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Sample records for las alteraciones neuromusculares

  1. Neuromuscular Disorders

    MedlinePlus

    Neuromuscular disorders affect the nerves that control your voluntary muscles. Voluntary muscles are the ones you can control, like ... and your ability to breathe. Examples of neuromuscular disorders include Amyotrophic lateral sclerosis Multiple sclerosis Myasthenia gravis ...

  2. Neuromuscular Scoliosis

    MedlinePlus

    ... degree of neuromuscular involvement. Diagnosis Incidence of Scoliosis Cerebral palsy (2 limbs involved) 25% Myelodysplasia (lower lumbar) 60% Spinal muscle atrophy 67% Friedreich ataxia 80% Cerebral palsy (4 limbs involved) 80% Duchenne muscular dystrophy 90% ...

  3. Neuromuscular block

    PubMed Central

    Bowman, W C

    2006-01-01

    Descriptions of the South American arrow poisons known as curares were reported by explorers in the 16th century, and their site of action in producing neuromuscular block was determined by Claude Bernard in the mid-19th century. Tubocurarine, the most important curare alkaloid, played a large part in experiments to determine the role of acetylcholine in neuromuscular transmission, but it was not until after 1943 that neuromuscular blocking drugs became established as muscle relaxants for use during surgical anaesthesia. Tubocurarine causes a number of unwanted effects, and there have been many attempts to replace it. The available drugs fall into two main categories: the depolarising blocking drugs and the nondepolarising blocking drugs. The former act by complex mixed actions and are now obsolete with the exception of suxamethonium, the rapid onset and brief duration of action of which remain useful for intubation at the start of surgical anaesthesia. The nondepolarising blocking drugs are reversible acetylcholine receptor antagonists. The main ones are the atracurium group, which possess a built-in self-destruct mechanism that makes them especially useful in kidney or liver failure, and the vecuronium group, which are especially free from unwanted side effects. Of this latter group, the compound rocuronium is of especial interest because its rapid onset of action allows it to be used for intubation, and there is promise that its duration of action may be rapidly terminated by a novel antagonist, a particular cyclodextrin, that chelates the drug, thereby removing it from the acetylcholine receptors. PMID:16402115

  4. Neuromuscular complications in cancer.

    PubMed

    Grisold, W; Grisold, A; Löscher, W N

    2016-08-15

    Cancer is becoming a treatable and even often curable disease. The neuromuscular system can be affected by direct tumor invasion or metastasis, neuroendocrine, metabolic, dysimmune/inflammatory, infections and toxic as well as paraneoplastic conditions. Due to the nature of cancer treatment, which frequently is based on a DNA damaging mechanism, treatment related toxic side effects are frequent and the correct identification of the causative mechanism is necessary to initiate the proper treatment. The peripheral nervous system is conventionally divided into nerve roots, the proximal nerves and plexus, the peripheral nerves (mono- and polyneuropathies), the site of neuromuscular transmission and muscle. This review is based on the anatomic distribution of the peripheral nervous system, divided into cranial nerves (CN), motor neuron (MND), nerve roots, plexus, peripheral nerve, the neuromuscular junction and muscle. The various etiologies of neuromuscular complications - neoplastic, surgical and mechanic, toxic, metabolic, endocrine, and paraneoplastic/immune - are discussed separately for each part of the peripheral nervous system. PMID:27423586

  5. Electrodiagnosis in neuromuscular disease.

    PubMed

    Lipa, Bethany M; Han, Jay J

    2012-08-01

    Electromyography (EMG) is an important diagnostic tool for the assessment of individuals with various neuromuscular diseases. It should be an extension of a thorough history and physical examination. Some prototypical characteristics and findings of EMG and nerve conduction studies are discussed; however, a more thorough discussion can be found in the textbooks and resources sited in the article. With an increase in molecular genetic diagnostics, EMG continues to play an important role in the diagnosis and management of patients with neuromuscular diseases and also provides a cost-effective diagnostic workup before ordering a battery of costly genetic tests.

  6. Electrodiagnosis in neuromuscular disease.

    PubMed

    Lipa, Bethany M; Han, Jay J

    2012-08-01

    Electromyography (EMG) is an important diagnostic tool for the assessment of individuals with various neuromuscular diseases. It should be an extension of a thorough history and physical examination. Some prototypical characteristics and findings of EMG and nerve conduction studies are discussed; however, a more thorough discussion can be found in the textbooks and resources sited in the article. With an increase in molecular genetic diagnostics, EMG continues to play an important role in the diagnosis and management of patients with neuromuscular diseases and also provides a cost-effective diagnostic workup before ordering a battery of costly genetic tests. PMID:22938876

  7. Genetics and Neuromuscular Diseases

    MedlinePlus

    ... Neuromuscular Diseases • ©2011 MDA cell nucleus cell chromosomes DNA Genes are made of DNA, which is stored on chromo- somes in each ... particular protein. The effects of a mutation in DNA in a person depend on many fac- tors, ...

  8. Biotherapies of neuromuscular disorders.

    PubMed

    Briand, J-F; Roy, M-O; Mourlane, F; André, C; Loux, N; Rougeau, C; Toursel, T; Braun, S

    2014-12-01

    This review focuses on the most recent data on biotherapeutic approaches, using DNA, RNA, recombinant proteins, or cells as therapeutic tools or targets for the treatment of neuromuscular diseases. Many of these novel technologies have now reached the clinical stage and have or are about to move to the market. Others, like genome editing are still in an early stage but hold great promise.

  9. Computational Models for Neuromuscular Function

    PubMed Central

    Valero-Cuevas, Francisco J.; Hoffmann, Heiko; Kurse, Manish U.; Kutch, Jason J.; Theodorou, Evangelos A.

    2011-01-01

    Computational models of the neuromuscular system hold the potential to allow us to reach a deeper understanding of neuromuscular function and clinical rehabilitation by complementing experimentation. By serving as a means to distill and explore specific hypotheses, computational models emerge from prior experimental data and motivate future experimental work. Here we review computational tools used to understand neuromuscular function including musculoskeletal modeling, machine learning, control theory, and statistical model analysis. We conclude that these tools, when used in combination, have the potential to further our understanding of neuromuscular function by serving as a rigorous means to test scientific hypotheses in ways that complement and leverage experimental data. PMID:21687779

  10. Neuromuscular complications of acromegaly.

    PubMed

    Pickett, J B; Layzer, R B; Levin, S R; Scheider, V; Campbell, M J; Sumner, A J

    1975-07-01

    Seventeen consecutive acromegalic patients were evaluated for evidence of neuromuscular dysfunction and followed for 1 year after hypophysectomy. Before treatment, four patients had both a myopathy and the carpal tunnel syndrome, five had myopathy alone, four had carpal tunnel syndrome alone, and four had neither. The myopathy was caracterized by mild, strictly promixal weakness and flabbiness of muscles; electromyography revealed typical myopathic abnormalities, but serum enzymes and muscle biopsy usually were normal. The presence of myopathy or the carpal tunnel syndrrome could not be correlated with the magnitude of growth hormone elevation or any secondary endocrine derangement, but myopathy was associated with a longer duration of acromegaly. Carpal tunnel symptoms usually improved in the first 6 weeks after hypophysectomy, while myopathy improved more slowly and sometimes was detectable 1 year later.

  11. Neuromuscular disease classification system

    NASA Astrophysics Data System (ADS)

    Sáez, Aurora; Acha, Begoña; Montero-Sánchez, Adoración; Rivas, Eloy; Escudero, Luis M.; Serrano, Carmen

    2013-06-01

    Diagnosis of neuromuscular diseases is based on subjective visual assessment of biopsies from patients by the pathologist specialist. A system for objective analysis and classification of muscular dystrophies and neurogenic atrophies through muscle biopsy images of fluorescence microscopy is presented. The procedure starts with an accurate segmentation of the muscle fibers using mathematical morphology and a watershed transform. A feature extraction step is carried out in two parts: 24 features that pathologists take into account to diagnose the diseases and 58 structural features that the human eye cannot see, based on the assumption that the biopsy is considered as a graph, where the nodes are represented by each fiber, and two nodes are connected if two fibers are adjacent. A feature selection using sequential forward selection and sequential backward selection methods, a classification using a Fuzzy ARTMAP neural network, and a study of grading the severity are performed on these two sets of features. A database consisting of 91 images was used: 71 images for the training step and 20 as the test. A classification error of 0% was obtained. It is concluded that the addition of features undetectable by the human visual inspection improves the categorization of atrophic patterns.

  12. Neuromuscular disease classification system.

    PubMed

    Sáez, Aurora; Acha, Begoña; Montero-Sánchez, Adoración; Rivas, Eloy; Escudero, Luis M; Serrano, Carmen

    2013-06-01

    Diagnosis of neuromuscular diseases is based on subjective visual assessment of biopsies from patients by the pathologist specialist. A system for objective analysis and classification of muscular dystrophies and neurogenic atrophies through muscle biopsy images of fluorescence microscopy is presented. The procedure starts with an accurate segmentation of the muscle fibers using mathematical morphology and a watershed transform. A feature extraction step is carried out in two parts: 24 features that pathologists take into account to diagnose the diseases and 58 structural features that the human eye cannot see, based on the assumption that the biopsy is considered as a graph, where the nodes are represented by each fiber, and two nodes are connected if two fibers are adjacent. A feature selection using sequential forward selection and sequential backward selection methods, a classification using a Fuzzy ARTMAP neural network, and a study of grading the severity are performed on these two sets of features. A database consisting of 91 images was used: 71 images for the training step and 20 as the test. A classification error of 0% was obtained. It is concluded that the addition of features undetectable by the human visual inspection improves the categorization of atrophic patterns. PMID:23804164

  13. Neuromuscular ultrasound of cranial nerves.

    PubMed

    Tawfik, Eman A; Walker, Francis O; Cartwright, Michael S

    2015-04-01

    Ultrasound of cranial nerves is a novel subdomain of neuromuscular ultrasound (NMUS) which may provide additional value in the assessment of cranial nerves in different neuromuscular disorders. Whilst NMUS of peripheral nerves has been studied, NMUS of cranial nerves is considered in its initial stage of research, thus, there is a need to summarize the research results achieved to date. Detailed scanning protocols, which assist in mastery of the techniques, are briefly mentioned in the few reference textbooks available in the field. This review article focuses on ultrasound scanning techniques of the 4 accessible cranial nerves: optic, facial, vagus and spinal accessory nerves. The relevant literatures and potential future applications are discussed.

  14. Analisis de Alteraciones EN la Imagen Debidas a Descolimacion de un Telescopio

    NASA Astrophysics Data System (ADS)

    Cobos, F. J.; Galan, M. J.

    1987-05-01

    Podemos considerar, en términos generales, que los espejos de un telescopio tienen una calidad óptica intrínseca, entendiendo por ésta la que se ha obtenido como resultado, fundamentalmente, de la destreza del personal del Taller Optico, que considerará terminadas las superficies ópticas cuando éstas satisfagan los requisitos de diseño y las pruebas de evaluación pertinentes. Debemos esperar que, una vez instalados los espejos en el telescopio, no se altere esta calidad de la óptica por un funcionamiento inadecuado de partes mecánicas del mismo. En los últimos años, en la medida que los problemas de infraestructuratura de nuestros Observatorios se han ido resolviendo, se ha hecho más patente la necesidad de llevar a la instrumentación existente al máximo de su potencial y parte esencial de ésta la conforman los mismos te lescopios. Mejorar la calidad óptica de las imágenes obtenidas con ellos ha hecho que sea prioritario el realizar una investigación más sistemática de sus características. Este trabajo ha tenido como objetivo primordial el usar un programa de diseño óptico, en el caso particular del telescopio UNAM212, con el fin de calcular y obtener gráficamente los diagramas de manchas de imagenes en foco y extrafocales, tanto con la óptica perfectamente alineada como descolimándola (mediante pequenos giros y descentramientos de los espejos). De esta manera, se hizo una evaluación de los efectos que estas alteraciones simuladas producirían en las imágenes focales y extra focales para así poder compararlas con las que realmente se han observado. Asimismo, se ha buscado información bibliográfica, en particular sobre los efectos de giros y descentramientos en las imágenes extrafocales, en lo que se ref iere a la falta de concentricidad de los círculos que forman la "dona" y a la distribución de intensidad luminosa en la misma. De ésta, l futuro un proceso que, haciendo uso de los detectores bidimensionales, nos permita Ilevar a

  15. DYNAMIC NEUROMUSCULAR STABILIZATION & SPORTS REHABILITATION

    PubMed Central

    Kobesova, Alena; Kolar, Pavel

    2013-01-01

    Dynamic neuromuscular (core) stability is necessary for optimal athletic performance and is not achieved purely by adequate strength of abdominals, spinal extensors, gluteals or any other musculature; rather, core stabilization is accomplished through precise coordination of these muscles and intra‐abdominal pressure regulation by the central nervous system. Understanding developmental kinesiology provides a framework to appreciate the regional interdependence and the inter‐linking of the skeleton, joints, musculature during movement and the importance of training both the dynamic and stabilizing function of muscles in the kinetic chain. The Dynamic Neuromuscular Stabilization (DNS) approach provides functional tools to assess and activate the intrinsic spinal stabilizers in order to optimize the movement system for both pre‐habilitation and rehabilitation of athletic injuries and performance. Level of Evidence: 5 PMID:23439921

  16. Neuromuscular fatigue in racquet sports.

    PubMed

    Girard, Olivier; Millet, Grégoire P

    2008-02-01

    This article describes the physiologic and neural mechanisms that cause neuromuscular fatigue in racquet sports: table tennis, tennis, squash, and badminton. In these intermittent and dual activities, performance may be limited as a match progresses because of a reduced central activation, linked to changes in neurotransmitter concentration or in response to afferent sensory feedback. Alternatively, modulation of spinal loop properties may occur because of changes in metabolic or mechanical properties within the muscle. Finally, increased fatigue manifested by mistimed strokes, lower speed, and altered on-court movements may be caused by ionic disturbances and impairments in excitation-contraction coupling properties. These alterations in neuromuscular function contribute to decrease in racquet sports performance observed under fatigue.

  17. [Respiratory treatments in neuromuscular disease].

    PubMed

    Martínez Carrasco, C; Cols Roig, M; Salcedo Posadas, A; Sardon Prado, O; Asensio de la Cruz, O; Torrent Vernetta, A

    2014-10-01

    In a previous article, a review was presented of the respiratory pathophysiology of the patient with neuromuscular disease, as well as their clinical evaluation and the major complications causing pulmonary deterioration. This article presents the respiratory treatments required to preserve lung function in neuromuscular disease as long as possible, as well as in special situations (respiratory infections, spinal curvature surgery, etc.). Special emphasis is made on the use of non-invasive ventilation, which is changing the natural history of many of these diseases. The increase in survival and life expectancy of these children means that they can continue their clinical care in adult units. The transition from pediatric care must be an active, timely and progressive process. It may be slightly stressful for the patient before the adaptation to this new environment, with multidisciplinary care always being maintained.

  18. Neuromuscular fatigue in racquet sports.

    PubMed

    Girard, Olivier; Millet, Grégoire P

    2009-02-01

    This article describes the physiologic and neural mechanisms that cause neuromuscular fatigue in racquet sports: table tennis, tennis, squash, and badminton. In these intermittent and dual activities, performance may be limited as a match progresses because of a reduced central activation, linked to changes in neurotransmitter concentration or in response to afferent sensory feedback. Alternatively, modulation of spinal loop properties may occur because of changes in metabolic or mechanical properties within the muscle. Finally, increased fatigue manifested by mistimed strokes, lower speed, and altered on-court movements may be caused by ionic disturbances and impairments in excitation-contraction coupling properties. These alterations in neuromuscular function contribute to decrease in racquet sports performance observed under fatigue.

  19. Neuromuscular Disease Models and Analysis.

    PubMed

    Burgess, Robert W; Cox, Gregory A; Seburn, Kevin L

    2016-01-01

    Neuromuscular diseases can affect the survival of peripheral neurons, their axons extending to peripheral targets, their synaptic connections onto those targets, or the targets themselves. Examples include motor neuron diseases such as Amyotrophic Lateral Sclerosis, peripheral neuropathies such as Charcot-Marie-Tooth diseases, myasthenias, and muscular dystrophies. Characterizing these phenotypes in mouse models requires an integrated approach, examining both the nerve and muscle histologically, anatomically, and functionally by electrophysiology. Defects observed at these levels can be related back to onset, severity, and progression, as assessed by "Quality of life measures" including tests of gross motor performance such as gait or grip strength. This chapter describes methods for assessing neuromuscular disease models in mice, and how interpretation of these tests can be complicated by the inter-relatedness of the phenotypes. PMID:27150099

  20. [Respiratory treatments in neuromuscular disease].

    PubMed

    Martínez Carrasco, C; Cols Roig, M; Salcedo Posadas, A; Sardon Prado, O; Asensio de la Cruz, O; Torrent Vernetta, A

    2014-10-01

    In a previous article, a review was presented of the respiratory pathophysiology of the patient with neuromuscular disease, as well as their clinical evaluation and the major complications causing pulmonary deterioration. This article presents the respiratory treatments required to preserve lung function in neuromuscular disease as long as possible, as well as in special situations (respiratory infections, spinal curvature surgery, etc.). Special emphasis is made on the use of non-invasive ventilation, which is changing the natural history of many of these diseases. The increase in survival and life expectancy of these children means that they can continue their clinical care in adult units. The transition from pediatric care must be an active, timely and progressive process. It may be slightly stressful for the patient before the adaptation to this new environment, with multidisciplinary care always being maintained. PMID:24890888

  1. Tests of gastric neuromuscular function.

    PubMed

    Parkman, Henry P; Jones, Michael P

    2009-05-01

    Tests of gastric neuromuscular function are used to evaluate patients with symptoms referable to the upper digestive tract. These symptoms can be associated with alterations in the rates of gastric emptying, impaired accommodation, heightened gastric sensation, or alterations in gastric myoelectrical function and contractility. Management of gastric neuromuscular disorders requires an understanding of pathophysiology and treatment options as well as the appropriate use and interpretation of diagnostic tests. These tests include measures of gastric emptying; contractility; electrical activity; regional gastric motility of the fundus, antrum, and pylorus; and tests of sensation and compliance. Tests are also being developed to improve our understanding of the afferent sensory pathways from the stomach to the central nervous system that mediate gastric sensation in health and gastric disorders. This article reviews tests of gastric function and provides a basic description of the tests, the methodologies behind them, descriptions of the physiology that they assess, and their clinical utility. PMID:19293005

  2. Neuromuscular ultrasound in common entrapment neuropathies.

    PubMed

    Cartwright, Michael S; Walker, Francis O

    2013-11-01

    Neuromuscular ultrasound involves the use of high-resolution ultrasound to image the peripheral nervous system of patients with suspected neuromuscular diseases. It complements electrodiagnostic studies well by providing anatomic information regarding nerves, muscles, vessels, tendons, ligaments, bones, and other structures that cannot be obtained with nerve conduction studies and electromyography. Neuromuscular ultrasound has been studied extensively over the past 10 years and has been used most often in the assessment of entrapment neuropathies. This review focuses on the use of neuromuscular ultrasound in 4 of the most common entrapment neuropathies: carpal tunnel syndrome, ulnar neuropathy at the elbow and wrist, and fibular neuropathy at the knee.

  3. Common complications of pediatric neuromuscular disorders.

    PubMed

    Skalsky, Andrew J; Dalal, Pritha B

    2015-02-01

    Children with pediatric neuromuscular disorders experience common complications, primarily due to immobility and weakness. Musculoskeletal complications include hip dysplasia with associated hip subluxation or dislocation, neuromuscular scoliosis, and osteoporosis and resulting fractures. Constipation, gastroesophageal reflux, and obesity and malnutrition are commonly experienced gastrointestinal complications. Disordered sleep also is frequently observed, which affects both patients and caregivers. PMID:25479776

  4. Neuromuscular Control and Coordination during Cycling

    ERIC Educational Resources Information Center

    Li, Li

    2004-01-01

    The neuromuscular control aspect of cycling has been investigated through the effects of modifying posture and cadence. These studies show that changing posture has a more profound influence on neuromuscular coordination than does changing slope. Most of the changes with standing posture occur late in the downstroke: increased ankle and knee joint…

  5. Neuromuscular Highlights-AAN 2005.

    PubMed

    Cheema, Zahid; Saperstein, David; Jackson, Carolyn; Newman, Daniel

    2006-06-01

    Summary of Neuromuscular Presentations at the 57 Annual AAN 2005 meeting in Miami Florida on topics of Facioscapulohumeral muscular dystrophy (FSHD), Duchenne muscular dystrophy (DMD), Diabetic Neuropathy, Charco Marie Tooth disease (CMT), Comparison of injected steroids versus Surgery for carpal tunnel syndrome, Rituximab in Anti-MAG associated polyneuropathy, Cannabis based medicine (CBM) in the treatment of neuropathic pain, utility of skin biopsy with intraepidermal nerve fiber density (IENFD) in sensory complaints, comparing sympathetic skin responses (SSRs) and skin biopsy in diagnosing small fiber sensory neuropathy, Chronic inflammatory demyelinating polyneuropathy (CIDP) clinical and electrophysiologic predictors, affect of limb warming in mild ulnar nerve conduction study (NCS) abnormalities, Tamoxifen affect in ALS, open label study of 3,4 DAP, Pyridostigmine and Ephedrine in fast channel syndrome, Mexilitine as an antimyotonia treatment in myotonic dystrophy (DM1), frontal lobe impairment evaluation in DM1 and DM2 patients and phenotype-genotype correlation in patients with dysferlinopathy. PMID:19078809

  6. Novel drug development for neuromuscular blockade

    PubMed Central

    Prabhakar, Amit; Kaye, Alan D; Wyche, Melville Q; Salinas, Orlando J; Mancuso, Kenneth; Urman, Richard D

    2016-01-01

    Pharmacological advances in anesthesia in recent decades have resulted in safer practice and better outcomes. These advances include improvement in anesthesia drugs with regard to efficacy and safety profiles. Although neuromuscular blockers were first introduced over a half century ago, few new neuromuscular blockers and reversal agents have come to market and even fewer have remained as common clinically employed medications. In recent years, newer agents have been studied and are presented in this review. With regard to nondepolarizer neuromuscular blocker agents, the enantiomers Gantacurium and CW002, which are olefinic isoquinolinium diester fumarates, have shown potential for clinical application. Advantages include ultra rapid reversal of neuromuscular blockade via cysteine adduction and minimal systemic hemodynamic effects with administration. PMID:27625489

  7. School Intervention for the Neuromuscularly Handicapped Child.

    ERIC Educational Resources Information Center

    Hall, Colin D.; Porter, Patricia

    1983-01-01

    Difficulties encountered in school by 35 neuromuscularly handicapped children, (5 to 18 years old) were assessed, and methods of alleviating problems were developed. (SEW) Journal Availability: The C. V. Mosby Company, 11830 Westline Industrial Drive, St. Louis, MO 63141.

  8. Novel drug development for neuromuscular blockade

    PubMed Central

    Prabhakar, Amit; Kaye, Alan D; Wyche, Melville Q; Salinas, Orlando J; Mancuso, Kenneth; Urman, Richard D

    2016-01-01

    Pharmacological advances in anesthesia in recent decades have resulted in safer practice and better outcomes. These advances include improvement in anesthesia drugs with regard to efficacy and safety profiles. Although neuromuscular blockers were first introduced over a half century ago, few new neuromuscular blockers and reversal agents have come to market and even fewer have remained as common clinically employed medications. In recent years, newer agents have been studied and are presented in this review. With regard to nondepolarizer neuromuscular blocker agents, the enantiomers Gantacurium and CW002, which are olefinic isoquinolinium diester fumarates, have shown potential for clinical application. Advantages include ultra rapid reversal of neuromuscular blockade via cysteine adduction and minimal systemic hemodynamic effects with administration.

  9. Novel drug development for neuromuscular blockade.

    PubMed

    Prabhakar, Amit; Kaye, Alan D; Wyche, Melville Q; Salinas, Orlando J; Mancuso, Kenneth; Urman, Richard D

    2016-01-01

    Pharmacological advances in anesthesia in recent decades have resulted in safer practice and better outcomes. These advances include improvement in anesthesia drugs with regard to efficacy and safety profiles. Although neuromuscular blockers were first introduced over a half century ago, few new neuromuscular blockers and reversal agents have come to market and even fewer have remained as common clinically employed medications. In recent years, newer agents have been studied and are presented in this review. With regard to nondepolarizer neuromuscular blocker agents, the enantiomers Gantacurium and CW002, which are olefinic isoquinolinium diester fumarates, have shown potential for clinical application. Advantages include ultra rapid reversal of neuromuscular blockade via cysteine adduction and minimal systemic hemodynamic effects with administration. PMID:27625489

  10. Sugammadex: A Review of Neuromuscular Blockade Reversal.

    PubMed

    Keating, Gillian M

    2016-07-01

    Sugammadex (Bridion(®)) is a modified γ-cyclodextrin that reverses the effect of the steroidal nondepolarizing neuromuscular blocking agents rocuronium and vecuronium. Intravenous sugammadex resulted in rapid, predictable recovery from moderate and deep neuromuscular blockade in patients undergoing surgery who received rocuronium or vecuronium. Recovery from moderate neuromuscular blockade was significantly faster with sugammadex 2 mg/kg than with neostigmine, and recovery from deep neuromuscular blockade was significantly faster with sugammadex 4 mg/kg than with neostigmine or spontaneous recovery. In addition, recovery from neuromuscular blockade was significantly faster when sugammadex 16 mg/kg was administered 3 min after rocuronium than when patients spontaneously recovered from succinylcholine. Sugammadex also demonstrated efficacy in various special patient populations, including patients with pulmonary disease, cardiac disease, hepatic dysfunction or myasthenia gravis and morbidly obese patients. Intravenous sugammadex was generally well tolerated. In conclusion, sugammadex is an important option for the rapid reversal of rocuronium- or vecuronium-induced neuromuscular blockade. PMID:27324403

  11. Neuromuscular blockade in the elderly patient

    PubMed Central

    Lee, Luis A; Athanassoglou, Vassilis; Pandit, Jaideep J

    2016-01-01

    Neuromuscular blockade is a desirable or even essential component of general anesthesia for major surgical operations. As the population continues to age, and more operations are conducted in the elderly, due consideration must be given to neuromuscular blockade in these patients to avoid possible complications. This review considers the pharmacokinetics and pharmacodynamics of neuromuscular blockade that may be altered in the elderly. Compartment distribution, metabolism, and excretion of drugs may vary due to age-related changes in physiology, altering the duration of action with a need for reduced dosage (eg, aminosteroids). Other drugs (atracurium, cisatracurium) have more reliable duration of action and should perhaps be considered for use in the elderly. The range of interpatient variability that neuromuscular blocking drugs may exhibit is then considered and drugs with a narrower range, such as cisatracurium, may produce more predictable, and inherently safer, outcomes. Ultimately, appropriate neuromuscular monitoring should be used to guide the administration of muscle relaxants so that the risk of residual neuromuscular blockade postoperatively can be minimized. The reliability of various monitoring is considered. This paper concludes with a review of the various reversal agents, namely, anticholinesterase drugs and sugammadex, and the alterations in dosing of these that should be considered for the elderly patient. PMID:27382330

  12. Neuromuscular Adaptations to Reduced Use

    NASA Technical Reports Server (NTRS)

    Ploutz-Snyder, Lori

    2009-01-01

    This viewgraph presentation reviews the studies done to reduce neuromuscular strength loss during unilateral lower limb suspension (ULLS). Since there are animals that undergo fairly long periods of muscular disuse without any or minimal muscular atrophy, there is an answer to that might be applicable to human in situations that require no muscular use to diminish the effects of muscular atrophy. Three sets of ULLS studies were reviewed indicated that muscle strength decreased more than the muscle mass. The study reviewed exercise countermeasures to combat the atrophy, including: ischemia maintained during Compound muscle action potential (CMAP), ischemia and low load exercise, Japanese kaatsu, and the potential for rehabilitation or situations where heavy loading is undesirable. Two forms of countermeasures to unloading have been successful, (1) high-load resistance training has maintained muscle mass and strength, and low load resistance training with blood flow restriction (LL(sub BFR)). The LL(sub BFR) has been shown to increase muscle mass and strength. There has been significant interest in Tourniquet training. An increase in Growth Hormone(GH) has been noted for LL(sub BFR) exercise. An experimental study with 16 subjects 8 of whom performed ULLS, and 8 of whom performed ULLS and LL(sub BFR) exercise three times per week during the ULLS. Charts show the results of the two groups, showing that performing LL(sub BFR) exercise during 30 days of ULLS can maintain muscle size and strength and even improve muscular endurance.

  13. Splicing therapy for neuromuscular disease☆

    PubMed Central

    Douglas, Andrew G.L.; Wood, Matthew J.A.

    2013-01-01

    Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA) are two of the most common inherited neuromuscular diseases in humans. Both conditions are fatal and no clinically available treatments are able to significantly alter disease course in either case. However, by manipulation of pre-mRNA splicing using antisense oligonucleotides, defective transcripts from the DMD gene and from the SMN2 gene in SMA can be modified to once again produce protein and restore function. A large number of in vitro and in vivo studies have validated the applicability of this approach and an increasing number of preliminary clinical trials have either been completed or are under way. Several different oligonucleotide chemistries can be used for this purpose and various strategies are being developed to facilitate increased delivery efficiency and prolonged therapeutic effect. As these novel therapeutic compounds start to enter the clinical arena, attention must also be drawn to the question of how best to facilitate the clinical development of such personalised genetic therapies and how best to implement their provision. PMID:23631896

  14. Flightless Flies: Drosophila models of neuromuscular disease

    PubMed Central

    Lloyd, Thomas E.; Taylor, J. Paul

    2010-01-01

    The fruit fly, Drosophila melanogaster, has a long and rich history as an important model organism for biologists. In particular, study of the fruit fly has been essential to much of our fundamental understanding of the development and function of the nervous system. In recent years, studies using fruit flies have provided important insights into the pathogenesis of neurodegenerative and neuromuscular diseases. Fly models of spinal muscular atrophy, spinobulbar muscular atrophy, myotonic dystrophy, dystrophinopathies and other inherited neuromuscular diseases recapitulate many of the key pathologic features of the human disease. The ability to perform genetic screens holds promise for uncovering the molecular mechanisms of disease, and indeed, for identifying novel therapeutic targets. This review will summarize recent progress in developing fly models of neuromuscular diseases and will emphasize the contribution that Drosophila has made to our understanding of these diseases. PMID:20329357

  15. Scoliosis and the impact in neuromuscular disease.

    PubMed

    Mayer, Oscar Henry

    2015-01-01

    Scoliosis can alter respiratory mechanics by changing the orientation of the muscles and joints of the respiratory system and in severe forms can put a patient at risk of severe respiratory morbidity or respiratory failure. However, perhaps the most important factor in determining the pulmonary morbidity in scoliosis is the balance between the "load" or altered respiratory mechanics and the "pump" or the respiratory muscle strength. Therefore, scoliosis in patients with neuromuscular disease will both lead to increased "load" and a weakened "pump", an exceptionally unfortunate combination. While progressive neuromuscular disease by its nature does not respond favorably to attempts to improve respiratory muscle strength, the natural approach of early proactive management of the "load" and in the case of scoliosis a variety of different strategies have been tried with variable short term and long term results. Figuring this out requires both an understanding of the underlying pathophysiology of a particular neuromuscular condition and the available options for and timing of surgical intervention.

  16. Neuromuscular disorders and sleep in critically ill patients.

    PubMed

    Irfan, Muna; Selim, Bernardo; Rabinstein, Alejandro A; St Louis, Erik K

    2015-07-01

    Sleep-disordered breathing (SDB) is a frequent presenting manifestation of neuromuscular disorders and can lead to significant morbidity and mortality. If not recognized and addressed early in the clinical course, SDB can lead to clinical deterioration with respiratory failure. The pathophysiologic basis of SDB in neuromuscular disorders, clinical features encountered in specific neuromuscular diseases, and diagnostic and management strategies for SDB in neuromuscular patients in the critical care setting are reviewed. Noninvasive positive pressure ventilation has been a crucial advance in critical care management, improving sleep quality and often preventing or delaying mechanical ventilation and improving survival in neuromuscular patients.

  17. Neuromuscular Disorders and Sleep in Critically Ill Patients

    PubMed Central

    Irfan, Muna; Selim, Bernardo; Rabinstein, Alejandro A.

    2016-01-01

    Synopsis Sleep-disordered breathing (SDB) is a frequent presenting manifestation of neuromuscular disorders and can lead to significant morbidity and mortality. If not promptly recognized and addressed early in the clinical course, SDB can lead to clinical deterioration with respiratory failure. In this article, we review the pathophysiologic basis of SDB in neuromuscular disorders, clinical features encountered in specific neuromuscular diseases, and diagnostic and management strategies for SDB in neuromuscular patients in the critical care setting. Non-invasive positive pressure ventilation (NIPV) has been a crucial advance in critical care management, improving sleep quality and often preventing or delaying mechanical ventilation and improving survival in neuromuscular patients. PMID:26118919

  18. Electrodiagnosis of disorders of neuromuscular transmission.

    PubMed

    Howard, James F

    2013-02-01

    This article reviews the use of electrodiagnostic testing in disorders of neuromuscular transmission and discusses the differences between various presynaptic and postsynaptic disorders. Attention is paid to quality control issues that influence the sensitivity of repetitive nerve stimulation and single fiber electromyography. Electrodiagnostic testing, when used as an extension of the clinician's history and physical examination, will provide appropriate direction in establishing the diagnosis.

  19. Dynamic Flexibility and Proprioceptive Neuromuscular Facilitation.

    ERIC Educational Resources Information Center

    Hardy, Lew; Jones, David

    1986-01-01

    Two experiments are described which investigated whether results obtained in studies of static flexibility tranfer to dynamic flexibility. In both experiments, subjects were assigned to a group receiving proprioceptive neuromuscular facilitation training, ballistic stretching technique training or a control group. Results are presented and…

  20. Neuromuscular blockers—a means of palliation?

    PubMed Central

    Hawryluck, L

    2002-01-01

    As we die, our respiratory pattern is altered and we seem to gasp and struggle for each breath. Such gasping is commonly seen as a clear sign of dyspnoea and suffering by families and loved ones, however, it is unclear whether it is perceived at all by the dying person. Narcotics and sedatives do not seem to affect these gasping respirations. In this issue of the Journal of Medical Ethics, we are asked to consider whether the last gasp of a dying patient could be or, perhaps, even should be avoided by administering neuromuscular blockers to palliate dying patients. For many reasons, such as our current failure to alleviate pain and distress, stories of inadequate analgesia and sedation in critically ill paralysed patients and the inability to know the intent—whether to palliate or to euthanise—it would seem that administering neuromuscular blockers should not be ethically permissible. PMID:12042402

  1. Neuromuscular choristoma of the internal auditory meatus.

    PubMed

    Nikolaou, Georgios; Röösli, Christof; Huber, Alex; Probst, Rudolf

    2012-01-01

    Choristomas of the internal auditory meatus are exceedingly rare tumors. In most cases, neuromuscular choristomas have initially been misdiagnosed as vestibular schwannomas (VS). No known characteristics in the clinical presentation or in imaging exist distinguishing these tumors from VS, which are the most common tumors at this location [Smith et al.: AJNR Am J Neuroradiol 1997;18:327-329]. We present a case of a neuromuscular choristoma of the 8th cranial nerve that was operated because of growth demonstrated on two MRI scans 3 months apart. We were convinced that this young patient would require treatment sometime in the future, and we believed that an operation at that time had higher chances to preserve the anatomical structures. Histomorphological examination of the tumor revealed a nodular lesion with fascicular and nodular assembled smooth muscle cells, connective tissue and nerve fibers.

  2. Targeting RNA to treat neuromuscular disease.

    PubMed

    Muntoni, Francesco; Wood, Matthew J A

    2011-08-01

    The development of effective therapies for neuromuscular disorders such as Duchenne muscular dystrophy (DMD) is hampered by considerable challenges: skeletal muscle is the most abundant tissue in the body, and many neuromuscular disorders are multisystemic conditions. However, despite these barriers there has recently been substantial progress in the search for novel treatments. In particular, the use of antisense oligonucleotides, which are designed to target RNA and modulate pre-mRNA splicing to restore functional protein isoforms or directly inhibit the toxic effects of pathogenic RNAs, offers great promise and these approaches are now being tested in the clinic. Here, we review recent advances in the development of such antisense oligonucleotides and other promising novel approaches, including the induction of readthrough nonsense mutations.

  3. Neuromuscular Electrical Stimulation for Skeletal Muscle Function

    PubMed Central

    Doucet, Barbara M.; Lam, Amy; Griffin, Lisa

    2012-01-01

    Lack of neural innervation due to neurological damage renders muscle unable to produce force. Use of electrical stimulation is a medium in which investigators have tried to find a way to restore movement and the ability to perform activities of daily living. Different methods of applying electrical current to modify neuromuscular activity are electrical stimulation (ES), neuromuscular electrical stimulation (NMES), transcutaneous electrical nerve stimulation (TENS), and functional electrical stimulation (FES). This review covers the aspects of electrical stimulation used for rehabilitation and functional purposes. Discussed are the various parameters of electrical stimulation, including frequency, pulse width/duration, duty cycle, intensity/amplitude, ramp time, pulse pattern, program duration, program frequency, and muscle group activated, and how they affect fatigue in the stimulated muscle. PMID:22737049

  4. Neuromuscular monitoring: old issues, new controversies.

    PubMed

    Kopman, Aaron F

    2009-03-01

    "Expert" editorial opinion suggests that objective or quantitative neuromuscular monitors should be used whenever nondepolarizing blocking agents are administered. It is clear that this advice has by and large fallen on deaf ears. A sizeable number of clinicians here (North America) and abroad (Europe) fail to use even conventional peripheral nerve stimulators routinely. This chapter will explore potential reasons for and consequences of this disconnect between academia and "the real world." Along the way, we will examine such questions as how do we define and measure adequate recovery from nondepolarizing block. What are the limitations of clinical tests of recovery such as the "head-lift test?" What is the incidence of undetected postoperative residual curarization (PORC)? Does neuromuscular monitoring reduce the frequency of PORC? How will the availability of sugammadex alter the above discussion? PMID:19272534

  5. Diurnal hypercapnia in patients with neuromuscular disease.

    PubMed

    Panitch, Howard B

    2010-03-01

    Subjects with progressive neuromuscular diseases undergo a typical sequence of respiratory compromise, leading from normal unassisted gas exchange to nocturnal hypoventilation with normal daytime gas exchange, and eventually to respiratory failure requiring continuous ventilatory support. Several different abnormalities in respiratory pump function have been described to explain the development of respiratory failure in subjects with neuromuscular weakness. Early in the progression of respiratory failure, the use of nocturnal assisted ventilation can reverse both night- and day-time hypercapnia. Eventually, however, diurnal hypercapnia will persist despite correction of nocturnal hypoventilation. The likely beneficial effects of mechanical ventilatory support include resting fatigue-prone respiratory muscles and resetting of the central chemoreceptors to PaCO(2). Recent experience shows that select patients who require daytime ventilation can be supported with non-invasive ventilation continuously to correct gas exchange abnormalities while avoiding detrimental aspects of tracheostomy placement.

  6. Neuromuscular rehabilitation and electrodiagnosis. 4. Specialized neuropathy.

    PubMed

    Agre, J C; Sliwa, J A

    2000-03-01

    This self-directed learning module briefly highlights the differential diagnosis for acute weakness in patients with acute respiratory failure requiring prolonged mechanical ventilation. It is part of the chapter on neuromuscular rehabilitation and electrodiagnosis in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. This article includes a discussion on the role of exercise in the treatment of patients with the late effects of poliomyelitis or with acute inflammatory demyelinating polyradiculoneuropathy.

  7. Neuromuscular control of prey capture in frogs.

    PubMed Central

    Nishikawa, K C

    1999-01-01

    While retaining a feeding apparatus that is surprisingly conservative morphologically, frogs as a group exhibit great variability in the biomechanics of tongue protraction during prey capture, which in turn is related to differences in neuromuscular control. In this paper, I address the following three questions. (1) How do frog tongues differ biomechanically? (2) What anatomical and physiological differences are responsible? (3) How is biomechanics related to mechanisms of neuromuscular control? Frog species use three non-exclusive mechanisms to protract their tongues during feeding: (i) mechanical pulling, in which the tongue shortens as its muscles contract during protraction; (ii) inertial elongation, in which the tongue lengthens under inertial and muscular loading; and (iii) hydrostatic elongation, in which the tongue lengthens under constraints imposed by the constant volume of a muscular hydrostat. Major differences among these functional types include (i) the amount and orientation of collagen fibres associated with the tongue muscles and the mechanical properties that this connective tissue confers to the tongue as a whole; and (ii) the transfer of intertia from the opening jaws to the tongue, which probably involves a catch mechanism that increases the acceleration achieved during mouth opening. The mechanisms of tongue protraction differ in the types of neural mechanisms that are used to control tongue movements, particularly in the relative importance of feed-forward versus feedback control, in requirements for precise interjoint coordination, in the size and number of motor units, and in the afferent pathways that are involved in coordinating tongue and jaw movements. Evolution of biomechanics and neuromuscular control of frog tongues provides an example in which neuromuscular control is finely tuned to the biomechanical constraints and opportunities provided by differences in morphological design among species. PMID:10382226

  8. Neuromuscular Diseases Associated with HIV-1 Infection

    PubMed Central

    Robinson-Papp, Jessica; Simpson, David M.

    2010-01-01

    Neuromuscular disorders are common in HIV, occurring at all stages of disease and affecting all parts of the peripheral nervous system. These disorders have diverse etiologies including HIV itself, immune suppression and dysregulation, co-morbid illnesses and infections, and side effects of medications. In this article, we review the following HIV-associated conditions: distal symmetric polyneuropathy, inflammatory demyelinating polyneuropathy, mononeuropathy, mononeuropathy multiplex, autonomic neuropathy, progressive polyradiculopathy due to cytomegalovirus, herpes zoster, myopathy and other rarer disorders. PMID:19771594

  9. Neuromuscular adaptation to actual and simulated weightlessness

    NASA Technical Reports Server (NTRS)

    Edgerton, V. R.; Roy, R. R.

    1994-01-01

    The chronic "unloading" of the neuromuscular system during spaceflight has detrimental functional and morphological effects. Changes in the metabolic and mechanical properties of the musculature can be attributed largely to the loss of muscle protein and the alteration in the relative proportion of the proteins in skeletal muscle, particularly in the muscles that have an antigravity function under normal loading conditions. These adaptations could result in decrements in the performance of routine or specialized motor tasks, both of which may be critical for survival in an altered gravitational field, i.e., during spaceflight and during return to 1 G. For example, the loss in extensor muscle mass requires a higher percentage of recruitment of the motor pools for any specific motor task. Thus, a faster rate of fatigue will occur in the activated muscles. These consequences emphasize the importance of developing techniques for minimizing muscle loss during spaceflight, at least in preparation for the return to 1 G after spaceflight. New insights into the complexity and the interactive elements that contribute to the neuromuscular adaptations to space have been gained from studies of the role of exercise and/or growth factors as countermeasures of atrophy. The present chapter illustrates the inevitable interactive effects of neural and muscular systems in adapting to space. It also describes the considerable progress that has been made toward the goal of minimizing the functional impact of the stimuli that induce the neuromuscular adaptations to space.

  10. THE ANALYSIS OF NEUROMUSCULAR MECHANISMS IN CHITON.

    PubMed

    Crozier, W J

    1920-07-20

    1. The degree of curvature of the body and of the girdle of a Chiton is determined by the activity of antagonistic muscle groups. At a certain, early stage in the strychninization of a Chiton the reciprocal inhibition involved in the natural use of these muscle groups is reversed, such that extensor muscles, rather than, as normally, flexor muscles, contract as the result of stimulation. This condition involves a reversal, under strychnine, of the normally positive stereotropism of the foot, and of the usual response of the mollusk to an increased illumination of its ventral surface. Strychnine reversal of this character is not a matter of the relative strength of the opposed muscle groups, for the flexor muscles are the more powerful and are the ones always shortened in tetanic contraction. 2. Nicotine, in contrast to strychnine, primarily induces contraction of flexor muscles. Its effects, moreover, are in a degree selective, being notably exerted on "cerebral" nervous structures. Curare is devoid of characteristic action on the neuromuscular responses of Chiton. 3. The chemical organization of the neuromuscular organs of Chiton, as far as revealed by these tests, corresponds to a more simple condition than is inferred for gastropods. In particular, the behavior with respect to curare resembles more that of the neuromuscular apparatus of flatworms.

  11. Neuromuscular Disease in the Neurointensive Care Unit.

    PubMed

    Crespo, Veronica; James, Michael L Luke

    2016-09-01

    Neuromuscular diseases are syndromic disorders that affect nerve, muscle, and/or neuromuscular junction. Knowledge about the management of these diseases is required for anesthesiologists, because these may frequently be encountered in the intensive care unit, operating room, and other settings. The challenges and advances in management for some of the neuromuscular diseases most commonly encountered in the operating room and neurointensive care unit are reviewed. PMID:27521200

  12. Acute neuromuscular weakness associated with dengue infection

    PubMed Central

    Hira, Harmanjit Singh; Kaur, Amandeep; Shukla, Anuj

    2012-01-01

    Background: Dengue infections may present with neurological complications. Whether these are due to neuromuscular disease or electrolyte imbalance is unclear. Materials and Methods: Eighty-eight patients of dengue fever required hospitalization during epidemic in year 2010. Twelve of them presented with acute neuromuscular weakness. We enrolled them for study. Diagnosis of dengue infection based on clinical profile of patients, positive serum IgM ELISA, NS1 antigen, and sero-typing. Complete hemogram, kidney and liver functions, serum electrolytes, and creatine phosphokinase (CPK) were tested. In addition, two patients underwent nerve conduction velocity (NCV) test and electromyography. Results: Twelve patients were included in the present study. Their age was between 18 and 34 years. Fever, myalgia, and motor weakness of limbs were most common presenting symptoms. Motor weakness developed on 2nd to 4th day of illness in 11 of 12 patients. In one patient, it developed on 10th day of illness. Ten of 12 showed hypokalemia. One was of Guillain-Barré syndrome and other suffered from myositis; they underwent NCV and electromyography. Serum CPK and SGOT raised in 8 out of 12 patients. CPK of patient of myositis was 5098 IU. All of 12 patients had thrombocytopenia. WBC was in normal range. Dengue virus was isolated in three patients, and it was of serotype 1. CSF was normal in all. Within 24 hours, those with hypokalemia recovered by potassium correction. Conclusions: It was concluded that the dengue virus infection led to acute neuromuscular weakness because of hypokalemia, myositis, and Guillain-Barré syndrome. It was suggested to look for presence of hypokalemia in such patients. PMID:22346188

  13. Neuromuscular Functions on Experimental Acute Methanol Intoxication

    PubMed Central

    Moral, Ali Reşat; Çankayalı, İlkin; Sergin, Demet; Boyacılar, Özden

    2015-01-01

    Objective The incidence of accidental or suicidal ingestion of methyl alcohol is high and methyl alcohol intoxication has high mortality. Methyl alcohol intoxication causes severe neurological sequelae and appears to be a significant problem. Methyl alcohol causes acute metabolic acidosis, optic neuropathy leading to permanent blindness, respiratory failure, circulatory failure and death. It is metabolised in the liver, and its metabolite formic acid has direct toxic effects, causing oxidative stress, mitochondrial damage and increased lipid peroxidation associated with the mechanism of neurotoxicity. Methanol is known to cause acute toxicity of the central nervous system; however, the effects on peripheral neuromuscular transmission are unknown. In our study, we aimed to investigate the electrophysiological effects of experimentally induced acute methanol intoxication on neuromuscular transmission in the early period (first 24 h). Methods After approval by the Animal Experiment Ethics Committee of Ege University, the study was carried out on 10 Wistar rats, each weighing about 200 g. During electrophysiological recordings and orogastric tube insertion, the rats were anaesthetised using intra-peritoneal (IP) injection of ketamine 100 mg kg−1 and IP injection of xylazine 10 mg kg−1. The rats were given 3 g kg−1 methyl alcohol by the orogastric tube. Electrophysiological measurements from the gastrocnemius muscle were compared with baseline. Results Latency measurements before and 24 h after methanol injection were 0.81±0.11 ms and 0.76±0.12 ms, respectively. CMAP amplitude measurements before and 24 h after methanol injection were 9.85±0.98 mV and 9.99±0.40 mV, respectively. CMAP duration measurements before and 24 h after methanol injection were 9.86±0.03 ms and 9.86±0.045 ms, respectively. Conclusion It was concluded that experimental methanol intoxication in the acute phase (first 24 h) did not affect neuromuscular function. PMID:27366524

  14. IPPB-assisted coughing in neuromuscular disorders.

    PubMed

    Dohna-Schwake, Christian; Ragette, Regine; Teschler, Helmut; Voit, Thomas; Mellies, Uwe

    2006-06-01

    In neuromuscular disorders, reduced peak cough flows (PCFs) are considered to increase the risk of respiratory complications such as pneumonia or chronic atelectasis. Different methods were described to improve PCF. However, these studies were primarily carried out in adults, and there is limited information regarding the use and efficacy of these methods in children with respiratory muscle weakness. The aim of this study was to investigate whether hyperinsufflation with an intermittent positive-pressure breathing (IPPB) device is effective in cough augmentation in pediatric patients. Spirometry (forced inspiratory vital capacity, FIVC; forced expiratory volume in 1 sec, FEV1), respiratory muscle pressures (peak inspiratory pressure, PIP; peak expiratory pressure, PEP), and PCF were measured in 29 schoolchildren with various neuromuscular disorders. IPPB-assisted hyperinsufflation was taught individually to increase lung volumes (maximum insufflation capacity, MIC) above FIVC. The impact of hyperinsufflation on peak cough flow was documented. In 28/29 patients, IPPB-assisted hyperinsufflation enhanced FIVC from 0.68 +/- 0.40 l to an MIC of 1.05 +/- 0.47 l (P < 0.001). Unassisted PCF was 119.0 +/- 57.7 l/min, and increased to 194.5 +/- 74.9 l/min (P < 0.001) in 27/29 patients. This effect was similar in young patients (ages 6-10 years) and older patients (aged >10 years). Augmentation of lung volumes from FIVC to MIC correlated with an increase of PCF (R = 0.42, P < 0.05). IPPB-assisted hyperinsufflation improves PCF in pediatric neuromuscular disorders. The results suggest that this technique can be used to improve clearance of airway secretions and therefore reduce respiratory morbidity in children with NMD.

  15. Neuromuscular Development and Regulation of Myosin Expression

    NASA Technical Reports Server (NTRS)

    Bodine, Sue

    1997-01-01

    The proposed experiments were designed to determine whether the absence of gravity during embryogenesis influences the postnatal development of the neuromuscular system. Further, we examined the effects of reduced gravity on hindlimb muscles of the pregnant rats. Microgravity may have short and long-term effects on the development of muscle fiber type differentiation and force producing capabilities. Microgravity will reduce muscle fiber size and cause a shift in myosin heavy chain expression from slow to fast in hindlimb muscles of the adult pregnant rats.

  16. Neuromuscular Blockade and Reversal Agents: A Primer for Postanesthesia Nurses.

    ERIC Educational Resources Information Center

    Pesci, Barbara R.

    1986-01-01

    Presents a comprehensive review of neuromuscular blocking agents, reversal agents used in anesthesia, and factors affecting reversal. It is aimed at nurses who provide care to patients recovering from anesthesia. It discusses the neuromuscular transmission system, depolarizing muscle relaxants, nondepolarizing blocking agents, and criteria for…

  17. Neuromuscular Characteristics of Endurance--And Power-Trained Athletes

    ERIC Educational Resources Information Center

    Koceja, David M.; Davison, Edwin; Robertson, Christopher T.

    2004-01-01

    In response to chronic physical training, the human neuromuscular system undergoes significant and specific adaptations. More importantly, these influences are the result of the type and quantity of physical activity. One of the simplest neuromuscular mechanisms is the spinal stretch reflex. The reflex system was previously viewed as inflexible,…

  18. Motoneuron and sensory neuron plasticity to varying neuromuscular activity levels

    NASA Technical Reports Server (NTRS)

    Ishihara, Akihiko; Roy, Roland R.; Ohira, Yoshinobu; Edgerton, V. Reggie

    2002-01-01

    The size and phenotypic properties of the neural and muscular elements of the neuromuscular unit are matched under normal conditions. When subjected to chronic decreases or increases in neuromuscular activity, however, the adaptations in these properties are much more limited in the neural compared with the muscular elements.

  19. 21 CFR 882.5810 - External functional neuromuscular stimulator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External functional neuromuscular stimulator. 882.5810 Section 882.5810 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... External functional neuromuscular stimulator. (a) Identification. An external functional...

  20. 21 CFR 882.5810 - External functional neuromuscular stimulator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false External functional neuromuscular stimulator. 882.5810 Section 882.5810 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... External functional neuromuscular stimulator. (a) Identification. An external functional...

  1. Recent achievements in restorative neurology: Progressive neuromuscular diseases

    SciTech Connect

    Dimitrijevic, M.R.; Kakulas, B.A.; Vrbova, G.

    1986-01-01

    This book contains 27 chapters. Some of the chapter titles are: Computed Tomography of Muscles in Neuromuscular Disease; Mapping the Genes for Muscular Dystrophy; Trophic Factors and Motor Neuron Development; Size of Motor Units and Firing Rate in Muscular Dystrophy; Restorative Possibilities in Relation to the Pathology of Progressive Neuromuscular Disease; and An Approach to the Pathogenesis of some Congenital Myopathies.

  2. Neuromuscular Dysfunction in Experimental Sepsis and Glutamine

    PubMed Central

    Çankayalı, İlkin; Boyacılar, Özden; Demirağ, Kubilay; Uyar, Mehmet; Moral, Ali Reşat

    2016-01-01

    Background: Electrophysiological studies show that critical illness polyneuromyopathy appears in the early stage of sepsis before the manifestation of clinical findings. The metabolic response observed during sepsis causes glutamine to become a relative essential amino acid. Aims: We aimed to assess the changes in neuromuscular transmission in the early stage of sepsis after glutamine supplementation. Study Design: Animal experimentation. Methods: Twenty male Sprague-Dawley rats were randomized into two groups. Rats in both groups were given normal feeding for one week. In the study group, 1 g/kg/day glutamine was added to normal feeding by feeding tube for one week. Cecal ligation and perforation (CLP) surgery was performed at the end of one week. Before and 24 hours after CLP, compound muscle action potentials were recorded from the gastrocnemius muscle. Results: Latency measurements before and 24 hours after CLP were 0.68±0.05 ms and 0.80±0.09 ms in the control group and 0.69±0.07 ms and 0.73±0.07 ms in the study group (p<0.05). Conclusion: Since enteral glutamine prevented compound muscle action potentials (CMAP) latency prolongation in the early phase of sepsis, it was concluded that enteral glutamine replacement might be promising in the prevention of neuromuscular dysfunction in sepsis; however, further studies are required. PMID:27308070

  3. Neuromuscular imaging in inherited muscle diseases

    PubMed Central

    Kley, Rudolf A.; Fischer, Dirk

    2010-01-01

    Driven by increasing numbers of newly identified genetic defects and new insights into the field of inherited muscle diseases, neuromuscular imaging in general and magnetic resonance imaging (MRI) in particular are increasingly being used to characterise the severity and pattern of muscle involvement. Although muscle biopsy is still the gold standard for the establishment of the definitive diagnosis, muscular imaging is an important diagnostic tool for the detection and quantification of dystrophic changes during the clinical workup of patients with hereditary muscle diseases. MRI is frequently used to describe muscle involvement patterns, which aids in narrowing of the differential diagnosis and distinguishing between dystrophic and non-dystrophic diseases. Recent work has demonstrated the usefulness of muscle imaging for the detection of specific congenital myopathies, mainly for the identification of the underlying genetic defect in core and centronuclear myopathies. Muscle imaging demonstrates characteristic patterns, which can be helpful for the differentiation of individual limb girdle muscular dystrophies. The aim of this review is to give a comprehensive overview of current methods and applications as well as future perspectives in the field of neuromuscular imaging in inherited muscle diseases. We also provide diagnostic algorithms that might guide us through the differential diagnosis in hereditary myopathies. PMID:20422195

  4. Neuromuscular disruption with ultrashort electrical pulses

    NASA Astrophysics Data System (ADS)

    Pakhomov, Andrei; Kolb, Juergen F.; Joshi, Ravindra P.; Schoenbach, Karl H.; Dayton, Thomas; Comeaux, James; Ashmore, John; Beason, Charles

    2006-05-01

    Experimental studies on single cells have shown that application of pulsed voltages, with submicrosecond pulse duration and an electric field on the order of 10 kV/cm, causes sudden alterations in the intracellular free calcium concentration, followed by immobilization of the cell. In order to examine electrical stimulation and incapacitation with such ultrashort pulses, experiments on anesthetized rats have been performed. The effect of single, 450 nanosecond monopolar pulses have been compared with that of single pulses with multi-microsecond duration (TASER pulses). Two conditions were explored: 1. the ability to elicit a muscle twitch, and, 2. the ability to suppress voluntary movement by using nanosecond pulses. The second condition is relevant for neuromuscular incapacitation. The preliminary results indicate that for stimulation microsecond pulses are advantageous over nanosecond pulses, whereas for incapacitation, the opposite seems to apply. The stimulation effects seem to scale with electrical charge, whereas the disruption effects don't follow a simple scaling law. The increase in intensity (time of incapacitation) for a given pulse duration, is increasing with electrical energy, but is more efficient for nanosecond than for microsecond pulses. This indicates different cellular mechanisms for incapacitation, most likely subcellular processes, which have been shown to become increasingly important when the pulse duration is shortened into the nanosecond range. If further studies can confirm these initial results, consequences of reduced pulse duration are a reduction in weight and volume of the pulse delivery system, and likely, because of the lower required energy for neuromuscular incapacitation, reduced safety risks.

