Electrodiagnosis in persons with amyotrophic lateral sclerosis

Enhanced Acute Muscle Activation in ALS Patients Following Liposomal Curcumin, Resveratrol, and Dutasteride Administration

Introduction: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by loss of electrical activity and motor control at the muscular level. Therapeutic alternatives, such as the polyphenolic antioxidants curcumin and resveratrol in liposome form, or the drug dutasteride, could be effective for muscular activity. Objective: To measure the acute change in electrical muscle activation after administration of a combination of curcumin in liposomal form, resveratrol, and dutasteride in patients with ALS. Materials and methods: Patients with bulbar and spinal ALS were selected and randomly distributed into an intervention group (IG), which received an oral combination of curcumin in liposomal form/resveratrol® and dutasteride for 2 months, and a control group (CG), which received a placebo. Electrical activity to determine basal muscle activation and fasciculations was measured before and after the intervention using surface electromyography of the biceps brachii (BB), triceps brachii (TB), rectus femoris (RF), and tibialis anterior (TA). Within comparisons of pre and post-muscular variations in each group were conducted. Results: Electrical basal activity increased only for the IG in the right (p = 0.05; g = -0.45) and left (p = 0.004; g = -0.74) hemibody muscles and also presented less variation among them after treatment in the IG. For fasciculations, there was an increase in the total activation of the upper muscles in the IG (p = 0.017; g = -0.86) and for the lower muscles in the CG (p = 0.037; g = -0.68). The pattern of muscle activation remained constant in the IG but experienced variations in the CG.

Preliminary Study on Wearable Smart Socks with Hydrogel Electrodes for Surface Electromyography-Based Muscle Activity Assessment

Surface electromyography (sEMG) is increasingly important for prevention, diagnosis, and rehabilitation in healthcare. The continuous monitoring of muscle electrical activity enables the detection of abnormal events, but existing sEMG systems often rely on disposable pre-gelled electrodes that can cause skin irritation and require precise placement by trained personnel. Wearable sEMG systems integrating textile electrodes have been proposed to improve usability; however, they often suffer from poor skin-electrode coupling, leading to higher impedance, motion artifacts, and reduced signal quality. To address these limitations, we propose a preliminary model of smart socks, integrating biocompatible hybrid polymer electrodes positioned over the target muscles. Compared with commercial Ag/AgCl electrodes, these hybrid electrodes ensure lower the skin-electrode impedance, enhancing signal acquisition (19.2 ± 3.1 kΩ vs. 27.8 ± 4.5 kΩ for Ag/AgCl electrodes). Moreover, to the best of our knowledge, this is the first wearable system incorporating hydrogel-based electrodes in a sock specifically designed for the analysis of lower limb muscles, which are crucial for evaluating conditions such as sarcopenia, fall risk, and gait anomalies. The system incorporates a lightweight, wireless commercial module for data pre-processing and transmission. sEMG signals from the Gastrocnemius and Tibialis muscles were analyzed, demonstrating a strong correlation (R = 0.87) between signals acquired with the smart socks and those obtained using commercial Ag/AgCl electrodes. Future studies will further validate its long-term performance under real-world conditions and with a larger dataset.

Muscle-specific Bet1L knockdown induces neuromuscular denervation, motor neuron degeneration, and motor dysfunction in a rat model of familial ALS

Amyotrophic lateral sclerosis (ALS) is a neuromuscular disease characterized by specific loss of motor neurons in the spinal cord and brain stem. Although ALS has historically been characterized as a motor neuron disease, there is evidence that motor neurons degenerate in a retrograde manner, beginning in the periphery at the neuromuscular junctions (NMJs) and skeletal muscle. We recently reported a vesicle trafficking protein Bet1L (Bet1 Golgi Vesicular Membrane Trafficking Protein Like) as a new molecule possibly linked to NMJ degeneration in ALS. In this study, we tested the hypothesis that Bet1L gene silencing in skeletal muscle could influence NMJ integrity, motor neuron function, and survival in a rat model of familial ALS (SOD1G93A transgenic). Small interfering RNA (siRNA) targeting the Bet1L gene was injected on a weekly basis into the hindlimb muscle of pre-symptomatic ALS and wild-type (WT) rats. After 3 weeks, intramuscular Bet1L siRNA injection significantly increased the number of denervated NMJs in the injected muscle. Bet1L knockdown decreased motor neuron size in the lumbar spinal cord, which innervated the siRNA-injected hindlimb. Impaired motor function was identified in the hindlimbs of Bet1L siRNA-injected rats. Notably, the effects of Bet1L knockdown on NMJ and motor neuron degeneration were more significant in ALS rats when compared to WT rats. Together, Bet1L knockdown induces denervation of NMJs, but also this knockdown accelerates the disease progression in ALS. Our results provide new evidence to support the potential roles of Bet1L as a key molecule in NMJ maintenance and ALS pathogenesis.

Artificial intelligence for screening and diagnosis of amyotrophic lateral sclerosis: a systematic review and meta-analysis

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a rare and fatal neurological disease that leads to progressive motor function degeneration. Diagnosing ALS is challenging due to the absence of a specific detection test. The use of artificial intelligence (AI) can assist in the investigation and treatment of ALS.

