The latest medical research on Neurodegenerative Disorders

The research magnet gathers the latest research from around the web, based on your specialty area. Below you will find a sample of some of the most recent articles from reputable medical journals about neurodegenerative disorders gathered by our medical AI research bot.

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Automatic Measurement of Postural Abnormalities With a Pose Estimation Algorithm in Parkinson's Disease.

Journal of Movement Disorders

This study aims to develop an automated and objective tool to evaluate postural abnormalities in Parkinson's disease (PD) patients.

We applied a deep learning-based pose-estimation algorithm to lateral photos of prospectively enrolled PD patients (n = 28). We automatically measured the anterior flexion angle (AFA) and dropped head angle (DHA), which were validated with conventional manual labeling methods.

The automatically measured DHA and AFA were in excellent agreement with manual labeling methods (intraclass correlation coefficient > 0.95) with mean bias equal to or less than 3 degrees.

The deep learning-based pose-estimation algorithm objectively measured postural abnormalities in PD patients.

Murine roseolovirus does not accelerate amyloid-β pathology and human roseoloviruses are not over-represented in Alzheimer disease brains.

Molecular Neurodegeneration

The role of viral infection in Alzheimer Disease (AD) pathogenesis is an area of great interest in recent years. Several studies have suggested an association between the human roseoloviruses, HHV-6 and HHV-7, and AD. Amyloid-β (Aβ) plaques are a hallmark neuropathological finding of AD and were recently proposed to have an antimicrobial function in response to infection. Identifying a causative and mechanistic role of human roseoloviruses in AD has been confounded by limitations in performing in vivo studies. Recent -omics based approaches have demonstrated conflicting associations between human roseoloviruses and AD. Murine roseolovirus (MRV) is a natural murine pathogen that is highly-related to the human roseoloviruses, providing an opportunity to perform well-controlled studies of the impact of roseolovirus on Aβ deposition.

We utilized the 5XFAD mouse model to test whether MRV induces Aβ deposition in vivo. We also evaluated viral load and neuropathogenesis of MRV infection. To evaluate Aβ interaction with MRV, we performed electron microscopy. RNA-sequencing of a cohort of AD brains compared to control was used to investigate the association between human roseolovirus and AD.

We found that 5XFAD mice were susceptible to MRV infection and developed neuroinflammation. Moreover, we demonstrated that Aβ interacts with viral particles in vitro and, subsequent to this interaction, can disrupt infection. Despite this, neither peripheral nor brain infection with MRV increased or accelerated Aβ plaque formation. Moreover, -omics based approaches have demonstrated conflicting associations between human roseoloviruses and AD. Our RNA-sequencing analysis of a cohort of AD brains compared to controls did not show an association between roseolovirus infection and AD.

Although MRV does infect the brain and cause transient neuroinflammation, our data do not support a role for murine or human roseoloviruses in the development of Aβ plaque formation and AD.

Dynamic changes of CSF sPDGFRβ during ageing and AD progression and associations with CSF ATN biomarkers.

Molecular Neurodegeneration

Loss of brain capillary pericyte is involved in the pathologies and cognitive deficits in Alzheimer's disease (AD). The role of pericyte in early stage of AD pathogenesis remains unclear.

We investigated the dynamic changes of soluble platelet-derived growth factor receptor β (sPDGFRβ) in cerebrospinal fluid (CSF), a marker of brain pericyte injury, in transition from normal ageing to early AD in a cognitively unimpaired population aged 20 to 90 years. Association between sPDGFRβ and ATN biomarkers were analyzed.

In lifetime, CSF sPDGFRβ continually increased since age of 20 years, followed by the increases of phosphorylated tau-181 (P-tau181) and total tau (T-tau) at the age of 22.2 years and 31.7 years, respectively; CSF Aβ42 began to decline since the age of 39.6 years, indicating Aβ deposition. The natural trajectories of biomarkers suggest that pericyte injury is an early event during transition from normal status to AD, even earlier than Aβ deposition. In AD spectrum, CSF sPDGFRβ was elevated in preclinical stage 2 and participants with suspected non-AD pathophysiologies. Additionally, CSF sPDGFRβ was positively associated with P-tau181 and T-tau independently of Aβ42, and significantly strengthened the effects of Aβ42 on P-tau181, suggesting that pericyte injury accelerates Aβ-mediated tau hyperphosphorylation.

Our results suggest that pericyte injury contributes to AD progression in the early stage in an Aβ-independent pathway. Recovery of pericyte function would be a target for prevention and early intervention of AD.