  5. Surgical advances in the treatment of neuromuscular scoliosis

    PubMed Central

    Canavese, Federico; Rousset, Marie; Le Gledic, Benoit; Samba, Antoine; Dimeglio, Alain

    2014-01-01

    Neuromuscular disorders are a group of diseases affecting the neuro-musculo-skeletal system. Children with neuromuscular disorders frequently develop progressive spinal deformities with cardio-respiratory compromise in the most severe cases. The incidence of neuromuscular scoliosis is variable, inversely correlated with ambulatory abilities and with a reported risk ranging from 80% to 100% in non-ambulatory patients. As surgical and peri-operative techniques have improved, more severely affected children with complex neuromuscular deformities and considerable co-morbidities are now believed to be candidates for extensive surgery for spinal deformity. This article aimed to provide a comprehensive review of how neuromuscular spinal deformities can affect normal spine balance and how these deformities can be treated with segmental instrumentation and sub-laminar devices. Older concepts have been integrated with newer scientific data to provide the reader with a basis for better understanding of how treatment of neuromuscular scoliosis has evolved over the past few decades. Recent advances, as well as challenges that remain to be overcome, in the surgical treatment of neuromuscular curves with sub-laminar devices and in the management of post-operative infections are outlined. PMID:24829875

  6. Novel pharmacological approaches for the antagonism of neuromuscular blockade.

    PubMed

    Pic, Lisa C

    2005-02-01

    Gamma cyclodextrin and purified plasma cholinesterase are 2 novel pharmacological agents being investigated as to their suitability for antagonism of neuromuscular blockade. Both of these agents are devoid of cholinergic stimulation and the accompanying side effects because their action is independent of acetylcholinesterase inhibition. Gamma cyclodextrin antagonizes the steroidal neuromuscular blocker rocuronium via the chemical encapsulation of the molecule forming a "host-guest" complex through van der Waals and hydrophobic interactions in the plasma. Encapsulation decreases plasma drug concentrations, shifting the neuromuscular blocking drug molecules from the neuromuscular junction back to the plasma compartment resulting in a rapid recovery of the neuromuscular function. Org 25969, a modified gamma cyclodextrin, will antagonize profound neuromuscular block induced by rocuronium in approximately 2 minutes. A commercial preparation of purified human plasma cholinesterase has been shown to be effective in reversing succinylcholine or mivacurium-induced block. Administration of exogenous plasma cholinesterase also has been shown to be effective in antagonizing mivacurium-induced neuromuscular block, cocaine toxicity, and organophosphate poisoning.

  7. THE ROLE OF THE NEUROMUSCULAR MEDICINE SPECIALIST AND PHYSIATRY IN THE MANAGEMENT OF NEUROMUSCULAR DISEASE

    PubMed Central

    McDonald, Craig M.; Fowler, William M.

    2012-01-01

    Synopsis The neuromuscular medicine, and physiatry specialists are key health care providers who work cooperatively with a multidisciplinary team to provide coordinated care for persons with Neuromuscular diseases (NMDs). The director or coordinator of the team must be aware of the potential issues specific to NMDs and be able to access the interventions that are the foundations for proper care in NMD. These include health maintenance and proper monitoring of disease progression and complications to provide anticipatory, preventive care and optimum management. Ultimate goals include maximizing health and functional capacities, performing medical monitoring and surveillance to inhibit and prevent complications, and promoting access and full integration into the community in order to optimize quality of life. PMID:22938874

  8. Neuromuscular ultrasound findings in polyneuropathy secondary to disulfiram.

    PubMed

    Stone, Sarah L; Cartwright, Michael S; Panea, Oana R; Vann, Ryan C; Magruder, John L; Walker, Francis O

    2014-12-01

    Disulfiram toxicity can cause multiple neurologic problems, including a reversible distal sensorimotor axonal polyneuropathy. Although electrodiagnosis and biopsy results have been described in the diagnosis and management of patients with disulfiram associated polyneuropathy, neuromuscular ultrasound findings have not been reported. The authors present a case of electrodiagnostically confirmed axonal polyneuropathy with relative sural sparing secondary to disulfiram and describe the neuromuscular ultrasound findings in this individual. Ultrasound demonstrated distal enlargement with slight side-to-side asymmetry and normal proximal cross-sectional area in the lower extremity nerves. Neuromuscular ultrasound is another diagnostic modality that may be used to assist in the diagnosis of patients with polyneuropathy secondary to disulfiram.

  9. Central enhancement of evoked electromyographic monitoring of neuromuscular function.

    PubMed

    Smith, D C

    1991-05-01

    Central neural influences on neuromuscular transmission may explain the frequent failure of evoked electromyographic (EEMG) responses to return to control values during offset of neuromuscular block. This study, performed in conscious subjects, did not demonstrate any change in EEMG response of either the first dorsal interosseous muscle during onset of ulnar nerve block or the flexor hallucis brevis during onset of subarachnoid block. It is concluded that central enhancement of EEMG response via a neural mechanism does not explain the observed failure of EEMG monitoring of neuromuscular block.

  10. Central enhancement of evoked electromyographic monitoring of neuromuscular function.

    PubMed

    Smith, D C

    1991-05-01

    Central neural influences on neuromuscular transmission may explain the frequent failure of evoked electromyographic (EEMG) responses to return to control values during offset of neuromuscular block. This study, performed in conscious subjects, did not demonstrate any change in EEMG response of either the first dorsal interosseous muscle during onset of ulnar nerve block or the flexor hallucis brevis during onset of subarachnoid block. It is concluded that central enhancement of EEMG response via a neural mechanism does not explain the observed failure of EEMG monitoring of neuromuscular block. PMID:1851627

  11. Wnt Signaling in Neuromuscular Junction Development

    PubMed Central

    Koles, Kate

    2012-01-01

    Wnt proteins are best known for their profound roles in cell patterning, because they are required for the embryonic development of all animal species studied to date. Besides regulating cell fate, Wnt proteins are gaining increasing recognition for their roles in nervous system development and function. New studies indicate that multiple positive and negative Wnt signaling pathways take place simultaneously during the formation of vertebrate and invertebrate neuromuscular junctions. Although some Wnts are essential for the formation of NMJs, others appear to play a more modulatory role as part of multiple signaling pathways. Here we review the most recent findings regarding the function of Wnts at the NMJ from both vertebrate and invertebrate model systems. PMID:22510459

  12. Neuromuscular junction in a microfluidic device.

    PubMed

    Park, Hyun Sung; Liu, Su; McDonald, John; Thakor, Nitish; Yang, In Hong

    2013-01-01

    Malfunctions at the site of neuromuscular junction (NMJ) of post-injuries or diseases are major barriers to recovery of function. The ability to efficiently derive motor neurons (MN) from embryonic stem cells has indicated promise toward the development of new therapies in increasing functional outcomes post injury. Recent advances in micro-technologies have provided advanced culture platforms allowing compartmentalization of sub-cellular components of neurons. In this study, we combined these advances in science and technology to develop a compartmentalized in vitro NMJ model. The developed NMJ system is between mouse embryonic stem cell (mESC)-derived MNs and c2c12 myotubes cultured in a compartmentalized polydimethylsiloxane (PDMS) microfluidic device. While some functional in vitro NMJ systems have been reported, this system would further contribute to research in NMJ-related diseases by providing a system to study the site of action of NMJ aimed at improving promoting better functional recovery. PMID:24110317

  13. Load-dependent regulation of neuromuscular system

    NASA Technical Reports Server (NTRS)

    Ohira, Yoshinobu; Kawano, Fuminori; Stevens, James L.; Wang, Xiao D.; Ishihara, Akihiko

    2004-01-01

    Roles of gravitational loading, sarcomere length, and/or tension development on the electromyogram (EMG) of soleus and afferent neurogram recorded at the L5 segmental level of spinal cord were investigated during parabolic flight of a jet airplane or hindlimb suspension in conscious rats. Both EMG and neurogram levels were increased when the gravity levels were elevated from 1-G to 2-G during the parabolic flight. They were decreased when the hindlimbs were unloaded by exposure to actual microgravity or by suspension. These phenomena were related to passive shortening of muscle fibers and/or sarcomeres. Unloading-related decrease in sarcomere length was greater at the central rather than the proximal and distal regions of fibers. These activities and tension development were not detected when the mean sarcomere length was less than 2.03 micrometers. It is suggested that load-dependent regulation of neuromuscular system is related to the tension development which is influenced by sarcomere length.

  14. Neuromuscular Impairment Following Backpack Load Carriage

    PubMed Central

    Blacker, Sam D.; Fallowfield, Joanne L.; Bilzon, James L.J.; Willems, Mark E.T.

    Load Carriage using backpacks is an occupational task and can be a recreational pursuit. The aim of this study was to investigate the mechanisms responsible for changes in neuromuscular function of the m. quadriceps femoris following load carriage. The physiological responses of 10 male participants to voluntary and electrically stimulated isometric contractions were measured before and immediately after two hours of treadmill walking at 6.5 km•h −1 during level walking with no load [LW], and level walking with load carriage (25 kg backpack) [LC]. Maximal voluntary contraction force decreased by 15 ± 11 % following LC (p=0.006), with no change following LW (p=0.292). Voluntary activation decreased after LW and LC (p=0.033) with no difference between conditions (p=0.405). Doublet contraction time decreased after both LW and LC (p=0.002), with no difference between conditions (p=0.232). There were no other changes in electrically invoked doublet parameters in either condition. The 20:50 Hz ratio did not change following LW (p=0.864) but decreased from 0.88 ± 0.04 to 0.84 ± 0.04 after LC (p=0.011) indicating reduced Ca2+ release from the sarcoplasmic reticulum during excitation contraction coupling. In conclusion, two hours of load carriage carrying a 25 kg back pack caused neuromuscular impairment through a decrease in voluntary activation (i.e. central drive) and fatigue or damage to the peripheral muscle, including impairment of the excitation contraction coupling process. This may reduce physical performance and increase the risk of musculoskeletal injury. PMID:24146709

  15. Visual and tactile assessment of neuromuscular fade.

    PubMed

    Brull, S J; Silverman, D G

    1993-08-01

    The accuracy of visual and tactile assessment of the neuromuscular fade in response to train-of-four (TOF) and double-burst stimulation (DBS) were compared to assess their relative utility in the clinical setting. For each of 74 data sets with a mechanographic TOF ratio less than 0.70, an observer (blinded to the presence or degree of fade) performed visual and tactile assessments of fade in response to TOF, DBS3,3, and DBS3,2 stimuli at low current (20 and 30 mA) and high current (50 and 60 mA). For the range of mechanographic TOF ratios between 0.41 and 0.70, visual assessment failed to identify TOF, DBS3,3, and DBS3,2 fade in 46%, 18%, and 14% of cases at high current and in 23%, 5%, and 0% of cases at low current, respectively. Tactile assessments failed to identify fade in 55%, 23%, and 14% of cases at high current and in 23%, 14%, and 14% of cases at low current. Overall, the ability to detect fade was comparable for visual and tactile assessments regardless of the method of neurostimulation (P = NS with paired t-test). However, the degree of overestimation of the fade ratio (i.e., quantitative assessment) tended to be less when using tactile means; the difference achieved significance for TOF at low current and DBS3,3 at both low and high currents. We conclude that the differences between the visual and tactile means of assessment are relatively small compared to the differences among the TOF and DBS patterns of neurostimulation. Both subjective techniques are often inadequate in settings in which assurance of full recovery of neuromuscular function is critical.

  16. Explosive neuromuscular performance of males versus females.

    PubMed

    Hannah, Ricci; Minshull, Claire; Buckthorpe, Matthew W; Folland, Jonathan P

    2012-05-01

    The purpose of the study was to investigate sex-related differences in explosive muscular force production, as measured by electromechanical delay (EMD) and rate of force development (RFD), and to examine the physiological mechanisms responsible for any differences. The neuromuscular performance of untrained males (n = 20) and females (n = 20) was assessed during a series of isometric knee extension contractions; explosive and maximal voluntary efforts, as well as supramaximal evoked twitches and octets (eight pulses at 300 Hz). Evoked and voluntary EMD were determined from twitch and explosive contractions. The RFD was recorded over consecutive 50 ms time windows from force onset during evoked and explosive contractions, and normalized to maximal strength. Neuromuscular activity during explosive voluntary contractions was measured with EMG of the superficial knee extensors normalized to maximal M-wave. Muscle size (thickness) and muscle-tendon unit (MTU) stiffness were assessed using ultrasonic images of the vastus lateralis at rest and during ramped contractions. Males and females had similar evoked and voluntary EMD. Males were 33% stronger (P < 0.001) and their absolute RFD was 26-56% greater (all time points P < 0.05) compared with females. Muscle size (P < 0.001) and absolute MTU stiffness were also greater for males (P < 0.05). However, normalized RFD was similar for both sexes during the first 150 ms of the explosive voluntary contractions (P > 0.05). This was consistent with the similar normalized twitch and octet RFD, MTU stiffness and agonist EMG (all P > 0.05). When differences in maximal strength were accounted for, the evoked capacity of the knee extensors for explosive force production and the ability to utilize that capacity during explosive voluntary contractions was similar for males and females.

  17. Cardiorespiratory and neuromuscular responses to motocross riding.

    PubMed

    Konttinen, Tomi; Kyröläinen, Heikki; Häkkinen, Keijo

    2008-01-01

    The aim of the present study was to examine physiological and neuromuscular responses during motocross riding at individual maximal speed together with the riding-induced changes in maximal isometric force production. Seven A-level (group A) and 5 hobby-class (group H) motocross-riders performed a 30-minute riding test on a motocross track and maximal muscle strength and oxygen uptake (VO2max) tests in a laboratory. During the riding the mean (+/-SD) VO2 reduced in group A from 86 +/- 10% to 69 +/- 6% of the maximum (P < 0.001), whereas in group H the corresponding reduction was from 94 +/- 25% to 82 +/- 20% (P < 0.05). This relative VO2 during the riding correlated with riding speed (r = 0.70, P < 0.01). Heart rate (HR) was maintained at the level of 97 +/- 7% of its maximum in group A and at 98 +/- 3% in group H. Mean muscle activation of the lower body during riding varied between 24% and 38% of its maximum in group A and between 40% and 45% in group H. In conclusion, motocross is a sport that causes great physical stress and demands on both skill and physical capacity of the rider. Physical stress occurs as the result of handling of the bike when receiving continuous impacts in the situation requiring both aerobic and anaerobic metabolism. Our data suggest that both maximal capacity and strain during the ride should be measured to analyze the true physiological and neuromuscular demands of motocross ride. For the practice, this study strongly suggests to train not only aerobic and anaerobic capacity but also to use strength and power training for successful motocross riding. PMID:18296976

  18. Mechanism of Neuromuscular Dysfunction in Krabbe Disease

    PubMed Central

    Cantuti-Castelvetri, Ludovico; Maravilla, Erick; Marshall, Michael; Tamayo, Tammy; D'auria, Ludovic; Monge, John; Jeffries, James; Sural-Fehr, Tuba; Lopez-Rosas, Aurora; Li, Guannan; Garcia, Kelly; van Breemen, Richard; Vite, Charles; Garcia, Jesus

    2015-01-01

    The atrophy of skeletal muscles in patients with Krabbe disease is a major debilitating manifestation that worsens their quality of life and limits the clinical efficacy of current therapies. The pathogenic mechanism triggering muscle wasting is unknown. This study examined structural, functional, and metabolic changes conducive to muscle degeneration in Krabbe disease using the murine (twitcher mouse) and canine [globoid cell leukodystrophy (GLD) dog] models. Muscle degeneration, denervation, neuromuscular [neuromuscular junction (NMJ)] abnormalities, and axonal death were investigated using the reporter transgenic twitcher–Thy1.1–yellow fluorescent protein mouse. We found that mutant muscles had significant numbers of smaller-sized muscle fibers, without signs of regeneration. Muscle growth was slow and weak in twitcher mice, with decreased maximum force. The NMJ had significant levels of activated caspase-3 but limited denervation. Mutant NMJ showed reduced surface areas and lower volumes of presynaptic terminals, with depressed nerve control, increased miniature endplate potential (MEPP) amplitude, decreased MEPP frequency, and increased rise and decay rate constants. Twitcher and GLD dog muscles had significant capacity to store psychosine, the neurotoxin that accumulates in Krabbe disease. Mechanistically, muscle defects involved the inactivation of the Akt pathway and activation of the proteasome pathway. Our work indicates that muscular dysfunction in Krabbe disease is compounded by a pathogenic mechanism involving at least the failure of NMJ function, activation of proteosome degradation, and a reduction of the Akt pathway. Akt, which is key for muscle function, may constitute a novel target to complement in therapies for Krabbe disease. PMID:25632136

  19. Neuromuscular Evaluation of Trunk-Training Exercises

    PubMed Central

    Schmitz, Klaus; Denner, Achim

    2001-01-01

    Objective: To evaluate the neuromuscular activation profiles of trunk muscles in commonly used gymnastic strength exercises with a polymyographic set-up and to describe the training effects of each exercise. Design and Setting: Subjects performed 9 repetitions of each of 12 gymnastic exercises. Variations of 5 trunk flexions, 5 extensions, and 2 lateral-flexion movements were performed under standardized test conditions. Subjects: Ten healthy subjects (men and women) who were familiar with the exercises participated in the study. Measurements: We recorded surface electromyograms (EMGs) from the rectus abdominis, external oblique, rectus femoris, middle trapezius, erector spinae at T12 and L3, gluteus maximus, and semitendinosus and semimembranosus muscles. Recording of each repetition cycle was triggered by a flexible electronic goniometer attached to the trunk. The raw EMG signals were rectified, smoothed, amplitude normalized to maximal voluntary contraction (MVC), and averaged for the last 8 repetitions. Results: Pure spine-flexion exercises, such as a curl-up, produced sufficient and isolated activation (greater than 50% MVC) of the abdominal muscles. When flexion of the spine was combined with hip flexion (sit-up), the peak activation was increased. Lateral-flexion tasks targeted primarily the external oblique muscle, which demonstrated high activity in side-lying flexion tasks. Back- and hip-extension exercises, such as bridging and diagonal hip and shoulder extension, produced only moderate mean activities (less than 35% MVC) in the trunk-extensor muscles. Trunk-extension exercises with combined hip extension increased the EMG activity to 50% MVC but only at the end of the extension. Conclusions: Individual responses to each exercise varied markedly, which complicated the classification of exercise effects. However, within the limitations of the study, we found that the chosen abdominal exercises provided an effective training stimulus for the trunk

  20. Teaching Visually Impaired Adults with a Neuromuscular Disorder.

    ERIC Educational Resources Information Center

    Williams, Susan

    1983-01-01

    The effects of four neuromuscular disorders (stroke, Parkinson's disease, Huntington's disease, and Lou Gehrig's disease) on concommitant visual impairments are considered. Rehabilitation approaches and equipment that help clients cope with the condition are described. (CL)

  1. Anaphylactic reactions during anaesthesia: neuromuscular blocking agents, latex and antibiotics.

    PubMed

    2013-05-01

    A French team investigated hypersensitivity reactions that occurred during locoregional or general anaesthesia over an 8-year period. They estimated that the incidence of anaphylactic reactions was about 1 per 10 000 anaesthetic procedures. Among the 1816 reports of anaphylactic reactions, the most commonly implicated drugs were neuromuscular blocking agents (1067 cases), latex (361 cases), and antibiotics (236 cases). Some anaphylactic reactions to neuromuscular blocking agents occurred in patients who had never previously been anaesthetised, suggesting cross-reactivity with other, poorly known, substances. Most reactions in children were due to latex, followed by neuromuscular blocking agents and antibiotics. In practice, exposure to latex devices should be minimised, or simply avoided when possible. A history of sensitization to substances sharing allergenic sites with neuromuscular blocking agents should be investigated, and measures should be taken to protect patients.

  2. Genetics of Pediatric-Onset Motor Neuron and Neuromuscular Diseases

    ClinicalTrials.gov

    2015-08-24

    Spinal Muscular Atrophy; Charcot-Marie-Tooth Disease; Muscular Dystrophy; Spinal Muscular Atrophy With Respiratory Distress 1; Amyotrophic Lateral Sclerosis; Motor Neuron Disease; Neuromuscular Disease; Peroneal Muscular Atrophy; Fragile X Syndrome

  3. 21 CFR 882.5860 - Implanted neuromuscular stimulator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Date PMA or notice of completion of PDP is required. A PMA or notice of completion of a PDP for a.... Any other implanted neuromuscular stimulator shall have an approved PMA or declared completed PDP...

  4. The potential of disease management for neuromuscular hereditary disorders.

    PubMed

    Chouinard, Maud-Christine; Gagnon, Cynthia; Laberge, Luc; Tremblay, Carmen; Côté, Charlotte; Leclerc, Nadine; Mathieu, Jean

    2009-01-01

    Neuromuscular hereditary disorders require long-term multidisciplinary rehabilitation management. Although the need for coordinated healthcare management has long been recognized, most neuromuscular disorders are still lacking clinical guidelines about their long-term management and structured evaluation plan with associated services. One of the most prevalent adult-onset neuromuscular disorders, myotonic dystrophy type 1, generally presents several comorbidities and a variable clinical picture, making management a constant challenge. This article presents a healthcare follow-up plan and proposes a nursing case management within a disease management program as an innovative and promising approach. This disease management program and model consists of eight components including population identification processes, evidence-based practice guidelines, collaborative practice, patient self-management education, and process outcomes evaluation (Disease Management Association of America, 2004). It is believed to have the potential to significantly improve healthcare management for neuromuscular hereditary disorders and will prove useful to nurses delivering and organizing services for this population.

  5. Preparing for Emergencies: A Checklist for People with Neuromuscular Diseases

    MedlinePlus

    TORNADO • FLASH FLOOD • EARTHQUAKE • WINTER STORM • HURRICANE • FIRE • HAZARDOUS MATERIALS SPILL Preparing for Emergencies A Checklist for People with Neuromuscular Diseases F or the millions of Americans with limited ...

  6. The role of proprioception and neuromuscular stability in carpal instabilities.

    PubMed

    Hagert, E; Lluch, A; Rein, S

    2016-01-01

    Carpal stability has traditionally been defined as dependent on the articular congruity of joint surfaces, the static stability maintained by intact ligaments, and the dynamic stability caused by muscle contractions resulting in a compression of joint surfaces. In the past decade, a fourth factor in carpal stability has been proposed, involving the neuromuscular and proprioceptive control of joints. The proprioception of the wrist originates from afferent signals elicited by sensory end organs (mechanoreceptors) in ligaments and joint capsules that elicit spinal reflexes for immediate joint stability, as well as higher order neuromuscular influx to the cerebellum and sensorimotor cortices for planning and executing joint control. The aim of this review is to provide an understanding of the role of proprioception and neuromuscular control in carpal instabilities by delineating the sensory innervation and the neuromuscular control of the carpus, as well as descriptions of clinical applications of proprioception in carpal instabilities. PMID:26115684

  7. Muscle ultrasound quantifies segmental neuromuscular outcome in pediatric myelomeningocele.

    PubMed

    Verbeek, Renate J; Hoving, Eelco W; Maurits, Natalia M; Brouwer, Oebele F; van der Hoeven, Johannes H; Sival, Deborah A

    2014-01-01

    In pediatric spina bifida aperta (SBA), non-invasive assessment of neuromuscular integrity by muscle ultrasound density (MUD) could provide important information about the clinical condition. We therefore aimed to determine the association between pediatric SBA MUD and segmental neurologic function. We included 23 children (age range: 1-18 y) with SBA with L4-5 lesions, and we associated SBA MUD with control values and segmental neuromuscular function. Results revealed that MUD outcomes in the lower extremities: (i) are independent of age, (ii) exceed control values, (iii) differ intra-individually (i.e., between the left and right sides in the same individual) in association with segmental neuromuscular function. We concluded that SBA leg MUD can quantify the segmental neuromuscular condition throughout childhood.

  8. Neuromuscular blockade: what was, is and will be.

    PubMed

    Schepens, Tom; Cammu, Guy

    2014-01-01

    Non-depolarizing neuromuscular blocking agents (NMBAs) produce neuromuscular blockade by competing with acetylcholine at the neuromuscular junction, whereas depolarizing NMBAs open receptor channels in a manner similar to that of acetylcholine. Problems with NMBAs include malignant hyperthermia caused by succinylcholine, anaphylaxis with the highest incidence for succinylcholine and rocuronium, and residual neuromuscular blockade. To reverse these blocks, anticholinesterases can act indirectly by increasing the amount of acetylcholine in the neuromuscular junction; sugammadex is the only selective relaxant binding agent (SRBA) in clinical use. At all levels of blockade, recovery after sugammadex is faster than after neostigmine. Sugammadex potentially also has some other advantages over neostigmine that are related to neostigmine's increase in the amount of acetylcholine and the necessity of co-administering anticholinergics. However, hypersensitivity reactions, including anaphylaxis, have occurred in some patients and healthy volunteers after sugammadex and remain an issue for the FDA. In the near future, we may see the emergence of new SRBAs and of easier-to-use technologies that can routinely monitor neuromuscular transmissions in daily practice. The nature of the effect of sugammadex on freeing nicotinic acetylcholine receptors located outside the neuromuscular junction from NMBAs is unknown. Moreover, it is uncertain whether the full removal of the competing antagonists (by SRBAs) at the neuromuscular junction impacts the efficiency of acetylcholine transmission. In a recent pilot study in healthy volunteers, we demonstrated increased electromyographic diaphragm activity after sugammadex, compared to neostigmine. Further research is needed to elucidate the role of NMBAs and their reversal agents in the central control of breathing, respiratory muscle activity, and respiratory outcomes. PMID:25622380

  9. Neuromuscular Fatigue During 200 M Breaststroke

    PubMed Central

    Conceição, Ana; Silva, António J.; Barbosa, Tiago; Karsai, István; Louro, Hugo

    2014-01-01

    The aims of this study were: i) to analyze activation patterns of four upper limb muscles (duration of the active and non-active phase) in each lap of 200m breaststroke, ii) quantify neuromuscular fatigue, with kinematics and physiologic assessment. Surface electromyogram was collected for the biceps brachii, deltoid anterior, pectoralis major and triceps brachii of nine male swimmers performing a maximal 200m breaststroke trial. Swimming speed, SL, SR, SI decreased from the 1st to the 3rd lap. SR increased on the 4th lap (35.91 ± 2.99 stroke·min-1). Peak blood lactate was 13.02 ± 1.72 mmol·l-1 three minutes after the maximal trial. The EMG average rectified value (ARV) increased at the end of the race for all selected muscles, but the deltoid anterior and pectoralis major in the 1st lap and for biceps brachii, deltoid anterior and triceps brachii in the 4th lap. The mean frequency of the power spectral density (MNF) decreased at the 4th lap for all muscles. These findings suggest the occurrence of fatigue at the beginning of the 2nd lap in the 200m breaststroke trial, characterized by changes in kinematic parameters and selective changes in upper limb muscle action. There was a trend towards a non-linear fatigue state. Key Points Fatigue in the upper limbs occurs in different way as it described by 100m swimming events. Neuromuscular fatigue was estimated by analyzing the physiological changes (high blood lactate concentrations), biomechanical changes in the swimming stroke characteristics (decreased in swimming velocity), and by the changes in the EMG amplitude and frequency parameters at the end of the swimming bout. The amplitude signal of EMG provided by the ARV demonstrated an increase at the end with the respect to the beginning for all muscles under study, excepted for the muscle deltoid anterior. The mean frequency (MNF) in our study decrease at the end of the swimming in the 4th lap relative to the 1st lap for all muscles under observation, along the

  10. Animal models for genetic neuromuscular diseases.

    PubMed

    Vainzof, Mariz; Ayub-Guerrieri, Danielle; Onofre, Paula C G; Martins, Poliana C M; Lopes, Vanessa F; Zilberztajn, Dinorah; Maia, Lucas S; Sell, Karen; Yamamoto, Lydia U

    2008-03-01

    The neuromuscular disorders are a heterogeneous group of genetic diseases, caused by mutations in genes coding sarcolemmal, sarcomeric, and citosolic muscle proteins. Deficiencies or loss of function of these proteins leads to variable degree of progressive loss of motor ability. Several animal models, manifesting phenotypes observed in neuromuscular diseases, have been identified in nature or generated in laboratory. These models generally present physiological alterations observed in human patients and can be used as important tools for genetic, clinic, and histopathological studies. The mdx mouse is the most widely used animal model for Duchenne muscular dystrophy (DMD). Although it is a good genetic and biochemical model, presenting total deficiency of the protein dystrophin in the muscle, this mouse is not useful for clinical trials because of its very mild phenotype. The canine golden retriever MD model represents a more clinically similar model of DMD due to its larger size and significant muscle weakness. Autosomal recessive limb-girdle MD forms models include the SJL/J mice, which develop a spontaneous myopathy resulting from a mutation in the Dysferlin gene, being a model for LGMD2B. For the human sarcoglycanopahties (SG), the BIO14.6 hamster is the spontaneous animal model for delta-SG deficiency, whereas some canine models with deficiency of SG proteins have also been identified. More recently, using the homologous recombination technique in embryonic stem cell, several mouse models have been developed with null mutations in each one of the four SG genes. All sarcoglycan-null animals display a progressive muscular dystrophy of variable severity and share the property of a significant secondary reduction in the expression of the other members of the sarcoglycan subcomplex and other components of the Dystrophin-glycoprotein complex. Mouse models for congenital MD include the dy/dy (dystrophia-muscularis) mouse and the allelic mutant dy(2J)/dy(2J) mouse

  11. Sevoflurane enhances neuromuscular blockade by increasing the sensitivity of skeletal muscle to neuromuscular blockers

    PubMed Central

    Ye, Ling; Zuo, Yunxia; Zhang, Peng; Yang, Pingliang

    2015-01-01

    The aim of this study was to investigate the effects of sevoflurane on skeletal muscle contractility. In the first part, twenty-two American Society of Anesthesiology (ASA I-II) female adult patients undergoing elective hysterectomy surgery inhaled sevoflurane 1.0, 1.5 and 2.0 minimum alveolar concentrations (MAC) in succession. Neuromuscular function was assessed at each dose. In the second part, forty-four ASA I-II female adult patients were randomized into four groups: group 1 (propofol + atracurium, sevoflurane 0 MAC), and groups 2 to 4 (atracurium + sevoflurane 1.0, 1.5 and 2.0 MAC, respectively). In group 1, patients were anesthetized by propofol. Then 0.01 mg/kg atracurium was injected into the tested arm intravenously after the arterial blood flow was blocked using a tourniquet. For the other 3 groups, patients inhaled 1.0 MAC, 1.5 MAC, or 2.0 MAC of sevoflurane. Then 0.01 mg/kg atracurium was injected. Neuromuscular function was recorded for the 4 groups. Neuromuscular function was assessed by acceleromyography measurement of evoked responses to train-of four (TOF) stimuli (2 Hz for 2 s applied every 12 s) at the adductor pollicis using a TOF-GuardTM neuromuscular transmission monitor. Amplitudes of first response (T1) in each TOF sequence and the ratios of fourth TOF response (T4) to the first were similar at 1.0 MAC, 1.5 MAC, and 2.0 MAC sevoflurane. Compared to baseline, there was no significant change in the TOF value after inhaling 1.0 MAC, 1.5 MAC, or 2.0 MAC sevoflurane. Compared to group 1, there was no significant difference in atracurium onset time (time to reach TOF ratio = 0.25) in group 2 ( 5.6 ± 1.8 min vs. 6.5 ± 1.7 min, P>0.05), or degree of adductor pollicis block (subject number with TOF ratio = 0, 5 vs. 2 subjects, p = 0.3). However, inhaling 1.5 or 2.0 MAC sevoflurane decreased atracurium onset time (4.6 ± 1.5 min and 4.0 ± 1.3 min vs. 6.5 ± 1.7 min, P<0.01 and P<0.001, respectively), and enhanced the block degree (9 and 10 vs. 2

  12. Neuromuscular dentistry: Occlusal diseases and posture

    PubMed Central

    Khan, Mohd Toseef; Verma, Sanjeev Kumar; Maheshwari, Sandhya; Zahid, Syed Naved; Chaudhary, Prabhat K.

    2013-01-01

    Neuromuscular dentistry has been a controversial topic in the field of dentistry and still remains debatable. The issue of good occlusion and sound health has been repeatedly discussed. Sometimes we get complains of sensitive teeth and sometimes of tired facial muscles on getting up in the morning. Owing to the intimate relation of masticatory apparatus with the cranium and cervico-scapular muscular system, the disorders in any system, draw attention from concerned clinicians involved in management, to develop an integrated treatment protocol for the suffering patients. There may be patients reporting to the dental clinics after an occlusal restoration or extraction, having pain in or around the temporomandibular joint, headache or neck pain. Although their esthetic demands must not be undermined during the course of treatment plan, whenever dental treatment of any sort is planned, occlusion/bite should be given prime importance. Very few dentist are able to diagnose the occlusal disease and of those who diagnose many people resort to aggressive treatment modalities. This paper aims to report the signs of occlusal disease, and discuss their association with TMDs and posture. PMID:25737904

  13. Neuromuscular performance characteristics in elite female athletes.

    PubMed

    Huston, L J; Wojtys, E M

    1996-01-01

    The purpose of this research was to identify possible predisposing neuromuscular factors for knee injuries, particularly anterior cruciate ligament tears in female athletes by investigating anterior knee laxity, lower extremity muscle strength, endurance, muscle reaction time, and muscle recruitment order in response to anterior tibial translation. We recruited four subject groups: elite female (N = 40) and male (N = 60) athletes and sex-matched nonathletic controls (N = 40). All participants underwent a subjective evaluation of knee function, arthrometer measurement of anterior tibial translation, isokinetic dynamometer strength and endurance tests at 60 and 240 deg/sec, and anterior tibial translation stress tests. Dynamic stress testing of muscles demonstrated less anterior tibial translation in the knees of the athletes (both men and women) compared with the nonathletic controls. Female athletes and controls demonstrated more anterior tibial laxity than their male counterparts and significantly less muscle strength and endurance. Compared with the male athletes, the female athletes took significantly longer to generate maximum hamstring muscle torque during isokinetic testing. Although no significant differences were found in either spinal or cortical muscle reaction times, the muscle recruitment order in some female athletes was markedly different. The female athletes appeared to rely more on their quadriceps muscles in response to anterior tibial translation; the three other test groups relied more on their hamstring muscles for initial knee stabilization.

  14. The neuromuscular differential diagnosis of joint hypermobility.

    PubMed

    Donkervoort, S; Bonnemann, C G; Loeys, B; Jungbluth, H; Voermans, N C

    2015-03-01

    Joint hypermobility is the defining feature of various inherited connective tissue disorders such as Marfan syndrome and various types of Ehlers-Danlos syndrome and these will generally be the first conditions to be considered by geneticists and pediatricians in the differential diagnosis of a patient presenting with such findings. However, several congenital and adult-onset inherited myopathies also present with joint hypermobility in the context of often only mild-to-moderate muscle weakness and should, therefore, be included in the differential diagnosis of joint hypermobility. In fact, on the molecular level disorders within both groups represent different ends of the same spectrum of inherited extracellular matrix (ECM) disorders. In this review we will summarize the measures of joint hypermobility, illustrate molecular mechanisms these groups of disorders have in common, and subsequently discuss the clinical features of: 1) the most common connective tissue disorders with myopathic or other neuromuscular features: Ehlers-Danlos syndrome, Marfan syndrome and Loeys-Dietz syndrome; 2) myopathy and connective tissue overlap disorders (muscle extracellular matrix (ECM) disorders), including collagen VI related dystrophies and FKBP14 related kyphoscoliotic type of Ehlers-Danlos syndrome; and 3) various (congenital) myopathies with prominent joint hypermobility including RYR1- and SEPN1-related myopathy. The aim of this review is to assist clinical geneticists and other clinicians with recognition of these disorders. PMID:25821091

  15. Effects of aminoglycoside antibiotics on the neuromuscular junction: Part I.

    PubMed

    Yamada, S; Kuno, Y; Iwanaga, H

    1986-03-01

    The effects of aminoglycoside antibiotics (AGA) including streptomycin (SM), kanamycin (KM), gentamicin (GM), dibekacin (DKB), amikacin (AMK) and sisomycin (SISO), on the neuromuscular junction were studied by in vivo and in vitro experiments. In in vitro experiments, no effect of AGA on rat phrenic nerve diaphragm preparations was observed, but the use of the antibiotics at a high concentration exerted a slight blocking effect on the neuromuscular junction. The blocking effect of SISO and DKB on the neuromuscular junction was marked. These antibiotics were definitely found to compete with eserine in terms of the blocking effect on the neuromuscular junction, but did not compete with calcium chloride. In in vitro experiments with frog sciatic nerve and musculus sartorius preparations, DKB and SISO exerted a blocking effect on the NMJ, inducing the disappearance of action potentials and the appearance of endplate potentials (EPPs). In in vitro experiments with the preparations from Rana catesbiana frogs, SM, GM, DKB and SISO exhibited an inhibiting effect on the release of acetylcholine (ACh), a chemical neurotransmitter in neuromuscular junction, resulting in a decrease in the frequency of miniature endplate potentials (mEPPS). In in vivo experiments with rabbit sciatic tibialis anterior muscle preparations, SM, GM, DKB and SISO exerted a blocking effect on the neuromuscular junction. From the facts that the effect was augmented by the use of magnesium chloride combined with these antibiotics and that the antibiotics competed with calcium chloride and potassium chloride in terms of the blocking effect on the neuromuscular junction, the effects seemed to be due to the inhibition of ACh release.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3699939

  16. Lumbopelvic flexibility modulates neuromuscular responses during trunk flexion-extension.

    PubMed

    Sánchez-Zuriaga, Daniel; Artacho-Pérez, Carla; Biviá-Roig, Gemma

    2016-06-01

    Various stimuli such as the flexibility of lumbopelvic structures influence the neuromuscular responses of the trunk musculature, leading to different load sharing strategies and reflex muscle responses from the afferents of lumbopelvic mechanoreceptors. This link between flexibility and neuromuscular response has been poorly studied. The aim of this study was to investigate the relationship between lumbopelvic flexibility and neuromuscular responses of the erector spinae, hamstring and abdominal muscles during trunk flexion-extension. Lumbopelvic movement patterns were measured in 29 healthy women, who were separated into two groups according to their flexibility during trunk flexion-extension. The electromyographic responses of erector spinae, rectus abdominis and biceps femoris were also recorded. Subjects with greater lumbar flexibility had significantly less pelvic flexibility and vice versa. Subjects with greater pelvic flexibility had a higher rate of relaxation and lower levels of hamstring activation during maximal trunk flexion. The neuromuscular response patterns of the hamstrings seem partially modulated by pelvic flexibility. Not so with the lumbar erector spinae and lumbar flexibility, despite the assertions of some previous studies. The results of this study improve our knowledge of the relationships between trunk joint flexibility and neuromuscular responses, a relationship which may play a role in low back pain. PMID:27155332

  17. Lumbopelvic flexibility modulates neuromuscular responses during trunk flexion-extension.

    PubMed

    Sánchez-Zuriaga, Daniel; Artacho-Pérez, Carla; Biviá-Roig, Gemma

    2016-06-01

    Various stimuli such as the flexibility of lumbopelvic structures influence the neuromuscular responses of the trunk musculature, leading to different load sharing strategies and reflex muscle responses from the afferents of lumbopelvic mechanoreceptors. This link between flexibility and neuromuscular response has been poorly studied. The aim of this study was to investigate the relationship between lumbopelvic flexibility and neuromuscular responses of the erector spinae, hamstring and abdominal muscles during trunk flexion-extension. Lumbopelvic movement patterns were measured in 29 healthy women, who were separated into two groups according to their flexibility during trunk flexion-extension. The electromyographic responses of erector spinae, rectus abdominis and biceps femoris were also recorded. Subjects with greater lumbar flexibility had significantly less pelvic flexibility and vice versa. Subjects with greater pelvic flexibility had a higher rate of relaxation and lower levels of hamstring activation during maximal trunk flexion. The neuromuscular response patterns of the hamstrings seem partially modulated by pelvic flexibility. Not so with the lumbar erector spinae and lumbar flexibility, despite the assertions of some previous studies. The results of this study improve our knowledge of the relationships between trunk joint flexibility and neuromuscular responses, a relationship which may play a role in low back pain.

  18. Pain in Youths With Neuromuscular Disease

    PubMed Central

    Engel, Joyce M.; Kartin, Deborah; Carter, Gregory T.; Jensen, Mark P.; Jaffe, Kenneth M.

    2011-01-01

    To examine the prevalence and characteristics of pain in children with neuromuscular disease (NMD), 42 youths with NMD underwent a comprehensive evaluation including a detailed intake interview and structured questionnaire that included demographic and functional data. Youths who reported chronic pain were further queried about pain characteristics, locations, and intensity using an 11-point numerical rating scale and a modified Brief Pain Inventory (BPI). The sample consisted of 24 males (57%) and 18 females (43%), ages ranging from 9 to 20 years (M = 14.8, SD = 2.96). Participants included 14 (37%) with Duchenne-muscular dystrophy, 6 (14%) with myotonic dystrophy, 2 (5%) with Becker dystrophy, 2 (5%) with limb-girdle dystrophy, 2 (5%) with congenital muscular dystrophy, 1 (2%) facioscapulohumeral, and 15 (36%) were classified as “other NMD.” Twenty-one (50%) were ambulatory; 26 (62%) used power wheelchairs/scooters, 9 (2%) used manual wheelchairs, 3 (.07%) used crutches/canes, and 1 (2%) used a walker. A total of 23 (55%) of the youths reported having chronic pain. Current pain intensity was 1.30(range=0–6), mean pain intensity over the past week was 2.39 (range = 0–7), mean pain duration was 8.75 hours (SD=12.84). Pain in the legs was most commonly reported and 83% reported using pain medications. This study indicates that chronic pain is a significant problem in youths with NMD. These data strongly support making comprehensive pain assessment and management an integral part of the standard of care for youths with NMD. PMID:19820205

  19. Neuromuscular junction channelopathies: a brief overview.

    PubMed

    Newsom-Davis, John

    2005-12-01

    The neuromuscular junction lacks the protection of the blood-nerve barrier and is vulnerable to antibody-mediated disorders. In myasthenia gravis (MG), 85% of patients have IgG antibodies to acetylcholine receptors (AChRs). About half the remaining patients have IgG antibodies to Muscle Specific Kinase (MuSK), an AChR-associated transmembrane post-synaptic protein concerned in AChR aggregation. Bulbar weakness is typically predominant in this form of MG, and females are more often affected. The Lambert-Eaton Myasthenic Syndrome (LEMS) can occur in a paraneoplastic form (P-LEMS) usually with small cell lung cancer, or in a non-paraneoplastic form (NP-LEMS). In both, IgG antibodies to nerve terminal voltage-gated calcium channels (VGCCs), detectable in over 90% of patients, lead to VGCC loss and impaired quantal release of transmitter and may be implicated in the occasionally associated cerebellar ataxia. Neuromyotonia (NMT) and Cramp-Fasciculation syndrome (C-FS) are manifestations of peripheral nerve hyperexcitability and share some clinical and electromyographic features. Antibodies to voltage-gated potassium channels (VGKCs) are present in about 40% of NMT patients, but less frequently in C-FS, and appear to cause loss of functional VGKCs. They may also be implicated in the Maladie de Morvan and limbic encephalitis that can associate with NMT: The antibodies described here provide valuable aids to diagnosis and management. The Congenital Myasthenic Syndromes are a group of genetically determined heterogeneous disorders, usually recessively inherited. The commonest mutation sites appear to be the acetylcholine receptor epsilon-subunit and rapsyn.

  20. Single Fiber Electromyographic Jitter to Detect Acute Changes in Neuromuscular Function in Young and Adult Rats

    EPA Science Inventory

    Introduction: Exposure to irreversible cholinesterase (ChE)-inhibiting compounds, such as organophosphates may produce neuromuscular dysfunction. However, less is known about changes in neuromuscular transmission after treatment with reversible ChE-inhibitors. These studies adapt...

  1. The effect of centrophenoxine at the skeletal neuromuscular junction.

    PubMed

    Mistry, S D; Tripathi, C G; Bhavsar, V H; Kelkar, V V

    1985-01-01

    Centrophenoxine exhibited some interesting actions at the neuromuscular junction. The drug was ineffective in rat or chick preparations, but blocked neuromuscular transmission in frog preparations. The blockade was reversed by adrenaline, potassium, choline and physostigmine. The drug had no effect on muscle contractility or endplate cholinoceptor. Hemicholinium 3 induced a neuromuscular blockade in rat (in vivo) which was reversed by choline but not by centrophenoxine. Neither of these two drugs could reverse the blocking effect of hemicholinium in frog preparations. It is concluded that centrophenoxine acts only in frog and the blockade involves a presynaptic mechanism. The work further suggests that choline uptake systems in the rat and the frog may not be identical, since choline competed with hemicholinium for the uptake system in rat and with centrophenoxine (but not with hemicholinium) in the frog.

  2. Train-of-four fade during onset of neuromuscular block with nondepolarising neuromuscular blocking agents.

    PubMed

    Gibson, F M; Mirakhur, R K

    1989-04-01

    Fade in the train-of-four (TOF) responses during onset of neuromuscular block was studied following administration of atracurium (225 or 450 micrograms/kg), vecuronium (40 or 80 micrograms/kg), pancuronium (60 or 120 micrograms/kg) and tubocurarine (450 micrograms/kg). TOF ratios were measured at approximate heights of T1 (first response in the TOF) of 75, 50 and 25%. Fade in TOF increased as the height of T1 decreased, with maximum fade being observed at T1 of 25%. The greatest difference between relaxants was observed at T1 of 25%, vecuronium showing the least fade and pancuronium, atracurium and tubocurarine showing increasing fade, in that order. The difference between atracurium and tubocurarine or between vecuronium and pancuronium was not significant, but the degree of TOF fade was significantly greater with atracurium and tubocurarine in comparison to vecuronium or pancuronium.

  3. Neuromuscular block after intra-arterially injected acetylcholine

    PubMed Central

    Pinelli, P.; Tonali, P.; Gambi, D.

    1973-01-01

    It has been suggested that the effect of ACTH in myasthenia gravis may be ascribed to an action involving neuromuscular transmission which favours repolarization processes, with a tendency towards hyperpolarization of the membranes of muscle fibres and motor nerve endings. A similar mechanism has been postulated for the action of ACTH in epilepsy (Klein, 1970). A direct or indirect action on nerve membrane would interfere with depolarization. There is evidence of raised concentration of intracellular potassium and increased outflow of sodium ions which would cause hyperpolarization of the membrane. This paper studies the effect of ACTH on the late block of neuromuscular transmission caused by acetylcholine (ACTH). Images PMID:4350704

  4. Neuromuscular hip biomechanics and pathology in the athlete.

    PubMed

    Torry, Michael R; Schenker, Mara L; Martin, Hal D; Hogoboom, Doug; Philippon, Marc J

    2006-04-01

    Although hip arthroscopic techniques have been developed and evolved over the last 5 to 10 years to help active athletes, the mechanisms of athletic hip injuries across various sports are not well understood. The purpose of this article is to review the literature related to the osseous and ligamentous support as well as the neuromuscular control strategies associated with hip joint mechanics. The neuromuscular contributions to hip stability and mobility with respect to gait will be provided because this data represents the largest body of knowledge regarding hip function. Further, this article will present and describe probable mechanisms of injury in sporting activities most often associated with hip injury in the young athlete.

  5. Inspiratory muscle training in the patient with neuromuscular disease.

    PubMed

    McCool, F D; Tzelepis, G E

    1995-11-01

    Pulmonary complications due to respiratory muscle dysfunction are commonly a source of morbidity and mortality in patients with neuromuscular diseases. This review discusses the adverse effects of respiratory muscle weakness on pulmonary mechanics and examines the role that inspiratory muscle training may play in reversing pulmonary dysfunction in these individuals. In asymptomatic persons, it is well established that the inspiratory muscles can be trained to increase both force and endurance. In patients with neuromuscular diseases, the effects of training protocols on force and endurance are more controversial. This article reviews seven studies that have evaluated respiratory muscle training in a total of 75 patients with varied neuromuscular disorders. Training regimens included breathing through inspiratory resistive loads and isocapnic hyperpnea. Despite methodologic differences among studies, investigators have generally shown that the inspiratory muscles are similar to other skeletal muscle groups in that they can be trained for both force and endurance in these patients. The training-related improvements in inspiratory muscle performance are more pronounced in patients who are less severely affected by their disease. In those patients who have disease to the extent that they are already retaining carbon dioxide, there is little change in force or endurance with training. In these individuals, the inspiratory muscles may already be working at a level sufficiently severe to provide a training stimulus with each breath. No adverse effects of inspiratory muscle training were reported. Inspiratory muscle training can improve force and endurance in patients with neuromuscular weakness.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7480122

  6. Neuromuscular junction integrity after chronic nerve compression injury.

    PubMed

    Mozaffar, Tahseen; Strandberg, Erika; Abe, Kazuko; Hilgenberg, Lutz G; Smith, Martin A; Gupta, Ranjan

    2009-01-01

    Chronic nerve compression injuries (CNC) are progressive demyelinating disorders characterized by a gradual decline of the nerve conduction velocity (NCV) in the affected nerve region. CNC injury induces a robust Schwann cell response with axonal sprouting, but without morphologic evidence of axonal injury. We hypothesize that early CNC injury occurs without damage to neuromuscular junction of motor axons. A well-established animal model was used to assess for damage to motor axons. As sprouting is considered a hallmark of regeneration during and after axonal degeneration and sprouting was confirmed visually at 2 weeks in CNC animals, we assessed for axonal degeneration in motor nerves after CNC by evaluating the integrity of the neuromuscular junction. NCV exhibited a gradual progressive decline consistent with the human condition. Compound motor action potential amplitudes decreased slightly immediately and plateaued, indicating that there was not sustained and increasing axonal loss. Sprouting was confirmed using immunofluorescence and by an increase in number of unmyelinated axons and Remak bundles. Blind analysis of the neuromuscular junction showed no difference between control and CNC images, indicating that there was no evidence for end-unit axonal loss in the soleus muscle. Because the progressive decline in NCV was not paired with a similar progressive decline in amplitude, it is likely that axonal loss is not responsible for slowing of action potentials. Blind analysis of the neuromuscular junction provides further evidence that the axonal sprouting seen early after CNC injury is not a consequence of axonal degeneration in the motor nerves. PMID:18655131

  7. Mainstreaming Children with a Neuromuscular Disease: A Map of Concerns.

    ERIC Educational Resources Information Center

    Strong, Kristine; Sandoval, Jonathan

    1999-01-01

    Four focus groups (n=21) were conducted to gather information about coping issues and teacher attitudes related to the education of children with a neuromuscular disease. Results indicate a need for better home/school communication, a need to establish children's sense of competence, and a need for improved peer relationships. (Author/CR)

  8. Drug Development and Challenges for Neuromuscular Clinical Trials.

    PubMed

    El Mouelhi, Mohamed

    2016-03-01

    Drug development process faces many challenges, including those encountered in clinical trials for neuromuscular diseases. Drug development is a lengthy and highly costly process. Out of 10 compounds entering first study in man (phase 1), only one compound reaches the market after an average of 14 years with a cost of $2.7 billion. Nevertheless, according to the Centers for Medicare and Medicaid services, prescription drugs constituted only 9 % of each health care dollar spent in USA in 2013. Examples of challenges encountered in neuromuscular clinical trials include lack of validated patient-reported outcome tools, blinding issues, and the use of placebo in addition to lack of health authority guidance for orphan diseases. Patient enrollment challenge is the leading cause of missed clinical trial deadlines observed in about 80 % of clinical trials, resulting in delayed availability of potentially life-saving therapies. Another specific challenge introduced by recent technology is the use of social media and risk of bias. Sharing personal experiences while in the study could easily introduce bias among patients that would interfere with accurate interpretation of collected data. To minimize this risk, recent neuromuscular studies incorporate as an inclusion criterion the patient's agreement not to share any of study experiences through social media with other patients during the study conduct. Consideration of these challenges will allow timely response to the high unmet medical needs for many neuromuscular diseases. PMID:26691331

  9. Assessment of Neuromuscular Function Using Percutaneous Electrical Nerve Stimulation.

    PubMed

    Rozand, Vianney; Grosprêtre, Sidney; Stapley, Paul J; Lepers, Romuald

    2015-09-13

    Percutaneous electrical nerve stimulation is a non-invasive method commonly used to evaluate neuromuscular function from brain to muscle (supra-spinal, spinal and peripheral levels). The present protocol describes how this method can be used to stimulate the posterior tibial nerve that activates plantar flexor muscles. Percutaneous electrical nerve stimulation consists of inducing an electrical stimulus to a motor nerve to evoke a muscular response. Direct (M-wave) and/or indirect (H-reflex) electrophysiological responses can be recorded at rest using surface electromyography. Mechanical (twitch torque) responses can be quantified with a force/torque ergometer. M-wave and twitch torque reflect neuromuscular transmission and excitation-contraction coupling, whereas H-reflex provides an index of spinal excitability. EMG activity and mechanical (superimposed twitch) responses can also be recorded during maximal voluntary contractions to evaluate voluntary activation level. Percutaneous nerve stimulation provides an assessment of neuromuscular function in humans, and is highly beneficial especially for studies evaluating neuromuscular plasticity following acute (fatigue) or chronic (training/detraining) exercise.

  10. Biochemistry of Neuromuscular Diseases: A Course for Undergraduate Students

    ERIC Educational Resources Information Center

    Ohlendieck, Kay

    2002-01-01

    This article outlines an undergraduate course focusing on supramolecular membrane protein complexes involved in the molecular pathogenesis of neuromuscular disorders. The emphasis of this course is to introduce students to the key elements involved in the ion regulation and membrane stabilization during muscle contraction and the role of these…

  11. Neuromuscular activation patterns during treadmill walking after space flight

    NASA Technical Reports Server (NTRS)

    Layne, C. S.; McDonald, P. V.; Bloomberg, J. J.

    1997-01-01

    Astronauts adopt a variety of neuromuscular control strategies during space flight that are appropriate for locomoting in that unique environment, but are less than optimal upon return to Earth. We report here the first systematic investigation of potential adaptations in neuromuscular activity patterns associated with postflight locomotion. Astronaut-subjects were tasked with walking on a treadmill at 6.4 km/h while fixating a visual target 30 cm away from their eyes after space flights of 8-15 days. Surface electromyography was collected from selected lower limb muscles and normalized with regard to mean amplitude and temporal relation to heel strike. In general, high correlations (more than 0.80) were found between preflight and postflight activation waveforms for each muscle and each subject: however relative activation amplitude around heel strike and toe off was changed as a result of flight. The level of muscle cocontraction and activation variability, and the relationship between the phasic characteristics of the ankle musculature in preparation for toe off also were altered by space flight. Subjects also reported oscillopsia during treadmill walking after flight. These findings indicate that, after space flight, the sensory-motor system can generate neuromuscular-activation strategies that permit treadmill walking, but subtle changes in lower-limb neuromuscular activation are present that may contribute to increased lower limb kinematic variability and oscillopsia also present during postflight walking.

  12. Facial rehabilitation: a neuromuscular reeducation, patient-centered approach.

    PubMed

    Vanswearingen, Jessie

    2008-05-01

    Individuals with facial paralysis and distorted facial expressions and movements secondary to a facial neuromotor disorder experience substantial physical, psychological, and social disability. Previously, facial rehabilitation has not been widely available or considered to be of much benefit. An emerging rehabilitation science of neuromuscular reeducation and evidence for the efficacy of facial neuromuscular reeducation, a process of facilitating the return of intended facial movement patterns and eliminating unwanted patterns of facial movement and expression, may provide patients with disorders of facial paralysis or facial movement control opportunity for the recovery of facial movement and function. We provide a brief overview of the scientific rationale for facial neuromuscular reeducation in the structure and function of the facial neuromotor system, the neuropsychology of facial expression, and relations among expressions, movement, and emotion. The primary purpose is to describe principles of neuromuscular reeducation, assessment and outcome measures, approach to treatment, the process, including surface-electromyographic biofeedback as an adjunct to reeducation, and the goal of enhancing the recovery of facial expression and function in a patient-centered approach to facial rehabilitation.

  13. Neuromuscular exercise as treatment of degenerative knee disease.

    PubMed

    Ageberg, Eva; Roos, Ewa M

    2015-01-01

    Exercise is recommended as first-line treatment of degenerative knee disease. Our hypothesis is that neuromuscular exercise is feasible and at least as effective as traditionally used strength or aerobic training but aims to target more closely the sensorimotor deficiencies and functional instability associated with the degenerative knee disease than traditionally used training methods.

