Dementia Spectrum Disorders Research Articles

TBK1 p.Y153Qfs*9 variant may be associated with young-onset, rapidly progressive amyotrophic lateral sclerosis through a haploinsufficiency mechanism.

TBK1 variants have been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia spectrum disorder. The current study elucidated the clinical and molecular genetic features of a novel TBK1 variant identified in a patient with young-onset, rapidly progressive ALS. The coding regions of TBK1, SOD1, TARDBP, and FUS were genetically analyzed using Sanger sequencing. Repeat-primed PCR was used to survey the GGGGCC repeat in C9ORF72. The study participant underwent a comprehensive clinical evaluation. The functional effects of the TBK1 variant were analyzed through in vitro transfection studies. We identified a novel frameshift truncating TBK1 variant, c.456_457delGT (p.Y153Qfs*9), in a man with ALS. The disease initially manifested as right hand weakness at the age of 39 years but progressed rapidly, with the revised ALS Functional Rating Scale score declining at an average monthly rate of 1.92 points in the first year after diagnosis. The patient had no cognitive dysfunction. However, Technetium-99m single photon emission tomography indicated hypoperfusion in his bilateral superior and middle frontal cortices. In vitro studies revealed that the p.Y153Qfs*9 variant resulted in a truncated TBK1 protein product, reduced TBK1 protein expression, loss of kinase function, reduced interaction with optineurin, and impaired dimerization. The heterozygous TBK1 p.Y153Qfs*9 variant may be associated with young-onset, rapidly progressive ALS through a haploinsufficiency mechanism.

Choices of morbidity outcomes and concentration-response functions for health risk assessment of long-term exposure to air pollution.

Air pollution health risk assessment (HRA) has been typically conducted for all causes and cause-specific mortality based on concentration-response functions (CRFs) from meta-analyses that synthesize the evidence on air pollution health effects. There is a need for a similar systematic approach for HRA for morbidity outcomes, which have often been omitted from HRA of air pollution, thus underestimating the full air pollution burden. We aimed to compile from the existing systematic reviews and meta-analyses CRFs for the incidence of several diseases that could be applied in HRA. To achieve this goal, we have developed a comprehensive strategy for the appraisal of the systematic reviews and meta-analyses that examine the relationship between long-term exposure to particulate matter with an aerodynamic diameter smaller than 2.5 µm (PM2.5), nitrogen dioxide (NO2), or ozone (O3) and incidence of various diseases. To establish the basis for our evaluation, we considered the causality determinations provided by the US Environmental Protection Agency Integrated Science Assessment for PM2.5, NO2, and O3. We developed a list of pollutant/outcome pairs based on these assessments and the evidence of a causal relationship between air pollutants and specific health outcomes. We conducted a comprehensive literature search using two databases and identified 75 relevant systematic reviews and meta-analyses for PM2.5 and NO2. We found no relevant reviews for long-term exposure to ozone. We evaluated the reliability of these studies using an adaptation of the AMSTAR 2 tool, which assesses various characteristics of the reviews, such as literature search, data extraction, statistical analysis, and bias evaluation. The tool's adaptation focused on issues relevant to studies on the health effects of air pollution. Based on our assessment, we selected reviews that could be credible sources of CRF for HRA. We also assessed the confidence in the findings of the selected systematic reviews and meta-analyses as the sources of CRF for HRA. We developed specific criteria for the evaluation, considering factors such as the number of included studies, their geographical distribution, heterogeneity of study results, the statistical significance and precision of the pooled risk estimate in the meta-analysis, and consistency with more recent studies. Based on our assessment, we classified the outcomes into three lists: list A (a reliable quantification of health effects is possible in an HRA), list B+ (HRA is possible, but there is greater uncertainty around the reliability of the CRF compared to those included on list A), and list B- (HRA is not recommended because of the substantial uncertainty of the CRF). In our final evaluation, list A includes six CRFs for PM2.5 (asthma in children, chronic obstructive pulmonary disease, ischemic heart disease events, stroke, hypertension, and lung cancer) and three outcomes for NO2 (asthma in children and in adults, and acute lower respiratory infections in children). Three additional outcomes (diabetes, dementia, and autism spectrum disorders) for PM2.5 were included in list B+. Recommended CRFs are related to the incidence (onset) of the diseases. The International Classification of Diseases, 10th revision codes, age ranges, and suggested concentration ranges are also specified to ensure consistency and applicability in an HRA. No specific suggestions were given for ozone because of the lack of relevant systematic reviews. The suggestions formulated in this study, including CRFs selected from the available systematic reviews, can assist in conducting reliable HRAs and contribute to evidence-based decision-making in public health and environmental policy. Future research should continue to update and refine these suggestions as new evidence becomes available and methodologies evolve.