METHODS

We searched seven databases for literature on the application of AI in the early diagnosis and screening of ALS in humans. The findings were summarized using random-effects summary receiver operating characteristic curve. The risk of bias (RoB) analysis was carried out using QUADAS-2 or QUADAS-C tools.

RESULTS

In the 34 analyzed studies, a meta-prevalence of 47% for ALS was noted. For ALS detection, the pooled sensitivity of AI models was 94.3% (95% CI - 63.2% to 99.4%) with a pooled specificity of 98.9% (95% CI - 92.4% to 99.9%). For ALS classification, the pooled sensitivity of AI models was 90.9% (95% CI - 86.5% to 93.9%) with a pooled specificity of 92.3% (95% CI - 84.8% to 96.3%). Based on type of input for classification, the pooled sensitivity of AI models for gait, electromyography, and magnetic resonance signals was 91.2%, 92.6%, and 82.2%, respectively. The pooled specificity for gait, electromyography, and magnetic resonance signals was 94.1%, 96.5%, and 77.3%, respectively.

CONCLUSIONS

Although AI can play a significant role in the screening and diagnosis of ALS due to its high sensitivities and specificities, concerns remain regarding quality of evidence reported in the literature.

Animal Models of FUS-Proteinopathy: A Systematic Review

Mutations that disrupt the function of the DNA/RNA-binding protein FUS could cause amyotrophic lateral sclerosis (ALS) and other neurodegenerative diseases. One of the key features in ALS pathogenesis is the formation of insoluble protein aggregates containing aberrant isoforms of the FUS protein in the cytoplasm of upper and lower motor neurons. Reproduction of human pathology in animal models is the main tool for studying FUS-associated pathology and searching for potential therapeutic agents for ALS treatment. In this review, we provide a systematic analysis of the role of FUS protein in ALS pathogenesis and an overview of the results of modelling FUS-proteinopathy in animals.

Stathmin-2 loss leads to neurofilament-dependent axonal collapse driving motor and sensory denervation

The mRNA transcript of the human STMN2 gene, encoding for stathmin-2 protein (also called SCG10), is profoundly impacted by TAR DNA-binding protein 43 (TDP-43) loss of function. The latter is a hallmark of several neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). Using a combination of approaches, including transient antisense oligonucleotide-mediated suppression, sustained shRNA-induced depletion in aging mice, and germline deletion, we show that stathmin-2 has an important role in the establishment and maintenance of neurofilament-dependent axoplasmic organization that is critical for preserving the caliber and conduction velocity of myelinated large-diameter axons. Persistent stathmin-2 loss in adult mice results in pathologies found in ALS, including reduced interneurofilament spacing, axonal caliber collapse that drives tearing within outer myelin layers, diminished conduction velocity, progressive motor and sensory deficits, and muscle denervation. These findings reinforce restoration of stathmin-2 as an attractive therapeutic approach for ALS and other TDP-43-dependent neurodegenerative diseases.

How Knowledgeable Are Spine Surgeons Regarding EMG-NCS for Cervical Spine Conditions? An International Aospine Survey

STUDY DESIGN

Cross-sectional, international survey.

OBJECTIVES

To evaluate the knowledge of spine surgeons regarding the use of electromyography (EMG) and nerve conduction studies (NCS) for degenerative cervical spine conditions (DCC).

METHODS

All members of AO Spine International were emailed an anonymous survey to evaluate their clinical knowledge about the use of EMG and nerve conduction studies for DCC. Descriptive statistics were used to analyze the results, as well as to compare the answers among different groups of surgeons and assess demographic characteristics.

RESULTS

A total of 402 participants answered the survey, 91.79% were men from the 5 continents. There were 221 orthopedic surgeons (55.39%) and 171 neurosurgeons (42.86%), more than a half of them with a complete spinal fellowship (56.44%). The most common reasons that surgeons obtain the test is to differentiate a radiculopathy from a peripheral nerve compression (88.06%). As a group, the responding surgeons' knowledge regarding EMG-NCS was poor. Only 53.46% of surgeons correctly answered that EMG-NCS is unable to differentiate a C5 from a C6 radiculopathy. Only 23.47% of the surgeons knew that EMG-NCS are not able to diagnose a pre vs a post-fixed brachial plexus. Only 25% of the surgeons correctly answered a question regarding the test's ability to diagnose other neurological diseases.

CONCLUSIONS

We found that our respondents' knowledge regarding EMG-NCS for DCC was poor. Identifying the weak points of knowledge about EMG-NCS may help to educate surgeons on the indications for the test and the proper way to interpret the results.