  14. Endomicroscopy and electromyography of neuromuscular junctions in situ

    PubMed Central

    Brown, Rosalind; Dissanayake, Kosala N; Skehel, Paul A; Ribchester, Richard R

    2014-01-01

    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: WldS mice, which coexpress the Wallerian-degeneration Slow (WldS) 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. PMID:25540801

  15. Neuromuscular Activity of Micrurus laticollaris (Squamata: Elapidae) Venom in Vitro

    PubMed Central

    Carbajal-Saucedo, Alejandro; Floriano, Rafael Stuani; Dal Belo, Cháriston André; Olvera-Rodríguez, Alejandro; Alagón, Alejandro; Rodrigues-Simioni, Léa

    2014-01-01

    In this work, we have examined the neuromuscular activity of Micrurus laticollaris (Mexican coral snake) venom (MLV) in vertebrate isolated nerve-muscle preparations. In chick biventer cervicis preparations, the MLV induced an irreversible concentration- and time-dependent (1–30 µg/mL) neuromuscular blockade, with 50% blockade occurring between 8 and 30 min. Muscle contractures evoked by exogenous acetylcholine were completely abolished by MLV, whereas those of KCl were also significantly altered (86% ± 11%, 53% ± 11%, 89% ± 5% and 89% ± 7% for one, three, 10 and 30 µg of venom/mL, respectively; n = 4; p < 0.05). In mouse phrenic nerve-diaphragm preparations, MLV (1–10 µg/mL) promoted a slight increase in the amplitude of twitch-tension (3 µg/mL), followed by neuromuscular blockade (n = 4); the highest concentration caused complete inhibition of the twitches (time for 50% blockade = 26 ± 3 min), without exhibiting a previous neuromuscular facilitation. The venom (3 µg/mL) induced a biphasic modulation in the frequency of miniature end-plate potentials (MEPPs)/min, causing a significant increase after 15 min, followed by a decrease after 60 min (from 17 ± 1.4 (basal) to 28 ± 2.5 (t15) and 12 ± 2 (t60)). The membrane resting potential of mouse diaphragm preparations pre-exposed or not to d-tubocurarine (5 µg/mL) was also significantly less negative with MLV (10 µg/mL). Together, these results indicate that M. laticollaris venom induces neuromuscular blockade by a combination of pre- and post-synaptic activities. PMID:24445448

  16. Neuromuscular activity of Micrurus laticollaris (Squamata: Elapidae) venom in vitro.

    PubMed

    Carbajal-Saucedo, Alejandro; Floriano, Rafael Stuani; Dal Belo, Cháriston André; Olvera-Rodríguez, Alejandro; Alagón, Alejandro; Rodrigues-Simioni, Léa

    2014-01-17

    In this work, we have examined the neuromuscular activity of Micrurus laticollaris (Mexican coral snake) venom (MLV) in vertebrate isolated nerve-muscle preparations. In chick biventer cervicis preparations, the MLV induced an irreversible concentration- and time-dependent (1-30 µg/mL) neuromuscular blockade, with 50% blockade occurring between 8 and 30 min. Muscle contractures evoked by exogenous acetylcholine were completely abolished by MLV, whereas those of KCl were also significantly altered (86% ± 11%, 53% ± 11%, 89% ± 5% and 89% ± 7% for one, three, 10 and 30 µg of venom/mL, respectively; n = 4; p < 0.05). In mouse phrenic nerve-diaphragm preparations, MLV (1-10 µg/mL) promoted a slight increase in the amplitude of twitch-tension (3 µg/mL), followed by neuromuscular blockade (n = 4); the highest concentration caused complete inhibition of the twitches (time for 50% blockade = 26 ± 3 min), without exhibiting a previous neuromuscular facilitation. The venom (3 µg/mL) induced a biphasic modulation in the frequency of miniature end-plate potentials (MEPPs)/min, causing a significant increase after 15 min, followed by a decrease after 60 min (from 17 ± 1.4 (basal) to 28 ± 2.5 (t15) and 12 ± 2 (t60)). The membrane resting potential of mouse diaphragm preparations pre-exposed or not to d-tubocurarine (5 µg/mL) was also significantly less negative with MLV (10 µg/mL). Together, these results indicate that M. laticollaris venom induces neuromuscular blockade by a combination of pre- and post-synaptic activities.

  17. The Onecut Transcription Factor HNF-6 Regulates in Motor Neurons the Formation of the Neuromuscular Junctions

    PubMed Central

    Audouard, Emilie; Schakman, Olivier; René, Frédérique; Huettl, Rosa-Eva; Huber, Andrea B.; Loeffler, Jean-Philippe; Gailly, Philippe; Clotman, Frédéric

    2012-01-01

    The neuromuscular junctions are the specialized synapses whereby spinal motor neurons control the contraction of skeletal muscles. The formation of the neuromuscular junctions is controlled by a complex interplay of multiple mechanisms coordinately activated in motor nerve terminals and in their target myotubes. However, the transcriptional regulators that control in motor neurons the genetic programs involved in neuromuscular junction development remain unknown. Here, we provide evidence that the Onecut transcription factor HNF-6 regulates in motor neurons the formation of the neuromuscular junctions. Indeed, adult Hnf6 mutant mice exhibit hindlimb muscle weakness and abnormal locomotion. This results from defects of hindlimb neuromuscular junctions characterized by an abnormal morphology and defective localization of the synaptic vesicle protein synaptophysin at the motor nerve terminals. These defects are consequences of altered and delayed formation of the neuromuscular junctions in newborn mutant animals. Furthermore, we show that the expression level of numerous regulators of neuromuscular junction formation, namely agrin, neuregulin-2 and TGF-ß receptor II, is downregulated in the spinal motor neurons of Hnf6 mutant newborn animals. Finally, altered formation of neuromuscular junction-like structures in a co-culture model of wildtype myotubes with mutant embryonic spinal cord slices is rescued by recombinant agrin and neuregulin, indicating that depletion in these factors contributes to defective neuromuscular junction development in the absence of HNF-6. Thus, HNF-6 controls in spinal motor neurons a genetic program that coordinates the formation of hindlimb neuromuscular junctions. PMID:23227180

  18. Las Vegas

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image of Las Vegas, NV was acquired on August, 2000 and covers an area 42 km (25 miles) wide and 30 km (18 miles) long. The image displays three bands of the reflected visible and infrared wavelength region, with a spatial resolution of 15 m. McCarran International Airport to the south and Nellis Air Force Base to the NE are the two major airports visible. Golf courses appear as bright red areas of worms. The first settlement in Las Vegas (which is Spanish for The Meadows) was recorded back in the early 1850s when the Mormon church, headed by Brigham Young, sent a mission of 30 men to construct a fort and teach agriculture to the Indians. Las Vegas became a city in 1905 when the railroad announced this city was to be a major division point. Prior to legalized gambling in 1931, Las Vegas was developing as an agricultural area. Las Vegas' fame as a resort area became prominent after World War II. The image is located at 36.1 degrees north latitude and 115.1 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  19. [Neuromuscular disease: respiratory clinical assessment and follow-up].

    PubMed

    Martínez Carrasco, C; Villa Asensi, J R; Luna Paredes, M C; Osona Rodríguez de Torres, F B; Peña Zarza, J A; Larramona Carrera, H; Costa Colomer, J

    2014-10-01

    Patients with neuromuscular disease are an important group at risk of frequently suffering acute or chronic respiratory failure, which is their main cause of death. They require follow-up by a pediatric respiratory medicine specialist from birth or diagnosis in order to confirm the diagnosis and treat any respiratory complications within a multidisciplinary context. The ventilatory support and the cough assistance have improved the quality of life and long-term survival for many of these patients. In this paper, the authors review the pathophysiology, respiratory function evaluation, sleep disorders, and the most frequent respiratory complications in neuromuscular diseases. The various treatments used, from a respiratory medicine point of view, will be analyzed in a next paper.

  20. The ageing neuromuscular system and sarcopenia: a mitochondrial perspective

    PubMed Central

    Picard, Martin; Turnbull, Doug M.

    2016-01-01

    Abstract Skeletal muscles undergo structural and functional decline with ageing, culminating in sarcopenia. The underlying neuromuscular mechanisms have been the subject of intense investigation, revealing mitochondrial abnormalities as potential culprits within both nerve and muscle cells. Implicated mechanisms involve impaired mitochondrial dynamics, reduced organelle biogenesis and quality control via mitophagy, accumulation of mitochondrial DNA (mtDNA) damage and respiratory chain defect, metabolic disturbance, pro‐apoptotic signalling, and oxidative stress. This article provides an overview of the cellular mechanisms whereby mitochondria may promote maladaptive changes within motor neurons, the neuromuscular junction (NMJ) and muscle fibres. Lifelong physical activity, which promotes mitochondrial health across tissues, is emerging as an effective countermeasure for sarcopenia. PMID:26921061

  1. An overview of neurological and neuromuscular signs in mitochondrial diseases.

    PubMed

    Chaussenot, A; Paquis-Flucklinger, V

    2014-05-01

    Mitochondrial disorders have a broad clinical spectrum and are genetically heterogeneous, involving two genomes. These disorders may be develop at any age, with isolated or multiple system involvement, and any pattern of inheritance. Neurological involvement is the most frequent, and concerns muscular, peripheral and central nervous system. Among these diverse signs, some are suggestive of mitochondrial disease, such as progressive external ophthalmoplegia, exercise intolerance, psychomotor regression, stroke-like episodes, refractory epilepsy and Epilepsia Partialis Continua. Others are less specific and mitochondrial hypothesis may be evocated because of either association of different neuromuscular signs or a multisystemic involvement. This review describes the wealth of this neurological and neuromuscular symptomatology through different syndromes reported in the literature, according to preponderant signs and to modes of inheritance, as key elements to guide genetics testing.

  2. The role of neuromuscular inhibition in hamstring strain injury recurrence.

    PubMed

    Fyfe, Jackson J; Opar, David A; Williams, Morgan D; Shield, Anthony J

    2013-06-01

    Hamstring strain injuries are amongst the most common and problematic injuries in a wide range of sports that involve high speed running. The comparatively high rate of hamstring injury recurrence is arguably the most concerning aspect of these injuries. A number of modifiable and nonmodifiable risk factors are proposed to predispose athletes to hamstring strains. Potentially, the persistence of risk factors and the development of maladaptations following injury may explain injury recurrence. Here, the role of neuromuscular inhibition following injury is discussed as a potential mechanism for several maladaptations associated with hamstring re-injury. These maladaptations include eccentric hamstring weakness, selective hamstring atrophy and shifts in the knee flexor torque-joint angle relationship. Current evidence indicates that athletes return to competition after hamstring injury having developed maladaptations that predispose them to further injury. When rehabilitating athletes to return to competition following hamstring strain injury, the role of neuromuscular inhibition in re-injury should be considered.

  3. Neuromuscular deficits after peripheral joint injury: a neurophysiological hypothesis.

    PubMed

    Ward, Sarah; Pearce, Alan J; Pietrosimone, Brian; Bennell, Kim; Clark, Ross; Bryant, Adam L

    2015-03-01

    In addition to biomechanical disturbances, peripheral joint injuries (PJIs) can also result in chronic neuromuscular alterations due in part to loss of mechanoreceptor-mediated afferent feedback. An emerging perspective is that PJI should be viewed as a neurophysiological dysfunction, not simply a local injury. Neurophysiological and neuroimaging studies have provided some evidence for central nervous system (CNS) reorganization at both the cortical and spinal levels after PJI. The novel hypothesis proposed is that CNS reorganization is the underlying mechanism for persisting neuromuscular deficits after injury, particularly muscle weakness. There is a lack of direct evidence to support this hypothesis, but future studies utilizing force-matching tasks with superimposed transcranial magnetic stimulation may be help clarify this notion.

  4. [Neuromuscular disease: respiratory clinical assessment and follow-up].

    PubMed

    Martínez Carrasco, C; Villa Asensi, J R; Luna Paredes, M C; Osona Rodríguez de Torres, F B; Peña Zarza, J A; Larramona Carrera, H; Costa Colomer, J

    2014-10-01

    Patients with neuromuscular disease are an important group at risk of frequently suffering acute or chronic respiratory failure, which is their main cause of death. They require follow-up by a pediatric respiratory medicine specialist from birth or diagnosis in order to confirm the diagnosis and treat any respiratory complications within a multidisciplinary context. The ventilatory support and the cough assistance have improved the quality of life and long-term survival for many of these patients. In this paper, the authors review the pathophysiology, respiratory function evaluation, sleep disorders, and the most frequent respiratory complications in neuromuscular diseases. The various treatments used, from a respiratory medicine point of view, will be analyzed in a next paper. PMID:24709048

  5. Aggravated neuromuscular symptoms of mercury exposure from dental amalgam fillings.

    PubMed

    Akbal, Ayla; Yılmaz, Hınç; Tutkun, Engin; Köş, Durdu Mehmet

    2014-01-01

    Dental amalgam fillings are widely used all over the world. However, their mercury content can lead to various side effects and clinical problems. Acute or chronic mercury exposure can cause several side effects on the central nerve system, renal and hepatic functions, immune system, fetal development and it can play a role on exacerbation of neuromuscular diseases. In this case, we will present a patient with vacuolar myopathy whose symptoms were started and aggravated with her dental amalgam fillings.

  6. Report on Adaptive Force, A Specific Neuromuscular Function.

    PubMed

    Hoff, Marko; Schaefer, Laura; Heinke, Nancy; Bittmann, Frank

    2015-09-11

    In real life motions, as well as in sports, the adaptation of the neuromuscular systems to externally applied forces plays an important role. The term Adaptive Force (AF) shall characterize the ability of the nerve-muscle-system to adapt to impacting external forces during isometric and eccentric muscle action. The focus in this paper is on the concept of this neuromuscular action, which is not yet described in this way. A measuring system was constructed and evaluated for this specific neuromuscular function, but only the main information of the evaluation of the measuring system and the preliminary reference values are mentioned here, while an article with detailed description will be published separately. This paper concentrates on the three following points: 1) What is the peculiarity of this neuromuscular function, introduced as AF? 2) Is the measuring system able to capture its specific characteristics and which phases of measurement occur? 3) It seems reasonable to discuss if AF can be distinguished and classified among the known force concepts. The article describes the measuring system and how it is able to capture special features of real life motions like submaximal intensities and the subjects' option to react adequately on external varying forces. Furthermore, within one measurement the system records three different force qualities: the isometric submaximal Adaptive Force (AFiso), the maximal isometric Adaptive Force (AFisomax) and the maximal eccentric Adaptive Force (AFeccmax). Each of these phases provide different and unique information on the nerve-muscle-system that are discussed in detail. Important, in terms of the Adaptive Force, seems to be the combination of conditional and coordinative abilities. This project was funded by the Federal Ministry of Economy and Technology (Project ZIM KF2262301FO9). PMID:26913155

  7. An Overview of Cardiac Management in Neuromuscular Disease.

    PubMed

    Hickey, Renee M; Cullen, John D; Sachs, George M

    2016-01-01

    Muscular dystrophy and myasthenia gravis are two neuromuscular disorders that can involve significant cardiovascular complications. The frequency and severity of cardiac pathology varies widely among the muscular dystrophies. In some, it is nearly inevitable and requires regular evaluation. In others, assessment of cardiac function can be more symptom-driven. On-ly a minority of myasthenic patients manifest disease-related cardiovascular complications; however, their presentation can be rapidly progressive and life-threatening.. PMID:27347224

  8. An Overview of Cardiac Management in Neuromuscular Disease

    PubMed Central

    Hickey, Renee M.; Cullen, John D.; Sachs, George M.

    2016-01-01

    Muscular dystrophy and myasthenia gravis are two neuromuscular disorders that can involve significant cardiovascular complications. The frequency and severity of cardiac pathology varies widely among the muscular dystrophies. In some, it is nearly inevitable and requires regular evaluation. In others, assessment of cardiac function can be more symptom-driven. On-ly a minority of myasthenic patients manifest disease-related cardiovascular complications; however, their presentation can be rapidly progressive and life-threatening.. PMID:27347224

  9. Neuromuscular electric stimulation in patellofemoral dysfunction: literature review

    PubMed Central

    dos Santos, Ricardo Lucas; Souza, Márcia Leal São Pedro; dos Santos, Fernanda Andrade

    2013-01-01

    Patellofemoral dysfunction is a fairly common deficiency among young individuals that primarily affects females and may be characterized by pain, swelling and retropatellar crepitation. The purpose of this review of literature from the period between 2005 and 2011 was to systematize knowledge in relation to the increase in quadriceps muscle strength and pain relief in patients with patellofemoral dysfunction, using neuromuscular electrical stimulation and resistance exercises. The inclusion criteria were intervention articles from the past six years, in English, Spanish and Portuguese, which used muscle strengthening and neuromuscular electrical stimulation for rehabilitation obtained through searches in the electronic databases Medline and Lilacs and in the Bireme library. The bibliographic search yielded 28 references, of which nine were excluded in accordance with the aims and inclusion criteria while 16 articles were selected for reading of the abstracts and subsequent analysis. Mediumfrequency Neuromuscular Electrical Stimulation (NMES) can be used in association with resistance exercises as an adjuvant in the treatment of patellofemoral dysfunction (PFD), both to achieve muscle rebalance and for pain relief. PMID:24453645

  10. A biodynamic feedthrough model based on neuromuscular principles.

    PubMed

    Venrooij, Joost; Abbink, David A; Mulder, Mark; van Paassen, Marinus M; Mulder, Max; van der Helm, Frans C T; Bulthoff, Heinrich H

    2014-07-01

    A biodynamic feedthrough (BDFT) model is proposed that describes how vehicle accelerations feed through the human body, causing involuntary limb motions and so involuntary control inputs. BDFT dynamics strongly depend on limb dynamics, which can vary between persons (between-subject variability), but also within one person over time, e.g., due to the control task performed (within-subject variability). The proposed BDFT model is based on physical neuromuscular principles and is derived from an established admittance model-describing limb dynamics-which was extended to include control device dynamics and account for acceleration effects. The resulting BDFT model serves primarily the purpose of increasing the understanding of the relationship between neuromuscular admittance and biodynamic feedthrough. An added advantage of the proposed model is that its parameters can be estimated using a two-stage approach, making the parameter estimation more robust, as the procedure is largely based on the well documented procedure required for the admittance model. To estimate the parameter values of the BDFT model, data are used from an experiment in which both neuromuscular admittance and biodynamic feedthrough are measured. The quality of the BDFT model is evaluated in the frequency and time domain. Results provide strong evidence that the BDFT model and the proposed method of parameter estimation put forward in this paper allows for accurate BDFT modeling across different subjects (accounting for between-subject variability) and across control tasks (accounting for within-subject variability).

  11. Neuromuscular signs associated with acute hypophosphatemia in a dog.

    PubMed

    Claus, Kimberly N; Day, Thomas K; Wolf, Christina

    2015-01-01

    The purpose of this report was to describe the successful recognition and management of neuromuscular dysfunction secondary to severe, acute hypophosphatemia in an adult dog with a 2 day history of vomiting, anorexia, and abdominal pain. Radiographs were suggestive of a foreign body obstruction, and surgery was recommended. Resection and anastomosis of the distal duodenum and proximal jejunum was performed. The dog recovered uneventfully, but approximately 36 hr postoperatively, he was found to have significant weakness and muscle tremors that were accompanied by hyperthermia. The only significant abnormality on a serum biochemical profile was a phosphorous level of 0.26 mmol/L. Within 6 hr of initiating phosphorous supplementation, the patient fully recovered and had no residual signs of neuromuscular dysfunction. Signs of neurologic dysfunction secondary to hypophosphatemia are commonly recognized in human patients. Reports of patients with severe muscle weakness, some of which necessitate ventilation due to weakening of muscles of respiration, are common throughout the literature. Less commonly, tremors are noted. This is the first known report of neuromuscular signs recognized and rapidly corrected in a dog. Although it is likely to be uncommon, hypophosphatemia should be recognized as a differential diagnosis in patients with tremors and/or muscle weakness. PMID:25955140

  12. Altered neuromuscular control mechanisms of the trapezius muscle in fibromyalgia

    PubMed Central

    2010-01-01

    Background fibromyalgia is a relatively common condition with widespread pain and pressure allodynia, but unknown aetiology. For decades, the association between motor control strategies and chronic pain has been a topic for debate. One long held functional neuromuscular control mechanism is differential activation between regions within a single muscle. The aim of this study was to investigate differences in neuromuscular control, i.e. differential activation, between myalgic trapezius in fibromyalgia patients and healthy controls. Methods 27 fibromyalgia patients and 30 healthy controls performed 3 minutes bilateral shoulder elevations with different loads (0-4 Kg) with a high-density surface electromyographical (EMG) grid placed above the upper trapezius. Differential activation was quantified by the power spectral median frequency of the difference in EMG amplitude between the cranial and caudal parts of the upper trapezius. The average duration of the differential activation was described by the inverse of the median frequency of the differential activations. Results the median frequency of the differential activations was significantly lower, and the average duration of the differential activations significantly longer in fibromyalgia compared with controls at the two lowest load levels (0-1 Kg) (p < 0.04), but not at the two highest load levels (2 and 4 Kg). Conclusion these findings illustrate a different neuromuscular control between fibromyalgia patients and healthy controls during a low load functional task, either sustaining or resulting from the chronic painful condition. The findings may have clinical relevance for rehabilitation strategies for fibromyalgia. PMID:20205731

  13. Neuromuscular interactions around the knee in children, adults and elderly

    PubMed Central

    Kellis, Eleftherios; Mademli, Lida; Patikas, Dimitrios; Kofotolis, Nikolaos

    2014-01-01

    Although injury and neuromuscular activation patterns may be common for all individuals, there are certain factors which differentiate neuromuscular activity responses between children, adults and elderly. The purpose of this study is to review recent evidence on age differences in neural activation and muscle balances around the knee when performing single joint movements. Particularly, current evidence indicates that there are some interesting similarities in the neuromuscular mechanisms by which children or the elderly differ compared with adults. Both children and elderly display a lower absolute muscle strength capacity than adults which cannot fully be explained by differences in muscle mass. Quadriceps activation failure is a common symptom of all knee injuries, irrespective of age but it is likely that its effect is more evident in children or adults. While one might expect that antagonist co-activation would differ between age categories, it appears that this is not the case. Although hamstring: quadriceps ratio levels are altered after knee injury, it is not clear whether this is an age specific response. Finally, evidence suggests that both children and the elderly display less stiffness of the quadriceps muscle-tendon unit than adults which affects their knee joint function. PMID:25232523

  14. Neuromuscular signs associated with acute hypophosphatemia in a dog.

    PubMed

    Claus, Kimberly N; Day, Thomas K; Wolf, Christina

    2015-01-01

    The purpose of this report was to describe the successful recognition and management of neuromuscular dysfunction secondary to severe, acute hypophosphatemia in an adult dog with a 2 day history of vomiting, anorexia, and abdominal pain. Radiographs were suggestive of a foreign body obstruction, and surgery was recommended. Resection and anastomosis of the distal duodenum and proximal jejunum was performed. The dog recovered uneventfully, but approximately 36 hr postoperatively, he was found to have significant weakness and muscle tremors that were accompanied by hyperthermia. The only significant abnormality on a serum biochemical profile was a phosphorous level of 0.26 mmol/L. Within 6 hr of initiating phosphorous supplementation, the patient fully recovered and had no residual signs of neuromuscular dysfunction. Signs of neurologic dysfunction secondary to hypophosphatemia are commonly recognized in human patients. Reports of patients with severe muscle weakness, some of which necessitate ventilation due to weakening of muscles of respiration, are common throughout the literature. Less commonly, tremors are noted. This is the first known report of neuromuscular signs recognized and rapidly corrected in a dog. Although it is likely to be uncommon, hypophosphatemia should be recognized as a differential diagnosis in patients with tremors and/or muscle weakness.

  15. Methods for Multiloop Identification of Visual and Neuromuscular Pilot Responses.

    PubMed

    Olivari, Mario; Nieuwenhuizen, Frank M; Venrooij, Joost; Bülthoff, Heinrich H; Pollini, Lorenzo

    2015-12-01

    In this paper, identification methods are proposed to estimate the neuromuscular and visual responses of a multiloop pilot model. A conventional and widely used technique for simultaneous identification of the neuromuscular and visual systems makes use of cross-spectral density estimates. This paper shows that this technique requires a specific noninterference hypothesis, often implicitly assumed, that may be difficult to meet during actual experimental designs. A mathematical justification of the necessity of the noninterference hypothesis is given. Furthermore, two methods are proposed that do not have the same limitations. The first method is based on autoregressive models with exogenous inputs, whereas the second one combines cross-spectral estimators with interpolation in the frequency domain. The two identification methods are validated by offline simulations and contrasted to the classic method. The results reveal that the classic method fails when the noninterference hypothesis is not fulfilled; on the contrary, the two proposed techniques give reliable estimates. Finally, the three identification methods are applied to experimental data from a closed-loop control task with pilots. The two proposed techniques give comparable estimates, different from those obtained by the classic method. The differences match those found with the simulations. Thus, the two identification methods provide a good alternative to the classic method and make it possible to simultaneously estimate human's neuromuscular and visual responses in cases where the classic method fails.

  16. Fatty replacement of lower paraspinal muscles: normal and neuromuscular disorders

    SciTech Connect

    Hader, H.; Gadoth, N.; Heifetz, H.

    1983-11-01

    The physiologic replacement of the lower paraspinal muscles by fat was evaluated in 157 patients undergoing computed tomography for reasons unrelated to abnormalities of the locomotor system. Five patients with neuromuscular disorders were similarly evaluated. The changes were graded according to severity at three spinal levels: lower thoracic-upper lumbar, midlumbar, and lumbosacral. The results were analyzed in relation to age and gender. It was found that fatty replacement of paraspinal muscles is a normal age-progressive phenomenon most prominent in females. It progresses down the spine, being most advanced in the lumbosacral region. The severest changes in the five patients with neuromuscular disorders (three with poliomyelitis and two with progressive muscular dystrophy) consisted of complete muscle group replacement by fat. In postpoliomyelitis atrophy, the distribution was typically asymmetric and sometimes lacked clinical correlation. In muscular dystrophy, fatty replacement was symmetric, showing relative sparing of the psoas and multifidus muscles. In patients with neuromuscular diseases, computed tomography of muscles may be helpful in planning a better rehabilitation regimen.

  17. [Molecular mechanisms underlying the formation of neuromuscular junction].

    PubMed

    Higuchi, Osamu; Yamanashi, Yuji

    2011-07-01

    The neuromuscular junction (NMJ) is a synapse between a motor neuron and skeletal muscle. The contraction of skeletal muscle is controlled by the neurotransmitter acetylcholine (ACh), which is released from the motor nerve terminal. To achieve efficient neuromuscular transmission, acetylcholine receptors (AChRs) must be densely clustered on the muscle membrane of the NMJ. Failure of AChR clustering is associated with disorders of neuromuscular transmission such as congenital myasthenic syndromes (CMS) and myasthenia gravis (MG). Motoneuronal agrin and muscle-specific receptor tyrosine kinase (MuSK) are known to play essential roles in the formation and maintenance of NMJs in the central region of each muscle. However, it had been unclear how agrin activates MuSK. Recent studies have elucidated the roles of several key molecules, including the cytoplasmic adaptor protein Dok-7 and LDL receptor-related protein 4 (Lrp4), in agrin-induced MuSK activation. Moreover, new evidence indicates that cyclin-dependent kinase 5 (Cdk5) regulates postsynaptic differentiation. In this review, we summarize the latest developments in molecular mechanisms underlying NMJ formation in vertebrates. PMID:21747134

  18. Age-associated alterations of the neuromuscular junction.

    PubMed

    Jang, Youngmok C; Van Remmen, Holly

    2011-01-01

    Age-related loss of muscle mass and function greatly affects quality of life in the elderly population. Several hypotheses have been proposed but accumulating evidence point to alterations in neuromuscular system during aging as a key event that leads to functional denervation, muscle wasting, and weakness. Over the past few decades, age-associated degeneration of the neuromuscular junction (NMJ) and its components have been well documented. With advancing age, pre-terminal portions of motor axons exhibit regions of abnormal thinning, distension, and sprouting whereas postsynaptic endplates decrease in size and reduce in number, length, and density of postsynaptic folds. Although the exact underlying mechanisms are still lacking, recent studies provided direct evidence that age-associated increase in oxidative stress plays a crucial role in NMJ degeneration and progression of sarcopenia. Homozygous deletion of an important antioxidant enzyme, Cu,Zn superoxide dismutase (CuZnSOD, SOD1) leads to acceleration of age-dependent muscle atrophy, with a significant NMJ degeneration similar to that seen in old wild-type sarcopenic animals. In this short review, we briefly summarize the current understanding of some of the cellular and molecular changes in the NMJ during aging and suggest a role for oxidative stress and mitochondrial dysfunction in age-related changes in the maintenance of neuromuscular innervation.

  19. Guidelines for ethical behavior relating to clinical practice issues in neuromuscular and electrodiagnostic medicine.

    PubMed

    Abel, Naomi A; De Sousa, Eduardo A; Govindarajan, Raghav; Mayer, Matthew P; Simpson, David A

    2015-12-01

    The American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) developed guidelines to formalize the ethical standards that neuromuscular and electrodiagnostic (EDx) physicians should observe in their clinical and scientific activities. Neuromuscular and EDx medicine is a subspecialty of medicine that focuses on evaluation, diagnosis, and comprehensive medical management, including rehabilitation of individuals with neuromuscular disorders. Physicians working in this subspecialty focus on disorders of the motor unit, including muscle, neuromuscular junction, axon, plexus, nerve root, anterior horn cell, and the peripheral nerves (motor and sensory). The neuromuscular and EDx physician's goal is to diagnose and treat these conditions to mitigate their impact and improve the patient's quality of life. The guidelines are consistent with the Principles of Medical Ethics adopted by the American Medical Association and represent a revision of previous AANEM guidelines.

  20. Continuous neuromuscular blockade is associated with decreased mortality in post-cardiac arrest patients

    PubMed Central

    Salciccioli, Justin D.; Cocchi, Michael N.; Rittenberger, Jon C.; Peberdy, Mary Ann; Ornato, Joseph P.; Abella, Benjamin S.; Gaieski, David F.; Clore, John; Gautam, Shiva; Giberson, Tyler; Callaway, Clifton W.; Donnino, Michael W.

    2013-01-01

    Aim Neuromuscular blockade may improve outcome in patients with acute respiratory distress syndrome. In post-cardiac arrest patients receiving therapeutic hypothermia, neuromuscular blockade is often used to prevent shivering. Our objective was to determine whether neuromuscular blockade is associated with improved outcomes after out-of-hospital cardiac arrest. Methods A post-hoc analysis of a prospective observational study of comatose adult (> 18 years) out-of-hospital cardiac arrest at 4 tertiary cardiac arrest centers. The primary exposure of interest was neuromuscular blockade for 24 hours following return of spontaneous circulation and primary outcomes were in-hospital survival and neurologically intact survival. Secondary outcomes were evolution of oxygenation (PaO2:FiO2), and change in lactate. We tested the primary outcomes of in-hospital survival and neurologically intact survival with multivariable logistic regression. Secondary outcomes were tested with multivariable linear mixed-models. Results A total of 111 patients were analyzed. In patients with 24 hours of sustained neuromuscular blockade, the crude survival rate was 14/18 (78%) compared to 38/93 (41%) in patients without sustained neuromuscular blockade (p = 0.004). After multivariable adjustment, neuromuscular blockade was associated with survival (adjusted OR: 7.23, 95% CI: 1.56 –33.38). There was a trend toward improved functional outcome with neuromuscular blockade (50% vs. 28%; p = 0.07). Sustained neuromuscular blockade was associated with improved lactate clearance (adjusted p = 0.01). Conclusions We found that early neuromuscular blockade for a 24-hour period is associated with an increased probability of survival. Secondarily, we found that early, sustained neuromuscular blockade is associated with improved lactate clearance. PMID:23796602

  1. Use of Single Fiber Electromyographic Jitter to Detect Acute Changes in Neuromuscular Function in Young and Adult Rats

    EPA Science Inventory

    INTRODUCTION: Exposure to irreversible cholinesterase (ChE)-inhibiting compounds, such as organophosphates may produce neuromuscular dysfunction. However, less is known about changes in neuromuscular transmission after treatment with reversible ChE-inhibitors. These studies adapt...

  2. Neuromuscular responses to simulated brazilian jiu-jitsu fights.

    PubMed

    da Silva, Bruno Victor Corrêa; Ide, Bernardo Neme; de Moura Simim, Mário Antônio; Marocolo, Moacir; da Mota, Gustavo Ribeiro

    2014-12-01

    The aim of this study was to investigate the neuromuscular performance responses following successive Brazilian Jiu-Jitsu (BJJ) fights. Twenty-three BJJ athletes (age: 26.3 ± 6.3 years; body mass: 79.4 ± 9.7 kg; body height: 1.80 ± 0.1 m) undertook 3 simulated BJJ fights (10 min duration each separated by 15 min of rest). Neuromuscular performance was measured by the bench press throw (BPT) and vertical counter movement jump (VCMJ) tests, assessed before the 1st fight (Pre) and after the last one (Post). Blood lactate (LA) was measured at Pre, 1 min Post, and 15 min Post fights. Paired t-tests were employed in order to compare the BPT and VCMJ results. One-way ANOVA with Bonferroni post hoc tests were utilized to compare LA responses. The results revealed a significant (p < 0.05) increase in VCMJ performance (40.8 ± 5.5 cm Pre vs. 42.0 ± 5.8 cm Post), but no significant changes in the BPT (814 ± 167 W Pre vs. 835 ± 213 W Post) were observed. LA concentration increased significantly (p < 0.05) at Post, both in the 1st min (10.4 ± 2.7 mmol L-1) and the 15th min (6.4 ± 2.5 mmol L-1) of recovery. We concluded that successive simulated BJJ fights demanded considerable anaerobic contribution of ATP supply, reinforcing the high-intensity intermittent nature of the sport. Nevertheless, no negative impact on acute neuromuscular performance (power) was observed.

  3. Neuromuscular Responses to Simulated Brazilian Jiu-Jitsu Fights

    PubMed Central

    da Silva, Bruno Victor Corrêa; Ide, Bernardo Neme; de Moura Simim, Mário Antônio; Marocolo, Moacir; da Mota, Gustavo Ribeiro

    2014-01-01

    The aim of this study was to investigate the neuromuscular performance responses following successive Brazilian Jiu-Jitsu (BJJ) fights. Twenty-three BJJ athletes (age: 26.3 ± 6.3 years; body mass: 79.4 ± 9.7 kg; body height: 1.80 ± 0.1 m) undertook 3 simulated BJJ fights (10 min duration each separated by 15 min of rest). Neuromuscular performance was measured by the bench press throw (BPT) and vertical counter movement jump (VCMJ) tests, assessed before the 1st fight (Pre) and after the last one (Post). Blood lactate (LA) was measured at Pre, 1 min Post, and 15 min Post fights. Paired t-tests were employed in order to compare the BPT and VCMJ results. One-way ANOVA with Bonferroni post hoc tests were utilized to compare LA responses. The results revealed a significant (p < 0.05) increase in VCMJ performance (40.8 ± 5.5 cm Pre vs. 42.0 ± 5.8 cm Post), but no significant changes in the BPT (814 ± 167 W Pre vs. 835 ± 213 W Post) were observed. LA concentration increased significantly (p < 0.05) at Post, both in the 1st min (10.4 ± 2.7 mmol L-1) and the 15th min (6.4 ± 2.5 mmol L-1) of recovery. We concluded that successive simulated BJJ fights demanded considerable anaerobic contribution of ATP supply, reinforcing the high-intensity intermittent nature of the sport. Nevertheless, no negative impact on acute neuromuscular performance (power) was observed. PMID:25713685

  4. Rapid synthesis of acetylcholine receptors at neuromuscular junctions.

    PubMed

    Ramsay, D A; Drachman, D B; Pestronk, A

    1988-10-11

    The rate of acetylcholine receptor (AChR) degradation in mature, innervated mammalian neuromuscular junctions has recently been shown to be biphasic; up to 20% are rapidly turned over (RTOs; half life less than 1 day) whereas the remainder are lost more slowly ('stable' AChRs; half life 10-12 days). In order to maintain normal junctional receptor density, synthesis and insertion of AChRs should presumably be sufficiently rapid to replace both the RTOs and the stable receptors. We have tested this prediction by blocking pre-existing AChRs in the mouse sternomastoid muscle with alpha-bungarotoxin (alpha-BuTx), and monitoring the subsequent appearance of 'new' junctional AChRs at intervals of 3 h to 20 days by labeling them with 125I-alpha-BuTx. The results show that new receptors were initially inserted rapidly (16% at 24 h and 28% at 48 h). The rate of increase of 'new' 125I-alpha-BuTx binding sites gradually slowed down during the remainder of the time period studied. Control observations excluded possible artifacts of the experimental procedure including incomplete blockade of AChRs, dissociation of toxin-receptor complexes, or experimentally induced alteration of receptor synthesis. The present demonstration of rapid synthesis and incorporation of AChRs at innervated neuromuscular junctions provides support for the concept of a subpopulation of rapidly turned over AChRs. The RTOs may serve as precursors for the larger population of stable receptors and have an important role in the metabolism of the neuromuscular synapse.

  5. Mechanical insufflation/exsufflation improves vital capacity in neuromuscular disorders.

    PubMed

    Stehling, Florian; Bouikidis, Anastasios; Schara, Ulrike; Mellies, Uwe

    2015-02-01

    Inherited neuromuscular disorders inevitably result in severe lung volume restriction associated with high morbidity and mortality. The aim of this retrospective study was to evaluate the long-term effects of the regular use of mechanical insufflation/exsufflation on the course of the vital capacity. This retrospective data analysis included 21 patients (16.1 ± 6.5 years) with neuromuscular disorders and severe lung volume restriction using nocturnal noninvasive ventilation. The patients were advised to regularly use the mechanical insufflation/exsufflation twice a day for 10 minutes applying sets of three insufflation/exsufflation breath via face mask irrespective of respiratory tract infection. Data on the course of vital capacity were collected 2 years prior and 2 years after the introduction of regular use of mechanical insufflation/exsufflation. Before the introduction of mechanical insufflation/exsufflation vital capacity decreased from 0.71 ± 0.38 L to 0.50 ± 0.24 L in the last year and from 0.88 ± 0.45 L to 0.71 ± 0.38 L in the next to last year. In the first year, after regular use of mechanical insufflation/exsufflation vital capacity significantly increased by 28% (from 0.50 L to 0.64 L)-after the second year the vital capacity increase remained stable (0.64 vs. 0.65 L). These data suggest that the regular use of mechanical insufflation/exsufflation improves vital capacity in patients with neuromuscular disorders and severe lung volume restriction.

  6. Clinical use of creatine in neuromuscular and neurometabolic disorders.

    PubMed

    Tarnopolsky, Mark A

    2007-01-01

    Many of the neuromuscular (e.g., muscular dystrophy) and neurometabolic (e.g., mitochondrial cytopathies) disorders share similar final common pathways of cellular dysfunction that may be favorably influenced by creatine monohydrate (CrM) supplementation. Studies using the mdx model of Duchenne muscular dystrophy have found evidence of enhanced mitochondrial function, reduced intra-cellular calcium and improved performance with CrM supplementation. Clinical trials in patients with Duchenne and Becker's muscular dystrophy have shown improved function, fat-free mass, and some evidence of improved bone health with CrM supplementation. In contrast, the improvements in function in myotonic dystrophy and inherited neuropathies (e.g., Charcot-Marie-Tooth) have not been significant. Some studies in patients with mitochondrial cytopathies have shown improved muscle endurance and body composition, yet other studies did not find significant improvements in patients with mitochondrial cytopathy. Lower-dose CrM supplementation in patients with McArdle's disease (myophosphorylase deficiency) improved exercise capacity, yet higher doses actually showed some indication of worsened function. Based upon known cellular pathologies, there are potential benefits from CrM supplementation in patients with steroid myopathy, inflammatory myopathy, myoadenylate deaminase deficiency, and fatty acid oxidation defects. Larger randomized control trials (RCT) using homogeneous patient groups and objective and clinically relevant outcome variables are needed to determine whether creatine supplementation will be of therapeutic benefit to patients with neuromuscular or neurometabolic disorders. Given the relatively low prevalence of some of the neuromuscular and neurometabolic disorders, it will be necessary to use surrogate markers of potential clinical efficacy including markers of oxidative stress, cellular energy charge, and gene expression patterns. PMID:18652078

  7. Neuromuscular activity of Bothrops fonsecai snake venom in vertebrate preparations

    PubMed Central

    Fernandes, Carla T; Giaretta, Vânia MA; Prudêncio, Luiz S; Toledo, Edvana O; da Silva, Igor RF; Collaço, Rita CO; Barbosa, Ana M; Hyslop, Stephen; Rodrigues-Simioni, Léa; Cogo, José C

    2014-01-01

    The neuromuscular activity of venom from Bothrops fonsecai, a lancehead endemic to southeastern Brazil, was investigated. Chick biventer cervicis (CBC) and mouse phrenic nerve-diaphragm (PND) preparations were used for myographic recordings and mouse diaphragm muscle was used for membrane resting potential (RP) and miniature end-plate potential (MEPP) recordings. Creatine kinase release and muscle damage were also assessed. In CBC, venom (40, 80 and 160μg/ml) produced concentration- and time-dependent neuromuscular blockade (50% blockade in 85±9 min and 73±8 min with 80 and 160μg/ml, respectively) and attenuated the contractures to 110μM ACh (78–100% inhibition) and 40mM KCl (45–90% inhibition). The venom-induced decrease in twitch-tension in curarized, directly-stimulated preparations was similar to that in indirectly stimulated preparations. Venom (100 and 200μg/ml) also caused blockade in PND preparations (50% blockade in 94±13 min and 49±8 min with 100 and 200μg/ml, respectively) but did not alter the RP or MEPP amplitude. In CBC, venom caused creatine kinase release and myonecrosis. The venom-induced decrease in twitch-tension and in the contractures to ACh and K+ were abolished by preincubating venom with commercial antivenom. These findings indicate that Bothrops fonsecai venom interferes with neuromuscular transmission essentially through postsynaptic muscle damage that affects responses to ACh and KCl. These actions are effectively prevented by commercial antivenom. PMID:25028603

  8. Imaging Acute Neuromuscular Explants from Thy1 Mouse Lines.

    PubMed

    Marinković, Petar; Godinho, Leanne; Misgeld, Thomas

    2015-09-01

    Because core facilities that generate transgenic founder mice for a reasonable fee are now available at most major research institutions, generating new Thy1-XFP transgenic animals (in which XFP stands for any fluorescent protein) is an option even for relatively small laboratories. Here, we provide a protocol for screening offspring of Thy1 transgenic founders. Acute neuromuscular explants are obtained from 3-wk-old F1 mice that have been produced by crossing Thy1 transgenic founders and commercially obtained inbred mice. Thy1-driven expression is detected by fluorescence microscopy. PMID:26330628

  9. Assessing neuromuscular mechanisms in human-exoskeleton interaction.

    PubMed

    Sylla, N; Bonnet, V; Venture, G; Armande, N; Fraisse, P

    2014-01-01

    In this study, we propose to evaluate a 7 DOF exoskeleton in terms of motion control. Using criteria from the human motor control literature, inverse optimization was performed to assess an industrial screwing movement. The results of our study show that the hybrid composition of the free arm movement was accurately determined. At contrary, when wearing the exoskeleton, which produces an arbitrary determined torque compensation, the motion is different from the naturally adopted one. This study is part of the evaluation and comprehension of the complex neuromuscular mechanism resulting in wearing an exoskeleton several hours per day for industrial tasks assistance.

  10. To build a synapse: signaling pathways in neuromuscular junction assembly

    PubMed Central

    Wu, Haitao; Xiong, Wen C.; Mei, Lin

    2010-01-01

    Synapses, as fundamental units of the neural circuitry, enable complex behaviors. The neuromuscular junction (NMJ) is a synapse type that forms between motoneurons and skeletal muscle fibers and that exhibits a high degree of subcellular specialization. Aided by genetic techniques and suitable animal models, studies in the past decade have brought significant progress in identifying NMJ components and assembly mechanisms. This review highlights recent advances in the study of NMJ development, focusing on signaling pathways that are activated by diffusible cues, which shed light on synaptogenesis in the brain and contribute to a better understanding of muscular dystrophy. PMID:20215342

  11. Does quadriceps neuromuscular activation capability explain mobility function among older men and women?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Age-related impairment of neuromuscular activation has been shown to contribute to weakness in older adults. However, it is unclear to what extent impaired neuromuscular activation independently accounts for decline of mobility function. The hypothesis of this study is that capability to produce rap...

  12. Does neuromuscular activation capability explain mobility function among older men and women?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Age-related impairment of neuromuscular activation has been shown to contribute to weakness in older adults. However, it is unclear to what extent impaired neuromuscular activation independently accounts for decline of mobility function. The hypothesis of this study is that capability to produce rap...

  13. Update on neuromuscular disorders in pediatric orthopaedics: Duchenne muscular dystrophy, myelomeningocele, and cerebral palsy.

    PubMed

    Chambers, Henry G

    2014-01-01

    The purpose of this seminar was to review a large range of lower extremity and neuromuscular disorders. Because of the diversity of the topics covered, including clubfoot and vertical talus treatment, management of Legg-Calve-Perthes disease, and limb lengthening in dwarfism, this review will focus on the neuromuscular subsection reviewing the current management of the muscular dystrophies, myelomeningocele, and cerebral palsy.

  14. [Nerve ultrasound is useful for the diagnosis of neuromuscular diseases].

    PubMed

    Noto, Yu-Ichi

    2013-01-01

    High-resolution ultrasound allowed for more detailed morphological assessment peripheral nerves and muscles. It is important to elucidate ultrasound features of peripheral nerves or muscles in various neuromuscular diseases because ultrasound is a widely used, non-invasive and easily accessible diagnostic tool. We attempted to demonstrate characteristic findings of nerve ultrasound in patients with Charcot-Marie-Tooth disease (CMT), Amyotrophic lateral sclerosis (ALS), and Cervical radiculopathy. In patients with CMT1A, cross sectional areas (CSAs) of all the nerves we examined were significantly larger than those in normal controls. Additionally, median nerve CSA had positive correlation with CMT neuropathy score, and negative correlation with nerve conduction velocity. In patients with ALS, increased CSA forearm/upper arm ratio of the median nerve was a characteristic finding to support the diagnosis. In patients with cervical radiculopathy, we could observe that decreased CSA and diameter of the nerve root corresponding to the findings of MRI and electromyography. These results demonstrate that the combination of electrophysiological study, diagnostic imaging, and nerve ultrasound could lead to accurate diagnosis of various neuromuscular diseases.

  15. Neuromuscular and endocrine control of an avian courtship behavior.

    PubMed

    Schlinger, B A; Schultz, J D; Hertel, F

    2001-09-01

    In many species of birds, males perform complex visual and acoustic courtship displays to attract and stimulate females. Some of these displays involve considerable use of the wings and legs, suggesting that they may be controlled by sexually dimorphic spinal motoneurons and their target muscles. Sex steroid hormones are known to organize and activate many sexually dimorphic phenotypes, so these neuromuscular systems may also be steroid sensitive. To test these ideas, we have begun studies of wild golden-collared manakins (Manacus vitellinus) in Central America. Males of this species establish a courtship arena in the forest, where they perform an elaborate dance that includes use of their wings to generate loud snapping sounds. Here we describe male golden-collared manakin courtship behavior, including the various "wingsnaps." We also review our studies, and those of others, showing sexually dimorphic properties of manakin wings, the wing musculature, and sex steroid accumulation in the spinal cord. These data suggest that manakins are useful models for evaluating steroid control of complex peripheral neuromuscular systems. PMID:11534992

  16. Musculoskeletal and neuromuscular interventions: a physical approach to cystic fibrosis.

    PubMed Central

    Massery, Mary

    2005-01-01

    Children with CF are living longer than ever before, and thus issues pertaining to quality of life rather than just longevity of life need to be addressed by the entire healthcare team. This article addressed the issues pertaining to the external support of the dysfunctional internal organs: the secondary musculoskeletal (postural) and neuromuscular control deficits that occur to the maturing child with CF. The research pointed towards starting PT interventions for these deficits during the pre-pubescent phase when postural deficits were just emerging, but a suggestion was also made to explore whether these deficits can be even more effectively monitored and treated at an earlier age. The dual relationship between the muscles used to meet the increased respiratory demands of CF and the normal postural demands of physical activities was described through a model based on a soda-pop can and pressure support. A pre-pubescent child with a typical progression of CF was presented as a case report to illustrate how a PT programme that was focused on postural deficits could be implemented and what type of outcomes might be possible. The child made significant changes within a relatively short time frame of 4 months, proposing that the musculoskeletal and neuromuscular systems may play a significant role in the medical and physical long-term outcomes of CF. For that reason, the physical as well as medical needs of the patient should be incorporated into a comprehensive multi-system approach to the disease across the lifespan. PMID:16025768

  17. Structural abnormalities at neuromuscular synapses lacking multiple syntrophin isoforms.

    PubMed

    Adams, Marvin E; Kramarcy, Neal; Fukuda, Taku; Engel, Andrew G; Sealock, Robert; Froehner, Stanley C

    2004-11-17

    The syntrophins are modular adapter proteins that function by recruiting signaling molecules to the cytoskeleton via their direct association with proteins of the dystrophin protein family. We investigated the physiological function of beta2-syntrophin by generating a line of mice lacking this syntrophin isoform. The beta2-syntrophin null mice show no overt phenotype, or muscular dystrophy, and form structurally normal neuromuscular junctions (NMJs). To determine whether physiological consequences caused by the lack of beta2-syntrophin were masked by compensation from the alpha-syntrophin isoform, we crossed these mice with our previously described alpha-syntrophin null mice to produce mice lacking both isoforms. The alpha/beta2-syntrophin null mice have NMJs that are structurally more aberrant than those lacking only alpha-syntrophin. The NMJs of the alpha/beta2-syntrophin null mice have fewer junctional folds than either parent strain, and the remaining folds are abnormally shaped with few openings to the synaptic space. The levels of acetylcholine receptors are reduced to 23% of wild type in mice lacking both syntrophin isoforms. Furthermore, the alpha/beta2-syntrophin null mice ran significantly shorter distances on voluntary exercise wheels despite having normal neuromuscular junction transmission as determined by micro-electrode recording of endplate potentials. We conclude that both alpha-syntrophin and beta2-syntrophin play distinct roles in forming and maintaining NMJ structure and that each syntrophin can partially compensate for the loss of the other.

  18. Triethylcholine compared with other substances affecting neuromuscular transmission

    PubMed Central

    Bowman, W. C.; Hemsworth, B. A.; Rand, M. J.

    1962-01-01

    Triethylcholine (triethyl-2-hydroxyethyl ammonium) has been compared, in its actions on neuromuscular transmission, with the motor end-plate blocking drugs tubocurarine and decamethonium, with the anticholinesterase neostigmine, and with the closely related drug tetraethylammonium. The experiments were carried out on conscious rabbits and mice, on the tibialis anterior muscle of cats under chloralose anaesthesia and on the isolated phrenic nerve-diaphragm preparation of the rat. Anticholinesterase activity was determined manometrically using the Warburg apparatus. Triethylcholine possessed a slight curare-like action, but this effect was shown to be too weak and transient to contribute to the slowly developing and long-lasting transmission failure which occurs selectively in frequently excited nervemuscle preparations and in exercised conscious animals. It was confirmed that the site of the blocking action of triethylcholine was pre-junctional. Triethylcholine often produced a slight potentiation of the contractions before blocking them. This effect was not due to a depolarizing or an anticholinesterase action, and it was concluded that the slight initial facilitating action of triethylcholine on neuromuscular transmission was due to an increase in the quantity of acetylcholine released by the nerve impulse. Tetraethylammonium was much more powerful than triethylcholine in this respect. The pre-junctional transmission failure produced by triethylcholine could not be explained simply on the basis that an initial excessive release led to exhaustion of transmitter. ImagesFig. 7 PMID:13872106

  19. Sarcocystis fayeri in skeletal muscle of horses with neuromuscular disease.

    PubMed

    Aleman, Monica; Shapiro, Karen; Sisó, Silvia; Williams, Diane C; Rejmanek, Daniel; Aguilar, Beatriz; Conrad, Patricia A

    2016-01-01

    Recent reports of Sarcocystis fayeri-induced toxicity in people consuming horse meat warrant investigation on the prevalence and molecular characterization of Sarcocystis spp. infection in horses. Sarcocysts in skeletal muscle of horses have been commonly regarded as an incidental finding. In this study, we investigated the prevalence of sarcocysts in skeletal muscle of horses with neuromuscular disease. Our findings indicated that S. fayeri infection was common in young mature horses with neuromuscular disease and could be associated with myopathic and neurogenic processes. The number of infected muscles and number of sarcocysts per muscle were significantly higher in diseased than in control horses. S. fayeri was predominantly found in low oxidative highly glycolytic myofibers. This pathogen had a high glycolytic metabolism. Common clinical signs of disease included muscle atrophy, weakness with or without apparent muscle pain, gait deficits, and dysphagia in horses with involvement of the tongue and esophagus. Horses with myositis were lethargic, apparently painful, stiff, and reluctant to move. Similar to humans, sarcocystosis and cardiomyopathy can occur in horses. This study did not establish causality but supported a possible association (8.9% of cases) with disease. The assumption of Sarcocysts spp. being an incidental finding in every case might be inaccurate.

  20. Innervation and neuromuscular control in ageing skeletal muscle.

    PubMed

    Hepple, Russell T; Rice, Charles L

    2016-04-15

    Changes in the neuromuscular system affecting the ageing motor unit manifest structurally as a reduction in motor unit number secondary to motor neuron loss; fibre type grouping due to repeating cycles of denervation-reinnervation; and instability of the neuromuscular junction that may be due to either or both of a gradual perturbation in postsynaptic signalling mechanisms necessary for maintenance of the endplate acetylcholine receptor clusters or a sudden process involving motor neuron death or traumatic injury to the muscle fibre. Functionally, these changes manifest as a reduction in strength and coordination that precedes a loss in muscle mass and contributes to impairments in fatigue. Regular muscle activation in postural muscles or through habitual physical activity can attenuate some of these structural and functional changes up to a point along the ageing continuum. On the other hand, regular muscle activation in advanced age (>75 years) loses its efficacy, and at least in rodents may exacerbate age-related motor neuron death. Transgenic mouse studies aimed at identifying potential mechanisms of motor unit disruptions in ageing muscle are not conclusive due to many different mechanisms converging on similar motor unit alterations, many of which phenocopy ageing muscle. Longitudinal studies of ageing models and humans will help clarify the cause and effect relationships and thus, identify relevant therapeutic targets to better preserve muscle function across the lifespan. PMID:26437581

  1. Intestinal Neuromuscular Function after Preservation and Transplantation1

    PubMed Central

    Hamada, Nobuo; Hutson, William R.; Nakada, Koji; Ikoma, Akira; Suzuki, Tomomi; Zhu, Yue; Starzl, Thomas E.; Todo, Satoru

    2010-01-01

    While it is well known that prolonged preservation of the intestinal graft causes severe mucosal damage after transplantation, little is known about the effect on neuromuscular function. The entire small intestine of adult hound dogs was flushed and preserved with cold lactated Ringer’s solution and autotransplanted either immediately (n = 6) or after 24 hr (n = 6). Animals undergoing sham operation (n = 4) were used as a control. Fasting motility and the response of the intestinal smooth muscle and enteric nerves to bethanechol (100 μg/kg/0.5 hr, iv) and cisapride (0.5 mg/kg, iv) were determined by a multiple strain gauge method on Postoperative Days 2, 4, 7, 14, 21, and 28. Compared to the control, immediately transplanted grafts and those preserved for 24 hr developed delayed reappearance of migrating myoelectric complexes (MMC), hypercontractile activity, and reduced response to bethanechol and cisapride administration. Animals in the preservation group developed more abnormal fasting motility after transplantation, but responses to bethanechol and cisapride stimulation were not markedly different from those of the immediate group. The reappearance of MMC occurred 3 weeks postoperatively in the preservation group compared to 2 days in the immediate group. The results of our study indicate that intestinal dysmotility is augmented in prolonged-preservation grafts compared to those with brief preservation. The dysmotility was transient and normalized 3 to 4 weeks after surgery. Preservation and reperfusion injury to the neuromuscular system of intestinal grafts are reversible and are attenuated by simple hypothermia. PMID:8661243

  2. Proprioception and Neuromuscular Control of the Shoulder After Muscle Fatigue

    PubMed Central

    Myers, Joseph B.; Guskiewicz, Kevin M.; Schneider, Robert A.; Prentice, William E.

    1999-01-01

    Objective: To examine the effects of fatigue on proprioception and neuromuscular control of the shoulder. Design and Setting: Subjects were randomly assigned to either an experimental group or control group. Subjects were tested using either the active angle-reproduction or the single- arm dynamic stability test. The subjects were then fatigued using a dynamometer performing continuous, concentric rotation exercises of the shoulder. Once fatigued, the subjects were posttested using the same test. One week later, the subjects returned and were pretested, fatigued, and posttested using the other test. Subjects: Thirty-two college-age (18 to 25 years) subjects (16 males, 16 females) with no history of glenohumeral instability or upper extremity injury volunteered for this study. Measurements: Absolute angular error was measured using an electrogoniometer present within the isokinetic dynamometer, while sway velocity was measured using a force-plate system. Results: Repeated-measures analysis of variance revealed a significant difference between the pretest and posttest values for absolute angular error in the experimental group, whereas no significant difference was revealed between pretest and posttest sway velocity for either the control or experimental group. Conclusions: Fatigue of the internal and external rotators of the shoulder decreased proprioception of the shoulder, while having no significant effect on neuromuscular control. ImagesFigure 1.Figure 2.Figure 3. PMID:16558590

  3. Measurement of acceleration: a new method of monitoring neuromuscular function.

    PubMed

    Viby-Mogensen, J; Jensen, E; Werner, M; Nielsen, H K

    1988-01-01

    A new method for monitoring neuromuscular function based on measurement of acceleration is presented. The rationale behind the method is Newton's second law, stating that the acceleration is directly proportional to the force. For measurement of acceleration, a piezo-electric ceramic wafer was used. When this piezo electrode was fixed to the thumb, an electrical signal proportional to the acceleration was produced whenever the thumb moved in response to nerve stimulation. The electrical signal was registered and analysed in a Myograph 2000 neuromuscular transmission monitor. In 35 patients anaesthetized with halothane, train-of-four ratios measured with the accelerometer (ACT-TOF) were compared with simultaneous mechanical train-of-four ratios (FDT-TOF). Control ACT-TOF ratios were significantly higher than control FDT-TOF ratios: 116 +/- 12 and 98 +/- 4 (mean +/- s.d.), respectively. In five patients not given any relaxant during the anaesthetic procedure (20-60 min), both responses were remarkably constant. In 30 patients given vecuronium, a close linear relationship was found during recovery between ACT-TOF and FDT-TOF ratios. It is concluded that the method fulfils the basic requirements for a simple and reliable clinical monitoring tool.