Association of plasma biomarkers with cognition, cognitive decline, and daily function across and within neurodegenerative diseases: Results from the Ontario Neurodegenerative Disease Research Initiative.

We investigated whether novel plasma biomarkers are associated with cognition, cognitive decline, and functional independence in activities of daily living across and within neurodegenerative diseases. Glial fibrillary acidic protein (GFAP), neurofilament light chain (NfL), phosphorylated tau (p-tau)181 and amyloid beta (Aβ)42/40 were measured using ultra-sensitive Simoa immunoassays in 44 healthy controls and 480 participants diagnosed with Alzheimer's disease/mild cognitive impairment (AD/MCI), Parkinson's disease (PD), frontotemporal dementia (FTD) spectrum disorders, or cerebrovascular disease (CVD). GFAP, NfL, and/or p-tau181 were elevated among all diseases compared to controls, and were broadly associated with worse baseline cognitive performance, greater cognitive decline, and/or lower functional independence. While GFAP, NfL, and p-tau181 were highly predictive across diseases, p-tau181 was more specific to the AD/MCI cohort. Sparse associations were found in the FTD and CVD cohorts and for Aβ42/40 . GFAP, NfL, and p-tau181 are valuable predictors of cognition and function across common neurodegenerative diseases, and may be useful in specialized clinics and clinical trials.

Clinical and genetic characteristics of patients with very early onset frontotemporal dementia

AbstractBackgroundFrontotemporal dementia (FTD) spectrum disorders may occur in patients who are under 45 years old, often posing a diagnostic challenge, yet little is known about the clinical presentation and underlying genetic causes in this age group.MethodAs part of a prospective study focused on FTD, 780 participants met the research criteria for an FTD spectrum disorder between 2002‐2021. Of these, 40 patients (5.1%, 18 females) presented with age at onset < 45 years and constituted the very early onset frontotemporal dementia (VEO‐FTD) group. Their research records were reviewed to delineate their clinical characteristics. A panel of 40 dementia and amyotrophic lateral sclerosis‐associated genes was screened for pathogenic genetic variation using standardized methods.ResultBehavioral variant of frontotemporal dementia was disproportionally represented in the VEO‐FTD group (n = 35, 87.5%) suggesting selective vulnerability of the social‐emotional brain networks to frontotemporal lobar degeneration underlying neuropathologies in this age range. The median age at first symptom was 39 (interquartile range (IQR) = 32‐42.2) years, and the median diagnostic delay from symptom onset was 4 (IQR 2‐8.25) years. Initial misdiagnosis with a primary psychiatric disorder was prevalent, occurring in 17 (42.3%) of patients, and was diverse including mood, psychotic, anxiety, and addictive disorders. In five patients (12.5%), positive psychotic symptoms were reported, mostly as a presenting symptom or arising within a year from the first symptom. Among the VEO‐FTD patients, 18 (45%) carried C9orf72, MAPT or UBQLN2 pathogenic variants.ConclusionFTD spectrum disorders may occur under the age of 45 and are often misdiagnosed. The high prevalence of monogenic causes in this age group warrants timely genetic testing, especially in the era of emerging gene‐specific therapies.

