Neurofilaments in neurologic disease.

Neurofilaments (NFs), major cytoskeletal constituents of neurons, have emerged as universal biomarkers of neuronal injury. Neuroaxonal damage underlies permanent disability in various neurological conditions. It is crucial to accurately quantify and longitudinally monitor this damage to evaluate disease progression, evaluate treatment effectiveness, contribute to novel treatment development, and offer prognostic insights. Neurofilaments show promise for this purpose, as their levels increase with neuroaxonal damage in both cerebrospinal fluid and blood, independent of specific causal pathways. New assays with high sensitivity allow reliable measurement of neurofilaments in body fluids and open avenues to investigate their role in neurological disorders. This book chapter will delve into the evolving landscape of neurofilaments, starting with their structure and cellular functions within neurons. It will then provide a comprehensive overview of their broad clinical value as biomarkers in diseases affecting the central or peripheral nervous system.

Pathogenic TDP-43 accelerates the generation of toxic exon1 HTT in Huntington's disease knock-in mice.

Huntington's disease (HD) is caused by a CAG repeat expansion in exon1 of the HTT gene that encodes a polyglutamine tract in huntingtin protein. The formation of HTT exon1 fragments with an expanded polyglutamine repeat has been implicated as a key step in the pathogenesis of HD. It was reported that the CAG repeat length-dependent aberrant splicing of exon1 HTT results in a short polyadenylated mRNA that is translated into an exon1 HTT protein. Under normal conditions, TDP-43 is predominantly found in the nucleus, where it regulates gene expression. However, in various pathological conditions, TDP-43 is mislocalized in the cytoplasm. By investigating HD knock-in mice, we explore whether the pathogenic TDP-43 in the cytoplasm contributes to HD pathogenesis, through expressing the cytoplasmic TDP-43 without nuclear localization signal. We found that the cytoplasmic TDP-43 is increased in the HD mouse brain and that its mislocalization could deteriorate the motor and gait behavior. Importantly, the cytoplasmic TDP-43, via its binding to the intron1 sequence (GU/UG)n of the mouse Htt pre-mRNA, promotes the transport of exon1-intron1 Htt onto ribosome, resulting in the aberrant generation of exon1 Htt. Our findings suggest that cytoplasmic TDP-43 contributes to HD pathogenesis via its binding to and transport of nuclear un-spliced mRNA to the ribosome for the generation of a toxic protein product.

Factors Influencing Discharges to Hospice for Patients With Late-Stage Huntington's Disease.

Background: Hospice services for patients with Huntington's disease (HD) are likely beneficial in relieving significant burdens and minimizing costly hospitalizations at the end of life, though there has been little study or clinical guidance on hospice enrollment for patients with HD. Objectives: The primary objective of this study was to identify clinical, sociodemographic, and system-level factors associated with discharges to hospice compared to other dispositions for hospitalized patients with late-stage HD. Methods: These analyses used data from the Nationwide Inpatient Sample between the years 2007 and 2011. Weighted logistic regression with a forward selection approach was performed to identify factors associated with discharge to hospice compared to discharge to home, facility, other locations, and death in hospital. Results: These analyses included 6544 hospitalizations of patients with late-stage HD. There was a significant increasing trend in discharges to hospice over the study period (P < 0.001). After adjustment, multiple clinical, sociodemographic, and system-level variables were identified as being associated with discharges to hospice. Patients with aspiration pneumonia and non-aspiration pneumonias had lower odds of being discharged to hospice compared to dying in the hospital. When comparing to discharges to facilities and home, weight loss and palliative care consultation were associated with greater odds of discharge to hospice. Conclusions: Our findings serve as a foundation for future studies on these factors, and thus help clinician decision-making on when to start advance care planning or end-of-life care for patients with HD. These results also support studies developing hospice referral criteria specific to patients with HD.

Identification of molecular targets and small drug candidates for Huntington's disease via bioinformatics and a network-based screening approach.

