Words fail me: the verbal IQ deficit in inflammatory bowel disease and irritable bowel syndrome

The impact of cognitive functions, psychological disorders, and coping strategies on quality of life and disease outcomes in patients with inflammatory bowel diseases: A cross-sectional study

Quality of life (QoL) in patients with inflammatory bowel disease (IBD) is influenced by several factors, many of which may also impact cognitive function. However, the extent of the interaction among these factors, QoL, and disease outcomes in IBD patients remains unknown. We thus aim to characterize the relationships among psychological disorders, coping mechanisms, cognitive function, and the overall impact on QoL and disease outcomes in patients with IBD. This cross-sectional observational study was conducted at an academic care center. QoL was evaluated using the Short Inflammatory Bowel Disease Questionnaire (SIBDQ), and disease severity was evaluated using the Harvey-Bradshaw Index (HBI) for Crohn's disease (CD) and the Simple Clinical Colitis Activity Index (SCCAI) for ulcerative colitis (UC). We also used the Hospital Anxiety and Depression scale (HADS). Regression models were used to test the associations among QoL, number of hospitalizations, disease severity, cognitive functioning (working memory [WM] and reaction time), and coping strategies while controlling for anxiety and depressive symptoms, age, and sex. This study included 41 patients (24 patients with CD and 17 with UC) whose mean age was 28.2 (±8.4) years (23 males) and mean SIBDQ score was 51.5 (±10.0). Patients with more WM errors had lower QoL scores (P = .041), whereas patients with higher anxiety levels had lower QoL and more active UC (P = .008 and P = .016, respectively). The use of avoidant coping mechanisms was associated with a significantly higher number of hospitalizations (P = .038), and patients who adopted more emotion-focused coping strategies had a longer illness duration (P = .021). Finally, patients with higher education levels were found to use more active coping mechanisms than others. These results confirm the impact of cognitive, psychological, and coping factors on QoL and disease outcomes in patients with IBD; however, the mechanisms by which these factors interrelate remain unclear. Therapies aimed at improving both cognitive functions and psychological conditions may thus be effective at improving QoL and disease outcomes in IBD patients, and education may play a positive role in promoting the adoption of more effective coping strategies among IBD patients.

Vascular comorbidity is associated with decreased cognitive functioning in inflammatory bowel disease

Reports of cognitive impairment in inflammatory bowel disease (IBD) have been mixed. IBD and cardiovascular disease are often co-morbid, yet it remains unknown whether vascular comorbidity confers a risk for decreased cognitive functioning, as observed in other populations. Participants with IBD were recruited from a longitudinal study of immune-mediated disease. Participants were administered a standardized neuropsychological test protocol, evaluating information processing speed, verbal learning and memory, visual learning and memory, and verbal fluency/executive function. Cognitive test scores were standardized using local regression-based norms, adjusting for age, sex, and education. Vascular risk was calculated using a modified Framingham Risk Score (FRS). We tested the association between FRS and cognitive test scores using a quantile regression model, adjusting for IBD type. Of 84 IBD participants, 54 had ulcerative colitis and 30 had Crohn's disease; mean (SD) age was 53.36 (13.95) years, and a high proportion were females (n = 58). As the risk score (FRS) increased, participants demonstrated lower performance in information processing speed (β = - 0.12; 95% CI - 0.24, - 0.006) and verbal learning (β = - 0.14; 95% CI - 0.28, - 0.01) at the 50^th percentile. After adjusting for IBD type and disease activity, higher FRS remained associated with lower information processing speed (β = - 0.14; 95% CI - 0.27, - 0.065). Vascular comorbidity is associated with lower cognitive functioning in persons with IBD, particularly in the area of information processing speed. These findings suggest that prevention, identification, and treatment of vascular comorbidity in IBD may play a critical role for improving functional outcomes in IBD.

Inflammatory bowel disease-associated Escherichia coli strain LF82 in the damage of gut and cognition of honeybees

Patients with inflammatory bowel disease (IBD) are often accompanied with some cognitive impairment, but the mechanism is unclear. By orally exposing honeybees (Apis mellifera) to IBD-associated Escherichia coli LF82 (LF82), and non-pathogenic Escherichia coli MG1655 (MG1655) as the normal strain, we investigated whether and how LF82 induces enteritis-like manifestations and cognitive behavioral modifications in honeybees using multiparametric analysis. LF82 significantly increased gut permeability, impaired learning and memory ability in olfactory proboscis extension response conditioning, and shortened the lifespan of honeybees. Compared to MG1655, LF82 reduced the levels of tryptophan metabolism pathway substances in the honeybee gut. LF82 also upregulated genes involved in immune and apoptosis-related pathways and downregulated genes involved in G protein-coupled receptors in the honeybee brain. In conclusion, LF82 can induce enteritis-like manifestations and cognition impairment through gut metabolites and brain transcriptome alteration in honeybees. Honeybees can serve as a novel potential model to study the microbiota-gut-brain interaction in IBD condition.

Altered Intra- and Inter-Network Functional Connectivity in Patients With Crohn’s Disease: An Independent Component Analysis-Based Resting-State Functional Magnetic Resonance Imaging Study

Background

Many studies have reported changes in the structure and function of several brain areas in patients with Crohn’s disease (CD). However, little is known about whether the possible functional connectivity of resting-state networks (RSNs) is altered in CD patients.

Purpose

Aim to investigate the intra- and inter-network alterations between related RSNs in patients with CD and the potential relationships between altered neuroimaging and CD clinical indices.

Materials and Methods

In this study, 20 CD patients and 22 age- and sex-matched healthy controls were included. All participants underwent functional magnetic resonance imaging examination. We used independent component analysis (ICA) to explore the changes in RSNs and evaluated functional connectivity between different RSNs using functional network connectivity (FNC) analysis, and Pearson correlation analysis was performed between altered intra- and inter-network functional connectivity and CD clinical index.

Results

Six CD-related RSNs were identified via ICA, namely the high visual, prime visual, language, dorsal default mode, posterior insula, and precuneus networks. Compared to healthy controls, patients with CD showed significant changes in prime visual and language networks. Additionally, the functional connectivity (FC) values of the left calcarine within the prime visual network were negatively correlated with CD duration. The inter-alterations showed that a significantly increased FNC existed between the language and dorsal default mode networks.

