Cognitive function in people with chronic illness: inflammatory bowel disease and irritable bowel syndrome

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.

Gastrointestinal Changes and Alzheimer's Disease

BACKGROUND

There is a well-described mechanism of communication between the brain and gastrointestinal system in which both organs influence the function of the other. This bi-directional communication suggests that disease in either organ may affect function in the other.

OBJECTIVE

To assess whether the evidence supports gastrointestinal system inflammatory or degenerative pathophysiology as a characteristic of Alzheimer's disease (AD).

METHODS

A review of both rodent and human studies implicating gastrointestinal changes in AD was performed.

RESULTS

Numerous studies indicate that AD changes are not unique to the brain but also occur at various levels of the gastrointestinal tract involving both immune and neuronal changes. In addition, it appears that numerous conditions and diseases affecting regions of the tract may communicate to the brain to influence disease.

CONCLUSION

Gastrointestinal changes represent an overlooked aspect of AD, representing a more system influence of this disease.

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.

Dietary Fiber and the Hippocampal Neurogenic Niche in a Model of Pelvic Radiotherapy

We sought to determine whether radiation to the colorectum had an impact on parameters of hippocampal neurogenesis and, if so, whether it could be modulated by a fiber-rich diet. Male C57BL/6J mice were fed a diet containing bioprocessed oat bran or a fiber-free diet, starting two weeks before colorectal irradiation with 4 fractions of 8 Gray or sham-irradiation. Diets were then continued for 1, 6 or 18 weeks, whereafter parameters of hippocampal neurogenesis were analyzed and correlated to serum cytokine levels. No statistically significant changes in neuronal markers or cell proliferation were found at one week post-irradiation. Six weeks post-irradiation there was a decreased cell proliferation in the subgranular zone that appeared slightly more pronounced in irradiated animals on a fiber-free diet and increased numbers of immature neurons per mm² dentate gyrus in the irradiated mice, with a statistically significant increase in mice on a fiber-rich diet. Microglial abundancy was similar between all groups. 18 weeks post-irradiation, a fiber-free diet had reduced the number of immature neurons, whereas irradiation resulted in an increase. Despite this, the population of mature neurons was stable. Analysis of serum cytokines revealed a negative correlation between MIP1-α and the number of immature neurons one week after irradiation, regardless of diet. Our findings show that pelvic radiotherapy has the potential to cause a long-lasting impact on hippocampal neurogenesis, and dietary interventions may modulate this impact. More in-depth studies on the relationship between irradiation-induced intestinal injury and brain health are warranted.

Irritable Bowel Syndrome, Depression, and Neurodegeneration: A Bidirectional Communication from Gut to Brain

Patients with irritable bowel syndrome (IBS) are increasingly presenting with a wide range of neuropsychiatric symptoms, such as deterioration in gastroenteric physiology, including visceral hypersensitivity, altered intestinal membrane permeability, and gastrointestinal motor dysfunction. Functional imaging of IBS patients has revealed several abnormalities in various brain regions, such as significant activation of amygdala, thinning of insular and anterior cingulate cortex, and increase in hypothalamic gray matter, which results in poor psychiatric and cognitive outcomes. Interrelations between the enteric and central events in IBS-related gastrointestinal, neurological, and psychiatric pathologies have compelled researchers to study the gut-brain axis-a bidirectional communication that maintains the homeostasis of the gastrointestinal and central nervous system with gut microbiota as the protagonist. Thus, it can be disrupted by any alteration owing to the gut dysbiosis or loss of diversity in microbial composition. Available evidence indicates that the use of probiotics as a part of a balanced diet is effective in the management of IBS and IBS-associated neurodegenerative and psychiatric comorbidities. In this review, we delineate the pathogenesis and complications of IBS from gastrointestinal and neuropsychiatric standpoints while also discussing the neurodegenerative events in enteric and central nervous systems of IBS patients and the therapeutic potential of gut microbiota-based therapy established on clinical and preclinical data.

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.

Cognitive Impairment in Adult Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

BACKGROUND

People living with inflammatory bowel disease (IBD) are exposed to multiple risk factors for cognitive impairment and frequently report cognitive difficulties. However, the presence of cognitive impairment in IBD has not been systematically reviewed.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we performed a systematic multidatabase search for cross-sectional and longitudinal studies comparing adults with IBD versus healthy controls for domain-specific cognitive function or scores on multidomain cognitive screening tools. For any domain reported by 3 or more studies, we conducted random-effects meta-analysis to calculate the standardized mean difference between groups; lower scores reflected poorer performance. Between-study heterogeneity was assessed using the I² statistic and study quality assessed using an IBD-modified Newcastle-Ottawa scale.

