Recent advances in HIV-associated neurocognitive disorders: a focus on older adults and sub-Saharan Africa.

PURPOSE OF REVIEW: We reviewed recent literature on prevalence and interventional approaches for cognitive impairment in the context of HIV infection alongside current controversies and challenges around its nomenclature, screening, and diagnosis. RECENT FINDINGS: Prevalence estimates for HIV-associated neurocognitive disorder (HAND) indicate that HAND remains highly prevalent despite combination antiretroviral treatment (cART) widely used. The available data are heterogeneous, particularly in sub-Saharan Africa (SSA) where recent reviews indicate substantial heterogeneity, wide prevalence estimates and lack of data from the majority SSA countries, despite them currently experiencing the greatest burden worldwide of both HIV and HAND.Several alternative approaches to diagnosis and classification of cognitive impairment in HIV have been published, taking into account changing clinical phenotypes. SUMMARY: Cognitive impairment remains a significant challenge in the care of people living with HIV despite advances in treatment. Ongoing controversies exist around nomenclature and classification, screening measures, and the phenotype and aetiology of observed impairments. Two current areas of research priority and focus include understanding current phenotypes of individuals living and ageing with treated HIV and differing levels of risk for HAND in these phenotypes, alongside the effects of commonly occurring comorbidities.The current evidence base for interventional approaches is limited, but growing. The most promising avenues appear to be multidisciplinary. These are currently focussed on high income settings rather than SSA where the majority of people living with HIV, and affected by cognitive impairment in the context of HIV, currently reside.

Caspase cleavage of gasdermin E causes neuronal pyroptosis in HIV-associated neurocognitive disorder.

Despite effective antiretroviral therapies, 20-30% of persons with treated HIV infection develop a neurodegenerative syndrome termed HIV-associated neurocognitive disorder (HAND). HAND is driven by HIV expression coupled with inflammation in the brain but the mechanisms underlying neuronal damage and death are uncertain. The inflammasome-pyroptosis axis coordinates an inflammatory type of regulated lytic cell death that is underpinned by the caspase-activated pore-forming gasdermin proteins. The mechanisms driving neuronal pyroptosis were investigated herein in models of HAND, using multi-platform molecular and morphological approaches that included brain tissues from persons with HAND and simian immunodeficiency virus (SIV)-infected non-human primates as well as cultured human neurons. Neurons in the frontal cortices from persons with HAND showed increased cleaved gasdermin E (GSDME), which was associated with ß-III tubulin degradation and increased HIV levels. Exposure of cultured human neurons to the HIV-encoded viral protein R (Vpr) elicited time-dependent cleavage of GSDME and Ninjurin-1 (NINJ1) induction with associated cell lysis that was inhibited by siRNA suppression of both proteins. Upstream of GSDME cleavage, Vpr exposure resulted in activation of caspases-1 and 3. Pretreatment of Vpr-exposed neurons with the caspase-1 inhibitor, VX-765, reduced cleavage of both caspase-3 and GSDME, resulting in diminished cell death. To validate these findings, we examined frontal cortical tissues from SIV-infected macaques, disclosing increased expression of GSDME and NINJ1 in cortical neurons, which was co-localized with caspase-3 detection in animals with neurological disease. Thus, HIV infection of the brain triggers the convergent activation of caspases-1 and -3, which results in GSDME-mediated neuronal pyroptosis in persons with HAND. These findings demonstrate a novel mechanism by which a viral infection causes pyroptotic death in neurons while also offering new diagnostic and therapeutic strategies for HAND and other neurodegenerative disorders.

Association between anaesthesia-related factors and postoperative neurocognitive disorder: a post-hoc analysis.