Conclusion

The results showed CD-related changes in brain functional networks. This evidence provides more insights into the pathophysiological mechanisms of brain plasticity in CD.

Functional abdominal pain symptom severity: Associations between cognition and emotion in a pediatric sample

Functional abdominal pain (FAP) is a common physical complaint in children and adolescents. Prior research has documented associations between FAP symptoms and mood, especially internalizing behaviors. Limited research is available examining the association between symptom burden and cognitive function in this pediatric population. This study explored associations between FAP symptoms, internalizing behaviors, and cognitive and school function in children and adolescents. Twenty-seven participants (mean age = 12.6 years, range 8.8-16.5; 33% male) diagnosed with FAP completed assessments of cognitive, emotional, and behavioral function, as well as FAP symptom severity. Mean performances on cognitive tests were within age-expected ranges. Within this context, however, higher overall burden of FAP symptoms was associated with slower processing speed, more self-reported metacognitive problems and internalizing behaviors, and more school absences. Cognitive function was systematically associated with internalizing behaviors but not physical symptoms. Overall, findings revealed that FAP may be associated with cognitive inefficiencies in addition to internalizing problems. Cognitive symptoms may be linked to internalizing behaviors associated with FAP.

Brain functional changes in patients with Crohn's disease: A resting-state fMRI study

BACKGROUND

Crohn's disease (CD) is a chronic recurrent intestinal inflammatory disease, often accompanied by poor adaptation and excessive stress response. However, the potential neurological mechanisms of these symptoms have not yet been studied in-depth.

OBJECTIVE

To investigate alterations in brain activity in patients with Crohn's disease and study the relationship between altered regions and clinical indices.

METHODS

A total of 15 CD patients and 26 matched healthy controls were recruited. All participants underwent fMRI scans. The amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) assessed differences in spontaneous regional brain activity. Differences between the groups were selected as seeds for functional connectivity (FC) analyses. Correlations between disease duration and ALFF/ReHo/FC values in abnormal regions were analyzed.

RESULTS

Patients with CD had significantly higher ALFF values in the left superior frontal gyrus, anterior cingulate cortex, and supplementary motor area, and lower values in the left hippocampus. They also had higher ReHo values in the left anterior cingulate cortex, supplementary motor area, putamen, and the bilateral superior frontal gyri. FC strength in the left precentral and middle temporal gyri was found to be increased when the left superior frontal gyrus was used as the seed point. FC strength was also observed to be increased in the left postcentral, middle frontal gyri, inferior frontal orbital cortex, and right rolandic operculum when the left anterior cingulate cortex was used as the seed point.

CONCLUSION

CD demonstrated abnormal neural activity and FC in various regions primarily associated with emotional, pain and cognitive-related functions, which provides more information to further understand the neural mechanisms of the disease.

Cognitive dysfunction in ulcerative colitis patients in remission and its comparison with patients with irritable bowel syndrome and healthy controls

BACKGROUND

There is a paucity of research concerning cognitive impairments in Inflammatory bowel disease - ulcerative colitis (IBD-UC) and irritable bowel syndrome (IBS). Studies on cognitive dysfunction in patients with IBD-UC have either been small or have shown conflicting results. This study is conducted to examine the evidence of cognitive dysfunction in IBD-UC patients in remission and compare the evident cognitive deficit with IBS patients and healthy controls.

METHODS

This single-centre cross-sectional observational study enrolled a total of 90 participants, 29 in ulcerative colitis (UC) in remission group, 31 in IBS group and 30 in healthy control group. Assessment of cognition with the help of cognitive function tests mini-mental state examination (MMSE), Montreal Cognitive Assessment (MoCA) test and p300 was performed in all participants.

RESULTS

A statistically significant number of the participants in IBD-UC in remission group had MMSE and MoCA score below the lower limit of normal, in comparison to the healthy control and IBS groups. The mean peak latency of the p300 wave was statistically significantly increased in people in the IBD-UC group, in comparison to the healthy control and IBS groups.

CONCLUSION

Patients with IBD-UC in remission show impairments in cognitive functioning compared to the IBS and healthy control groups as assessed on cognitive function testing on MMSE, MoCA and mean peak latency of the p300 wave. This impairment in cognitive function is unlikely to be due to premorbid levels of intellectual functioning and is likely to have impact on health-related quality of life.

Gut Inflammation Induced by Dextran Sulfate Sodium Exacerbates Amyloid-β Plaque Deposition in the AppNL-G-F Mouse Model of Alzheimer's Disease

BACKGROUND

Although it is known that the brain communicates with the gastrointestinal (GI) tract via the well-established gut-brain axis, the influence exerted by chronic intestinal inflammation on brain changes in Alzheimer's disease (AD) is not fully understood. We hypothesized that increased gut inflammation would alter brain pathology of a mouse model of AD.

OBJECTIVE

Determine whether colitis exacerbates AD-related brain changes.

METHODS

To test this idea, 2% dextran sulfate sodium (DSS) was dissolved in the drinking water and fed ad libitum to male C57BL/6 wild type and AppNL-G-F mice at 6-10 months of age for two cycles of three days each. DSS is a negatively charged sulfated polysaccharide which results in bloody diarrhea and weight loss, changes similar to human inflammatory bowel disease (IBD).

RESULTS

Both wild type and AppNL-G-F mice developed an IBD-like condition. Brain histologic and biochemical assessments demonstrated increased insoluble Aβ1-40/42 levels along with the decreased microglial CD68 immunoreactivity in DSS treated AppNL-G-F mice compared to vehicle treated AppNL-G-F mice.

CONCLUSION

These data demonstrate that intestinal dysfunction is capable of altering plaque deposition and glial immunoreactivity in the brain. This study increases our knowledge of the impact of peripheral inflammation on Aβ deposition via an IBD-like model system.