RESULTS

Of 8302 articles screened, 12 studies (n = 687) were included in the qualitative synthesis and 11 in meta-analyses. All studies were cross-sectional. Studies generally excluded people with active IBD and older adults. Despite no significant differences on multidomain screening tools such as the Mini Mental State Examination (-0.27 [95% confidence interval -0.68, 0.08], P = 0.14), people with IBD showed significant deficits compared with healthy controls in attention (standardized mean difference -0.36 [-0.60, -0.12], P = 0.003, I² = 0%), executive function (standardized mean difference -0.45 [-0.77, -0.13, P = 0.005, I² = 42.5%), and specifically in working memory (standardized mean difference -0.58 [-0.85, -0.30], P < 0.001, I² = 0%). Deficits in learning and recall were nonsignificant (P = 0.089) and other domains insufficient for meta-analysis.

CONCLUSIONS

People with IBD show deficits in attention and executive function, particularly in working memory, suggesting that cognitive impairment is a potential extraintestinal manifestation of IBD.

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.

Neuropsychological function is related to irritable bowel syndrome in women with premenstrual syndrome and dysmenorrhea

BACKGROUND

There is increasing evidence demonstrating the co-occurrence of primary dysmenorrhea (PD), premenstrual syndrome (PMS), and irritable bowel syndrome (IBS) in women. This study aimed to investigate whether women who have symptoms of IBS in addition to PD and PMS also report more severe or frequent menstruation-associated symptoms and psychological complications compared to women with PD and PMS alone.

METHODS

The study group included 182 female University students aged 18-25 years. IBS was diagnosed using the Rome III criteria. The severity of PMS and PD was determined using a 10-point visual analog scale and PSST (Premenstrual Syndrome Screening Tool), respectively. Neuropsychological functions including cognitive function, depression score, anxiety score, stress, insomnia, daytime sleepiness, quality of life and personality were assessed using standard questionnaires.

RESULTS

Of the 182 young females, 31 (17.0%) had IBS. Average days of bleeding during the menstrual cycle and mean pain severity on the PSST scale were significantly greater in the group with IBS compared to the non-IBS group (p < 0.01). The non-IBS individuals scored more favorably than the women with IBS with respect to severity of depression, insomnia, daytime sleepiness (p < 0.05). The PSST scores were significantly correlated with scores for depression (r = 0.29; p < 0.001), anxiety (r = 0.28; p < 0.001), stress (r = 0.32; p < 0.001), insomnia (r = 0.34; p < 0.001) and daytime sleepiness (r = 0.31; p < 0.001); while, they were negatively correlated with cognitive abilities (r = - 0.20; p = 0.006) and quality of life (r = - 0.42; p < 0.001). Linear regression analysis showed that the PSST scores were possibly significant factors in determining the scores for depression, anxiety, stress, quality of life, insomnia and daytime sleepiness (p < 0.05).

CONCLUSION

IBS is related to psychological comorbidities, in particular depression, sleep problems and menstrual-associated disorders. IBS may exacerbate the features of PMS which should be taken into account in the management of PMS.

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.

Altered cognitive function in systemic lupus erythematosus and associations with inflammation and functional and structural brain changes

OBJECTIVES

Cognitive dysfunction (CD) is common in systemic lupus erythematosus (SLE) but the cause remains unclear and treatment options are limited. We aimed to compare cognitive function in SLE and healthy controls (HCs) using both behavioural and neuroimaging techniques.

METHODS

Patients with SLE with stable disease and HCs were recruited. Clinical and psychological data were collected along with a blood sample for relevant biomarkers. Neurocognitive function was assessed using tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) and functional magnetic resonance imaging (fMRI) was used to examine brain responses to working memory (WM) and emotional processing (facial emotional recognition task, FERT) tasks.

RESULTS

Compared with HCs (n=30), patients with SLE (n=36) scored higher on measures of depression, fatigue and had higher hsCRP (p=0.013), IL-6 (p=0.003) and B lymphocyte stimulator (p<0.001). Patients with SLE had poorer performance on a task of sustained attention (p=0.002) and had altered brain responses, particularly in default mode network (DMN) regions and the caudate, during the WM task. Higher organ damage and higher VCAM-1 were associated with less attenuation of the DMN (p=0.005 and p=0.01, respectively) and lower BOLD signal in the caudate areas (p=0.005 and p=0.001, respectively). Increased IL-6 was also associated with lower BOLD signal in caudate areas (p=0.032).

CONCLUSIONS

Sustained attention was impaired in patients with SLE. Poor attenuation of the DMN may contribute to cognitive impairments in SLE and our data suggest that in addition to mood and fatigue inflammatory mechanisms and organ damage impact cognitive functioning in SLE. The multifaceted nature of CD in SLE means any therapeutic interventions should be individually tailored.