Identification of dysregulated canonical pathways associated with pathogenesis and progression of Amyotrophic Lateral Sclerosis-An integrated bioinformatics approach

The mechanisms responsible for the pathogenesis and progression of Amyotrophic Lateral Sclerosis (ALS) remain poorly understood, making the diagnosis of ALS challenging. We aimed to find the novel gene biomarkers via computationally analyzing microarray expression studies, in three different cell lineages, namely myotube cells, astrocyte cells and oligodendrocyte cells. Microarray gene expression profiles were obtained and analyzed for three cell types: myotube cell lineage (GSE122261), astrocyte, and oligodendrocyte cell lineage (GSE87385). A comprehensive computational pipeline, tailored explicitly for microarray gene expression profiling studies, was devised to analyze the sample groups, wherein the myotube sample group comprised of six control (GSM3462697, GSM3462698, GSM3462699, GSM3462700, GSM3462701, GSM3462702) & six diseased (GSM3462691, GSM3462692, GSM3462693, GSM3462694, GSM3462695, GSM3462696) samples were considered. Similarly, for the astrocyte sample group two samples each for the control (GSM2330040, GSM2330042) and the diseased (GSM2330039, GSM2330041), and for the oligodendrocyte sample group, 2 control (GSM2330043, GSM2330045) samples and two diseased (GSM2330044, GSM2330046) samples were considered for the current study. The in-depth interaction of these DEGs was studied using MCODE and subjected to preliminary functional analysis using ClueGO/CluePedia plug-in. Qiagen's IPA software was employed for enrichment analysis, which generated the key canonical pathways and a list of potential biomarker molecules specific to each sample group. The preliminary analysis yielded 512 DEGs across all 3-sample groups, wherein 139 DEGs belonged to the myotube sample group, 216 DEGs for the astrocyte sample group, and 157 DEGs for the oligodendrocytes sample group. The data suggests growth hormone signaling and its activity, ErbB signaling pathway, and JAK/STAT signaling pathway are some of the pathways that are significantly dysregulated and play a crucial role in the development and progression of ALS. KISS1R and CSHL1 are potential genes that could act as diagnostic biomarkers in myotube cell types. Also, KRAS, TGFB2, JUN, and SMAD6 genes may be used as prognostic biomarkers to differentiate between early and late-stage ALS-diseased patients.

Structure and Function of the Mammalian Neuromuscular Junction

The mammalian neuromuscular junction (NMJ) comprises a presynaptic terminal, a postsynaptic receptor region on the muscle fiber (endplate), and the perisynaptic (terminal) Schwann cell. As with any synapse, the purpose of the NMJ is to transmit signals from the nervous system to muscle fibers. This neural control of muscle fibers is organized as motor units, which display distinct structural and functional phenotypes including differences in pre- and postsynaptic elements of NMJs. Motor units vary considerably in the frequency of their activation (both motor neuron discharge rate and duration/duty cycle), force generation, and susceptibility to fatigue. For earlier and more frequently recruited motor units, the structure and function of the activated NMJs must have high fidelity to ensure consistent activation and continued contractile response to sustain vital motor behaviors (e.g., breathing and postural balance). Similarly, for higher force less frequent behaviors (e.g., coughing and jumping), the structure and function of recruited NMJs must ensure short-term reliable activation but not activation sustained for a prolonged period in which fatigue may occur. The NMJ is highly plastic, changing structurally and functionally throughout the life span from embryonic development to old age. The NMJ also changes under pathological conditions including acute and chronic disease. Such neuroplasticity often varies across motor unit types. © 2022 American Physiological Society. Compr Physiol 12:1-36, 2022.

Motor neuron disease mimics in practice: a case series

In the majority of cases of motor neuron disease (MND), diagnosis is clinical and unambiguous. However, given the gravity of the diagnosis, it is crucial that treatable mimics are differentiated accurately. We present three cases referred to our clinic with possible MND with unusual features that led to an alternative diagnosis. (1) A middle-aged man with swallowing, then speech problems and foot drop. Tongue movements were slow and electromyography (EMG) showed fibrillations/positive sharp waves. Following investigation, a tonsillar tumour involving the tongue root was identified, and the foot drop improved, suggesting unrelated common peroneal nerve palsy (related to weight loss) or lumbar radiculopathy. (2) An elderly man presenting with progressive unilateral leg weakness and localised fasciculations on EMG. Following investigation, a high-grade brain glioma was diagnosed. (3) An elderly woman presenting with progressive quadriparesis over 18 months with fibrillations and chronic denervation on EMG. Symmetrical weakness and short duration response to immunotherapy led to further serological investigation and a diagnosis of anti-GD1a motor neuropathy. She was treated successfully with intravenous immunoglobulin, cyclophosphamide and rituximab and is now in remission.

T1 hyperintensity in the spinal cord: A diagnostic marker of amyotrophic lateral sclerosis?

Amyotrophic Lateral Sclerosis (ALS) is a rare, devastating motor neuron disease characterized by the degeneration of upper and lower motor neurons causing muscular weakness, paralysis, and eventual death. MRI plays a supportive role in the diagnosis; its primary role is to exclude other clinical mimics. Some of the imaging features associated with ALS include hypointense signal along the motor cortices on susceptibility or T2*-weighted imaging and hyperintensity along the corticospinal tracts (CST) within the cerebral hemispheres, brainstem, and spinal cord on the T2 weighted imaging. In this report, we discuss the value of T1 hyperintensity along the CST, especially in the spinal cord.