Impaired cognitive function in Crohn's disease: Relationship to disease activity

Background & aims

Impaired attention and response inhibition have been reported in patients with Crohn’s disease (CD) in clinical remission. Prospective studies are needed to determine whether this is a stable feature of CD and whether a similar impairment is evident in ulcerative colitis (UC). Thus, our aims were to examine whether patients with CD and UC exhibited a persistent impairment in attentional performance, and if this impairment was related to key biological indices of relevance to cognition.

Methods

A prospective observational study was conducted on fifteen patients with CD and 7 with UC in clinical remission recruited from a specialty clinic and 30 healthy matched control participants. A neuropsychological assessment was carried out at baseline (visit 1) and at a 6 month follow-up (visit 2). Plasma proinflammatory cytokines, the plasma kynurenine:tryptophan (Kyn:Trp) ratio and the salivary cortisol awakening response (CAR) were also determined at each visit.

Results

Across visits, patients with CD exhibited impaired attentional performance (p ​= 0.023). Plasma IL-6 (P ​= ​0.001) and the Kyn:Trp ratio (P ​= ​0.03) were consistently elevated and the CAR significantly blunted (P ​< ​0.05) in patients with CD. No significant relationships were identified between any biochemical parameter and altered cognitive performance.

Conclusions

Impaired cognitive function is a stable feature of patients with CD. These data suggest that even where remission has been achieved, the functional impact of an organic gastrointestinal disorder on cognition is still evident. However, it is unclear at present if physiological changes due to disease activity play a role in cognitive impairment in CD.

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Crohn’s disease (CD) patients previously associated with impaired cognition.

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CD patients consistently exhibited impaired attentional performance at multiple visits.

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Functional impact of organic gastrointestinal disorder on cognition still evident in remission.

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Increased IL-6, kynurenine pathway activation and blunted cortisol awakening response in CD.

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Biochemical parameters not associated with altered cognitive performance.

Impaired neurocognitive and psychomotor performance in patients with inflammatory bowel disease

Limited evidence exists regarding cognitive and psychomotor function in patients with inflammatory bowel disease (IBD). Therefore, we aimed to compare the neurocognitive and psychomotor function of 60 IBD patients with 60 age/sex-matched controls. Computer-based instrument Complex Reactinometer Drenovac (CRD) was used for assessment of cognitive domains: convergent thinking (simple mathematical tasks; CRD-11), perceptive abilities (light signal position discrimination; CRD-311) and sophisticated operative thinking (complex psychomotor coordination; CRD-411). The most important analyzed parameters were total test solving time (T_TTS); minimal time of particular test solving (T_MIN) and total number of wrong reactions (N_ER). Performance in all three cognitive tests showed statistically significantly longer T_TTS and T_MIN in IBD patients (P < 0.05), while there was no significant difference in N_ER. Aforementioned findings were adjusted for BMI, age and duration of education. Our study has shown impaired neurocognitive and psychomotor function in IBD patients compared to controls, especially in mental processing speed and mental endurance of perceptive abilities, convergent thinking and complex operative thinking.

Impaired neurocognitive and psychomotor performance in patients with inflammatory bowel disease

Limited evidence exists regarding cognitive and psychomotor function in patients with inflammatory bowel disease (IBD). Therefore, we aimed to compare the neurocognitive and psychomotor function of 60 IBD patients with 60 age/sex-matched controls. Computer-based instrument Complex Reactinometer Drenovac (CRD) was used for assessment of cognitive domains: convergent thinking (simple mathematical tasks; CRD-11), perceptive abilities (light signal position discrimination; CRD-311) and sophisticated operative thinking (complex psychomotor coordination; CRD-411). The most important analyzed parameters were total test solving time (T_TTS); minimal time of particular test solving (T_MIN) and total number of wrong reactions (N_ER). Performance in all three cognitive tests showed statistically significantly longer T_TTS and T_MIN in IBD patients (P < 0.05), while there was no significant difference in N_ER. Aforementioned findings were adjusted for BMI, age and duration of education. Our study has shown impaired neurocognitive and psychomotor function in IBD patients compared to controls, especially in mental processing speed and mental endurance of perceptive abilities, convergent thinking and complex operative thinking.

Cognitive impairment in Irritable Bowel Syndrome (IBS): A systematic review

BACKGROUND

Irritable Bowel Syndrome (IBS) is a common functional gastrointestinal disorder which is characterized by altered bowel habits. A growing number of studies investigate the association between IBS and cognitive impairments. Current studies report conflicting results regarding cognitive impairment in IBS patients. We therefore conducted the first systematic review to examine the association between IBS and cognitive impairment and identify the types of cognitive domain involved.

STUDY DESIGN

Eight databases (MEDLINE, CINAHL, EMBASE, Cochrane Library, PsycINFO, ScienceDirect, China National Knowledge Infrastructure (CNKI), and Chinese Biomedical Literature Database (CBM)) were searched from the inception date up till 15 February 2018. Observational studies published in English or Chinese were independently appraised, and data was extracted, by two reviewers using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Analytical Cross-Sectional Studies. The findings were synthesized using a narrative approach.

RESULTS

Twelve studies met the inclusion criteria. Our findings suggested that IBS patients exhibited attentional bias towards GI sensation words and emotionally negative words. There was insufficient evidence of evidences to show that IBS patients had cognitive deficits in memory, intelligence, executive functions and general cognitive functions. A number of limitations were identified, including small sample, limited cognitive domain inclusion, lack of study details, and management of confounding variables.

CONCLUSION

There is evidence of attentional bias in individuals with IBS; the evidence on cognitive impairment was either inconclusive or insufficient in other cognitive domains. Further studies are needed to confirm prevalence rates and examine potential mechanisms.

Aberrant brain structural large-scale connectome in Crohn's disease

BACKGROUND

Disturbed brain-gut interactions and a bidirectional relationship between inflammation and psychiatric symptoms such as anxiety and depression are being discussed in patients with inflammatory bowel diseases (IBD). Alterations of brain structure and function in IBD have been reported with heterogeneous results. Whether these changes reflect independent localized deficits or rather a systematic disruption in the anatomical organization of large-scale brain networks remains unclear. The present study investigated the gray matter structural connectome in patients with Crohn's disease (CD).