Comorbid anxiety, depression, and cognition in MS and other immune-mediated disorders

OBJECTIVE

To determine whether anxiety and depression are associated with cognition in multiple sclerosis (MS), and whether these associations are similar in other immune-mediated inflammatory diseases (IMID; including inflammatory bowel disease [IBD] and rheumatoid arthritis [RA]) and in anxious/depressed individuals (ANX/DEP) without an IMID.

METHODS

Participants (MS: n = 255; IBD: n = 247; RA: n = 154; ANX/DEP: n = 308) completed a structured psychiatric interview, the Hospital Anxiety and Depression Scale, and cognitive testing, including the Symbol Digit Modalities Test, the California Verbal Learning Test, and Letter Number Sequencing test. Test scores were converted to age-, sex-, and education-adjusted z scores. We evaluated associations of anxiety and depression with the cognitive z scores using multivariate linear models, adjusting for disease cohort.

RESULTS

All cohorts exhibited higher rates of impairment (i.e., z less than or equal to -1.5) in the domains of processing speed, verbal learning, and delayed recall memory relative to general population norms. Higher levels of anxiety symptoms were associated with slower processing speed, lower verbal learning, and lower working memory performance (all p < 0.001); higher levels of depression symptoms were associated with slower processing speed. These associations did not differ across cohorts.

CONCLUSION

Anxiety and depression are associated with lower cognitive function in MS, with a similar pattern observed in persons with other IMID, including IBD and RA, and persons without an IMID. Managing symptoms of anxiety and of depression in MS, as well as other IMIDs, is important to mitigate their effect on cognition.

Antioxidant Capacity and Behavioral Relevance of a Polyphenolic Extract of Chrysanthellum americanum in a Rat Model of Irritable Bowel Syndrome

Chrysanthellum americanum L. (Vatke) is a medicinal plant from the Compositae family used in west-African traditional medicine, known for its flavonoid and saponin richness and for its strong antioxidant potential. In the present study, we assessed the effects of Chrysanthellum americanum polyphenolic extract in the psychological stress-induced rat model of irritable bowel syndrome (IBS), a chronic functional digestive tract disorder marked by immune and inflammatory-related disturbances of central nervous and peripheral intestinal systems, which is often associated with mood disorders including depression and anxiety. Consequently, memory impairment, anxiety and depression behavioral indicators, and cerebral oxidative stress biomarker dynamics were evaluated in a multifactorial heterotypic stress-exposed IBS rats after 6-day gavage with polyphenolic C. americanum extract (100 mg/kg body weight). Y-maze, elevated plus maze, and forced swimming tests were used for assessing behavioral responses. Administration of the extract exhibited significant anxiolytic and antidepressant-like effects coupled with significantly increased temporal lobe antioxidant enzyme specific activity (superoxide dismutase and glutathione peroxidase) and decreased malondialdehyde levels, a well-known lipid peroxidation marker. Furthermore, linear regression statistical analyses showed significant correlations between the oxidative stress parameters and behavioral tests. In conclusion, our results suggest that the administration of Chrysanthellum americanum polyphenolic extract could ameliorate mood and cognitive disturbances related to stress-induced in an IBS rat model. This could be also related to cerebral oxidative stress status attenuation.

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.

From the Bottom-Up: Chemotherapy and Gut-Brain Axis Dysregulation

The central nervous system and gastrointestinal tract form the primary targets of chemotherapy-induced toxicities. Symptoms associated with damage to these regions have been clinically termed chemotherapy-induced cognitive impairment and mucositis. Whilst extensive literature outlines the complex etiology of each pathology, to date neither chemotherapy-induced side-effect has considered the potential impact of one on the pathogenesis of the other disorder. This is surprising considering the close bidirectional relationship shared between each organ; the gut-brain axis. There are complex multiple pathways linking the gut to the brain and vice versa in both normal physiological function and disease. For instance, psychological and social factors influence motility and digestive function, symptom perception, and behaviors associated with illness and pathological outcomes. On the other hand, visceral pain affects central nociception pathways, mood and behavior. Recent interest highlights the influence of functional gut disorders, such as inflammatory bowel diseases and irritable bowel syndrome in the development of central comorbidities. Gut-brain axis dysfunction and microbiota dysbiosis have served as key portals in understanding the potential mechanisms associated with these functional gut disorders and their effects on cognition. In this review we will present the role gut-brain axis dysregulation plays in the chemotherapy setting, highlighting peripheral-to-central immune signaling mechanisms and their contribution to neuroimmunological changes associated with chemotherapy exposure. Here, we hypothesize that dysregulation of the gut-brain axis plays a major role in the intestinal, psychological and neurological complications following chemotherapy. We pay particular attention to evidence surrounding microbiota dysbiosis, the role of intestinal permeability, damage to nerves of the enteric and peripheral nervous systems and vagal and humoral mediated changes.