Huntington's disease (HD) is a gradually severe neurodegenerative ailment characterised by an increase of a specific trinucleotide repeat sequence (cytosine-adenine-guanine, CAG). It is passed down as a dominant characteristic that worsens over time, creating a significant risk. Despite being monogenetic, the underlying mechanisms as well as biomarkers remain poorly understood. Furthermore, early detection of HD is challenging, and the available diagnostic procedures have low precision and accuracy. The research was conducted to provide knowledge of the biomarkers, pathways and therapeutic targets involved in the molecular processes of HD using informatic based analysis and applying network-based systems biology approaches. The gene expression profile datasets GSE97100 and GSE74201 relevant to HD were studied. As a consequence, 46 differentially expressed genes (DEGs) were identified. 10 hub genes (TPM1, EIF2S3, CCN2, ACTN1, ACTG2, CCN1, CSRP1, EIF1AX, BEX2 and TCEAL5) were further differentiated in the protein-protein interaction (PPI) network. These hub genes were typically down-regulated. Additionally, DEGs-transcription factors (TFs) connections (e.g. GATA2, YY1 and FOXC1), DEG-microRNA (miRNA) interactions (e.g. hsa-miR-124-3p and has-miR-26b-5p) were also comprehensively forecast. Additionally, related gene ontology concepts (e.g. sequence-specific DNA binding and TF activity) connected to DEGs in HD were identified using gene set enrichment analysis (GSEA). Finally, in silico drug design was employed to find candidate drugs for the treatment HD, and while the possible modest therapeutic compounds (e.g. cortistatin A, 13,16-Epoxy-25-hydroxy-17-cheilanthen-19,25-olide, Hecogenin) against HD were expected. Consequently, the results from this study may give researchers useful resources for the experimental validation of Huntington's diagnosis and therapeutic approaches.

Exon 1-targeting miRNA reduces the pathogenic exon 1 HTT protein in Huntington disease models.

Huntington disease (HD) is a fatal neurodegenerative disease caused by a trinucleotide repeat expansion in exon 1 of the huntingtin gene (HTT) resulting in toxic gain-of-function and cell death. Despite its monogenic cause, the pathogenesis of HD is highly complex and increasing evidence indicates that, in addition to the full-length (FL) mutant HTT protein, the expanded exon 1 HTT (HTTexon1) protein that is translated from the HTT1a transcript generated by aberrant splicing is prone to aggregate and may contribute to HD pathology. This finding suggests that reducing the expression of HTT1a may achieve a greater therapeutic benefit than targeting only FL mutant HTT. Conversely, strategies that exclusively target FL HTT may not fully prevent the pathogenesis of HD. We have developed an engineered microRNA targeting the HTT exon 1 sequence (miHTT), delivered via adeno-associated virus serotype 5 (AAV5). The target sequence of miHTT is present in both FL HTT and HTT1a transcripts. Preclinical studies with AAV5-miHTT have demonstrated efficacy in several rodent and large animal models by reducing FL HTT mRNA and protein and rescuing HD-like phenotypes, and have been the rationale for phase I/II clinical studies now ongoing in the US and Europe. In the present study, we evaluated the ability of AAV5-miHTT to reduce the levels of aberrantly spliced HTT1a mRNA and the HTTexon1 protein in the brain of two mouse models of HD (heterozygous zQ175 knock-in mice and humanized Hu128/21 mice). Polyadenylated HTT1a mRNA and HTTexon1 protein were detected in the striatum and cortex of heterozygous zQ175 knock-in mice, but not in wild-type, littermate control mice. Intrastriatal administration of AAV5-miHTT resulted in dose-dependent expression of mature miHTT microRNA in cortical brain regions, accompanied by significant lowering of both FL HTT and HTT1a mRNA expression at two months post-injection. Mutant HTT and HTTexon1 protein levels were also significantly reduced in the striatum and cortex of heterozygous zQ175 knock-in at 2 months after AAV5-miHTT treatment and in humanized Hu128/21 mice 7 months post-treatment. The effects were confirmed in primary Hu128/21 neuronal cultures. These results demonstrate that AAV5-miHTT gene therapy is an effective approach to lower both FL HTT and the pathogenic HTTexon1 levels, which could potentially have an additive therapeutic benefit compared to other HTT-targeting modalities.

Comparing balance using the BESTest in Alzheimer, Huntington and Parkinson disease.