Evidence-based position paper on Physical and Rehabilitation Medicine practice for people with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron disease that affects both upper and lower motor neurons and is fatal in its course. This evidence-based position paper represents the official position of the UEMS PRM Section. The aim of the paper is to define the role of the physical and rehabilitation medicine (PRM) physician and PRM professional practice for people with ALS. A systematic review of the literature and a consensus procedure by means of a Delphi process have been performed involving the delegates of all European countries represented in the UEMS PRM Section. The systematic literature review is reported together with thirty-two recommendations resulting from the Delphi procedure. The responsibility of the PRM physician is functional assessment of persons with ALS and delivering the optimal and most effective PRM program of care. The rehabilitation program of patients with ALS should be delivered and monitored by the multiprofessional team, with the PRM physician as principal coordinator.

Genetic architecture of motor neuron diseases

Motor neuron diseases (MNDs) are rare and frequently fatal neurological disorders in which motor neurons within the brainstem and spinal cord regions slowly die. MNDs are primarily caused by genetic mutations, and > 100 different mutant genes in humans have been discovered thus far. Given the fact that many more MND-related genes have yet to be discovered, the growing body of genetic evidence has offered new insights into the diverse cellular and molecular mechanisms involved in the aetiology and pathogenesis of MNDs. This search may aid in the selection of potential candidate genes for future investigation and, eventually, may open the door to novel interventions to slow down disease progression. In this review paper, we have summarized detailed existing research findings of different MNDs, such as amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), spinal bulbar muscle atrophy (SBMA) and hereditary spastic paraplegia (HSP) in relation to their complex genetic architecture.

Motor unit number estimation versus compound muscle action potential in the evaluation of motor unit loss in amyotrophic lateral sclerosis

Introduction

Motor neuron loss is the primary pathologic feature of amyotrophic lateral sclerosis (ALS). An estimate of the number of surviving motor units (MUs) represents a direct measure of the disease state in ALS. The objective of the study is to compare MU number estimation (MUNE) using the multipoint stimulation method (MPS) and compound muscle action potentials (CMAP) amplitude in patients with ALS.

Methods

Twenty-eight patients with ALS with a disease duration of 3–48 months were studied. Nerve conduction study of the median, ulnar, tibial, common peroneal, and sural nerves were done. Besides, electromyography (EMG) of cranio-bulbar, cervical, thoracic and lumbosacral muscles, and MPS-MUNE.

Results

MUNE is decreased in patients with ALS. MUNE was positively correlated with CMAP amplitude, medical research council (MRC) scale, and ALS functional rating scale (ALS-FRS). On the contrary, MUNE was negatively correlated with MUAP duration. Case detection by the MUNE methods was high as compared to that of CMAP amplitude.

Conclusions

MUNE is highly specific and more sensitive than CMAP amplitude in detecting the neurophysiologic abnormalities in patients with ALS. Case detection by MUNE is three times more than CMAP amplitudes. The rate of decline of motor units using the MPS-MUNE is more sensitive than the MRC score and ALSFRS-R when expressed as the percentage change from baseline.

Awaji criteria for the diagnosis of amyotrophic lateral sclerosis in Hanoi, Vietnam

The aim of the article was to evaluate the role of electromyography and the value of Awaji criteria for the diagnosis of ALS in the early stage. The study involves 48 patients (27 male and 21 females from 41 to 84 years old) who went to Bach Mai Hospital and Dong Do Clinic in Hanoi and were diagnosed with ALS according to Awaji criteria. All patients underwent clinical examination for ALS. The patients were examined for nerve conduction (motor and sensory conduction) using needle electromyography (EMG). Upper motor neuron (UMN) signs and lower motor neuron (LMN) signs were most common in the cervical region (89.58%), the lumbosacral region (70.83%), and the bulbar region (56.25%). The sensory nerve conduction was normal. The spontaneous activities (fasciculation, fibrillation, positive wave) accounted for more than 50% in all 4 regions: bulbar, cervical, thoracic, and lumbosacral regions. The abnormality of both clinical and electrodiagnosis was seen in the cervical region (87.5%) and lumbosacral one (70.83%) while the bulbar region and thoracic one usually had abnormal electrodiagnosis before clinical. There were 60.42% of patients with "definite ALS" by Awaji criteria. It allowed to make an earlier diagnosis cause the sensitivity of Awaji criteria (93.75%) was higher than the revised El Escorial criteria (85.42%) (p < 0.05). The needle EMG makes it possible to detect the early-stage symptoms of ALS in a situation where there are no clinical manifestations, especially in bulbar and thoracic regions.

Circulating cell-free DNA as potential diagnostic tools for amyotrophic lateral sclerosis

DNA methylation has garnered much attention in recent years for its diagnostic potential in multiple conditions including cancer and neurodegenerative diseases. Conversely, advances regarding the potential diagnostic relevance of DNA methylation status have been sparse in the field of amyotrophic lateral sclerosis (ALS) even though patients diagnosed with this condition would significantly benefit from improved molecular assays aimed at furthering the current diagnostic and therapeutic options available. This review will provide an overview of the current diagnostic approaches available for ALS diagnosis and discuss the potential clinical usefulness of DNA methylation. We will also present examples of DNA methylation as a diagnostic tool in various types of cancer and neurodegenerative conditions and expand on how circulating cfDNA methylation may be leveraged for the early detection of ALS. In general, this article will reinforce the importance of cfDNA methylation as diagnostic tools and will further highlight its clinical relevance for persons diagnosed with ALS.