Altered Brain Excitability and Increased Anxiety in Mice With Experimental Colitis: Consideration of Hyperalgesia and Sex Differences

Crohn’s disease (CD) and ulcerative colitis (UC) are incurable lifelong inflammatory bowel diseases (IBD) with a rising worldwide incidence. IBD is characterized by diarrhea, rectal bleeding, severe cramping and weight loss. However, there is a growing evidence that IBD is also associated with anxiety- and depression-related disorders, which further increase the societal burden of these diseases. Given the limited knowledge of central nervous system (CNS) changes in IBD, we investigated CNS-related comorbidities in a mouse model of experimental colitis induced by dextran sulfate sodium (DSS) administration in drinking water for 5 days. In male and female C57BL6J mice, DSS treatment caused increased brain excitability, revealed by a decrease in seizure onset times after intraperitoneal administration of kainic acid. Moreover, both sexes showed increased anxiety-related behavior in the elevated plus-maze (EPM) and open field (OF) paradigms. We assessed somatic pain levels, because they may influence behavioral responses. Only male mice were hyperalgesic when tested with calibrated von Frey hairs and on the hotplate for mechanical and thermal pain sensitivity respectively. Administration of diazepam (DZP; ip, 1 mg/kg) 30 min before EPM rescued the anxious phenotype and improved locomotion, even though it significantly increased thermal sensitivity in both sexes. This indicates that the altered behavioral response is unlikely attributable to an interference with movement due to somatic pain in females. We show that experimental colitis increases CNS excitability in response to administration of kainic acid, and increases anxiety-related behavior as revealed using the EPM and OF tests.

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.

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.

Pain moderates changes in psychological flexibility but not substance use symptoms during substance use disorder treatment

Pain-related problems frequently complicate substance use disorder (SUD) course and prognosis. However, it is unclear if the negative outcomes associated with co-occurring pain are due to its link with greater SUD severity, disruption of SUD treatment processes, or connection to a third psychological process. The current study modeled the longitudinal effects of pain during a 4-week intensive outpatient treatment (IOP) on SUD symptoms and limited psychological flexibility (PF), a common feature of psychological well being that is commonly restricted in both SUD and pain patients. After controlling for initial severity of SUD symptoms, current pain level at treatment intake moderated change in a sub-component of PF, values commitment, but not SUD symptoms during the IOP. During the treatment, pain level also limited improvement in PF but not self-reported SUD symptoms. Targeting additional increases in psychological flexibility surrounding commitment to values during SUD treatment may help improve outcomes among patients who began treatment with significant pain symptoms.

Care of inflammatory bowel disease patients in remission

Inflammatory bowel disease (IBD) comprises two distinct conditions: ulcerative colitis and Crohn’s disease, both of which are chronic, relapsing disorders carrying significant morbidity, mortality and healthcare costs. With growing attention to coordinated healthcare for patients with chronic systemic diseases, this review focuses on the care of IBD patients in remission, their concerns, quality of life, follow-up, the role of primary care physicians and the IBD-specific aspects of long-term care. We did an extensive PubMed search for articles pertaining to IBD patients in remission and, along with the authors’ experience, formulated a comprehensive review. The difficulties faced by IBD patients in remission include but are not limited to education and employment concerns, psychosocial issues, problems related to health insurance, nutrition, fertility and infections. This review also addresses newer treatment modalities, the debatable effects of smoking on IBD and the importance of vaccination. IBD in remission can be a challenge due to its multifaceted nature; however, with a coordinated approach by gastroenterologists and other involved practitioners, several of these issues can be addressed.

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.

Endoscopic sinus surgery improves cognitive dysfunction in patients with chronic rhinosinusitis

BACKGROUND

Patients with chronic rhinosinusitis (CRS) have been found to have cognitive deficit, as identified using the Cognitive Failures Questionnaire (CFQ), but the exact etiology of cognitive decline is unknown. In this study we aimed to determine whether improvement in concomitant inflammation and disease burden in CRS, using endoscopic sinus surgery (ESS), improves cognitive deficit. We also sought to identify comorbid conditions that effect improvement likelihood.

METHODS

Study participants (n = 247) with and without nasal polyposis (CRSwNP, CRSsNP) were prospectively enrolled in this multi-institutional, observational outcomes study. Pre- and postoperative cognitive dysfunction was evaluated using the CFQ instrument. Quality of life (QOL) and disease burden was also evaluated using the Rhinosinusitis Disability Index (RSDI), the 22-item SinoNasal Outcome Test (SNOT-22), nasal endoscopy, computed tomography, and the 2-item Patient Health Questionnaire (PHQ-2).