Characterizing Long-term Disability Progression and Employment in NARCOMS Registry Participants with Multiple Sclerosis Taking Dimethyl Fumarate.

International J MS Care

Delayed-release dimethyl fumarate (DMF) is effective in relapsing-remitting multiple sclerosis (RRMS), but long-term effects of DMF on disability and disease progression in clinical settings are unknown. We evaluated disability and employment outcomes in persons with RRMS treated with DMF for up to 5 years.

This longitudinal study included US North American Research Committee on Multiple Sclerosis (NARCOMS) Registry participants with RRMS reporting DMF initiation in fall 2013 through spring 2018 with 1 year or more of follow-up. Time to 6-month confirmed disability progression (≥1-point increase in Patient-Determined Disease Steps [PDDS] score) and change in employment status were evaluated using Kaplan-Meier analysis. Participants were censored at last follow-up or at DMF discontinuation, whichever came first.

During the study, 725 US participants with RRMS had at least 1 year of DMF follow-up data, of whom most were female and White. At year 5, 69.9% (95% CI, 65.4%-73.9%) of these participants were free from 6-month confirmed disability progression, and 84.7% (95% CI, 78.6%-89.2%) were free from conversion to secondary progressive MS. Of 116 participants with data at baseline and year 5, most had stable or improved PDDS and Performance Scales scores over 5 years. Of 322 participants 62 years and younger and employed at the index survey, 66.0% (95% CI, 57.6%-73.1%) were free from a negative change in employment type over 5 years.

Most US NARCOMS Registry participants treated up to 5 years with DMF remained free from 6-month confirmed disability progression and conversion to secondary progressive MS and had stable disability and employment status. These results support the long-term stability of disability and work-related outcomes with disease-modifying therapy.

A Survey of Cannabis Use in a Large US-Based Cohort of People with Multiple Sclerosis.

International J MS Care

As cannabis products become increasingly accessible across the United States, it is important to understand the contemporary use of cannabis for managing multiple sclerosis (MS) symptoms.

We invited participants with MS from the North American Research Committee on Multiple Sclerosis (NARCOMS) Registry (aged 18 years or older) to complete a supplemental survey on cannabis use between March and April 2020. Participants reported cannabis use, treated symptoms, patterns, preferences, methods of use, and the factors limiting use. Findings are reported using descriptive statistics.

Of the 6934 participants invited, 3249 responded. Of the respondents, 31% reported having ever used cannabis to treat MS symptoms, with 20% currently using cannabis. The remaining 69% had never used cannabis for MS symptoms, for reasons including not enough data about efficacy (40%) and safety (27%), and concerns about legality (25%) and cost (18%). The most common symptoms current users were attempting to treat were spasticity (80%), pain (69%), and sleep problems (61%). Ever users (vs never users) were more likely to be younger, be non-White, have lower education, reside in the Northeast and West, be unemployed, be younger at symptom onset, be currently smoking, and have higher levels of disability and MS-related symptoms (all P < .001).

Despite concerns about insufficient safety and efficacy data, legality, and cost, almost one-third of NARCOMS Registry respondents report having tried nonprescription cannabis products in an attempt to alleviate their symptoms. Given the lack of efficacy and safety data on such products, future research in this area is warranted.

Assessing Access to Five Types of Insurance by People with Multiple Sclerosis Using a Cross-sectional Online Survey.

International J MS Care

Many individuals with multiple sclerosis (MS) depart the workforce prematurely. In the United States, access to insurance, including health, disability income, long-term care, and life insurance, is largely employment-based or purchased from earnings. Many individuals we see in the clinic experience financial hardship because of a lack of insurance, even if working. We sought to determine the proportion of workers who are financially protected through insurance coverage and the sources of this coverage in a large sample.

We developed an online survey and opened it to individuals aged 18 to 65 years registered with the North American Research Committee on Multiple Sclerosis, iConquerMS, or the National Multiple Sclerosis Society Minority Advisory Council. Data collected included demographic and disease characteristics, current information about each insurance type (coverage vs no coverage), and when the current insurance policies were obtained relative to MS diagnosis.

Of 2507 survey respondents, 82.9% were female, 3.8% Hispanic/Latino, and 91.2% White. The mean ± SD age was 53.5 ± 8.5 years and disease duration was 16.4 ± 8.5 years after diagnosis. The most frequently held insurance types were health (96.3%) and life (58.8%). Only 9.7% of respondents had long-term care insurance. Except for life insurance, most current policies were obtained after MS diagnosis.