Aim: Individuals with Alzheimer disease (AD), Huntington disease (HD) and Parkinson disease (PD) have impaired balance, and comparing these deficits could improve management of neurological diseases.Methods: Scores on the Balance Evaluation Systems Test (BESTest) were compared across three groups, consisting of individuals with AD, HD and PD in early stages of their respective disease.Results: Individuals with PD had significantly higher scores on the BESTest than individuals with AD (95% CI [4.30, 21.37], p < 0.01) or HD (95% CI [6.53, 24.18], p < 0.001). Individuals with AD and HD were not significantly different on the overall BESTest or any of its subsections.Conclusion: AD and HD may have overlapping pathologies resulting in early and similar balance impairments in these groups.

Balance impairment differs among individuals with Alzheimer disease, Huntington disease and Parkinson disease, with individuals with Parkinson disease demonstrating significantly better balance when compared in early stages of each disease.

Prognostic enrichment for early-stage Huntington's disease: An explainable machine learning approach for clinical trial.

BACKGROUND: In Huntington's disease clinical trials, recruitment and stratification approaches primarily rely on genetic load, cognitive and motor assessment scores. They focus less on in vivo brain imaging markers, which reflect neuropathology well before clinical diagnosis. Machine learning methods offer a degree of sophistication which could significantly improve prognosis and stratification by leveraging multimodal biomarkers from large datasets. Such models specifically tailored to HD gene expansion carriers could further enhance the efficacy of the stratification process. OBJECTIVES: To improve stratification of Huntington's disease individuals for clinical trials. METHODS: We used data from 451 gene positive individuals with Huntington's disease (both premanifest and diagnosed) from previously published cohorts (PREDICT, TRACK, TrackON, and IMAGE). We applied whole-brain parcellation to longitudinal brain scans and measured the rate of lateral ventricular enlargement, over 3 years, which was used as the target variable for our prognostic random forest regression models. The models were trained on various combinations of features at baseline, including genetic load, cognitive and motor assessment score biomarkers, as well as brain imaging-derived features. Furthermore, a simplified stratification model was developed to classify individuals into two homogenous groups (low risk and high risk) based on their anticipated rate of ventricular enlargement. RESULTS: The predictive accuracy of the prognostic models substantially improved by integrating brain imaging features alongside genetic load, cognitive and motor biomarkers: a 24 % reduction in the cross-validated mean absolute error, yielding an error of 530 mm3/year. The stratification model had a cross-validated accuracy of 81 % in differentiating between moderate and fast progressors (precision = 83 %, recall = 80 %). CONCLUSIONS: This study validated the effectiveness of machine learning in differentiating between low- and high-risk individuals based on the rate of ventricular enlargement. The models were exclusively trained using features from HD individuals, which offers a more disease-specific, simplified, and accurate approach for prognostic enrichment compared to relying on features extracted from healthy control groups, as done in previous studies. The proposed method has the potential to enhance clinical utility by: i) enabling more targeted recruitment of individuals for clinical trials, ii) improving post-hoc evaluation of individuals, and iii) ultimately leading to better outcomes for individuals through personalized treatment selection.

Dysregulation of choline metabolism and therapeutic potential of citicoline in Huntington's disease.

Huntington's disease (HD) is associated with dysregulated choline metabolism, but the underlying mechanisms remain unclear. This study investigated the expression of key enzymes in this pathway in R6/2 HD mice and human HD postmortem brain tissues. We further explored the therapeutic potential of modulating choline metabolism for HD. Both R6/2 mice and HD patients exhibited reduced expression of glycerophosphocholine phosphodiesterase 1 (GPCPD1), a key enzyme in choline metabolism, in the striatum and cortex. The striatum of R6/2 mice also showed decreased choline and phosphorylcholine, and increased glycerophosphocholine, suggesting disruption in choline metabolism due to GPCPD1 deficiency. Treatment with citicoline significantly improved motor performance, upregulated anti-apoptotic Bcl2 expression, and reduced oxidative stress marker malondialdehyde in both brain regions. Metabolomic analysis revealed partial restoration of disrupted metabolic patterns in the striatum and cortex following citicoline treatment. These findings strongly suggest the role of GPCPD1 deficiency in choline metabolism dysregulation in HD. The therapeutic potential of citicoline in R6/2 mice highlights the choline metabolic pathway as a promising target for future HD therapies.

