Antipsychotics in Alzheimer's Disease: Current Status and Therapeutic Alternatives

Psychosis and hyperactive behaviors, such as agitation and wandering, affect a significant proportion of patients with Alzheimer's disease (AD). These symptoms are often treated with antipsychotics, usually in an off-label approach. This mini-review provides an updated perspective on the pharmacological approach for the neuropsychiatric symptoms (NPS) in AD. The results of new studies have provided a better understanding of AD-related NPS management, but high-quality evidence still needs to be obtained. Herein, we argue for a more cautious approach to the use of antipsychotics in AD and highlight the importance of exploring alternative treatments for NPS. By doing so, we can ensure that patients with AD receive optimal care that is both effective and safe.

Within subject cross-tissue analyzes of epigenetic clocks in substance use disorder postmortem brain and blood

There is a possible accelerated biological aging in patients with substance use disorders (SUD). The evaluation of epigenetic clocks, which are accurate estimators of biological aging based on DNA methylation changes, has been limited to blood tissue in patients with SUD. Consequently, the impact of biological aging in the brain of individuals with SUD remains unknown. In this study, we evaluated multiple epigenetic clocks (DNAmAge, DNAmAgeHannum, DNAmAgeSkinBlood, DNAmPhenoAge, DNAmGrimAge, and DNAmTL) in individuals with SUD (n = 42), including alcohol (n = 10), opioid (n = 19), and stimulant use disorder (n = 13), and controls (n = 10) in postmortem brain (prefrontal cortex) and blood tissue obtained from the same individuals. We found a higher DNAmPhenoAge (β = 0.191, p-value = 0.0104) and a nominally lower DNAmTL (β = -0.149, p-value = 0.0603) in blood from individuals with SUD compared to controls. SUD subgroup analysis showed a nominally lower brain DNAmTL in subjects with alcohol use disorder, compared to stimulant use disorder and controls (β = 0.0150, p-value = 0.087). Cross-tissue analyzes indicated a lower blood DNAmTL and a higher blood DNAmAge compared to their respective brain values in the SUD group. This study highlights the relevance of tissue specificity in biological aging studies and suggests that peripheral measures of epigenetic clocks in SUD may depend on the specific type of drug used.

Frequency and Pathophysiology of Apathy in Huntington Disease: A Systematic Review and Meta-Analysis

OBJECTIVE

Apathy is a common behavioral symptom of Huntington disease (HD). This systematic review describes current evidence on the pathophysiology, assessment, and frequency of apathy in HD.

METHODS

This systematic review was conducted in accordance with PRISMA guidelines. Using a comprehensive search strategy, the investigators searched the MEDLINE, Embase, and PsycINFO databases. All studies that evaluated apathy in HD patients with a valid scale and reported apathy frequency or scores were included. Apathy scores were analyzed by mean or standardized mean differences in accordance with Cochrane guidelines.

RESULTS

A total of 1,085 records were screened and 80 studies were ultimately included. The Problem Behaviors Assessment-Short was the most frequently used apathy assessment tool. Apathy frequency generally ranged from 10%-33% in premanifest HD to 24%-76% in manifest HD. A meta-analysis of 5,311 records of patients with premanifest HD showed significantly higher apathy scores, with a standardized mean difference of 0.41 (CI=0.29-0.52; p<0.001). A comparison of 1,247 patients showed significantly higher apathy scores in manifest than premanifest HD, with a mean difference of 1.87 (CI=1.48-2.26; p<0.001). There was evidence of involvement of various cortical and subcortical brain regions in HD patients with apathy.

CONCLUSIONS

Apathy was more frequent among individuals with premanifest HD compared with those in a control group and among individuals with manifest HD compared with those with premanifest HD. Considering the complexity and unique pattern of development in neurodegenerative disease, further studies are required to explore the pathophysiology of apathy in HD.

Incidence rate of psychiatric disorders in 2020: The pivotal role played by SARS-CoV-2 infection

Importance

The Coronavirus Disease (COVID-19) pandemic has significantly impacted mental health outcomes. While the frequency of anxiety and depressive symptoms has increased in the whole population, the relationship between COVID-19 and new psychiatric diagnoses remains unclear.