  4. Neuromuscular synaptic transmission in aged ganglioside-deficient mice.

    PubMed

    Zitman, Femke M P; Todorov, Boyan; Verschuuren, Jan J; Jacobs, Bart C; Furukawa, Keiko; Furukawa, Koichi; Willison, Hugh J; Plomp, Jaap J

    2011-01-01

    Gangliosides are sialylated glycosphingolipids that are present in high density on neuronal membranes, especially at synapses, where they are assumed to play functional or modulating roles. Mice lacking GM2/GD2-synthase express only the simple gangliosides GD3 and GM3 and develop progressive motor behaviour deficits upon ageing, apparently due to failing complex ganglioside-dependent maintenance and/or repair processes or, alternatively, toxic GM3/GD3 accumulation. We investigated the function of neuromuscular junctions (NMJs) of aged (>9 month-old) GM2/GD2-synthase null-mutant mice, because synaptic dysfunction might develop with age and could potentially contribute to the late-onset motor phenotype. In addition, we studied NMJs of old mice lacking GD3-synthase (expressing only O- and a-series gangliosides), which do not show an overt neurological phenotype but may develop subclinical synaptic deficits. Detailed electrophysiological analyses showed subtle changes in presynaptic neurotransmitter release. Acetylcholine release at 40 Hz nerve stimulation at aged GM2/GD2-synthase null-mutant NMJs ran down slightly more pronounced than at wild-type NMJs, and spontaneous acetylcholine release rate at GD3-synthase null-mutant NMJs was somewhat higher than at wild-type, selectively at 25 °C bath temperature. Interestingly, we observed faster kinetics of postsynaptic electrophysiological responses at aged GD3-synthase null-mutant NMJs, not previously seen by us at NMJs of young GD3-synthase null-mutants or other types of (aged or young) ganglioside-deficient mice. These kinetic changes might reflect a change in postsynaptic acetylcholine receptor behaviour. Our data indicate that it is highly unlikely that transmission failure at NMJs contributes to the progressive motor defects of aged GM2/GD2-synthase null-mutants and that, despite some kinetic changes of synaptic signals, neuromuscular transmission remains successful in aged GD3-synthase null-mutant mice. Apparently

  5. Age‐related neuromuscular changes affecting human vastus lateralis

    PubMed Central

    Piasecki, M.; Ireland, A.; Stashuk, D.; Hamilton‐Wright, A.; Jones, D. A.

    2015-01-01

    Key points Skeletal muscle size and strength decline in older age.The vastus lateralis, a large thigh muscle, undergoes extensive neuromuscular remodelling in healthy ageing, as characterized by a loss of motor neurons, enlargement of surviving motor units and instability of neuromuscular junction transmission.The loss of motor axons and changes to motor unit potential transmission precede a clinically‐relevant loss of muscle mass and function. Abstract The anterior thigh muscles are particularly susceptible to muscle loss and weakness during ageing, although how this is associated with changes to neuromuscular structure and function in terms of motor unit (MU) number, size and MU potential (MUP) stability remains unclear. Intramuscular (I.M.) and surface electromyographic signals were recorded from the vastus lateralis (VL) during voluntary contractions held at 25% maximal knee extensor strength in 22 young (mean ± SD, 25.3 ± 4.8 years) and 20 physically active older men (71.4 ± 6.2 years). MUP size, firing rates, phases, turns and near fibre (NF) jiggle were determined and MU number estimates (MUNEs) were made by comparing average surface MUP with maximal electrically‐evoked compound muscle action potentials. Quadriceps cross‐sectional area was measured by magnetic resonance imaging. In total, 379 individual MUs were sampled in younger men and 346 in older men. Compared to the MU in younger participants, those in older participants had 8% lower firing rates and larger MUP size (+25%), as well as increased complexity, as indicated by phases (+13%), turns (+20%) and NF jiggle (+11%) (all P < 0.0005). The MUNE values (derived from the area of muscle in range of the surface‐electrode) in older participants were ∼70% of those in the young (P < 0.05). Taking into consideration the 30% smaller cross‐sectional area of the VL, the total number of MUs in the older muscles was between 50% and 60% lower compared to in young muscles (P < 0

  6. Neuromuscular medicine competency in physical medicine and rehabilitation residents: a method of development and assessment.

    PubMed

    Lin, Lei; Cuccurullo, Sara J; Innerfield, Caitlin E; Strax, Thomas E; Petagna, Anne

    2013-03-01

    This project endeavored to create an educational module including methodology to instruct physical medicine and rehabilitation residents in the evaluation and appropriate treatment of patients with neuromuscular disorders. It further sought to verify acquired competencies in neuromuscular rehabilitation through objective evaluation methodology. An American Association of Neuromuscular and Electrodiagnostic Medicine board-certified physician with 10 yrs of clinical experience in neuromuscular and general rehabilitation trained 19 residents using a standardized competency-based module. The residents were trained through clinical training, lectures, and review of self-assessment examination concepts from the American Academy of Physical Medicine & Rehabilitation syllabus provided in the Archives of Physical Medicine and Rehabilitation. After delivery of the educational module, knowledge acquisition and skill proficiency were measured in (1) completion of neuromuscular history and physical examination satisfactorily, (2) diagnosis and ability to design a patient care management plan via chart stimulated recall examinations, (3) physician-patient interaction via patient surveys, (4) physician-staff interaction via 360-degree global ratings, and (5) ability to write a comprehensive patient care report and to document a patient care management plan in accordance with Medicare guidelines via written patient reports. Assessment tools developed for this program address the basic competencies outlined by the Accreditation Council for Graduate Medical Education. To test the success of the standardized educational module, data were collected on an ongoing basis. The objective measures compared resident self-assessment examination scores in neuromuscular rehabilitation before and after the institution of the comprehensive neuromuscular competency module in the residency program. Nineteen (100%) of 19 residents successfully demonstrated proficiency in every segment of the

  7. Neuromuscular medicine competency in physical medicine and rehabilitation residents: a method of development and assessment.

    PubMed

    Lin, Lei; Cuccurullo, Sara J; Innerfield, Caitlin E; Strax, Thomas E; Petagna, Anne

    2013-03-01

    This project endeavored to create an educational module including methodology to instruct physical medicine and rehabilitation residents in the evaluation and appropriate treatment of patients with neuromuscular disorders. It further sought to verify acquired competencies in neuromuscular rehabilitation through objective evaluation methodology. An American Association of Neuromuscular and Electrodiagnostic Medicine board-certified physician with 10 yrs of clinical experience in neuromuscular and general rehabilitation trained 19 residents using a standardized competency-based module. The residents were trained through clinical training, lectures, and review of self-assessment examination concepts from the American Academy of Physical Medicine & Rehabilitation syllabus provided in the Archives of Physical Medicine and Rehabilitation. After delivery of the educational module, knowledge acquisition and skill proficiency were measured in (1) completion of neuromuscular history and physical examination satisfactorily, (2) diagnosis and ability to design a patient care management plan via chart stimulated recall examinations, (3) physician-patient interaction via patient surveys, (4) physician-staff interaction via 360-degree global ratings, and (5) ability to write a comprehensive patient care report and to document a patient care management plan in accordance with Medicare guidelines via written patient reports. Assessment tools developed for this program address the basic competencies outlined by the Accreditation Council for Graduate Medical Education. To test the success of the standardized educational module, data were collected on an ongoing basis. The objective measures compared resident self-assessment examination scores in neuromuscular rehabilitation before and after the institution of the comprehensive neuromuscular competency module in the residency program. Nineteen (100%) of 19 residents successfully demonstrated proficiency in every segment of the

  8. Diverticular Disease of the Colon: Neuromuscular Function Abnormalities.

    PubMed

    Bassotti, Gabrio; Villanacci, Vincenzo; Bernardini, Nunzia; Dore, Maria P

    2016-10-01

    Colonic diverticular disease is a frequent finding in daily clinical practice. However, its pathophysiological mechanisms are largely unknown. This condition is likely the result of several concomitant factors occurring together to cause anatomic and functional abnormalities, leading as a result to the outpouching of the colonic mucosa. A pivotal role seems to be played by an abnormal colonic neuromuscular function, as shown repeatedly in these patients, and by an altered visceral perception. There is recent evidence that these abnormalities might be related to the derangement of the enteric innervation, to an abnormal distribution of mucosal neuropeptides, and to low-grade mucosal inflammation. The latter might be responsible for the development of visceral hypersensitivity, often causing abdominal pain in a subset of these patients. PMID:27622368

  9. Isozyme patterns and protein profiles in neuromuscular disorders.

    PubMed

    Edwards, Y H; Tipler, T D; Morgan-Hughes, J A; Neerunjun, J S; Hopkinson, D A

    1982-06-01

    The isozyme patterns of six different enzymes and the polypeptide profiles of soluble proteins have been examined in muscle biopsy specimens from 74 patients with a wide variety of neuromuscular disorders. About half of the samples showed unusual features in at least one, and often several, of the enzymes and proteins tested. The extent of the biochemical abnormalities was roughly proportional to the severity of the disorders. In all cases the unusual isozymes and polypeptide profiles seemed to reflect a reversion to the fetal pattern of gene expression. However, this change appeared to occur in extant muscle and was not dependent on the appearance of new muscle fibres. Among the enzymes, phosphoglycerate mutase followed by creatine kinase appeared to be the most sensitive index of muscle disorder. The extent of the change in the muscle creatine kinase isozyme pattern was not correlated with the levels of serum creatine kinase activity.

  10. Isozyme patterns and protein profiles in neuromuscular disorders.

    PubMed Central

    Edwards, Y H; Tipler, T D; Morgan-Hughes, J A; Neerunjun, J S; Hopkinson, D A

    1982-01-01

    The isozyme patterns of six different enzymes and the polypeptide profiles of soluble proteins have been examined in muscle biopsy specimens from 74 patients with a wide variety of neuromuscular disorders. About half of the samples showed unusual features in at least one, and often several, of the enzymes and proteins tested. The extent of the biochemical abnormalities was roughly proportional to the severity of the disorders. In all cases the unusual isozymes and polypeptide profiles seemed to reflect a reversion to the fetal pattern of gene expression. However, this change appeared to occur in extant muscle and was not dependent on the appearance of new muscle fibres. Among the enzymes, phosphoglycerate mutase followed by creatine kinase appeared to be the most sensitive index of muscle disorder. The extent of the change in the muscle creatine kinase isozyme pattern was not correlated with the levels of serum creatine kinase activity. Images PMID:6286971

  11. Neuromuscular block after intra-arterially injected acetylcholine

    PubMed Central

    Tonali, P.; Gambi, D.

    1973-01-01

    The neuromuscular depolarizing block induced by intra-arterially injected ACh was studied to determine the variability in the same subject and in different subjects without disorders at the motor end-plate. Amplitude of action potentials of the opponens pollicis muscle evoked by intermittent repetitive supramaximal stimulation of the median nerve at the wrist were recorded for one hour from the beginning of ACh injection. The features of prompt and late depression stages after the injection were analysed statistically. Re-testing of the same subjects after a while shows that, in spite of all efforts to maintain the same experimental conditions, variations do occur in late depression. Time course and duration are particularly affected, while the degree of depression is altered but slightly. The presence of such variations limits this test to evaluation of the influence of other factors only within their already established statistical limits. Images PMID:4350703

  12. Presynaptic elements involved in the maintenance of the neuromuscular junction

    NASA Technical Reports Server (NTRS)

    Burrows, G. H.

    1984-01-01

    Alterations in the neuromuscular junction were observed in rats preceding loss of muscle mass. In view of the possibility that these alterations involve changes in the secretion of myotrophic agents by presynaptic motor neurons, an investigation was undertaken to characterize a neuronall factor which is thought to be involved in the initiation and maintenance of cholinergic synapses. This factor, which is secreted into the incubation medium by NG108-15 neuroblastoma x glioma hybrid cells, induces the aggregation of nicotinic acetylcholine receptors on primary cultures of rat hindlimb myotubes. Previous attempts to purify this factor failed. Extensive washing of the NG108-15 cells with hepes-buffered salt solution followed by short (4 hour) collection times resulted in the collection of incubation medium containing maximal aggregation activity with as little as 5 ug secreted protein per ml of fresh medium. A three-fold increase in specific activity was obtained after anion exchange chromatography.

  13. A novel synaptic plasticity rule explains homeostasis of neuromuscular transmission

    PubMed Central

    Ouanounou, Gilles; Baux, Gérard; Bal, Thierry

    2016-01-01

    Excitability differs among muscle fibers and undergoes continuous changes during development and growth, yet the neuromuscular synapse maintains a remarkable fidelity of execution. Here we show in two evolutionarily distant vertebrates (Xenopus laevis cell culture and mouse nerve-muscle ex-vivo) that the skeletal muscle cell constantly senses, through two identified calcium signals, synaptic events and their efficacy in eliciting spikes. These sensors trigger retrograde signal(s) that control presynaptic neurotransmitter release, resulting in synaptic potentiation or depression. In the absence of spikes, synaptic events trigger potentiation. Once the synapse is sufficiently strong to initiate spiking, the occurrence of these spikes activates a negative retrograde feedback. These opposing signals dynamically balance the synapse in order to continuously adjust neurotransmitter release to a level matching current muscle cell excitability. DOI: http://dx.doi.org/10.7554/eLife.12190.001 PMID:27138195

  14. Systemic inflammatory response and neuromuscular involvement in amyotrophic lateral sclerosis

    PubMed Central

    Lu, Ching-Hua; Allen, Kezia; Oei, Felicia; Leoni, Emanuela; Kuhle, Jens; Tree, Timothy; Fratta, Pietro; Sharma, Nikhil; Sidle, Katie; Howard, Robin; Orrell, Richard; Fish, Mark; Greensmith, Linda; Pearce, Neil; Gallo, Valentina

    2016-01-01

    Objective: To evaluate the combined blood expression of neuromuscular and inflammatory biomarkers as predictors of disease progression and prognosis in amyotrophic lateral sclerosis (ALS). Methods: Logistic regression adjusted for markers of the systemic inflammatory state and principal component analysis were carried out on plasma levels of creatine kinase (CK), ferritin, and 11 cytokines measured in 95 patients with ALS and 88 healthy controls. Levels of circulating biomarkers were used to study survival by Cox regression analysis and correlated with disease progression and neurofilament light chain (NfL) levels available from a previous study. Cytokines expression was also tested in blood samples longitudinally collected for up to 4 years from 59 patients with ALS. Results: Significantly higher levels of CK, ferritin, tumor necrosis factor (TNF)–α, and interleukin (IL)–1β, IL-2, IL-8, IL-12p70, IL-4, IL-5, IL-10, and IL-13 and lower levels of interferon (IFN)–γ were found in plasma samples from patients with ALS compared to controls. IL-6, TNF-α, and IFN-γ were the most highly regulated markers when all explanatory variables were jointly analyzed. High ferritin and IL-2 levels were predictors of poor survival. IL-5 levels were positively correlated with CK, as was TNF-α with NfL. IL-6 was strongly associated with CRP levels and was the only marker showing increasing expression towards end-stage disease in the longitudinal analysis. Conclusions: Neuromuscular pathology in ALS involves the systemic regulation of inflammatory markers mostly active on T-cell immune responses. Disease stratification based on the prognostic value of circulating inflammatory markers could improve clinical trials design in ALS. PMID:27308305

  15. Combined application of neuromuscular electrical stimulation and voluntary muscular contractions.

    PubMed

    Paillard, Thierry

    2008-01-01

    Electromyostimulation (EMS) and voluntary muscle contraction (VC) constitute different modes of muscle activation and induce different acute physiological effects on the neuromuscular system. Long-term application of each mode of muscle activation can produce different muscle adaptations. It seems theoretically possible to completely or partially cumulate the muscle adaptations induced by each mode of muscle activation applied separately. This work consisted of examining the literature concerning the muscle adaptations induced by long-term application of the combined technique (CT) [i.e. EMS is combined with VC - non-simultaneously] compared with VC and/or EMS alone in healthy subjects and/or athletes and in post-operative knee-injured subjects. In general, CT induced greater muscular adaptations than VC whether in sports training or rehabilitation. This efficiency would be due to the fact that CT can facilitate cumulative effects of training completely or partially induced by VC and EMS practiced alone. CT also provides a greater improvement of the performance of complex dynamic movements than VC. However, EMS cannot improve coordination between different agonistic and antagonistic muscles and thus does not facilitate learning the specific coordination of complex movements. Hence, EMS should be combined with specific sport training to generate neuromuscular adaptations, but also allow the adjustment of motor control during a voluntary movement. Likewise, in a therapeutic context, CT was particularly efficient to accelerate recovery of muscle contractility during a rehabilitation programme. Strength loss and atrophy inherent in a traumatism and/or a surgical operation would be more efficiently compensated with CT than with VC. Furthermore, CT also restored more functional abilities than VC. Finally, in a rehabilitation context, EMS is complementary to voluntary exercise because in the early phase of rehabilitation it elicits a strength increase, which is necessary

  16. Neuromuscular Strain Increases Symptom Intensity in Chronic Fatigue Syndrome

    PubMed Central

    Rowe, Peter C.; Fontaine, Kevin R.; Lauver, Megan; Jasion, Samantha E.; Marden, Colleen L.; Moni, Malini; Thompson, Carol B.; Violand, Richard L.

    2016-01-01

    Chronic fatigue syndrome (CFS) is a complex, multisystem disorder that can be disabling. CFS symptoms can be provoked by increased physical or cognitive activity, and by orthostatic stress. In preliminary work, we noted that CFS symptoms also could be provoked by application of longitudinal neural and soft tissue strain to the limbs and spine of affected individuals. In this study we measured the responses to a straight leg raise neuromuscular strain maneuver in individuals with CFS and healthy controls. We randomly assigned 60 individuals with CFS and 20 healthy controls to either a 15 minute period of passive supine straight leg raise (true neuromuscular strain) or a sham straight leg raise. The primary outcome measure was the symptom intensity difference between the scores during and 24 hours after the study maneuver compared to baseline. Fatigue, body pain, lightheadedness, concentration difficulties, and headache scores were measured individually on a 0–10 scale, and summed to create a composite symptom score. Compared to individuals with CFS in the sham strain group, those with CFS in the true strain group reported significantly increased body pain (P = 0.04) and concentration difficulties (P = 0.02) as well as increased composite symptom scores (all P = 0.03) during the maneuver. After 24 hours, the symptom intensity differences were significantly greater for the CFS true strain group for the individual symptom of lightheadedness (P = 0.001) and for the composite symptom score (P = 0.005). During and 24 hours after the exposure to the true strain maneuver, those with CFS had significantly higher individual and composite symptom intensity changes compared to the healthy controls. We conclude that a longitudinal strain applied to the nerves and soft tissues of the lower limb is capable of increasing symptom intensity in individuals with CFS for up to 24 hours. These findings support our preliminary observations that increased mechanical sensitivity may be a

  17. Effects of neuromuscular lags on controlling contact transitions

    PubMed Central

    Venkadesan, Madhusudhan; Valero-Cuevas, Francisco J.

    2009-01-01

    We present a numerical exploration of contact transitions with the fingertip. When picking up objects our fingertips must make contact at specific locations, and—upon contact—maintain posture while producing well-directed force vectors. However, the joint torques for moving the fingertip towards a surface (τm) are different from those for producing static force vectors (τf). We previously described the neural control of such abrupt transitions in humans, and found that unavoidable errors arise because sensorimotor time delays and lags prevent an instantaneous switch between different torques. Here, we use numerical optimization on a finger model to reveal physical bounds for controlling such rapid contact transitions. Resembling human data, it is necessary to anticipatorily switch joint torques to τf at about 30 ms before contact to minimize the initial misdirection of the fingertip force vector. This anticipatory strategy arises in our deterministic model from neuromuscular lags, and not from optimizing for robustness to noise/uncertainties. Importantly, the optimal solution also leads to a trade-off between the speed of force magnitude increase versus the accuracy of initial force direction. This is an alternative to prevailing theories that propose multiplicative noise in muscles as the driver of speed–accuracy trade-offs. We instead find that the speed–accuracy trade-off arises solely from neuromuscular lags. Finally, because our model intentionally uses idealized assumptions, its agreement with human data suggests that the biological system is controlled in a way that approaches the physical boundaries of performance. PMID:19218157

  18. Effects of neuromuscular lags on controlling contact transitions.

    PubMed

    Venkadesan, Madhusudhan; Valero-Cuevas, Francisco J

    2009-03-28

    We present a numerical exploration of contact transitions with the fingertip. When picking up objects our fingertips must make contact at specific locations, and-upon contact-maintain posture while producing well-directed force vectors. However, the joint torques for moving the fingertip towards a surface (tau(m)) are different from those for producing static force vectors (tau(f)). We previously described the neural control of such abrupt transitions in humans, and found that unavoidable errors arise because sensorimotor time delays and lags prevent an instantaneous switch between different torques. Here, we use numerical optimization on a finger model to reveal physical bounds for controlling such rapid contact transitions. Resembling human data, it is necessary to anticipatorily switch joint torques to tau(f )at about 30 ms before contact to minimize the initial misdirection of the fingertip force vector. This anticipatory strategy arises in our deterministic model from neuromuscular lags, and not from optimizing for robustness to noise/uncertainties. Importantly, the optimal solution also leads to a trade-off between the speed of force magnitude increase versus the accuracy of initial force direction. This is an alternative to prevailing theories that propose multiplicative noise in muscles as the driver of speed-accuracy trade-offs. We instead find that the speed-accuracy trade-off arises solely from neuromuscular lags. Finally, because our model intentionally uses idealized assumptions, its agreement with human data suggests that the biological system is controlled in a way that approaches the physical boundaries of performance.

  19. THREE-DIMENSIONAL ULTRASTRUCTURE OF THE CRAYFISH NEUROMUSCULAR APPARATUS

    PubMed Central

    Jahromi, S. S.; Atwood, H. L.

    1974-01-01

    The synapse-bearing nerve terminals of the opener muscle of the crayfish Procambarus were reconstructed using electron micrographs of regions which had been serially sectioned. The branching patterns of the terminals of excitatory and inhibitory axons and the locations and sizes of neuromuscular and axo-axonal synapses were studied. Excitatory and inhibitory synapses could be distinguished not only on the basis of differences in synaptic vesicles, but also by a difference in density of pre- and postsynaptic membranes. Synapses of both axons usually had one or more sharply localized presynaptic "dense bodies" around which synaptic vesicles appeared to cluster. Some synapses did not have the dense bodies. These structures may be involved in the physiological activity of the synapse. Excitatory axon terminals had more synapses, and a larger percentage of terminal surface area devoted to synaptic contacts, than inhibitory axon terminals. However, the largest synapses of the inhibitory axon exceeded in surface area those of the excitatory axon. Both axons had many side branches coming from the main terminal; often, the side branches were joined to the main terminal by narrow necks. A greater percentage of surface area was devoted to synapses in side branches than in the main terminal. Only a small fraction of total surface area was devoted to axo-axonal synapses, but these were often located at narrow necks or constrictions of the excitatory axon. This arrangement would result in effective blockage of spike invasion of regions of the terminal distal to the synapse, and would allow relatively few synapses to exert a powerful effect on transmitter release from the excitatory axon. A hypothesis to account for the development of the neuromuscular apparatus is presented, in which it is suggested that production of new synapses is more important than enlargement of old ones as a mechanism for allowing the axon to adjust transmitter output to the functional needs of the muscle

  20. Neuromuscular adaptations and correlates of knee functionality following ACL reconstruction.

    PubMed

    Bryant, Adam L; Kelly, Jason; Hohmann, Erik

    2008-01-01

    The objective of this research was to examine the dynamic restraint mechanism by establishing the neuromuscular characteristics of lower extremity muscles in anterior cruciate ligament reconstruction (ACLR) subjects. This study also investigated neuromuscular variables that relate to post-ACLR functional outcome. Thirteen patients having undergone ACLR using the bone patella tendon bone graft at least 6 months prior participated in this study. Knee functionality (0- to 100-point scale) was rated using the Cincinnati Knee Rating System. The median frequency of the electromyographic (EMG) recordings from the vastus medialis (VM) and vastus lateralis (VL) muscles together with the isokinetic quadriceps torque generated in 10 degrees intervals between 80 degrees and 10 degrees knee flexion was determined for the noninvolved and involved limbs. Lower limb musculotendinous stiffness was also assessed for the noninvolved and involved limbs. Limb symmetry indexes were calculated for each of the physiological measures. Compared to the noninvolved limb, the median frequency of the EMG from the involved limb VM and VL muscles was significantly lower as was the quadriceps torque generated at the seven knee flexion intervals. In contrast, musculotendinous stiffness was significantly higher in the involved lower limb compared to the noninvolved limb. Significant, moderate correlations were identified between knee functionality and symmetry indexes for all variables except for the isokinetic quadriceps torque produced between 80 degrees -70 degrees and 20 degrees -10 degrees knee flexion. More functional ACLR subjects demonstrated enhanced motor unit recruitment reflective of less quadriceps muscle fiber atrophy together with increased quadriceps strength and musculotendinous stiffness of the lower limb musculature.

  1. Neuromuscular Strain Increases Symptom Intensity in Chronic Fatigue Syndrome.

    PubMed

    Rowe, Peter C; Fontaine, Kevin R; Lauver, Megan; Jasion, Samantha E; Marden, Colleen L; Moni, Malini; Thompson, Carol B; Violand, Richard L

    2016-01-01

    Chronic fatigue syndrome (CFS) is a complex, multisystem disorder that can be disabling. CFS symptoms can be provoked by increased physical or cognitive activity, and by orthostatic stress. In preliminary work, we noted that CFS symptoms also could be provoked by application of longitudinal neural and soft tissue strain to the limbs and spine of affected individuals. In this study we measured the responses to a straight leg raise neuromuscular strain maneuver in individuals with CFS and healthy controls. We randomly assigned 60 individuals with CFS and 20 healthy controls to either a 15 minute period of passive supine straight leg raise (true neuromuscular strain) or a sham straight leg raise. The primary outcome measure was the symptom intensity difference between the scores during and 24 hours after the study maneuver compared to baseline. Fatigue, body pain, lightheadedness, concentration difficulties, and headache scores were measured individually on a 0-10 scale, and summed to create a composite symptom score. Compared to individuals with CFS in the sham strain group, those with CFS in the true strain group reported significantly increased body pain (P = 0.04) and concentration difficulties (P = 0.02) as well as increased composite symptom scores (all P = 0.03) during the maneuver. After 24 hours, the symptom intensity differences were significantly greater for the CFS true strain group for the individual symptom of lightheadedness (P = 0.001) and for the composite symptom score (P = 0.005). During and 24 hours after the exposure to the true strain maneuver, those with CFS had significantly higher individual and composite symptom intensity changes compared to the healthy controls. We conclude that a longitudinal strain applied to the nerves and soft tissues of the lower limb is capable of increasing symptom intensity in individuals with CFS for up to 24 hours. These findings support our preliminary observations that increased mechanical sensitivity may be a

  2. [Genetic defects and disorders at the neuromuscular junction].

    PubMed

    Ohno, Kinji

    2011-07-01

    Genetic defects in molecules expressed at the neuromuscular junction (NMJ) cause congenital myasthenic syndromes (CMSs), which are characterized by muscle weakness, abnormal fatigability, amyotrophy, and minor facial anomalies. Muscle weakness mostly develops under 2 years but is also sometimes seen in adults. Mutations identified to date include (i) muscle nicotinic acetylcholine receptor (AChR) subunits, (ii) rapsyn that anchors and clusters AChRs at the neuromuscular junction, (iii) agrin that is released from the nerve terminal and induces AChR clustering by stimulating the downstream LRP4/MuSK/Dok-7/rapsyn/AChR pathway, (iv) muscle-specific kinase (MuSK) that transmits the AChR-clustering signal from agrin/LRP4 to rapsyn/AChR, (v) Dok-7 that transmits the AChR-clustering signal from agrin/LRP4/MuSK to rapsyn/AChR, (vi) skeletal muscle sodium channel type 1.4 (Nav1.4) that spreads the depolarization potential from the endplate throughout muscle fibers, (vii) collagen Q that anchors acetylcholinesterase to the synaptic basal lamina, and (viii) choline acetyltransferase that resynthesizes acetylcholine from recycled choline at the nerve terminal. In addition, mutations in the heparin sulfate proteoglycan perlecan, which binds to many molecules including collagen Q and dystroglycan, causes Schwartz-Jampel syndrome. Interestingly, mutations in LRP4 cause Cenani-Lenz syndactyly syndrome but not CMS. AChR, MuSK, and LRP4 are also targets of auto-antibodies in myasthenia gravis. In addition, molecules at the NMJ are targets of many other disease states AChRs are blocked by the snake toxin alpha-bungarotoxin and the plant poison curare. The presynaptic SNARE complex is attacked by botulinum toxin. Acetylcholinesterase is inhibited by the nerve gas sarin and by organophosphate pesticides. This review focuses on the molecular bases underlying defects of AChR, rapsyn, Nav1.4, collagen Q, and choline acetyltransferase. PMID:21747136

  3. LRP4 is critical for neuromuscular junction maintenance.

    PubMed

    Barik, Arnab; Lu, Yisheng; Sathyamurthy, Anupama; Bowman, Andrew; Shen, Chengyong; Li, Lei; Xiong, Wen-cheng; Mei, Lin

    2014-10-15

    The neuromuscular junction (NMJ) is a synapse between motor neurons and skeletal muscle fibers, and is critical for control of muscle contraction. Its formation requires neuronal agrin that acts by binding to LRP4 to stimulate MuSK. Mutations have been identified in agrin, MuSK, and LRP4 in patients with congenital myasthenic syndrome, and patients with myasthenia gravis develop antibodies against agrin, LRP4, and MuSK. However, it remains unclear whether the agrin signaling pathway is critical for NMJ maintenance because null mutation of any of the three genes is perinatal lethal. In this study, we generated imKO mice, a mutant strain whose LRP4 gene can be deleted in muscles by doxycycline (Dox) treatment. Ablation of the LRP4 gene in adult muscle enabled studies of its role in NMJ maintenance. We demonstrate that Dox treatment of P30 mice reduced muscle strength and compound muscle action potentials. AChR clusters became fragmented with diminished junctional folds and synaptic vesicles. The amplitude and frequency of miniature endplate potentials were reduced, indicating impaired neuromuscular transmission and providing cellular mechanisms of adult LRP4 deficiency. We showed that LRP4 ablation led to the loss of synaptic agrin and the 90 kDa fragments, which occurred ahead of other prejunctional and postjunctional components, suggesting that LRP4 may regulate the stability of synaptic agrin. These observations demonstrate that LRP4 is essential for maintaining the structural and functional integrity of the NMJ and that loss of muscle LRP4 in adulthood alone is sufficient to cause myasthenic symptoms. PMID:25319686

  4. LRP4 Is Critical for Neuromuscular Junction Maintenance

    PubMed Central

    Barik, Arnab; Lu, Yisheng; Sathyamurthy, Anupama; Bowman, Andrew; Shen, Chengyong; Li, Lei; Xiong, Wen-cheng

    2014-01-01

    The neuromuscular junction (NMJ) is a synapse between motor neurons and skeletal muscle fibers, and is critical for control of muscle contraction. Its formation requires neuronal agrin that acts by binding to LRP4 to stimulate MuSK. Mutations have been identified in agrin, MuSK, and LRP4 in patients with congenital myasthenic syndrome, and patients with myasthenia gravis develop antibodies against agrin, LRP4, and MuSK. However, it remains unclear whether the agrin signaling pathway is critical for NMJ maintenance because null mutation of any of the three genes is perinatal lethal. In this study, we generated imKO mice, a mutant strain whose LRP4 gene can be deleted in muscles by doxycycline (Dox) treatment. Ablation of the LRP4 gene in adult muscle enabled studies of its role in NMJ maintenance. We demonstrate that Dox treatment of P30 mice reduced muscle strength and compound muscle action potentials. AChR clusters became fragmented with diminished junctional folds and synaptic vesicles. The amplitude and frequency of miniature endplate potentials were reduced, indicating impaired neuromuscular transmission and providing cellular mechanisms of adult LRP4 deficiency. We showed that LRP4 ablation led to the loss of synaptic agrin and the 90 kDa fragments, which occurred ahead of other prejunctional and postjunctional components, suggesting that LRP4 may regulate the stability of synaptic agrin. These observations demonstrate that LRP4 is essential for maintaining the structural and functional integrity of the NMJ and that loss of muscle LRP4 in adulthood alone is sufficient to cause myasthenic symptoms. PMID:25319686

  5. [THE VIBRATION TRAINING AS SARCOPENIA INTERVENTION: IMPACT ON THE NEUROMUSCULAR SYSTEM OF THE ELDERLY].

    PubMed

    Palop Montoro, María Victoria; Párraga Montilla, Juan Antonio; Lozano Aguilera, Emilio; Arteaga Checa, Milagros

    2015-10-01

    Introducción: el envejecimiento se acompaña de una reducción progresiva de la masa muscular que contribuye al desarrollo de limitaciones funcionales, donde el entrenamiento vibratorio puede ser una opción de intervención óptima en la prevención y tratamiento de la sarcopenia. Objetivo: comprobar la efectividad del entrenamiento de vibraciones de cuerpo completo en el sistema neuromuscular de los adultos mayores. Métodos: revisión sistemática en las bases de datos Medline, CINAHL, WOS y PEDro, mediante la combinación de los descriptores del Medical Subjects Headings (MeSH) referentes a entrenamiento vibratorio, fuerza muscular, masa muscular y personas mayores. Resultados: fueron encontrados un total de 214 estudios sobre el entrenamiento vibratorio en personas mayores, bien como única intervención o en combinación con otros ejercicios, de los cuales 45 cumplían los criterios de selección. De ellos, 30 artículos fueron eliminados por no superar los 5 puntos según la escala de PEDro. Se incluyeron para el análisis final 15 ensayos clínicos. Conclusión: el entrenamiento con plataformas vibratorias demuestra ser un método de entrenamiento de la fuerza seguro, adecuado y eficaz para la población de mayor edad, pero con resultados similares al ejercicio de resistencia convencional, en la prevención y tratamiento de la sarcopenia.

  6. Impaired voluntary neuromuscular activation limits muscle power in mobility-limited older adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background. Age-related alterations of neuromuscular activation may contribute to deficits in muscle power and mobility function. This study assesses whether impaired activation of the agonist quadriceps and antagonist hamstrings, including amplitude- and velocity-dependent characteristics of activa...

  7. Neuromuscular activity of Bothrops alcatraz snake venom in chick biventer cervicis preparations.

    PubMed

    de Moraes, Delkia Seabra; Aparecido de Abreu, Valdemir; Rostelato-Ferreira, Sandro; Leite, Gildo B; Alice da Cruz-Höfling, Maria; Travaglia-Cardoso, Silvia R; Hyslop, Stephen; Rodrigues-Simioni, Léa

    2012-02-01

    Venom (10-100 μg/ml) from Bothrops alcatraz, a pitviper from the Alcatrazes Archipelago off the coast of southeastern Brazil, caused progressive, irreversible neuromuscular blockade in chick isolated biventer cervicis preparations. The venom also inhibited contractures to exogenous ACh (110 μM) and KCl (20 mM), caused myofiber damage and increased creatine kinase release. Commercial bothropic antivenom raised against mainland Bothrops species neutralized the neuromuscular activity, depending on the venom concentration. PMID:22155137

  8. Update on neuromuscular disorders in pediatric orthopaedics: Duchenne muscular dystrophy, myelomeningocele, and cerebral palsy.

    PubMed

    Chambers, Henry G

    2014-01-01

    The purpose of this seminar was to review a large range of lower extremity and neuromuscular disorders. Because of the diversity of the topics covered, including clubfoot and vertical talus treatment, management of Legg-Calve-Perthes disease, and limb lengthening in dwarfism, this review will focus on the neuromuscular subsection reviewing the current management of the muscular dystrophies, myelomeningocele, and cerebral palsy. PMID:25207736

  9. Effects of neuromuscular training on knee joint stability after anterior cruciate ligament reconstruction

    PubMed Central

    Shim, Jae-Kwang; Choi, Ho-Suk; Shin, Jun-Ho

    2015-01-01

    [Purpose] This study examined the effects of neuromuscular training on knee joint stability after anterior cruciate ligament reconstruction. [Subjects and Methods] The subjects were 16 adults who underwent arthroscopic anterior cruciate reconstruction and neuromuscular training. The Lysholm scale was used to assess functional disorders on the affected knee joint. A KT-2000 arthrometer was used to measure anterior displacement of the tibia against the femur. Surface electromyography was used to detect the muscle activation of the vastus medialis oblique, vastus lateralis, biceps femoris, and semitendinosus before and after neuromuscular training. [Results] There was significant relaxation in tibial anterior displacement of the affected and sound sides in the supine position before neuromuscular training. Furthermore, the difference in the tibial anterior displacement of the affected knee joints in the standing position was reduced after neuromuscular training. Moreover, the variation of the muscle activation evoked higher muscle activation of the vastus medialis oblique, vastus lateralis, biceps femoris, and semitendinosus. [Conclusion] Neuromuscular training may improve functional joint stability in patients with orthopedic musculoskeletal injuries in the postoperative period. PMID:26834316

  10. Effects of neuromuscular training on knee joint stability after anterior cruciate ligament reconstruction.

    PubMed

    Shim, Jae-Kwang; Choi, Ho-Suk; Shin, Jun-Ho

    2015-12-01

    [Purpose] This study examined the effects of neuromuscular training on knee joint stability after anterior cruciate ligament reconstruction. [Subjects and Methods] The subjects were 16 adults who underwent arthroscopic anterior cruciate reconstruction and neuromuscular training. The Lysholm scale was used to assess functional disorders on the affected knee joint. A KT-2000 arthrometer was used to measure anterior displacement of the tibia against the femur. Surface electromyography was used to detect the muscle activation of the vastus medialis oblique, vastus lateralis, biceps femoris, and semitendinosus before and after neuromuscular training. [Results] There was significant relaxation in tibial anterior displacement of the affected and sound sides in the supine position before neuromuscular training. Furthermore, the difference in the tibial anterior displacement of the affected knee joints in the standing position was reduced after neuromuscular training. Moreover, the variation of the muscle activation evoked higher muscle activation of the vastus medialis oblique, vastus lateralis, biceps femoris, and semitendinosus. [Conclusion] Neuromuscular training may improve functional joint stability in patients with orthopedic musculoskeletal injuries in the postoperative period.

  11. Presynaptic action of trifluoperazine at the frog neuromuscular junction.

    PubMed

    Publicover, S J

    1983-02-01

    Treatment of frog neuromuscular preparations bathed in basic frog saline (1.8 mM Ca2+) with trifluoperazine (25 microM) caused an increase in MEPP frequency in 6 out of 10 preparations tested. The mean normalised MEPP frequency after 15 min of treatment was approximately 1.5. 10 microM trifluoperazine had a similar effect. In salines containing low concentrations of Ca2+ (50 microM Ca2+, 2 mM Mg2+ or 0 Ca2+, 1 mM EGTA) the stimulatory action of trifluoperazine was more marked and occurred in a higher proportion of the preparations tested (11 out of 14). When evoked release of transmitter was reduced to very low levels by Mg2+-containing salines treatment with trifluoperazine (2.5-25 microM) caused an increase in quantal content of 20-60%. Depolarisation of preparations bathed in standard frog saline by increasing [K+]o to 10 mM resulted in a 10-fold increase in MEPP frequency. This response was inhibited by about 25% in 10 microM trifluoperazine and by about 45% in 25 microM trifluoperazine. Pre-treatment of preparations with trifluoperazine (25 microM) caused a marked reduction in the response of MEPP frequency to tetanic stimulation (50 Hz) both in the presence of an inward electrochemical gradient for Ca2+ (50 microM Ca2+, 2 mM Mg2+) and in a Ca2+-free saline (0 Ca2+, 1 mM EGTA). The effects of trifluoperazine on tetanic enhancement of MEPP frequency are compared to those of other agents and it is shown that the results are inconsistent with an effect of the drug on Ca2+-fluxes at the plasma membrane. It is concluded that trifluoperazine has both stimulatory and inhibitory effects on transmitter release at the frog neuromuscular junction and that the inhibitory effect is probably due to inhibition of excitation-secretion coupling at a point subsequent to Ca2+ mobilization.

  12. TMEM184b Promotes Axon Degeneration and Neuromuscular Junction Maintenance

    PubMed Central

    Geisler, Stefanie; Pittman, Sara K.; Doan, Ryan A.; Weihl, Conrad C.; Milbrandt, Jeffrey; DiAntonio, Aaron

    2016-01-01

    Complex nervous systems achieve proper connectivity during development and must maintain these connections throughout life. The processes of axon and synaptic maintenance and axon degeneration after injury are jointly controlled by a number of proteins within neurons, including ubiquitin ligases and mitogen activated protein kinases. However, our understanding of these molecular cascades is incomplete. Here we describe the phenotype resulting from mutation of TMEM184b, a protein identified in a screen for axon degeneration mediators. TMEM184b is highly expressed in the mouse nervous system and is found in recycling endosomes in neuronal cell bodies and axons. Disruption of TMEM184b expression results in prolonged maintenance of peripheral axons following nerve injury, demonstrating a role for TMEM184b in axon degeneration. In contrast to this protective phenotype in axons, uninjured mutant mice have anatomical and functional impairments in the peripheral nervous system. Loss of TMEM184b causes swellings at neuromuscular junctions that become more numerous with age, demonstrating that TMEM184b is critical for the maintenance of synaptic architecture. These swellings contain abnormal multivesicular structures similar to those seen in patients with neurodegenerative disorders. Mutant animals also show abnormal sensory terminal morphology. TMEM184b mutant animals are deficient on the inverted screen test, illustrating a role for TMEM184b in sensory-motor function. Overall, we have identified an important function for TMEM184b in peripheral nerve terminal structure, function, and the axon degeneration pathway. SIGNIFICANCE STATEMENT Our work has identified both neuroprotective and neurodegenerative roles for a previously undescribed protein, TMEM184b. TMEM184b mutation causes delayed axon degeneration following peripheral nerve injury, indicating that it participates in the degeneration process. Simultaneously, TMEM184b mutation causes progressive structural

  13. Verifax: Biometric instruments measuring neuromuscular disorders/performance impairments

    NASA Astrophysics Data System (ADS)

    Morgenthaler, George W.; Shrairman, Ruth; Landau, Alexander

    1998-01-01

    VeriFax, founded in 1990 by Dr. Ruth Shrairman and Mr. Alex Landau, began operations with the aim of developing a biometric tool for the verification of signatures from a distance. In the course of developing this VeriFax Autograph technology, two other related applications for the technologies under development at VeriFax became apparent. The first application was in the use of biometric measurements as clinical monitoring tools for physicians investigating neuromuscular diseases (embodied in VeriFax's Neuroskill technology). The second application was to evaluate persons with critical skills (e.g., airline pilots, bus drivers) for physical and mental performance impairments caused by stress, physiological disorders, alcohol, drug abuse, etc. (represented by VeriFax's Impairoscope prototype instrument). This last application raised the possibility of using a space-qualified Impairoscope variant to evaluate astronaut performance with respect to the impacts of stress, fatigue, excessive workload, build-up of toxic chemicals within the space habitat, etc. The three applications of VeriFax's patented technology are accomplished by application-specific modifications of the customized VeriFax software. Strong commercial market potentials exist for all three VeriFax technology applications, and market progress will be presented in more detail below.

  14. Applications of shape memory alloys for neurology and neuromuscular rehabilitation.

    PubMed

    Pittaccio, Simone; Garavaglia, Lorenzo; Ceriotti, Carlo; Passaretti, Francesca

    2015-01-01

    Shape memory alloys (SMAs) are a very promising class of metallic materials that display interesting nonlinear properties, such as pseudoelasticity (PE), shape memory effect (SME) and damping capacity, due to high mechanical hysteresis and internal friction. Our group has applied SMA in the field of neuromuscular rehabilitation, designing some new devices based on the mentioned SMA properties: in particular, a new type of orthosis for spastic limb repositioning, which allows residual voluntary movement of the impaired limb and has no predetermined final target position, but follows and supports muscular elongation in a dynamic and compliant way. Considering patients in the sub-acute phase after a neurological lesion, and possibly bedridden, the paper presents a mobiliser for the ankle joint, which is designed exploiting the SME to provide passive exercise to the paretic lower limb. Two different SMA-based applications in the field of neuroscience are then presented, a guide and a limb mobiliser specially designed to be compatible with diagnostic instrumentations that impose rigid constraints in terms of electromagnetic compatibility and noise distortion. Finally, the paper discusses possible uses of these materials in the treatment of movement disorders, such as dystonia or hyperkinesia, where their dynamic characteristics can be advantageous. PMID:26023790

  15. Applications of Shape Memory Alloys for Neurology and Neuromuscular Rehabilitation

    PubMed Central

    Pittaccio, Simone; Garavaglia, Lorenzo; Ceriotti, Carlo; Passaretti, Francesca

    2015-01-01

    Shape memory alloys (SMAs) are a very promising class of metallic materials that display interesting nonlinear properties, such as pseudoelasticity (PE), shape memory effect (SME) and damping capacity, due to high mechanical hysteresis and internal friction. Our group has applied SMA in the field of neuromuscular rehabilitation, designing some new devices based on the mentioned SMA properties: in particular, a new type of orthosis for spastic limb repositioning, which allows residual voluntary movement of the impaired limb and has no predetermined final target position, but follows and supports muscular elongation in a dynamic and compliant way. Considering patients in the sub-acute phase after a neurological lesion, and possibly bedridden, the paper presents a mobiliser for the ankle joint, which is designed exploiting the SME to provide passive exercise to the paretic lower limb. Two different SMA-based applications in the field of neuroscience are then presented, a guide and a limb mobiliser specially designed to be compatible with diagnostic instrumentations that impose rigid constraints in terms of electromagnetic compatibility and noise distortion. Finally, the paper discusses possible uses of these materials in the treatment of movement disorders, such as dystonia or hyperkinesia, where their dynamic characteristics can be advantageous. PMID:26023790

  16. Tetanic fade following administration of nondepolarizing neuromuscular blocking drugs.

    PubMed

    Gibson, F M; Mirakhur, R K

    1989-06-01

    Fade in response to tetanic stimulation was studied following administration of atracurium 120 or 225 micrograms/kg, vecuronium 23 or 40 micrograms/kg, pancuronium 30 or 60 micrograms/kg, or d-tubocurarine 185 or 450 micrograms/kg. Ten patients received each dose and tetanic fade was measured at maximum block in the patients, who received the lower doses of the relaxants or at 10% recovery in those who received the higher doses. Fade during tetanic stimulation was generally similar in all the groups with the exception of the higher dose of pancuronium which showed a significantly greater fade in comparison with the higher doses of atracurium and d-tubocurarine. If fade in response to tetanic stimulation represents a prejunctional effect, the results from the present study suggest that neuromuscular blocking drugs cannot be differentiated with respect to their relative prejunctional effects by measurement of tetanic fade during established block after administration of clinically useful doses as used in the present study.

  17. Organelle pathology in metabolic neuromuscular disease: an overview.

    PubMed Central

    Becker, L E

    1990-01-01

    The spectrum of metabolic neuromuscular disorders is wide. Most inherited metabolic diseases are related to enzyme defects within lysosomes but recent advances emphasize abnormalities of mitochondria, peroxisomes and intermediate filaments. In this overview, organelle pathology is described in the context of both the clinical manifestations and the biochemical and/or molecular aspects of the disease. Among the many clinical presentations of mitochondrial disorders three emerge as distinctive entities: mitochondrial encephalopathy with lactic acidosis and stroke-like symptoms, mitochondrial encephalopathy with ragged-red fibers, and Kearns-Sayre syndrome. Peroxisomal disorders are associated with numerous biochemical defects, the most frequent of which are Zellweger's syndrome, neonatal adrenoleukodystrophy, and infantile Refsum's disease. Disorders of cytoskeletal proteins are associated with distinctive pathological accumulation of intermediate filaments but are without confirmed evidence of a biochemical defect. Understanding the role that organelle pathology plays in the pathogenesis of cellular disturbance or demise is essential to the elucidation of the pathogenesis of metabolic disorders. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. Fig. 9. Fig. 10. PMID:2407327

  18. Regional neuromuscular regulation within human rectus femoris muscle during gait.

    PubMed

    Watanabe, Kohei; Kouzaki, Motoki; Moritani, Toshio

    2014-11-01

    The spatial distribution pattern of neuromuscular activation within the human rectus femoris (RF) muscle was investigated during gait by multi-channel surface electromyography (surface EMG). Eleven healthy men walked on a treadmill with three gait speeds (4, 5, and 6 km/h) and gradients (0°, 12.5°, and 25°). The spatial distribution of surface EMG was tested by central locus activation (CLA), which is calculated from 2-D multi-channel surface EMG with 46 surface electrodes. For all conditions, CLA was around the middle regions during the swing-to-stance transition and moved in a proximal direction during the stance phase and stance-to-swing transition (p<0.05). CLA during the stance-to-swing transition and early swing phase significantly moved to proximal site with increasing gait speed (p<0.05). During the early stance and swing phases, with increasing grade, CLA significantly moved distally (p<0.05). These results suggest that the RF muscle is regionally activated during a gait cycle and is non-uniformly regulated longitudinally.

  19. Stabilization of human standing posture using functional neuromuscular stimulation.

    PubMed

    Soetanto, D; Kuo, C Y; Babic, D

    2001-12-01

    Functional neuromuscular stimulation (FNS)/functional electrical stimulation (FES) is a potential way to restore some functionality to the limbs of patients with spinal cord injury through direct/indirect stimulation of the motoneuron. One of the constraints for wider use of FNS on paraplegic patients is the lack of efficient control algorithm. Most of the published works on FNS/FES control are based on oversimplified models of human body dynamics. An innovative control strategy for stabilizing the standing posture of paraplegic patients is proposed here which is a combination of a proportional-plus-derivative controller for motions of the skeletal system and a control action prediction mechanism to produce musculotendon activation. The goal is to produce musculotendon torque which can approximate those demanded by the controller for the skeletal system. In computer simulations, using a detailed skeletal-musculotendon-muscle activation dynamics model of human body, this FNS/FES control approach can stabilize a paraplegic patient's standing posture with the minimum number of musculotendon groups. Also, it is found that this control strategy can maintain stability even in the presence of reasonable variations in the controller's musculotendon parameters.

  20. Neuromuscular synaptic function in mice lacking major subsets of gangliosides.

    PubMed

    Zitman, F M P; Todorov, B; Jacobs, B C; Verschuuren, J J; Furukawa, K; Furukawa, K; Willison, H J; Plomp, J J

    2008-10-28

    Gangliosides are a family of sialylated glycosphingolipids enriched in the outer leaflet of neuronal membranes, in particular at synapses. Therefore, they have been hypothesized to play a functional role in synaptic transmission. We have measured in detail the electrophysiological parameters of synaptic transmission at the neuromuscular junction (NMJ) ex vivo of a GD3-synthase knockout mouse, expressing only the O- and a-series gangliosides, as well as of a GM2/GD2-synthase*GD3-synthase double-knockout (dKO) mouse, lacking all gangliosides except GM3. No major synaptic deficits were found in either null-mutant. However, some extra degree of rundown of acetylcholine release at high intensity use was present at the dKO NMJ and a temperature-specific increase in acetylcholine release at 35 degrees C was observed in GD3-synthase knockout NMJs, compared with wild-type. These results indicate that synaptic transmission at the NMJ is not crucially dependent on the particular presence of most ganglioside family members and remains largely intact in the sole presence of GM3 ganglioside. Rather, presynaptic gangliosides appear to play a modulating role in temperature- and use-dependent fine-tuning of transmitter output. PMID:18801416

  1. Using factor analysis to identify neuromuscular synergies during treadmill walking

    NASA Technical Reports Server (NTRS)

    Merkle, L. A.; Layne, C. S.; Bloomberg, J. J.; Zhang, J. J.

    1998-01-01

    Neuroscientists are often interested in grouping variables to facilitate understanding of a particular phenomenon. Factor analysis is a powerful statistical technique that groups variables into conceptually meaningful clusters, but remains underutilized by neuroscience researchers presumably due to its complicated concepts and procedures. This paper illustrates an application of factor analysis to identify coordinated patterns of whole-body muscle activation during treadmill walking. Ten male subjects walked on a treadmill (6.4 km/h) for 20 s during which surface electromyographic (EMG) activity was obtained from the left side sternocleidomastoid, neck extensors, erector spinae, and right side biceps femoris, rectus femoris, tibialis anterior, and medial gastrocnemius. Factor analysis revealed 65% of the variance of seven muscles sampled aligned with two orthogonal factors, labeled 'transition control' and 'loading'. These two factors describe coordinated patterns of muscular activity across body segments that would not be evident by evaluating individual muscle patterns. The results show that factor analysis can be effectively used to explore relationships among muscle patterns across all body segments to increase understanding of the complex coordination necessary for smooth and efficient locomotion. We encourage neuroscientists to consider using factor analysis to identify coordinated patterns of neuromuscular activation that would be obscured using more traditional EMG analyses.

  2. Development of neuromuscular organization in the ctenophore Pleurobrachia bachei.

    PubMed

    Norekian, Tigran P; Moroz, Leonid L

    2016-01-01

    The phylogenetic position of the phylum Ctenophora and the nature of ctenphore nervous systems are highly debated topics in modern evolutionary biology. However, very little is known about the organization of ctenophore neural and muscular systems, and virtually nothing has been reported about their embryogenesis. Here we have characterized the neural and muscular development of the sea gooseberry, Pleurobrachia bachei, starting from the cleavage stages to posthatching larvae. Scanning electron microscopy and immunochemistry were used to describe the formation of the embryonic mouth, tentacles, combs, aboral organ, and putative sensory cells. The muscles started their specification at the end of the first day of Pleurobrachia development. In contrast, neurons appeared 2 days after myogenesis, just before the hatching of fully formed cydippid larvae. The first tubulin-immunoreactive neurons, a small group of four to six cells with neuronal processes, was initially recognized at the aboral pole during the third day of development. Surprisingly, this observed neurogenesis occurred after the emergence of distinct behavioral patterns in the embryos. Thus, the embryonic behavior associated with comb cilia beatings and initial muscle organization does not require morphologically defined neurons and their elongated neurites. This study provides the first description of neuromuscular development in the enigmatic ctenophores and establishes the foundation for future research using emerging genomic tools and resources. PMID:26105692

  3. A single-channel implantable microstimulator for functional neuromuscular stimulation.

    PubMed

    Ziaie, B; Nardin, M D; Coghlan, A R; Najafi, K

    1997-10-01

    This paper describes a single-channel implantable microstimulator for functional neuromuscular stimulation. This device measures 2 x 2 x 10 mm3 and can be inserted into paralyzed muscle groups by expulsion from a hypodermic needle. Power and data to the device are supplied from outside by RF telemetry using an amplitude-modulated 2-MHz RF carrier generated using a high-efficiency class-E transmitter. The transmitted signal carries a 5-b address which selects one of the 32 possible microstimulators. The selected device then delivers up to 2 microC of charge store in a tantalum chip capacitor for up to 200 microseconds (10 mA) into loads of < 800 omega through a high-current thin-film iridium-oxide (IrOx) electrode (approximately 0.3 mm2 in area). A bi-CMOS receiver circuitry is used to: generate two regulated voltage supplies (4.5 and 9 V), recover a 2-MHz clock from the carrier, demodulate the address code, and activate the output current delivery circuitry upon the reception of an external command. The overall power dissipation of the receiver circuitry is 45-55 mW. The implant is hermetically packaged using a custom-made glass capsule.

  4. Safe neuromuscular electrical stimulator designed for the elderly.

    PubMed

    Krenn, Matthias; Haller, Michael; Bijak, Manfred; Unger, Ewald; Hofer, Christian; Kern, Helmut; Mayr, Winfried

    2011-03-01

    A stimulator for neuromuscular electrical stimulation (NMES) was designed, especially suiting the requirements of elderly people with reduced cognitive abilities and diminished fine motor skills. The aging of skeletal muscle is characterized by a progressive decline in muscle mass, force, and condition. Muscle training with NMES reduces the degradation process. The discussed system is intended for evoked muscle training of the anterior and posterior thigh. The core of the stimulator is based on a microcontroller with two modular output stages. The system has two charge-balanced biphasic voltage-controlled stimulation channels. Additionally, the evoked myoelectric signal (M-wave) and the myokinematic signal (surface acceleration) are measured. A central controller unit allows using the stimulator as a stand-alone device. To set up the training sequences and to evaluate the compliance data, a personal computer is connected to the stimulator via a universal serial bus. To help elderly people handle the stimulator by themselves, the user interface is kept very simple. For safety reasons, the electrode impedance is monitored during stimulation. A comprehensive compliance management with included measurements of muscle activity and stimulation intensity enables a scientific use of the stimulator in clinical trials.

  5. Effects of two neuromuscular fatigue protocols on landing performance.

    PubMed

    James, C Roger; Scheuermann, Barry W; Smith, Michael P

    2010-08-01

    The purpose of the study was to investigate the effects of two fatigue protocols on landing performance. A repeated measures design was used to examine the effects of fatigue and fatigue protocol on neuromuscular and biomechanical performance variables. Ten volunteers performed non-fatigued and fatigued landings on two days using different fatigue protocols. Repeated maximum isometric squats were used to induce fatigue on day one. Sub-maximum cycling was used to induce fatigue on day two. Isometric squat maximum voluntary contraction (MVC) was measured before and after fatigued landings on each day. During the landings, ground reaction force (GRF), knee kinematics, and electromyographic (EMG) data were recorded. Isometric MVC, GRF peaks, loading rates, impulse, knee flexion at contact, range of motion, max angular velocity, and EMG root mean square (RMS) values were compared pre- and post-fatiguing exercise and between fatigue protocols using repeated ANOVA. Fatigue decreased MVC strength (p0.05), GRF second peak, and initial impulse (p0.01), but increased quadriceps medium latency stretch reflex EMG activity (p0.012). Knee flexion at contact was 5.2 degrees greater (p0.05) during fatigued landings following the squat exercise compared to cycling. Several variables exhibited non-significant but large effect sizes when comparing the effects of fatigue and fatigue protocol. In conclusion, fatigue alters landing performance and different fatigue protocols result in different performance changes.