Association of plasma biomarkers with cognitive domains across three neurodegenerative diseases and cerebrovascular disease

AbstractBackgroundIt is critical to better understand the value of plasma biomarkers in predicting cognitive deficits before widespread use as diagnostic and prognostic tools in specialized clinics and as markers of neurodegenerative disease progression in trials. Herein, we investigate their association with five cognitive domains across three common neurodegenerative diseases and cerebrovascular disease.MethodPatients from the curated multi‐site Ontario Neurodegenerative Disease Research Initiative (ONDRI) were included in this study, classified by diagnostic group: Alzheimer’s disease/Mild cognitive impairment (AD/MCI, n = 126, age = 71.0±8.2, 55%M), frontotemporal dementia spectrum disorders (FTD, n = 53, age = 67.8±7.1, 64%M), Parkinson’s disease (PD, n = 140, age = 67.9±6.3, 78%M) and cerebrovascular disease (CVD, n = 161, age = 69.2±7.4, 68%M). Plasma concentrations of Aβ40 and Aβ42 (Aβ42/40 ratio), glial fibrillary acidic protein (GFAP), neurofilament light (NfL) and phosphorylated‐tau181 (p‐tau181) were measured using high‐sensitivity Simoa assays. Scores from a 26‐test comprehensive neuropsychological assessment were used to compute composite z‐scores for five cognitive domains: attention & working memory, executive function, language, memory, and visuospatial function. Linear regression models controlling for age, sex, education and APOE E4 allele were used to test the association between plasma biomarkers and cognitive domains in each group separately.ResultIn AD/MCI, higher levels of GFAP, NfL and p‐tau181 were all associated with worse attention & working memory, executive function, and memory. In PD, higher levels of NfL were associated with worse attention & working memory, executive function, and visuospatial function; higher levels of GFAP were also associated with worse executive function. In CVD, higher levels of GFAP were associated with worse executive function, memory and visuospatial function; higher levels of p‐tau181 were also associated with worse memory. In FTD, no associations were found.ConclusionPlasma biomarkers indicative of neuronal and glial pathology are useful to predict the severity of widespread cognitive deficits in AD/MCI, PD, and CVD. Interestingly, p‐tau181 predicted memory deficits in both AD/MCI and CVD, suggesting potential mixed disease or pathological overlap. Plasma Aβ42/40 does not appear to predict any cognitive deficits in any of the neurodegenerative diseases studied. As FTD is highly heterogeneous and had the least number of patients, we are possibly lacking power to detect effects in this group.

Psychopharmacological Medication Use in Frontotemporal Dementia at the Time of Diagnosis: Comparison with Alzheimer's Disease.

Due to the significant presence of neuropsychiatric symptoms in patients with frontotemporal dementia (FTD) spectrum disorders, psychiatric misdiagnoses, diagnostic delay, and use of psychiatric treatments are common prior to the FTD diagnosis. Furthermore, treatment of diagnosed FTD patients mainly relies on off-label psychopharmacological approaches. Currently, limited real-world data are available regarding the actual use of psychopharmacological medications in FTD. To evaluate psychopharmacological medication use at the time of FTD diagnosis. Psychopharmacological medication use was evaluated in a Finnish FTD cohort containing 222 FTD patients, including the major clinical disease phenotypes (behavioral, language, and motor variants) and genetic patients carrying the C9orf72 repeat expansion. A cohort of 214 Alzheimer's disease (AD) patients was used as a neurodegenerative disease reference group. Active use of psychopharmacological medications at the time of diagnosis was significantly more common in FTD compared to AD, especially in the case of antidepressants (26.1% versus 15.0%, OR = 2.01, p = 0.008), antipsychotics (23.9% versus 9.3%, OR = 3.15, p < 0.001), and mood-stabilizers (6.3% versus 1.9%, OR = 2.93, p = 0.085; not statistically significant), whereas the use of cholinesterase inhibitors or memantine was nearly nonexistent in FTD patients. Female gender and behavioral variant of FTD phenotype alongside with depressive and psychotic symptoms were the most prominent factors associating with the use of these medications among the FTD spectrum patients. Use of off-label psychopharmacological medication and polypharmacy is substantially common at the time of FTD diagnosis. This likely reflects the challenges in using symptom-driven treatment approaches, especially prior to the eventual diagnosis.