Objective

To compare the population incidence rate of emergence of de novo psychiatric disorders in 2020 compared to the previous years, and to compare the incidence rate of new psychiatric disorder diagnoses between people with vs without COVID-19.

Design, setting, and participants

This study utilized administrative claims data from the Clinformatics® Data Mart database, licensed from Optum®. The study is a cross-sectional analysis that compared the incidence rate of new psychiatric disorders in 2020 vs. 2018 and 2019 in the entire insured population database. Subsequently, the incidence of new psychiatric disorders in people with vs. without COVID-19 during 2020 was analyzed.

Exposure

The exposures included diagnosis and severity of COVID-19 infection.

Main outcomes measures

The dependent variables of interest were the incidence rates of new psychiatric disorders, specifically schizophrenia spectrum disorders, mood disorders, anxiety disorders, and obsessive-compulsive disorder.

Results

The population studied included 10,463,672 US adults (mean age 52.83, 52% female) who were unique people for the year of 2020. Incidence of newly diagnosed psychiatric disorders per 1,000 individuals in the 2020 whole population were 28.81 (CI: 28.71, 28.92) for anxiety disorders, 1.04 (CI: 1.02, 1.06) for schizophrenia disorders, 0.42 (CI: 0.41, 0.43) for OCD and 28.85 (CI: 28.75, 28.95) for mood disorders. These rates were not significantly higher than 2018 or 2019. When comparing incidence rates between COVID-19 vs. non-COVID-19 populations in 2020, the rates were significantly higher in the COVID-19 population: 46.89 (CI: 46.24, 47.53) for anxiety, 49.31 (CI: 48.66, 49.97) for mood disorders, 0.57 (CI: 0.50, 0.65) for OCD, and 3.52 (CI: 3.34, 3.70) for schizophrenia. COVID-19 severity was significantly associated with new diagnoses of schizophrenia, anxiety and mood disorders in multivariate analyses.

Conclusions

Compared to 2018 and 2019, in 2020 there was no increased incidence of new psychiatric disorders in the general population based on insurance claims data. Importantly, people with COVID-19 were more likely to be diagnosed with a new psychiatric disorder, most notably disorders with psychosis, indicating a potential association between COVID-19 and mental/brain health.

Immunopsychiatry: An Update on Autoimmune Encephalitis for Neuropsychiatrists

INTRODUCTION

Autoimmune encephalitis (AIE) is a group of immune-mediated inflammatory processes of the brain with marked psychiatric features. Although relatively rare, they might offer difficult differential diagnosis with psychiatric conditions, especially catatonia and psychotic syndromes. Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is the most common AIE, presenting with psychiatric syndromes in 90% of cases. The associated psychopathology is complex, pleomorphic and best characterized when there is involvement of a psychiatrist in the assessment.

AREAS COVERED

This text will review the main aspects of AIE to psychiatrists and/or neuropsychiatrists.

EXPERT OPINION

Immune system dysfunction has been implicated in the pathophysiology of psychiatric symptoms and disorders. The use of diagnostic criteria of possible AIE, especially when specific antibodies of AIE are not available, allows early diagnosis and prompt treatment which are associated with better clinical outcomes. The study of the psychiatric aspects of AIE can broaden our knowledge of the underlying mechanisms of various psychiatric manifestations.

Factors Associated with Apathy in Alzheimer’s Disease: A Cross-Sectional Analysis of the Texas Alzheimer’s Research and Care Consortium (TARCC) Study

