The latest medical research on Motor Neuron Disease

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 motor neuron disease gathered by our medical AI research bot.

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Dysregulation of innate immune signaling in animal models of spinal muscular atrophy.

Motor Neuron Disease

Spinal muscular atrophy (SMA) is a devastating neuromuscular disease caused by hypomorphic loss of function in the survival motor neuron (SMN) protein. SMA presents across a broad spectrum of disease severity. Unfortunately, genetic models of intermediate SMA have been difficult to generate in vertebrates and are thus unable to address key aspects of disease etiology. To address these issues, we developed a Drosophila model system that recapitulates the full range of SMA severity, allowing studies of pre-onset biology as well as late-stage disease processes.

Here, we carried out transcriptomic and proteomic profiling of mild and intermediate Drosophila models of SMA to elucidate molecules and pathways that contribute to the disease. Using this approach, we elaborated a role for the SMN complex in the regulation of innate immune signaling. We find that mutation or tissue-specific depletion of SMN induces hyperactivation of the immune deficiency (IMD) and Toll pathways, leading to overexpression of antimicrobial peptides (AMPs) and ectopic formation of melanotic masses in the absence of an external challenge. Furthermore, the knockdown of downstream targets of these signaling pathways reduced melanotic mass formation caused by SMN loss. Importantly, we identify SMN as a negative regulator of a ubiquitylation complex that includes Traf6, Bendless, and Diap2 and plays a pivotal role in several signaling networks.

In alignment with recent research on other neurodegenerative diseases, these findings suggest that hyperactivation of innate immunity contributes to SMA pathology. This work not only provides compelling evidence that hyperactive innate immune signaling is a primary effect of SMN depletion, but it also suggests that the SMN complex plays a regulatory role in this process in vivo. In summary, immune dysfunction in SMA is a consequence of reduced SMN levels and is driven by cellular and molecular mechanisms that are conserved between insects and mammals.

LINC complex alterations are a key feature of sporadic and familial ALS/FTD.

Motor Neuron Disease

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder that primarily affects motor neurons, leading to progressive muscle weakness an...

[Recent research on home rehabilitation and nursing for spinal muscular atrophy].

Motor Neuron Disease

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder. With the emergence of disease-modifying therapies, the prognosis of...

Salivary α-Synuclein as a Candidate Biomarker of Parkinsonism in 22q11.2 Deletion Syndrome.

"Movement Disorders Clinical Practice

22q11.2 deletion syndrome (22q11.2DS) has been linked to an increased risk of early-onset Parkinson's disease. However, the pathophysiological mechanisms underlying parkinsonism remain poorly understood.

The objective is to investigate salivary total α-synuclein levels in 22q11.2DS patients with and without parkinsonian motor signs.

This cross-sectional study included 10 patients with 22q11.2DS with parkinsonism (Park+), ten 22q11.2DS patients without parkinsonism (Park-), and 10 age and sex-comparable healthy subjects (HS). Salivary and serum α-synuclein levels were measured using enzyme-linked immunosorbent assay.

Salivary total α-synuclein concentration was significantly lower in Park (+) patients than in Park (-) patients and HS (P = 0.007). In addition, salivary α-synuclein showed good accuracy in discriminating Park (+) from Park (-) patients (area under the curve = 0.86) and correlated with motor severity and cognitive impairment.

This exploratory study suggests that the parkinsonian phenotype of 22q11.2DS is associated with a reduced concentration of monomeric α-synuclein in biological fluids.

Dystonic Tremor: Time to Change.

"Movement Disorders Clinical Practice

The term dystonic tremor is being increasingly used in neurological publications despite uncertainties about its meaning. We provide here a historical reconstruction from its original introduction in 1984 to help distinguish dystonia from essential tremor.

A comprehensive Pubmed search of MeSH terms "dystonia", "tremor", and "essential tremor" provided the information base for reconstructing historical usage of the term "dystonic tremor".

Over the years, this expression was enriched of additional meanings and sided by companion descriptors, such as tremor associated with dystonia. Dystonic tremor has been considered characteristically coarse, jerky, irregular, directional and asymmetrical. These characteristics, however, are not included in the most recent definitions of tremor. The relationship between tremor and dystonia is not easy to untangle, as the two phenomena are often recognized in association. Tremor and dystonia experts have developed different visions of dystonic tremor that have been variably implemented. There are currently two independent consensus definitions, which are not coincident and imply different pathophysiological interpretations.