  6. Neuromuscular disorders: genes, genetic counseling and therapeutic trials

    PubMed Central

    Zatz, Mayana; Passos-Bueno, Maria Rita; Vainzof, Mariz

    2016-01-01

    Abstract Neuromuscular disorders (NMD) are a heterogeneous group of genetic conditions, with autosomal dominant, recessive, or X-linked inheritance. They are characterized by progressive muscle degeneration and weakness. Here, we are presenting our major contributions to the field during the past 30 years. We have mapped and identified several novel genes responsible for NMD. Genotype-phenotype correlations studies enhanced our comprehension on the effect of gene mutations on related proteins and their impact on clinical findings. The search for modifier factors allowed the identification of a novel "protective"; variant which may have important implication on therapeutic developments. Molecular diagnosis was introduced in the 1980s and new technologies have been incorporated since then. Next generation sequencing greatly improved our capacity to identify disease-causing mutations with important benefits for research and prevention through genetic counseling of patients' families. Stem cells researches, from and for patients, have been used as tools to study human genetic diseases mechanisms and for therapies development. The clinical effect of preclinical trials in mice and canine models for muscular dystrophies are under investigation. Finally, the integration of our researches and genetic services with our post-graduation program resulted in a significant output of new geneticists, spreading out this expertise to our large country. PMID:27575431

  7. Frontotemporal dementia: a bridge between dementia and neuromuscular disease

    PubMed Central

    Ng, Adeline SL; Rademakers, Rosa; Miller, BL

    2015-01-01

    The concept that frontotemporal dementia (FTD) is a purely “cortical” dementia has largely been refuted by the recognition of its close association with motor neuron disease, and the identification of transactive response DNA-binding protein 43 (TDP-43) as a major pathological substrate underlying both diseases. Genetic findings have transformed this field and revealed connections between disorders that were previous thought clinically unrelated. The discovery of the C9ORF72 locus as responsible for majority of hereditary FTD, ALS and FTD-ALS cases and the understanding that repeat-containing RNA plays a crucial role in pathogenesis of both disorders has paved the way for development of potential biomarkers and therapeutic targets for these devastating diseases. In this review, we summarize the historical aspects leading up to our current understanding of the genetic, clinical and neuropathological overlap between FTD and ALS, and include brief discussions on chronic traumatic encephalopathy (CTE) given its association with TDP-43 pathology, increased dementia risk and reports of ALS in CTE patients. Additionally we describe other genetic associations between dementia and neuromuscular disease, such as inclusion body myositis with Paget’s disease and frontotemporal dementia (IBMPFD). PMID:25557955

  8. Neuromuscular disorders: genes, genetic counseling and therapeutic trials.

    PubMed

    Zatz, Mayana; Passos-Bueno, Maria Rita; Vainzof, Mariz

    2016-01-01

    Neuromuscular disorders (NMD) are a heterogeneous group of genetic conditions, with autosomal dominant, recessive, or X-linked inheritance. They are characterized by progressive muscle degeneration and weakness. Here, we are presenting our major contributions to the field during the past 30 years. We have mapped and identified several novel genes responsible for NMD. Genotype-phenotype correlations studies enhanced our comprehension on the effect of gene mutations on related proteins and their impact on clinical findings. The search for modifier factors allowed the identification of a novel "protective"; variant which may have important implication on therapeutic developments. Molecular diagnosis was introduced in the 1980s and new technologies have been incorporated since then. Next generation sequencing greatly improved our capacity to identify disease-causing mutations with important benefits for research and prevention through genetic counseling of patients' families. Stem cells researches, from and for patients, have been used as tools to study human genetic diseases mechanisms and for therapies development. The clinical effect of preclinical trials in mice and canine models for muscular dystrophies are under investigation. Finally, the integration of our researches and genetic services with our post-graduation program resulted in a significant output of new geneticists, spreading out this expertise to our large country. PMID:27575431

  9. Safe neuromuscular electrical stimulator designed for the elderly.

    PubMed

    Krenn, Matthias; Haller, Michael; Bijak, Manfred; Unger, Ewald; Hofer, Christian; Kern, Helmut; Mayr, Winfried

    2011-03-01

    A stimulator for neuromuscular electrical stimulation (NMES) was designed, especially suiting the requirements of elderly people with reduced cognitive abilities and diminished fine motor skills. The aging of skeletal muscle is characterized by a progressive decline in muscle mass, force, and condition. Muscle training with NMES reduces the degradation process. The discussed system is intended for evoked muscle training of the anterior and posterior thigh. The core of the stimulator is based on a microcontroller with two modular output stages. The system has two charge-balanced biphasic voltage-controlled stimulation channels. Additionally, the evoked myoelectric signal (M-wave) and the myokinematic signal (surface acceleration) are measured. A central controller unit allows using the stimulator as a stand-alone device. To set up the training sequences and to evaluate the compliance data, a personal computer is connected to the stimulator via a universal serial bus. To help elderly people handle the stimulator by themselves, the user interface is kept very simple. For safety reasons, the electrode impedance is monitored during stimulation. A comprehensive compliance management with included measurements of muscle activity and stimulation intensity enables a scientific use of the stimulator in clinical trials. PMID:21401669

  10. [Critical study of radiculomedullary and neuromuscular complications of ankylosing spondylitis].

    PubMed

    Serratrice, G; Acquaviva, P; Pouget, J; Guerra, L

    1987-03-01

    Medullo-radicular and neuro-muscular involvements of ankylosing spondylarthritis, often reported in an analytic fashion in the literature, deserve to be the subject of a critical study. Various neurological manifestations secondary to exceptional atlo-occipital and sometimes axis-atlas subluxations and medullary lesions as well as syndromes of the cauda equina. The medullary lesions have an epidural origin (3 cases in the literature, 2 cases from the authors) or are secondary to a spondylodiscitis (4 cases in the literature) or secondary to both (1 case reported by the authors). As for syndromes of the cauda equina the authors report 3 cases to be added to the 55 published previously. It concerns always old spondylarthritis. The lesions combine posterior diverticula and lesions of the lamina. The treatment is usually ineffective. A special case is represented by forms with trophic disorders. More debatable are the radicular lesions, which, except for intercostal pain, should be linked to local pain. Electromyographic abnormalities are of no significance. Alterations of the paravertebral muscles viewed on the scanner X have, for now, an uncertain significance. Finally, various associations, without significance such as multiple sclerosis, diffuse muscular lesions and the classic spondylotic pseudo-tabes, should be rejected.

  11. [Balters' appliance and its action on the neuromuscular system].

    PubMed

    Travesi Gomez, J

    1992-01-01

    Bionator created by BALTERS comes directly from activator but is smaller allowing its use during day and night to achieve mainly: lip closure, tongue in contact with soft palate, make oral area bigger improving its functionality, get a better maxillary relationship making mandible longer and improve tongue position. The principle that a new neuromuscular pattern conducted by appliance drives to development of a new morphologic pattern. Its activity on neuromusculature is neither well documented nor studied. Actually it is admitted that craniomandibular muscles contraction depends on neural pattern of this muscles during movement. This pattern is modified by continuous sensorial feed-back coming from dentition, T.M.J., and muscular and tendinal length and strength receptors. Clinical studies on mandibular advancement, show that occlusion alteration in sagittal mandibular reposition drives to spontaneous activity changes in muscles and to changes in electromyographic rest of certain muscles like the temporal. In some cases it is founded an increase in molar bite due to anterior mandibular reposition force. Clinical studies on mandibular advancement show changes on mandibular muscles spontaneous activity and possibility of modifications of E.M.G. rest level of temporalis. In some cases an increasing of bite force on first molars is founded. Electromyographic changes appear in children early, and produce a new functional position that changes morphology. Feed-back information comes from periodontal and muscular receptors. Patients treated show lip closure without strength, better tongue positioning and swallowing, and lower tension on suprahyoid muscles.

  12. Development of neuromuscular organization in the ctenophore Pleurobrachia bachei.

    PubMed

    Norekian, Tigran P; Moroz, Leonid L

    2016-01-01

    The phylogenetic position of the phylum Ctenophora and the nature of ctenphore nervous systems are highly debated topics in modern evolutionary biology. However, very little is known about the organization of ctenophore neural and muscular systems, and virtually nothing has been reported about their embryogenesis. Here we have characterized the neural and muscular development of the sea gooseberry, Pleurobrachia bachei, starting from the cleavage stages to posthatching larvae. Scanning electron microscopy and immunochemistry were used to describe the formation of the embryonic mouth, tentacles, combs, aboral organ, and putative sensory cells. The muscles started their specification at the end of the first day of Pleurobrachia development. In contrast, neurons appeared 2 days after myogenesis, just before the hatching of fully formed cydippid larvae. The first tubulin-immunoreactive neurons, a small group of four to six cells with neuronal processes, was initially recognized at the aboral pole during the third day of development. Surprisingly, this observed neurogenesis occurred after the emergence of distinct behavioral patterns in the embryos. Thus, the embryonic behavior associated with comb cilia beatings and initial muscle organization does not require morphologically defined neurons and their elongated neurites. This study provides the first description of neuromuscular development in the enigmatic ctenophores and establishes the foundation for future research using emerging genomic tools and resources.

  13. Active zones of mammalian neuromuscular junctions: formation, density, and aging

    PubMed Central

    Nishimune, Hiroshi

    2012-01-01

    Presynaptic active zones are synaptic vesicle release sites that playessential roles in the function and pathology of mammalian neuromuscular junctions (NMJs). The molecular mechanisms of active zone organization utilize presynaptic voltage-dependent calcium channels (VDCCs) in NMJs as scaffolding proteins. VDCCs interact extracellularly with the muscle-derived synapse organizer, laminin β2, and interact intracellularly with active zone-specific proteins, such as Bassoon, CAST/Erc2/ELKS2alpha, ELKS, Piccolo, and RIMs. These molecular mechanisms are supported by studies in P/Q- and N-type VDCCs double-knockout mice, and they are consistent with the pathological conditions of Lambert-Eaton myasthenic syndrome and Pierson syndrome, which are caused by autoantibodies against VDCCs or by a laminin β2 mutation. During normal postnatal maturation, NMJs maintain the density of active zones, while NMJs triple their size. However, active zones become impaired during aging. Propitiously, muscle exercise ameliorates the active zone impairment in aged NMJs, which suggests the potential for therapeutic strategies. PMID:23252894

  14. Degeneration of Neuromuscular Junction in Age and Dystrophy

    PubMed Central

    Rudolf, Rüdiger; Khan, Muzamil Majid; Labeit, Siegfried; Deschenes, Michael R.

    2014-01-01

    Functional denervation is a hallmark of aging sarcopenia as well as of muscular dystrophy. It is thought to be a major factor reducing skeletal muscle mass, particularly in the case of sarcopenia. Neuromuscular junctions (NMJs) serve as the interface between the nervous and skeletal muscular systems, and thus they may receive pathophysiological input of both pre- and post-synaptic origin. Consequently, NMJs are good indicators of motor health on a systemic level. Indeed, upon sarcopenia and dystrophy, NMJs morphologically deteriorate and exhibit altered characteristics of primary signaling molecules, such as nicotinic acetylcholine receptor and agrin. Since a remarkable reversibility of these changes can be observed by exercise, there is significant interest in understanding the molecular mechanisms underlying synaptic deterioration upon aging and dystrophy and how synapses are reset by the aforementioned treatments. Here, we review the literature that describes the phenomena observed at the NMJ in sarcopenic and dystrophic muscle as well as to how these alterations can be reversed and to what extent. In a second part, the current information about molecular machineries underlying these processes is reported. PMID:24904412

  15. Level of independence of motor unit properties from neuromuscular activity.

    PubMed

    Pierotti, D J; Roy, R R; Hodgson, J A; Edgerton, V R

    1994-11-01

    Neuromuscular activity was eliminated in the tibialis anterior muscle of adult cats for 6 months by spinal isolation (SI), i.e., complete spinal cord transections at T-12-13 and at L-7-S-1, plus bilateral dorsal rhizotomy between the two transection sites. One motor unit from each muscle was isolated using ventral root teasing procedures and physiologically tested. The fibers belonging to each motor unit were visualized in PAS-stained sections by the loss of glycogen following prolonged repetitive stimulation. Qualitatively, the normal enzymatic interrelationships among fibers identified by myosin heavy chain composition were unchanged by SI. Generally, each motor unit from SI cats were of a single myosin immunohistochemical type. The same physiological motor unit types that typify control muscles were found in SI cats. In SI compared to control cats, there was approximately a 10% increase in the number of muscle fibers expressing fast myosin. Mean fiber activity levels of ATPase and SDH for a given fiber type (based on MHC antibody reactions) decreased by approximately 10% and 25%, whereas GPD activity increased approximately 35%. It is concluded that differential levels or patterns of activity are not essential to maintain the range of histochemical and physiological motor unit types found in the tibialis anterior of normal adult cats.

  16. Applications of shape memory alloys for neurology and neuromuscular rehabilitation.

    PubMed

    Pittaccio, Simone; Garavaglia, Lorenzo; Ceriotti, Carlo; Passaretti, Francesca

    2015-01-01

    Shape memory alloys (SMAs) are a very promising class of metallic materials that display interesting nonlinear properties, such as pseudoelasticity (PE), shape memory effect (SME) and damping capacity, due to high mechanical hysteresis and internal friction. Our group has applied SMA in the field of neuromuscular rehabilitation, designing some new devices based on the mentioned SMA properties: in particular, a new type of orthosis for spastic limb repositioning, which allows residual voluntary movement of the impaired limb and has no predetermined final target position, but follows and supports muscular elongation in a dynamic and compliant way. Considering patients in the sub-acute phase after a neurological lesion, and possibly bedridden, the paper presents a mobiliser for the ankle joint, which is designed exploiting the SME to provide passive exercise to the paretic lower limb. Two different SMA-based applications in the field of neuroscience are then presented, a guide and a limb mobiliser specially designed to be compatible with diagnostic instrumentations that impose rigid constraints in terms of electromagnetic compatibility and noise distortion. Finally, the paper discusses possible uses of these materials in the treatment of movement disorders, such as dystonia or hyperkinesia, where their dynamic characteristics can be advantageous.

  17. Pseudoephedrine and circadian rhythm interaction on neuromuscular performance.

    PubMed

    Pallarés, J G; López-Samanes, Á; Fernández-Elías, V E; Aguado-Jiménez, R; Ortega, J F; Gómez, C; Ventura, R; Segura, J; Mora-Rodríguez, R

    2015-12-01

    This study analyzed the effects of pseudoephedrine (PSE) provided at different time of day on neuromuscular performance, side effects, and violation of the current doping cut-off threshold [World Anti-Doping Agency (WADA)]. Nine resistance-trained males carried out bench press and full squat exercises against four incremental loads (25%, 50%, 75%, and 90% one repetition maximum [1RM]), in a randomized, double-blind, cross-over design. Participants ingested either 180 mg of PSE (supra-therapeutic dose) or placebo in the morning (7:00 h; AM(PLAC) and AM(PSE)) and in the afternoon (17:00 h; PM(PLAC) and PM(PSE)). PSE enhanced muscle contraction velocity against 25% and 50% 1RM loads, only when it was ingested in the mornings, and only in the full squat exercise (4.4-8.7%; P < 0.05). PSE ingestion raised urine and plasma PSE concentrations (P < 0.05) regardless of time of day; however, cathine only increased in the urine samples. PSE ingestion resulted in positive tests occurring in 11% of samples, and it rose some adverse side effects such us tachycardia and heart palpitations. Ingestion of a single dose of 180 mg of PSE results in enhanced lower body muscle contraction velocity against low and moderate loads only in the mornings. These mild performance improvements are accompanied by undesirable side effects and an 11% risk of surpassing the doping threshold.

  18. Neuromuscular strategies contributing to faster multidirectional agility performance.

    PubMed

    Spiteri, Tania; Newton, Robert U; Nimphius, Sophia

    2015-08-01

    The aim of this study was to first determine differences in neuromuscular strategy between a faster and slower agility performance, and second compare differences in muscle activation strategy employed when performing two closely executed agility movements. Participants recruited from an elite female basketball team completed an ultrasound to determine quadriceps muscle-cross sectional area; reactive isometric mid-thigh pull to determine the rate of muscle activation, rate of force development, pre-motor time and motor time; and multidirectional agility tests completing two directional changes in response to a visual stimulus. Peak and average relative muscle activation of the rectus femoris, vastus medialis, vastus lateralis, biceps femoris, semitendinosus and gastrocnemius were measured 100ms prior to heel strike (pre-heel strike) and across stance phase for both directional changes. Faster agility performance was characterized by greater pre-heel strike muscle activity and greater anterior muscle activation during stance phase resulting in greater hip and knee extension increasing propulsive impulse. Differences between directional changes appear to result from processing speed, where a greater delay in refractory times during the second directional change resulted in greater anterior muscle activation, decelerating the body while movement direction was determined.

  19. Corrective Neuromuscular Approach to the Treatment of Iliotibial Band Friction Syndrome: A Case Report

    PubMed Central

    Pettitt, Robert; Dolski, Angela

    2000-01-01

    Objective: To describe the evaluation and treatment process for inappropriate functional patterns of neuromuscular activity within the scope of an iliotibial band friction syndrome protocol. Background: Runners with iliotibial band friction syndrome are frequently fitted with orthotic devices to restrict excessive midfoot or rearfoot, or both, motions during the stance phase. These devices may fail to yield favorable results when underlying neuromuscular factors are associated with functional iliotibial band tightening. Differential Diagnosis: Distal biceps femoris tendinitis, popliteal tendinitis, lateral meniscus lesion. Treatment: The athlete's physical examination revealed several patterns of inappropriate neuromuscular activity attributed partly to the prolonged daily wear of beach-type sandals. Modifications of casual footwear and a temporary reduction in training volume were recommended initially to prevent exacerbation of the athlete's condition. Stretching, massage, and soft tissue mobilization were administered in accordance with the athlete's specific needs. The protocol included progressions of nonweightbearing and weightbearing therapeutic exercises. Neuromuscular electric stimulation was incorporated into the protocol to re-educate the role of the first ray within the stance phase of the athlete's walking gait. Uniqueness: Upon stationary examination, this athlete presented with normal lumbar and lower extremity postures. Gait analysis, however, revealed inappropriate dorsiflexion of the great toe during ambulation. Further, the athlete's performances on a series of tests to assess neuromuscular function were substandard. This athlete's response to previous treatment and unique physical findings required a corrective neuromuscular approach that deviates from iliotibial band friction syndrome protocols advocating the use of orthotics. Conclusions: While the role of any single treatment in the athlete's recovery remains unknown, it seems that a

  20. Targeting of the ETS Factor Gabpα Disrupts Neuromuscular Junction Synaptic Function▿ §

    PubMed Central

    O'Leary, Debra A.; Noakes, Peter G.; Lavidis, Nick A.; Kola, Ismail; Hertzog, Paul J.; Ristevski, Sika

    2007-01-01

    The GA-binding protein (GABP) transcription factor has been shown in vitro to regulate the expression of the neuromuscular proteins utrophin, acetylcholine esterase, and acetylcholine receptor subunits δ and ɛ through the N-box promoter motif (5′-CCGGAA-3′), but its in vivo function remains unknown. A single point mutation within the N-box of the gene encoding the acetylcholine receptor ɛ subunit has been identified in several patients suffering from postsynaptic congenital myasthenic syndrome, implicating the GA-binding protein in neuromuscular function and disease. Since conventional gene targeting results in an embryonic-lethal phenotype, we used conditional targeting to investigate the role of GABPα in neuromuscular junction and skeletal muscle development. The diaphragm and soleus muscles from mutant mice display alterations in morphology and distribution of acetylcholine receptor clusters at the neuromuscular junction and neurotransmission properties consistent with reduced receptor function. Furthermore, we confirmed decreased expression of the acetylcholine receptor ɛ subunit and increased expression of the γ subunit in skeletal muscle tissues. Therefore, the GABP transcription factor aids in the structural formation and function of neuromuscular junctions by regulating the expression of postsynaptic genes. PMID:17325042

  1. A Dutch guideline for the treatment of scoliosis in neuromuscular disorders

    PubMed Central

    Mullender, MG; Blom, NA; De Kleuver, M; Fock, JM; Hitters, WMGC; Horemans, AMC; Kalkman, CJ; Pruijs, JEH; Timmer, RR; Titarsolej, PJ; Van Haasteren, NC; Jager, MJ Van Tol-de; Van Vught, AJ; Van Royen, BJ

    2008-01-01

    Background Children with neuromuscular disorders with a progressive muscle weakness such as Duchenne Muscular Dystrophy and Spinal Muscular Atrophy frequently develop a progressive scoliosis. A severe scoliosis compromises respiratory function and makes sitting more difficult. Spinal surgery is considered the primary treatment option for correcting severe scoliosis in neuromuscular disorders. Surgery in this population requires a multidisciplinary approach, careful planning, dedicated surgical procedures, and specialized after care. Methods The guideline is based on scientific evidence and expert opinions. A multidisciplinary working group representing experts from all relevant specialties performed the research. A literature search was conducted to collect scientific evidence in answer to specific questions posed by the working group. Literature was classified according to the level of evidence. Results For most aspects of the treatment scientific evidence is scarce and only low level cohort studies were found. Nevertheless, a high degree of consensus was reached about the management of patients with scoliosis in neuromuscular disorders. This was translated into a set of recommendations, which are now officially accepted as a general guideline in the Netherlands. Conclusion In order to optimize the treatment for scoliosis in neuromuscular disorders a Dutch guideline has been composed. This evidence-based, multidisciplinary guideline addresses conservative treatment, the preoperative, perioperative, and postoperative care of scoliosis in neuromuscular disorders. PMID:18822133

  2. Gait and Neuromuscular Asymmetries after Acute ACL Rupture

    PubMed Central

    Gardinier, Emily S.; Manal, Kurt; Buchanan, Thomas S.; Snyder-Mackler, Lynn

    2012-01-01

    The decreased internal knee extensor moment is a significant gait asymmetry among patients with anterior cruciate ligament (ACL) deficiency, yet the muscular strategy driving this altered moment for the injured limb is unclear. Purpose To determine whether patients with ACL deficiency and characteristic knee instability would demonstrate normal extensor and increased flexor muscle force to generate a decreased internal extensor moment (i.e. employ a hamstring facilitation strategy). Methods Gait analysis was performed on 31 athletes with acute ACL rupture who exhibited characteristic knee instability after injury. Peak internal knee extensor moment was calculated using inverse dynamics and muscle forces were estimated using an EMG-driven modeling approach. Comparisons were made between the injured and contralateral limbs. Results As expected, patients demonstrated decreased peak knee flexion (p=0.028) and internal knee extensor moment (p=0.0004) for their injured limb, but exhibited neither an isolated decrease in extensor force (quadriceps avoidance), nor an isolated increase in flexor force (hamstring facilitation) at peak knee moment. Instead, they exhibited decreased muscle force from both flexor (p=0.0001) and extensor (p=0.0103) groups. This strategy of decreased muscle force may be explained in part by muscle weakness which frequently accompanies ACL injury, or by apprehension, low confidence and fear of further injury. Conclusions This is the first study to estimate muscle forces in the ACL-deficient knee using an EMG-driven approach. These results affirm the existence of neuromuscular asymmetries in the individuals with ACL deficiency and characteristic knee instability. PMID:22330021

  3. Kinetics of neuromuscular changes during low-frequency electrical stimulation.

    PubMed

    Papaiordanidou, Maria; Guiraud, David; Varray, Alain

    2010-01-01

    The purpose of the study was to examine the time course of neuromuscular fatigue components during a low-frequency electrostimulation (ES) session. Three bouts of 17 trains of stimulation at 30 HZ (4 s on, 6 s off) were used to electrically induce fatigue in the plantar flexor muscles. Before and after every 17-train bout, torque, electromyographic activity [expressed as root mean square (RMS) and median frequency (MF) values], evoked potentials (M-wave and H-reflex), and the level of voluntary activation (LOA, using twitch interpolation technique) were assessed. Torque during maximal voluntary contraction decreased significantly from the very first stimulation bout (-6.6 +/- 1.11%, P < 0.001) and throughout the session (-10.32 +/- 1.68% and -11.53 +/- 1.27%, for the second and third bouts, respectively). The LOA and RMS/Mmax values were significantly decreased during the ES session (-2.9 +/- 1.07% and -17.5 +/- 6.14%, P < 0.01 and P< 0.001, respectively, at the end of the protocol), while MF showed no changes. The Hmax/Mmax ratio and Mmax were not significantly modified during the session. All twitch parameters were significantly potentiated after the first bout and throughout the session (P < 0.001). The maximal torque decrease was evident from the early phase of a low-frequency ES protocol, with no concomitant inhibition of motoneuron excitability or depression of muscle contractile properties. These results are consistent with an early failure of the central drive to the muscle. PMID:19882645

  4. Are neuromuscular blocking agents being misused in laboratory pigs?

    PubMed

    Bradbury, A G; Clutton, R E

    2016-04-01

    The literature (2012-4) describing experimental pig surgery was reviewed to estimate the extent to which neuromuscular block (NMB) is used, to examine methods for ensuring unconsciousness, and to identify the rationale for use of NMB and establish the anaesthetist's training. In the first stage of a two-stage review, NMB use was estimated using Web of Knowledge to identify articles describing NMB during pig surgeries. In the second stage, PubMed and Google Scholar were used to increase the number of articles for determining measures taken to prevent accidental awareness during general anaesthesia (AAGA). The corresponding authors of screened articles were emailed four times to establish the reason for using NMB and the anaesthetists' backgrounds (medical, veterinary, or technical). The first search revealed NMB use in 80 of 411 (20%) studies. Of the 153 articles analysed in the second stage, two described strategies to reduce AAGA. Some (6%) papers did not provide information on anaesthetic doses; citations supporting anaesthetic efficacy were found in only 13. Five of 69 papers using inhalation agents measured end-tidal anaesthetic concentrations based on human, not porcine, minimal alveolar concentrations. The methods in 13% of articles reporting anaesthetic depth assessment were incomplete or questionable, or both; four described using somatic motor reflexes. Corresponding authors of 121 articles reported that the principal reason for NMB was improved 'surgical visualization' (26%). Medical or veterinary anaesthetists supervised anaesthesia in 70% of studies; non-anaesthetists provided NMB, unsupervised, in 23. Nine respondents prioritized experimental expediency over pig welfare. In laboratory pig studies, AAGA may be prevalent; reported details of its attempted prevention are woefully inadequate.

  5. Wnt4 Participates in the Formation of Vertebrate Neuromuscular Junction

    PubMed Central

    Strochlic, Laure; Falk, Julien; Goillot, Evelyne; Sigoillot, Séverine; Bourgeois, Francine; Delers, Perrine; Rouvière, Jérôme; Swain, Amanda; Castellani, Valérie; Schaeffer, Laurent; Legay, Claire

    2012-01-01

    Neuromuscular junction (NMJ) formation requires the highly coordinated communication of several reciprocal signaling processes between motoneurons and their muscle targets. Identification of the early, spatially restricted cues in target recognition at the NMJ is still poorly documented, especially in mammals. Wnt signaling is one of the key pathways regulating synaptic connectivity. Here, we report that Wnt4 contributes to the formation of vertebrate NMJ in vivo. Results from a microarray screen and quantitative RT-PCR demonstrate that Wnt4 expression is regulated during muscle cell differentiation in vitro and muscle development in vivo, being highly expressed when the first synaptic contacts are formed and subsequently downregulated. Analysis of the mouse Wnt4−/− NMJ phenotype reveals profound innervation defects including motor axons overgrowing and bypassing AChR aggregates with 30% of AChR clusters being unapposed by nerve terminals. In addition, loss of Wnt4 function results in a 35% decrease of the number of prepatterned AChR clusters while Wnt4 overexpression in cultured myotubes increases the number of AChR clusters demonstrating that Wnt4 directly affects postsynaptic differentiation. In contrast, muscle structure and the localization of several synaptic proteins including acetylcholinesterase, MuSK and rapsyn are not perturbed in the Wnt4 mutant. Finally, we identify MuSK as a Wnt4 receptor. Wnt4 not only interacts with MuSK ectodomain but also mediates MuSK activation. Taken together our data reveal a new role for Wnt4 in mammalian NMJ formation that could be mediated by MuSK, a key receptor in synaptogenesis. PMID:22253844

  6. Effects of several antibiotics on the neuromuscular junction: Part II.

    PubMed

    Yamada, S; Kuno, Y; Iwanaga, H

    1986-04-01

    The effects of various kinds of antibiotics including tetracycline (TC), chloramphenicol (CP), sodium cephalothin (CET), sodium cefazolin (CEZ), colistin sulfate (CL), colistin sodium methanesulfonate (CL-M), bacitracin (BC), gramicidin HCl (GR), rifampicin sulfate (RFP) and lincomycin (LCM), on the neuromuscular junction (NMJ) were studied by in vitro and in vivo experiments. In in vitro experiments, CL and LCM exhibited a blocking effect on the NMJ in rat phrenic nerve diaphragm preparations, and GR caused a marked increase in muscle contraction. This effect was not affected by administration of eserine or CaCl2. In in vitro experiments with frog sciatica nerve and musculus sartorius preparations, CL and GR induced the appearance of endplate potentials, suggesting blockade of the NMJ. No blocking effect of other antibiotics was observed. In in vitro experiments with the preparations from Rana catesbiana frogs, TC and LCM induced a decrease in the frequency of miniature endplate potentials. In in vivo experiments with rabbit musculus tibialis anterior preparations, CL, TC and LCM exerted a blocking effect soon after administration, but GR and RFP had a late blocking effect. CL, GR, BC and RFP were found not to compete with eserine or CaCl2 in terms of the blocking effect on the NMJ. From the fact that TC did not compete with eserine but did compete with CaCl2 and with KCl as blockers at the NMJ, this blocking effect of TC seems to be due to inhibition of release of acetylcholine (ACh). The fact that LCM competes with eserine indicates that this antibiotic has the same type of action as curare on ACh receptors of the NMJ.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3486835

  7. Neuromuscular consequences of an extreme mountain ultra-marathon.

    PubMed

    Millet, Guillaume Y; Tomazin, Katja; Verges, Samuel; Vincent, Christopher; Bonnefoy, Régis; Boisson, Renée-Claude; Gergelé, Laurent; Féasson, Léonard; Martin, Vincent

    2011-01-01

    We investigated the physiological consequences of one of the most extreme exercises realized by humans in race conditions: a 166-km mountain ultra-marathon (MUM) with 9500 m of positive and negative elevation change. For this purpose, (i) the fatigue induced by the MUM and (ii) the recovery processes over two weeks were assessed. Evaluation of neuromuscular function (NMF) and blood markers of muscle damage and inflammation were performed before and immediately following (n = 22), and 2, 5, 9 and 16 days after the MUM (n = 11) in experienced ultra-marathon runners. Large maximal voluntary contraction decreases occurred after MUM (-35% [95% CI: -28 to -42%] and -39% [95% CI: -32 to -46%] for KE and PF, respectively), with alteration of maximal voluntary activation, mainly for KE (-19% [95% CI: -7 to -32%]). Significant modifications in markers of muscle damage and inflammation were observed after the MUM as suggested by the large changes in creatine kinase (from 144 ± 94 to 13,633 ± 12,626 UI L(-1)), myoglobin (from 32 ± 22 to 1,432 ± 1,209 µg L(-1)), and C-Reactive Protein (from <2.0 to 37.7 ± 26.5 mg L(-1)). Moderate to large reductions in maximal compound muscle action potential amplitude, high-frequency doublet force, and low frequency fatigue (index of excitation-contraction coupling alteration) were also observed for both muscle groups. Sixteen days after MUM, NMF had returned to initial values, with most of the recovery process occurring within 9 days of the race. These findings suggest that the large alterations in NMF after an ultra-marathon race are multi-factorial, including failure of excitation-contraction coupling, which has never been described after prolonged running. It is also concluded that as early as two weeks after such an extreme running exercise, maximal force capacities have returned to baseline.

  8. Effects of hindlimb unloading on neuromuscular development of neonatal rats

    NASA Technical Reports Server (NTRS)

    Huckstorf, B. L.; Slocum, G. R.; Bain, J. L.; Reiser, P. M.; Sedlak, F. R.; Wong-Riley, M. T.; Riley, D. A.

    2000-01-01

    We hypothesized that hindlimb suspension unloading of 8-day-old neonatal rats would disrupt the normal development of muscle fiber types and the motor innervation of the antigravity (weightbearing) soleus muscles but not extensor digitorum longus (EDL) muscles. Five rats were suspended 4.5 h and returned 1.5 h to the dam for nursing on a 24 h cycle for 9 days. To control for isolation from the dam, the remaining five littermates were removed on the same schedule but not suspended. Another litter of 10 rats housed in the same room provided a vivarium control. Fibers were typed by myofibrillar ATPase histochemistry and immunostaining for embryonic, slow, fast IIA and fast IIB isomyosins. The percentage of multiple innervation and the complexity of singly-innervated motor terminal endings were assessed in silver/cholinesterase stained sections. Unique to the soleus, unloading accelerated production of fast IIA myosin, delayed expression of slow myosin and retarded increases in standardized muscle weight and fiber size. Loss of multiple innervation was not delayed. However, fewer than normal motor nerve endings achieved complexity. Suspended rats continued unloaded hindlimb movements. These findings suggest that motor neurons resolve multiple innervation through nerve impulse activity, whereas the postsynaptic element (muscle fiber) controls endplate size, which regulates motor terminal arborization. Unexpectedly, in the EDL of unloaded rats, transition from embryonic to fast myosin expression was retarded. Suspension-related foot drop, which stretches and chronically loads EDL, may have prevented fast fiber differentiation. These results demonstrate that neuromuscular development of both weightbearing and non-weightbearing muscles in rats is dependent upon and modulated by hindlimb loading.

  9. Local identifiability and sensitivity analysis of neuromuscular blockade and depth of hypnosis models.

    PubMed

    Silva, M M; Lemos, J M; Coito, A; Costa, B A; Wigren, T; Mendonça, T

    2014-01-01

    This paper addresses the local identifiability and sensitivity properties of two classes of Wiener models for the neuromuscular blockade and depth of hypnosis, when drug dose profiles like the ones commonly administered in the clinical practice are used as model inputs. The local parameter identifiability was assessed based on the singular value decomposition of the normalized sensitivity matrix. For the given input signal excitation, the results show an over-parameterization of the standard pharmacokinetic/pharmacodynamic models. The same identifiability assessment was performed on recently proposed minimally parameterized parsimonious models for both the neuromuscular blockade and the depth of hypnosis. The results show that the majority of the model parameters are identifiable from the available input-output data. This indicates that any identification strategy based on the minimally parameterized parsimonious Wiener models for the neuromuscular blockade and for the depth of hypnosis is likely to be more successful than if standard models are used.

  10. Analgesia, sedation, and neuromuscular blockade during targeted temperature management after cardiac arrest.

    PubMed

    Riker, Richard R; Gagnon, David J; May, Teresa; Seder, David B; Fraser, Gilles L

    2015-12-01

    The approach to sedation, analgesia, and neuromuscular blockade during targeted temperature management (TTM) remains largely unstudied, forcing clinicians to adapt previous research from other patient environments. During TTM, very little data guide drug selection, doses, and specific therapeutic goals. Sedation should be deep enough to prevent awareness during neuromuscular blockade, but titration is complex as metabolism and clearance are delayed for almost all drugs during hypothermia. Deeper sedation is associated with prolonged intensive care unit (ICU) and ventilator therapy, increased delirium and infection, and delayed wakening which can confound early critical neurological assessments, potentially resulting in erroneous prognostication and inappropriate withdrawal of life support. We review the potential therapeutic goals for sedation, analgesia, and neuromuscular blockade during TTM; the adverse events associated with that treatment; data suggesting that TTM and organ dysfunction impair drug metabolism; and controversies and potential benefits of specific monitoring. We also highlight the areas needing better research to guide our therapy. PMID:26670815

  11. [Prolonged neuromuscular block induced by mivacurium in a patient treated with cyclophosphamide].

    PubMed

    Vigouroux, D; Voltaire, L

    1995-01-01

    A case is reported of prolonged neuromuscular block after mivacurium chloride for laparoscopic cholecystectomy, in a 45 years old patient, treated with cyclophosphamide for a Wegener's granulomatosis. The neuromuscular function monitoring by train-of-four showed a duration of action of 75 min after an intubation dose of 0.20 mg.kg-1. Additional bolus of 1 mg, corresponding to 25% of usual doses, every 10 or 15 min, were sufficient for maintaining muscle relaxation. Spontaneous recovery, without any antagonization, lasted 40 min for a TOF ratio (T4/T1) > or = 70%. Recovery index from 25 to 75% were 13 min. Plasma butyrilcholinesterases activity were reduced to a level of 50%. With reference to literature about succinylcholine, the responsibility of cyclophosphamide is likely, and discussed. This observation shows the value of monitoring the neuromuscular transmission. PMID:8745976

  12. Neuromuscular electrical stimulation in critically ill patients in the intensive care unit: a systematic review

    PubMed Central

    Ferreira, Lucas Lima; Vanderlei, Luiz Carlos Marques; Valenti, Vitor Engrácia

    2014-01-01

    Objective To analyze the outcomes enabled by the neuromuscular electric stimulation in critically ill patients in intensive care unit assisted. Methods A systematic review of the literature by means of clinical trials published between 2002 and 2012 in the databases LILACS, SciELO, MEDLINE and PEDro using the descriptors “intensive care unit”, “physical therapy”, “physiotherapy”, “electric stimulation” and “randomized controlled trials”. Results We included four trials. The sample size varied between 8 to 33 individuals of both genders, with ages ranging between 52 and 79 years, undergoing invasive mechanical ventilation. Of the articles analyzed, three showed significant benefits of neuromuscular electrical stimulation in critically ill patients, such as improvement in peripheral muscle strength, exercise capacity, functionality, or loss of thickness of the muscle layer. Conclusion The application of neuromuscular electrical stimulation promotes a beneficial response in critically patients in intensive care. PMID:25295458

  13. Sympathetic innervation controls homeostasis of neuromuscular junctions in health and disease

    PubMed Central

    Khan, Muzamil Majid; Lustrino, Danilo; Silveira, Willian A.; Wild, Franziska; Straka, Tatjana; Issop, Yasmin; O’Connor, Emily; Cox, Dan; Reischl, Markus; Marquardt, Till; Labeit, Dittmar; Labeit, Siegfried; Benoit, Evelyne; Molgó, Jordi; Lochmüller, Hanns; Witzemann, Veit; Kettelhut, Isis C.; Navegantes, Luiz C. C.; Pozzan, Tullio; Rudolf, Rüdiger

    2016-01-01

    The distribution and function of sympathetic innervation in skeletal muscle have largely remained elusive. Here we demonstrate that sympathetic neurons make close contact with neuromuscular junctions and form a network in skeletal muscle that may functionally couple different targets including blood vessels, motor neurons, and muscle fibers. Direct stimulation of sympathetic neurons led to activation of muscle postsynaptic β2-adrenoreceptor (ADRB2), cAMP production, and import of the transcriptional coactivator peroxisome proliferator-activated receptor γ-coactivator 1α (PPARGC1A) into myonuclei. Electrophysiological and morphological deficits of neuromuscular junctions upon sympathectomy and in myasthenic mice were rescued by sympathicomimetic treatment. In conclusion, this study identifies the neuromuscular junction as a target of the sympathetic nervous system and shows that sympathetic input is crucial for synapse maintenance and function. PMID:26733679

  14. Bone mineral density evaluation among patients with neuromuscular scoliosis secondary to cerebral palsy☆

    PubMed Central

    Rezende, Rodrigo; Cardoso, Igor Machado; Leonel, Rayana Bomfim; Perim, Larissa Grobério Lopes; Oliveira, Tarcísio Guimarães Silva; Jacob Júnior, Charbel; Júnior, José Lucas Batista; Lourenço, Rafael Burgomeister

    2014-01-01

    Objective To evaluate bone mineral density among patients with neuromuscular scoliosis secondary to quadriplegic cerebral palsy. Methods This was a descriptive prospective study in which both bone densitometric and anthropometric data were evaluated. The inclusion criteria used were that the patients should present quadriplegic cerebral palsy, be confined to a wheelchair, be between 10 and 20 years of age and present neuromuscular scoliosis. Results We evaluated 31 patients (20 females) with a mean age of 14.2 years. Their mean biceps circumference, calf circumference and body mass index were 19.4 cm, 18.6 cm and 16.9 kg/m2, respectively. The mean standard deviation from bone densitometry was −3.2 (z-score), which characterizes osteoporosis. Conclusion There is high incidence of osteoporosis in patients with neuromuscular scoliosis secondary to quadriplegic cerebral palsy. PMID:26229882

  15. Naturally occurring plant polyphenols as potential therapies for inherited neuromuscular diseases.

    PubMed

    Fuller, Heidi R; Humphrey, Emma L; Morris, Glenn E

    2013-11-01

    There are several lines of laboratory-based evidence emerging to suggest that purified polyphenol compounds such as resveratrol, found naturally in red grapes, epigallocatechin galate from green tea and curcumin from turmeric, might be useful for the treatment of various inherited neuromuscular diseases, including spinal muscular atrophy, Duchenne muscular dystrophy and Charcot-Marie-Tooth disease. Here, we critically examine the scientific evidence related to the known molecular effects that these polyphenols have on different models of inherited neuromuscular disease, with particular attention to problems with the validity of in vitro evidence. We also present proteomic evidence that polyphenols have in vitro effects on cells related to metal ion chelation in cell-culture media. Although their precise mechanisms of action remain somewhat elusive, polyphenols could be an attractive approach to therapy for inherited neuromuscular disease, especially since they may be safer to use on young children, compared with some of the other drug candidates.

  16. Femoral quadriceps neuromuscular electrical stimulation after total knee arthroplasty: a systematic review

    PubMed Central

    Volpato, Helena Bruna Bettoni; Szego, Paulo; Lenza, Mario; Milan, Silvia Lefone; Talerman, Claudia; Ferretti, Mario

    2016-01-01

    ABSTRACT The purpose of this study was to evaluate the effects of neuromuscular electrical stimulation in patients submitted to total knee arthroplasty. This was a systematic review with no language or publication status restriction. Our search was made in Cochrane Library, MEDLINE, Embase and LILACS. Randomized or quasi-randomized clinical trials evaluating neuromuscular electrical stimulation after total knee arthroplasty were included. Four studies with moderate risk of bias and low statistical power were included, totalizing 376 participants. There was no statistically significant difference in knee function, pain and range of motion during 12 month follow-up. This review concluded that neuromuscular electrical stimulation was less effective than traditional rehabilitation in function, muscular strength and range of motion. However, this technique was useful for quadriceps activation during the first days after surgery. PMID:26537511

  17. The use of in-flight foot pressure as a countermeasure to neuromuscular degradation

    NASA Technical Reports Server (NTRS)

    Layne, C. S.; Mulavara, A. P.; Pruett, C. J.; McDonald, P. V.; Kozlovskaya, I. B.; Bloomberg, J. J.

    1998-01-01

    The purpose of this study was to determine whether applying foot pressure to unrestrained subjects during space flight could enhance the neuromuscular activation associated with rapid arm movements. Four men performed unilateral arm raises while wearing--or not wearing--specially designed boots during a 81- or 115-day space flight. Arm acceleration and surface EMG were obtained from selected lower limb and trunk muscles. Pearson r coefficients were used to evaluate similarity in phasic patterns between the two in-flight conditions. In-flight data also were magnitude normalized to the mean voltage value of the muscle activation waveforms obtained during the no-foot-pressure condition to facilitate comparison of activation amplitude between the two in-flight conditions. Foot pressure enhanced neuromuscular activation and somewhat modified the phasic features of the neuromuscular activation during the arm raises.

  18. Naturally occurring plant polyphenols as potential therapies for inherited neuromuscular diseases.

    PubMed

    Fuller, Heidi R; Humphrey, Emma L; Morris, Glenn E

    2013-11-01

    There are several lines of laboratory-based evidence emerging to suggest that purified polyphenol compounds such as resveratrol, found naturally in red grapes, epigallocatechin galate from green tea and curcumin from turmeric, might be useful for the treatment of various inherited neuromuscular diseases, including spinal muscular atrophy, Duchenne muscular dystrophy and Charcot-Marie-Tooth disease. Here, we critically examine the scientific evidence related to the known molecular effects that these polyphenols have on different models of inherited neuromuscular disease, with particular attention to problems with the validity of in vitro evidence. We also present proteomic evidence that polyphenols have in vitro effects on cells related to metal ion chelation in cell-culture media. Although their precise mechanisms of action remain somewhat elusive, polyphenols could be an attractive approach to therapy for inherited neuromuscular disease, especially since they may be safer to use on young children, compared with some of the other drug candidates. PMID:24215348

  19. Sympathetic innervation controls homeostasis of neuromuscular junctions in health and disease.

    PubMed

    Khan, Muzamil Majid; Lustrino, Danilo; Silveira, Willian A; Wild, Franziska; Straka, Tatjana; Issop, Yasmin; O'Connor, Emily; Cox, Dan; Reischl, Markus; Marquardt, Till; Labeit, Dittmar; Labeit, Siegfried; Benoit, Evelyne; Molgó, Jordi; Lochmüller, Hanns; Witzemann, Veit; Kettelhut, Isis C; Navegantes, Luiz C C; Pozzan, Tullio; Rudolf, Rüdiger

    2016-01-19

    The distribution and function of sympathetic innervation in skeletal muscle have largely remained elusive. Here we demonstrate that sympathetic neurons make close contact with neuromuscular junctions and form a network in skeletal muscle that may functionally couple different targets including blood vessels, motor neurons, and muscle fibers. Direct stimulation of sympathetic neurons led to activation of muscle postsynaptic β2-adrenoreceptor (ADRB2), cAMP production, and import of the transcriptional coactivator peroxisome proliferator-activated receptor γ-coactivator 1α (PPARGC1A) into myonuclei. Electrophysiological and morphological deficits of neuromuscular junctions upon sympathectomy and in myasthenic mice were rescued by sympathicomimetic treatment. In conclusion, this study identifies the neuromuscular junction as a target of the sympathetic nervous system and shows that sympathetic input is crucial for synapse maintenance and function. PMID:26733679

  20. Activation of Matrix Metalloproteinase-3 is altered at the frog neuromuscular junction following changes in synaptic activity.

    PubMed

    VanSaun, M; Humburg, B C; Arnett, M G; Pence, M; Werle, M J

    2007-09-15

    The extracellular matrix surrounding the neuromuscular junction is a highly specialized and dynamic structure. Matrix Metalloproteinases are enzymes that sculpt the extracellular matrix. Since synaptic activity is critical to the structure and function of this synapse, we investigated whether changes in synaptic activity levels could alter the activity of Matrix Metalloproteinases at the neuromuscular junction. In particular, we focused on Matrix Metalloproteinase 3 (MMP3), since antibodies to MMP3 recognize molecules at the frog neuromuscular junction, and MMP3 cleaves a number of synaptic basal lamina molecules, including agrin. Here we show that the fluorogenic compound (M2300) can be used to perform in vivo proteolytic imaging of the frog neuromuscular junction to directly measure the activity state of MMP3. Application of this compound reveals that active MMP3 is concentrated at the normal frog neuromuscular junction, and is tightly associated with the terminal Schwann cell. Blocking presynaptic activity via denervation, or TTX nerve blockade, results in a decreased level of active MMP3 at the neuromuscular junction. The loss of active MMP3 at the neuromuscular junction in denervated muscles can result from decreased activation of pro-MMP3, or it could result from increased inhibition of MMP3. These results support the hypothesis that changes in synaptic activity can alter the level of active MMP3 at the neuromuscular junction. PMID:17525979

  1. Effect of a 6-week dynamic neuromuscular training programme on ankle joint function: A Case report

    PubMed Central

    2011-01-01

    Background Ankle joint sprain and the subsequent development of chronic ankle instability (CAI) are commonly encountered by clinicians involved in the treatment and rehabilitation of musculoskeletal injuries. It has recently been advocated that ankle joint post-sprain rehabilitation protocols should incorporate dynamic neuromuscular training to enhance ankle joint sensorimotor capabilities. To date no studies have reported on the effects of dynamic neuromuscular training on ankle joint positioning during landing from a jump, which has been reported as one of the primary injury mechanisms for ankle joint sprain. This case report details the effects of a 6-week dynamic neuromuscular training programme on ankle joint function in an athlete with CAI. Methods The athlete took part in a progressive 6-week dynamic neuromuscular training programme which incorporated postural stability, strengthening, plyometric, and speed/agility drills. The outcome measures chosen to assess for interventional efficacy were: [1] Cumberland Ankle Instability Tool (CAIT) scores, [2] Star Excursion Balance Test (SEBT) reach distances, [3] ankle joint plantar flexion during drop landing and drop vertical jumping, and [4] ground reaction forces (GRFs) during walking. Results CAIT and SEBT scores improved following participation in the programme. The angle of ankle joint plantar flexion decreased at the point of initial contact during the drop landing and drop vertical jumping tasks, indicating that the ankle joint was in a less vulnerable position upon landing following participation in the programme. Furthermore, GRFs were reduced whilst walking post-intervention. Conclusions The 6-week dynamic neuromuscular training programme improved parameters of ankle joint sensorimotor control in an athlete with CAI. Further research is now required in a larger cohort of subjects to determine the effects of neuromuscular training on ankle joint injury risk factors. PMID:21658224

  2. Installation of the hand influences acceleromyography measurement. A comparison with mechanomyography during neuromuscular recovery.

    PubMed

    Dubois, Ph E; Gourdin, M; Russell, K; Jamart, J

    2005-01-01

    Acceleromyography is commonly used to monitor perioperative neuromuscular blockade and to prevent residual neuromuscular blockade at the time of tracheal extubation. However, there are problems associated with this method, such as obtaining stable values, particularly beneath the surgical fields. We compared TOF ratios obtained on both hands simultaneously using on one side mechanomyography and on the other acceleromyography, installed in four different ways: the hand simply lying on a board, fingers fixed with tape, use of the hand adaptor or the TOF-tube. Further to maintaining free thumb movement, the TOF-tube improves feasibility of acceleromyography by reducing the measurement variability while retaining accuracy. PMID:16013661

  3. Neuromuscular Electrical Stimulation for Mobility Support of Elderly

    PubMed Central

    2015-01-01

    The stimulator for neuromuscular electrical stimulation for mobility support of elderly is not very complicated, but for application within “MOBIL” we have some additional demands to fulfill. First we have specific safety issues for this user group. A powerful compliance management system is crucial not only to guide daily application, but for creating hard data for the scientific outcome. We also need to assure easy handling of the stimulator, because the subjects are generally not able to cope with too difficult and complex motor skills. So, we developed five generations of stimulators and optimizing solutions after field tests. We are already planning the sixth generation with wireless control of the stimulation units by the central main handheld control unit. In a prototype, we have implemented a newly available high capacity memory, a breakthrough in “compliance data storage” as they offer the necessary high storage capacity and fast data handling for an affordable prize. The circuit also contains a 3D accelerometer sensor which acts as a further important safety features: if the control unit drops, this event is detected automatically by the sensor and activates an emergency switch-off that disables the stimulation to avoid associated risks. Further, we have implemented a hardware emergence shutdown and other safety measures. Finally, in the last example muscle torque measurements are referenced with compliance data. In the study normalized maximum voluntary contraction (MVC) and maximum stimulation induced contraction (MSC) were assessed in regular check-ups along the training period. With additional consideration of adjusted stimulation intensity for training out of the compliance data records we are able to estimate the induced contraction strength, which turned out to amount in average 11% of MVC. This value may seem on a first sight rather low, and ought to be considered in relation to the results at the end of the training period. Therefore the

  4. Neuromuscular Electrical Stimulation for Mobility Support of Elderly.

    PubMed

    Mayr, Winfried

    2015-08-24

    The stimulator for neuromuscular electrical stimulation for mobility support of elderly is not very complicated, but for application within "MOBIL" we have some additional demands to fulfill. First we have specific safety issues for this user group. A powerful compliance management system is crucial not only to guide daily application, but for creating hard data for the scientific outcome. We also need to assure easy handling of the stimulator, because the subjects are generally not able to cope with too difficult and complex motor skills. So, we developed five generations of stimulators and optimizing solutions after field tests. We are already planning the sixth generation with wireless control of the stimulation units by the central main handheld control unit. In a prototype, we have implemented a newly available high capacity memory, a breakthrough in "compliance data storage" as they offer the necessary high storage capacity and fast data handling for an affordable prize. The circuit also contains a 3D accelerometer sensor which acts as a further important safety features: if the control unit drops, this event is detected automatically by the sensor and activates an emergency switch-off that disables the stimulation to avoid associated risks. Further, we have implemented a hardware emergence shutdown and other safety measures. Finally, in the last example muscle torque measurements are referenced with compliance data. In the study normalized maximum voluntary contraction (MVC) and maximum stimulation induced contraction (MSC) were assessed in regular check-ups along the training period. With additional consideration of adjusted stimulation intensity for training out of the compliance data records we are able to estimate the induced contraction strength, which turned out to amount in average 11% of MVC. This value may seem on a first sight rather low, and ought to be considered in relation to the results at the end of the training period. Therefore the

  5. Neuromuscular characteristics and fatigue during 10 km running.

    PubMed

    Paavolainen, L; Nummela, A; Rusko, H; Häkkinen, K

    1999-11-01

    This study investigated neuromuscular characteristics and fatigue during 10 km running (10 K) performance in well-trained endurance athletes with different distance running capability. Nine high (HC) and ten low (LC) caliber endurance athletes performed the 10 K on a 200 m indoor track, constant velocity lap (CVL, 4.5 m x s(-1)) 5 times during the course of the 10 K and maximal 20 m speed test before (20 m(b)) and after (20 m(a)) the 10 K. Running velocity (V), ground contact times (CT), ground reaction forces (F) and electromyographic activity (EMG) of the leg muscles (vastus lateralis; VL, biceps femoris; BF, gastrocnemius; GA) were measured during 20 m(b), 20 m(a), and CVLs. The 10 K times differed (p<0.001) between HC and LC (36.3+/-1.2 and 39.2+/-2.0 min, respectively) but no differences were observed in 20 m(b) velocity. The 10 K led to significant (p<0.05) decreases in V, F and integrated EMG (IEMG) and increases in CTs of 20 m(a) in both groups. No changes were observed in HC or LC in F and IEMG during the CVLs but HC showed shorter (p<0.05) mean CT of CVLs than LC. A significant correlation (r = -0.56, p<0.05) was observed between the mean CT of CVLs and velocity of 10 K (V10K). Pre-activity of GA in relation to the IEMG of the total contact phase during the CVLs was higher (p<0.05) in HC than LC. The relative IEMGs of VL and GA in the propulsion phase compared to the IEMG of the 20 m(b) were lower (p<0.05) in HC than LC. In conclusion, marked fatigue took place in both HC and LC during the 10 K but the fatigue-induced changes in maximal 20 m run did not differentiate endurance athletes with different V10K. However, a capability to produce force rapidly throughout the 10 K accompanied with optimal preactivation and contact phase activation seem to be important for 10 km running performance in well trained endurance athletes.

  6. Genetic and evolutionary analysis of the Drosophila larval neuromuscular junction

    NASA Astrophysics Data System (ADS)

    Campbell, Megan

    Although evolution of brains and behaviors is of fundamental biological importance, we lack comprehensive understanding of the general principles governing these processes or the specific mechanisms and molecules through which the evolutionary changes are effected. Because synapses are the basic structural and functional units of nervous systems, one way to address these problems is to dissect the genetic and molecular pathways responsible for morphological evolution of a defined synapse. I have undertaken such an analysis by examining morphology of the larval neuromuscular junction (NMJ) in wild caught D. melanogaster as well as in over 20 other species of Drosophila. Whereas variation in NMJ morphology within a species is limited, I discovered a surprisingly extensive variation among different species. Compared with evolution of other morphological traits, NMJ morphology appears to be evolving very rapidly. Moreover, my data indicate that natural selection rather than genetic drift is primarily responsible for evolution of NMJ morphology. To dissect underlying molecular mechanisms that may govern NMJ growth and evolutionary divergence, I focused on a naturally occurring variant in D. melanogaster that causes NMJ overgrowth. I discovered that the variant mapped to Mob2, a gene encoding a kinase adapter protein originally described in yeast as a member of the Mitotic Exit Network (MEN). I have subsequently examined mutations in the Drosophila orthologs of all the core components of the yeast MEN and found that all of them function as part of a common pathway that acts presynaptically to negatively regulate NMJ growth. As in the regulation of yeast cytokinesis, these components of the MEN appear to act ultimately by regulating actin dynamics during the process of bouton growth and division. These studies have thus led to the discovery of an entirely new role for the MEN---regulation of synaptic growth---that is separate from its function in cell division. This work

  7. Regeneration of the active zone at the frog neuromuscular junction

    PubMed Central

    1984-01-01

    The active zone is a unique specialization of the presynaptic membrane and is believed to be the site of transmitter release. The formation of the active zone and the relationship of this process to transmitter release were studied at reinnervated neuromuscular junctions in the frog. At different times after a nerve crush, the cutaneous pectoris muscles were examined with intracellular recording recording and freeze- fracture electron microscopy. The P face of a normal active zone typically consists of two double rows of particles lined up in a continuous segment located opposite a junctional fold. In the initial stage of reinnervation, clusters of large intramembrane particles surrounding membrane elevations appeared on the P face of nerve terminals. Like normal active zones, these clusters were aligned with junctional folds. Vesicle openings, which indicate transmitter release, were seen at these primitive active zones, even though intramembrane particles were not yet organized into the normal pattern of two double rows. The length of active zones at this stage was only approximately 15% of normal. During the secondary stage, every junction was reinnervated and most active zones had begun to organize into the normal pattern with normal orientation. Unlike normal, there were often two or more discontinuous short segments of active zone aligned with the same junctional fold. The total length of active zone per junctional fold increased to one-third of normal, mainly because of the greater number of segments. In the third stage, the number of active zone segments per junctional fold showed almost no change when compared with the secondary stage. However, individual segments elongated and increased the total length of all active zone segments per junctional fold to about two-thirds of the normal length. The dynamic process culminated in the final stage, during which elongating active zones appeared to join together and the number of active zone segments per

  8. Effect of magnesium sulphate on sugammadex reversal time for neuromuscular blockade: a randomised controlled study.

    PubMed

    Germano Filho, P A; Cavalcanti, I L; Barrucand, L; Verçosa, N

    2015-08-01

    Magnesium potentiates neuromuscular blockade. Sugammadex reverses rocuronium-induced blockade. The aim of this study was to determine the effect of pre-treatment with magnesium sulphate on sugammadex reversal time for neuromuscular blockade. Seventy-three patients were randomly assigned to receive magnesium sulphate (40 mg.kg(-1) ) or saline intravenously. After anaesthetic induction, continuous train-of-four monitoring was performed and rocuronium was administered (0.6 mg.kg(-1) ). When a second twitch appeared, the patients received sugammadex (2 mg.kg(-1) ). The median (IQR [range]) reversal time of moderate neuromuscular blockade to a train-of-four ratio of 0.9 facilitated by sugammadex was 115 (93-177.5 [68-315]) s in the magnesium group and 120 (105-140 [70-298]) s in the saline group (p = 0.79). The median (IQR [range]) clinical duration was 45 (35.5-53 [22-102]) min in the magnesium group and 37 (31-43 [19-73]) min in the saline group (p = 0.031). Pre-treatment with magnesium did not significantly affect sugammadex reversal time of moderate neuromuscular blockade induced by rocuronium.