Background: Apathy is among the most frequent neuropsychiatric syndromes in Alzheimer’s disease (AD). Objective: To determine the prevalence of apathy and the associated clinical and laboratorial parameters (focus on inflammatory biomarkers) in patients with dementia enrolled at the Texas Alzheimer’s Research and Care Consortium (TARCC) study. Methods: This is a cross-sectional analysis of TARCC baseline. Participants were evaluated through different clinical tools, including the Mini-Mental State Examination (MMSE) and the Lawton-Brody Instrumental Activities of Daily Life (IADL)/Physical Self-Maintenance Scale (PSMS). Apathy was defined by a positive response to the respective item in the Neuropsychiatric Inventory–Questionnaire applied to caregivers. Serum levels of 16 biomarkers were determined by HumanMap multiplex immunoassay. Comparisons between apathy versus non-apathy groups were carried out with non-parametric tests. Logistic regression and the least absolute shrinkage and selection operator (LASSO) were used to separately model apathy as a function of each biomarker, adjusted for the potential confounders. Results: From 1,319 patients with AD (M/F: 579/740, mean age ± SD: 75.3 ± 8.4), 373 (28.3%) exhibited apathy. When categorized according to the presence of apathy, the groups had significant differences in sex, diabetes diagnosis, and tobacco use. The apathy group also had worse cognitive performance and daily functioning than the non-apathy group as assessed, respectively, by MMSE and IADL/PSMS. Higher levels of interleukin-6, interleukin-10, and leptin were associated with higher odds of apathy. Conclusion: Apathy is associated with cognitive and functional status in AD. The association between apathy and peripheral inflammatory mediators deserves further investigation.

MicroRNA-mRNA networks are dysregulated in opioid use disorder postmortem brain: Further evidence for opioid-induced neurovascular alterations

INTRODUCTION

To understand mechanisms and identify potential targets for intervention in the current crisis of opioid use disorder (OUD), postmortem brains represent an under-utilized resource. To refine previously reported gene signatures of neurobiological alterations in OUD from the dorsolateral prefrontal cortex (Brodmann Area 9, BA9), we explored the role of microRNAs (miRNA) as powerful epigenetic regulators of gene function.

METHODS

Building on the growing appreciation that miRNAs can cross the blood-brain barrier, we carried out miRNA profiling in same-subject postmortem samples from BA9 and blood tissues.

RESULTS

miRNA-mRNA network analysis showed that even though miRNAs identified in BA9 and blood were fairly distinct, their target genes and corresponding enriched pathways overlapped strongly. Among the dominant enriched biological processes were tissue development and morphogenesis, and MAPK signaling pathways. These findings point to robust, redundant, and systemic opioid-induced miRNA dysregulation with a potential functional impact on transcriptomic changes. Further, using correlation network analysis, we identified cell-type specific miRNA targets, specifically in astrocytes, neurons, and endothelial cells, associated with OUD transcriptomic dysregulation. Finally, leveraging a collection of control brain transcriptomes from the Genotype-Tissue Expression (GTEx) project, we identified a correlation of OUD miRNA targets with TGF beta, hypoxia, angiogenesis, coagulation, immune system, and inflammatory pathways.

DISCUSSION

These findings support previous reports of neurovascular and immune system alterations as a consequence of opioid abuse and shed new light on miRNA network regulators of cellular response to opioid drugs.

Episodic memory for emotional and neutral pictures in Parkinson's disease

OBJECTIVE

Prior studies have shown that individuals with Parkinson's disease (PD) exhibit deficits in the processing of emotional information. Here, we investigated whether such deficits caused by PD reduce the mnemonic benefits typically produced by emotion in healthy individuals.

METHOD

Thirty individuals with PD and 30 healthy individuals, matched for sex, age, and education, were recruited for the study. To assess their memory for emotional information, we asked them to observe a series of negative, positive, and neutral images distributed in three consecutive blocks. After a short interval, all observed images were presented again intermixed with new images, and the participants were asked to judge whether each image was "old" or "new" (i.e., recognition test), and to indicate the block in which each image was studied (i.e., source memory test). In addition, to characterize the sample, all participants responded to a series of neuropsychological and psychopathological tests.

RESULTS

As expected, individuals with PD exhibited diminished overall recognition and source memory scores relative to healthy controls (ηp² = 0.16 and 0.14, respectively). More importantly, while healthy controls showed greater recognition accuracy for negative versus neutral images (d = 0.65), this advantage was absent for PD participants (d < 0.18), a null effect corroborated by Bayesian analysis (BF01 = 3.34).