Chronic Pharmacological Increase of Neuronal Activity Improves Sensory-Motor Dysfunction in Spinal Muscular Atrophy Mice

Dysfunction of neuronal circuits is an important determinant of neurodegenerative diseases. Synaptic dysfunction, death, and intrinsic activity of neurons are thought to contribute to the demise of normal behavior in the disease state. However, the interplay between these major pathogenic events during disease progression is poorly understood. Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by a deficiency in the ubiquitously expressed protein SMN and is characterized by motor neuron death, skeletal muscle atrophy, as well as dysfunction and loss of both central and peripheral excitatory synapses. These disease hallmarks result in an overall reduction of neuronal activity in the spinal sensory-motor circuit. Here, we show that increasing neuronal activity by chronic treatment with the FDA-approved potassium channel blocker 4-aminopyridine (4-AP) improves motor behavior in both sexes of a severe mouse model of SMA. 4-AP restores neurotransmission and number of proprioceptive synapses and neuromuscular junctions (NMJs), while having no effects on motor neuron death. In addition, 4-AP treatment with pharmacological inhibition of p53-dependent motor neuron death results in additive effects, leading to full correction of sensory-motor circuit pathology and enhanced phenotypic benefit in SMA mice. Our in vivo study reveals that 4-AP-induced increase of neuronal activity restores synaptic connectivity and function in the sensory-motor circuit to improve the SMA motor phenotype.SIGNIFICANCE STATEMENT Spinal muscular atrophy (SMA) is a neurodegenerative disease, characterized by synaptic loss, motor neuron death, and reduced neuronal activity in spinal sensory-motor circuits. However, whether these are parallel or dependent events is unclear. We show here that long-term increase of neuronal activity by the FDA-approved drug 4-aminopyridine (4-AP) rescues the number and function of central and peripheral synapses in a SMA mouse model, resulting in an improvement of the sensory-motor circuit and motor behavior. Combinatorial treatment of pharmacological inhibition of p53, which is responsible for motor neuron death and 4-AP, results in additive beneficial effects on the sensory-motor circuit in SMA. Thus, neuronal activity restores synaptic connections and improves significantly the severe SMA phenotype.

Medical cost and healthcare utilization of amyotrophic lateral sclerosis in China: A cohort study based on hospital data from 2015 to 2018

Amyotrophic lateral sclerosis (ALS), a specific neurodegenerative disease, imposed increased economic and utilizations burden on the healthcare system, especially with the progress of the diseases severity. However, the economic burden on Chinese ALS patients remained unclear. This study therefore was aimed to investigate medical cost and healthcare utilization for Chinese ALS patients.Longitudinal health data of over 20 million individuals, including military personnel and civilians, was collected from all Chinese military hospitals. We identified 480 patients with a first major diagnosis for ALS from 2015 to 2018, while matched 400 controlled patients on age, gender, ethnic group, geographic region, length of stay, year of diagnosis and comorbidity. Their medical cost and healthcare utilizations were then measured 1 year before, and 1 year after ALS diagnosis.The median annual medical cost of ALS patients was about 2-fold higher, 17,087 CNY during the index year than 1 year before, 7859 CNY. The highest increase in utilizations may account for medical costs on ALS patients, which was represented by hospitalizations (Odd Ratio (OR) = 4.26, 95% confidence interval (CI) 3.52, 5.15), electromyography (OR = 4.14, 95% CI 2.37, 7.22), nerve conduction velocity (OR = 3.26, 95% CI 2.23, 4.77).This study is the first one reporting direct economic burden on Chinese ALS patients. Efforts should be made to develop cost-effective diagnostic tools in order that sources of medical cost were more effectively allocated, and this disease was detected earlier.

Exciting Complexity: The Role of Motor Circuit Elements in ALS Pathophysiology

Amyotrophic lateral sclerosis (ALS) is a fatal disease, characterized by the degeneration of both upper and lower motor neurons. Despite decades of research, we still to date lack a cure or disease modifying treatment, emphasizing the need for a much-improved insight into disease mechanisms and cell type vulnerability. Altered neuronal excitability is a common phenomenon reported in ALS patients, as well as in animal models of the disease, but the cellular and circuit processes involved, as well as the causal relevance of those observations to molecular alterations and final cell death, remain poorly understood. Here, we review evidence from clinical studies, cell type-specific electrophysiology, genetic manipulations and molecular characterizations in animal models and culture experiments, which argue for a causal involvement of complex alterations of structure, function and connectivity of different neuronal subtypes within the cortical and spinal cord motor circuitries. We also summarize the current knowledge regarding the detrimental role of astrocytes and reassess the frequently proposed hypothesis of glutamate-mediated excitotoxicity with respect to changes in neuronal excitability. Together, these findings suggest multifaceted cell type-, brain area- and disease stage- specific disturbances of the excitation/inhibition balance as a cardinal aspect of ALS pathophysiology.