METHODS

Sixty participants (30 with quiescent CD and 30 matched healthy controls [HC]) underwent high-resolution brain MRI at 3 Tesla. Well-established graph theoretical metrics were analyzed at the global and regional network level and compared between groups.

KEY RESULTS

The networks in both groups followed a small-world organization, that is, an architecture that is simultaneously highly segregated and integrated. However, transitivity, a measure of global network segregation, was significantly reduced in patients (P = 0.003). Regionally, patients showed a reduction of nodal betweenness centrality in the right insula and cuneus and the left superior frontal cortex and reduced nodal degree within the left-hemispheric cingulate and the left lateral and right medial orbitofrontal cortex.

CONCLUSION AND INFERENCES

These findings lend support to the hypothesis that CD is accompanied by alterations in both global network organization and regional connectivity. A deeper understanding of neural central networks in IBD may facilitate the development of complementary strategies in the treatment of "extraintestinal" comorbid conditions such as depression or anxiety.

A Verbal Fluency Task-Based Brain Activation fMRI Study in Patients with Crohn's Disease in Remission

BACKGROUND AND PURPOSE

In this pilot study, we investigated functional brain activation changes in patients with Crohn's disease (CD) in remission compared to age and gender-matched healthy controls (HCs).

METHODS

Data from 20 patients with CD in remission (age range 19-63 years) and 20 HCs (matched in age and gender) were analyzed. Task functional MRI (fMRI) data were collected while participants performed a cognitive (phonemic verbal fluency) task in the scanner. All participants also performed the same task outside the scanner.

RESULTS

Task fMRI results showed greater bi-hemispheric activation in CD patients compared to controls. Because this pattern is commonly reported with normal aging, we performed further analyses to investigate fMRI responses in a subset of the younger CD patients (N = 12, age < = 35 years) compared to matched young HCs (age < = 35 years), and an older cohort of HCs (age > = 50 years). Results showed that task activation patterns were similar between young CD patients and older HCs, and that both groups differed significantly from younger HCs. Activation intensity in specific brain regions for patients was associated with disease duration.

CONCLUSIONS

These results suggest that CD patients in remission may show accelerated signs of aging in terms of brain responses to a typical cognitive task. Future work with larger sample size will need to replicate these results as well as investigate the influence of factors, such as chronicity of the disease and medication effects on task-associated brain activation patterns in this patient population.

Increased risk of chronic fatigue syndrome in patients with inflammatory bowel disease: a population-based retrospective cohort study

Background

Similarities in the symptoms of chronic fatigue syndrome (CFS) and inflammatory bowel disease (IBD) have been observed as follows: severe disease activity in IBD correlates with severe fatigue, major psychiatric signs, the common use of medication, and bacterial translocation. One of several hypotheses for explaining the mechanisms underlying CFS suggests a similarity to the impaired intestinal mucosa of IBD. “This study investigated the risk of incident CFS among patients with IBD”.

Methods

We conducted a population-based retrospective cohort study by using Taiwan’s National Health Insurance Research Database to evaluate the subsequent risk of CFS in patients with IBD, according to demographic characteristics and comorbidities. The exposure cohort comprised 2163 patients with new diagnoses of IBD. Each patient was randomly selected and frequency matching according to gender and age with four participants from the general population who had no history of CFS at the index date (control cohort). Cox proportional hazards regression analysis was conducted to estimate the relationship between IBD and the subsequent risk of CFS.

Results

The exposure cohort had a significantly higher overall risk of subsequent CFS than that of the control group [adjusted hazard ratio (Christophi in Inflamm Bowel Dis 18(12):2342–2356, 2012) = 2.25, 95%, confidence interval (Aaron and Buchwald in Ann Intern Med 134(9 Pt 2):868–881, 2001; Farraye et al. in Am J Gastroenterol 112:241, 2017) 1.70–2.99]. Further analysis indicated a significantly higher risk of CFS in patients who were male (HR = 3.23, 95% CI 2.12–4.91), were older than 35 years, and had IBD but without comorbidity status, e.g. Cancers, diabetes, obesity, depression, anxiety, sleep disorder, renal disease (HR = 2.50, 95% CI 1.63–3.84) after adjustment.

Conclusion

The findings from this population-based retrospective cohort study suggest that IBD, especially Crohn’s disease, is associated with an increased risk of subsequent CFS.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1797-3) contains supplementary material, which is available to authorized users.

Comparison of comorbid depression between irritable bowel syndrome and inflammatory bowel disease: A meta-analysis of comparative studies

BACKGROUND

The prevalence of comorbid depression is high in chronic gastrointestinal disorders, including irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). For these two disorders in particular, the findings have not been consistent. This meta-analysis systematically compares the rates and severity of comorbid depression between IBS and IBD patients.

METHODS

A systematic literature search was conducted using PubMed, PsycINFO, Embase, Cochrane Library, Wan Fang, SinoMed, Chinese National Knowledge Infrastructure from their inception date to September 12, 2017 for comparative studies on IBS and IBD patients. Standardized mean differences (SMDs) and odds ratios (OR) of comorbid depression were calculated using random effect models. Data on comorbid anxiety in the included studies were also extracted and analyzed.

RESULTS

Altogether, 22 studies with 1,244 IBS and 1,048 IBD patients were included. While there was no significant group difference in the prevalence of depression (10 studies, OR = 1.18, 95%CI: 0.87-1.60, P = 0.29), the IBS group had more severe depression (pooled SMD = 0.18, 95%CI: 0.04-0.33, P = 0.01) and anxiety than the IBD group (pooled SMD = 0.31, 95%CI: 0.14-0.49, P = 0.0006). Sixteen (72.7%) studies were assessed as 'high quality' using the Newcastle-Ottawa Scale (NOS).

CONCLUSIONS

Although the prevalence of comorbid depression was similar between groups, IBS patients had more severe comorbid depressive and anxiety symptoms compared to IBD patients. Appropriate assessment and treatment of depressive and anxiety symptoms in these patient groups should be implemented.

