataxia and peripheral neuropathies but also cognitive impairment. This cognitive involvement is variable in its expression, its duration and its prognosis ranging from transient and reversible subtle involvement to dementia itself. Through this article, we tried to achieve a review of the literature to better understand this topic. Several mechanisms were proposed to explain the deleterious influence of gluten-related pathologies on cognitive functions: nutritional deficiencies, elevation of circulating cytokine levels due to systemic inflammation, low brain serotonin levels… Several types of dementia such as Alzheimer dementia, vascular dementia, frontotemporal dementia were reported in association with CD. Memory disorder, acalculia, inattention, visuospatial deficits and executive dysfunction must be sought systematically by a neuropsychological assessment in patients with CD or NCGS. As far as the cognitive impairment is concerned, there is no pathognomonic radiological lesion. Concerning therapeutic management; although its effect is controversial, gluten free diet should be introduced, as early as possible, because of its potentially protective effect.

Effect of childhood coeliac disease on ninth grade school performance: evidence from a population-based study

BACKGROUND

Coeliac disease might affect school performance due to its effect on cognitive performance and related health consequences that might increase school absenteeism. The aim of this study was to investigate whether children with coeliac disease performed differently on completion of ninth grade in school compared with children without coeliac disease.

METHODS

Analysis was performed on a population of 445 669 children born in Sweden between 1991 and 1994 of whom 1767 were diagnosed with coeliac disease. School performance at ninth grade was the outcome and coeliac disease was the exposure. Other covariates included sex, Apgar score at 5 min, small for gestational age, year of birth, family type, parental education and income.

RESULTS

There was no association between coeliac disease and school performance at ninth grade (adjusted coefficient -2.4, 95% CI 5.1 to 0.4). A weak association was established between late coeliac diagnosis and higher grades, but this disappeared after adjusting for parent socioeconomic conditions. Being small for gestational age affected performance negatively (adjusted coefficient -6.9, 95% CI 8.0 to 5.7). Grade scores were significantly lower in children living with a single parent (adjusted coefficient -20.6, 95% CI 20.9 to 20.2), compared with those with married/cohabiting parents. A positive association was found between scores at ninth grade and parental education and income.

CONCLUSION

Coeliac disease diagnosis during childhood is not associated with poor school performance at ninth grade.

Younger age at diagnosis predisposes to mucosal recovery in celiac disease on a gluten-free diet: A meta-analysis

Background and aims

Persistent intestinal damage is associated with higher complication rates in celiac disease. We aimed to assess the potential modifiers of mucosal recovery.

Materials and methods

We screened databases (PubMed, Embase, Cochrane Trials, and Web of Science) for papers on celiac disease. Papers discussing (1) celiac patients (2) follow-up biopsy and (3) mucosal recovery after commencement of a gluten-free diet were included. The primary outcome was to produce a comprehensive analysis of complete mucosal recovery (i.e., Marsh 0 on follow-up). We compared children’s recovery ratios to those of adults. Patients following a strict gluten-free dietary regimen were included in a subgroup. Summary point estimates, 95% confidence intervals (CIs), and 95% predictive intervals (PIs) were calculated. Heterogeneity was tested with I²-statistic. The PROSPERO registration number is CRD42016053482.

Results

The overall complete mucosal recovery ratio, calculated from 37 observational studies, was 0.36 (CI: 0.28–0.44, PI: -0.12–0.84; I²: 98.4%, p<0.01). Children showed higher complete mucosal recovery ratio than adults (p<0.01): 0.65 (CI: 0.44–0.85, PI: -0.10–1.39; I²: 96.5%, p<0.01) as opposed to 0.24 (CI: 0.15–0.33, PI: -0.19–1.08; I²: 96.3%, p<0.01). In the strict dietary adherence subgroup, complete mucosal recovery ratio was 0.47 (CI: 0.24–0.70, PI: -0.47–1.41; I²: 98.8%, p<0.001). On meta-regression, diagnostic villous atrophy (Marsh 3) ratio (-8.97, p<0.01) and male ratio (+6.04, p<0.01) proved to be a significant determinant of complete mucosal recovery, unlike duration of gluten-free diet (+0.01, p = 0.62). The correlation between complete mucosal recovery ratio and age on diagnosis is of borderline significance (-0.03, p = 0.05).

Conclusions

There is considerable heterogeneity across studies concerning complete mucosal recovery ratios achieved by a gluten-free diet in celiac disease. Several celiac patients fail to achieve complete mucosal recovery even if a strict dietary regimen is followed. Younger age on diagnosis, less severe initial histologic damage and male gender predispose for achieving mucosal recovery.

Neurophysiology of the "Celiac Brain": Disentangling Gut-Brain Connections

Celiac disease (CD) can be considered a complex multi-organ disorder with highly variable extra-intestinal, including neurological, involvement. Cerebellar ataxia, peripheral neuropathy, seizures, headache, cognitive impairment, and neuropsychiatric diseases are complications frequently reported. These manifestations may be present at the onset of the typical disease or become clinically evident during its course. However, CD subjects with subclinical neurological involvement have also been described, as well as patients with clear central and/or peripheral nervous system and intestinal histopathological disease features in the absence of typical CD manifestations. Based on these considerations, a sensitive and specific diagnostic method that is able to detect early disease process, progression, and complications is desirable. In this context, neurophysiological techniques play a crucial role in the non-invasive assessment of central nervous system (CNS) excitability and conductivity. Moreover, some of these tools are known for their valuable role in early diagnosis and follow-up of several neurological diseases or systemic disorders, such as CD with nervous system involvement, even at the subclinical level. This review provides an up-to-date summary of the neurophysiological basis of CD using electroencephalography (EEG), multimodal evoked potentials, and transcranial magnetic stimulation (TMS). The evidence examined here seems to converge on an overall profile of "hyperexcitable celiac brain," which partially recovers after institution of a gluten-free diet (GFD). The main translational correlate is that in case of subclinical neurological involvement or overt unexplained symptoms, neurophysiology could contribute to the diagnosis, assessment, and monitoring of a potentially underlying CD.