CONCLUSION

The current findings suggest that individuals with PD lack the mnemonic advantage for negative pictures shown by healthy individuals, a deficit that may result from their difficulties in the processing of emotional information. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

ILAE clinical practice recommendations for the medical treatment of depression in adults with epilepsy

The aim of this document is to provide evidence-based recommendations for the medical treatment of depression in adults with epilepsy. The working group consisted of members of an ad hoc Task Force of the International League Against Epilepsy (ILAE) Commission on Psychiatry, ILAE Executive and the International Bureau for Epilepsy (IBE) representatives. The development of these recommendations is based on a systematic review of studies on the treatment of depression in adults with epilepsy, and a formal adaptation process of existing guidelines and recommendations of treatment of depression outside epilepsy using the ADAPTE process. The systematic review identified 11 studies on drug treatments (788 participants, class of evidence III and IV); 13 studies on psychological treatments (998 participants, class of evidence II, III and IV); and 2 studies comparing sertraline with cognitive behavioral therapy (CBT; 155 participants, class of evidence I and IV). The ADAPTE process identified the World Federation of Societies of Biological Psychiatry guidelines for the biological treatment of unipolar depression as the starting point for the adaptation process. This document focuses on first-line drug treatment, inadequate response to first-line antidepressant treatment, and duration of such treatment and augmentation strategies within the broader context of electroconvulsive therapy, psychological, and other treatments. For mild depressive episodes, psychological interventions are first-line treatments, and where medication is used, selective serotonin reuptake inhibitors (SSRIs) are first-choice medications (Level B). SSRIs remain the first-choice medications (Level B) for moderate to severe depressive episodes; however, in patients who are partially or non-responding to first-line treatment, switching to venlafaxine appears legitimate (Level C). Antidepressant treatment should be maintained for at least 6 months following remission from a first depressive episode but it should be prolonged to 9 months in patients with a history of previous episodes and should continue even longer in severe depression or in cases of residual symptomatology until such symptoms have subsided.

How physical activity behavior affected well-being, anxiety and sleep quality during COVID-19 restrictions in Iran

OBJECTIVE

The Islamic Republic of Iran has displayed one of the highest rates of COVID-19 infection in the world and the highest rate of mortality in the Middle East. Iran has used a stringent package of preventive health measures to mitigate the spread of infection, which however has negatively affected individuals' physical and psychological health. This study aimed at examining whether physical-activity (PA) behavior, anxiety, well-being, and sleep-quality changed in response to the COVID-19-related public health restrictions enforced in Iran.

PATIENTS AND METHODS

An online questionnaire was disseminated to adults residing in Iran from November 17, 2020, to February 13, 2021 (~88 days), during Iran's strictest public health restrictions. Main outcome measures included Godin-Shephard Leisure-Time Exercise Questionnaire, General Anxiety Disorder-7, Mental Health Continuum-Short Form, and Pittsburgh Sleep Quality Index.

RESULTS

A total of 3,323 adults (mean age 30±11 years, 54.3% female) participated in the survey. Firstly, the restrictions generally reduced PA behavior: (a) among inactive participants (IPs), 60.6% became less active vs. 5.1% who became more active; and (b) among active participants (APs), 49.9% became less active vs. 22.8% who became more active. Secondly, PA behavior was associated with higher well-being and sleep quality during the restrictions: (a) APs reported higher (or lower) levels of well-being and sleep quality (or anxiety) than did IPs; and (b) among IPs as well as among APs, the more active the participants, the greater (or lower) the levels of well-being and sleep quality (or anxiety).

CONCLUSIONS

This study showed the beneficial role of PA behavior for well-being, anxiety, and sleep quality during the COVID-19 restrictions, whereas such restrictions appeared to decrease PA participation. Active lifestyle should be then encouraged during the COVID-19 outbreak while taking precautions.

Changes in Brain-derived Neurotrophic Factor From Active and Sham Transcranial Direct Current Stimulation in Older Adults With Knee Osteoarthritis

OBJECTIVES

Previous work has shown effects of transcranial direct current stimulation (tDCS) on clinical pain measures, qualitative sensory testing measures, and peripheral inflammation. The present report extends this research to investigate the effect of tDCS on brain-derived neurotrophic factor (BDNF) levels.

MATERIALS AND METHODS

This secondary analysis examined a sample of 40 older adults (50 to 70 y old) with symptomatic knee osteoarthritis randomly assigned in a 1:1 fashion to active (n=20) or sham (n=20) tDCS for 20 minutes on 5 consecutive days. BDNF was measured before the first session and after the final treatment session. Generalized linear modeling evaluated BDNF plasma levels as a function of tDCS group, adjusted for baseline. Bayesian statistical inference was used to quantify the probability that effects of the treatment exist.