  9. A Distinct Perisynaptic Glial Cell Type Forms Tripartite Neuromuscular Synapses in the Drosophila Adult

    PubMed Central

    Strauss, Alexandra L.; Kawasaki, Fumiko; Ordway, Richard W.

    2015-01-01

    Previous studies of Drosophila flight muscle neuromuscular synapses have revealed their tripartite architecture and established an attractive experimental model for genetic analysis of glial function in synaptic transmission. Here we extend these findings by defining a new Drosophila glial cell type, designated peripheral perisynaptic glia (PPG), which resides in the periphery and interacts specifically with fine motor axon branches forming neuromuscular synapses. Identification and specific labeling of PPG was achieved through cell type-specific RNAi-mediated knockdown (KD) of a glial marker, Glutamine Synthetase 2 (GS2). In addition, comparison among different Drosophila neuromuscular synapse models from adult and larval developmental stages indicated the presence of tripartite synapses on several different muscle types in the adult. In contrast, PPG appear to be absent from larval body wall neuromuscular synapses, which do not exhibit a tripartite architecture but rather are imbedded in the muscle plasma membrane. Evolutionary conservation of tripartite synapse architecture and peripheral perisynaptic glia in vertebrates and Drosophila suggests ancient and conserved roles for glia-synapse interactions in synaptic transmission. PMID:26053860

  10. Exercise-induced dehydration does not alter time trial or neuromuscular performance.

    PubMed

    Stewart, C J; Whyte, D G; Cannon, J; Wickham, J; Marino, F E

    2014-08-01

    This study examined the effect of exercise-induced dehydration by ~4% body mass loss on 5-km cycling time trial (TT) performance and neuromuscular drive, independent of hyperthermia. 7 active males were dehydrated on 2 occasions, separated by 7 d. Participants remained dehydrated (DEH, -3.8±0.5%) or were rehydrated (REH, 0.2±0.6%) over 2 h before completing the TT at 18-25 °C, 20-30% relative humidity. Neuromuscular function was determined before dehydration and immediately prior the TT. The TT started at the same core temperature (DEH, 37.3±0.3°C; REH, 37.0±0.2 °C (P>0.05). Neither TT performance (DEH, 7.31±1.5 min; REH, 7.10±1.3 min (P>0.05)) or % voluntary activation were affected by dehydration (DEH, 88.7±6.4%; REH, 90.6±6.1% (P>0.05)). Quadriceps peak torque was significantly elevated in both trials prior to the TT (P<0.05), while a 19% increase in the rate of potentiated peak twitch torque development (P<0.05) was observed in the DEH trial only. All other neuromuscular measures were similar between trials. Short duration TT performance and neuromuscular function are not reduced by dehydration, independent of hyperthermia.

  11. Current Methodological Issues in the Study of Children with Inherited Neuromuscular Disorders

    ERIC Educational Resources Information Center

    Mercuri, Eugenio; Messina, Sonia; Pane, Marika; Bertini, Enrico

    2008-01-01

    Several clinical trials assessing children with hereditary neuromuscular disorders have been performed over the last decade. These studies highlighted issues related to design and performance of clinical studies assessing children with this group of disorders. This article reviews recent literature and clinical experience in this area,…

  12. Evidence-Based Systematic Review: Effects of Neuromuscular Electrical Stimulation on Swallowing and Neural Activation

    ERIC Educational Resources Information Center

    Clark, Heather; Lazarus, Cathy; Arvedson, Joan; Schooling, Tracy; Frymark, Tobi

    2009-01-01

    Purpose: To systematically review the literature examining the effects of neuromuscular electrical stimulation (NMES) on swallowing and neural activation. The review was conducted as part of a series examining the effects of oral motor exercises (OMEs) on speech, swallowing, and neural activation. Method: A systematic search was conducted to…

  13. Short day lengths delay development of the SNB neuromuscular system in the Siberian hamster, Phodopus sungorus.

    PubMed

    Hegstrom, C D; Breedlove, S M

    1998-06-15

    The Siberian hamster, Phodopus sungorus, breeds seasonally. In the laboratory, the seasonal breeding can be controlled by photoperiod, which affects the durations of nightly melatonin secretions. Winterlike short day lengths induce gonadal regression in adult animals, and pups born and maintained in short days undergo gonadal development much later than animals born into long days. The spinal nucleus of the bulbocavernosus (SNB) and its target muscles, the bulbocavernosus (BC) and levator ani (LA), comprise a sexually dimorphic, androgensensitive neuromuscular system involved in male reproduction. The SNB neuromuscular system was studied in male Siberian hamsters maintained from conception in short-day (8:16 h light/dark cycle) versus long-day (16:8 h light/dark cycle) conditions. At 40-47 days of age, development of three components of the SNB neuromuscular system were all significantly delayed in hamsters raised in the short photoperiod: BC/LA muscle weight, the size of SNB motoneuronal somata, and the area of the neuromuscular junctions at the BC/LA muscles of short-day hamsters were each significantly reduced relative to those of longday counterparts. Thus, development of the SNB reproductive system is delayed under short day lengths in this species.

  14. Proprioceptive Neuromuscular Facilitation Flexibility Techniques: Acute Effects on Arterial Blood Pressure.

    ERIC Educational Resources Information Center

    Cornelius, William L.; Craft-Hamm, Kelley

    1988-01-01

    The effects of stretching techniques on arterial blood pressure (ABP) were studied in three groups of 20 men each. Each group performed one of three proprioceptive neuromuscular facilitation (PNF) techniques. Results are presented. The study indicates that the benefits of stretching may outweigh the risk of elevated ABP. (JL)

  15. A system for studying mechanisms of neuromuscular junction development and maintenance

    PubMed Central

    Vilmont, Valérie; Ouanounou, Gilles

    2016-01-01

    The neuromuscular junction (NMJ), a cellular synapse between a motor neuron and a skeletal muscle fiber, enables the translation of chemical cues into physical activity. The development of this special structure has been subject to numerous investigations, but its complexity renders in vivo studies particularly difficult to perform. In vitro modeling of the neuromuscular junction represents a powerful tool to delineate fully the fine tuning of events that lead to subcellular specialization at the pre-synaptic and post-synaptic sites. Here, we describe a novel heterologous co-culture in vitro method using rat spinal cord explants with dorsal root ganglia and murine primary myoblasts to study neuromuscular junctions. This system allows the formation and long-term survival of highly differentiated myofibers, motor neurons, supporting glial cells and functional neuromuscular junctions with post-synaptic specialization. Therefore, fundamental aspects of NMJ formation and maintenance can be studied using the described system, which can be adapted to model multiple NMJ-associated disorders. PMID:27226316

  16. A system for studying mechanisms of neuromuscular junction development and maintenance.

    PubMed

    Vilmont, Valérie; Cadot, Bruno; Ouanounou, Gilles; Gomes, Edgar R

    2016-07-01

    The neuromuscular junction (NMJ), a cellular synapse between a motor neuron and a skeletal muscle fiber, enables the translation of chemical cues into physical activity. The development of this special structure has been subject to numerous investigations, but its complexity renders in vivo studies particularly difficult to perform. In vitro modeling of the neuromuscular junction represents a powerful tool to delineate fully the fine tuning of events that lead to subcellular specialization at the pre-synaptic and post-synaptic sites. Here, we describe a novel heterologous co-culture in vitro method using rat spinal cord explants with dorsal root ganglia and murine primary myoblasts to study neuromuscular junctions. This system allows the formation and long-term survival of highly differentiated myofibers, motor neurons, supporting glial cells and functional neuromuscular junctions with post-synaptic specialization. Therefore, fundamental aspects of NMJ formation and maintenance can be studied using the described system, which can be adapted to model multiple NMJ-associated disorders. PMID:27226316

  17. Family Stress with Chronic Childhood Illness: Cystic Fibrosis, Neuromuscular Disease, and Renal Disease.

    ERIC Educational Resources Information Center

    Holroyd, Jean; Guthrie, Donald

    1986-01-01

    Parents of children with neuromuscular disease, cystic fibrosis, and renal disease were compared with parents of control subjects matched by age to the clinical cases. The three clinical groups exhibited different patterns of stressful response, consistent with the nature of their illnesses and the requirements for care imposed on the families.…

  18. Metabolic, cardiorespiratory, and neuromuscular fitness performance in children with cerebral palsy: A comparison with healthy youth.

    PubMed

    García, Claudia Cardona; Alcocer-Gamboa, Alberto; Ruiz, Margarita Pérez; Caballero, Ignacio Martínez; Faigenbaum, Avery D; Esteve-Lanao, Jonathan; Saiz, Beatriz Moral; Lorenzo, Teresa Martín; Lara, Sergio Lerma

    2016-04-01

    The aim of this study was to assess metabolic, cardiorespiratory, and neuromuscular fitness parameters in children with spastic cerebral palsy (CP) and to compare these findings with typically developing children. 40 children with CP (21 males, 19 females; mean age, 11.0±3.3 yr; range, 6.5-17.1 yr; Gross Motor Function Classification System levels 1 or 2) and 40 healthy, age- and sex-matched children completed a test battery that consisted of 8 tests and 28 measures that assessed cardio-respiratory fitness, energy expenditure, anaerobic endurance, muscle strength, agility, stability and flexibility. Children with CP had significantly lower performance (P<0.05) on most cardiorespiratory and metabolic tests than those of healthy children, Differences in neuromuscular measures of muscular strength, speed, agility, anaerobic endurance, and flexibility between groups were most apparent. Grouped differences in cardiorespiratory variables revealed a 25% difference in performance, whereas grouped differences in metabolic and neuromuscular measures were 43% and 60%, respectively. The physical fitness of contemporary children with CP is significantly less than healthy, age-matched children. Significant differences in neuromuscular measures between groups can aid in the identification of specific fitness abilities in need of improvement in this population. PMID:27162775

  19. Decreased muscle endurance associated with diabetic neuropathy may be attributed partially to neuromuscular transmission failure.

    PubMed

    Allen, Matti D; Kimpinski, Kurt; Doherty, Timothy J; Rice, Charles L

    2015-04-15

    Diabetic polyneuropathy (DPN) can cause muscle atrophy, weakness, contractile slowing, and neuromuscular transmission instability. Our objective was to assess the response of the impaired neuromuscular system of DPN in humans when stressed with a sustained maximal voluntary contraction (MVC). Baseline MVC and evoked dorsiflexor contractile properties were assessed in DPN patients (n = 10) and controls (n = 10). Surface electromyography was used to record tibialis anterior evoked maximal compound muscle action potentials (CMAPs) and neuromuscular activity during MVCs. Participants performed a sustained isometric dorsiflexion MVC for which task termination was determined by the inability to sustain ≥60% MVC torque. The fatigue protocol was immediately followed by a maximal twitch, with additional maximal twitches and MVCs assessed at 30 s and 2 min postfatigue. DPN patients fatigued ∼21% more quickly than controls (P < 0.05) and featured less relative electromyographic activity during the first one-third of the fatigue protocol compared with controls (P < 0.05). Immediately following fatigue, maximal twitch torque was reduced similarly (∼20%) in both groups, and concurrently CMAPs were reduced (∼12%) in DPN patients, whereas they were unaffected in controls (P > 0.05). Twitch torque and CMAP amplitude recovered to baseline 30 s postfatigue. Additionally, at 30 s postfatigue, both groups had similar (∼10%) reductions in MVC torque relative to baseline, and MVC strength recovered by 2 min postfatigue. We conclude DPN patients possess less endurance than controls, and neuromuscular transmission failure may contribute to this greater fatigability. PMID:25663671

  20. Metabolic, cardiorespiratory, and neuromuscular fitness performance in children with cerebral palsy: A comparison with healthy youth

    PubMed Central

    García, Claudia Cardona; Alcocer-Gamboa, Alberto; Ruiz, Margarita Pérez; Caballero, Ignacio Martínez; Faigenbaum, Avery D.; Esteve-Lanao, Jonathan; Saiz, Beatriz Moral; Lorenzo, Teresa Martín; Lara, Sergio Lerma

    2016-01-01

    The aim of this study was to assess metabolic, cardiorespiratory, and neuromuscular fitness parameters in children with spastic cerebral palsy (CP) and to compare these findings with typically developing children. 40 children with CP (21 males, 19 females; mean age, 11.0±3.3 yr; range, 6.5–17.1 yr; Gross Motor Function Classification System levels 1 or 2) and 40 healthy, age- and sex-matched children completed a test battery that consisted of 8 tests and 28 measures that assessed cardio-respiratory fitness, energy expenditure, anaerobic endurance, muscle strength, agility, stability and flexibility. Children with CP had significantly lower performance (P<0.05) on most cardiorespiratory and metabolic tests than those of healthy children, Differences in neuromuscular measures of muscular strength, speed, agility, anaerobic endurance, and flexibility between groups were most apparent. Grouped differences in cardiorespiratory variables revealed a 25% difference in performance, whereas grouped differences in metabolic and neuromuscular measures were 43% and 60%, respectively. The physical fitness of contemporary children with CP is significantly less than healthy, age-matched children. Significant differences in neuromuscular measures between groups can aid in the identification of specific fitness abilities in need of improvement in this population. PMID:27162775

  1. Decreased muscle endurance associated with diabetic neuropathy may be attributed partially to neuromuscular transmission failure

    PubMed Central

    Kimpinski, Kurt; Doherty, Timothy J.; Rice, Charles L.

    2015-01-01

    Diabetic polyneuropathy (DPN) can cause muscle atrophy, weakness, contractile slowing, and neuromuscular transmission instability. Our objective was to assess the response of the impaired neuromuscular system of DPN in humans when stressed with a sustained maximal voluntary contraction (MVC). Baseline MVC and evoked dorsiflexor contractile properties were assessed in DPN patients (n = 10) and controls (n = 10). Surface electromyography was used to record tibialis anterior evoked maximal compound muscle action potentials (CMAPs) and neuromuscular activity during MVCs. Participants performed a sustained isometric dorsiflexion MVC for which task termination was determined by the inability to sustain ≥60% MVC torque. The fatigue protocol was immediately followed by a maximal twitch, with additional maximal twitches and MVCs assessed at 30 s and 2 min postfatigue. DPN patients fatigued ∼21% more quickly than controls (P < 0.05) and featured less relative electromyographic activity during the first one-third of the fatigue protocol compared with controls (P < 0.05). Immediately following fatigue, maximal twitch torque was reduced similarly (∼20%) in both groups, and concurrently CMAPs were reduced (∼12%) in DPN patients, whereas they were unaffected in controls (P > 0.05). Twitch torque and CMAP amplitude recovered to baseline 30 s postfatigue. Additionally, at 30 s postfatigue, both groups had similar (∼10%) reductions in MVC torque relative to baseline, and MVC strength recovered by 2 min postfatigue. We conclude DPN patients possess less endurance than controls, and neuromuscular transmission failure may contribute to this greater fatigability. PMID:25663671

  2. Man-Machine Interface System for Neuromuscular Training and Evaluation Based on EMG and MMG Signals

    PubMed Central

    de la Rosa, Ramon; Alonso, Alonso; Carrera, Albano; Durán, Ramon; Fernández, Patricia

    2010-01-01

    This paper presents the UVa-NTS (University of Valladolid Neuromuscular Training System), a multifunction and portable Neuromuscular Training System. The UVa-NTS is designed to analyze the voluntary control of severe neuromotor handicapped patients, their interactive response, and their adaptation to neuromuscular interface systems, such as neural prostheses or domotic applications. Thus, it is an excellent tool to evaluate the residual muscle capabilities in the handicapped. The UVa-NTS is composed of a custom signal conditioning front-end and a computer. The front-end electronics is described thoroughly as well as the overall features of the custom software implementation. The software system is composed of a set of graphical training tools and a processing core. The UVa-NTS works with two classes of neuromuscular signals: the classic myoelectric signals (MES) and, as a novelty, the myomechanic signals (MMS). In order to evaluate the performance of the processing core, a complete analysis has been done to classify its efficiency and to check that it fulfils with the real-time constraints. Tests were performed both with healthy and selected impaired subjects. The adaptation was achieved rapidly, applying a predefined protocol for the UVa-NTS set of training tools. Fine voluntary control was demonstrated to be reached with the myoelectric signals. And the UVa-NTS demonstrated to provide a satisfactory voluntary control when applying the myomechanic signals. PMID:22163515

  3. Man-machine interface system for neuromuscular training and evaluation based on EMG and MMG signals.

    PubMed

    de la Rosa, Ramon; Alonso, Alonso; Carrera, Albano; Durán, Ramon; Fernández, Patricia

    2010-01-01

    This paper presents the UVa-NTS (University of Valladolid Neuromuscular Training System), a multifunction and portable Neuromuscular Training System. The UVa-NTS is designed to analyze the voluntary control of severe neuromotor handicapped patients, their interactive response, and their adaptation to neuromuscular interface systems, such as neural prostheses or domotic applications. Thus, it is an excellent tool to evaluate the residual muscle capabilities in the handicapped. The UVa-NTS is composed of a custom signal conditioning front-end and a computer. The front-end electronics is described thoroughly as well as the overall features of the custom software implementation. The software system is composed of a set of graphical training tools and a processing core. The UVa-NTS works with two classes of neuromuscular signals: the classic myoelectric signals (MES) and, as a novelty, the myomechanic signals (MMS). In order to evaluate the performance of the processing core, a complete analysis has been done to classify its efficiency and to check that it fulfils with the real-time constraints. Tests were performed both with healthy and selected impaired subjects. The adaptation was achieved rapidly, applying a predefined protocol for the UVa-NTS set of training tools. Fine voluntary control was demonstrated to be reached with the myoelectric signals. And the UVa-NTS demonstrated to provide a satisfactory voluntary control when applying the myomechanic signals.

  4. A robust neuromuscular system protects rat and human skeletal muscle from sarcopenia

    PubMed Central

    Pannérec, Alice; Ireland, Alex; Piasecki, Mathew; Karaz, Sonia; Jacot, Guillaume; Métairon, Sylviane; Danenberg, Esther; Raymond, Frédéric; Descombes, Patrick; McPhee, Jamie S.; Feige, Jerome N.

    2016-01-01

    Declining muscle mass and function is one of the main drivers of loss of independence in the elderly. Sarcopenia is associated with numerous cellular and endocrine perturbations, and it remains challenging to identify those changes that play a causal role and could serve as targets for therapeutic intervention. In this study, we uncovered a remarkable differential susceptibility of certain muscles to age-related decline. Aging rats specifically lose muscle mass and function in the hindlimbs, but not in the forelimbs. By performing a comprehensive comparative analysis of these muscles, we demonstrate that regional susceptibility to sarcopenia is dependent on neuromuscular junction fragmentation, loss of motoneuron innervation, and reduced excitability. Remarkably, muscle loss in elderly humans also differs in vastus lateralis and tibialis anterior muscles in direct relation to neuromuscular dysfunction. By comparing gene expression in susceptible and non-susceptible muscles, we identified a specific transcriptomic signature of neuromuscular impairment. Importantly, differential molecular profiling of the associated peripheral nerves revealed fundamental changes in cholesterol biosynthetic pathways. Altogether our results provide compelling evidence that susceptibility to sarcopenia is tightly linked to neuromuscular decline in rats and humans, and identify dysregulation of sterol metabolism in the peripheral nervous system as an early event in this process. PMID:27019136

  5. Neurophysiological Strategies for the Diagnosis of Disorders of the Neuromuscular Junction in Children

    ERIC Educational Resources Information Center

    Pitt, Matthew

    2008-01-01

    The disorders of the neuromuscular junction seen in children, the congenital myasthenic syndromes and autoimmune myasthenia gravis, are very rare. Their clinical symptoms and signs may be variable, most notably in the neonate and infant. They should enter the differential diagnosis of many different clinical presentations, such as "floppy infant"…

  6. Differential expression of active zone proteins in neuromuscular junctions suggests functional diversification.

    PubMed

    Juranek, Judyta; Mukherjee, Konark; Rickmann, Michael; Martens, Henrik; Calka, Jaroslaw; Südhof, Thomas C; Jahn, Reinhard

    2006-12-01

    Nerve terminals of the central nervous system (CNS) contain specialized release sites for synaptic vesicles, referred to as active zones. They are characterized by electron-dense structures that are tightly associated with the presynaptic plasma membrane and organize vesicle docking and priming sites. Recently, major protein constituents of active zones have been identified, including the proteins Piccolo, Bassoon, RIM, Munc13, ERCs/ELKs/CASTs and liprins. While it is becoming apparent that each of these proteins is essential for synaptic function in the CNS, it is not known to what extent these proteins are involved in synaptic function of the peripheral nervous system. Somatic neuromuscular junctions contain morphologically and functionally defined active zones with similarities to CNS synapses. In contrast, sympathetic neuromuscular varicosities lack active zone-like morphological specializations. Using immunocytochemistry at the light and electron microscopic level we have now performed a systematic investigation of all five major classes of active zone proteins in peripheral neuromuscular junctions. Our results show that somatic neuromuscular endplates contain a full complement of all active zone proteins. In contrast, varicosities of the vas deferens contain a subset of active zone proteins including Bassoon and ELKS2, with the other four components being absent. We conclude that Bassoon and ELKS2 perform independent and specialized functions in synaptic transmission of autonomic synapses.

  7. Muscle ultrasound in children: normal values and application to neuromuscular disorders.

    PubMed

    Maurits, Natalia Maria; Beenakker, Ernesto Alexander Christiaan; van Schaik, David Eric Christiaan; Fock, Johanna Maria; van der Hoeven, Johannes Harmen

    2004-08-01

    In this study, 105 healthy children (45 to 156 months old, 57 girls) were examined using ultrasound (US) imaging to obtain reference values of muscle dimensional and aspect parameters. We measured biceps and quadriceps sizes and subcutaneous tissue thickness. To quantify muscle aspect, we calculated muscle density, inhomogeneity and white-area index by digital image analysis. Age-, weight- and gender-dependencies were discussed. We demonstrated earlier that the complete set of parameters allows for differentiation between myopathies and neuropathies in adults, with high sensitivity. In this study, we investigated if these parameters have additional value in the diagnostic evaluation of 36 children with proven neuromuscular disease (20 Duchenne muscular dystrophy, 16 neuropathies). We found that density analysis provides a sensitive method for distinguishing between healthy children and children with neuromuscular disorders. We have also found that more detailed aspect analysis is necessary to further distinguish between these types of neuromuscular disorders in children. In conclusion, this set of normal muscle parameters can be used to help diagnose neuromuscular disorders in children. It will also facilitate follow-up in disease progression and therapy.

  8. Neuromuscular Adaptations to Eccentric Strength Training in Children and Adolescents with Cerebral Palsy

    ERIC Educational Resources Information Center

    Reid, Siobhan; Hamer, Peter; Alderson, Jacqueline; Lloyd, David

    2010-01-01

    Aim: To determine the neuromuscular outcomes of an eccentric strength-training programme for children and adolescents with cerebral palsy (CP). Method: In this randomised, parallel-group trial with waiting control, 14 participants with CP (six males, eight females; mean age 11y, SD 2y range 9-15y), diagnosed with upper-limb spasticity were…

  9. Adaptation of neuromuscular activation patterns during treadmill walking after long-duration space flight

    NASA Astrophysics Data System (ADS)

    Layne, C. S.; Lange, G. W.; Pruett, C. J.; McDonald, P. V.; Merkle, L. A.; Mulavara, A. P.; Smith, S. L.; Kozlovskaya, I. B.; Bloomberg, J. J.

    The precise neuromuscular control needed for optimal locomotion, particularly around heel strike and toe off, is known to be compromised after short duration (8- to 15-day) space flight. We hypothesized here that longer exposure to weightlessness would result in maladaptive neuromuscular activation during postflight treadmill walking. We also hypothesized that space flight would affect the ability of the sensory-motor control system to generate adaptive neuromuscular activation patterns in response to changes in visual target distance during postflight treadmill walking. Seven crewmembers, who completed 3- to 6-month missions, walked on a motorized treadmill while visually fixating on a target placed 30 cm (NEAR) or 2 m (FAR) from the subject's eyes. Electronic foot switch data and surface electromyography were collected from selected muscles of the right lower limb. Results indicate that the phasic features of neuromuscular activation were moderately affected and the relative amplitude of activity in the tibialis anterior and rectus femoris around toe off changed after space flight. Changes also were evident after space flight in how these muscles adapted to the shift in visual target distance.

  10. Pharyngeal neuromuscular dysfunction associated with bilateral guttural pouch tympany in a foal

    PubMed Central

    Bell, Chris

    2007-01-01

    A 2-month-old warmblood filly was presented for a 1-week history of a large, nonpainful, fluctuant swelling of the parotid and laryngeal area. Bilateral guttural pouch tympany was diagnosed. Surgical correction resolved the guttural pouch tympany; however, postoperative pharyngeal neuromuscular dysfunction developed. PMID:17334035

  11. Pharyngeal neuromuscular dysfunction associated with bilateral guttural pouch tympany in a foal.

    PubMed

    Bell, Chris

    2007-02-01

    A 2-month-old warmblood filly was presented for a 1-week history of a large, nonpainful, fluctuant swelling of the parotid and laryngeal area. Bilateral guttural pouch tympany was diagnosed. Surgical correction resolved the guttural pouch tympany; however, postoperative pharyngeal neuromuscular dysfunction developed. PMID:17334035

  12. Mirror Visual Feedback Induces Lower Neuromuscular Activity in Children with Spastic Hemiparetic Cerebral Palsy

    ERIC Educational Resources Information Center

    Feltham, Max G.; Ledebt, Annick; Deconinck, Frederik J. A.; Savelsbergh, Geert J. P.

    2010-01-01

    The study examined the effects of mirror feedback information on neuromuscular activation during bimanual coordination in eight children with spastic hemiparetic cerebral palsy (SHCP) and a matched control group. The "mirror box" creates a visual illusion, which gives rise to a visual perception of a zero lag, symmetric movement between the two…

  13. Reversal of profound neuromuscular blockade with sugammadex in an infant after bronchial foreign body removal.

    PubMed

    Azizoglu, Mustafa; Birbicer, Handan; Memis, Suleyman; Taşkınlar, Hakan

    2016-09-01

    Sugammadex is a selective chemical agent that can reverse neuromuscular blockade induced by vecuronium and rocuronium. The aim of this report is to discuss the effectiveness of sugammadex in the reversal of neuromuscular blockade in children younger than 2 years. A 16-month-old boy, weighing 10 kg, was admitted to the pediatric emergency department due to choking, cyanosis, and severe respiratory distress that occurred while he was eating peanuts. In the emergency department, the patient's condition deteriorated, and he went into respiratory arrest. He was immediately intubated and taken to the operating room. A rigid bronchoscopy was performed under general anesthesia, with administration of intravenous pentothal (5 mg/kg), rocuronium (0.6 mg/kg), and fentanyl (0.5 μg/kg) in the operating room. The foreign body was removed within 6 minutes, and the profound neuromuscular blockade was reversed with a dose of 2 mg/kg sugammadex. He was extubated successfully after obtaining the spontaneous respiratory activity, and adequate breathing was restored. Clinical use of sugammadex in children younger than 2 years is not recommended because of the lack of clinical studies. In this case report, the profound neuromuscular blockade was successfully reversed with a dose of 2 mg/kg sugammadex in a 16-month-old boy. However, more prospective clinical studies are required for the safe use of this agent in children. PMID:27555184

  14. Enhancement of neuromuscular dynamics and strength behavior using extremely low magnitude mechanical signals in mice.

    PubMed

    Mettlach, Gabriel; Polo-Parada, Luis; Peca, Lauren; Rubin, Clinton T; Plattner, Florian; Bibb, James A

    2014-01-01

    Exercise in general, and mechanical signals in particular, help ameliorate the neuromuscular symptoms of aging and possibly other neurodegenerative disorders by enhancing muscle function. To better understand the salutary mechanisms of such physical stimuli, we evaluated the potential for low intensity mechanical signals to promote enhanced muscle dynamics. The effects of daily brief periods of low intensity vibration (LIV) on neuromuscular functions and behavioral correlates were assessed in mice. Physiological analysis revealed that LIV increased isometric force production in semitendinosus skeletal muscle. This effect was evident in both young and old mice. Isometric force recordings also showed that LIV reduced the fatiguing effects of intensive synaptic muscle stimulation. Furthermore, LIV increased evoked neurotransmitter release at neuromuscular synapses but had no effect on spontaneous end plate potential amplitude or frequency. In behavioral studies, LIV increased mouse grip strength and potentiated initial motor activity in a novel environment. These results provide evidence for the efficacy of LIV in producing changes in the neuromuscular system that translate into performance gains at a behavioral scale.

  15. Neuromuscular adverse effects associated with systemic retinoid dermatotherapy: monitoring and treatment algorithm for clinicians.

    PubMed

    Chroni, Elisabeth; Monastirli, Alexandra; Tsambaos, Dionysios

    2010-01-01

    Although neuromuscular adverse effects represent significant clinical manifestations of hypervitaminosis A syndrome, surprisingly little attention has been paid to the potential neuromuscular toxicity of vitamin A derivatives (retinoids). Since isotretinoin and acitretin are currently the two most commonly used oral retinoids in systemic dermatotherapy, this review focuses exclusively on their neuromuscular adverse effects and proposes a neuromuscular algorithm for appropriate monitoring of patients treated with these two compounds. The most frequent CNS adverse effect associated with oral isotretinoin is headache, either as an independent adverse effect or as part of benign intracranial hypertension, which is additionally characterized by nausea and visual changes. Isolated cases of stiff-person-like syndrome, epileptic seizures and generalized muscle stiffness syndrome, possibly or probably related to oral treatment with isotretinoin, have also been reported. In addition, oral isotretinoin has reportedly been associated with muscular adverse effects that most frequently manifest as myalgia and stiffness and, in rare cases, as true myopathy or rhabdomyolysis. Creatine phosphokinase, a specific marker of muscle destruction, has been found to be elevated, occasionally by up to 100 times the normal value (with or without muscular symptoms and signs), in a variable percentage of patients receiving isotretinoin treatment and particularly in those undergoing vigorous physical exercise. Oral acitretin has been found to cause peripheral nerve dysfunction, particularly of sensory fibres, which in rare cases leads to clinically evident sensory disturbances. Less clear is the causal relationship between acitretin and benign intracranial hypertension or myopathy, whereas an isolated case of cranial nerve IV (oculomotor) palsy and a further case of thrombotic stroke during treatment with oral acitretin have been reported. Systemic diseases with involvement of nervous and

  16. Neuromuscular performance and bone structural characteristics in young healthy men and women.

    PubMed

    Rantalainen, T; Heinonen, A; Komi, P V; Linnamo, V

    2008-01-01

    Muscle mass and strength have been shown to be important factors in bone strength. Low muscular force predisposes to falling especially among elderly. Regular exercise helps to prevent falls and resulting bone fractures. Better understanding of muscle function and its importance on bone properties may thus add information to fracture prevention. Therefore the purpose of this study was to examine the relationship between bone strength and muscular force production. Twenty-young men [24 (2) years] and 20 [24 (3) years] women served as subjects. Bone compressive (BSI(d)) and bending strength indices (50 Imax) were measured with peripheral quantitative computed tomography (pQCT) at tibial mid-shaft and at distal tibia. Ankle plantarflexor muscle volume (MV) was estimated from muscle thickness measured with ultrasonography. Neuromuscular performance was evaluated from the measurements of maximal ground reaction force (GRF) in bilateral jumping and of eccentric maximal voluntary ankle plantarflexor torque (MVC). Specific tension (ST) of the plantarflexors was calculated by dividing the MVC with the muscle volume. Activation level (AL) was measured with superimposed twitch method. Distal tibia BSI(d) and tibial mid-shaft 50 Imax correlated positively with GRF, MVC and MV in men (r = 0.45-0.67, P < 0.05). Tibial mid-shaft 50 Imax and neuromuscular performance variables were correlated in women (r = 0.46-0.59, P < 0.05), whereas no correlation was seen in distal tibia. In the regression analysis, MV and ST could explain 64% of the variance in tibial mid-shaft bone strength and 41% of the variation in distal tibia bone strength. The study emphasizes that tibial strength is related to maximal neuromuscular performance. In addition, tibial mid-shaft seems to be more dependent on the neuromuscular performance, than distal tibia. In young adults, the association between bone adaptation and neuromuscular performance seems to be moderate and also site and loading specific.

  17. Inhibitory system overstimulation plays a role in the pathogenesis of neuromuscular and neurological diseases: a novel hypothesis

    PubMed Central

    Tuk, Bert

    2016-01-01

    Based upon a thorough review of published clinical observations regarding the inhibitory system, I hypothesize that this system may play a key role in the pathogenesis of a variety of neuromuscular and neurological diseases. Specifically, excitatory overstimulation, which is commonly reported in neuromuscular and neurological diseases, may be a homeostatic response to inhibitory overstimulation. Involvement of the inhibitory system in disease pathogenesis is highly relevant, given that most approaches currently being developed for treating neuromuscular and neurological diseases focus on reducing excitatory activity rather than reducing inhibitory activity. PMID:27547379

  18. Overstimulation of the inhibitory nervous system plays a role in the pathogenesis of neuromuscular and neurological diseases: a novel hypothesis

    PubMed Central

    Tuk, Bert

    2016-01-01

    Based upon a thorough review of published clinical observations regarding the inhibitory system, I hypothesize that this system may play a key role in the pathogenesis of a variety of neuromuscular and neurological diseases. Specifically, excitatory overstimulation, which is commonly reported in neuromuscular and neurological diseases, may be a homeostatic response to inhibitory overstimulation. Involvement of the inhibitory system in disease pathogenesis is highly relevant, given that most approaches currently being developed for treating neuromuscular and neurological diseases focus on reducing excitatory activity rather than reducing inhibitory activity. PMID:27547379

  19. Defects in Neuromuscular Transmission May Underlie Motor Dysfunction in Spinal and Bulbar Muscular Atrophy

    PubMed Central

    Xu, Youfen; Halievski, Katherine; Henley, Casey; Atchison, William D.; Katsuno, Masahisa; Adachi, Hiroaki; Sobue, Gen; Breedlove, S. Marc

    2016-01-01

    Spinal and bulbar muscular atrophy (SBMA) in men is an androgen-dependent neuromuscular disease caused by expanded CAG repeats in the androgen receptor (AR). Whether muscle or motor neuron dysfunction or both underlies motor impairment in SBMA is unknown. Muscles of SBMA mice show significant contractile dysfunction, implicating them as a likely source of motor dysfunction, but whether disease also impairs neuromuscular transmission is an open question. Thus, we examined synaptic function in three well-studied SBMA mouse models—the AR97Q, knock-in (KI), and myogenic141 models—by recording in vitro miniature and evoked end-plate potentials (MEPPs and EPPs, respectively) intracellularly from adult muscle fibers. We found striking defects in neuromuscular transmission suggesting that toxic AR in SBMA impairs both presynaptic and postsynaptic mechanisms. Notably, SBMA causes neuromuscular synapses to become weak and muscles to become hyperexcitable in all three models. Presynaptic defects included deficits in quantal content, reduced size of the readily releasable pool, and impaired short-term facilitation. Postsynaptic defects included prolonged decay times for both MEPPs and EPPs, marked resistance to μ-conotoxin (a sodium channel blocker), and enhanced membrane excitability. Quantitative PCR revealed robust upregulation of mRNAs encoding neonatal isoforms of the AChR (γ-subunit) and the voltage-gated sodium channel (NaV1.5) in diseased adult muscles of all three models, consistent with the observed slowing of synaptic potentials and resistance to μ-conotoxin. These findings suggest that muscles of SBMA patients regress to an immature state that impairs neuromuscular function. SIGNIFICANCE STATEMENT We have discovered that SBMA is accompanied by marked defects in neuromuscular synaptic transmission involving both presynaptic and postsynaptic mechanisms. For three different mouse models, we find that diseased synapses are weak, having reduced quantal content

  20. Architectural properties of the neuromuscular compartments in selected forearm skeletal muscles.

    PubMed

    Liu, An-Tang; Liu, Ben-Li; Lu, Li-Xuan; Chen, Gang; Yu, Da-Zhi; Zhu, Lie; Guo, Rong; Dang, Rui-Shan; Jiang, Hua

    2014-07-01

    The purposes f this study were to (i) explore the possibility of splitting the selected forearm muscles into separate compartments in human subjects; (ii) quantify the architectural properties of each neuromuscular compartment; and (iii) discuss the implication of these properties in split tendon transfer procedures. Twenty upper limbs from 10 fresh human cadavers were used in this study. Ten limbs of five cadavers were used for intramuscular nerve study by modified Sihler's staining technique, which confirmed the neuromuscular compartments. The other 10 limbs were included for architectural analysis of neuromuscular compartments. The architectural features of the compartments including muscle weight, muscle length, fiber length, pennation angle, and sarcomere length were determined. Physiological cross-sectional area and fiber length/muscle length ratio were calculated. Five of the selected forearm muscles were ideal candidates for splitting, including flexor carpi ulnaris, flexor carpi radials, extensor carpi radialis brevis, extensor carpi ulnaris and pronator teres. The humeral head of pronator teres contained the longest fiber length (6.23 ± 0.31 cm), and the radial compartment of extensor carpi ulnaris contained the shortest (2.90 ± 0.28 cm). The ulnar compartment of flexor carpi ulnaris had the largest physiological cross-sectional area (5.17 ± 0.59 cm(2)), and the ulnar head of pronator teres had the smallest (0.67 ± 0.06 cm(2)). Fiber length/muscle length ratios of the neuromuscular compartments were relatively low (average 0.27 ± 0.09, range 0.18-0.39) except for the ulnar head of pronator teres, which had the highest one (0.72 ± 0.05). Using modified Sihler's technique, this research demonstrated that each compartment of these selected forearm muscles has its own neurovascular supply after being split along its central tendon. Data of the architectural properties of each neuromuscular compartment provide insight into the 'design' of their

  1. Knee joint biomechanics and neuromuscular control during gait before and after total knee arthroplasty are sex-specific.

    PubMed

    Astephen Wilson, Janie L; Dunbar, Michael J; Hubley-Kozey, Cheryl L

    2015-01-01

    The future of total knee arthroplasty (TKA) surgery will involve planning that incorporates more patient-specific characteristics. Despite known biological, morphological, and functional differences between men and women, there has been little investigation into knee joint biomechanical and neuromuscular differences between men and women with osteoarthritis, and none that have examined sex-specific biomechanical and neuromuscular responses to TKA surgery. The objective of this study was to examine sex-associated differences in knee kinematics, kinetics and neuromuscular patterns during gait before and after TKA. Fifty-two patients with end-stage knee OA (28 women, 24 men) underwent gait and neuromuscular analysis within the week prior to and one year after surgery. A number of sex-specific differences were identified which suggest a different manifestation of end-stage knee OA between the sexes.

  2. An Integrated Approach to Change the Outcome Part II: Targeted Neuromuscular Training Techniques to Reduce Identified ACL Injury Risk Factors

    PubMed Central

    Myer, Gregory D.; Ford, Kevin R.; Brent, Jensen L.; Hewett, Timothy E.

    2014-01-01

    Prior reports indicate that female athletes who demonstrate high knee abduction moments (KAMs) during landing are more responsive to neuromuscular training designed to reduce KAM. Identification of female athletes who demonstrate high KAM, which accurately identifies those at risk for noncontact anterior cruciate ligament (ACL) injury, may be ideal for targeted neuromuscular training. Specific neuromuscular training targeted to the underlying biomechanical components that increase KAM may provide the most efficient and effective training strategy to reduce noncontact ACL injury risk. The purpose of the current commentary is to provide an integrative approach to identify and target mechanistic underpinnings to increased ACL injury in female athletes. Specific neuromuscular training techniques will be presented that address individual algorithm components related to high knee load landing patterns. If these integrated techniques are employed on a widespread basis, prevention strategies for noncontact ACL injury among young female athletes may prove both more effective and efficient. PMID:22580980

  3. Neuromuscular adaptations predict functional disability independently of clinical pain and psychological factors in patients with chronic non-specific low back pain.

    PubMed

    Dubois, Jean-Daniel; Abboud, Jacques; St-Pierre, Charles; Piché, Mathieu; Descarreaux, Martin

    2014-08-01

    Patients with chronic low back pain exhibit characteristics such as clinical pain, psychological symptoms and neuromuscular adaptations. The purpose of this study was to determine the independent contribution of clinical pain, psychological factors and neuromuscular adaptations to disability in patients with chronic low back pain. Clinical pain intensity, pain catastrophizing, fear-avoidance beliefs, anxiety, neuromuscular adaptations to chronic pain and neuromuscular responses to experimental pain were assessed in 52 patients with chronic low back pain. Lumbar muscle electromyographic activity was assessed during a flexion-extension task (flexion relaxation phenomenon) to assess both chronic neuromuscular adaptations and neuromuscular responses to experimental pain during the task. Multiple regressions showed that independent predictors of disability included neuromuscular adaptations to chronic pain (β=0.25, p=0.006, sr(2)=0.06), neuromuscular responses to experimental pain (β=-0.24, p=0.011, sr(2)=0.05), clinical pain intensity (β=0.28, p=0.002, sr(2)=0.08) and psychological factors (β=0.58, p<0.001, sr(2)=0.32). Together, these predictors accounted for 65% of variance in disability (R(2)=0.65 p<0.001). The current investigation revealed that neuromuscular adaptations are independent from clinical pain intensity and psychological factors, and contribute to inter-individual differences in patients' disability. This suggests that disability, in chronic low back pain patients, is determined by a combination of factors, including clinical pain, psychological factors and neuromuscular adaptations.

  4. Maintaining Optimal Surgical Conditions With Low Insufflation Pressures is Possible With Deep Neuromuscular Blockade During Laparoscopic Colorectal Surgery

    PubMed Central

    Kim, Myoung Hwa; Lee, Ki Young; Lee, Kang-Young; Min, Byung-Soh; Yoo, Young Chul

    2016-01-01

    Abstract Carbon dioxide (CO2) absorption and increased intra-abdominal pressure can adversely affect perioperative physiology and postoperative recovery. Deep muscle relaxation is known to improve the surgical conditions during laparoscopic surgery. We aimed to compare the effects of deep and moderate neuromuscular block in laparoscopic colorectal surgery, including intra-abdominal pressure. In this prospective, double-blind, parallel-group trial, 72 adult patients undergoing laparoscopic colorectal surgery were randomized using an online randomization generator to achieve either moderate (1–2 train-of-four response, n = 36) or deep (1–2 post-tetanic count, n = 36) neuromuscular block by receiving a continuous infusion of rocuronium. Adjusted intra-abdominal pressure, which was titrated by a surgeon with maintaining the operative field during pneumoperitoneum, was recorded at 5-minute intervals. Perioperative hemodynamic parameters and postoperative outcomes were assessed. Six patients from the deep and 5 from the moderate neuromuscular block group were excluded, leaving 61 for analysis. The average adjusted IAP was lower in the deep compared to the moderate neuromuscular block group (9.3 vs 12 mm Hg, P < 0.001). The postoperative pain scores (P < 0.001) and incidence of postoperative shoulder tip pain were lower, whereas gas passing time (P = 0.002) and sips of water time (P = 0.005) were shorter in the deep neuromuscular block than in the moderate neuromuscular block group. Deep neuromuscular blocking showed several benefits compared to conventional moderate neuromuscular block, including a greater intra-abdominal pressure lowering effect, whereas surgical conditions are maintained, less severe postoperative pain and faster bowel function recovery. PMID:26945393

  5. Enhancement of Neuromuscular Activity by Natural Specimens and Cultured Mycelia of Cordyceps sinensis in Mice.

    PubMed

    Singh, K P; Meena, H S; Negi, P S

    2014-09-01

    The present study was aimed to evaluate the effect of natural specimen and laboratory cultured mycelia of Cordyceps sinensis on neuromuscular activity in mice. The powder of natural specimen and laboratory cultured Cordyceps sinensis was orally administered at the dose rate of 100, 300 and 500 mg/kg for 30 days. Natural specimen and in vitro propagated Cordyceps sinensis showed significant (P<0.05) enhancement in neuromuscular endurance and antidepressant activity at 300 and 500 mg/kg as compared to the control group. However, the fungus did not proved to be as effective as fluoxetine in exhibiting antidepressant action. Muscular endurance was determined on a Rota rod apparatus while antidepressant (mood elevating) activity was measured on a photoactometer in Swiss albino mice. The effects produced by both natural specimens and laboratory cultured Cordyceps sinensis were comparable and showed almost equal potency.

  6. The use of "stabilization exercises" to affect neuromuscular control in the lumbopelvic region: a narrative review.

    PubMed

    Bruno, Paul

    2014-06-01

    It is well-established that the coordination of muscular activity in the lumbopelvic region is vital to the generation of mechanical spinal stability. Several models illustrating mechanisms by which dysfunctional neuromuscular control strategies may serve as a cause and/or effect of low back pain have been described in the literature. The term "core stability" is variously used by clinicians and researchers, and this variety has led to several rehabilitative approaches suggested to affect the neuromuscular control strategies of the lumbopelvic region (e.g. "stabilization exercise", "motor control exercise"). This narrative review will highlight: 1) the ongoing debate in the clinical and research communities regarding the terms "core stability" and "stabilization exercise", 2) the importance of sub-grouping in identifying those patients most likely to benefit from such therapeutic interventions, and 3) two protocols that can assist clinicians in this process.

  7. [Neuromuscular dynamic scapular winging: Clinical, electromyographic and magnetic resonance imaging diagnosis].

    PubMed

    Nguyen, Christelle; Guérini, Henri; Roren, Alexandra; Zauderer, Jennifer; Vuillemin, Valérie; Seror, Paul; Ouaknine, Michaël; Palazzo, Clémence; Bourdet, Christopher; Pluot, Étienne; Roby-Brami, Agnès; Drapé, Jean-Luc; Rannou, François; Poiraudeau, Serge; Lefèvre-Colau, Marie-Martine

    2015-12-01

    Dyskinesia of the scapula is a clinical diagnosis and includes all disorders affecting scapula positioning and movement whatever its etiology. Scapular winging is a subtype of scapular dyskinesia due to a dynamic prominence of the medial border of the scapula (DSW) secondary to neuromuscular imbalance in the scapulothoracic stabilizer muscles. The two most common causes of DSW are microtraumatic or idiopathic lesions of the long thoracic nerve (that innerves the serratus anterior) or the accessory nerve (that innerves the trapezius). Diagnosis of DSW is clinical and electromyographic. Use of magnetic resonance imaging (MRI) could be of interest to distinguish lesion secondary to a long thoracic nerve from accessory nerve and to rule out scapular dyskinesia related to other shoulder disorders. Causal neuromuscular lesion diagnosis in DSW is challenging. Clinical examinations, combined with scapular MRI, could help to their specific diagnosis, determining their stage, ruling out differential diagnosis and thus give raise to more targeted treatment. PMID:26433832

  8. CLINICAL APPROACH TO THE DIAGNOSTIC EVALUATION OF HERDITARY AND ACQUIRED NEUROMUSCULAR DISEASES

    PubMed Central

    McDonald, Craig M.

    2012-01-01

    SYNOPSIS In the context of a neuromuscular disease diagnostic evaluation, the clinician still must be able to obtain a relevant patient and family history and perform focused general, musculoskeletal, neurologic and functional physical examinations to direct further diagnostic evaluations. Laboratory studies for hereditary neuromuscular diseases include relevant molecular genetic studies. The EMG and nerve conduction studies remain an extension of the physical examination and help to guide further diagnostic studies such as molecular genetic studies, and muscle and nerve biopsies. All diagnostic information needs to be interpreted not in isolation, but within the context of relevant historical information, family history, physical examination findings, and laboratory data, electrophysiologic findings, pathologic findings, and molecular genetic findings if obtained. PMID:22938875

  9. Effects of mescaline and some of its analogs on cholinergic neuromuscular transmission.

    PubMed

    Ghansah, E; Kopsombut, P; Malleque, M A; Brossi, A

    1993-02-01

    Mescaline (3,4,5-trimethoxyphenylethylamine; MES) and its analogs, anhalinine (ANH) and methylenemescaline trimer (MMT) were investigated, using sciatic-sartorius preparations of the frog and cortical tissue from the rat. The effects of MES and its analogs were examined with respect to muscle twitch, resting membrane potential and nicotinic receptor binding. Mescaline and its analogs (10-100 microM) blocked both directly and neurally evoked twitches but their effects on neurally evoked twitches were greater than those on directly evoked twitches. Mescaline, ANH and MMT decreased amplitude of the miniature endplate and endplate potentials, decreased acetylcholine (ACh) quantal content, hyperpolarized the resting membrane potential and prolonged duration of the action potential. They did not significantly displace the binding of [125I]-alpha-bungarotoxin (alpha-BTX) to nicotinic receptors, at concentrations which blocked neuromuscular transmission. These results suggest that MES and its analogs inhibit cholinergic neuromuscular transmission by blocking release of ACh; they also affect K+ conductance.

  10. Mixed cholinergic/glutamatergic neuromuscular innervation of Onychophora: a combined histochemical/electrophysiological study.

    PubMed

    Stern, Michael; Bicker, Gerd

    2008-08-01

    Morphological and molecular phylogenetic data show that the Onychophora are close relatives of the Arthropoda. However, onychophoran neuromuscular junctions have been reported to employ acetylcholine, as in annelids, nematodes, and other bilaterians, rather than glutamate, as in arthropods. Here, we show that the large longitudinal muscles of Peripatoides respond indeed only to acetylcholine, whereas the oblique and ring muscles of the body wall are sensitive both to acetylcholine and to L-glutamate. Moreover, cytochemical staining reveals both acetylcholinesterase- and glutamate-positive synaptic boutons on oblique and ring muscles. These novel findings agree with a phylogenetic position of onychophorans basal to that of the arthropods. Although the glutamatergic phenotype of excitatory neuromuscular transmission may be a characteristic feature of arthropods and present even in a subset of onychophoran motor neurons, the motor neurons of the longitudinal muscles still retain the cholinergic phenotype typical for annelids and other taxa. PMID:18563449

  11. 2-O-substituted cyclodextrins as reversal agents for the neuromuscular blocker rocuronium bromide.

    PubMed

    Tarver, Gary J; Grove, Simon J A; Buchanan, Kirsteen; Bom, Anton; Cooke, Andrew; Rutherford, Samantha J; Zhang, Ming Qiang

    2002-06-01

    A series of secondary face modified cyclodextrins (CDs) were synthesised with the aim of constructing host molecules capable of forming host-guest complexes with neuromuscular blockers, especially with rocuronium bromide. Perfacial 2-O-substitution of gamma-CD with 4-carboxybenzyl resulted in a CD host molecule 1 that forms a 1:1 binary complex with rocuronium bromide (K(a) 6.2 x 10(5) M(-1)). The biological activities of this compound and other derivatives as reversal agents of rocuronium bromide were examined in vitro (mouse hemi-diaphragm) and in vivo (anaesthetized guinea pigs). The host molecule 1 was found to exert potent reversal activity (ED(50) 0.21 micromol/kg, iv) against rocuronium-induced neuromuscular block, and thus proved the viability of using host molecules as antidotes of a biologically active compound.

  12. [Neuromuscular dynamic scapular winging: Clinical, electromyographic and magnetic resonance imaging diagnosis].

    PubMed

    Nguyen, Christelle; Guérini, Henri; Roren, Alexandra; Zauderer, Jennifer; Vuillemin, Valérie; Seror, Paul; Ouaknine, Michaël; Palazzo, Clémence; Bourdet, Christopher; Pluot, Étienne; Roby-Brami, Agnès; Drapé, Jean-Luc; Rannou, François; Poiraudeau, Serge; Lefèvre-Colau, Marie-Martine

    2015-12-01

    Dyskinesia of the scapula is a clinical diagnosis and includes all disorders affecting scapula positioning and movement whatever its etiology. Scapular winging is a subtype of scapular dyskinesia due to a dynamic prominence of the medial border of the scapula (DSW) secondary to neuromuscular imbalance in the scapulothoracic stabilizer muscles. The two most common causes of DSW are microtraumatic or idiopathic lesions of the long thoracic nerve (that innerves the serratus anterior) or the accessory nerve (that innerves the trapezius). Diagnosis of DSW is clinical and electromyographic. Use of magnetic resonance imaging (MRI) could be of interest to distinguish lesion secondary to a long thoracic nerve from accessory nerve and to rule out scapular dyskinesia related to other shoulder disorders. Causal neuromuscular lesion diagnosis in DSW is challenging. Clinical examinations, combined with scapular MRI, could help to their specific diagnosis, determining their stage, ruling out differential diagnosis and thus give raise to more targeted treatment.

  13. Loss of motoneuron-specific microRNA-218 causes systemic neuromuscular failure.

    PubMed

    Amin, Neal D; Bai, Ge; Klug, Jason R; Bonanomi, Dario; Pankratz, Matthew T; Gifford, Wesley D; Hinckley, Christopher A; Sternfeld, Matthew J; Driscoll, Shawn P; Dominguez, Bertha; Lee, Kuo-Fen; Jin, Xin; Pfaff, Samuel L

    2015-12-18

    Dysfunction of microRNA (miRNA) metabolism is thought to underlie diseases affecting motoneurons. One miRNA, miR-218, is abundantly and selectively expressed by developing and mature motoneurons. Here we show that mutant mice lacking miR-218 die neonatally and exhibit neuromuscular junction defects, motoneuron hyperexcitability, and progressive motoneuron cell loss, all of which are hallmarks of motoneuron diseases such as amyotrophic lateral sclerosis and spinal muscular atrophy. Gene profiling reveals that miR-218 modestly represses a cohort of hundreds of genes that are neuronally enriched but are not specific to a single neuron subpopulation. Thus, the set of messenger RNAs targeted by miR-218, designated TARGET(218), defines a neuronal gene network that is selectively tuned down in motoneurons to prevent neuromuscular failure and neurodegeneration.

  14. Neuromuscular Junctions as Key Contributors and Therapeutic Targets in Spinal Muscular Atrophy

    PubMed Central

    Boido, Marina; Vercelli, Alessandro

    2016-01-01

    Spinal muscular atrophy (SMA) is a recessive autosomal neuromuscular disease, representing the most common fatal pediatric pathology. Even though, classically and in a simplistic way, it is categorized as a motor neuron (MN) disease, there is an increasing general consensus that its pathogenesis is more complex than expected. In particular, neuromuscular junctions (NMJs) are affected by dramatic alterations, including immaturity, denervation and neurofilament accumulation, associated to impaired synaptic functions: these abnormalities may in turn have a detrimental effect on MN survival. Here, we provide a description of NMJ development/maintenance/maturation in physiological conditions and in SMA, focusing on pivotal molecules and on the time-course of pathological events. Moreover, since NMJs could represent an important target to be exploited for counteracting the pathology progression, we also describe several therapeutic strategies that, directly or indirectly, aim at NMJs. PMID:26869891

  15. Increased Asynchronous Release and Aberrant Calcium Channel Activation in Amyloid Precursor Protein Deficient Neuromuscular Synapses

    PubMed Central

    Yang, Li; Wang, Baiping; Long, Cheng; Wu, Gangyi; Zheng, Hui

    2007-01-01

    Despite the critical roles of the amyloid precursor protein (APP) in Alzheimer's disease pathogenesis, its physiological function remains poorly established. Our previous studies implicated a structural and functional activity of the APP family of proteins in the developing neuromuscular junction (NMJ). Here we performed comprehensive analyses of neurotransmission in mature neuromuscular synapse of APP deficient mice. We found that APP deletion led to reduced paired-pulse facilitation and increased depression of synaptic transmission with repetitive stimulation. Readily releasable pool size and total releasable vesicles were not affected, but probability of release was significantly increased. Strikingly, the amount of asynchronous release, a measure sensitive to presynaptic calcium concentration, was dramatically increased, and pharmacological studies revealed that it was attributed to aberrant activation of N- and L-type Ca2+ channels. We propose that APP modulates synaptic transmission at the NMJ by ensuring proper Ca2+ channel function. PMID:17919826

  16. Resistance training improves capacity to delay neuromuscular fatigue in older adults.

    PubMed

    Emerson, Nadia S; Stout, Jeffrey R; Fukuda, David H; Robinson, Edward H; Iv; Scanlon, Tyler C; Beyer, Kyle S; Fragala, Maren S; Hoffman, Jay R

    2015-01-01

    The purpose of this study was to investigate the effects of short term resistance exercise on neuromuscular fatigue threshold (PWCFT), strength, functional performance, and body composition in older adults. Twenty-three participants (71.2 ± 6.0 yr) were randomly assigned to 6 weeks of resistance exercise (EXE) or control (CONT). A submaximal cycle ergometer test, physical working capacity at fatigue threshold, was used to determine PWCFT. Strength was assessed with predicted leg extension 1-RM and functional performance with time to complete 5 chair rises (CHAIR) and walk an 8-ft course (WALK). PWCFT, 1-RM and CHAIR significantly (p<0.05) improved in the EXE (27%, 24%, 27%) compared with CONT (-0.1%, 7%, 6%), respectively. The results of this study suggest that short term EXE improved strength, functionality and the capacity to delay the onset of neuromuscular fatigue in older adults.