BACKGROUND: Postoperative neurocognitive disorder (pNCD) is common after surgery. Exposure to anaesthetic drugs has been implicated as a potential cause of pNCD. Although several studies have investigated risk factors for the development of cognitive impairment in the early postoperative phase, risk factors for pNCD at 3 months have been less well studied. The aim of this study was to identify potential anaesthesia-related risk factors for pNCD at 3 months after surgery. METHODS: We analysed data obtained for a prospective observational study in patients aged ≥ 65 years who underwent surgery for excision of a solid tumour. Cognitive function was assessed preoperatively and at 3 months postoperatively using 5 neuropsychological tests. Postoperative NCD was defined as a postoperative decline of ≥ 25% relative to baseline in ≥ 2 tests. The association between anaesthesia-related factors (type of anaesthesia, duration of anaesthesia, agents used for induction and maintenance of anaesthesia and analgesia, the use of additional vasoactive medication, depth of anaesthesia [bispectral index] and mean arterial pressure) and pNCD was analysed using logistic regression analyses. Furthermore, the relation between anaesthesia-related factors and change in cognitive test scores expressed as a continuous variable was analysed using a z-score. RESULTS: Of the 196 included patients, 23 (12%) fulfilled the criteria for pNCD at 3 months postoperatively. A low preoperative score on Mini-Mental State Examination (OR, 8.9 [95% CI, (2.8-27.9)], p < 0.001) and a longer duration of anaesthesia (OR, 1.003 [95% CI, (1.001-1.005)], p = 0.013) were identified as risk factors for pNCD. On average, patients scored higher on postoperative tests (mean z-score 2.35[± 3.13]). CONCLUSION: In this cohort, duration of anaesthesia, which is probably an expression of the complexity of the surgery, was the only anaesthesia-related predictor of pNCD. On average, patients' scores on cognitive tests improved postoperatively.

HIV-related neurocognitive disorders: Diagnosis, Treatment, and Mental Health Implications: A Review.

HIV-related neurocognitive disorders (HAND) have emerged as a significant concern in the context of HIV infection. This article provides a comprehensive overview of the diagnosis, treatment, and mental health implications associated with HAND. Diagnosis of HAND involves a multifaceted approach, combining clinical assessments, neurocognitive testing, and neuroimaging techniques. Various screening tools and standardized assessments have been developed to aid in the early detection and monitoring of HAND. Timely diagnosis allows for appropriate interventions and personalized treatment strategies. Treatment for HAND encompasses a multidisciplinary approach targeting different aspects of cognitive impairment. Antiretroviral therapy (ART) remains the cornerstone of treatment, effectively reducing viral load and preventing further neurocognitive decline. Adjunctive therapies, including cognitive rehabilitation, pharmacological interventions, and psychosocial support, play crucial roles in managing cognitive symptoms and enhancing overall quality of life. Mental health implications associated with HAND are profound and require special attention. Individuals with HAND are at higher risk of experiencing psychological distress, depression, anxiety, and reduced social functioning. Integrated care models that address physical and mental health aspects are vital in optimizing treatment outcomes and promoting mental well-being in this population. Furthermore, this paper highlights the need for ongoing research to unravel the underlying mechanisms of HAND and develop targeted interventions. Identifying risk factors, understanding the impact of HIV on the brain, and exploring novel treatment modalities are essential areas of focus. Additionally, living with HAND social and cultural aspects must be considered to ensure equitable access to care and support for all affected individuals.

Systemic inflammation, neuroinflammation and perioperative neurocognitive disorders.

Perioperative neurocognitive disorder (PND) is a common disorder following anesthesia and surgery, especially in the elderly. The complex cellular and molecular processes are involved in PND, but the underlying pathogenesis of which remains inconclusive due to conflicting data. A growing body of evidence has been shown that perioperative systemic inflammation plays important roles in the development of PND. We reviewed the relevant literature retrieved by a search in the PubMed database (on July 20, 2023). The search terms used were "delirium", "post operative cognitive dysfunction", "perioperative neurocognitive disorder", "inflammation" and "systemic", alone and in combination. All articles identified were English-language, full-text papers. The ones cited in the review are those that make a substantial contribution to the knowledge about systemic inflammation and PNDs. The aim of this review is to bring together the latest evidence for the understanding of how perioperative systemic inflammation mediates neuroinflammation and brain injury, how the inflammation is regulated and how we can translate these findings into prevention and/or treatment for PND.