RESULTS

Average CFQ total scores improved significantly (p = 0.012) after ESS for patients with follow-up (n = 141). Participants with CRSwNP (n = 51) reported significant postoperative improvements in mean CFQ total scores (p = 0.002) and CFQ distractibility and blunders domain scores (p ≤ 0.006). No significant postoperative improvement for any average CFQ score was found in CRSsNP (p > 0.086). The magnitude of postoperative improvement in CFQ total and domain mean scores was statistically similar between CRSsNP and CRSwNP (p > 0.115). Depressive disorder, identified using PHQ-2 screening, was the only comorbid condition significantly associated with measurable cognitive deficit (p < 0.001).

CONCLUSIONS

Patients with CRS have measurable cognitive decline, and ESS may modestly improve cognitive deficit/CFQ scores. Future investigations are needed to further elucidate the underlying mechanisms responsible for cognitive deficit in patients with CRS and significant associations with depression.

Toward a better understanding of the central consequences of intestinal inflammation

Inflammatory bowel diseases (IBDs), which include Crohn's disease and ulcerative colitis, are inflammatory diseases of the gastrointestinal tract. Quality of life for IBD patients is negatively affected by associated pain and gastrointestinal dysfunction, but also by serious behavioral symptoms that include depression, anxiety, fatigue, and cognitive dysfunction. Because these behavioral comorbidities are poorly understood, we have investigated them in a rat model of IBD caused by infusion of a hapten (trinitrobenzene sulfonic acid (TNBS)) into the lower colon. TNBS colitis has many similarities to Crohn's disease, and we have found that it is associated with changes in central nervous system function. TNBS-treated animals have lowered seizure thresholds, which resolve following remission, and hippocampal slices from such animals display increased excitability. There are significant changes in excitatory, AMPA receptor-mediated transmission, in part due to increased numbers of AMPA receptors lacking the GluR2 subunit. Long-term potentiation and depression are reduced in colitic animals, and the synaptic alterations are reversed if microglial activation and tumor necrosis factor α synthesis within the brain are blocked.

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.

Cognitive Functions and Depression in Patients with Irritable Bowel Syndrome

Background. Irritable bowel syndrome (IBS) is associated with depression and depression with impaired cognitive functions. The primary aim was to study associations between depression and cognitive functions in patients with IBS. Methods. IBS (according to the Rome III criteria), cognitive functions (evaluated with a set of neuropsychological tests), and depression (measured with Beck Depression Inventory II and Montgomery-Åsberg Depression Scale) were analysed in patients with idiopathic depression and in patients with unspecified neurological symptoms. Results. 18 and 48 patients with a mean age of 47 and 45 years were included in the "Depression" and "Neurological" group, respectively. In the "Depression" group, the degree of depression was significantly higher in patients with IBS than in those without. Depression was associated with impaired cognitive function in 6 out of 17 neuropsychological tests indicating reduced set shifting, verbal fluency, attention, and psychomotor speed. IBS was statistically significantly associated with depression but not with any of the tests for cognitive functions. Conclusions. IBS was associated with depression but not with impaired cognitive functions. Since the idiopathic depression was associated with cognitive deficits, the findings could indicate that the depression in patients with IBS differs from an idiopathic depression.

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.

Irritable bowel syndrome: A microbiome-gut-brain axis disorder?

Irritable bowel syndrome (IBS) is an extremely prevalent but poorly understood gastrointestinal disorder. Consequently, there are no clear diagnostic markers to help diagnose the disorder and treatment options are limited to management of the symptoms. The concept of a dysregulated gut-brain axis has been adopted as a suitable model for the disorder. The gut microbiome may play an important role in the onset and exacerbation of symptoms in the disorder and has been extensively studied in this context. Although a causal role cannot yet be inferred from the clinical studies which have attempted to characterise the gut microbiota in IBS, they do confirm alterations in both community stability and diversity. Moreover, it has been reliably demonstrated that manipulation of the microbiota can influence the key symptoms, including abdominal pain and bowel habit, and other prominent features of IBS. A variety of strategies have been taken to study these interactions, including probiotics, antibiotics, faecal transplantations and the use of germ-free animals. There are clear mechanisms through which the microbiota can produce these effects, both humoral and neural. Taken together, these findings firmly establish the microbiota as a critical node in the gut-brain axis and one which is amenable to therapeutic interventions.

Psychosocial factors involved in memory and cognitive failures in people with myalgic encephalomyelitis/chronic fatigue syndrome

BACKGROUND

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by persistent emotional, mental, and physical fatigue accompanied by a range of neurological, autonomic, neuroendocrine, immune, and sleep problems. Research has shown that psychosocial factors such as anxiety and depression as well as the symptoms of the illness, have a significant impact on the quality of life of people with ME/CFS. In addition, individuals may suffer from deficits in memory and concentration. This study set out to explore the relationships between variables which have been found to contribute to cognitive performance, as measured by prospective and retrospective memory, and cognitive failures.