  17. Mixed cholinergic/glutamatergic neuromuscular innervation of Onychophora: a combined histochemical/electrophysiological study.

    PubMed

    Stern, Michael; Bicker, Gerd

    2008-08-01

    Morphological and molecular phylogenetic data show that the Onychophora are close relatives of the Arthropoda. However, onychophoran neuromuscular junctions have been reported to employ acetylcholine, as in annelids, nematodes, and other bilaterians, rather than glutamate, as in arthropods. Here, we show that the large longitudinal muscles of Peripatoides respond indeed only to acetylcholine, whereas the oblique and ring muscles of the body wall are sensitive both to acetylcholine and to L-glutamate. Moreover, cytochemical staining reveals both acetylcholinesterase- and glutamate-positive synaptic boutons on oblique and ring muscles. These novel findings agree with a phylogenetic position of onychophorans basal to that of the arthropods. Although the glutamatergic phenotype of excitatory neuromuscular transmission may be a characteristic feature of arthropods and present even in a subset of onychophoran motor neurons, the motor neurons of the longitudinal muscles still retain the cholinergic phenotype typical for annelids and other taxa.

  18. The immediate effect of lumbar spine patterns of neuromuscular joint facilitation in young amateur baseball players.

    PubMed

    Huo, Ming; Maruyama, Hitoshi; Kaneko, Takasumi; Naito, Daiki; Koiso, Yuta

    2013-12-01

    [Purpose] The aim of the study was to investigate the changes in baseball pitching velocity, the functional reach test (FR) and the simple reaction times (SRT) in young amateur baseball players after lumbar spine patterns of neuromuscular joint facilitation (NJF) treatment. [Subjects] The subjects were 11 young amateur baseball players. An NJF intervention and a proprioceptive neuromuscular facilitation (PNF) intervention were performed. The interventions were performed one after the other with one week between them. The order of the interventions was completely randomized. [Methods] The baseball pitching velocity, the FR and the SRT were evaluated before and after treatment. [Results] In the NJF group, there were significant differences in baseball pitching velocity, FR and SRT after treatment. In the PNF group, there was a significant difference in SRT after treatment. [Conclusion] NJF intervention shortens the SRT, increases the baseball pitching velocity and FR, and may be recommended to improve performance in baseball players. PMID:24409011

  19. The immediate effect of lumbar spine patterns of neuromuscular joint facilitation in young amateur baseball players.

    PubMed

    Huo, Ming; Maruyama, Hitoshi; Kaneko, Takasumi; Naito, Daiki; Koiso, Yuta

    2013-12-01

    [Purpose] The aim of the study was to investigate the changes in baseball pitching velocity, the functional reach test (FR) and the simple reaction times (SRT) in young amateur baseball players after lumbar spine patterns of neuromuscular joint facilitation (NJF) treatment. [Subjects] The subjects were 11 young amateur baseball players. An NJF intervention and a proprioceptive neuromuscular facilitation (PNF) intervention were performed. The interventions were performed one after the other with one week between them. The order of the interventions was completely randomized. [Methods] The baseball pitching velocity, the FR and the SRT were evaluated before and after treatment. [Results] In the NJF group, there were significant differences in baseball pitching velocity, FR and SRT after treatment. In the PNF group, there was a significant difference in SRT after treatment. [Conclusion] NJF intervention shortens the SRT, increases the baseball pitching velocity and FR, and may be recommended to improve performance in baseball players.

  20. [A new neuromuscular transmission monitor (TOF Guard): the rationale behind the method and its clinical usefulness].

    PubMed

    Ueda, N; Masuda, Y; Muteki, T; Tsuda, H; Hiraki, T; Harada, H; Tobata, H

    1994-01-01

    TOF Guard is one of the latest developments in the field of neuromuscular monitoring equipment. This system uses a miniature acceleration transducer (a piezo-electric ceramic wafer is used), simply fastened to the thumb with tape. The rationale behind the method is Newton's second law, stating that the acceleration is directly proportional to the force. In this study, authors assessed the accuracy of this system in clinical use, comparing with the force transducer method (Myograph 2000). The result showed that there was a very close positive correlation between the values of T1, TOF ratio and posttetanic count simultaneously measured by both methods. The coefficient of correlation was 0.96, and its significance level was P < 0.001. From the clinical view point, it is concluded that TOF Guard is very useful because of its accuracy and because the equipment is easy to handle, compact and of low price as a neuromuscular monitoring system for routine anesthesia.

  1. Effects of Short- and Long-Duration Space Flight on Neuromuscular Function

    NASA Technical Reports Server (NTRS)

    Buxton, Roxanne E.; Spiering, Barry A.; Ryder, Jeffrey W.; Ploutz-Snyder, Lori L.; Bloomberg, Jacob J.

    2010-01-01

    The Functional Task Tests (FTT) is an interdisciplinary study designed to correlate the changes in functional tasks (such as emergency egress, ladder climbing, and hatch opening) with changes in neuromuscular, cardiovascular, and sensorimotor function. One aspect of the FTT, the neuromuscular function test, is used to investigate the neuromuscular component underlying changes in the ability of astronauts to perform functional tasks (representative of critical mission tasks) safely and quickly after flight. PURPOSE: To describe neuromuscular function after short- and long-duration space flight. METHODS: To date, 5 crewmembers on short-duration (10- to 15-day) missions and 3 on long-duration missions have participated. Crewmembers were assessed 30 days before flight, on landing day (short-duration subjects only) and 1, 6, and 30 days after landing. The interpolated twitch technique, which utilizes a combination of maximal voluntary contractions and electrically evoked contractions, was used to assess the maximal voluntary isometric force (MIF) and central activation capacity of the knee extensors. Leg-press and bench-press devices were used to assess MIF and maximal dynamic power of the lower and upper body respectively. Specifically, power was measured during concentric-only ballistic throws of the leg-press sled and bench-press bar loaded to 40% and 30% of MIF respectively. RESULTS: Data are currently being collected from both Shuttle and ISS crewmembers. Emerging data indicate that measures of knee extensor muscle function are decreased with long-duration flight. DISCUSSION: The relationships between flight duration, neural drive, and muscle performance are of particular interest. Ongoing research will add to the current sample size and will focus on defining changes in muscle performance measures after long-duration space flight.

  2. [Muscle relaxants and neuromuscular monitoring - Introduction for a safe clinical application].

    PubMed

    Döcker, Dennis; Walther, Andreas

    2012-05-01

    The use of muscle relaxants facilitates endotracheal intubation and ameliorates the conditions of surgery. But, their use should be controlled - otherwise there will be postoperative residual curarisation which can lead to patient discomfort up to severe medical complications. Therefore, an appropriate surveillance via objective neuromuscular monitoring is essential. This article gives a review of the basic principles of muscle relaxants, their clinical application and the surveillance of their effects and degradation.

  3. Preferences of Mexican anesthesiologists for vecuronium, rocuronium, or other neuromuscular blocking agents: a survey

    PubMed Central

    Nava-Ocampo, A A; Ramírez-Mora, J C; Moyao-García, D; Garduño-Espinosa, J; Salmerón, J

    2002-01-01

    Background Several neuromuscular blocking (NMB) agents are available for clinical use in anesthesia. The present study was performed in order to identify preferences and behaviors of anesthesiologists for using vecuronium, rocuronium or other NMB agents in their clinical practice. Material and methods The cross-sectional survey was applied at the Updated Course of the Colegio Mexicano de Anestesiología performed last year. Of 989, 282 (28.5%) surveys were returned. Results Most anesthesiologists were working at both public and private hospitals, performed anesthetic procedures for hospitalized and ambulatory patients, and anesthetized children as well as adults. Respondents did not consider mechanomyography as the gold standard method for neuromuscular monitoring. The T25 was not recognized as a pharmacodynamic parameter that represents the clinical duration of the neuromuscular block. Most answered that vecuronium induces less histamine release than rocuronium, had never used any neuromuscular monitor, did not know the cost of vecuronium and rocuronium, and preferred rocuronium in multiple-sampling vials and vecuronium in either a vial for single or multiple sampling. Rocuronium was preferred for emergency surgery in patients with full stomach only. Almost all of anesthesiologists that conserve the unused drug did it without refrigeration and more than 30% conserve the unused drug in one syringe for further use. Conclusion Vecuronium was preferred for most clinical situations, and the decision for this choice was not based on costs. Storage of unused drugs without refrigeration in a single syringe for purpose of future use in several patients represented a dangerous common practice. PMID:11991809

  4. Magnesium-induced recurarisation after reversal of rocuronium-induced neuromuscular block with sugammadex.

    PubMed

    Unterbuchner, C; Ziegleder, R; Graf, B; Metterlein, T

    2015-04-01

    A 61-year-old woman (57 kg, 171 cm) underwent surgery under general anaesthesia with desflurane 5.8-6.1 vol. % end-tidal, remifentanil 0.2-0.4 μg/kg/min and rocuronium 35 mg (0.61 mg/kg). On return of the second twitch in the train-of-four (TOF) stimulation measured by acceleromyography, sugammadex 120 mg (2.1 mg/kg) was given. After complete neuromuscular recovery, magnesium sulphate 3600 mg (60 mg/kg) was injected intravenously over 5 min to treat atrial fibrillation. This was associated with recurarisation with a nadir [first twitch=25%, TOF ratio (TOFR)=67%] 7 min after the start of the magnesium sulphate infusion (magnesium plasma level: 2.67 mM). A spontaneous twitch value and a TOFR of >90% were observed 45 min after the beginning of the magnesium sulphate infusion under general anaesthesia. Rapid infusion of magnesium sulphate may re-establish a sugammadex-reversed, rocuronium-induced neuromuscular block during general anaesthesia, probably because of the high plasma level of magnesium (2.67 mM). Desflurane and a small fraction of unbound rocuronium may amplify the known muscle relaxing effects of magnesium. Intravenous injection of magnesium sulphate is not recommended in patients after general anaesthesia with neuromuscular relaxants, particularly after sugammadex reversal. Quantitative neuromuscular monitoring should be used for reversing aminosteroid muscle relaxants with sugammadex--particularly in combination with magnesium injection--to prevent post-operative residual curarisation.

  5. [Muscle relaxants and neuromuscular monitoring - Introduction for a safe clinical application].

    PubMed

    Döcker, Dennis; Walther, Andreas

    2012-05-01

    The use of muscle relaxants facilitates endotracheal intubation and ameliorates the conditions of surgery. But, their use should be controlled - otherwise there will be postoperative residual curarisation which can lead to patient discomfort up to severe medical complications. Therefore, an appropriate surveillance via objective neuromuscular monitoring is essential. This article gives a review of the basic principles of muscle relaxants, their clinical application and the surveillance of their effects and degradation. PMID:22628025

  6. Reactive Neuromuscular Training for the Anterior Cruciate Ligament-Deficient Knee: A Case Report

    PubMed Central

    Cook, Gray; Burton, Lee; Fields, Keith

    1999-01-01

    Objective: To demonstrate the response to a proprioceptive training model during a 1-week rehabilitation regime. The techniques were demonstrated on a college-aged female basketball player who had injured her anterior cruciate ligament (ACL) several weeks earlier. The athlete was tested, trained, and then retested during her semester break. Background: The ACL injury has become a fairly common occurrence in the world of athletics. Knowing this, the athletic trainer is constantly searching for ways to improve the rehabilitative process. New research demonstrates that rehabilitation should be based on proprioception. The ACL not only serves a mechanical role by limiting passive knee mobility but also serves a sensory role through the mechanoreceptors deep in its tissue, which communicate with the neuromuscular system to provide proprioceptive feedback during training and competition. Differential Diagnosis: Partial or complete tear of the ACL. Treatment: The athlete was treated with a rehabilitation protocol based on proprioception, which uses reactive neuromuscular training. Uniqueness: Our rehabilitation focused on the muscular imbalances about the hip, knee, and ankle. The athlete achieved dramatic decreases in muscular imbalances about the hip and knee in only 1 week of rehabilitation through reactive neuromuscular training. Conclusions: The athlete had significant gains in strength over her brief period of therapy. However, these gains can be viewed only as neuromuscular changes and not strictly as gains in strength. The athlete returned to postseason competition under the supervision of her surgeon, who later recommended surgical reconstruction at the completion of the basketball season with rehabilitation during the offseason. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5.Figure 6.Figure 7.Figure 8.Figure 9.Figure 10.Figure 11.Figure 12. PMID:16558562

  7. Single leg jumping neuromuscular control is improved following whole body, long-axis rotational training.

    PubMed

    Nyland, John; Burden, Robert; Krupp, Ryan; Caborn, David N M

    2011-04-01

    Improved lower extremity neuromuscular control during sports may decrease injury risk. This prospective study evaluated progressive resistance, whole body, long-axis rotational training on the Ground Force 360 device. Our hypothesis was that device training would improve lower extremity neuromuscular control based on previous reports of kinematic, ground reaction force (GRF) or electromyographic (EMG) evidence of safer or more efficient dynamic knee stability during jumping. Thirty-six healthy subjects were randomly assigned to either training (Group 1) or control (Group 2) groups. Using a pre-test, post-test study design data were collected from three SLVJ trials. Unpaired t-tests with adjustments for multiple comparisons were used to evaluate group mean change differences (P≤0.05/25≤0.002). During propulsion Group 1 standardized EMG amplitude mean change differences for gluteus maximus (-21.8% vs. +17.4%), gluteus medius (-28.6% vs. +15.0%), rectus femoris (-27.1% vs. +11.2%), vastus medialis (-20.2% vs. +9.1%), and medial hamstrings (-38.3% vs. +30.3%) differed from Group 2. During landing Group 1 standardized EMG amplitude mean change differences for gluteus maximus (-32.9% vs. +11.1%) and rectus femoris (-33.3% vs. +29.0%) also differed from Group 2. Group 1 peak propulsion vertical GRF (+0.24N/kg vs. -0.46N/kg) and landing GRF stabilization timing (-0.68 vs. +0.05s) mean change differences differed from Group 2. Group 1 mean hip (-16.3 vs. +7.8°/s) and knee (-21.4 vs. +18.5°/s) flexion velocity mean change differences also differed from Group 2. Improved lower extremity neuromuscular efficiency, increased peak propulsive vertical GRF, decreased mean hip and knee flexion velocities during landing, and earlier landing stabilization timing in the training group suggests improved lower extremity neuromuscular control.

  8. Comparative investigation of the pharmacology of fish and mammalian neuromuscular systems

    SciTech Connect

    Gant, D.B.

    1985-01-01

    Neuromuscular pharmacology has been extensively studied in mammals but there have been few investigations examining the neuromuscular systems of fish. In situ experiments have shown that the basic cholinergic characteristics of fish neuromuscular junctions are different from those of mammals. In order to further understand the nature of these differences, the nicotinic acetylcholine receptors (AChR) of rat and buffalo sculpin (Enophrys bison) neuromuscular junctions and the AChR of electric ray (Torpedo california) electroplax, were investigated using receptor binding analysis. A rapid filtration assay was utilized to measure (/sup 125/I)..cap alpha..-BGT binding to tissue membranes. Scatchard analysis of (/sup 175/I)..cap alpha..-BGT binding was performed on sculpin pectoral muscle rat gastrocnemius, rat denervated gastrocnemius, and Torpedo electroplax. The affinity constant was similar for all tissues studied. In competition studies, d-tubocurarine had the highest affinity for the (/sup 125/I)-..cap alpha..-BGT binding site in all tissues, illustrating the nicotinic nature of the binding sites. Acetylcholine had high affinity for the rat gastrocnemius binding site and low affinity for the sculpin pectoral muscle and Torpedo electroplax binding site. Atropine had high affinity for the sculpin pectoral muscle binding site when compared to the rate gastrocnemius and Torpedo electroplax binding site, indicating that the sculpin pectoral site may have some mixed muscarinic-nicitinic characteristics. These results indicate that there are definite qualitative as well as quantitative differences between the fish skeletal muscle nicotinic receptor and the nicotinic receptor of fish electroplax and rat skeletal muscle.

  9. Test battery designed to quickly and safely assess diverse indices of neuromuscular function after unweighting.

    PubMed

    Spiering, Barry A; Lee, Stuart M C; Mulavara, Ajitkumar P; Bentley, Jason R; Buxton, Roxanne E; Lawrence, Emily L; Sinka, Joseph; Guilliams, Mark E; Ploutz-Snyder, Lori L; Bloomberg, Jacob J

    2011-02-01

    Adequately describing the functional consequences of unweighting (e.g., bed rest, immobilization, spaceflight) requires assessing diverse indices of neuromuscular function (i.e., strength, power, endurance, central activation, force steadiness). Additionally, because unweighting increases the susceptibility of muscle to damage, testing should consider supplementary safety features. The purpose of this study was to develop a test battery for quickly assessing diverse indices of neuromuscular function. Commercially available exercise equipment was modified to include data acquisition hardware (e.g., force plates, position transducers) and auxiliary safety hardware (e.g., magnetic brakes). Ten healthy, ambulatory subjects (31 ± 5 years, 173 ± 11 cm, 73 ± 14 kg) completed a battery of lower- and upper-body neuromuscular function tests on 3 occasions separated by at least 48 hours. The battery consisted of the following tests, in order: (1) knee extension central activation, (2) knee extension force steadiness, (3) leg press maximal strength, (4) leg press maximal power, (5) leg press power endurance, (6) bench press maximal strength, (7) bench press force steadiness, (8) bench press maximal power, and (9) bench press power endurance. Central activation, strength, rate of force development, maximal power, and power endurance (total work) demonstrated good-to-excellent measurement reliability (SEM = 3-14%; intraclass correlation coefficient [ICC] = 0.87-0.99). The SEM of the force steadiness variables was 20-35% (ICC = 0.20-0.60). After familiarization, the test battery required 49 ± 6 minutes to complete. In conclusion, we successfully developed a test battery that could be used to quickly and reliably assess diverse indices of neuromuscular function. Because the test battery involves minimal eccentric muscle actions and impact forces, the potential for muscle injury has likely been reduced.

  10. HIV-related neuromuscular diseases: nemaline myopathy, amyotrophic lateral sclerosis and bibrachial amyotrophic diplegia.

    PubMed

    Rowland, L P

    2011-06-01

    The human immunodeficiency virus (HIV) causes diverse disorders of the brain, spinal cord and peripheral nerves. Rarely, polymyositis and myoglobinuria are seen. Two other neuromuscular syndromes in people with HIV antibodies are nemaline myopathy and bibrachial amyotrophic diplegia, a form of motor neuron disease. The associations between these diseases and the possibility that HIV infection could be a risk factor for either amyotrophic lateral sclerosis (ALS) itself or other motor neuron diseases are investigated. PMID:21842590

  11. Does quadriceps neuromuscular activation capability explain walking speed in older men and women?

    PubMed

    Clark, David J; Reid, Kieran F; Patten, Carolynn; Phillips, Edward M; Ring, Sarah A; Wu, Samuel S; Fielding, Roger A

    2014-07-01

    Age-related impairment of neuromuscular activation has been shown to contribute to weakness in older adults. However, it is unclear to what extent impaired neuromuscular activation independently accounts for decline of mobility function. The hypothesis of this study is that the capability to produce rapid neuromuscular activation during maximal effort leg muscle contractions will be shown to be an independent predictor of mobility function in older men and women after accounting for muscle size and adiposity, body composition and age. Twenty six older men and eighteen older women (aged 70-85years) participated in this study. Mobility function was assessed by the 400-m walk test. Neuromuscular activation of the quadriceps muscle group was assessed by surface electromyography ("rate of EMG rise"). Thigh muscle cross sectional area and adiposity were assessed by computed tomography. In males, univariate regression analysis revealed strong associations between walking speed and a number of predictors including age (p<0.01), muscle area (p<0.01), intermuscular adipose tissue area (p<0.01), and rate of EMG rise (p<0.001). Subsequent multiple regression analysis with all variables accounted for 72% of the variability in walking speed (p<.0001), with age and rate of EMG rise as the dominant variables in the model. In females, univariate analysis showed a significant association only between walking speed and subcutaneous adipose tissue area (p<0.05). Multiple regression analysis accounted for only 44% of the variability in walking speed, and was not statistically significant (p=0.18). The present findings indicate that the capability to rapidly activate the quadriceps muscle group is an important factor accounting for inter-individual variability of walking speed among older men, but not among older women. This research is important for informing the design of assessments and interventions that seek to detect and prevent impairments that contribute to age-related mobility

  12. Neuromuscular Effects of Common Krait (Bungarus caeruleus) Envenoming in Sri Lanka

    PubMed Central

    Silva, Anjana; Maduwage, Kalana; Sedgwick, Michael; Pilapitiya, Senaka; Weerawansa, Prasanna; Dahanayaka, Niroshana J.; Buckley, Nicholas A.; Johnston, Christopher; Siribaddana, Sisira; Isbister, Geoffrey K.

    2016-01-01

    Objective We aimed to investigate neurophysiological and clinical effects of common krait envenoming, including the time course and treatment response. Methodology Patients with definite common krait (Bungarus caeruleus) bites were recruited from a Sri Lankan hospital. All patients had serial neurological examinations and stimulated concentric needle single-fibre electromyography (sfEMG) of orbicularis oculi in hospital at 6wk and 6–9mth post-bite. Principal Findings There were 33 patients enrolled (median age 35y; 24 males). Eight did not develop neurotoxicity and had normal sfEMG. Eight had mild neurotoxicity with ptosis, normal sfEMG; six received antivenom and all recovered within 20–32h. Seventeen patients developed severe neurotoxicity with rapidly descending paralysis, from ptosis to complete ophthalmoplegia, facial, bulbar and neck weakness. All 17 received Indian polyvalent antivenom a median 3.5h post-bite (2.8–7.2h), which cleared unbound venom from blood. Despite this, the paralysis worsened requiring intubation and ventilation within 7h post-bite. sfEMG showed markedly increased jitter and neuromuscular blocks within 12h. sfEMG abnormalities gradually improved over 24h, corresponding with clinical recovery. Muscle recovery occurred in ascending order. Myotoxicity was not evident, clinically or biochemically, in any of the patients. Patients were extubated a median 96h post-bite (54–216h). On discharge, median 8 days (4–12days) post-bite, patients were clinically normal but had mild sfEMG abnormalities which persisted at 6wk post-bite. There were no clinical or neurophysiological abnormalities at 6–9mth. Conclusions Common krait envenoming causes rapid onset severe neuromuscular paralysis which takes days to recover clinically consistent with sfEMG. Subclinical neuromuscular dysfunction lasts weeks but was not permanent. Antivenom effectively cleared venom but did not prevent worsening or reverse neuromuscular paralysis. PMID:26829229

  13. Effects of in vivo injury on the neuromuscular junction in healthy and dystrophic muscles

    PubMed Central

    Pratt, Stephen JP; Shah, Sameer B; Ward, Christopher W; Inacio, Mario P; Stains, Joseph P; Lovering, Richard M

    2013-01-01

    The most common and severe form of muscular dystrophy is Duchenne muscular dystrophy (DMD), a disorder caused by the absence of dystrophin, a structural protein found on the cytoplasmic surface of the sarcolemma of striated muscle fibres. Considerable attention has been dedicated to studying myofibre damage and muscle plasticity, but there is little information to determine if damage from contraction-induced injury occurs at or near the nerve terminal axon. We used α-bungarotoxin to compare neuromuscular junction (NMJ) morphology in healthy (wild-type, WT) and dystrophic (mdx) mouse quadriceps muscles and evaluated transcript levels of the post-synaptic muscle-specific kinase signalling complex. Our focus was to study changes in NMJs after injury induced with an established in vivo animal injury model. Neuromuscular transmission, electromyography (EMG), and NMJ morphology were assessed 24 h after injury. In non-injured muscle, muscle-specific kinase expression was significantly decreased in mdx compared to WT. Injury resulted in a significant loss of maximal torque in WT (39 ± 6%) and mdx (76 ± 8%) quadriceps, but significant changes in NMJ morphology, neuromuscular transmission and EMG data were found only in mdx following injury. Compared with WT mice, motor end-plates of mdx mice demonstrated less continuous morphology, more disperse acetylcholine receptor aggregates and increased number of individual acetylcholine receptor clusters, an effect that was exacerbated following injury. Neuromuscular transmission failure increased and the EMG measures decreased after injury in mdx mice only. The data show that eccentric contraction-induced injury causes morphological and functional changes to the NMJs in mdx skeletal muscle, which may play a role in excitation–contraction coupling failure and progression of the dystrophic process. PMID:23109110

  14. Cough augmentation with mechanical insufflation/exsufflation in patients with neuromuscular weakness.

    PubMed

    Chatwin, M; Ross, E; Hart, N; Nickol, A H; Polkey, M I; Simonds, A K

    2003-03-01

    Adults and children with neuromuscular disease exhibit weak cough and are susceptible to recurrent chest infections, a major cause of morbidity and mortality. Mechanical insufflation/exsufflation may improve cough efficacy by increasing peak cough flow. It was hypothesised that mechanical insufflation/exsufflation would produce a greater increase in peak cough flow than other modes of cough augmentation. The acceptability of these interventions was also compared. Twenty-two patients aged 10-56 yrs (median 21 yrs) with neuromuscular disease and 19 age-matched controls were studied. Spirometry was performed and respiratory muscle strength measured. Peak cough flow was recorded during maximal unassisted coughs, followed in random order by coughs assisted by physiotherapy, noninvasive ventilation, insufflation and exsufflation, and exsufflation alone. Subjects rated strength of cough, distress and comfort on a visual analogue scale. In the neuromuscular disease group, mean +/- SD forced expiratory volume in one second was 0.8 +/- 0.6 L x s(-1), forced vital capacity 0.9 +/- 0.8 L, maximum inspiratory pressure 25 +/- 16 cmH2O, maximum expiratory pressure 26 +/- 22 cmH2O and unassisted peak cough flow 169 +/- 90 L x min(-1). The greatest increase in peak cough flow was observed with mechanical insufflation/exsufflation at 235 +/- 111 L x min(-1) (p<0.01). All techniques showed similar patient acceptability. Mechanical insufflation/exsufflation produces a greater increase in peak cough flow than other standard cough augmentation techniques in adults and children with neuromuscular disease.

  15. Studies on neuromuscular blockade by boldine in the mouse phrenic nerve-diaphragm.

    PubMed

    Kang, J J; Cheng, Y W; Fu, W M

    1998-02-01

    The effects of boldine [(S)-2,9-dihydroxyl-1,10-dimethoxy-aporphine], a major alkaloid in the leaves and bark of Boldo (Peumus boldus Mol.), on neuromuscular transmission were studied using a muscle phrenic-nerve diaphragm preparation. Boldine at concentrations lower than 200 microM preferentially inhibited, after an initial period of twitch augmentation, the nerve-evoked twitches of the mouse diaphragm and left the muscle-evoked twitches unaffected. The twitch inhibition could be restored by neostigmine or washout with Krebs solution. The twitches evoked indirectly and directly were both augmented initially, suggesting that the twitch augmentation induced by boldine was myogenic. Boldine inhibited the acetylcholine-induced contraction of denervated diaphragm dose-dependently with an IC50 value of 13.5 microM. At 50 microM, boldine specifically inhibited the amplitude of the miniature end plate potential. In addition, boldine was similar to d-tubocurarine in its action to reverse the neuromuscular blocking action of alpha-bungarotoxin. These results showed that the neuromuscular blockade by boldine on isolated mouse phrenic-nerve diaphragm might be due to its direct interaction with the postsynaptic nicotinic acetylcholine receptor. PMID:9541284

  16. Comparison of electromyography and kinemyography during recovery from non-depolarising neuromuscular blockade.

    PubMed

    Stewart, P A; Freelander, N; Liang, S; Heller, G; Phillips, S

    2014-05-01

    In this study, two commercially available quantitative neuromuscular function monitoring techniques, electromyography (EMG) and kinemyography (KMG), were compared with respect to repeatability and accuracy during late recovery from neuromuscular blockade. Train-of-four (TOF) ratios were recorded in 30 patients using KMG and EMG at the adductor pollicis muscle. Measurements were taken on the same hand using the Datex-Ohmeda NeuroMuscular Transmission monitor (GE Healthcare, Helsinki, Finland). Instrumental precision was evaluated using the coefficient of repeatability, while accuracy was assessed using the bias and limits of agreement. The coefficients of repeatability were similar for both techniques (0.035 for KMG and 0.043 for EMG), indicating a similar level of precision. KMG overestimated the TOF ratios measured with EMG with a bias of 0.11 (95% limits of agreement: -0.13 to 0.35). At a TOF ratio of 0.90 the bias was 0.08 (95% limits of agreement: -0.08 to 0.25). This means that at a TOF ratio of 0.90 measured with KMG will be approximately equivalent to a TOF ratio of 0.80 measured with EMG at the adductor pollicis muscle, but it may indeed be as low as 0.65 or as high as 1.00. Therefore, TOF ratios measured by KMG and EMG cannot be used interchangeably.

  17. Rapid synthesis of acetylcholine receptors at neuromuscular junctions. (Reannouncement with new availability information)

    SciTech Connect

    Ramsay, D.A.; Drachman, D.B.; Pestronk, A.

    1988-12-31

    The rate of acetylcholine receptor (AChR) degradation in mature, innervated mammalian neuromuscular junctions has recently been shown to be biphasic; up to 20% are rapidly turned over whereas the remainder are lost more slowly. In order to maintain normal junctional receptor density, synthesis and insertion of AChRs should presumably be sufficiently rapid to replace both the RTOs and the stable receptors. The authors have tested this prediction by blocking pre-existing AChRs in the mouse sternomastoid muscle with alpha bungarotoxin and monitoring the subsequent appearance of new junctional AChRs at intervals of 3 h to 20 days by labelling them. The results show that new receptors were initially inserted rapidly. The rate of increase of new binding sites gradually slowed down during the remainder of the time period studied. Control observations excluded possible artifacts of the experimental procedure including incomplete blockade of AChRs, dissociation of toxin receptor complexes, or experimentally induced alteration of receptor synthesis. The present demonstration of rapid synthesis and incorporation of AChRs at innervated neuromuscular junctions provides support for the concept of a subpopulation of rapidly turned over AChRs. The RTOs may serve as precursors for the large population of stable receptors and have an important role in the metabolism of the neuromuscular synapse.

  18. Physiological control of elaborate male courtship: Female choice for neuromuscular systems

    PubMed Central

    Fusani, Leonida; Barske, Julia; Day, Lainy D.; Fuxjager, Matthew J.; Schlinger, Barney A.

    2015-01-01

    Males of many animal species perform specialized courtship behaviours to gain copulations with females. Identifying physiological and anatomical specializations underlying performance of these behaviours helps clarify mechanisms through which sexual selection promotes the evolution of elaborate courtship. Our knowledge about neuromuscular specializations that support elaborate displays is limited to a few model species. In this review, we focus on the physiological control of the courtship of a tropical bird, the golden-collared manakin, which has been the focus of our research for nearly 20 years. Male manakins perform physically elaborate courtship displays that are quick, accurate and powerful. Females seem to choose males based on their motor skills suggesting that neuromuscular specializations possessed by these males are driven by female choice. Male courtship is activated by androgens and androgen receptors are expressed in qualitatively and quantitatively unconventional ways in manakin brain, spinal cord and skeletal muscles. We propose that in some species, females select males based on their neuromuscular capabilities and acquired skills and that elaborate steroid-dependent courtship displays evolve to signal these traits. PMID:25086380

  19. Physiological control of elaborate male courtship: female choice for neuromuscular systems.

    PubMed

    Fusani, Leonida; Barske, Julia; Day, Lainy D; Fuxjager, Matthew J; Schlinger, Barney A

    2014-10-01

    Males of many animal species perform specialized courtship behaviours to gain copulations with females. Identifying physiological and anatomical specializations underlying performance of these behaviours helps clarify mechanisms through which sexual selection promotes the evolution of elaborate courtship. Our knowledge about neuromuscular specializations that support elaborate displays is limited to a few model species. In this review, we focus on the physiological control of the courtship of a tropical bird, the golden-collared manakin, which has been the focus of our research for nearly 20 years. Male manakins perform physically elaborate courtship displays that are quick, accurate and powerful. Females seem to choose males based on their motor skills suggesting that neuromuscular specializations possessed by these males are driven by female choice. Male courtship is activated by androgens and androgen receptors are expressed in qualitatively and quantitatively unconventional ways in manakin brain, spinal cord and skeletal muscles. We propose that in some species, females select males based on their neuromuscular capabilities and acquired skills and that elaborate steroid-dependent courtship displays evolve to signal these traits. PMID:25086380

  20. Neuromuscular onset succession of high level gymnasts during dynamic leg acceleration phases on high bar.

    PubMed

    von Laßberg, Christoph; Rapp, Walter; Mohler, Betty; Krug, Jürgen

    2013-10-01

    In several athletic disciplines there is evidence that for generating the most effective acceleration of a specific body part the transfer of momentum should run in a "whip-like" consecutive succession of body parts towards the segment which shall be accelerated most effectively (e.g. the arm in throwing disciplines). This study investigated the question how this relates to the succession of neuromuscular activation to induce such "whip like" leg acceleration in sports like gymnastics with changed conditions concerning the body position and momentary rotational axis of movements (e.g. performing giant swings on high bar). The study demonstrates that during different long hang elements, performed by 12 high level gymnasts, the succession of the neuromuscular activation runs primarily from the bar (punctum fixum) towards the legs (punctum mobile). This demonstrates that the frequently used teaching instruction, first to accelerate the legs for a successful realization of such movements, according to a high level kinematic output, is contradictory to the neuromuscular input patterns, being used in high level athletes, realizing these skills with high efficiency. Based on these findings new approaches could be developed for more direct and more adequate teaching methods regarding to an earlier optimization and facilitation of fundamental movement requirements.

  1. Minimally Invasive Scoliosis Surgery: A Novel Technique in Patients with Neuromuscular Scoliosis

    PubMed Central

    Sarwahi, Vishal; Amaral, Terry; Wendolowski, Stephen; Gecelter, Rachel; Gambassi, Melanie; Plakas, Christos; Liao, Benita; Kalantre, Sarika; Katyal, Chhavi

    2015-01-01

    Minimally invasive surgery (MIS) has been described in the treatment of adolescent idiopathic scoliosis (AIS) and adult scoliosis. The advantages of this approach include less blood loss, shorter hospital stay, earlier mobilization, less tissue disruption, and relatively less pain. However, despite these significant benefits, MIS approach has not been reported in neuromuscular scoliosis patients. This is possibly due to concerns with longer surgery time, which is further increased due to more levels fused and instrumented, challenges of pelvic fixation, size and number of incisions, and prolonged anesthesia. We modified the MIS approach utilized in our AIS patients to be implemented in our neuromuscular patients. Our technique allows easy passage of contoured rods, placement of pedicle screws without image guidance, partial/complete facet resection, and all standard reduction maneuvers. Operative time needed to complete this surgery is comparable to the standard procedure and the majority of our patients have been extubated at the end of procedure, spending 1 day in the PICU and 5-6 days in the hospital. We feel that MIS is not only a feasible but also a superior option in patients with neuromuscular scoliosis. Long-term results are unavailable; however, short-term results have shown multiple benefits of this approach and fewer limitations. PMID:26649305

  2. Conservative treatment of neuromuscular scoliosis in adult tetraplegia: a case report.

    PubMed

    Hastings, Jennifer D; Dickson, Julie; Tracy, Linsey; Baniewich, Christine; Levine, Cedar

    2014-12-01

    We report successful correction of new onset neuromuscular scoliosis without spinal surgery in a man who is 30-years post-American Spinal Injury Association Impairment Scale grade A C6 injury with new onset of left neuromuscular scoliosis (Cobb angle 45°) after a motor vehicle collision. Interventions included nightly low-load prolonged stretching (LLPS) (4h left side lying over bolster), a series of 6 botulinum toxin injections (BTIs) at 3-month intervals, and progressive seating adjustments to counteract the spinal curvature. Monthly seating adjustments included rear quadrant wedging, lateral supports, and hip blocking to promote erect and symmetrical posture. A normative Cobb angle (5°) was achieved after 8 months of treatment. Improvements in alignment were demonstrated in physical examination outcome measures at the final session and follow-up. LLPS, seating adjustments, and paraspinal BTI are nonsurgical options for treating neuromuscular scoliosis in adults with tetraplegia. Further studies are necessary to determine optimum protocols and examine generalizability of these treatment methods.

  3. Comparison of the Capacity of Different Jump and Sprint Field Tests to Detect Neuromuscular Fatigue.

    PubMed

    Gathercole, Rob J; Sporer, Ben C; Stellingwerff, Trent; Sleivert, Gord G

    2015-09-01

    Different jump and sprint tests have been used to assess neuromuscular fatigue, but the test with optimal validity remains to be established. The current investigation examined the suitability of vertical jump (countermovement jump [CMJ], squat jump [SJ], drop jump [DJ]) and 20-m sprint (SPRINT) testing for neuromuscular fatigue detection. On 6 separate occasions, 11 male team-sport athletes performed 6 CMJ, SJ, DJ, and 3 SPRINT trials. Repeatability was determined on the first 3 visits, with subsequent 3 visits (0-, 24-, and 72-hour postexercise) following a fatiguing Yo-Yo running protocol. SPRINT performance was most repeatable (mean coefficient of variation ≤2%), whereas DJ testing (4.8%) was significantly less repeatable than CMJ (3.0%) and SJ (3.5%). Each test displayed large decreases at 0-hour (33 of 49 total variables; mean effect size = 1.82), with fewer and smaller decreases at 24-hour postexercise (13 variables; 0.75), and 72-hour postexercise (19 variables; 0.78). SPRINT displayed the largest decreases at 0-hour (3.65) but was subsequently unchanged, whereas SJ performance recovered by 72-hour postexercise. In contrast, CMJ and DJ performance displayed moderate (12 variables; 1.18) and small (6 variables; 0.53) reductions at 72-hour postexercise, respectively. Consequently, the high repeatability and immediate and prolonged fatigue-induced changes indicated CMJ testing as most suitable for neuromuscular fatigue monitoring. PMID:26308829

  4. The effects of whirlpool bath and neuromuscular electrical stimulation on complex regional pain syndrome.

    PubMed

    Devrimsel, Gul; Turkyilmaz, Aysegul Kucukali; Yildirim, Murat; Beyazal, Munevver Serdaroglu

    2015-01-01

    [Purpose] The aim of the present study was to investigate and compare the effects of whirlpool bath and neuromuscular electrical stimulation on complex regional pain syndrome. [Subjects and Methods] Sixty outpatients (30 per group) with complex regional pain syndrome participated. They received 15 treatment 5 days per week for 3 weeks. The outcome measures were the visual analogue scale for pain, edema, range of motion of the wrist (flexion and extension), fingertip-to-distal palmar crease distance, hand grip strength, and pinch strength. All parameters were measured at baseline (week 0) and at the trial end (week 3). [Results] There were significant improvements in all parameters after therapy in both groups. The whirlpool bath group showed significantly better improvements in the visual analogue score, hand edema, hand grip strength, wrist range of motion (both flexion and extension), fingertip-to-distal palmar crease distance, and the three-point and fingertip pinch strengths than the neuromuscular electrical stimulation group; however, the lateral pinch strengths were similar. [Conclusion] Both whirlpool bath and neuromuscular electrical stimulation are effective in the treatment of complex regional pain syndrome, but the efficacy of the whirlpool bath treatment was better.

  5. Neuromuscular fatigue recovery following rapid and slow stretch-shortening cycle movements.

    PubMed

    Wadden, Katie P; Button, Duane C; Kibele, Armin; Behm, David G

    2012-06-01

    The purpose of this study was to investigate underlying mechanisms and neuromuscular recovery patterns following rapid and slow stretch-shortening cycle (SSC) movements performed to fatigue. Fourteen (10 moderately trained (MT) and four highly trained (HT)) subjects completed rapid and slow SSC movements to fatigue. The rapid SSC movement consisted of continuous drop jumps from a 30 cm platform until a predetermined jump height was no longer maintained, and the slow SSC movement consisted of continuous squats to 90° of knee flexion at a load of 65% of subject's one-repetition maximum until no further repetitions could be completed. Although blood lactate measures were significantly (p < 0.002) higher after the rapid SSC condition versus after the slow SSC condition, the recovery of neuromuscular properties (maximum voluntary contractions, twitch force, muscle compound action potential) following the two conditions to fatigue did not differ. The duration of the rapid SSC movement was dependent on the training status of the subject; HT subjects performed the rapid SSC longer (68.2%) than the MT subjects until fatigued. Thus, the neuromuscular fatigue recovery patterns were independent of the type of SSC movement, condition duration, and subject training status. Because rapid and slow SSC exercises induce similar fatigue patterns, training programs incorporating rapid SSC exercises can be developed similar to that prescribed in traditional slow SSC resistance training programs.

  6. Increased quantal release of acetylcholine at the neuromuscular junction following scald injury in the rat.

    PubMed

    Edwards, J P; Hatton, P A; Little, R A; Pennington, R A; Wareham, A C

    1999-12-01

    Following severe burns, patients frequently develop a profound resistance to nondepolarizing neuromuscular blockers. Several mechanisms have been proposed to account for this, including upregulation of nicotinic acetylcholine receptors. We investigated the effects of a 30% body surface area (BSA) scald on neuromuscular transmission in slow-twitch soleus (SOL) and fast-twitch extensor digitorum longus (EDL) of rats. Rats were sacrificed 72 h after the injury, a time at which sepsis is unlikely and body weight gain and core temperature have returned to normal. Further groups of rats were sham operated and either pair fed to the scalded rats or freely fed to assess the influence of food restriction. When compared with muscle from pair-fed control rats, scald resulted in an almost 50% increase in miniature endplate potential (mEPP) frequency in both SOL and EDL. However, scald did not increase mean mEPP amplitude in SOL, although it did cause a 10% increase in EDL. Scald injury did produce a significant increase in the size of the evoked endplate potential in SOL (33%) and EDL (37%). These data indicate that a significant increase in the quantal content of evoked transmitter released in SOL (38%) and EDL (30%) occurred by 72 h after scald. Such an increase may contribute to the resistance to nondepolarizing neuromuscular blockers documented in patients following thermal injury.

  7. Telemedicine system for the care of patients with neuromuscular disease and chronic respiratory failure

    PubMed Central

    Morete, Emilio; González, Francisco

    2014-01-01

    Introduction Neuromuscular diseases cause a number of limitations which may be improved by using a telemedicine system. These include functional impairment and dependence associated with muscle weakness, the insidious development of respiratory failure and episodes of exacerbation. Material and methods The present study involved three patients with severe neuromuscular disease, chronic respiratory failure and long-term mechanical ventilation, who were followed up using a telemedicine platform. The telemedicine system is based on videoconferencing and telemonitoring of cardiorespiratory variables (oxygen saturation, heart rate, blood pressure and electrocardiogram). Two different protocols were followed depending on whether the patient condition was stable or unstable. Results Over a period of 5 years, we analyzed a series of variables including use of the system, patient satisfaction and clinical impact. Overall we performed 290 videoconference sessions, 269 short monitoring oximetry measurements and 110 blood pressure measurements. With respect to the clinical impact, after enrolment in the telemedicine program, the total number of hospital admissions fell from 18 to 3. Conclusions Our findings indicate that the system was user friendly for patients and care givers. Patient satisfaction scores were acceptable. The telemedicine system was effective for the home treatment of three patients with severe neuromuscular diseases and reduced the need for hospital admissions. PMID:25395959

  8. Quantitative neuromuscular ultrasound in intensive care unit-acquired weakness: A systematic review.

    PubMed

    Bunnell, Aaron; Ney, John; Gellhorn, Alfred; Hough, Catherine L

    2015-11-01

    Intensive care unit-acquired weakness (ICU-AW) causes significant morbidity and impairment in critically ill patients. Recent advances in neuromuscular ultrasound (NMUS) allow evaluation of neuromuscular pathology early in critical illness. Here we review application of ultrasound in ICU-AW. MEDLINE-indexed articles were searched for terms relevant to ultrasound and critical illness. Two reviewers evaluated the resulting abstracts (n = 218) and completed full-text review (n = 13). Twelve studies and 1 case report were included. Ten studies evaluated muscle thickness or cross-sectional area (CSA): 8 reported a decrease, and 2 reported no change. Two studies reported preservation of muscle thickness in response to neuromuscular electrical stimulation, and 1 found no preservation. One study found decreases in gray-scale standard deviation, but no change in echogenicity. One study described increases in echogenicity and fasciculations. Ultrasound reliability in ICU-AW is not fully established. Further investigation is needed to identify ultrasound measures that reliably predict clinical, electrodiagnostic, and pathologic findings of ICU-AW.

  9. Lumbar hyperlordosis of neuromuscular origin: pathophysiology and surgical strategy for correction

    PubMed Central

    Khouri, Nejib; Glorion, Christophe; Lechevallier, Joël; Morin, Christian

    2006-01-01

    Lumbar hyperlordosis of neuromuscular origin is rare and requires surgical treatment in order to preserve a good sitting posture. We report twenty-seven cases of a preponderantly sagittal hyperlordosis deformity of the lumbar spine in patients with neuromuscular disorders and identify the indications and results of treatment. Seventeen males and ten females, aged 13 to 27 years, underwent operations for a lumbar hyperlordosis of neuromuscular origin responsible for major difficulties in sitting. In all patients, the sacrum was horizontal and associated in twenty-six cases with marked pelvic anteversion. Eleven patients were treated surgically by a posterior approach. The sixteen remaining patients had a preliminary discectomy, followed by posterior correction and fusion. Lumbar hyperlordosis was reduced from 8° to 77° between L1 and S1. The horizontal sacrum was partially reduced with an improvement from 8° to 50°. Consequently, patients recovered a comfortable sitting position. One patient died of respiratory complications six weeks after surgery. Surgical correction is a demanding procedure which can be performed by a posterior approach. It is mandatory to analyse the spino-pelvic balance to avoid iliac retroversion and the loss of the role of the ischia in the sitting position. PMID:16967278

  10. Loss of Glial Neurofascin155 Delays Developmental Synapse Elimination at the Neuromuscular Junction

    PubMed Central

    Roche, Sarah L.; Sherman, Diane L.; Dissanayake, Kosala; Soucy, Geneviève; Desmazieres, Anne; Lamont, Douglas J.; Peles, Elior; Julien, Jean-Pierre; Wishart, Thomas M.; Ribchester, Richard R.; Brophy, Peter J.

    2014-01-01

    Postnatal synapse elimination plays a critical role in sculpting and refining neural connectivity throughout the central and peripheral nervous systems, including the removal of supernumerary axonal inputs from neuromuscular junctions (NMJs). Here, we reveal a novel and important role for myelinating glia in regulating synapse elimination at the mouse NMJ, where loss of a single glial cell protein, the glial isoform of neurofascin (Nfasc155), was sufficient to disrupt postnatal remodeling of synaptic circuitry. Neuromuscular synapses were formed normally in mice lacking Nfasc155, including the establishment of robust neuromuscular synaptic transmission. However, loss of Nfasc155 was sufficient to cause a robust delay in postnatal synapse elimination at the NMJ across all muscle groups examined. Nfasc155 regulated neuronal remodeling independently of its canonical role in forming paranodal axo–glial junctions, as synapse elimination occurred normally in mice lacking the axonal paranodal protein Caspr. Rather, high-resolution proteomic screens revealed that loss of Nfasc155 from glial cells was sufficient to disrupt neuronal cytoskeletal organization and trafficking pathways, resulting in reduced levels of neurofilament light (NF-L) protein in distal axons and motor nerve terminals. Mice lacking NF-L recapitulated the delayed synapse elimination phenotype observed in mice lacking Nfasc155, suggesting that glial cells regulate synapse elimination, at least in part, through modulation of the axonal cytoskeleton. Together, our study reveals a glial cell-dependent pathway regulating the sculpting of neuronal connectivity and synaptic circuitry in the peripheral nervous system. PMID:25232125

  11. Loss of glial neurofascin155 delays developmental synapse elimination at the neuromuscular junction.

    PubMed

    Roche, Sarah L; Sherman, Diane L; Dissanayake, Kosala; Soucy, Geneviève; Desmazieres, Anne; Lamont, Douglas J; Peles, Elior; Julien, Jean-Pierre; Wishart, Thomas M; Ribchester, Richard R; Brophy, Peter J; Gillingwater, Thomas H

    2014-09-17

    Postnatal synapse elimination plays a critical role in sculpting and refining neural connectivity throughout the central and peripheral nervous systems, including the removal of supernumerary axonal inputs from neuromuscular junctions (NMJs). Here, we reveal a novel and important role for myelinating glia in regulating synapse elimination at the mouse NMJ, where loss of a single glial cell protein, the glial isoform of neurofascin (Nfasc155), was sufficient to disrupt postnatal remodeling of synaptic circuitry. Neuromuscular synapses were formed normally in mice lacking Nfasc155, including the establishment of robust neuromuscular synaptic transmission. However, loss of Nfasc155 was sufficient to cause a robust delay in postnatal synapse elimination at the NMJ across all muscle groups examined. Nfasc155 regulated neuronal remodeling independently of its canonical role in forming paranodal axo-glial junctions, as synapse elimination occurred normally in mice lacking the axonal paranodal protein Caspr. Rather, high-resolution proteomic screens revealed that loss of Nfasc155 from glial cells was sufficient to disrupt neuronal cytoskeletal organization and trafficking pathways, resulting in reduced levels of neurofilament light (NF-L) protein in distal axons and motor nerve terminals. Mice lacking NF-L recapitulated the delayed synapse elimination phenotype observed in mice lacking Nfasc155, suggesting that glial cells regulate synapse elimination, at least in part, through modulation of the axonal cytoskeleton. Together, our study reveals a glial cell-dependent pathway regulating the sculpting of neuronal connectivity and synaptic circuitry in the peripheral nervous system. PMID:25232125

  12. Comparison of the Capacity of Different Jump and Sprint Field Tests to Detect Neuromuscular Fatigue.

    PubMed

    Gathercole, Rob J; Sporer, Ben C; Stellingwerff, Trent; Sleivert, Gord G

    2015-09-01

    Different jump and sprint tests have been used to assess neuromuscular fatigue, but the test with optimal validity remains to be established. The current investigation examined the suitability of vertical jump (countermovement jump [CMJ], squat jump [SJ], drop jump [DJ]) and 20-m sprint (SPRINT) testing for neuromuscular fatigue detection. On 6 separate occasions, 11 male team-sport athletes performed 6 CMJ, SJ, DJ, and 3 SPRINT trials. Repeatability was determined on the first 3 visits, with subsequent 3 visits (0-, 24-, and 72-hour postexercise) following a fatiguing Yo-Yo running protocol. SPRINT performance was most repeatable (mean coefficient of variation ≤2%), whereas DJ testing (4.8%) was significantly less repeatable than CMJ (3.0%) and SJ (3.5%). Each test displayed large decreases at 0-hour (33 of 49 total variables; mean effect size = 1.82), with fewer and smaller decreases at 24-hour postexercise (13 variables; 0.75), and 72-hour postexercise (19 variables; 0.78). SPRINT displayed the largest decreases at 0-hour (3.65) but was subsequently unchanged, whereas SJ performance recovered by 72-hour postexercise. In contrast, CMJ and DJ performance displayed moderate (12 variables; 1.18) and small (6 variables; 0.53) reductions at 72-hour postexercise, respectively. Consequently, the high repeatability and immediate and prolonged fatigue-induced changes indicated CMJ testing as most suitable for neuromuscular fatigue monitoring.

  13. Comparing targeted exome and whole exome approaches for genetic diagnosis of neuromuscular disorders

    PubMed Central

    Gorokhova, Svetlana; Cerino, Mathieu; Mathieu, Yves; Courrier, Sébastien; Desvignes, Jean-Pierre; Salgado, David; Béroud, Christophe; Krahn, Martin; Bartoli, Marc

    2015-01-01

    Massively parallel sequencing is rapidly becoming a widely used method in genetic diagnostics. However, there is still no clear consensus as to which approach can most efficiently identify the pathogenic mutations carried by a given patient, while avoiding false negative and false positive results. We developed a targeted exome approach (MyoPanel2) in order to optimize genetic diagnosis of neuromuscular disorders. Using this approach, we were able to analyse 306 genes known to be mutated in myopathies as well as in related disorders, obtaining 98.8% target sequence coverage at 20 ×. Moreover, MyoPanel2 was able to detect 99.7% of 11,467 known mutations responsible for neuromuscular disorders. We have then used several quality control parameters to compare performance of the targeted exome approach with that of whole exome sequencing. The results of this pilot study of 140 DNA samples suggest that targeted exome sequencing approach is an efficient genetic diagnostic test for most neuromuscular diseases. PMID:27054082

  14. Role of extracellular matrix proteins and their receptors in the development of the vertebrate neuromuscular junction.

    PubMed

    Singhal, Neha; Martin, Paul T

    2011-11-01

    The vertebrate neuromuscular junction (NMJ) remains the best-studied model for understanding the mechanisms involved in synaptogenesis, due to its relatively large size, its simplicity of patterning, and its unparalleled experimental accessibility. During neuromuscular development, each skeletal myofiber secretes and deposits around its extracellular surface an assemblage of extracellular matrix (ECM) proteins that ultimately form a basal lamina. This is also the case at the NMJ, where the motor nerve contributes additional factors. Before most of the current molecular components were known, it was clear that the synaptic ECM of adult skeletal muscles was unique in composition and contained factors sufficient to induce the differentiation of both pre- and postsynaptic membranes. Biochemical, genetic, and microscopy studies have confirmed that agrin, laminin (221, 421, and 521), collagen IV (α3-α6), collagen XIII, perlecan, and the ColQ-bound form of acetylcholinesterase are all synaptic ECM proteins with important roles in neuromuscular development. The roles of their many potential receptors and/or binding proteins have been more difficult to assess at the genetic level due to the complexity of membrane interactions with these large proteins, but roles for MuSK-LRP4 in agrin signaling and for integrins, dystroglycan, and voltage-gated calcium channels in laminin-dependent phenotypes have been identified. Synaptic ECM proteins and their receptors are involved in almost all aspects of synaptic development, including synaptic initiation, topography, ultrastructure, maturation, stability, and transmission. PMID:21766463

  15. LDL-receptor-related protein 4 is crucial for formation of the neuromuscular junction.

    PubMed

    Weatherbee, Scott D; Anderson, Kathryn V; Niswander, Lee A

    2006-12-01

    Low-density lipoprotein receptor-related protein 4 (Lrp4) is a member of a family of structurally related, single-pass transmembrane proteins that carry out a variety of functions in development and physiology, including signal transduction and receptor-mediated endocytosis. Lrp4 is expressed in multiple tissues in the mouse, and is important for the proper development and morphogenesis of limbs, ectodermal organs, lungs and kidneys. We show that Lrp4 is also expressed in the post-synaptic endplate region of muscles and is required to form neuromuscular synapses. Lrp4-mutant mice die at birth with defects in both presynaptic and postsynaptic differentiation, including aberrant motor axon growth and branching, a lack of acetylcholine receptor and postsynaptic protein clustering, and a failure to express postsynaptic genes selectively by myofiber synaptic nuclei. Our data show that Lrp4 is required during the earliest events in postsynaptic neuromuscular junction (NMJ) formation and suggest that it acts in the early, nerveindependent steps of NMJ assembly. The identification of Lrp4 as a crucial factor for NMJ formation may have implications for human neuromuscular diseases such as myasthenia syndromes. PMID:17119023

  16. The Knockdown of αkap Alters the Postsynaptic Apparatus of Neuromuscular Junctions in Living Mice

    PubMed Central

    Martinez-Pena y Valenzuela, Isabel; Aittaleb, Mohamed; Chen, Po-Ju

    2015-01-01

    A muscle-specific nonkinase anchoring protein (αkap), encoded within the calcium/calmodulin kinase II (camk2) α gene, was recently found to control the stability of acetylcholine receptor (AChR) clusters on the surface of cultured myotubes. However, it remains unknown whether this protein has any effect on receptor stability and the maintenance of the structural integrity of neuromuscular synapses in vivo. By knocking down the endogenous expression of αkap in mouse sternomastoid muscles with shRNA, we found that the postsynaptic receptor density was dramatically reduced, the turnover rate of receptors at synaptic sites was significantly increased, and the insertion rates of both newly synthesized and recycled receptors into the postsynaptic membrane were depressed. Moreover, we found that αkap shRNA knockdown impaired synaptic structure as postsynaptic AChR clusters and their associated postsynaptic scaffold proteins within the neuromuscular junction were completely eliminated. These results provide new mechanistic insight into the role of αkap in regulating the stability of the postsynaptic apparatus of neuromuscular synapses. PMID:25834039

  17. Requirement of enhanced Survival Motoneuron protein imposed during neuromuscular junction maturation

    PubMed Central

    Kariya, Shingo; Obis, Teresa; Garone, Caterina; Akay, Turgay; Sera, Fusako; Iwata, Shinichi; Homma, Shunichi; Monani, Umrao R.