Genomic Factors and Therapeutic Approaches in HIV-Associated Neurocognitive Disorders: A Comprehensive Review.

HIV-associated neurocognitive disorders (HANDs) still persist despite improved life expectancy, reduced viral loads, and decreased infection severity. The number of patients affected by HANDs ranges from (30 to 50) % of HIV-infected individuals. The pathological mechanisms contributing to HANDs and the most serious manifestation of the disease, HIV-associated dementia (HAD), are not yet well understood. Evidence suggests that these mechanisms are likely multifactorial, producing neurocognitive complications involving disorders such as neurogenesis, autophagy, neuroinflammation, and mitochondrial dysfunction. Over the years, multiple pharmacological approaches with specific mechanisms of action acting upon distinct targets have been approved. Although these therapies are effective in reducing viral loading to undetectable levels, they also present some disadvantages such as common side effects, the need for administration with a very high frequency, and the possibility of drug resistance. Genetic studies on HANDs provide insights into the biological pathways and mechanisms that contribute to cognitive impairment in people living with HIV-1. Furthermore, they also help identify genetic variants that increase susceptibility to HANDs and can be used to tailor treatment approaches for HIV-1 patients. Identification of the genetic markers associated with disease progression can help clinicians predict which individuals require more aggressive management and by understanding the genetic basis of the disorder, it will be possible to develop targeted therapies to mitigate cognitive impairment. The main goal of this review is to provide details on the epidemiological data currently available and to summarise the genetic (specifically, the genetic makeup of the immune system), transcriptomic, and epigenetic studies available on HANDs to date. In addition, we address the potential pharmacological therapeutic strategies currently being investigated. This will provide valuable information that can guide clinical care, drug development, and our overall understanding of these diseases.

Perioperative neurocognitive disorders.

Perioperative neurocognitive disorders are a group of conditions characterised by changes in cognitive function, which affect older people after surgery and anaesthesia. Multicomponent interventions may reduce the impact of perioperative neurocognitive disorders on patients and healthcare systems.

[Gradual approach for the etiological diagnosis of the neurocognitive disorder]. / Approche graduelle pour le diagnostic étiologique des troubles neurocognitifs.

Neurocognitive disorders (TNC) are of a public health concern. An early and accurate diagnosis is important to tailor a personalised care. We illustrate the importance of a graduated etiological diagnostic approach centered on the clinical presentation employing the case of a patient with a progressive neurovisual disorder suggestive of a common form of Alzheimer's disease. The results of the CSF biomarkers analysis argue against this diagnosis and justifies seeking a Lewy body disease as a differential diagnosis even if all the clinical criteria are initially incomplete. In this article, we illustrate the progressive and graduated approach in the use of complementary medical tests available for reliable and early diagnosis in order to optimise the care plan and predict clinical progress and needs.

Les troubles neurocognitifs (TNC) sont un enjeu de santé publique. Un diagnostic précoce et précis est important pour une prise en charge personnalisée. Nous illustrons l'intérêt d'une démarche diagnostique étiologique graduelle centrée sur la clinique à partir du cas d'un patient atteint d'un trouble neurovisuel progressif suggérant une forme commune de maladie d'Alzheimer. L'analyse des biomarqueurs du LCR argumente en défaveur de ce diagnostic et justifie de rechercher comme diagnostic différentiel une maladie à corps de Lewy même si l'ensemble des critères cliniques sont initialement incomplets. Nous discutons dans cet article la démarche progressive et graduelle dans l'emploi des examens complémentaires à disposition pour un diagnostic fiable et précoce afin d'optimiser le plan de soins et de prédire l'évolution clinique et les besoins.

Analysis of the 2007-2018 National Health Interview Survey (NHIS): Examining Neurological Complications among Children with Sickle Cell Disease in the United States.