METHODS

Eighty-seven people with ME/CFS answered questionnaires measuring fatigue, depression, anxiety, social support, and general self-efficacy. These were used in a correlational design (multiple regression) to predict cognitive function (self-ratings on prospective and retrospective memory), and cognitive failures.

RESULTS

Our study found that fatigue, depression, and general self-efficacy were directly associated with cognitive failures and retrospective (but not prospective) memory.

CONCLUSION

Although it was not possible in this study to determine the cause of the deficits, the literature in this area leads us to suggest that although the pathophysiological mechanisms of ME/CFS are unclear, abnormalities in the immune system, including proinflammatory cytokines, can lead to significant impairments in cognition. We suggest that fatigue and depression may be a result of the neurobiological effects of ME/CFS and in addition, that the neurobiological effects of the illness may give rise to both fatigue and cognitive deficits independently.

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.

Diffusion tensor imaging detects microstructural reorganization in the brain associated with chronic irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder characterized by recurring abdominal pain associated with alterations in bowel habits. We hypothesized that patients with chronic visceral pain associated with IBS may have microstructural differences in the brain compared with healthy control subjects (HCs), indicative of long-term neural reorganization of chronic pain pathways and regions associated with sensory integration. In the current study we performed population-based voxel-wise diffusion tensor imaging (DTI) comparisons and probabilistic tractography in a large sample of phenotyped patients with IBS (n=33) and in HCs (n=93). Patients had lower fractional anisotropy (FA) in thalamic regions, the basal ganglia (BG) and sensory/motor association/integration regions as well as higher FA in frontal lobe regions and the corpus callosum. In addition, patients had reduced mean diffusivity (MD) within the globus pallidus (GP) and higher MD in the thalamus, internal capsule, and coronal radiata projecting to sensory/motor regions, suggestive of differential changes in axon/dendritic density in these regions. Sex differences in FA and MD were also observed in the patients but not in HCs. Probabilistic tractography in patients confirmed a higher degree of connectivity between the thalamus and prefrontal cortex, as well as between the medial dorsal thalamic nuclei and anterior cingulate cortex, and a lower degree of connectivity between the GP and thalamus. Together, these results support the hypothesis that patients with chronically recurring visceral pain from IBS have long-term microstructural changes within the brain, particularly in regions associated with integration of sensory information and corticothalamic modulation.

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.

Cognitive functioning and depressive symptoms in adolescents with inflammatory bowel disease

AIM: To investigate cognitive functioning and depressive symptoms in adolescents with inflammatory bowel disease (IBD).

METHODS: A neuropsychological test battery, including subtests of the Wechsler Adult Intelligence Scale-Revised and III, Wechsler Memory Scale-Revised, California Verbal Learning Test (CVLT), Stroop Color-Word Test, and Trail Making Test, which assessed verbal and visual short- and long-term memory, processing speed, logical reasoning, verbal intelligence, attention, and executive functioning, was administered to 13- to 19-year-old patients with IBD (n = 34; active disease n = 20). Depressive symptoms were measured with the Beck Depression Inventory. The findings were compared with peers with non-acute juvenile idiopathic arthritis (JIA; n = 23). Patients with coexisting psychiatric disorders were excluded.

RESULTS: The IBD group, especially patients in the acute phase, made more perseverative errors in the CVLT test that assessed verbal memory than the JIA group (6.0 ± 4.3 vs 3.3 ± 2.9, P < 0.01), but no other differences between the IBD and JIA groups were observed in the neuropsychological tests. The difference was close to statistical significance, even when glucocorticoid medication was controlled for (P < 0.052). The IBD group had more depressive symptoms than the JIA group (7.9 ± 7.6 vs 4.0 ± 4.0, P < 0.05). Approximately one third of the IBD group had at least mild depressive symptoms, and those with acute illness had the highest scores. However, depressive symptoms were not related to the difference in the verbal memory test (perseverative errors in the CVLT) between the IBD and JIA groups.

CONCLUSION: Adolescents with acute IBD may have mild verbal memory problems but no major cognitive deficits compared to peers with JIA.

Neurodegenerative properties of chronic pain: cognitive decline in patients with chronic pancreatitis

Chronic pain has been associated with impaired cognitive function. We examined cognitive performance in patients with severe chronic pancreatitis pain. We explored the following factors for their contribution to observed cognitive deficits: pain duration, comorbidity (depression, sleep disturbance), use of opioids, and premorbid alcohol abuse. The cognitive profiles of 16 patients with severe pain due to chronic pancreatitis were determined using an extensive neuropsychological test battery. Data from three cognitive domains (psychomotor performance, memory, executive functions) were compared to data from healthy controls matched for age, gender and education. Multivariate multilevel analysis of the data showed decreased test scores in patients with chronic pancreatitis pain in different cognitive domains. Psychomotor performance and executive functions showed the most prominent decline. Interestingly, pain duration appeared to be the strongest predictor for observed cognitive decline. Depressive symptoms, sleep disturbance, opioid use and history of alcohol abuse provided additional explanations for the observed cognitive decline in some of the tests, but to a lesser extent than pain duration. The negative effect of pain duration on cognitive performance is compatible with the theory of neurodegenerative properties of chronic pain. Therefore, early and effective therapeutic interventions might reduce or prevent decline in cognitive performance, thereby improving outcomes and quality of life in these patients.