Specific neurophysiological mechanisms underlie cognitive inflexibility in inflammatory bowel disease

Inflammatory bowel disease (IBD) is highly prevalent. While the pathophysiological mechanisms of IBD are increasingly understood, there is a lack of knowledge concerning cognitive dysfunctions in IBD. This is all the more the case concerning the underlying neurophysiological mechanisms. In the current study we focus on possible dysfunctions of cognitive flexibility (task switching) processes in IBD patients using a system neurophysiological approach combining event-related potential (ERP) recordings with source localization analyses. We show that there are task switching deficits (i.e. increased switch costs) in IBD patients. The neurophysiological data show that even though the pathophysiology of IBD is diverse and wide-spread, only specific cognitive subprocesses are altered: There was a selective dysfunction at the response selection level (N2 ERP) associated with functional alterations in the anterior cingulate cortex and the right inferior frontal gyrus. Attentional selection processes (N1 ERP), perceptual categorization processes (P1 ERP), or mechanisms related to the flexible implementation of task sets and related working memory processes (P3 ERP) do not contribute to cognitive inflexibility in IBD patients and were unchanged. It seems that pathophysiological processes in IBD strongly compromise cognitive-neurophysiological subprocesses related to fronto-striatal networks. These circuits may become overstrained in IBD when cognitive flexibility is required.

Intrinsic neural network dysfunction in quiescent Crohn's Disease

Psychological factors and comorbidities play an important role in inflammatory bowel diseases. Such comorbidity could be associated with a specific neural phenotype. Brain regions associated with emotion regulation and self-referential processing, including areas assigned to the “default mode network” (DMN), could be promising candidates in this regard. We investigated the functional integrity of multiple intrinsic neural networks in remitted patients with Crohn’s disease (CD) and sought to establish relationships between neural network connectivity and psychiatric symptoms. Fifteen CD patients in remission and 14 controls were investigated. We employed resting-state functional magnetic resonance imaging (fMRI) at 3 Tesla followed by a spatial Independent Component Analysis for fMRI data. Abnormal connectivity in CD patients was observed in DMN subsystems only (p < 0.05, cluster-corrected). Increased connectivity was found in the anterior cingulate and left superior medial frontal gyrus (aDMN) and the middle cingulate cortex (pDMN). Middle cingulate activity showed a significant association with anxiety scores in patients (p = 0.029). This study provides first evidence of selectively disrupted intrinsic neural network connectivity in CD and suggests abnormalities of self-referential neural networks. An increased sensitivity to self-related affective and somatic states in CD patients could account for these findings and explain a higher risk for anxiety symptoms.

The Increased Level of Depression and Anxiety in Irritable Bowel Syndrome Patients Compared with Healthy Controls: Systematic Review and Meta-analysis

BACKGROUND/AIMS

Irritable bowel syndrome (IBS) patients commonly experience psychiatric disorders, such as depression and anxiety. This meta-analysis sought to compare depression and anxiety levels between IBS patients and healthy controls.

METHODS

We searched major electronic databases (PubMed, EMBASE, MEDLINE, and Cochrane library) to find comparative studies on IBS patients and healthy controls. The primary outcome was a standardized mean difference (SMD) of anxiety and depression levels; sub-group analyses were conducted according to IBS-subtypes.

RESULTS

In total, 2293 IBS patients and 4951 healthy controls from 27 studies were included. In random effect analysis, depression and anxiety levels were significantly higher in IBS patients (pooled SMD = 0.76; 95% CI, 0.62-0.90; P < 0.001; I2 = 77.2% and pooled SMD = 0.84; 95% CI, 0.67-1.01; P < 0.001; I2 = 85.6%, respectively). Both analyses' funnel plots showed symmetry. In meta-regression analysis, heterogeneity was due to the studied region and questionnaire type for both depression and anxiety. In sub-group analyses of IBS-subtype, the pooled SMDs of depression and anxiety levels (IBS with predominant constipation: 0.83 and 0.81, IBS with predominant diarrhea: 0.73 and 0.65, and IBS with mixed bowel habits: 0.62 and 0.75; P < 0.001, respectively) were significantly higher in all IBS-subtypes.

CONCLUSIONS

The present meta-analysis showed depression and anxiety levels to be higher in IBS patients than in healthy controls, regardless of IBS-subtype. However, the gender effect on psychological factors among IBS patients could not be determined and should be evaluated in prospective studies.

Attention and memory impairments in pediatric patients with cystic fibrosis and inflammatory bowel disease in comparison to healthy controls

The main aim of the study was to analyze and compare attention and memory performance in pediatric patients with cystic fibrosis (CF), inflammatory bowel disease (IBD) and in healthy controls. 28 patients with CF, 30 patients with IBD and 30 healthy subjects took part in the study (all in age range of 7–17). All subjects were in intellectual norm. To analyze the functioning of attention, the d2 Test of Attention by Brickenkamp (d2 test) was applied. Memory performance was assessed using the Benton Visual Retention Test (BVRT) and the Trial of 10 words. The CF and IBD groups committed significantly more errors in the d2 test than the healthy controls. The CF group also had significantly higher fluctuation rates and received significantly lower scores in overall concentration performance than the control group. Patients with CF made more mistakes and had fewer correct memory projections in BVRT than the healthy controls. Patients with IBD committed significantly more errors in BVRT than the control group. Patients with CF and IBD also got significantly lower scores in the Trial of 10 words than the control group. Pediatric patients with CF and IBD performed more poorly than the healthy controls on attention and memory tests. More distinct cognitive impairments were observed in the CF group. Further research is needed to find the underlying mechanisms and clinical and/or functional significance of observed cognitive deficits.

Cognitive impairment in Crohn's disease is associated with systemic inflammation, symptom burden and sleep disturbance

BACKGROUND

Patients with Crohn's disease (CD) frequently complain of cognitive difficulties such as problems with concentration and clouding of thought, yet this has scarcely been objectively defined and underlying mechanisms remain unknown.

OBJECTIVE

The objective of this article is to objectively measure cognitive impairments in patients with CD compared with healthy controls, and if present, to identify potentially modifiable, contributing factors associated with cognitive impairment.