Individuals with MS might not prioritize the possible short- and long-term benefits of these types of insurance. Health care providers can direct patients to nonprofit agencies that educate about of these insurance types and emphasize that others with MS have obtained these insurance types after their diagnosis.

The North American Registry for Care and Research in Multiple Sclerosis (NARCRMS).

International J MS Care

Although many regional multiple sclerosis (MS) databases existed in the United States and Canada, there was no single clinician-derived registry th...

NARCOMS and Other Registries in Multiple Sclerosis: Issues and Insights.

International J MS Care

Observational studies and registries can play a critical role in elucidating the natural and treated history of multiple sclerosis (MS) and identif...

Fat-rich versus carbohydrate-rich nutrition in ALS: a randomised controlled study.

Neurology, Neurosurgery and Psychiatry

There is growing evidence that the course of amyotrophic lateral sclerosis (ALS) may be influenced beneficially by applying high-caloric food supplements (HCSs). However, it is unknown which composition of nutrients offers optimal tolerability and weight gain.

We conducted a randomised controlled study (Safety and Tolerability of Ultra-high-caloric Food Supplements in Amyotrophic Lateral Sclerosis (ALS); TOLCAL-ALS study) in 64 patients with possible, probable or definite ALS according to El Escorial criteria. Patients were randomised into four groups: a high-caloric fatty supplement (HCFS; 405 kcal/day, 100% fat), an ultra-high-caloric fatty supplement (UHCFS; 810 kcal/day, 100% fat), an ultra-high-caloric, carbohydrate-rich supplement (UHCCS; 900 kcal/day, 49% carbohydrates) and an open control (OC) group without any supplement. The primary endpoint was tolerability. Patients were followed up over 4 weeks.

Gastrointestinal side effects were most frequent in the UHCFS group (75.0%), while loss of appetite was most frequent in the UHCCS group (35.3%). During intervention, patients gained +0.9 kg/month of body weight (IQR -0.9 to 1.5; p=0.03) in the HCFS group and +0.9 kg/month (IQR -0.8 to 2.0; p=0.05) in the UHCFS group. A non-significant trend for weight gain (+0.6 kg/month (IQR -0.3 to 1.9; p=0.08)) was observed in the UHCCS group. Patients in OC group continued to lose body weight (-0.5 kg/month, IQR -1.4 to 1.3; p=0.42).

The findings suggest that HCSs frequently cause mild to moderate tolerability issues in patients with ALS, most notably gastrointestinal symptoms in high-fat supplements, and loss of appetite in high-carbohydrate supplements. All three HCSs tested are suited to increase body weight.

Development of novel clinical examination scales for the measurement of disease severity in Creutzfeldt-Jakob disease.

Neurology, Neurosurgery and Psychiatry

To use a robust statistical methodology to develop and validate clinical rating scales quantifying longitudinal motor and cognitive dysfunction in sporadic Creutzfeldt-Jakob disease (sCJD) at the bedside.

Rasch analysis was used to iteratively construct interval scales measuring composite cognitive and motor dysfunction from pooled bedside neurocognitive examinations collected as part of the prospective National Prion Monitoring Cohort study, October 2008-December 2016.A longitudinal clinical examination dataset constructed from 528 patients with sCJD, comprising 1030 Motor Scale and 757 Cognitive Scale scores over 130 patient-years of study, was used to demonstrate scale utility.

The Rasch-derived Motor Scale consists of 8 items, including assessments reliant on pyramidal, extrapyramidal and cerebellar systems. The Cognitive Scale comprises 6 items, and includes measures of executive function, language, visual perception and memory. Both scales are unidimensional, perform independently of age or gender and have excellent inter-rater reliability. They can be completed in minutes at the bedside, as part of a normal neurocognitive examination. A composite Examination Scale can be derived by averaging both scores. Several scale uses, in measuring longitudinal change, prognosis and phenotypic heterogeneity are illustrated.

These two novel sCJD Motor and Cognitive Scales and the composite Examination Scale should prove useful to objectively measure phenotypic and clinical change in future clinical trials and for patient stratification. This statistical approach can help to overcome obstacles to assessing clinical change in rapidly progressive, multisystem conditions with limited longitudinal follow-up.

Edaravone activates the GDNF/RET neurotrophic signaling pathway and protects mRNA-induced motor neurons from iPS cells.