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.

Deteriorated executive functions in patients with successful surgery for pituitary adenomas compared with other chronically ill patients

Pituitary adenomas, even after successful treatment, are associated with cognitive impairments. It is unclear whether these deficits are a consequence of unspecific factors associated with having a chronic illness and whether the cognitive dysfunctions exceed those of other chronically ill patients. Thirty-eight patients with transsphenoidal surgery for pituitary adenomas and 38 patients undergoing L-thyroxine replacement therapy after thyroid surgery were studied neuropsychologically with established tests. Executive function was examined with the Trail-Making Test A and B, working memory with the digit span test, attention with the digit symbol test, verbal memory with the German version of the Auditory Verbal Learning and Memory Test, and general verbal intelligence by a vocabulary test. Attention (p = .007), attentional speed (p = .0004), executive control (p = .04), and working memory (p = .01), were significantly reduced in patients with pituitary adenomas compared with other chronically ill patients. In contrast, no differences were found between the groups for verbal memory (all subtests: p ≥ .06). Patients with successful surgery for pituitary adenomas show also in comparison with other chronically ill patients an increased risk for deficits in certain aspects of cognitive function, including attention and working memory, supporting the relevance of the brain lesion and its treatment for these dysfunctions.

Constructive thinking, rational intelligence and irritable bowel syndrome

AIM: To evaluate rational and experiential intelligence in irritable bowel syndrome (IBS) sufferers.

METHODS: We recruited 100 subjects with IBS as per Rome II criteria (50 consulters and 50 non-consulters) and 100 healthy controls, matched by age, sex and educational level. Cases and controls completed a clinical questionnaire (including symptom characteristics and medical consultation) and the following tests: rational-intelligence (Wechsler Adult Intelligence Scale, 3rd edition); experiential-intelligence (Constructive Thinking Inventory); personality (NEO personality inventory); psychopathology (MMPI-2), anxiety (state-trait anxiety inventory) and life events (social readjustment rating scale). Analysis of variance was used to compare the test results of IBS-sufferers and controls, and a logistic regression model was then constructed and adjusted for age, sex and educational level to evaluate any possible association with IBS.

RESULTS: No differences were found between IBS cases and controls in terms of IQ (102.0 ± 10.8 vs 102.8 ± 12.6), but IBS sufferers scored significantly lower in global constructive thinking (43.7 ± 9.4 vs 49.6 ± 9.7). In the logistic regression model, global constructive thinking score was independently linked to suffering from IBS [OR 0.92 (0.87-0.97)], without significant OR for total IQ.

CONCLUSION: IBS subjects do not show lower rational intelligence than controls, but lower experiential intelligence is nevertheless associated with IBS.

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

BACKGROUND

Many chronic illnesses are accompanied by impaired cognitive functioning. In people with Inflammatory Bowel Disease (IBD), there is some research to suggest a decrement in verbal IQ (VIQ), when compared to people with Irritable Bowel Syndrome (IBS) and healthy controls. Although this is an important finding, it is necessary to ensure that such deficits are not due to methodological problems such as the failure to take into account pre-morbid functioning.

METHODS

A total of 88 people (IBD, N = 29; IBS, N = 29; Controls, N = 30) completed the Wechsler Abbreviated Scale of Intelligence (WASI), the Wechsler Test of Adult Reading (WATR), the Trait Rumination Questionnaire (TRQ), the Center for Epidemiologic Studies Depression Scale (CES-D), and the General Health Questionnaire (GHQ-12).

RESULTS

We found evidence of a VIQ decrement in both IBD and IBS groups when measured against both healthy controls and against their own pre-morbid IQ scores (WTAR-Predicted WAIS-III IQ measures). However, the decrement was larger (and of clinical significance) in the IBD group but not in the IBS group.

CONCLUSION

Some tentative evidence is presented which suggests that poor VIQ performance may be due in part to interference from excessive rumination.

Hypervigilance in irritable bowel syndrome compared with organic gastrointestinal disease

OBJECTIVE

Irritable bowel syndrome (IBS) patients are suggested to selectively attend to gastrointestinal (GI) sensations compared with healthy controls. However, it remains unclear whether there are differences between IBS and other chronic GI disorders. We aimed to evaluate the presence of hypervigilance towards the GI tract in IBS compared with patients with organic GI diseases.