This study compared neurological complications among a national sample of United States children with or without sickle cell disease (SCD) and evaluated health status, healthcare and special education utilization patterns, barriers to care, and association of SCD status and demographics/socioeconomic status (SES) on comorbidities and healthcare utilization. Data was acquired from the National Health Interview Survey (NHIS) Sample Child Core questionnaire 2007-2018 dataset that included 133,542 children. An affirmation from the guardian of the child determined the presence of SCD. Regression analysis was used to compare the associations between SCD and demographics/SES on neurological conditions at p < 0.05. Furthermore, adjusted odds ratios (AORs) were estimated for having various neurological conditions. Of the 133,481 children included in the NHIS, the mean age was 8.5 years (SD: 0.02) and 215 had SCD. Of the children with SCD, the sample composition included male (n = 110), and Black (n = 82%). The SCD sample had higher odds of having neuro-developmental conditions (p < 0.1). Families of Black children (55% weighted) reported household incomes < 100% of federal poverty level. Black children were more likely to experience longer wait times to see the doctor (AOR, 0.3; CI 0.1-1.1). Compared to children without SCD, those with SCD had a greater chance of seeing a medical specialist within 12 months (AOR 2.3; CI 1.5-3.7). This representative sample of US children with SCD shows higher odds of developing neurological complications, increased healthcare and special education services utilization, with Black children experiencing a disproportionate burden. This creates the urgency to address the health burden for children with SCD by implementing interventions in healthcare and increasing education assistance programs to combat neurocognitive impairments, especially among Black children.

Neurocognitive Disorders in HIV-positive Patients.

Human immunodeficiency viruses (HIV) associated neurocognitive disorders (HAND) encompasses a group of syndromes of various degrees of impairment in cognition and daily functioning of HIV positive individuals. Although the widespread use of highly active antiretroviral therapy (HAART) has drastically reduced the prevalence of severe form of HAND, like HIV associated dementia (HAD), the prevalence of HAND and associated morbidity remains high. OBJECTIVES: (1) To know the prevalence of HAND in HIV-infected patients of a multi-ethnic population. (2) To describe various types of neurocognitive impairment among patients of HAND and study the factors affecting HAND. STUDY DESIGN: This study was a cross-sectional descriptive study conducted on 250 HIV-positive patients in outpatient department (OPD) of a tertiary care center in Mumbai, conducted over a period of 12 months. Patients with HIV-1 attending the OPD and having a minimal formal education of 4 years were included. Patients with concomitant delirium, any known central nervous system (CNS) disorder, any psychiatric disorder, and pregnant females were excluded. Outcome measures-the test batteries used were (1) International HIV Dementia Scale (IHDS) and (2) Addenbrookes cognitive examination-revised (ACE-R) scale. RESULTS: Of 250 subjects studied, 55.6% (139) were males and 44.4 % (111) were females. The mean age of study population was 39.42 years. The mean years of education were 8.32 years. The mean duration of infection (diagnosis of HIV-positive state) was 64.49 months and the mean duration of HAART intake in our patients was 52.30 months. The mean cluster of differentiation 4 (CD4) counts of our subjects were 527.13 per cumm [standard deviation (SD) of 234.13]. The mean nadir CD4 counts were 224.35 per cumm (SD of 115.09). Using the ACE-R scale, the prevalence of HAND was 71.60%, of which 37.20% had an asymptomatic neurological impairment, 29.60% had mild cognitive dysfunction, and 4.80% had HAD. Memory, verbal fluency and visuospatial abilities were the most affected domains on the ACE-R and memory recall and psychomotor speed were affected more on the IHDS. The prevalence of HAND was more with increasing age (p = 0.020), lesser education (p < 0.00) and lesser nadir CD4 counts (p < 0.00). However, it was not affected by the duration of the disease and the current CD4 counts (p > 0.05). CONCLUSION: Human immunodeficiency viruses (HIV) associated neurocognitive disorders HAND is common in HIV-positive patients, most of whom are asymptomatic. Older patients with less education and severe disease, having lower nadir counts are at the highest risk of HAND. Memory, verbal fluency, and visuospatial abilities were the most commonly affected domains.