Clinical and genetic characteristics of patients with very early onset frontotemporal dementia (S39.007)

Clinical and genetic characteristics of patients with very early onset frontotemporal dementia (S39.007)

Addition of the FTD Module to the Neuropsychiatric Inventory improves classification of frontotemporal dementia spectrum disorders

Most neuropsychiatric symptoms (NPS) common in frontotemporal dementia (FTD) are currently not part of the Neuropsychiatric Inventory (NPI). We piloted an FTD Module that included eight extra items to be used in conjunction with the NPI. Caregivers of patients with behavioural variant FTD (n = 49), primary progressive aphasia (PPA; n = 52), Alzheimer’s dementia (AD; n = 41), psychiatric disorders (n = 18), presymptomatic mutation carriers (n = 58) and controls (n = 58) completed the NPI and FTD Module. We investigated (concurrent and construct) validity, factor structure and internal consistency of the NPI and FTD Module. We performed group comparisons on item prevalence, mean item and total NPI and NPI with FTD Module scores, and multinomial logistic regression to determine its classification abilities. We extracted four components, together explaining 64.1% of the total variance, of which the largest indicated the underlying dimension ‘frontal-behavioural symptoms’. Whilst apathy (original NPI) occurred most frequently in AD, logopenic and non-fluent variant PPA, the most common NPS in behavioural variant FTD and semantic variant PPA were loss of sympathy/empathy and poor response to social/emotional cues (part of FTD Module). Patients with primary psychiatric disorders and behavioural variant FTD showed the most severe behavioural problems on both the NPI as well as the NPI with FTD Module. The NPI with FTD Module correctly classified more FTD patients than the NPI alone. By quantifying common NPS in FTD the NPI with FTD Module has large diagnostic potential. Future studies should investigate whether it can also prove a useful addition to the NPI in therapeutic trials.

Co-occurring pathogenic variants in 6q27 associated with dementia spectrum disorders in a Peruvian family.

Evidence suggests that there may be racial differences in risk factors associated with the development of Alzheimer's disease and related dementia (ADRD). We used whole-genome sequencing analysis and identified a novel combination of three pathogenic variants in the heterozygous state (UNC93A: rs7739897 and WDR27: rs61740334; rs3800544) in a Peruvian family with a strong clinical history of ADRD. Notably, the combination of these variants was present in two generations of affected individuals but absent in healthy members of the family. In silico and in vitro studies have provided insights into the pathogenicity of these variants. These studies predict that the loss of function of the mutant UNC93A and WDR27 proteins induced dramatic changes in the global transcriptomic signature of brain cells, including neurons, astrocytes, and especially pericytes and vascular smooth muscle cells, indicating that the combination of these three variants may affect the neurovascular unit. In addition, known key molecular pathways associated with dementia spectrum disorders were enriched in brain cells with low levels of UNC93A and WDR27. Our findings have thus identified a genetic risk factor for familial dementia in a Peruvian family with an Amerindian ancestral background.

The Burden of Dementia Spectrum Disorders and Associated Comorbid and Demographic Features.

Dementia spectrum disorders (DSDs) are a major cause of mortality and disability worldwide. DSDs encompass a large group of medical conditions that all ultimately lead to major functional and cognitive decline and disability. Demographic and comorbid conditions that are associated with DSDs have significant prognostic and preventive implications. In this article, we will discuss the global and regional burden of DSDs and cover key demographic and clinical conditions linked with DSDs. In the absence of disease-modifying treatments, the role of primary prevention has become more prominent. Implementation of preventive measures requires an understanding of predisposing and exacerbating factors.