METHODS

We included 36 IBS patients and 40 age- and gender-matched patients with organic GI disease. They completed the Hospital Anxiety and Depression Scale (HADS) and underwent three tests: (1) word association-write down as many words as possible representing signs of disease; (2) word recognition (tachistoscope)-four categories of words (positive affects, non-GI symptoms, GI symptoms, negative affects) displayed for increasing time until identified; (3) word recollection-memorize words (10 GI symptoms, 10 positive affects, 10 negative affects).

RESULTS

The word-association task did not show group differences. IBS patients were significantly faster than organic GI patients at recognizing words representing GI symptoms (21 vs. 26 ms; P=.04) and negative affects (27 vs. 34 ms; P=.03), but also tended to be faster at recognizing positive affects (24 vs. 29 ms; P=.08) and non-GI symptoms (22 vs. 27 ms; P=.2). Both groups remembered a similar number of words, but IBS patients tended to recall more incorrect GI words than organic patients (1.3 vs. 1.0; P=.06). There were no group differences in HADS scores.

CONCLUSION

Compared to patients with organic GI disease, IBS patients seem to be hypervigilant for information regarding GI sensations and maybe also negative information.

New insights into the pathogenesis and pathophysiology of irritable bowel syndrome

The pathogenesis and pathophysiology of irritable bowel syndrome is complex and still incompletely known. Potential pathogenetic factors include genes, infectious events, psychological symptoms and other loosely defined environmental factors. Both alterations at the central and peripheral level are thought to contribute to the symptoms of irritable bowel syndrome, including psychosocial factors, abnormal gastrointestinal motility and secretion, and visceral hypersensitivity. Today irritable bowel syndrome is viewed upon as a disorder of dysregulation of the so-called brain-gut axis, involving abnormal function in the enteric, autonomic and/or central nervous systems, with peripheral abnormalities probably dominating in some patients and disturbed central processing of signals from the periphery in others. Lines of evidence also suggest that inflammation within the gastrointestinal tract may be of great importance in at least subgroups of irritable bowel syndrome patients. To conclude, a complex picture of the pathogenesis and pathophysiology of irritable bowel syndrome is emerging, with interactions between several different alterations resulting in the divergent symptom pattern in these patients.

Is there a link between Irritable Bowel Syndrome and left-handedness?: An exploratory study

Recent research has found that people with Irritable Bowel Syndrome (IBS) and those with Inflammatory Bowel Disease (IBD) show a relative deficit in verbal IQ, compared to their own performance IQ, and the IQ of a healthy comparison group. It has been suggested that the elevated prevalence of left-handedness shown in previous studies investigating people with IBD is due to compromised left-hemisphere development. This may be associated with a decrement in certain cognitive functions such as verbal IQ. A shift in brain dominance from left to right has been found in many atopic and immunological diseases as well as in autonomic dysfunctions. It was uncertain whether this would apply to people with IBS, a functional disorder in which the cause or causes remain unclear. Therefore, the aim of this preliminary study was to investigate whether people with IBS have an increased prevalence of left-handedness. It was found that there was an association between IBS and left-handedness, showing that further research on this association both in IBS and other functional disorders (as well as on the similarities between IBS and IBD) is warranted.

Sleep quality in patients with irritable bowel syndrome

AIM: To investigate the sleep quality in patients with irritable bowel syndrome(IBS) and its relationship with the patients psychiatric symptoms.

METHODS: The quality of sleep and psychiatric symptoms in consecutive 41 patients with IBS according to Rome II criteria were measured by Pittsburgh sleep quality index(PSQI) and symptom checklist-90(SCL-90), respectively. In the meantime, 37 matched heath controls and 35 patients matched patients with peptic ulcer diseases as controls were also evaluated. The relationship between PSQI and psychiatric symptoms was investigated by regression analysis.

RESULTS: Compared with health controls, IBS patients had more psychiatric symptoms(40.2±4.5, t = 2.63, P = 0.047), and higher scores of depression(0.64±0.24, t = 2.53, P = 0.020) and anxiety(0.67±0.30, t = 2.16, P = 0.016). Among IBS patients, the quality of sleep and daily functions significantly decreased. PSQI and sleep disturbances as well as soporific using was markedly increased. The scores of obsessive-compulsive(t = 2.60, P = 0.037), and mental factor(t = 2.71, P = 0.028) were higher in IBS patients than that in patients with peptic ulcer diseases. Multiple regression analysis showed negative relarionship between the quality of sleep and many psychiatric symptoms(R>0.195, P<0.05, respectively).

CONCLUSION: IBS patients have sleep disturbances associated psychiatric symptoms.