Correlates of the HIV-associated neurocognitive disorders among adults living with HIV in Dodoma region, central Tanzania: A cross-sectional study.

BACKGROUND: HIV-associated neurocognitive disorders (HAND) continue to manifest despite advancements and improved antiretroviral therapy coverage. Neurocognitive impairment is a significant predictor of poor prognosis related to poor antiretroviral therapy adherence and retention in HIV care. METHODS: This cross-sectional study examined 397 participants attending cared for and treatment at Dodoma Regional Referral Hospital (DRRH) and selected by systematic sampling. The combination of Montreal Cognitive Assessment (MoCA), International HIV Dementia Scale (IHDS), and The Lawton Instrumental Activity of Daily Living (IADL) were used to assess HIV-associated neurocognitive disorders. Factors associated with HAND were determined using univariate and multivariable logistic regression. RESULTS: Of 397 participants, 234(59.1%) met the criteria for HAND with 231(58.2%) comprising asymptomatic neurocognitive disorder (ANI) or mild neurocognitive disorders (MND), and 3 (0.76%) HIV- associated dementia (HAD). Participants with HAND had significantly poorer performance in each cognitive domain on both MoCA and IHDS. Under multivariable regression, age of 55 years or above with Adjusted Odds Ratio (AOR): 3.5 (95%CI: 1.1, 11.6), p = 0.041 and female gender (AOR): 2.7 (95%CI: 1, 6, 4.5), p<0.001 were significantly associated with HAND. Adherence to antiretroviral therapy AOR: 0.4(95%CI: 0.2, 1.0), p = 0.044, and attaining primary education AOR: 0.3(95%CI: 0.1, 0.8), p = 0.01 or secondary education AOR: 0.1(95%CI: 0.03, 0.2), p<0.001 compared to having no formal education showed good cognitive performance. CONCLUSION: HIV-associated neurocognitive disorders are common in HIV, especially ANI and MND, are common in HIV infected Tanzanians. Both socio-demographic and clinical variables influence neurocognitive functioning in this population. Screening for mild neurocognitive disorders may be indicated if effective treatment becomes available.

Value of Radiomic Analysis Combined With Diffusion Tensor Imaging in Early Diagnosis of HIV-Associated Neurocognitive Disorders.

BACKGROUND: The combination of radiomics and diffusion tensor imaging (DTI) may have potential clinical value in the early stage of HIV-associated neurocognitive disorders (HAND). PURPOSE: To investigate the value of DTI-based radiomics in the early stage of HAND in people living with HIV (PLWH). STUDY TYPE: Retrospective. POPULATION: A total of 138 male PLWH were included, including 68 with intact cognition (IC) and 70 with asymptomatic neurocognitive impairment (ANI). Seventy healthy controls (HCs) were recruited for tract-based spatial statistics (TBSS) analysis. All PLWHs were randomly divided into training and validation cohorts at a 7:3 ratio. FIELD STRENGTH/SEQUENCE: A 3 T, single-shot spin-echo echo planar imaging (EPI). ASSESSMENT: The differences between the PLWH groups were compared using TBSS and region of interest (ROI) analysis. Radiomic features were extracted from the corpus callosum (CC) on DTI postprocessed images, including fractional anisotropy (FA), axial diffusivity (AD), mean diffusivity (MD), and radial diffusivity (RD). The performance of the radiomic signatures was evaluated by ROC curve analysis. The radiomic signature with the highest area under the curve (AUC) was combined with clinical characteristics to construct a nomogram. Decision curve analysis (DCA) was performed to evaluate the ability of different methods in discriminating ANI. STATISTICAL TESTS: Chi-square test, independent-samples t test, Kruskal-Wallis test, Mann-Whitney U test, threshold-free cluster enhancement (TFCE), ROC curve analysis, DCA, multivariate logistic regression analysis, Hosmer-Lemeshow test. P < 0.05 with TFCE corrected and P < 0.0001 without TFCE corrected were considered statistically significant. RESULTS: The ANI group showed lower FA and higher AD than the IC group. In the validation cohort, the AUCs of the FA-, AD-, MD- and RD-based radiomic signatures and the clinicoradiomic nomogram were 0.829, 0.779, 0.790, 0.864, and 0.874, respectively. DCA revealed that the nomogram was of greater clinical value than TBSS analysis, the clinical models, and the RD-based radiomic signature. DATA CONCLUSION: The combination of DTI and radiomics is correlated with early stage of HAND in PLWH. EVIDENCE LEVEL: 3. TECHNICAL EFFICACY: Stage 2.