The Frequency and Clinical Impact of Synonymous HTT Loss-of-Interruption and Duplication-of-interruption Variants in a Diverse HD Cohort.

PURPOSE: To determine the frequency and clinical impact of loss-of-interruption (LOI) and duplication-of-interruption (DOI) modifier variants of the HTT CAG and CCG repeat in a cohort of individuals with Huntington disease (HD). METHODS: We screened symptomatic HD participants from the UBC HD Biobank and five research sites for sequence variants. Following variant identification, we examined the clinical impact and frequency in the reduced penetrance range. RESULTS: Participants with CAG-CCG LOI and CCG LOI variants have a similar magnitude of earlier onset of HD, by 12.5 years. The sequence variants exhibit ancestry-specific differences. Participants with the CAG-CCG LOI variant also have a faster progression of TMS by 1.9 units per year. Symptomatic participants with the CAG-CCG LOI variant show enrichment in the reduced penetrance range. The CAG-CCG LOI variant explains the onset of two symptomatic HD participants with diagnostic repeats below the pathogenetic range. CONCLUSION: Our findings have significant clinical implications for participants with the CAG-CCG LOI variant who receive inaccurate diagnoses near diagnostic cut-off ranges. Improved diagnostic testing approaches and clinical management are needed for these individuals. We present the largest and most diverse HTT CAG and CCG sequence variant cohort and emphasize their importance in clinical presentation in HD.

Coping with Huntington's Disease in Patients and At-Risk Individuals.

Background: Huntington's disease (HD) presents patients and individuals at risk for HD with significant levels of stress. However, relatively little research has examined how individuals cope with stress related to the disease or the association of specific coping strategies with psychological symptoms. Objective: This study examined the ways in which HD patients and at-risk individuals cope with HD-related stress using a control-based model of coping and the association of coping strategies with symptoms of depression and anxiety. Methods: HD patients (n = 49) and at-risk individuals (n = 76) completed the Responses to Stress Questionnaire - Huntington's Disease Version to assess coping strategies in response to HD-related stress, as well as standardized measures of depression and anxiety symptoms. Patient health records were accessed to obtain information related to disease characteristics. Results: Patients and at-risk individuals reported using comparable levels of primary control coping, secondary control coping, and disengagement coping strategies. In linear regression analyses, only secondary control coping was significantly associated with lower depression (ß= -0.62, p < 0.001) and anxiety (ß= -0.59, p < 0.001) symptoms in patients and at-risk individuals (ß= -0.55, p < 0.001 and ß= -0.50, p < 0.001, respectively). Conclusions: Secondary control coping may be beneficial for both HD patients and at-risk individuals. Future research using the control-based model of coping in longitudinal studies with the HD population is needed, and future interventions could test the effects of cognitive reframing and acceptance as coping strategies for families affected by HD.

Economic Burden of Huntington's Disease: Analysis from a Brazilian Tertiary Care Perspective.

Background: Huntington's disease (HD) exerts significant impacts on individuals and families worldwide. Nevertheless, data on its economic burden in Brazil are scarce, revealing a critical gap in understanding the associated healthcare costs. Objective: This study was conducted at a tertiary neurology outpatient clinic in Brazil with the aim of assessing annual healthcare service utilization and associated costs for HD patients. Methods: We conducted a cross-sectional observational study involving 34 HD patients. A structured questionnaire was applied to collect data on direct medical costs (outpatient services, medications), non-medical direct costs (complementary therapies, mobility aids, home adaptations), and indirect costs (lost productivity, caregiver costs, government benefits) over one year. Results: Significant economic impacts were observed, with average annual direct medical costs of $4686.82 per HD patient. Non-medical direct and indirect costs increased the financial burden, highlighting extensive resource utilization beyond healthcare services. Thirty-three out of 34 HD patients were unemployed or retired, and 16 relied on government benefits, reflecting broader socioeconomic implications. Despite the dataset's limitations, it provides crucial insights into the economic impact of HD on patients and the Brazilian public health system. Conclusions: The findings underscore the urgent need for a more comprehensive evaluation of the costs to inform governmental policies related to HD. Future research is needed to expand the data pool and develop a nuanced understanding of the economic burdens of HD to help formulate effective healthcare strategies for patients.