RESULTS

Generalized linear modeling indicated a 90.4% posterior probability that the sham condition had 49.9% higher BDNF at the end of treatment, controlling for baseline. Follow-up analyses within the active TDCS group supported an association between change in BDNF and change in clinical pain, and exploratory analyses found an effect of tDCS on irisin.

DISCUSSION

Results indicated that tDCS could be a potential nonpharmacological treatment to decrease BDNF levels, which may in turn decrease pain. This study adds to a growing literature suggesting that tDCS affects cortical excitability, and consequentially, the neural circuits implicated in pain modulation. In addition to a direct connection to analgesia, BDNF changes may reflect tDCS-induced changes in different cortical areas and/or neural circuits.

Apathy is not associated with a panel of biomarkers in older adults with HIV disease

OBJECTIVE

Apathy is prevalent in HIV disease and can significantly impact personal well-being; however, little is known about its neurobiological substrates in persons with HIV (PWH) disease.

METHODS

This cross-sectional, correlational study examined the association between apathy and several plasma biomarkers (tumor necrosis factor alpha, kynurenine, tryptophan, quinolinic acid, brain-derived neurotrophic factor, glial fibrillary acidic protein, neurofilament light chain, and phosphorylated tau at position threonine 181) in 109 PWH and 30 seronegative participants ages 50 and older. Apathy was measured with a composite score derived from subscales of the Frontal Systems Behavior Scale and the Profile of Mood States.

RESULTS

Multiple regressions showed that PWH had significantly greater severity of apathy symptoms, independent of both data-driven and conceptually-based covariates. Pairwise correlations in the PWH sample indicated that apathy was not significantly associated with any of the measured biomarkers and all of the effect sizes were small.

CONCLUSION

Findings suggest that apathy is not strongly associated with peripheral biomarkers of inflammation, neurotrophic support, or neurodegeneration in older PWH. Limitations of this study include the cross-sectional design, the use of self-report measures of apathy, and low rates of viremia. Longitudinal studies in more representative samples of PWH that include a more comprehensive panel of fluid biomarkers, informant and behavioral indicators of apathy, and relevant psychosocial factors might help to further clarify the neurobiological substrates of this complex neuropsychiatric phenomenon.

Analysis of COVID-19 Infection and Mortality Among Patients With Psychiatric Disorders, 2020

IMPORTANCE

People with major psychiatric disorders are more likely to have comorbidities associated with worse outcomes of COVID-19. This fact alone could determine greater vulnerability of people with major psychiatric disorders to COVID-19.

OBJECTIVE

To assess the odds of testing positive for and mortality from COVID-19 among and between patients with schizophrenia, mood disorders, anxiety disorders and a reference group in a large national database.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used an electronic health record data set aggregated from many national sources in the United States and licensed from Optum with current and historical data on patients tested for COVID-19 in 2020. Three psychiatric cohorts (patients with schizophrenia, mood disorders, or anxiety disorders) were compared with a reference group with no major psychiatric conditions. Statistical analysis was performed from March to April 2021.

EXPOSURE

The exposures observed include lab-confirmed positivity for COVID-19 and mortality.

MAIN OUTCOMES AND MEASURES

The odds of testing positive for COVID-19 in 2020 and the odds of death from COVID-19 were measured.

RESULTS

The population studied included 2 535 098 unique persons, 3350 with schizophrenia, 26 610 with mood disorders, and 18 550 with anxiety disorders. The mean (SD) age was 44 (23) years; 233 519 were non-Hispanic African American, 1 583 440 were non-Hispanic Caucasian; and 1 580 703 (62%) were female. The schizophrenia cohort (positivity rate: 9.86%; adjusted OR, 0.90 [95% CI, 0.84-0.97]) and the mood disorder cohort (positivity rate: 9.86%; adjusted OR, 0.93 [95% CI, 0.87-0.99]) had a significantly lower rate of positivity than the anxiety disorder cohort (positivity rate: 11.17%; adjusted OR, 1.05 [95% CI, 0.98-1.12) which was closer to the reference group (11.91%). After fully adjusting for demographic factors and comorbid conditions, patients with schizophrenia were nearly 4 times more likely to die from the disease than the reference group (OR, 3.74; 95% CI, 2.66-5.24). The mood disorders COVID-19 cohort had a 2.76 times greater odds of mortality than the reference group (OR, 2.76; 95% CI, 2.00-3.81), and the anxiety disorders cohort had a 2.39 times greater odds of mortality than the reference group (OR, 2.39; 95% CI, 1.68-3.27).