This historical reappraisal highlights that usage of the expression dystonic tremor has evolved over time to lose its original meaning. Notwithstanding inconsistencies of current definitions, its usage has steadily increased and it is time now to agree on an updated terminology.

Early Screening for the Parkinson Variant of Multiple System Atrophy: A 6-Item Score.

"Movement Disorders Clinical Practice

A 4-item score based on ≥2 features out of orthostatic hypotension, overactive bladder, urinary retention and postural instability was previously shown to early distinguish the Parkinson-variant of multiple system atrophy (MSA-P) from Parkinson's disease (PD) with 78% sensitivity and 86% specificity.

To replicate and improve the 4-item MSA-P score.

We retrospectively studied 161 patients with early parkinsonism [ie, ≤2 years disease duration or no postural instability, aged 64 (57; 68) years, 44% females] and a diagnosis of clinically established MSA-P (n = 38) or PD (n = 123) after ≥24 months follow-up.

The 4-item MSA-P score had a 92% sensitivity and 78% specificity for a final MSA-P diagnosis. By including dopaminergic responsiveness and postural deformities into a 6-item score (range: 0-6), reaching ≥3 points at early disease identified MSA-P patients with 89% sensitivity and 98% specificity.

The 6-item MSA-P score is a cost-effective tool to pinpoint individuals with early-stage MSA-P.

Adaptive immune changes associate with clinical progression of Alzheimer's disease.

Molecular Neurodegeneration

Alzheimer's disease (AD) is the most frequent cause of dementia. Recent evidence suggests the involvement of peripheral immune cells in the disease, but the underlying mechanisms remain unclear.

We comprehensively mapped peripheral immune changes in AD patients with mild cognitive impairment (MCI) or dementia compared to controls, using cytometry by time-of-flight (CyTOF).

We found an adaptive immune signature in AD, and specifically highlight the accumulation of PD1+ CD57+ CD8+ T effector memory cells re-expressing CD45RA in the MCI stage of AD. In addition, several innate and adaptive immune cell subsets correlated to cerebrospinal fluid (CSF) biomarkers of AD neuropathology and measures for cognitive decline. Intriguingly, subsets of memory T and B cells were negatively associated with CSF biomarkers for tau pathology, neurodegeneration and neuroinflammation in AD patients. Lastly, we established the influence of the APOE ε4 allele on peripheral immunity.

Our findings illustrate significant peripheral immune alterations associated with both early and late clinical stages of AD, emphasizing the necessity for further investigation into how these changes influence underlying brain pathology.

Real-time ultrasound-guided sacral plexus block combined with mild sedation for hemorrhoidectomy and hemorrhoidal artery ligation in a patient with amyotrophic lateral sclerosis: a case report.

Motor Neuron Disease

Patients with amyotrophic lateral sclerosis present perioperative challenges for clinical anesthesiologists for anesthesia-associated complications.

A 54-year-old Han woman with a 2-year history of amyotrophic lateral sclerosis was scheduled for hemorrhoidectomy and hemorrhoidal artery ligation. We performed real-time ultrasound-guided sacral plexus block with dexmedetomidine under standard monitoring. The anesthesia method met the surgical demands and avoided respiratory complications during the procedures. There was no neurological deterioration after the surgery and 3 months after, the patient was discharged.

Real-time ultrasound-guided sacral plexus block combined with mild sedation may be an effective and safe technique in patients with amyotrophic lateral sclerosis undergoing hemorrhoidectomy and hemorrhoidal artery ligation.

Regulation of human microglial gene expression and function via RNAase-H active antisense oligonucleotides in vivo in Alzheimer's disease.

Molecular Neurodegeneration

Microglia play important roles in maintaining brain homeostasis and neurodegeneration. The discovery of genetic variants in genes predominately or exclusively expressed in myeloid cells, such as Apolipoprotein E (APOE) and triggering receptor expressed on myeloid cells 2 (TREM2), as the strongest risk factors for Alzheimer's disease (AD) highlights the importance of microglial biology in the brain. The sequence, structure and function of several microglial proteins are poorly conserved across species, which has hampered the development of strategies aiming to modulate the expression of specific microglial genes. One way to target APOE and TREM2 is to modulate their expression using antisense oligonucleotides (ASOs).

In this study, we identified, produced, and tested novel, selective and potent ASOs for human APOE and TREM2. We used a combination of in vitro iPSC-microglia models, as well as microglial xenotransplanted mice to provide proof of activity in human microglial in vivo.