Ultrasound versus electromyography for the detection of fasciculation in amyotrophic lateral sclerosis: systematic review and meta-analysis

The objective of this study was to determine the diagnostic accuracy of ultrasound and electromyography for the detection of fasciculation in patients with amyotrophic lateral sclerosis and to compare detection rates between the two methods. By searching the Cochrane Library, MEDLINE, Excerpta Medica, and Latin-American and Caribbean Health Sciences Literature databases, we identified studies evaluating the diagnostic accuracy and fasciculation detection rates of ultrasound and electromyography. The Quality Assessment of Diagnostic Accuracy Studies, version 2, and RTI item bank tools were used for the evaluation of methodological quality. Ultrasound, for 10 s or 30 s, had a higher detection rate than did electromyography in all muscles evaluated. The overall detection rate (in patients) did not differ significantly between ultrasound for 10 s and ultrasound for 30 s. The accuracy of ultrasound for 10 s was 70% in muscles and 85% in patients. The accuracy of ultrasound for 30 s was 82% in patients. Ultrasound provided detection rates superior to those achieved with electromyography, independent of the examination time and muscles evaluated.

Extracellular vesicles and their diagnostic potential in amyotrophic lateral sclerosis

Extracellular vesicles, small reservoirs that carry various biomolecules, have gained significant interest from the clinical field in recent years based on the diagnostic, therapeutic and prognostic possibilities they offer. While information abound regarding the clinical potential of such vesicles in diverse conditions, the information demonstrating their likely importance in amyotrophic lateral sclerosis (ALS) is more limited. This review will thus provide a brief introduction to extracellular vesicles, highlight their diagnostic significance in various diseases with a focus on ALS and explore additional applications of extracellular vesicles in the medical field. Overall, this work sheds further light on the clinical importance of extracellular vesicles in diagnostic applications as well as supports the need to better characterize their roles and signatures in patients diagnosed with ALS.

Diagnostic Challenge and Neuromuscular Junction Contribution to ALS Pathogenesis

Amyotrophic lateral sclerosis (ALS) represents the major adult-onset motor neuron disease. Both human and animal studies reveal the critical implication of muscle and neuromuscular junctions (NMJs) in the initial phase of this disease. Despite the common efforts, ALS diagnosis remains particularly challenging since many other disorders can overlap yielding similar clinical phenotypic features. A combination of further research on the NMJ parameters that are specific for this disease and laboratory tests are crucial for the early determination of specific changes in the muscle, as well as in motor neuron and the prediction of ALS progression. Also, it could provide a powerful tool in the discrimination of particular ALS and ALS-mimic cases and increase the efficacy of therapeutic treatments.

Epidemiology and diagnostic process of amyotrophic lateral sclerosis as distinct from myelopathy: 5-year cohort study of whole-population in South Korea

OBJECTIVE

To investigate the incidence, prevalence, and demographic factors of all amyotrophic lateral sclerosis (ALS) patients diagnosed in South Korea from 2011 to 2015, and to analyze cases misdiagnosed as myelopathy.

METHODS

The whole population registered under the Korean National Health Insurance Service (KNHIS) was applied. All 4551 patients who were registered as having ALS code from 2011 to 2015 were included. For all ALS patients, the incidence, prevalence, and demographic factors were assessed. Trends of diagnosis for myelopathy, and surgery prior to confirmation of ALS diagnosis were identified.

RESULTS

When the whole 48,135,715 KNHIS population enrolled in 2015, the incidence of ALS in 2015 was estimated to be 1.68 per 100,000 person-years, and the prevalence was 6.49 per 100,000 persons. Life expectancy of ALS can be calculated as 3.9 years after the diagnosis, and the mean age of diagnosis was 59.5 ± 13.1. A total of 1902 patients diagnosed with myelopathy before a diagnosis of ALS accounted for 0.13% of all myelopathy patients, and 41.8% of all ALS patients. It took an average of 471.7 d to confirm a diagnosis of ALS after the myelopathy diagnosis. Among the patients finally diagnosed with ALS, more patients underwent surgery for myelopathy (n = 263, 13.8%) than among patients who were diagnosed with myelopathy alone, and underwent surgery (n = 141,148, 9.8%).

CONCLUSIONS

This whole-population nationwide demographic study confirmed the data from previous studies. Clinicians should consider the possibility of ALS when making a myelopathy diagnosis, especially if the symptoms are sufficiently severe to require surgery.

Clinical Mimickers of Amyotrophic Lateral Sclerosis-Conditions We Cannot Afford to Miss

Giving a diagnosis of amyotrophic lateral sclerosis to a patient is akin to handing out a death certificate. However, not all patients presenting with the classical dysphagia, wasting, and weakness may have motor neuron diseases. In these cases, it is extremely important not to miss little cues which can suggest an alternative diagnosis and in many cases a lease of life in terms of a treatment option. In this review, we consider some clinical scenarios that can present with the same symptom complex as diseases involving motor neurons but have a different anatomical or etiopathological basis and in many cases even a therapeutic option.

EMG indications and findings in a sub-Saharan African neurorehabilitation center

•

Little is published about the usage of electro-diagnostic procedures in sub Saharan Africa.