CONCLUSIONS AND RELEVANCE

By examining a large database while controlling for multiple confounding factors such as age, race and ethnicity, and comorbid medical conditions, the present study found that patients with schizophrenia had much increased odds of mortality by COVID-19.

Multidimensional Approach Assessing the Role of Interleukin 1 Beta in Mesial Temporal Lobe Epilepsy

We aimed to investigate the role of interleukin-1 beta (IL-1β) in the mechanisms underlying mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE+HS). We assessed a cohort of 194 patients with MTLE+HS and 199 healthy controls. Patients were divided into those with positive and negative antecedent febrile seizures (FS). We used a multidimensional approach, including (i) genetic association with single nucleotide polymorphisms (SNPs) in the IL1B gene; (ii) quantification of the IL1B transcript in the hippocampal tissue of patients with refractory seizures; and (iii) quantification of the IL-1β protein in the plasma. We found a genetic association signal for two SNPs, rs2708928 and rs3730364^*C in the IL1B gene, regardless of the presence of FS (adjusted p = 9.62e–11 and 5.14e–07, respectively). We found no difference between IL1B transcript levels when comparing sclerotic hippocampal tissue from patients with MTLE+HS, without FS, and hippocampi from autopsy controls (p > 0.05). Nevertheless, we found increased IL-1β in the plasma of patients with MTLE+HS with FS compared with controls (p = 0.0195). Our results support the hypothesis of a genetic association between MTLE+HS and the IL1B gene

Sydenham's chorea: from pathophysiology to therapeutics

Sydenham's chorea is an autoimmune chorea emerging after a group A beta-hemolytic streptococcal (GABHS) infection, i.e. a rheumatic chorea with or without the presence of carditis or arthritis. The disorder, defined by the presence of chorea, is also associated with cognitive and behavioral symptoms, including emotional lability, anxiety, depressive and obsessive-compulsive symptoms. The authors review the pathophysiology, clinical characteristics, and available evidence on therapeutic strategies, the latter including the secondary prevention of GABHS infections, reduction of chorea, and immune modulation. Sydenham's chorea has been regarded as a model for pediatric autoimmune neuropsychiatric disorders, however, the field is marked by conflicting results and controversies. Regarding therapeutics, there are limited high-quality interventional studies and the selection of treatment strategy often relies on the clinician's experience. A serial treatment algorithm is presented based upon the severity of clinical presentation and response to symptomatic pharmacotherapy.

Inflammatory and neurotrophic factor plasma levels are related to epilepsy independently of etiology

OBJECTIVE

Inflammation plays an essential role in epilepsy. Studies indicate that cytokines and neurotrophic factors can act in neuroexcitability and epileptogenesis. We aimed to investigate the association between plasma inflammatory and neurotrophic markers, seizure frequency, and chronic epilepsy subtypes.

METHODS

We studied 446 patients with epilepsy and 166 healthy controls. We classified patients according to etiology and seizure frequency. We measured plasma levels of interleukin-1 (IL-1), IL-2, IL-4, IL-6, IL-10, IL-17, interferon-γ (IFNγ), tumor necrosis factor α (TNFα), soluble TNF receptor 1 (sTNFr1), sTNFr2, brain-derived neurotrophic factor (BDNF), neurotrophic factor 3 (NT3), NT4/5, ciliary neurotrophic factor (CNTF), nerve growth factor (NGF), and glial cell line-derived neurotrophic factor (GDNF) by enzyme-linked immunosorbent assay or cytometric bead array.

RESULTS

The plasma levels of BDNF, NT3, NGF, and sTNFr2 were higher, whereas IL-2, IL-4, IL-6, IL-10, IL-17, IFNγ, TNFα, CNTF, and sTNFr1 were lower in patients than controls. IL1, GDNF, and NT4/5 were similar between groups. These markers did not correlate with age, sex, and epilepsy duration. The molecule sTNFr2 was the best marker to discriminate patients from controls (area under the curve = .857), also differing between patients with frequent and infrequent seizures.