Could Robots Empatize? A Review on The Employment of Social Robots in Mental Healthcare

The advances in artificial intelligence and robotics began to transform business and human relations. The employment of robots in health, education, entertainment and rehabilitation as well as industries introduced the concept of "social robots". Although there is no consensus on the definition of the concept, robots with some degree of autonomy and could conduct meaningful social interactions with humans are considered social robots. Studies have been conducted on the employment of social robots in mental health services. Studies have been conducted on the employment of social robots in mental health services. The effectiveness of social robots in the treatment of anxiety, stress, depression, anger, and eating disorders, especially dementia and autism spectrum disorder, has also been investigated. The question of “can robots empathize” is a significant topic in research that focus on human-robot interactions. Robotic empathy studies were conducted with two dimensions of human empathy for robots and robot empathy for humans and led to various philosophical and ethical discussions. Some argued that robot-human interaction leads to new opportunities in mental health services, while others criticized the use of robots since it could increase human solitude, blur the line between reality and virtuality perceptions and the distinction between ontological categories. The present literature review aimed to discuss the concepts of artificial intelligence, robots, and social robots, provide information about the studies on the employment of social robots in mental healthcare, and address the studies and views based on the question "can social robots empathize?"

Robotlar Empati Yapabilir mi? Sosyal Robotların Ruh Sağlığı Hizmetlerinde Kullanımı Üzerine Bir Derleme

The advances in artificial intelligence and robotics began to transform business and human relations. The employment of robots in health, education, entertainment and rehabilitation as well as industries introduced the concept of "social robots". Although there is no consensus on the definition of the concept, robots with some degree of autonomy and could conduct meaningful social interactions with humans are considered social robots. Studies have been conducted on the employment of social robots in mental health services. Studies have been conducted on the employment of social robots in mental health services. The effectiveness of social robots in the treatment of anxiety, stress, depression, anger, and eating disorders, especially dementia and autism spectrum disorder, has also been investigated. The question of “can robots empathize” is a significant topic in research that focus on human-robot interactions. Robotic empathy studies were conducted with two dimensions of human empathy for robots and robot empathy for humans and led to various philosophical and ethical discussions. Some argued that robot-human interaction leads to new opportunities in mental health services, while others criticized the use of robots since it could increase human solitude, blur the line between reality and virtuality perceptions and the distinction between ontological categories. The present literature review aimed to discuss the concepts of artificial intelligence, robots, and social robots, provide information about the studies on the employment of social robots in mental healthcare, and address the studies and views based on the question "can social robots empathize?"

Building the Research Path for Identifying and Validating Cognition‐related Digital Biomarkers

AbstractBackgroundCognitive dysfunction is a core feature of dementia spectrum disorders but simple screening tests are less sensitive to detect the deficits, especially in the very early stage of disease course using most standardized test instruments. This results in delayed discovery of disease onset and opportunity for early interventions that might be more effective in delaying or arresting progression. Digital phenotyping using a combination or hardware and software solutions provide potentially much more effective tools for helping clinicians identify subtle signs of cognition deficits and track them in a compressed timeline to confirm the accuracy of decreasing slope indicative of a neurodegenerative etiology.MethodsBeginning in 2017, 1,866 participants were recruited from the Dementia Center, Shuang Ho Hospital, New Taipei City, Taiwan and will be invited to use a smartphone application to collect digital phenotypes including information processing speed, response accuracy, error detection, and multitasking capacity and vocal patterns, such as speech pitch, tone, rhythm. Additionally, four groups of 100 new participants each will be recruited; cognitive unimpaired (CU), subjective cognitive decline (SCD), mild cognitive impairment (MCI) and mild dementia. In addition to the smartphone applications, these 400 participants will undergo additional testing that include the cognitive abilities screening instrument (CASI), Clinical Dementia Rating (CDR), Cookie Theft Picture Description, Eye Tracking Test, and gait/balance.ResultsDigital phenotyping profiles will be constructed for the cohort and validated against the smaller sample to determine those metrics that can serve as actual digital biomarkers. For the smaller sample, additional multi‐dimensional profiles will be constructed that add gait parameters (step length, stride length, step width, foot angle) and eye‐tracking (visual fixation changes, speed, duration) and determine to what extent they increase differential diagnostic accuracy.ConclusionsDigital assessment tools can be used for detecting changes in cognitively related behaviors associated with preclinical and early stage clinical dementia. Future research is needed to confirm the efficacy of these digital phenotypes to serve as digital biomarkers that have high prognostic and diagnostic accuracy.