•

We report the indications and findings in a sub-Saharan African neurorehabilitation center.

•

Polyneuropathy and entrapment neuropathy were the most common reasons for electrodiagnostic requests.

Objective

This study aims to assess the frequency and indication for electrodiagnostic referrals as well as to summarize the findings from the procedure at a neurorehabilitation center in Ibadan, Nigeria.

Methods

This is a retrospective cross-sectional study. Data from referrals to Blossom Medical Centre/World Federation for Neurorehabilitation (BMC/WFNR) center, Ibadan, Nigeria, from April 2014 to December 2016 were collated and analyzed.

Results

Sixty referrals were received during the period of evaluation. Neurologists referred most of the patients (47; 71.7%). Disorders of the peripheral nerves were the most frequent reasons for electromyography (EMG), and they were the most common electrodiagnosis with better classified into axonal and demyelinating types. The overall congruence between the suspected diagnosis and final diagnosis was 58.3%. Requests by neurologists were significantly more appropriate than those by other specialists (p value = 0.02).

Conclusion

Polyneuropathy, entrapment neuropathy, and disorders of the motor nerve root and plexus were the most common reasons for electrodiagnostic requests, and the majority of the referrals were from neurologists.

Significance

EMG has changed the approach towards the diagnosis and management of neuromuscular disorders in Nigeria. It is hoped that with more neurophysiology education in this environment, neurophysiological practice will become widely available.

Biomarkers of Amyotrophic Lateral Sclerosis: Current Status and Interest of Oxysterols and Phytosterols

Amyotrophic lateral sclerosis (ALS) is a non-demyelinating neurodegenerative disease in adults with motor disorders. Two forms exist: a sporadic form (90% of cases) and a family form due to mutations in more than 20 genes including the Superoxide dismutase 1, TAR DNA Binding Protein, Fused in Sarcoma, chromosome 9 open reading frame 72 and VAPB genes. The mechanisms associated with this pathology are beginning to be known: oxidative stress, glutamate excitotoxicity, protein aggregation, reticulum endoplasmic stress, neuroinflammation, alteration of RNA metabolism. In various neurodegenerative diseases, such as Alzheimer's disease or multiple sclerosis, the involvement of lipids is increasingly suggested based on lipid metabolism modifications. With regard to ALS, research has also focused on the possible involvement of lipids. Lipid involvement was suggested for clinical arguments where changes in cholesterol and LDL/HDL levels were reported with, however, differences in positivity between studies. Since lipids are involved in the membrane structure and certain signaling pathways, it may be considered to look for oxysterols, mainly 25-hydroxycholesterol and its metabolites involved in immune response, or phytosterols to find suitable biomarkers for this pathology.

Shortcomings in the Current Amyotrophic Lateral Sclerosis Trials and Potential Solutions for Improvement

Amyotrophic lateral sclerosis (ALS) is a clinically progressive neurodegenerative syndrome predominantly affecting motor neurons and their associated tracts. Riluzole and edaravone are the only FDA certified drugs for treating ALS. Over the past two decades, almost all clinical trials aiming to develop a successful therapeutic strategy for this disease have failed. Genetic complexity, inadequate animal models, poor clinical trial design, lack of sensitive biomarkers, and diagnostic delays are some of the potential reasons limiting any significant development in ALS clinical trials. In this review, we have outlined the possible reasons for failure of ALS clinical trials, addressed the factors limiting timely diagnosis, and suggested possible solutions for future considerations for each of the shortcomings.

Association Between Rectus Abdominis Denervation and Ventilation Dysfunction in Patients with Amyotrophic Lateral Sclerosis

Background:

Spontaneous potentials in electromyography (EMG) of paraspinal muscles are associated with diaphragm denervation and, therefore, poor respiratory function in amyotrophic lateral sclerosis (ALS) is understandable. EMG changes in the rectus abdominis (RA) display an effect similar to those in paraspinal muscles with respect to the function of lower motor neurons in the thoracic spinal cord. The RA denervation was examined to determine its association with ventilation dysfunction in ALS.

Methods:

We collected the clinical data of 128 patients with sporadic ALS in Department of Neurology of Peking University Third Hospital from 2009 to 2013. EMG, Revised ALS Functional Rating Scale (ALSFRS-R) and forced vital capacity (FVC) were performed in all patients and the differences in the EMG changes in RA between those with and without FVC ≥ 80% were analysed.

Results:

The mean FVC value was 83.4% ± 17.1% (range: 45%–131%) of the predicted value. A total of 79 patients displayed FVC ≥80%, and 49 patients displayed FVC <80%. Compared with the patients displaying a normal FVC (60/79, 75.9%), spontaneous activity in RA was significantly different among those patients displaying an FVC <80% (47/49, 95.9%). In addition, spontaneous potentials in RA were more frequently detected in patients exhibiting dyspnea (32/33, 97.0%) than in patients without dyspnea (75/95, 78.9%).

Conclusion:

Spontaneous potentials in RA are associated with ventilation dysfunction and dyspnea in ALS patients.