We proved their efficacy in human iPSC microglia in vitro, as well as their pharmacological activity in vivo in a xenografted microglia model. We demonstrate ASOs targeting human microglia can modify their transcriptional profile and their response to amyloid-β plaques in vivo in a model of AD.

This study is the first proof-of-concept that human microglial can be modulated using ASOs in a dose-dependent manner to manipulate microglia phenotypes and response to neurodegeneration in vivo.

LRRK2 G2019S impact on Parkinson disease; clinical phenotype and treatment in Tunisian patients.

Journal of Movement Disorders

LRRK2-G2019S is the most frequent mutation in North African Parkinson's disease (PD) patients.Data on its impact on disease progression and treatment response remains elusive.Therefore, we aimed to explore the clinical features,treatments,and complications through the disease course of PD Tunisian patients according to their LRRK2-G2019S profile.

Longitudinal retrospective study conducted in the department of Neurology,Razi University Hospital.We included clinically diagnosed PD patients according to the MDS criteria and reviewed their medical records for clinical,treatment, and neuropsychological assessments.LRRK2-G2019S mutation was screened among all cases using Sanger sequencing.The correlation of LRRK2-G2019S and the clinical PD features was then evaluated.

We included 393 PD patients with 41.5% of cases were mutated for LRRK2-G2019S. Those with mutation exhibited an earlier age of onset(p=0.017),and female-PD cases had a higher mutation frequency (p=0.008).Mutation carriers displayed distinct clinical features,with a higher frequency of postural instability gait difficulty (PIGD)forms(adjusted-p<0.001).Throughout the disease progression,carriers showed a faster annual progression in UPDRS-III scores (adjusted-p=0.009) and a significantly higher Levodopa Equivalent Dosevalues in later stages(1060.81 vs. 877.83 for 6-8 years).Motor complications such as dyskinesia (adjusted-p<0.001) and motor fluctuations(31.9% vs. 25.7%,adjusted-p<0.001) were more prevalent in carriers,particularly in later stages.LRRK2-G2019S carriers also exhibited a lower prevalence of non-motor symptoms including cognitive disordersfor episodic memory(adjusted-p<0.001),attention(adjusted-p<0.001),and dysexecutive disorders (adjusted-p=0.039),as well asneuropsychiatric symptoms and dysautonomic signs.

This study demonstrated the variability of clinical profile among Tunisian PD cases explained by the incomplete penetrance of LRRK2-G2019S that increases with age.Further studies with biomarker and disease progression data are necessary to improve PD management.

Profound hypoxemia and hypotension during posterior spinal fusion in a spinal muscular atrophy child with severe scoliosis: a case report.

Motor Neuron Disease

Anesthesia for spinal muscular atrophy (SMA) patients undergoing spinal deformity surgery is challenging. We report an unusual case of an SMA girl who developed severe intraoperative hypoxemia and hypotension during posterior spinal fusion related with surgical positioning.

A 13-yr-old girl diagnosed with SMA type 2, severe kyphoscoliosis and thoracic deformity was scheduled for elective posterior spinal fusion. She developed severe hypoxemia and profound hypotension intraoperatively in the prone position with surgical table tilted 45° to the right. Though transesophageal echocardiography (TEE) could not be performed due to limited mouth opening, her preoperative computed tomography revealed a severely distorted thoracic cavity with much reduced volume of the right side. A reasonable explanation was when the surgeons performed surgical procedure with the tilted surgical table, the pressure was directly put on the shortest diameter of the significantly deformed thoracic cavity, causing severe compression of the pulmonary artery, resulting in both hypoxemia and hypotension. The patient stabilized when the surgical table was tilted back and successfully went through the surgery in the leveled prone position.

Spinal fusion surgery is beneficial for SMA patients in preventing scoliosis progression and improving ventilation. However, severe scoliosis and thoracic deformities put them at risk of both hemodynamic and respiratory instability during surgical positioning. When advanced monitoring like TEE is not practical intraoperatively, preoperative imaging may help with differential diagnosis, and guide the surgical positioning to minimize mechanical compression of the thoracic cavity, thereby helping the patient complete the surgery safely.

Generation and characterization of monoclonal antibodies against pathologically phosphorylated TDP-43.

Motor Neuron Disease

Inclusions containing TAR DNA binding protein 43 (TDP-43) are a pathological hallmark of frontotemporal dementia (FTD) and amyotrophic lateral scle...