Imaging in Neurodegenerative Syndromes: How to Recognize Dementia Spectrum Disorders?

neurological disorders journal Theranostics of Brain, Spine & Neural Disorders is an international, peer-reviewed online journal, publishing original research articles, review articles, short communications

Med Check: Psilocybin for OCD, Nuplazid Vote, and More

Med Check: Psilocybin for OCD, Nuplazid Vote, and More

Associations among clinical characteristics of sleep quality, cognitive performance, and brain architecture in Thai dementia spectrum disorders

AbstractBackgroundSleep disorders are increased with advancing age. Poor sleep quality is a risk factor for cognitive decline and dementia. We aimed 1) to explore the relationship between sleep quality, sleep architecture and cognition; 2) to investigate the association between brain volume and sleep parameters.MethodA total of 95 participants (70 female, mean age 67.18 ± 10 years) were included in this study. Thirty were those with major cognitive disorder patients, twenty‐five individuals had mild cognitive impairment (MCI), and forty were normal controls. Sleep parameters were measured using wrist actigraphy and subjective sleep questioners. The participants were evaluated with high‐resolution MRI. Three Dimensional sequences on Free‐Surfer morphometric procedure was used as the automated segmentation method to obtain brain volume. Demographic data, medical history, sleep characteristics, neuropsychological and mood evaluation were collected from participants.ResultMCI patients had significantly lower sleep efficiency than cognitive healthy persons, 81.30 + 7 .39 % vs. 85.12 + 5.09 %, p=0.04. 66 % of the participants had poor sleep quality. Prevalence of probable REM sleep behavior disorder (RBD) and restless leg syndrome was high in dementia group. Longer sleep latency was associated with worse performance on global cognition. Total sleep time was associated with entorhinal corex volume and hippocampal volume. Sleep latency was associated with hippocampal volumeConclusionSleep disorders were common in both cognitively healthy persons and dementia spectrum disorders. Lower sleep quality and disturbance of sleep maintenance were associated with the development of cognitive impairment. The causes and the consequences of poor sleep quality in patients with dementia spectrum disorders needed to be explored.

Diagnostic value of plasma P‐tau217 in frontotemporal dementia spectrum disorders

AbstractBackgroundFrontotemporal dementia spectrum disorders (FTD) display complex neuropathological substrates and poor clinicopathological correlations, which hinders therapy development. Plasma P‐tau217 is an emerging tool to screen for Alzheimer’s disease (AD) pathology and may have diagnostic value in FTD.MethodPlasma P‐tau217 was measured cross‐sectionally by electrochemiluminescence in FTD patients referred to ALLFTD from ARTFL (n = 628, 45.7% female, median age 66 ± 12 years). P‐tau217 differences by baseline phenotype, disease severity and genotype were determined with non‐parametric tests and general linear models. Associations between P‐tau217 and measures of disease severity and neuropsychological performance were determined with linear regressions corrected for age, sex, phenotype and APOE.ResultThe sample included 33% behavioral variant FTD, 23.6% primary progressive aphasia (PPA), 28.5% atypical parkinsonism, 1.6% amnestic dementia (AmDem), 2.8% FTD/motoneuron disease, 3% mild cognitive/behavioral impairment and 7.5% healthy controls. Only 1.6% carried FTD‐causing mutations. P‐tau217 was not related to age (r = 0.034, 95%CI ‐0.03 – 0.12, p = 0.4). Compared to controls (0.18 ± 0.07 pg/mL), P‐tau217 was elevated only in AmDem (0.58 ± 0.9 pg/mL, p = 0.001) and logopenic PPA (lvPPA, 0.71 ± 0.62 pg/mL p &lt; 0.001). P‐tau217 ≥ 0.42 pg/mL effectively discriminated AmDem and lvPPA from all other phenotypes (AUC 0.87, 95%CI 0.77 – 0.96, p = 0.001, 77% sensitivity, 92% specificity). AmDem (60%) and lvPPA (91.7%) had the highest prevalence of high (≥ 0.42 pg/mL) P‐tau217, and the highest prevalence of APOE4 (AmDem 40%, lvPPA 63.6%). APOE4 carriers (0.23 ± 0.22 pg/mL) had higher P‐tau217, than non‐carriers (0.19 ± 0.09 pg/mL), regardless of phenotype (APOE effect p = .002, APOE x phenotype, p = 0.44). P‐tau217 was associated with worse clinical severity, mood, memory and executive function, but not with worse motor symptoms or social cognition.ConclusionWhen FTD is suspected, high plasma P‐tau217 is strongly associated with amnestic dementia and logopenic PPA phenotypes. Pending completion of ongoing neuropathological, CSF and molecular neuroimaging analyses, the data support the use of plasma P‐tau217 to identify atypical AD as a cause or AD as a co‐pathology contributing to FTD clinical presentation.