SIGNIFICANCE

This large cohort confirmed that patients with epilepsy have abnormal levels of plasma inflammatory and neurotrophic markers independent of the underlying etiology. Plasma level of sTNFr2 was related to seizure frequency and discriminated people with or without epilepsy with good accuracy, making it a potential biomarker for epilepsy and seizure burden.

Cannabinoid receptor gene polymorphisms and cognitive performance in patients with schizophrenia and controls

Objective:

To test the hypothesis that genetic variations of cannabinoid receptors contribute to the pathophysiology of cognitive deficits in schizophrenia.

Methods:

In this genetic association case-control study, cannabinoid receptor polymorphisms CNR1 rs12720071 and CNR2 rs2229579 were tested for association with neurocognitive performance in 69 patients with schizophrenia and 45 healthy controls. Neurocognition was assessed by the Brief Assessment of Cognition in Schizophrenia (BACS).

Results:

We found a consistent association between CNR1 rs12720071 polymorphism and the cognitive performance of patients in several cognitive domains. Patients with C/C polymorphism presented significantly worse performance in motor speed, verbal fluency, attention/processing speed and reasoning/problem solving.

Conclusion:

Although limited, our data support the hypothesis that CNR1 variations may be associated with the pathogenesis of cognitive deficits of schizophrenia.

The Relationship Between Plasma Oxytocin and Executive Functioning in Huntington's Disease: A Pilot Study

The role of oxytocin (OT) in social cognition of patients with Huntington's disease (HD) has been studied, but its impact on executive functioning has not been explored yet. Healthy controls, premanifest HD, and manifest HD participants underwent executive functioning assessment and OT plasma measurement. There were no significant group differences in plasma OT levels. Higher OT levels were associated with better executive functioning in premanifest HD participants. Our findings revealed an association between OT levels and depressive symptoms in premanifest and manifest HD participants. The potential role of OT in HD deserves further investigation.

Association of Vitamin D Levels with Incident All-Cause Dementia in Longitudinal Observational Studies: A Systematic Review and Meta-analysis

BACKGROUND

The role of vitamin D is not only limited to bone health and pathogenesis of chronic diseases. Evidence now suggests that it is also involved in the development of various dementias and Alzheimer's disease (AD).

OBJECTIVE

To carry out a systematic review and meta-analysis to evaluate the association between vitamin D levels and increased risk of incident all-cause dementia in longitudinal studies.

DESIGN

We conducted a systematic review and meta-analysis using the electronic bibliographic databases PubMed and Scopus.

SETTING

Prospective cohort studies.

PARTICIPANTS

Community-dwelling older adults.

MEASUREMENTS

Vitamin D serum concentrations were categorized in three groups: normal levels (>50 nmol/L), insufficient levels (25 - 49.9 nmol/L), and deficient levels (<25 nmol/L). We performed a meta-analysis using the general inverse variance method to calculate the pooled risk of AD and all-cause dementia according to vitamin D levels. Random-effects or fixed-effect model were used to calculate the pooled risk based on the heterogeneity analysis.

RESULTS

Five studies were included in the meta-analysis. The pooled risk of all-cause dementia and AD was significantly higher in those with deficient serum vitamin D level compared to those with normal level (1.33, CI95% [1.15, 1.54], and 1.87, CI95% [1.03, 3.41], respectively). Those with insufficient level also had a higher pooled risk of all-cause dementia and AD, but the strength of association was less robust (1.14 CI95% [1.02, 1.27] and 1.25, CI95% [1.04 - 1.51], respectively).

CONCLUSION

We found a gradient effect for the risk of all-cause dementia and AD according to the vitamin D level, with higher risk in those in the deficient levels group and intermediate risk in those with insufficient levels. Our findings were limited by the relatively small number of studies included in the meta-analysis and their geographic restriction.