METHODS

CD patients and healthy age-/sex-matched controls completed surveys encompassing clinical, demographic, psychiatric, fatigue and sleep parameters. Contemporaneously, disease activity assessment with serum CRP, faecal calprotectin, Harvey-Bradshaw Index and the Subtle Cognitive Impairment test (SCIT) were performed, with the primary measure of response time (SCIT-RT) compared between groups. Multiple linear regression assessed for factors associated with slower SCIT-RT, denoting subtle cognitive impairment.

RESULTS

A total of 49 CD and 31 control individuals participated, with median age 44 years (range 22-65) and 43 years (21-63), respectively. Compared to controls, SCIT-RT was slower across all timepoints in CD patients (ANOVA p < 0.001). In multivariate analysis, serum CRP (standardised beta coefficient 0.27, 95% CI (0.02, 0.51)), abdominal pain (0.43 (0.16, 0.70)), plasma haemoglobin (1.55 (1.42, 1.68)), and concurrent fatigue (0.56 (0.25, 0.88)) were each independently associated with slower SCIT-RT in CD (each p < 0.05), with a trend for poorer sleep quality 0.54 (-0.03, 1.11) (p = 0.06), yet conversely, higher faecal calprotectin titres were associated with faster SCIT-RT (-1.77 (-1.79, -1.76), p < 0.01).

CONCLUSIONS

Patients with CD demonstrated subtle cognitive impairment utilising the objective SCIT, correlating with systemic inflammation and other disease burden measures, although higher faecal calprotectin titres were unexpectedly associated with less cognitive impairment.

Cognitive Function of Patients with Crohn's Disease is Associated with Intestinal Disease Activity

BACKGROUND

Systemic inflammation and nutritional deficiencies are characteristics of Crohn's disease (CD) and have been suggested to influence cognitive performance. This study assessed cognitive function in patients with CD.

METHODS

Participants were adult patients with CD arriving at routine follow-up. Subjective cognitive complaints, depression, anxiety, fatigue, and sleep were evaluated by validated questionnaires. CD characteristics, blood tests, and Crohn's disease activity index were obtained. Nutritional risk index was derived from serum albumin and change in body weight. Montreal cognitive assessment was used for screening. Patients with either subjective cognitive complaints or Montreal cognitive assessment score ≤ 26 were tested by a computerized cognitive testing battery, with analysis of scores in 7 cognitive domains (CogDs) and an average of the CogD scores-global cognitive score (GCS). Impaired CogD was defined as scoring more than 1 SD below age and education adjusted average.

RESULTS

A total of 105 patients were recruited and 61 were tested with computerized cognitive testing battery. Mean age was 39 ± 13 and mean education years were 14 ± 2. The most commonly impaired CogDs were information processing speed (33%) and verbal function (28%). Crohn's disease activity index, nutritional risk index, and hemoglobin were significantly correlated with GCS (r = -0.34, 0.39, 0.33; P = 0.007, 0.003, 0.01). Linear regression revealed significant correlations between Crohn's disease activity index, nutritional risk index, and GCS (β = -0.3, 0.29; P = 0.03, 0.04), independent of depression. This model explained 24% of the variance in GCS.

CONCLUSIONS

Cognitive performance is related to CD activity and nutritional status. The results provide insight into potential influence of nutrition and inflammation on cognitive function. Further studies on cognitive function of patients with CD are warranted.

Dinitrobenzene sulphonic acid-induced colitis impairs spatial recognition memory in mice: roles of N-methyl D-aspartate receptors and nitric oxide

RATIONALE

Many peripheral diseases are associated with a decline in cognitive function. In this regard, there have been reports of patients with inflammatory bowel disease and an otherwise unexplained memory impairment.

OBJECTIVES

We sought to assess the memory performance of mice with colitis. We also investigated the roles of N-methyl D-aspartate (NMDA) receptors and nitric oxide (NO) as possible mediators of colitis-induced amnesia.

METHODS

To induce colitis, male NMRI mice were intrarectally injected with a solution containing dinitrobenzene sulfonic acid (DNBS; 4 mg in 100 μl) under anesthesia. Three days after intrarectal DNBS instillation, spatial recognition and associative memories were assessed by the Y-maze and passive avoidance tasks, respectively. The NMDA antagonists, MK-801 and memantine, and the inducible NO synthase (iNOS) inhibitor, aminoguanidine, were injected intraperitoneally 45 min before the Y-maze task.

RESULTS

Induction of colitis by DNBS impaired spatial recognition memory in the Y-maze task but had no effect on step through latencies in the passive avoidance test. Colitis-induced amnesia was reversed by administering specific doses of MK-801 and memantine (30 μg/kg and 1 mg/kg, respectively) suggesting dysregulated NMDA receptor activation as an underlying mechanism. No effect was seen with lower and higher doses of these drugs, resulting in a bell-shaped dose response curve. Colitis-induced amnesia was also inhibited by aminoguanidine (50 mg/kg), implicating a role for iNOS activation and neuroinflammation in this phenomenon.

CONCLUSION

DNBS-induced colitis impairs memory through NMDA receptor overstimulation and NO overproduction.

Chronic intestinal inflammation alters hippocampal neurogenesis

BACKGROUND

Adult neurogenesis in the subgranular zone of the hippocampus is involved in learning, memory, and mood control. Decreased hippocampal neurogenesis elicits significant behavioral changes, including cognitive impairment and depression. Inflammatory bowel disease (IBD) is a group of chronic inflammatory conditions of the intestinal tract, and cognitive dysfunction and depression frequently occur in patients suffering from this disorder. We therefore tested the effects of chronic intestinal inflammation on hippocampal neurogenesis.

METHODS

The dextran sodium sulfate (DSS) mouse model of IBD was used. Mice were treated with multiple-cycle administration of 3% wt/vol DSS in drinking water on days 1 to 5, 8 to 12, 15 to 19, and 22 to 26. Mice were sacrificed on day 7 (acute phase of inflammation) or day 29 (chronic phase of inflammation) after the beginning of the treatment.