Molecular diagnostics of neurodegenerative disorders

Molecular diagnostics provide a powerful method to detect and diagnose various neurological diseases such as Alzheimer's and Parkinson's disease. The confirmation of such diagnosis allows early detection and subsequent medical counseling that help specific patients to undergo clinically important drug trials. This provides a medical pathway to have better insight of neurogenesis and eventual cure of the neurodegenerative diseases. In this short review, we present recent advances in molecular diagnostics especially biomarkers and imaging spectroscopy for neurological diseases. We describe advances made in Alzheimer's disease (AD), Parkinson's disease (PD), Amyotrophic lateral sclerosis (ALS) and Huntington's disease (HD), and finally present a perspective on the future directions to provide a framework for further developments and refinements of molecular diagnostics to combat neurodegenerative disorders.

Endomicroscopy and electromyography of neuromuscular junctions in situ

Objective

Electromyography (EMG) is used routinely to diagnose neuromuscular dysfunction in a wide range of peripheral neuropathies, myopathies, and neuromuscular degenerative diseases including motor neuron diseases such as amyotrophic lateral sclerosis (ALS). Definitive neurological diagnosis may also be indicated by the analysis of pathological neuromuscular innervation in motor-point biopsies. Our objective in this study was to preempt motor-point biopsy by combining live imaging with electrophysiological analysis of slow degeneration of neuromuscular junctions (NMJs) in vivo.

Methods

We combined conventional needle electromyography with fiber-optic confocal endomicroscopy (CEM), using an integrated hand-held, 1.5-mm-diameter probe. We utilized as a test bed, various axotomized muscles in the hind limbs of anaesthetized, double-homozygous thy1.2YFP16: Wld^S mice, which coexpress the Wallerian-degeneration Slow (Wld^S) protein and yellow fluorescent protein (YFP) in motor neurons. We also tested exogenous vital stains, including Alexa488-α-bungarotoxin; the styryl pyridinium dye 4-Di-2-Asp; and a GFP conjugate of botulinum toxin Type A heavy chain (GFP-HcBoNT/A).

Results

We show that an integrated EMG/CEM probe is effective in longitudinal evaluation of functional and morphological changes that take place over a 7-day period during axotomy-induced, slow neuromuscular synaptic degeneration. EMG amplitude declined in parallel with overt degeneration of motor nerve terminals. EMG/CEM was safe and effective when nerve terminals and motor endplates were selectively stained with vital dyes.

Interpretation

Our findings constitute proof-of-concept, based on live imaging in an animal model, that combining EMG/CEM may be useful as a minimally invasive precursor or alternative to motor-point biopsy in neurological diagnosis and for monitoring local administration of potential therapeutics.

Blood biomarkers for amyotrophic lateral sclerosis: myth or reality?

Amyotrophic lateral sclerosis (ALS) is a fatal condition primarily characterized by the selective loss of upper and lower motor neurons. At present, the diagnosis and monitoring of ALS is based on clinical examination, electrophysiological findings, medical history, and exclusion of confounding disorders. There is therefore an undeniable need for molecular biomarkers that could give reliable information on the onset and progression of ALS in clinical practice and therapeutic trials. From a practical point of view, blood offers a series of advantages, including easy handling and multiple testing at a low cost, that make it an ideal source of biomarkers. In this review, we revisited the findings of many studies that investigated the presence of systemic changes at the molecular and cellular level in patients with ALS. The results of these studies reflect the diversity in the pathological mechanisms contributing to disease (e.g., excitotoxicity, oxidative stress, neuroinflammation, metabolic dysfunction, and neurodegeneration, among others) and provide relatively successful evidence of the usefulness of a wide-ranging panel of molecules as potential biomarkers. More studies, hopefully internationally coordinated, would be needed, however, to translate the application of these biomarkers into benefit for patients.

LRP4 antibodies in serum and CSF from amyotrophic lateral sclerosis patients

Objective

Amyotrophic lateral sclerosis (ALS) and myasthenia gravis (MG) are caused, respectively, by motor neuron degeneration and neuromuscular junction (NMJ) dysfunction. The membrane protein LRP4 is crucial in the development and function of motor neurons and NMJs and LRP4 autoantibodies have been recently detected in some MG patients. Because of the critical role in motor neuron function we searched for LRP4 antibodies in ALS patients.

Methods

We developed a cell-based assay and a radioimmunoassay and with these we studied the sera from 104 ALS patients.

Results

LRP4 autoantibodies were detected in sera from 24/104 (23.4%) ALS patients from Greece (12/51) and Italy (12/53), but only in 5/138 (3.6%) sera from patients with other neurological diseases and 0/40 sera from healthy controls. The presence of LRP4 autoantibodies in five of six tested patients was persistent for at least 10 months. Cerebrospinal fluid samples from six of seven tested LRP4 antibody-seropositive ALS patients were also positive. No autoantibodies to other MG autoantigens (AChR and MuSK) were detected in ALS patients. No differences in clinical pattern were seen between ALS patients with or without LRP4 antibodies.

Conclusions

We infer that LRP4 autoantibodies are involved in patients with neurological manifestations affecting LRP4-containing tissues and are found more frequently in ALS patients than MG patients. LRP4 antibodies may have a direct pathogenic activity in ALS by participating in the denervation process.