Inflammatory Bowel Disease and Patients With Mental Disorders: What Do We Know?

Inflammatory bowel disease (IBD) is a multisystemic disease with a wide range of extraintestinal manifestations in both ulcerative colitis and Crohn’s disease, while increasing evidence supports the interaction between gut and central nervous system, described as “gut-brain axis”. According to epidemiological studies, it seems that patients with IBD present more frequently with impaired mental status compared to the general population, leading to diagnostic and management problems in this group of patients. The association between IBD and mental disorders, such as dementia and autism spectrum disorders, has not been fully clarified; genetic factors and the gut-brain axis seem to be involved. The purpose of this review is to present and analyze the epidemiological data about this issue, describe the possible pathogenetic mechanisms and discuss some considerations about the management of patients with IBD and impaired mental status. J Clin Med Res. 2021;13(9):466-473 doi: https://doi.org/10.14740/jocmr4593

Inflammatory Bowel Disease and Patients With Mental Disorders: What Do We Know?

Inflammatory bowel disease (IBD) is a multisystemic disease with a wide range of extraintestinal manifestations in both ulcerative colitis and Crohn’s disease, while increasing evidence supports the interaction between gut and central nervous system, described as “gut-brain axis”. According to epidemiological studies, it seems that patients with IBD present more frequently with impaired mental status compared to the general population, leading to diagnostic and management problems in this group of patients. The association between IBD and mental disorders, such as dementia and autism spectrum disorders, has not been fully clarified; genetic factors and the gut-brain axis seem to be involved. The purpose of this review is to present and analyze the epidemiological data about this issue, describe the possible pathogenetic mechanisms and discuss some considerations about the management of patients with IBD and impaired mental status.

Structure of the human C9orf72-SMCR8 complex reveals a multivalent protein interaction architecture.

A major cause of familial amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) spectrum disorder is the hexanucleotide G4C2 repeat expansion in the first intron of the C9orf72 gene. Many underlying mechanisms lead to manifestation of disease that include toxic gain-of-function by repeat G4C2 RNAs, dipeptide repeat proteins, and a reduction of the C9orf72 gene product. The C9orf72 protein interacts with SMCR8 and WDR41 to form a trimeric complex and regulates multiple cellular pathways including autophagy. Here, we report the structure of the C9orf72-SMCR8 complex at 3.8 Å resolution using single-particle cryo-electron microscopy (cryo-EM). The structure reveals 2 distinct dimerization interfaces between C9orf72 and SMCR8 that involves an extensive network of interactions. Homology between C9orf72-SMCR8 and Folliculin-Folliculin Interacting Protein 2 (FLCN-FNIP2), a GTPase activating protein (GAP) complex, enabled identification of a key residue within the active site of SMCR8. Further structural analysis suggested that a coiled-coil region within the uDenn domain of SMCR8 could act as an interaction platform for other coiled-coil proteins, and its deletion reduced the interaction of the C9orf72-SMCR8 complex with FIP200 upon starvation. In summary, this study contributes toward our understanding of the biological function of the C9orf72-SMCR8 complex.