RESULTS

During the acute phase of inflammation, we found increased plasma levels of IL-6 and TNF-α and increased expression of Iba1, a marker of activated microglia, accompanied by induced IL-6 and IL-1β, and the cyclin-dependent kinase inhibitor p21(Cip1) (p21) in hippocampus. During the chronic phase of inflammation, plasma levels of IL-6 were elevated. In the hippocampus, p21 protein levels were continued to be induced. Furthermore, markers of stem/early progenitor cells, including nestin and brain lipid binding protein (BLBP), and neuronal marker doublecortin (DCX) were all down-regulated, whereas glial fibrillary acidic protein (GFAP), a marker for astroglia, was induced. In addition, the number of proliferating precursors of neuronal lineage assessed by double Ki67 and DCX staining was significantly diminished in the hippocampus of DSS-treated animals, indicating decreased production of new neurons.

CONCLUSIONS

We show for the first time that chronic intestinal inflammation alters hippocampal neurogenesis. As p21 arrests early neuronal progenitor proliferation, it is likely that p21 induction during acute phase of inflammation resulted in the reduction of hippocampal neurogenesis observed later, on day 29, after the beginning of DSS treatment. The reduction in hippocampal neurogenesis might underlie the behavioral manifestations that occur in patients with IBD.

Absence of change in the gray matter volume of patients with ulcerative colitis in remission: a voxel based morphometry study

Background

Recent neuroimaging studies have investigated the brain involvement in patients with Crohn's disease (CD) and Ulcerative Colitis (UC). Functional studies found abnormalities in cognitive and emotional functions in CD and UC, while a voxel based morphometry (VBM) study found morphological changes in CD. We conducted a VBM study to compare the gray matter (GM) volume of UC patients and controls.

Methods

Eighteen UC patients in remission and eighteen healthy controls underwent structural MRI. VBM is a fully automated technique allowing identification of regional differences in the amount of GM, which enables an objective analysis of the whole brain. VBM was used for comparisons between patients and controls.

Results

UC patients were all in remission and had a mild clinical course. There were no differences between patients and controls in GM volume.

Conclusion

The brain morphology of patients with UC in remission is similar to controls. The lack of GM abnormalities in UC patients might reflect the mild clinical course of the inflammatory bowel disorder. Further research involving patients with different degrees of disease severity or during flares could shed more light on potential brain structural changes in UC.

Brain involvement in patients with inflammatory bowel disease: a voxel-based morphometry and diffusion tensor imaging study

OBJECTIVES

To investigate structural brain changes in inflammatory bowel disease (IBD).

METHODS

Brain magnetic resonance imaging (MRI) was performed on 18 IBD patients (aged 45.16 ± 14.71 years) and 20 aged-matched control subjects. The imaging protocol consisted of a sagittal-FLAIR, a T1-weighted high-resolution three-dimensional spoiled gradient-echo sequence, and a multisession spin-echo echo-planar diffusion-weighted sequence. Differences between patients and controls in brain volume and diffusion indices were evaluated using the voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) methods, respectively. The presence of white-matter hyperintensities (WMHIs) was evaluated on FLAIR images.

RESULTS

VBM revealed decreased grey matter (GM) volume in patients in the fusiform and the inferior temporal gyrus bilaterally, the right precentral gyrus, the right supplementary motor area, the right middle frontal gyrus and the left superior parietal gyrus (p < 0.05). TBSS showed decreased axial diffusivity (AD) in the right corticospinal tract and the right superior longitudinal fasciculus in patients compared with controls. A larger number of WMHIs was observed in patients (p < 0.05).

CONCLUSIONS

Patients with IBD show an increase in WMHIs and GM atrophy, probably related to cerebral vasculitis and ischaemia. Decreased AD in major white matter tracts could be a secondary phenomenon, representing Wallerian degeneration.

KEY POINTS

• There is evidence of central nervous system involvement in IBD. • Diffusion tensor imaging detects microstructural brain abnormalities in IBD. • Voxel based morphometry reveals brain atrophy in IBD.

Microbiota-gut-brain axis and cognitive function

Recent studies have demonstrated a clear association between changes in the microbiota and cognitive behavior. Intestinal dysbiosis, as modeled using GF mice (containing no microbiota), bacterial infection with an enteric pathogen, and administration of probiotics, can modulate cognitive behavior including learning and memory. This chapter will highlight recent findings in both human and animal studies indicating how changes in the composition and diversity of the microbiota can impact behavior and brain physiology in both disease states and in health. Cognitive behavior can not only be affected in cases of intestinal disease, but also manifests changes in extra-intestinal disease conditions.

An observational study of cognitive function in patients with irritable bowel syndrome and inflammatory bowel disease

BACKGROUND

Irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) are associated with several risk factors for developing cognitive impairment. These include altered cytokine levels, concurrent mood disorders, and the presence of chronic pain. This observational study aimed to explore the cognitive profile of patients with these conditions.

METHODS

Participants completed the Cardiff Cognitive Battery, a series of computerized neuropsychological performance tests that examine a range of cognitive function including psychomotor speed, memory, and intelligence. A progressive analysis of covariance model was used with demographic details, anxiety and depression scores entered as covariates. Fecal calprotectin levels were measured in IBD patients to determine disease activity.

KEY RESULTS

In total 231 participants were recruited (150 IBD patients, 40 IBS patients, and 41 healthy controls). IBD patients had significantly lower scores on fluid (p = 0.01) and crystalline intelligence tests (p = 0.028) compared to healthy volunteers, however, this reflected differences in concurrent mood disorder and level of education. When these factors were added as covariates, there was no significant difference between the groups. Duration and activity of disease did not affect cognitive function in IBD patients. Severity of symptoms had no impact on cognition in patients with IBS.

CONCLUSIONS & INFERENCES

The results of this observational study do not support the hypothesis that IBS or IBD have an intrinsic disease process that is associated with cognitive dysfunction. It is possible that concurrent mood disorders, in particular depression, may affect the cognitive performance of patients with IBD in specific tasks.