Acceptability and Feasibility of Genetic Testing to Assess Risk of HIV-Associated Neurocognitive Impairment Among Thai Adolescents and Young Adults.

Host genetic factors may modify the risk of developing HIV-associated neurocognitive impairment (HIV-NCI), and genetic research has the potential to inform novel treatments for HIV-NCI. However, there is a need to better understand the acceptability of genetic testing among distinct populations of people living with HIV at increased risk for HIV-NCI, such as young people living with perinatally acquired HIV (PHIV) in low- and middle-income countries, to gauge the feasibility of genetic research within these populations. This pilot study evaluated the acceptability and feasibility of genetic testing to assess risk of future neurocognitive problems in 50 Thai adolescents and young adults (13-24 years; Meanage = 19.16 [standard deviation = 3.09]; 52% female) with PHIV and demographically similar HIV-negative controls. Participants (25 PHIV; 25 controls) completed a survey assessing acceptability of and concerns about genetic testing and were asked to provide blood samples for genetic testing. Descriptive statistics and blood draw completion rates were produced and calculated. Reported concerns about genetic testing were grouped thematically and tallied. Independent t tests and chi-squares explored demographic differences between participants who reported concerns and peers. Results indicated 46 participants (92%) rated genetic testing as "acceptable" or "completely acceptable." Eight participants (16%) reported concerns about genetic testing. The most common concerns were related to genetic information being shared or misused. Compared with participants without concerns, participants who reported concerns had more years of education and were more likely to have postsecondary schooling. Regarding completion rates, 49 participants (98%) agreed to genetic testing and provided blood samples. Overall, results support the acceptability and feasibility of incorporating genetic testing into research investigating HIV-NCI among adolescents and young adults in Thailand. Findings provide important considerations for planning future genetic studies among young people in Thailand.

Age-Related Perioperative Neurocognitive Disorders: Experimental Models and Druggable Targets.

With the worldwide increase in life span, surgical patients are becoming older and have a greater propensity for postoperative cognitive impairment, either new onset or through deterioration of an existing condition; in both conditions, knowledge of the patient's preoperative cognitive function and postoperative cognitive trajectory is imperative. We describe the clinical utility of a tablet-based technique for rapid assessment of the memory and attentiveness domains required for executive function. The pathogenic mechanisms for perioperative neurocognitive disorders have been investigated in animal models in which excessive and/or prolonged postoperative neuroinflammation has emerged as a likely contender. The cellular and molecular species involved in postoperative neuroinflammation are the putative targets for future therapeutic interventions that are efficacious and do not interfere with the surgical patient's healing process.

Microfluidics-assisted blood-brain barrier device: a powerful tool to study perioperative neurocognitive disorder.

The dysfunction of the blood-brain barrier could contribute to the pathogenesis of the perioperative neurocognitive disorder. In a recent study published in the British Journal of Anaesthesia, Yang and colleagues developed an innovative microfluidics-assisted blood-brain barrier device to investigate the effects of neuroimmune interactions on blood-brain barrier opening. The findings are important and timely to understanding the mechanistic insights of perioperative neurocognitive disorder.

Targeting neuroinflammation as a preventive and therapeutic approach for perioperative neurocognitive disorders.