The meaning of apathy in Huntington's disease: A qualitative study of caregiver perspectives.

Although one of the most prevalent and impactful features of Huntington's disease (HD), little is known about the impact of apathy on HD caregivers, although there is evidence it affects perceptions of distress and burden. Given the importance of the caregivers, we aimed to explore the lived experience of people supporting someone with HD and associated apathy. Semi-structured interviews were conducted with 11 caregivers and analysed using reflective thematic analysis, informed by a phenomenological framework. Five overarching themes were produced: (1) What even is apathy? (2) It makes my life harder: the practical impact of apathy, (3) They haven't forgotten me, but they have forgotten that they ever loved me, (4) I'm grieving for someone who hasn't died yet, and (5) I need a safe space to say what I really feel without fear of judgement. Inter-woven between these themes were complex narratives about the unspoken nature of HD, the invisibility of caregivers who felt trapped and unheard, and the one-sided nature of loving someone with the disease. Findings are discussed in relation to theoretical frameworks of anticipatory grief and ambiguous loss, and situated within the wider literature on caregiving for people with a neurodegenerative condition.

Virtual reality tolerability, sense of presence and usability in Huntington disease: a pilot study.

INTRODUCTION: Several studies demonstrated the utility of immersive virtual reality (VR) as a complementary approach to conventional therapy for improving motor, psychological and cognitive impairment in some pathological conditions. Our pilot study aims to evaluate for the first time: 1) sense of presence, tolerability and usability of VR immersive experience in patients with early stages of Huntington disease (eHDp) compared to healthy controls (HC); 2) correlation between the use of technology/cybersickness and the variables of presence/usability; 3) correlation between clinical characteristics (genetic, motor, functional and cognitive) and VR's variables. METHOD: We recruited 10 eHDp and 10 age, gender and education matched HC. Participants completed questionnaires about sense of presence, usability, tolerability and technology use profile. Subjects were exposed to different VR scenarios from a first-person perspective through a standalone VR headset. RESULTS: Our results showed no significant statistical difference between eHDp and HC for the sense of presence (p=0.910), usability (p=0.744) and tolerability (p=0.730) during the VR experience. Familiarity with the use of technology was also comparable between groups (p=0.676). Regarding correlations in eHDp group, our results showed no correlations between use of technology/tolerability and the sense of presence/usability. Moreover, clinical characteristics of eHDp (genetic, motor, functional and cognitive scores) did not influence the sense of presence, tolerability and usability. CONCLUSION: Our research presents preliminary evidence for the applicability of VR in eHDp. These results open up the possibility to explore future applications of this methodology in rehabilitation (i.e., cognitive training, physiotherapy), diagnosis and psychological support in Huntington disease patients.

Interaction between resveratrol and SIRT1: role in neurodegenerative diseases.

Neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and Huntington's disease, pose significant health challenges and economic burdens worldwide. Recent studies have emphasized the potential therapeutic value of activating silent information regulator-1 (SIRT1) in treating these conditions. Resveratrol, a compound known for its ability to potently activate SIRT1, has demonstrated promising neuroprotective effects by targeting the underlying mechanisms of neurodegeneration. In this review, we delve into the crucial role of resveratrol-mediated SIRT1 upregulation in improving neurodegenerative diseases. The role of the activation of SIRT1 by resveratrol was reviewed. Moreover, network pharmacology was used to elucidate the possible mechanisms of resveratrol in these diseases. Activation of SIRT1 by resveratrol had positive effects on neuronal function and survival and alleviated the hallmark features of these diseases, such as protein aggregation, oxidative stress, neuroinflammation, and mitochondrial dysfunction. In terms of network pharmacology, the signaling pathways by which resveratrol protects against different neurodegenerative diseases were slightly different. Although the precise mechanisms underlying the neuroprotective effects of resveratrol and SIRT1 activation remain under investigation, these findings offer valuable insights into potential therapeutic strategies for neurodegenerative diseases.