The Relationship Between Plasma BDNF and Pain in Older Adults With Knee Osteoarthritis

Osteoarthritis (OA) is the most prevalent cause of chronic pain and disability in people aged ≥45 years, with the knee being the most affected joint. Neurotrophic factors like brain-derived neurotrophic factor (BDNF), which promotes neurogenesis and neuroplasticity, have been shown to significantly affect chronic pain. This study aimed to investigate the relationship between resting plasma BDNF levels and clinical pain and quantitative sensory testing measures in older adults with knee OA pain. For this secondary analysis, a previously reported dataset was used comprised of older adults with knee OA who underwent quantitative sensory testing. A comprehensive generalized linear model (GLM) was built to understand the relationships between BDNF and important covariates, followed by the elastic net (EN) method for variable selection. GLM was then performed to regress BDNF levels against only the variables selected by EN. The mean age of the sample was 60.4 years (SD = 9.1). Approximately half of the participants were female (53%). Plasma BDNF levels were positively associated with heat pain threshold and the numeric rating scale of pain. Future mechanistic studies are needed to replicate and extend these findings to advance our knowledge of the underlying mechanisms of BDNF in knee OA and other chronic pain conditions.

Pro-inflammatory interleukin-6 signaling links cognitive impairments and peripheral metabolic alterations in Alzheimer's disease

Alzheimer's disease (AD) is associated with memory impairment and altered peripheral metabolism. Mounting evidence indicates that abnormal signaling in a brain-periphery metabolic axis plays a role in AD pathophysiology. The activation of pro-inflammatory pathways in the brain, including the interleukin-6 (IL-6) pathway, comprises a potential point of convergence between memory dysfunction and metabolic alterations in AD that remains to be better explored. Using T2-weighted magnetic resonance imaging (MRI), we observed signs of probable inflammation in the hypothalamus and in the hippocampus of AD patients when compared to cognitively healthy control subjects. Pathological examination of post-mortem AD hypothalamus revealed the presence of hyperphosphorylated tau and tangle-like structures, as well as parenchymal and vascular amyloid deposits surrounded by astrocytes. T2 hyperintensities on MRI positively correlated with plasma IL-6, and both correlated inversely with cognitive performance and hypothalamic/hippocampal volumes in AD patients. Increased IL-6 and suppressor of cytokine signaling 3 (SOCS3) were observed in post-mortem AD brains. Moreover, activation of the IL-6 pathway was observed in the hypothalamus and hippocampus of AD mice. Neutralization of IL-6 and inhibition of the signal transducer and activator of transcription 3 (STAT3) signaling in the brains of AD mouse models alleviated memory impairment and peripheral glucose intolerance, and normalized plasma IL-6 levels. Collectively, these results point to IL-6 as a link between cognitive impairment and peripheral metabolic alterations in AD. Targeting pro-inflammatory IL-6 signaling may be a strategy to alleviate memory impairment and metabolic alterations in the disease.

Microglia Activation in Basal Ganglia Is a Late Event in Huntington Disease Pathophysiology

OBJECTIVE

To define the role played by microglia in different stages of Huntington disease (HD), we used the TSPO radioligand [11C]-ER176 and PET to evaluate microglial activation in relation to neurodegeneration and in relation to the clinical features seen at premanifest and manifest stages of the disease.

METHODS

This is a cross-sectional study in which 18 subjects (6 controls, 6 premanifest, and 6 manifest HD gene carriers) underwent a [11C]-ER176 PET scan and an MRI for anatomic localization. Segmentation of regions of interest (ROIs) was performed, and group differences in [11C]-ER176 binding (used to evaluate the extent of microglial activation) were assessed by the standardized uptake value ratio (SUVR). Microglial activation was correlated with ROIs volumes, disease burden, and the scores obtained in the clinical scales. As an exploratory aim, we evaluated the dynamic functions of microglia in vitro, by using induced microglia-like (iMG) cells from peripheral blood monocytes.

RESULTS

Individuals with manifest HD present higher [11C]-ER176 SUVR in both globi pallidi and putamina in comparison with controls. No differences were observed when we compared premanifest HD with controls or with manifest HD. We also found a significant correlation between increased microglial activation and cumulative disease burden, and with reduced volumes. iMG from controls, premanifest HD, and manifest HD patients showed similar phagocytic capacity.

CONCLUSIONS

Altogether, our data demonstrate that microglial activation is involved in HD pathophysiology and is associated with disease progression.