Psychosocial issues in pediatric inflammatory bowel disease: report of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition

Pediatric inflammatory bowel disease (IBD) can affect many areas of psychosocial functioning, and comprehensive medical care includes consideration of psychosocial issues as well as disease factors. The purpose of this clinical report is to review research on psychosocial functioning in pediatric IBD and to provide recommendations for care providers in the areas of psychopathology, health-related quality of life, and social, family, and school functioning. Youth with IBD are at increased risk for difficulty in all areas reviewed, and many psychosocial factors are associated with disease activity, which highlights the importance of monitoring psychosocial functioning as part of clinical care. Several interventions have empirical support or show promise for addressing psychosocial difficulty, and recommendations for monitoring and treating these issues are provided.

New insights into the brain involvement in patients with Crohn's disease: a voxel-based morphometry study

BACKGROUND

Crohn's disease (CD) is a chronic intestinal disorder characterized by overproduction of inflammatory cytokines and recurrent abdominal pain. Recently, brain morphological abnormalities in the pain matrix were found in patients with chronic pain disorders including irritable bowel syndrome. To investigate potential structural brain changes associated with CD, we used magnetic resonance imaging (MRI). Furthermore, we tested whether in patients gray matter (GM) volumes correlated with disease duration.

METHODS

Eighteen CD patients in remission and 18 healthy controls underwent structural MRI. Voxel-based morphometry (VBM) is a fully automated technique allowing identification of regional differences in the amount of GM enabling an objective analysis of the whole brain between groups of subjects. VBM was used for comparisons and correlation analysis.

KEY RESULTS

With respect to controls, CD patients exhibited decreased GM volumes in portion of the frontal cortex and in the anterior midcingulate cortex. Disease duration was negatively correlated with GM volumes of several brain regions including neocortical and limbic areas.

CONCLUSIONS & INFERENCES

Crohn's disease is associated with brain morphological changes in cortical and subcortical structures involved in nociception, emotional, and cognitive processes. Our findings provide new insight into the brain involvement in chronic inflammatory bowel disorders.

Gut memories: towards a cognitive neurobiology of irritable bowel syndrome

The brain and the gut are engaged in continual crosstalk along a number of pathways collectively termed the 'brain-gut axis'. Over recent years it has become increasingly clear that dysregulation of the axis at a number of levels can result in disorders such as irritable bowel syndrome (IBS). With recent advances in neuroimaging technologies, insights into the neurobiology of IBS are beginning to emerge. However the cognitive neurobiology of IBS has remained relatively unexplored to date. In this review we summarise the available data on cognitive function in IBS. Moreover, we specifically address three key pathophysiological factors, namely; stress, immune activation and chronic pain, together with other factors involved in the manifestation of IBS, and explore how each of these components may impact centrally, what neurobiological mechanisms might be involved, and consider the implications for cognitive functioning in IBS. We conclude that each factor addressed could significantly impinge on central nervous system function, supporting the view that future research efforts must be directed towards a detailed assessment of cognitive function in IBS.

Is childhood abuse or neglect associated with symptom reports and physiological measures in women with irritable bowel syndrome?

PURPOSE

Early childhood traumatic experiences (e.g., abuse or neglect) may contribute to sleep disturbances as well as to other indicators of arousal in patients with irritable bowel syndrome (IBS). This study compared women with IBS positive for a history of childhood abuse and/or neglect to women with IBS without this history on daily gastrointestinal (GI), sleep, somatic, and psychological symptom distress, polysomnographic sleep, urine catecholamines (CAs) and cortisol, and nocturnal heart rate variability (HRV).

METHODS

Adult women with IBS recruited from the community were divided into two groups: 21 with abuse/neglect and 19 without abuse/neglect based on responses to the Childhood Trauma Questionnaire (CTQ; physical, emotional, sexual abuse, or neglect). Women were interviewed, maintained a 30-day symptom diary, and slept in a sleep laboratory. Polysomnographic and nocturnal HRV data were obtained. First-voided urine samples were assayed for cortisol and CA levels.

RESULTS

Women with IBS positive for abuse/neglect history were older than women without this history. Among GI symptoms, only heartburn and nausea were significantly higher in women with abuse/neglect. Sleep, somatic, and psychological symptoms were significantly higher in women in the abuse/neglect group. With the exception of percentage of time in rapid eye movement (REM) sleep, there were few differences in sleep-stage variables and urine hormone levels. Mean heart rate interval and the natural log of the standard deviation of RR intervals for the entire sleep interval (Ln SDNN) values were lower in those who experienced childhood abuse/neglect.

CONCLUSION

Women with IBS who self-report childhood abuse/neglect are more likely to report disturbed sleep, somatic symptoms, and psychological distress. Women with IBS should be screened for adverse childhood events including abuse/neglect.

Factors associated with irritable bowel syndrome symptoms in hemodialysis patients

AIM: To investigate clinical characteristics associated with the presence of irritable bowel syndrome (IBS) symptoms in hemodialysis (HD) patients.

METHODS: This was a cross-sectional study. A questionnaire based on the Bowel Disease Questionnaire that records gastrointestinal symptoms was given to 294 patients in 4 dialysis centers. A total of 196 (67%) subjects returned the survey. A multivariable logistic regression model was used to identify factors significantly associated with IBS symptoms.

RESULTS: Symptoms compatible with IBS were present in 27 (13.8%) subjects and independently associated with low post-dialysis serum potassium [OR = 0.258, 95% CI (0.075-0.891), P = 0.032], paracetamol use [OR = 3.159, 95% CI (1.214-8.220), P = 0.018], and Kidney Disease Quality of Life (KDQOL) cognitive function score [OR = 0.977, 95% CI (0.956-0.999), P = 0.042]. Univariate regressions were also performed and the reported significance is for multivariate analysis. No association was detected for age, gender, depressed mood, smoking (present or past), body mass index, albumin level, Kt/V, sodium pre- or post-dialysis level, change in potassium level during HD, proton pump inhibitor or H2 blocker use, aspirin use, residual diuresis, hepatitis B or C infection, diabetes mellitus, marital status and education level.

CONCLUSION: This study examined potential risk factors for symptoms compatible with IBS in HD patients and identified an association with paracetamol use, post-dialysis potassium level and KDQOL-cognitive function score.