Silymarin ameliorates motor function and averts neuroinflammation-induced cell death in the rat model of Huntington's disease.

Huntington's disease (HD) is a scarce neurodegenerative disorder defined by chorea (unusual involuntary movements), behavioral presentations, psychiatric features, and cognitive deterioration. Although the precise pathogenic mechanism behind HD has not yet been identified, the most widely acknowledged pathways include excitotoxicity, mitochondrial malfunction, neuroinflammation, neurochemical imbalance, oxidative stress, and apoptosis HD has no efficient therapy. Current medications have drawbacks. Silymarin, a compound made up of standardized extracts obtained from the seeds of the Silybum marianum and polyphenolic flavonolignan, is utilized in therapeutic settings to treat a variety of experimental disorders in animals. Silymarin's key pharmacological activities include anti-cancer, hepatoprotection, antioxidant, cardioprotection, and anti-inflammatory. It also has no adverse side effects on people or animals. The current study aims to provide Silymarin's neuro-pharmacological activities or therapeutic qualities in HD. In this study, Thirty-six male Sprague-Dawley rats (200-220g, 8 weeks) at the initial of the study were used. Silymarin solution (100mg/Kg) was administered by oral gavage for 21 days to ameliorate neural damage in rats injected with 3-nitropropionicacid (3-NP) in a preliminary rat model of HD. The results showed that administration of silymarin to HD rats reduced gliosis, improved motor coordination and muscle activity, and increased striatal volume and the number of neurons and glial cells. Our results suggest that silymarin provides a protective environment for nerve cells and can have beneficial effects against the harmful effects of HD.

Person-centred integrated care for people living with Parkinson's, Huntington's and Multiple Sclerosis: A systematic review.

INTRODUCTION: People living with long-term neurological conditions (LTNCs) have complex needs that demand intensive care coordination between sectors. This review aimed to establish if integrated care improves outcomes for people, and what characterises successful interventions. METHODS: A systematic review of the literature was undertaken evaluating multisectoral integrated care interventions in people living with Parkinson's disease (PD), Multiple Sclerosis (MS) and Huntington's disease (HD). Strength of evidence was rated for the different outcomes. RESULTS: A total of 15 articles were included, reporting on 2095 patients and caregivers, finding that integrated care can improve people's access to resources and reduce patients' depression. UK studies indicated improvements in patients' quality of life, although the international literature was inconclusive. Few programmes considered caregivers' outcomes, reporting no difference or even worsening in depression, burden and quality of life. Overall, the evidence showed a mismatch between people's needs and outcomes measured, with significant outcomes (e.g., self-management, continuity of care, care experience) lacking. Successful programmes were characterised by expert knowledge, multisectoral care coordination, care continuity and a person-centred approach. CONCLUSIONS: The impact of integrated care programmes on people living with LTNCs is limited and inconclusive. For a more person-centred approach, future studies need to assess integrated care from a service-user perspective. PATIENT AND PUBLIC CONTRIBUTION: Thirty people living with LTNCs were involved in this review, through defining research questions, validating the importance of the project, and increasing the researchers' understanding on what matters to service users. A patient and public involvement subgroup of representatives with lived experience on PD, MS and HD identified the need for more person-centred integrated care, with specific concerns over care fragmentation, care duplication and care continuity. This was key to data analysis and formulating the characteristics of successful and unsuccessful integrated care programmes from the perspective of service users. The discrepancy between service users' needs and the outcomes assessed in the literature point to user-driven research as the solution to address what matters to patients and caregivers.

An automatic measure for speech intelligibility in dysarthrias-validation across multiple languages and neurological disorders.