Molecular Neurodegeneration

Spinal cord motor neurons (MNs) from human iPS cells (iPSCs) have wide applications in disease modeling and therapeutic development for amyotrophic lateral sclerosis (ALS) and other MN-associated neurodegenerative diseases. We need highly efficient MN differentiation strategies for generating iPSC-derived disease models that closely recapitulate the genetic and phenotypic complexity of ALS. An important application of these models is to understand molecular mechanisms of action of FDA-approved ALS drugs that only show modest clinical efficacy. Novel mechanistic insights will help us design optimal therapeutic strategies together with predictive biomarkers to achieve better efficacy.

We induce efficient MN differentiation from iPSCs in 4 days using synthetic mRNAs coding two transcription factors (Ngn2 and Olig2) with phosphosite modification. These MNs after extensive characterization were applied in electrophysiological and neurotoxicity assays as well as transcriptomic analysis, to study the neuroprotective effect and molecular mechanisms of edaravone, an FDA-approved drug for ALS, for improving its clinical efficacy.

We generate highly pure and functional mRNA-induced MNs (miMNs) from control and ALS iPSCs, as well as embryonic stem cells. Edaravone alleviates H2O2-induced neurotoxicity and electrophysiological dysfunction in miMNs, demonstrating its neuroprotective effect that was also found in the glutamate-induced miMN neurotoxicity model. Guided by the transcriptomic analysis, we show a previously unrecognized effect of edaravone to induce the GDNF receptor RET and the GDNF/RET neurotrophic signaling in vitro and in vivo, suggesting a clinically translatable strategy to activate this key neuroprotective signaling. Notably, edaravone can replace required neurotrophic factors (BDNF and GDNF) to support long-term miMN survival and maturation, further supporting the neurotrophic function of edaravone-activated signaling. Furthermore, we show that edaravone and GDNF combined treatment more effectively protects miMNs from H2O2-induced neurotoxicity than single treatment, suggesting a potential combination strategy for ALS treatment.

This study provides methodology to facilitate iPSC differentiation and disease modeling. Our discoveries will facilitate the development of optimal edaravone-based therapies for ALS and potentially other neurodegenerative diseases.

A novel H129-based anterograde monosynaptic tracer exhibits features of strong labeling intensity, high tracing efficiency, and reduced retrograde labeling.

Molecular Neurodegeneration

Viral tracers are important tools for mapping brain connectomes. The feature of predominant anterograde transneuronal transmission offers herpes simplex virus-1 (HSV-1) strain H129 (HSV1-H129) as a promising candidate to be developed as anterograde viral tracers. In our earlier studies, we developed H129-derived anterograde polysynaptic tracers and TK deficient (H129-dTK) monosynaptic tracers. However, their broad application is limited by some intrinsic drawbacks of the H129-dTK tracers, such as low labeling intensity due to TK deficiency and potential retrograde labeling caused by axon terminal invasion. The glycoprotein K (gK) of HSV-1 plays important roles in virus entry, egress, and virus-induced cell fusion. Its deficiency severely disables virus egress and spread, while only slightly limits viral genome replication and expression of viral proteins. Therefore, we created a novel H129-derived anterograde monosynaptic tracer (H129-dgK) by targeting gK, which overcomes the limitations of H129-dTK.

Using our established platform and pipeline for developing viral tracers, we generated a novel tracer by deleting the gK gene from the H129-G4. The gK-deleted virus (H129-dgK-G4) was reconstituted and propagated in the Vero cell expressing wildtype H129 gK (gKwt) or the mutant gK (gKmut, A40V, C82S, M223I, L224V, V309M), respectively. Then the obtained viral tracers of gKmut pseudotyped and gKwt coated H129-dgK-G4 were tested in vitro and in vivo to characterize their tracing properties.

H129-dgK-G4 expresses high levels of fluorescent proteins, eliminating the requirement of immunostaining for imaging detection. Compared to the TK deficient monosynaptic tracer H129-dTK-G4, H129-dgK-G4 labeled neurons with 1.76-fold stronger fluorescence intensity, and visualized 2.00-fold more postsynaptic neurons in the downstream brain regions. gKmut pseudotyping leads to a 77% decrease in retrograde labeling by reducing axon terminal invasion, and thus dramatically improves the anterograde-specific tracing of H129-dgK-G4. In addition, assisted by the AAV helper trans-complementarily expressing gKwt, H129-dgK-G4 allows for mapping monosynaptic connections and quantifying the circuit connectivity difference in the Alzheimer's disease and control mouse brains.

gKmut pseudotyped H129-dgK-G4, a novel anterograde monosynaptic tracer, overcomes the limitations of H129-dTK tracers, and demonstrates desirable features of strong labeling intensity, high tracing efficiency, and improved anterograde specificity.