Perioperative neurocognitive disorders (PND) is a common postoperative complication associated with regional or general anesthesia and surgery. Growing evidence in both patient and animal models of PND suggested that neuroinflammation plays a critical role in the development and progression of this problem, therefore, mounting efforts have been made to develop novel therapeutic approaches for PND by targeting specific factors or steps alongside the neuroinflammation. Multiple studies have shown that perioperative anti-neuroinflammatory strategies via administering pharmacologic agents or performing nonpharmacologic approaches exert benefits in the prevention and management of PND, although more clinical evidence is urgently needed to testify or confirm these results. Furthermore, long-term effects and outcomes with respect to cognitive functions and side effects are needed to be observed. In this review, we discuss recent preclinical and clinical studies published within a decade as potential preventive and therapeutic approaches targeting neuroinflammation for PND.

Elevation of brain ADC (apparent diffusion coefficient) in HIV-associated neurocognitive disorders and evolution after treatment: A pilot study.

BACKGROUND: Thirty to 50% of HIV-infected patients develop HIV-Associated Neurocognitive Disorders (HAND) despite virological control. The previously published Neuro+3 study showed their neurocognitive status can be improved by intensifying antiviral therapy. Our study is a part of the Neuro3+ study and aims to study apparent diffusion coefficient (ADC) as a biomarker for neurological improvement. PATIENTS AND METHODS: We prospectively included 31 patients with HAND. They received therapy with better CNS Penetration Effectiveness (CPE) score with two-year follow-up. Cognitive status was assessed at day 0 (D0) and week 96 (W96) using Frascati 3-stage classification and Global Deficit Score (GDS). Brain MRI at D0 and W96 assessed morphological data (white matter hyperintensities, opportunistic infections, ischemic lesions, atrophy) and measured whole brain apparent diffusion coefficient (ADC). We compared their data with a control group of 20 healthy patients with similar ages and sex ratio. RESULTS: After ARV intensification, cognitive status was significantly improved: GDS (n = 1,4 vs 1,0 p = 0.01) and Frascati scale (2HAD/22MND/7ANI vs 1HAD/8MND/17ANI p = 0.001). Mean ADC was significantly higher in patients at inclusion than in controls (0.88 × 10-3 mm2/s ± 0.06 vs 0.81 × 10-3 mm2/s ± 0.04, p = 0.0001). ADC decreased after treatment (0.88 × 10-3 mm2/s ± 0.06 vs 0.85 × 10-3 mm2/s ± 0.06 (p = 0,04). In subgroup analysis, ADC significantly decreased in clinically improved patients (0.89 × 10-3 mm2/s ± 0.07 vs 0.85 × 10-3 mm2/s ± 0.07 (p = 0,03)) and did not significantly change in non-clinically improved patients (0.86 × 10-3 mm2/s ± 0.07 vs 0.84 × 10-3 mm2/s ± 0.07 (p = 0,31)). After treatment, there was no significant difference between patients and controls (0.85 × 10-3 mm2/s ± 0.06 vs 0.81 × 10-3 mm2/s ± 0.04, p = 0.17). CONCLUSION: Whole-brain ADC is a good biomarker of HIV-associated neurocognitive disorders. It is significantly increased in patients with HAND compared with controls and significantly decreases after treatment. It is all the more important to have a quantitative biomarker as conventional imaging does not contribute to the diagnosis.

Interleukin-6 trans-signalling in hippocampal CA1 neurones mediates perioperative neurocognitive disorders in mice.