Introduction: Dysarthria, a motor speech disorder caused by muscle weakness or paralysis, severely impacts speech intelligibility and quality of life. The condition is prevalent in motor speech disorders such as Parkinson's disease (PD), atypical parkinsonism such as progressive supranuclear palsy (PSP), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS). Improving intelligibility is not only an outcome that matters to patients but can also play a critical role as an endpoint in clinical research and drug development. This study validates a digital measure for speech intelligibility, the ki: SB-M intelligibility score, across various motor speech disorders and languages following the Digital Medicine Society (DiMe) V3 framework. Methods: The study used four datasets: healthy controls (HCs) and patients with PD, HD, PSP, and ALS from Czech, Colombian, and German populations. Participants' speech intelligibility was assessed using the ki: SB-M intelligibility score, which is derived from automatic speech recognition (ASR) systems. Verification with inter-ASR reliability and temporal consistency, analytical validation with correlations to gold standard clinical dysarthria scores in each disease, and clinical validation with group comparisons between HCs and patients were performed. Results: Verification showed good to excellent inter-rater reliability between ASR systems and fair to good consistency. Analytical validation revealed significant correlations between the SB-M intelligibility score and established clinical measures for speech impairments across all patient groups and languages. Clinical validation demonstrated significant differences in intelligibility scores between pathological groups and healthy controls, indicating the measure's discriminative capability. Discussion: The ki: SB-M intelligibility score is a reliable, valid, and clinically relevant tool for assessing speech intelligibility in motor speech disorders. It holds promise for improving clinical trials through automated, objective, and scalable assessments. Future studies should explore its utility in monitoring disease progression and therapeutic efficacy as well as add data from further dysarthrias to the validation.

Stress-Related Roles of Exosomes and Exosomal miRNAs in Common Neuropsychiatric Disorders.

Exosomes, natural nanovesicles that contain a cargo of biologically active molecules such as lipids, proteins, and nucleic acids, are released from cells to the extracellular environment. They then act as autocrine, paracrine, or endocrine mediators of communication between cells by delivering their cargo into recipient cells and causing downstream effects. Exosomes are greatly enriched in miRNAs, which are small non-coding RNAs that act both as cytoplasmic post-transcriptional repression agents, modulating the translation of mRNAs into proteins, as well as nuclear transcriptional gene activators. Neuronal exosomal miRNAs have important physiologic functions in the central nervous system (CNS), including cell-to-cell communication, synaptic plasticity, and neurogenesis, as well as modulating stress and inflammatory responses. Stress-induced changes in exosomal functions include effects on neurogenesis and neuroinflammation, which can lead to the appearance of various neuropsychiatric disorders such as schizophrenia, major depression, bipolar disorder, and Alzheimer's and Huntington's diseases. The current knowledge regarding the roles of exosomes in the pathophysiology of common mental disorders is discussed in this review.

TDP43 and Huntingtin Exon-1 Undergo A Conformationally Specific Interaction That Strongly Alters the Fibril Formation of Both Proteins.

Protein aggregation is a common feature of many neurodegenerative diseases. In Huntington's disease, mutant huntingtin is the primary aggregating protein, but the aggregation of other proteins, such as TDP43, is likely to further contribute to toxicity. Moreover, mutant huntingtin is also a risk factor for TDP pathology in ALS. Despite this co-pathology of huntingtin and TDP43, it remains unknown whether these amyloidogenic proteins directly interact with each other. Using a combination of biophysical methods, we show that the aggregation prone regions of both proteins, huntingtin exon-1 (Httex1) and the TDP43 low complexity domain (TDP43-LCD), interact in a conformationally specific manner. This interaction significantly slows Httex1 aggregation, while it accelerates TDP43-LCD aggregation. A key intermediate responsible for both effects is a complex formed by liquid TDP43-LCD condensates and Httex1 fibrils. This complex shields seeding competent surfaces of Httex1 fibrils from Httex1 monomers, which are excluded from the condensates. In contrast, TDP43-LCD condensates undergo an accelerated liquid-to-solid transition upon exposure to Httex1 fibrils. Cellular studies show co-aggregation of untagged Httex1 with TDP43. This interaction causes mislocalization of TDP43, which has been linked to TDP43 toxicity. The protection from Httex1 aggregation in lieu of TDP43-LCD aggregation is interesting, as it mirrors what has been found in disease models, namely that TDP43 can protect from huntingtin toxicity, while mutant huntingtin can promote TDP43 pathology. These results suggest that direct protein interaction could, at least in part, be responsible for the linked pathologies of both proteins.