BACKGROUND: Interleukin-6 (IL-6), a pleiotropic cytokine with both degenerative and regenerative properties, is necessary and sufficient to provoke perioperative neurocognitive disorders after aseptic trauma in mice. IL-6 initiates its actions after binding to either membrane-bound IL-6 receptor α (mIL-6Rα) through classical signalling, or soluble IL-6 receptor (IL-6R) through trans-signalling; both signalling pathways require the transducer gp130. We investigated the site and type of IL-6 signalling that pertains in a tibial fracture aseptic trauma model of perioperative neurocognitive disorder. METHODS: Wild-type or genetically altered adult mice that lacked molecules unique to either classical or trans-IL-6 signalling underwent tibial fracture under isoflurane anaesthesia. In separate cohorts, we assessed postoperative memory using a trace fear conditioning paradigm (72 h postoperatively), and post-receptor IL-6 signalling (24 h postoperatively) using phosphorylation of signal transducer and activator of transcription 3 (pSTAT3) in CA1 hippocampal neurones. Fracture healing was assessed at postoperative day 15 after inhibiting either both forms of IL-6 signalling with BE0047 or only trans-signalling with sgp130Fc. RESULTS: The surgical phenotype of memory decline (decrease in freezing in trace fear conditioning) and upregulated IL-6 signalling (pSTAT3) did not occur after pretreatment before surgery with either BE0047 or sgp130Fc, or after depleting gp130 from CA1 neurones. The surgical phenotype still occurred when IL-6Rα was depleted in either CA1 hippocampal neurones (freezing time, 38.9% [11.5%] vs 58.4% [12.3%]; pSTAT+ CA1 neurones, 31.7 [4.9] vs 7.0 [3.1]) or microglia (freezing time, 40.1% [13.9%] vs 65.2% [12.6%]; pSTAT+ CA1 neurones, 30.1 [5.5] vs 7.9 [3.2]). In global IL-6Rα-/- mice, hyper-IL-6, the trans-signalling agonist, produced the surgical phenotype when administered i.c.v. (freezing time, 42.4% [8.8%] vs 59.7% [10.4%]; pSTAT+ cells, 29.3 [4.3] vs 10.0 [4.4]). Bone-fracture healing (% of fracture callus comprised of new collagen) was significantly greater with sgp130Fc than with BE0047 (52.2% [8.3%] vs 39.7% [7.9%]). CONCLUSIONS: After orthopaedic trauma, IL-6 produces perioperative neurocognitive disorders through IL-6 trans-signalling in mouse CA1 neurones. Druggable targets of the trans-signalling pathway should be sought to reduce perioperative neurocognitive disorders while allowing the healing properties of classical IL-6 signalling.

Vitamin C deficiency induces hypoglycemia and cognitive disorder through S-nitrosylation-mediated activation of glycogen synthase kinase 3ß.

Vitamin C (VC, l-ascorbic acid) is an essential nutrient that plays a key role in metabolism and functions as a potent antioxidant in regulating the S-nitrosylation and denitrosylation of target proteins. The precise function of VC deprivation in glucose homeostasis is still unknown. In the absence of L-gulono-1,4-lactone oxidoreductase, an essential enzyme for the last step of VC synthesis, VC deprivation resulted in persistent hypoglycemia and subsequent impairment of cognitive functions in female but not male mouse pups. The cognitive disorders caused by VC deprivation were largely reversed when these female pups were given glucose. VC deprivation-induced S-nitrosylation of glycogen synthase kinase 3ß (GSK3ß) at Cys14, which activated GSK3ß and inactivated glycogen synthase to decrease glycogen synthesis and storage under the feeding condition, while VC deprivation inactivated glycogen phosphorylase to decrease glycogenolysis under the fasting condition, ultimately leading to hypoglycemia and cognitive disorders. Treatment with Nω-Nitro-l-arginine methyl ester (l-NAME), a specific inhibitor of nitric oxide synthase, on the other hand, effectively prevented S-nitrosylation and activation of GSK3ß in female pups in response to the VC deprivation and reversed hypoglycemia and cognitive disorders. Overall, this research identifies S-nitrosylation of GSK3ß and subsequent GSK3ß activation as a previously unknown mechanism controlling glucose homeostasis in female pups in response to VC deprivation, implying that VC supplementation in the prevention of hypoglycemia and cognitive disorders should be considered in the certain groups of people, particularly young females.