    2014-01-01

    Spinal muscular atrophy is a common motor neuron disease caused by low survival motoneuron (SMN), a key protein in the proper splicing of genes. Restoring the protein is therefore a promising therapeutic strategy. Implementation of this strategy, however, depends on defining the temporal requirements for SMN. Here, we used controlled knockdown of SMN in transgenic mice to determine the precise postnatal stage requirements for this protein. Reducing SMN in neonatal mice resulted in a classic SMA-like phenotype. Unexpectedly, depletion of SMN in adults had relatively little effect. Insensitivity to low SMN emerged abruptly at postnatal day 17, which coincided with establishment of the fully mature neuromuscular junction (NMJ). Mature animals depleted of SMN eventually exhibited evidence of selective neuromuscular pathology that was made worse by traumatic injury. The ability to regenerate the mature NMJ in aged or injured SMN-depleted mice was grossly impaired, a likely consequence of the inability to meet the surge in demand for motoneuronal SMN that was seen in controls. Our results demonstrate that relative maturity of the NMJ determines the temporal requirement for the SMN protein. These observations suggest that the use of potent but potentially deleterious SMN-enhancing agents could be tapered in human patients once the neuromuscular system matures and reintroduced as needed to enhance SMN for remodeling aged or injured NMJs. PMID:24463453

  18. Variation in neuromuscular activity during prey capture by trophic specialists and generalists (Pisces: Labridae).

    PubMed

    Sanderson, S L

    1988-01-01

    Members of the marine teleost family Labridae are among the most abundant and morphologically diverse fish on coral reefs. A quantitative analysis was conducted of the neuromuscular activity patterns controlling movement of the jaws during prey capture by 4 labrid species ranging from trophic specialists to trophic generalists. A total of more than 800 captures of 3 prey types was analyzed. All 4 species showed significant modulation of electromyographic parameters in response to different prey types. Significant variation was also found between replicate experiments on the same individuals. To obtain valid assessments of interspecific variability, statistical analyses must take into account this potentially high degree of intraspecific variability. By partitioning the variance in a nested analysis of variance, a lack of significant differences in electromyographic parameters between species became apparent. In contrast to the closely related Cichlidae, trophic diversification in the Labridae has not been accompanied by the acquisition of unique neuromuscular activity patterns for prey capture. The dramatic adaptive radiation that has occurred in these 2 families has involved different processes of evolutionary diversification. Neuromuscular stereotypy of labrids may be associated with the lack of structural flexibility in their 'coupled jaw'. Additional study is needed to establish the extent to which labrid radiation into various trophic niches is related to the evolution of specialized morphologies and foraging behaviors.

  19. Neuromuscular Evaluation With Single-Leg Squat Test at 6 Months After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Hall, Michael P.; Paik, Ronald S.; Ware, Anthony J.; Mohr, Karen J.; Limpisvasti, Orr

    2015-01-01

    Background: Criteria for return to unrestricted activity after anterior cruciate ligament (ACL) reconstruction varies, with some using time after surgery as the sole criterion—most often at 6 months. Patients may have residual neuromuscular deficits, which may increase the risk of ACL injury. A single-leg squat test (SLST) can dynamically assess for many of these deficits prior to return to unrestricted activity. Hypothesis: A significant number of patients will continue to exhibit neuromuscular deficits with SLST at 6 months after ACL reconstruction. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Patients using a standardized accelerated rehabilitation protocol at their 6-month follow-up after primary ACL reconstruction were enrolled. Evaluation included bilateral SLST, single-leg hop distance, hip abduction strength, and the subjective International Knee Documentation Committee (IKDC) score. Results: Thirty-three patients were enrolled. Poor performance of the operative leg SLST was found in 15 of 33 patients (45%). Of those 15 patients, 7 (45%) had concomitant poor performance of the nonoperative leg compared with 2 of 18 patients (11%) in those who demonstrated good performance in the operative leg. The poor performers were significantly older (33.6 years) than the good performers (24.2 years) (P = .007). Those with poor performance demonstrated decreased hip abduction strength (17.6 kg operative leg vs 20.5 kg nonoperative leg) (P = .024), decreased single-leg hop distance (83.3 cm operative leg vs 112.3 cm nonoperative leg) (P = .036), and lower IKDC scores (67.9 vs 82.3) (P = .001). Conclusion: Nearly half of patients demonstrated persistent neuromuscular deficits on SLST at 6 months, which is when many patients return to unrestricted activity. Those with poor performance were of a significantly older age, decreased hip abduction strength, decreased single-leg hop distance, and lower IKDC subjective scores. Clinical Relevance: The SLST

  20. Caffeine Ingestion Reverses the Circadian Rhythm Effects on Neuromuscular Performance in Highly Resistance-Trained Men

    PubMed Central

    Mora-Rodríguez, Ricardo; Pallarés, Jesús García; López-Samanes, Álvaro; Ortega, Juan Fernando; Fernández-Elías, Valentín E.

    2012-01-01

    Purpose To investigate whether caffeine ingestion counteracts the morning reduction in neuromuscular performance associated with the circadian rhythm pattern. Methods Twelve highly resistance-trained men underwent a battery of neuromuscular tests under three different conditions; i) morning (10:00 a.m.) with caffeine ingestion (i.e., 3 mg kg−1; AMCAFF trial); ii) morning (10:00 a.m.) with placebo ingestion (AMPLAC trial); and iii) afternoon (18:00 p.m.) with placebo ingestion (PMPLAC trial). A randomized, double-blind, crossover, placebo controlled experimental design was used, with all subjects serving as their own controls. The neuromuscular test battery consisted in the measurement of bar displacement velocity during free-weight full-squat (SQ) and bench press (BP) exercises against loads that elicit maximum strength (75% 1RM load) and muscle power adaptations (1 m s−1 load). Isometric maximum voluntary contraction (MVCLEG) and isometric electrically evoked strength of the right knee (EVOKLEG) were measured to identify caffeine's action mechanisms. Steroid hormone levels (serum testosterone, cortisol and growth hormone) were evaluated at the beginning of each trial (PRE). In addition, plasma norepinephrine (NE) and epinephrine were measured PRE and at the end of each trial following a standardized intense (85% 1RM) 6 repetitions bout of SQ (POST). Results In the PMPLAC trial, dynamic muscle strength and power output were significantly enhanced compared with AMPLAC treatment (3.0%–7.5%; p≤0.05). During AMCAFF trial, muscle strength and power output increased above AMPLAC levels (4.6%–5.7%; p≤0.05) except for BP velocity with 1 m s−1 load (p = 0.06). During AMCAFF, EVOKLEG and NE (a surrogate of maximal muscle sympathetic nerve activation) were increased above AMPLAC trial (14.6% and 96.8% respectively; p≤0.05). Conclusions These results indicate that caffeine ingestion reverses the morning neuromuscular declines in highly resistance

  1. Biomechanical and neuromuscular characteristics of male athletes: implications for the development of anterior cruciate ligament injury prevention programs.

    PubMed

    Sugimoto, Dai; Alentorn-Geli, Eduard; Mendiguchía, Jurdan; Samuelsson, Kristian; Karlsson, Jon; Myer, Gregory D

    2015-06-01

    Prevention of anterior cruciate ligament (ACL) injury is likely the most effective strategy to reduce undesired health consequences including reconstruction surgery, long-term rehabilitation, and pre-mature osteoarthritis occurrence. A thorough understanding of mechanisms and risk factors of ACL injury is crucial to develop effective prevention programs, especially for biomechanical and neuromuscular modifiable risk factors. Historically, the available evidence regarding ACL risk factors has mainly involved female athletes or has compared male and female athletes without an intra-group comparison for male athletes. Therefore, the principal purpose of this article was to review existing evidence regarding the investigation of biomechanical and neuromuscular characteristics that may imply aberrant knee kinematics and kinetics that would place the male athlete at risk of ACL injury. Biomechanical evidence related to knee kinematics and kinetics was reviewed by different planes (sagittal and frontal/coronal), tasks (single-leg landing and cutting), situation (anticipated and unanticipated), foot positioning, playing surface, and fatigued status. Neuromuscular evidence potentially related to ACL injury was reviewed. Recommendations for prevention programs for ACL injuries in male athletes were developed based on the synthesis of the biomechanical and neuromuscular characteristics. The recommendations suggest performing exercises with multi-plane biomechanical components including single-leg maneuvers in dynamic movements, reaction to and decision making in unexpected situations, appropriate foot positioning, and consideration of playing surface condition, as well as enhancing neuromuscular aspects such as fatigue, proprioception, muscle activation, and inter-joint coordination.

  2. What Is the Evidence for Harm of Neuromuscular Blockade and Corticosteroid Use in the Intensive Care Unit?

    PubMed

    Annane, Djillali

    2016-02-01

    Neuromuscular blocking agents and corticosteroids are widely used in medicine and in particular in the intensive care unit (ICU). Neuromuscular blockade is commonly used to ease tracheal intubation, to optimize mechanical ventilation and oxygenation in acute respiratory disorders such as status asthmaticus and acute respiratory distress syndrome (ARDS), to prevent shivering during therapeutic hypothermia, and also in patients with elevated intracranial pressure. In the ICU, patients with sepsis, ARDS, community-acquired pneumonia, exacerbation of chronic obstructive pulmonary disease, severe asthma, or trauma may receive corticosteroids. It is not rare that ICU patients receive concomitantly neuromuscular blocking drugs and corticosteroids. Among the various serious adverse reactions to these drugs, secondary infection and ICU-acquired weakness may place a burden to the health-care system by resulting in substantial cost and long-term morbidity. Both superinfections and ICU-acquired paresis are more likely when high doses of fluorinated corticosteroids are combined with prolonged treatment with a long-acting non-depolarizing neuromuscular blocker. Modern ICU practices favor lower dose of corticosteroids and very short course of short-acting curare for the management of sepsis or ARDS. Recent trials provided no evidence for increased risk of secondary infections or critical illness neuromyopathy in patients with sepsis or ARDS with the use of corticosteroids or neuromuscular blockers. PMID:26820274

  3. On the role, inactivation and origin of endogenous adenosine at the frog neuromuscular junction.

    PubMed Central

    Ribeiro, J A; Sebastião, A M

    1987-01-01

    1. The effects of adenosine deaminase, inosine, alkylxanthines (8-phenyltheophylline (8-PT), theophylline and isobutylmethylxanthine (IBMX], dipyridamole, alpha, beta-methylene ADP (AOPCP) and ATP analogues (alpha, beta-methylene ATP and beta, gamma-methylene ATP) on evoked end-plate potentials (e.p.p.s) were investigated in innervated sartorius muscles of the frog, in which twitches had been prevented with tubocurarine. The effects of 8-PT and IBMX on the amplitude and quantal content of e.p.p.s were also investigated in innervated sartorius muscles of the frog, in which twitches had been prevented with high-magnesium solutions. 2. Adenosine deaminase reversibly increased the amplitude of e.p.p.s and prevented the reduction caused by exogenously applied adenosine on e.p.p. amplitude. The increase caused by adenosine deaminase was equivalent to the decrease caused by 12 +/- 5.8 microM-adenosine on e.p.p. amplitude. 3. Inosine, the product of adenosine deamination, was virtually devoid of effect on e.p.p.s. 4. The adenosine receptor antagonists at the frog neuromuscular junction, 8-PT and theophylline, increased in a concentration-dependent manner the amplitude of e.p.p.s in the presence of tubocurarine. 8-PT increased the amplitude and quantal content of e.p.p.s in the presence of high magnesium. IBMX, which does not behave as an adenosine receptor antagonist at the frog neuromuscular junction, decreased the amplitude of e.p.p.s in the presence of tubocurarine or high-magnesium solutions. 5. Dipyridamole, an adenosine uptake blocker, decreased the amplitude of e.p.p.s, and in a concentration that did not affect neuromuscular transmission potentiated the depressing effect of adenosine, but not that of 2-chloroadenosine, on the amplitude of e.p.p.s. 6. AOPCP, an inhibitor of 5'-nucleotidase, increased the amplitude of e.p.p.s and markedly attenuated the depressing effect of ATP, but not that of adenosine, on e.p.p. amplitude. 7. The ATP analogue, alpha, beta

  4. Land Analysis System (LAS)

    NASA Technical Reports Server (NTRS)

    Pease, P. B.

    1989-01-01

    Version 4.1 of LAS provides flexible framework for algorithm development and processing and analysis of image data. Over 500,000 lines of code enable image repair, clustering, classification, film processing, geometric registration, radiometric correction, and manipulation of image statistics.

  5. Pathophysiological actions of neuropathy-related anti-ganglioside antibodies at the neuromuscular junction

    PubMed Central

    Plomp, Jaap J; Willison, Hugh J

    2009-01-01

    The outer leaflet of neuronal membranes is highly enriched in gangliosides. Therefore, specific neuronal roles have been attributed to this family of sialylated glycosphingolipids, e.g. in modulation of ion channels and transporters, neuronal interaction and recognition, temperature adaptation, Ca2+ homeostasis, axonal growth, (para)node of Ranvier stability and synaptic transmission. Recent developmental, ageing and injury studies on transgenic mice lacking subsets of gangliosides indicate that gangliosides are involved in maintenance rather than development of the nervous system and that ganglioside family members are able to act in a mutually compensatory manner. Besides having physiological functions, gangliosides are the likely antigenic targets of autoantibodies present in Guillain-Barré syndrome (GBS), a group of neuropathies with clinical symptoms of motor- and/or sensory peripheral nerve dysfunction. Antibody binding to peripheral nerves is thought to either interfere with ganglioside function or activate complement, causing axonal damage and thereby disturbed action potential conduction. The presynaptic motor nerve terminal at the neuromuscular junction (NMJ) may be a prominent target because it is highly enriched in gangliosides and lies outside the blood–nerve barrier, allowing antibody access. The ensuing neuromuscular synaptopathy might contribute to the muscle weakness in GBS patients. Several groups, including our own, have studied the effects of anti-ganglioside antibodies in ex vivo and in vivo experimental settings at mouse NMJs. Here, after providing a background overview on ganglioside synthesis, localization and physiology, we will review those studies, which clearly show that anti-ganglioside antibodies are capable of binding to NMJs and thereby can exert a variety of pathophysiological effects. Furthermore, we will discuss the human clinical electrophysiological and histological evidence produced so far of the existence of a neuromuscular

  6. Activity-dependent degeneration of axotomized neuromuscular synapses in WldS mice

    PubMed Central

    Brown, R.; Hynes-Allen, A.; Swan, A.J.; Dissanayake, K.N.; Gillingwater, T.H.; Ribchester, R.R.

    2015-01-01

    Activity and disuse of synapses are thought to influence progression of several neurodegenerative diseases in which synaptic degeneration is an early sign. Here we tested whether stimulation or disuse renders neuromuscular synapses more or less vulnerable to degeneration, using axotomy as a robust trigger. We took advantage of the slow synaptic degeneration phenotype of axotomized neuromuscular junctions in flexor digitorum brevis (FDB) and deep lumbrical (DL) muscles of Wallerian degeneration-Slow (WldS) mutant mice. First, we maintained ex vivo FDB and DL nerve-muscle explants at 32 °C for up to 48 h. About 90% of fibers from WldS mice remained innervated, compared with about 36% in wild-type muscles at the 24-h checkpoint. Periodic high-frequency nerve stimulation (100 Hz: 1 s/100 s) reduced synaptic protection in WldS preparations by about 50%. This effect was abolished in reduced Ca2+ solutions. Next, we assayed FDB and DL innervation after 7 days of complete tetrodotoxin (TTX)-block of sciatic nerve conduction in vivo, followed by tibial nerve axotomy. Five days later, only about 9% of motor endplates remained innervated in the paralyzed muscles, compared with about 50% in 5 day-axotomized muscles from saline-control-treated WldS mice with no conditioning nerve block. Finally, we gave mice access to running wheels for up to 4 weeks prior to axotomy. Surprisingly, exercising WldS mice ad libitum for 4 weeks increased about twofold the amount of subsequent axotomy-induced synaptic degeneration. Together, the data suggest that vulnerability of mature neuromuscular synapses to axotomy, a potent neurodegenerative trigger, may be enhanced bimodally, either by disuse or by hyperactivity. PMID:25617654

  7. A 4-Week Neuromuscular Training Program and Gait Patterns at the Ankle Joint

    PubMed Central

    Coughlan, Garrett; Caulfield, Brian

    2007-01-01

    Context: Previous research into the rehabilitation of ankle sprains has primarily focused on outcome measures that do not replicate functional activities, thus making it difficult to extrapolate the results relative to the weight-bearing conditions under which most ankle sprains occur. Objective: To measure the effects of a training program on gait during walking and running in an active athletic population. Design: Matched-pairs, controlled trial. Setting: University motion analysis laboratory. Patients or Other Participants: Ten subjects from an athletic population (7 healthy, 3 with functional ankle instability: age = 25.8 ± 3.9 years, height = 177.6 ± 6.1 cm, mass = 66.8 ± 7.4 kg) and 10 controls matched for age, sex, activity, and ankle instability (7 healthy, 3 with functional ankle instability: age = 27.4 ± 5.8 years, height = 178.7 ± 10.8 cm, mass = 71.6 ± 10.0 kg). Intervention(s): A 4-week neuromuscular training program undertaken by the treatment group. Main Outcome Measure(s): We measured ankle position and velocity in the frontal (x) and sagittal (y) planes in all subjects during treadmill walking and running for the periods 100 milliseconds before heel strike, at heel strike, and 100 milliseconds after heel strike. Results: A 4-week neuromuscular training program resulted in no significant changes in ankle position or velocity during treadmill walking and running. Conclusions: The mechanisms by which neuromuscular training improves function in normal subjects and those with functional ankle instability do not appear to result in measurable changes in gait kinematics. Our findings raise issues regarding methods of ankle sprain rehabilitation and the measurement of their effectiveness in improving functional activities. Further research in a larger population with functional ankle instability is necessary. PMID:17597944

  8. Changes in masseter muscle trigger points following strain-counterstrain or neuro-muscular technique.

    PubMed

    Ibáñez-García, Jordi; Alburquerque-Sendín, Francisco; Rodríguez-Blanco, Cleofás; Girao, Didac; Atienza-Meseguer, Albert; Planella-Abella, Sergi; Fernández-de-Las Peñas, César

    2009-01-01

    The aim of this study was to compare the immediate effects, on pressure pain sensitivity and active mouth opening, following the application of neuromuscular or strain/counter-strain technique in latent myofascial trigger points (MTrPs) in the masseter muscle. Seventy-one subjects, 34 men and 37 women, aged 20-65 years old, participated in this study. Subjects underwent a screening process to establish the presence of MTrPs in the masseter muscle. Subjects were divided randomly into three groups: group A which was treated with a neuromuscular intervention, group B treated with the strain/counter-strain technique, and group C as control group. Each treatment group received a weekly treatment session during 3 consecutive weeks. Outcomes measures were pressure pain thresholds (PPTs), active mouth opening and local pain (visual analogue scale, VAS) elicited by the application of 2.5kg/cm(2) of pressure over the MTrP. They were captured at baseline and 1 week after discharge by an assessor blinded to the treatment allocation of the subject. The ANOVA found a significant groupxtime interaction (F=25.3; p<0.001) for changes in PPT, changes in active mouth opening (F=10.5; p<0.001), and local pain evoked by 2.5kg/cm(2) of pressure (F=10.1; p<0.001). Within-group effect sizes were large (d>1) for PPT and mouth opening, and moderate for local pain (d<0.7, 0.5) in both intervention groups; but small (d<0.2) for the control group in all outcomes. No significant differences between both intervention groups were found for any outcome (p>0.8). Our results suggest that neuromuscular or strain/counter-strain technique might be employed in the management of latent MTrPs in the masseter muscle.

  9. Direct and indirect measurement of neuromuscular fatigue in Canadian football players.

    PubMed

    Clarke, Nick; Farthing, Jonathan P; Lanovaz, Joel L; Krentz, Joel R

    2015-05-01

    This study assessed the effects of a fatiguing game simulation (G-Sim) on the balance of collegiate Canadian football players. The purpose of the study was to evaluate postural control as a potential tool for monitoring neuromuscular fatigue (NMF) in collision-based team sports. Fifteen male Canadian football players were recruited (mean±SD: age 21.8±1.6 years, weight 97.6±14.7 kg). Indirect NMF measures (postural sway and countermovement jump (CMJ)) were performed 24 h before (TBase), immediately before (TPre) and after (TPost), and 24 h (T24) and 48 h after (T48) a Canadian football G-Sim. Peak isometric knee extensor torque of a maximal voluntary contraction (MVC) and electrically evoked tetani at 20 Hz (P20) and 80 Hz (P80) were also recorded as direct NMF measures at TBase, TPre, TPost, and T48. At TPost, we observed significant declines in MVC, P20, and the MVC/P80 ratio (-15.3%, -15.7%, and -12.1%, respectively; n=12) along with reductions in CMJ takeoff velocity and peak power (-6.9% and -6.5%, respectively; n=12) and larger area of the center of pressure trajectory (95.2%; n=10) during a 60-s postural sway task. All variables were no longer different than baseline by T48. Acute neuromuscular impairment in this cohort is likely attributable to alterations in excitation-contraction coupling due to structural damage and central activation failure. Congruency between the direct and indirect measures of NMF suggests monitoring postural sway has the potential to identify both neuromuscular and somatosensory alterations induced by acute game-induced fatigue in collision-based team sports players.

  10. The Punctum Fixum-Punctum Mobile Model: A Neuromuscular Principle for Efficient Movement Generation?

    PubMed Central

    von Laßberg, Christoph; Rapp, Walter

    2015-01-01

    According to the “punctum fixum–punctum mobile model” that was introduced in prior studies, for generation of the most effective intentional acceleration of a body part the intersegmental neuromuscular onset succession has to spread successively from the rotation axis (punctum fixum) toward the body part that shall be accelerated (punctum mobile). The aim of the present study was to investigate whether this principle is, indeed, fundamental for any kind of efficient rotational accelerations in general, independent of the kind of movements, type of rotational axis, the current body position, or movement direction. Neuromuscular onset succession was captured by surface electromyography of relevant muscles of the anterior and posterior muscle chain in 16 high-level gymnasts during intentional accelerating movement phases while performing 18 different gymnastics elements (in various body positions to forward and backward, performed on high bar, parallel bars, rings and trampoline), as well as during non-sport specific pivot movements around the longitudinal axis. The succession patterns to generate the acceleration phases during these movements were described and statistically evaluated based on the onset time difference between the muscles of the corresponding muscle chain. In all the analyzed movement phases, the results clearly support the hypothesized succession pattern from punctum fixum to punctum mobile. This principle was further underlined by the finding that the succession patterns do change their direction running through the body when the rotational axis (punctum fixum) has been changed (e.g., high bar or rings [hands] vs. floor or trampoline [feet]). The findings improve our understanding of intersegmental neuromuscular coordination patterns to generate intentional movements most efficiently. This could help to develop more specific methods to facilitate such patterns in particular contexts, thus allowing for shorter motor learning procedures of

  11. Sex alters impact of repeated bouts of sprint exercise on neuromuscular activity in trained athletes.

    PubMed

    Billaut, François; Smith, Kurt

    2009-08-01

    This study characterized the effect of sex on neuromuscular activity during repeated bouts of sprint exercise. Thirty-three healthy male and female athletes performed twenty 5-s cycle sprints separated by 25 s of rest. Mechanical work and integrated electromyograhs (iEMG) of 4 muscles of the dominant lower limb were calculated in every sprint. The iEMG signals from individual muscles were summed to represent overall electrical activity of these muscles (sum-iEMG). Neuromuscular efficiency (NME) was calculated as the ratio of mechanical work and sum-iEMG for every sprint. Arterial oxygen saturation was estimated (SpO2) with pulse oximetry throughout the protocol. The sprint-induced work decrement (18.9% vs. 29.6%; p < 0.05) and sum-iEMG reduction (11.4% vs. 19.4%; p < 0.05) were less for the women than for the men. However, the sprints decreased NME (10.1%; p < 0.05) and SpO2 (3.4%; p < 0.05) without showing sex dimorphism. Changes in SpO2 and sum-iEMG were strongly correlated in both sexes (men, R2 = 0.87; women, R2 = 0.91; all p < 0.05), although the slope of this relationship differed (6.3 +/- 2.9 vs. 3.8 +/- 1.6, respectively; p < 0.05). It is suggested that the sex difference in fatigue during repeated bouts of sprint exercise is not likely to be explained by a difference in muscle contractility impairment in men and women, but may be due to a sex difference in muscle recruitment strategy. We speculate that women would be less sensitive to arterial O2 desaturation than men, which may trigger lower neuromuscular adjustments to exhaustive exercise.

  12. Reversal of profound vecuronium-induced neuromuscular block under sevoflurane anesthesia: sugammadex versus neostigmine.

    PubMed Central

    2010-01-01

    Background Acetylcholinesterase inhibitors cannot rapidly reverse profound neuromuscular block. Sugammadex, a selective relaxant binding agent, reverses the effects of rocuronium and vecuronium by encapsulation. This study assessed the efficacy of sugammadex compared with neostigmine in reversal of profound vecuronium-induced neuromuscular block under sevoflurane anesthesia. Methods Patients aged ≥18 years, American Society of Anesthesiologists class 1-4, scheduled to undergo surgery under general anesthesia were enrolled in this phase III, multicenter, randomized, safety-assessor blinded study. Sevoflurane anesthetized patients received vecuronium 0.1 mg/kg for intubation, with maintenance doses of 0.015 mg/kg as required. Patients were randomized to receive sugammadex 4 mg/kg or neostigmine 70 μg/kg with glycopyrrolate 14 μg/kg at 1-2 post-tetanic counts. The primary efficacy variable was time from start of study drug administration to recovery of the train-of-four ratio to 0.9. Safety assessments included physical examination, laboratory data, vital signs, and adverse events. Results Eighty three patients were included in the intent-to-treat population (sugammadex, n = 47; neostigmine, n = 36). Geometric mean time to recovery of the train-of-four ratio to 0.9 was 15-fold faster with sugammadex (4.5 minutes) compared with neostigmine (66.2 minutes; p < 0.0001) (median, 3.3 minutes with sugammadex versus 49.9 minutes with neostigmine). No serious drug-related adverse events occurred in either group. Conclusions Recovery from profound vecuronium-induced block is significantly faster with sugammadex, compared with neostigmine. Neostigmine did not rapidly reverse profound neuromuscular block (Trial registration number: NCT00473694). PMID:20809967

  13. Neuromuscular and Blood Lactate Response After a Motocross Training Session in Amateur Riders

    PubMed Central

    Simões, Vinicius Radenzev; Crisp, Alex Harley; Verlengia, Rozangela; Pellegrinotti, Idico Luiz

    2016-01-01

    Background Motocross is one of the most popular motorized off-road sports, characterized by riding on irregular natural terrain of hard earth and/or sand with various obstacles throughout the course. Objectives This study evaluated the influence of a motocross training session on neuromuscular response and blood lactate in amateur riders. Patients and Methods Nine motocross riders (22.7 ± 2.8 years) participating in amateur competitions at the state level conducted a training session of 20 minutes duration at a motocross track (1.6 km) with a 250-cc four-stroke motorcycle. Metabolic demand was measured with blood lactate concentrations before and immediately, 3, 5, 8, and 10 minutes after the training session. To measure neuromuscular response, riders completed handgrip strength and horizontal jump tests before and 10 minutes after the training session. Student’s t-test and analysis of variance one-way repeated measures were used to compare the changes before and after the motocross training session. Results Significant decreases in handgrip strength were observed for both hands (left: P = 0.010 and right: P = 0.004). However, no significant difference (P = 0.241) in horizontal jump ability was observed. Significant blood lactate values were observed immediately (P = 0.001), 3 (P = 0.001), 5 (P = 0.001), and 8 (P = 0.01) minutes after training when compared to the value before training. The peak blood lactate value was 6.5 ± 2.7 mM at 8 minutes after the training session. Conclusions Amateur motocross riders had significant anaerobic metabolism demands and had reduced handgrip strength following a training session. These data suggest an importance of physical training aimed at improving anaerobic and neuromuscular performance of the upper limbs in amateur motocross riders. PMID:27625748

  14. Impaired Synaptic Development, Maintenance, and Neuromuscular Transmission in LRP4 Myasthenia

    PubMed Central

    Selcen, Duygu; Ohkawara, Bisei; Shen, Xin-Ming; McEvoy, Kathleen; Ohno, Kinji; Engel, Andrew G.

    2015-01-01

    IMPORTANCE Congenital myasthenic syndromes (CMS) are heterogeneous disorders. Defining the phenotypic features, genetic basis, and pathomechanisms of a CMS is relevant to prognosis, genetic counseling, and therapy. OBJECTIVE To characterize clinical, structural, electrophysiologic, and genetic features of a CMS and search for optimal therapy. DESIGN, SETTINGS, AND PARTICIPANTS Two sisters, 34 and 20 years of age suffering from a CMS affecting the limb-girdle muscles were investigated at an academic medical center by clinical observation, in vitro analysis of neuromuscular transmission, cytochemical and electron microscopy studies of the neuromuscular junction, exome sequencing, expression studies in HEK293 and COS-7 cells, and for response to therapy. MAIN OUTCOMES AND MEASURES We identified the disease gene and mutation, confirmed pathogenicity of the mutation by expression studies, and instituted optimal pharmacotherapy. RESULTS Intercostal muscle endplates (EPs) were abnormally small with attenuated reactivities for the acetylcholine receptor and acetylcholine esterase. Most EPs had poorly differentiated or degenerate junctional folds and some appeared denuded of nerve terminals. The amplitude of the EP potential (EPP), the miniature EPP, and the quantal content of the EPP were all markedly reduced. Exome sequencing identified a novel homozygous p.Glu1233Ala mutation in LRP4, a coreceptor for agrin to activate MuSK, required for EP development and maintenance. Expression studies indicate the mutation compromises ability of LRP4 to bind to, phosphorylate, and activate MuSK. Albuterol improved the patients’ symptoms. CONCLUSIONS AND RELEVANCE We identify a second CMS kinship harboring mutations in LRP4, identify the mechanisms that impair neuromuscular transmission, and mitigate the disease by appropriate therapy. PMID:26052878

  15. The punctum fixum-punctum mobile model: a neuromuscular principle for efficient movement generation?

    PubMed

    von Laßberg, Christoph; Rapp, Walter

    2015-01-01

    According to the "punctum fixum-punctum mobile model" that was introduced in prior studies, for generation of the most effective intentional acceleration of a body part the intersegmental neuromuscular onset succession has to spread successively from the rotation axis (punctum fixum) toward the body part that shall be accelerated (punctum mobile). The aim of the present study was to investigate whether this principle is, indeed, fundamental for any kind of efficient rotational accelerations in general, independent of the kind of movements, type of rotational axis, the current body position, or movement direction. Neuromuscular onset succession was captured by surface electromyography of relevant muscles of the anterior and posterior muscle chain in 16 high-level gymnasts during intentional accelerating movement phases while performing 18 different gymnastics elements (in various body positions to forward and backward, performed on high bar, parallel bars, rings and trampoline), as well as during non-sport specific pivot movements around the longitudinal axis. The succession patterns to generate the acceleration phases during these movements were described and statistically evaluated based on the onset time difference between the muscles of the corresponding muscle chain. In all the analyzed movement phases, the results clearly support the hypothesized succession pattern from punctum fixum to punctum mobile. This principle was further underlined by the finding that the succession patterns do change their direction running through the body when the rotational axis (punctum fixum) has been changed (e.g., high bar or rings [hands] vs. floor or trampoline [feet]). The findings improve our understanding of intersegmental neuromuscular coordination patterns to generate intentional movements most efficiently. This could help to develop more specific methods to facilitate such patterns in particular contexts, thus allowing for shorter motor learning procedures of context

  16. Effect of jumping interval training on neuromuscular and physiological parameters: a randomized controlled study.

    PubMed

    Ache-Dias, Jonathan; Dellagrana, Rodolfo A; Teixeira, Anderson S; Dal Pupo, Juliano; Moro, Antônio R P

    2016-01-01

    This study analyzed the effect of 4 weeks of jumping interval training (JIT), included in endurance training, on neuromuscular and physiological parameters. Eighteen recreational runners, randomized in control and experimental groups, performed 40 min of running at 70% of velocity at peak oxygen uptake, for 3 times per week. Additionally, the experimental group performed the JIT twice per week, which consisted of 4 to 6 bouts of continuous vertical jumps (30 s) with 5-min intervals. Three days before and after the training period, the countermovement (CMJ) and continuous jump (CJ30), isokinetic and isometric evaluation of knee extensors/flexors, progressive maximal exercise, and submaximal constant-load exercise were performed. The JIT provoked improvement in neuromuscular performance, indicated by (i) increased jump height (4.7%; effect size (ES) = 0.99) and power output (≈ 3.7%; ES ≈ 0.82) of CMJ and rate of torque development of knee extensors in isometric contraction (29.5%; ES = 1.02); (ii) anaerobic power and capacity, represented by the mean of jump height (7.4%; ES = 0.8), and peak power output (PPO) (5.6%; ES = 0.73) of the first jumps of CJ30 and the mean of jump height (10.2%, ES = 1.04) and PPO (9.5%, ES = 1.1), considering all jumps of CJ30; and (iii) aerobic power and capacity, represented by peak oxygen uptake (9.1%, ES = 1.28), velocity at peak oxygen uptake (2.7%, ES = 1.11), and velocity corresponding to the onset of blood lactate accumulation (9.7%, ES = 1.23). These results suggest that the JIT included in traditional endurance training induces moderate to large effects on neuromuscular and physiological parameters.

  17. Neuromuscular function and fatigue resistance of the plantar flexors following short-term cycling endurance training.

    PubMed

    Behrens, Martin; Weippert, Matthias; Wassermann, Franziska; Bader, Rainer; Bruhn, Sven; Mau-Moeller, Anett

    2015-01-01

    Previously published studies on the effect of short-term endurance training on neuromuscular function of the plantar flexors have shown that the H-reflex elicited at rest and during weak voluntary contractions was increased following the training regime. However, these studies did not test H-reflex modulation during isometric maximum voluntary contraction (iMVC) and did not incorporate a control group in their study design to compare the results of the endurance training group to individuals without the endurance training stimulus. Therefore, this randomized controlled study was directed to investigate the neuromuscular function of the plantar flexors at rest and during iMVC before and after 8 weeks of cycling endurance training. Twenty-two young adults were randomly assigned to an intervention group and a control group. During neuromuscular testing, rate of torque development, isometric maximum voluntary torque and muscle activation were measured. Triceps surae muscle activation and tibialis anterior muscle co-activation were assessed by normalized root mean square of the EMG signal during the initial phase of contraction (0-100, 100-200 ms) and iMVC of the plantar flexors. Furthermore, evoked spinal reflex responses of the soleus muscle (H-reflex evoked at rest and during iMVC, V-wave), peak twitch torques induced by electrical stimulation of the posterior tibial nerve at rest and fatigue resistance were evaluated. The results indicate that cycling endurance training did not lead to a significant change in any variable of interest. Data of the present study conflict with the outcome of previously published studies that have found an increase in H-reflex excitability after endurance training. However, these studies had not included a control group in their study design as was the case here. It is concluded that short-term cycling endurance training does not necessarily enhance H-reflex responses and fatigue resistance. PMID:26029114

  18. Effects of intensive physical rehabilitation on neuromuscular adaptations in adults with poststroke hemiparesis.

    PubMed

    Andersen, Lars L; Zeeman, Peter; Jørgensen, Jørgen R; Bech-Pedersen, Daniel T; Sørensen, Janne; Kjær, Michael; Andersen, Jesper L

    2011-10-01

    Hemiparesis-disability and muscle weakness of 1 side of the body-is a common consequence of stroke. High-intensity strength training may be beneficial to regain function, but strength coaches in the field of rehabilitation need evidence-based guidelines. The purpose of this study was to evaluate the effect of intensive physical rehabilitation on neuromuscular and functional adaptations in outpatients suffering from hemiparesis after stroke. A within-subject repeated-measures design with the paretic leg as the experimental leg and the nonparetic leg as the control leg was used. Eleven outpatients with hemiparesis after stroke participated in 12 weeks of intensive physical rehabilitation comprising unilateral high-intensity strength training with near-maximal loads (4-12 repetition maximum) and body weight supported treadmill training. At baseline and 12-week follow-up, the patients went through testing consisting of isokinetic muscle strength, neuromuscular activation measured with electromyography (EMG), electrically evoked muscle twitch contractile properties, and gait performance (10-m Walk Test and 6-min Walk Test). After the 12-week conditioning program, knee extensor and flexor strength increased during all contraction modes and velocities in the paretic leg. Significant increases were observed for agonist EMG amplitude at slow concentric and slow eccentric contraction. Twitch torque increased, whereas twitch time-to-peak tension remained unchanged. By contrast, no significant changes were observed in the nonparetic control leg. Gait performance increased 52-68%. In conclusion, intensive physical rehabilitation after stroke leads to clinically relevant neuromuscular improvements, leading to increased voluntary strength during a wide range of contraction modes and velocities, and improved gait velocity. Strength training coaches working in the field of rehabilitation can use this knowledge to safely and efficiently add high-intensity strength training to

  19. Short term modulation of trunk neuromuscular responses following spinal manipulation: a control group study

    PubMed Central

    2013-01-01

    Background Low back pain (LBP) is one of the most frequent musculoskeletal conditions in industrialized countries and its economic impact is important. Spinal manipulation therapy (SMT) is believed to be a valid approach in the treatment of both acute and chronic LBP. It has also been shown that SMT can modulate the electromyographic (EMG) activity of the paraspinal muscle. The purpose of this study was to investigate, in a group of patients with low back pain, the persistence of changes observed in trunk neuromuscular responses after a spinal manipulation (SMT). Methods Sixty adult participants with LBP performed a block of 5 flexion-extension movements. Participants in the experimental group (n=30) received lumbar SMT whereas participants in the control group (n=30) were positioned similarly for the treatment but did not receive SMT. Blocks of flexion-extension movements were repeated immediately after the manipulation as well as 5 and 30 minutes after SMT (or control position). EMG activity of paraspinal muscles was recorded at L2 and L5 level and kinematic data were collected to evaluate the lumbo-pelvic kinematics. Pain intensity was noted after each block. Normalized EMG, pain intensity and lumbo-pelvic kinematics were compared across experimental conditions. Results Participants from the control group showed a significant increase in EMG activity during the last block (30 min) of flexion-extension trials in both flexion and full-flexion phases at L2. Increase in VAS scores was also observed in the last 2 blocks (5 min and 30 min) in the control group. No significant group x time interaction was seen at L5. No significant difference was observed in the lumbo-pelvic kinematics. Conclusion Changes in trunk neuromuscular control following HVLA spinal manipulation may reduce sensitization or muscle fatigue effects related to repetitive movement. Future studies should investigate short term changes in neuromuscular components, tissue properties and clinical

  20. Effects of hamstring-emphasized neuromuscular training on strength and sprinting mechanics in football players.

    PubMed

    Mendiguchia, J; Martinez-Ruiz, E; Morin, J B; Samozino, P; Edouard, P; Alcaraz, P E; Esparza-Ros, F; Mendez-Villanueva, A

    2015-12-01

    The objective of this study was to examine the effects of a neuromuscular training program combining eccentric hamstring muscle strength, plyometrics, and free/resisted sprinting exercises on knee extensor/flexor muscle strength, sprinting performance, and horizontal mechanical properties of sprint running in football (soccer) players. Sixty footballers were randomly assigned to an experimental group (EG) or a control group (CG). Twenty-seven players completed the EG and 24 players the CG. Both groups performed regular football training while the EG performed also a neuromuscular training during a 7-week period. The EG showed a small increases in concentric quadriceps strength (ES = 0.38/0.58), a moderate to large increase in concentric (ES = 0.70/0.74) and eccentric (ES = 0.66/0.87) hamstring strength, and a small improvement in 5-m sprint performance (ES = 0.32). By contrast, the CG presented lower magnitude changes in quadriceps (ES = 0.04/0.29) and hamstring (ES = 0.27/0.34) concentric muscle strength and no changes in hamstring eccentric muscle strength (ES = -0.02/0.11). Thus, in contrast to the CG (ES = -0.27/0.14), the EG showed an almost certain increase in the hamstring/quadriceps strength functional ratio (ES = 0.32/0.75). Moreover, the CG showed small magnitude impairments in sprinting performance (ES = -0.35/-0.11). Horizontal mechanical properties of sprint running remained typically unchanged in both groups. These results indicate that a neuromuscular training program can induce positive hamstring strength and maintain sprinting performance, which might help in preventing hamstring strains in football players. PMID:25556888

  1. Impairment of neuromuscular propagation during human fatiguing contractions at submaximal forces.

    PubMed Central

    Fuglevand, A J; Zackowski, K M; Huey, K A; Enoka, R M

    1993-01-01

    1. The purpose of the study was to examine the dependence of neuromuscular propagation impairment on the level of isometric force sustained to the endurance limit. The task involved human volunteers sustaining a submaximal abduction force with the index finger by activating the first dorsal interosseous muscle as long as possible. 2. The submaximal force was sustained at one of three levels (20, 35 or 65% of maximum) by increasing motor unit activity, as indicated by the electromyogram (EMG), during the fatiguing contraction. Although the EMG increased during the fatiguing contraction, the EMG was significantly less than maximum at the endurance limit for all subjects (deficit of 19-55% of maximum). This deficit was inversely related to the level of the sustained submaximal force. 3. The maximum voluntary contraction and twitch forces were significantly reduced following the fatiguing contraction. As with the EMG, the degree of force reduction was greatest for the subjects who sustained the low target forces. 4. The fatiguing contraction caused a 12-23% decline in M wave amplitude, a 33-51% increase in M wave duration, and no change in M wave area. The decline in M wave amplitude, which is an index of neuromuscular propagation impairment, was greatest among the subjects who sustained the low target forces. 5. The mean power frequency of the EMG decreased by a similar amount (50-57%) during the fatiguing contraction for all three groups of subjects. 6. A model representing the interaction of processes that enhance and impair force was developed to explain the recovery of twitch force following the sustained contractions at different target forces. 7. We conclude that the fatigue experienced by a subject when force is sustained at a submaximal value does involve an impairment of neuromuscular propagation. This impairment is one factor that limits muscle excitation during a submaximal, fatiguing contraction and contributes to the diminished force capability by the end

  2. Cause of exercise associated muscle cramps (EAMC)--altered neuromuscular control, dehydration or electrolyte depletion?

    PubMed

    Schwellnus, M P

    2009-06-01

    Exercise Associated Muscle Cramps (EAMC) is one of the most common conditions that require medical attention during or immediately after sports events. Despite the high prevalence of this condition the aetiology of EAMC in athletes is still not well understood. The purpose of this review is to examine current scientific evidence in support of (1) the "electrolyte depletion" and "dehydration" hypotheses and (2) the "altered neuromuscular control" hypothesis in the aetiology of EAMC. In this review, scientific evidence will, as far as possible, be presented using evidence-based medicine criteria. This is particularly relevant in this field, as the quality of experimental methodology varies considerably among studies that are commonly cited in support of hypotheses to explain the aetiology of EAMC. Scientific evidence in support of the "electrolyte depletion" and "dehydration" hypotheses for the aetiology of EAMC comes mainly from anecdotal clinical observations, case series totalling 18 cases, and one small (n = 10) case-control study. Results from four prospective cohort studies do not support these hypotheses. In addition, the "electrolyte depletion" and "dehydration" hypotheses do not offer plausible pathophysiological mechanisms with supporting scientific evidence that could adequately explain the clinical presentation and management of EAMC. Scientific evidence for the "altered neuromuscular control" hypothesis is based on evidence from research studies in human models of muscle cramping, epidemiological studies in cramping athletes, and animal experimental data. Whilst it is clear that further evidence to support the "altered neuromuscular control" hypothesis is also required, research data are accumulating that support this as the principal pathophysiological mechanism for the aetiology of EAMC.

  3. Bone morphogenetic protein signaling in vertebrate motor neurons and neuromuscular communication

    PubMed Central

    Osses, Nelson; Henríquez, Juan P.

    2015-01-01

    An accurate communication between motor neurons and skeletal muscle fibers is required for the proper assembly, growth and maintenance of neuromuscular junctions (NMJs). Several signaling and extracellular matrix molecules play stimulatory and inhibitory roles on the assembly of functional synapses. Studies in Drosophila have revealed crucial functions for early morphogens, such as members of the Wnt and Bone Morphogenetic Proteins (BMP) signaling pathways, during the assembly and maturation of the NMJ. Here, we bring together recent findings that led us to propose that BMPs also work in vertebrate organisms as diffusible cues to communicate motor neurons and skeletal muscles. PMID:25674047

  4. Knee and Hip Joint Kinematics Predict Quadriceps and Hamstrings Neuromuscular Activation Patterns in Drop Jump Landings

    PubMed Central

    Malfait, Bart; Dingenen, Bart; Smeets, Annemie; Staes, Filip; Pataky, Todd; Robinson, Mark A.; Vanrenterghem, Jos; Verschueren, Sabine

    2016-01-01

    Purpose The purpose was to assess if variation in sagittal plane landing kinematics is associated with variation in neuromuscular activation patterns of the quadriceps-hamstrings muscle groups during drop vertical jumps (DVJ). Methods Fifty female athletes performed three DVJ. The relationship between peak knee and hip flexion angles and the amplitude of four EMG vectors was investigated with trajectory-level canonical correlation analyses over the entire time period of the landing phase. EMG vectors consisted of the {vastus medialis(VM),vastus lateralis(VL)}, {vastus medialis(VM),hamstring medialis(HM)}, {hamstring medialis(HM),hamstring lateralis(HL)} and the {vastus lateralis(VL),hamstring lateralis(HL)}. To estimate the contribution of each individual muscle, linear regressions were also conducted using one-dimensional statistical parametric mapping. Results The peak knee flexion angle was significantly positively associated with the amplitudes of the {VM,HM} and {HM,HL} during the preparatory and initial contact phase and with the {VL,HL} vector during the peak loading phase (p<0.05). Small peak knee flexion angles were significantly associated with higher HM amplitudes during the preparatory and initial contact phase (p<0.001). The amplitudes of the {VM,VL} and {VL,HL} were significantly positively associated with the peak hip flexion angle during the peak loading phase (p<0.05). Small peak hip flexion angles were significantly associated with higher VL amplitudes during the peak loading phase (p = 0.001). Higher external knee abduction and flexion moments were found in participants landing with less flexed knee and hip joints (p<0.001). Conclusion This study demonstrated clear associations between neuromuscular activation patterns and landing kinematics in the sagittal plane during specific parts of the landing. These findings have indicated that an erect landing pattern, characterized by less hip and knee flexion, was significantly associated with an

  5. Accuracy and safety of pedicle screw placement in neuromuscular scoliosis with free-hand technique

    PubMed Central

    Modi, Hitesh N.; Fernandez, Harry; Yang, Jae Hyuk; Song, Hae-Ryong

    2008-01-01

    It is a retrospective analytic study of 1,009 transpedicular screws (689 thoracic and 320 lumbosacral), inserted with free-hand technique in neuromuscular scoliosis using postoperative CT scan. The aim of paper was to determine the accuracy and safety of transpedicular screw placement with free-hand technique in neuromuscular scoliosis and to compare the accuracy at different levels in such population. All studies regarding accuracy and safety of pedicle screw in scoliosis represent idiopathic scoliosis using various techniques such as free-hand, navigation, image intensifier, etc., for screw insertion. Anatomies of vertebrae and pedicle are distorted in scoliosis, hence accurate and safe placement of pedicle screw is prerequisite for surgery. Between 2004 and 2006, 37 consecutive patients, average age 20 years (9–44 years), of neuromuscular scoliosis were operated with posterior pedicle screw fixation using free-hand technique. Accuracy of pedicle screws was studied on postoperative CT scan. Placement up to 2 mm medial side and 4 mm lateral side was considered within-safe zone. Of the 1,009 screws, 273 screws were displaced medially, laterally or on the anterior side showing that 73% screws (68% in thoracic and 82.5% in lumbar spine) were accurately placed within pedicle. Considering the safe zone, 93.3% (942/1009, 92.4% in thoracic and 95.3% in lumbar spine) of the screws were within the safe zone. Comparing accuracy according to severity of curve, accuracy was 75% in group 1 (curve <90°) and 69% in group 2 (curve >90°) with a safety of 94.8 and 91.2%, respectively (P = 0.35). Comparing the accuracy at different thoracic levels, it showed 67, 64 and 72% accuracy in upper, middle and lower thoracic levels with safety of 96.6, 89.2 and 93.1%, respectively, exhibiting no statistical significant difference (P = 0.17). Pedicle screw placement in neuromuscular scoliosis with free-hand technique is accurate and safe as other conditions. PMID:18830636

  6. [Anesthetic Management of a Patient with Facioscapulohumeral Muscular Dystrophy: Importance of Monitoring Neuromuscular Function at Multiple Sites].

    PubMed

    Matsui, Shuhei; Tanaka, Satoshi; Kiyosawa, Kenkichi; Tanaka, Toshiyuki; Kawamata, Mikito

    2015-12-01

    A 39-year-old female with facioscapulohumeral muscular dystrophy (FSHD) was scheduled for thoracoscopic resection of an anterior mediastinal tumor. She had slowly progressive weakness and atrophy in the fascial and shoulder girdle muscles. General anesthesia was induced and maintained with propofol, remifentanil, and fentanyl combined with thoracic paravertebral block. Rocuronium-induced neuromuscular blockade was evaluated with acceleromyography at the corrugator supercilii, masseter, and adductor pollicis muscles. There was no reaction at the atrophic corrugator supercilii muscle in response to train-of-four (TOF) stimulation even before rocuronium administration. In contrast twitch responses at the masseter and adductor pollicis muscles to TOF stimulation could be evoked and the duration of action of rocuronium was found to be similar to that of the normal population. The perioperative course was uneventful. Neuromuscular monitoring sites should be carefully selected in FSHD patients because of possible inability to monitor neuromuscular function at the atrophic muscles. PMID:26790332

  7. Neuromuscular orthotics in the treatment of craniomandibular dysfunction and the effects on patients with multiple sclerosis: a pilot study.

    PubMed

    Heit, Tammarie

    2011-01-01

    The purpose of this pilot study was to identify, measure and document an effect on the subjective multiple sclerosis symptoms and compare it to any objective data changes in the neuromuscular system of the head and neck, following the correction of the jaw position using a neuromuscular orthotic. The hope is to provide clinical evidence of improvement in the disease long-term without relying on the subjective evidence of remissions and exacerbations reported by the patient. The evidence found in the current pilot study measured improvement of head position, jaw position, jaw function, and airway in the neuromuscular bite position, which correlated with the improvement of subjective symptoms of craniomandibular dysfunction and multiple sclerosis. Studies show that the bite affects blood flow in the brain, which may explain the improvement of the patients in the current study. PMID:21370770

  8. A Markov computer simulation model of the economics of neuromuscular blockade in patients with acute respiratory distress syndrome

    PubMed Central

    Macario, Alex; Chow, John L; Dexter, Franklin

    2006-01-01

    Background Management of acute respiratory distress syndrome (ARDS) in the intensive care unit (ICU) is clinically challenging and costly. Neuromuscular blocking agents may facilitate mechanical ventilation and improve oxygenation, but may result in prolonged recovery of neuromuscular function and acute quadriplegic myopathy syndrome (AQMS). The goal of this study was to address a hypothetical question via computer modeling: Would a reduction in intubation time of 6 hours and/or a reduction in the incidence of AQMS from 25% to 21%, provide enough benefit to justify a drug with an additional expenditure of $267 (the difference in acquisition cost between a generic and brand name neuromuscular blocker)? Methods The base case was a 55 year-old man in the ICU with ARDS who receives neuromuscular blockade for 3.5 days. A Markov model was designed with hypothetical patients in 1 of 6 mutually exclusive health states: ICU-intubated, ICU-extubated, hospital ward, long-term care, home, or death, over a period of 6 months. The net monetary benefit was computed. Results Our computer simulation modeling predicted the mean cost for ARDS patients receiving standard care for 6 months to be $62,238 (5% – 95% percentiles $42,259 – $83,766), with an overall 6-month mortality of 39%. Assuming a ceiling ratio of $35,000, even if a drug (that cost $267 more) hypothetically reduced AQMS from 25% to 21% and decreased intubation time by 6 hours, the net monetary benefit would only equal $137. Conclusion ARDS patients receiving a neuromuscular blocker have a high mortality, and unpredictable outcome, which results in large variability in costs per case. If a patient dies, there is no benefit to any drug that reduces ventilation time or AQMS incidence. A prospective, randomized pharmacoeconomic study of neuromuscular blockers in the ICU to asses AQMS or intubation times is impractical because of the highly variable clinical course of patients with ARDS. PMID:16539706

  9. Neuromuscular electrical stimulation and dietary interventions to reduce oxidative stress in a secondary progressive multiple sclerosis patient leads to marked gains in function: a case report.

    PubMed

    Reese, David; Shivapour, Ezzatolah T; Wahls, Terry L; Dudley-Javoroski, Shauna D; Shields, Richard

    2009-01-01

    Neuromuscular electrical stimulation has been used to aid musculoskeletal recovery. Excessive oxidative stress and excitoxicity are implicated in secondary progressive multiple sclerosis. A 52-year-old white female with SPMS had been scooter- and cane-dependent for 4 years. She requested and received a trial of neuromuscular electrical stimulation. Two months after initiating NMES the patient adopted several nutritional interventions to lower oxidative stress and excito-toxicity. During the first 2 months of neuromuscular electrical stimulation, the therapist observed modest gait improvements. Following the addition of nutritional interventions, more rapids gains in strength and endurance, including muscle groups not receiving neuromuscular electrical stimulation were observed by both the therapist and the patient. After 8 months of neuromuscular electrical stimulation (6 months of nutritional intervention) the patient's function had improved sufficiently that she no longer used a scooter or cane and rode her bicycle routinely 8 miles, including hills. PMID:19918474

  10. Neuromuscular electrical stimulation and dietary interventions to reduce oxidative stress in a secondary progressive multiple sclerosis patient leads to marked gains in function: a case report

    PubMed Central

    Reese, David; Shivapour, Ezzatolah T; Dudley-Javoroski, Shauna D; Shields, Richard

    2009-01-01

    Neuromuscular electrical stimulation has been used to aid musculoskeletal recovery. Excessive oxidative stress and excitoxicity are implicated in secondary progressive multiple sclerosis. A 52-year-old white female with SPMS had been scooter- and cane-dependent for 4 years. She requested and received a trial of neuromuscular electrical stimulation. Two months after initiating NMES the patient adopted several nutritional interventions to lower oxidative stress and excito-toxicity. During the first 2 months of neuromuscular electrical stimulation, the therapist observed modest gait improvements. Following the addition of nutritional interventions, more rapids gains in strength and endurance, including muscle groups not receiving neuromuscular electrical stimulation were observed by both the therapist and the patient. After 8 months of neuromuscular electrical stimulation (6 months of nutritional intervention) the patient’s function had improved sufficiently that she no longer used a scooter or cane and rode her bicycle routinely 8 miles, including hills. PMID:19918474

  11. The inhibitory effect of Camellia sinensis extracts against the neuromuscular blockade of Crotalus durissus terrificus venom

    PubMed Central

    de Jesus Reis Rosa, Luana; Silva, Gleidy Ana Araujo; Filho, Jorge Amaral; Silva, Magali Glauzer; Groppo, Francisco Carlos; Oshima-Franco, Yoko

    2010-01-01

    In geographically isolated populations where intensive medical care or serum therapy is not easily accessible snake envenomation is a major cause for concern. The aim of the present study was to test Camellia sinensis extracts, theaflavin and epigallocatechin (two of the main C. sinensis components) against the irreversible neuromuscular blockade induced by Crotalus durissus terrificus venom in mouse phrenic-nerve diaphragm preparations. A quantitative histological study was also performed. The venom (20µg/ml) completely decreased twitch tension after 70min and 5µg/ml venom abolished 50% of twitch amplitude after 60min. C. sinensis extract induced intense facilitatory effect in the preparation activity at 0.2mg/ml and slightly facilitatory effect at 0.05mg/ml. Both 0.05mg/ml C. sinensis extract and 0.05mg/ml commercial theaflavin maintained partial muscular activity in presence of 5µg/ml venom. The histological data confirms that Cs is able to protect the muscle from the myotoxic activity of the venom. Commercial epigallocatechin gallate did not show pre-synaptic nor post-synaptic activities. C. sinensis extract was able to protect the mouse phrenic-nerve diaphragm against the irreversible neuromuscular blockade induced by C. durissus terrificus venom. PMID:21544176

  12. Severe neuromuscular denervation of clinically relevant muscles in a mouse model of spinal muscular atrophy.

    PubMed

    Ling, Karen K Y; Gibbs, Rebecca M; Feng, Zhihua; Ko, Chien-Ping

    2012-01-01

    Spinal muscular atrophy (SMA), a motoneuron disease caused by a deficiency of the survival of motor neuron (SMN) protein, is characterized by motoneuron loss and muscle weakness. It remains unclear whether widespread loss of neuromuscular junctions (NMJs) is involved in SMA pathogenesis. We undertook a systematic examination of NMJ innervation patterns in >20 muscles in the SMNΔ7 SMA mouse model. We found that severe denervation (<50% fully innervated endplates) occurs selectively in many vulnerable axial muscles and several appendicular muscles at the disease end stage. Since these vulnerable muscles were located throughout the body and were comprised of varying muscle fiber types, it is unlikely that muscle location or fiber type determines susceptibility to denervation. Furthermore, we found a similar extent of neurofilament accumulation at NMJs in both vulnerable and resistant muscles before the onset of denervation, suggesting that neurofilament accumulation does not predict subsequent NMJ denervation. Since vulnerable muscles were initially innervated, but later denervated, loss of innervation in SMA may be attributed to defects in synapse maintenance. Finally, we found that denervation was amendable by trichostatin A (TSA) treatment, which increased innervation in clinically relevant muscles in TSA-treated SMNΔ7 mice. Our findings suggest that neuromuscular denervation in vulnerable muscles is a widespread pathology in SMA, and can serve as a preparation for elucidating the biological basis of synapse loss, and for evaluating therapeutic efficacy.

  13. Distinct neural and neuromuscular strategies underlie independent evolution of simplified advertisement calls.

    PubMed

    Leininger, Elizabeth C; Kelley, Darcy B

    2013-04-01

    Independent or convergent evolution can underlie phenotypic similarity of derived behavioural characters. Determining the underlying neural and neuromuscular mechanisms sheds light on how these characters arose. One example of evolutionarily derived characters is a temporally simple advertisement call of male African clawed frogs (Xenopus) that arose at least twice independently from a more complex ancestral pattern. How did simplification occur in the vocal circuit? To distinguish shared from divergent mechanisms, we examined activity from the calling brain and vocal organ (larynx) in two species that independently evolved simplified calls. We find that each species uses distinct neural and neuromuscular strategies to produce the simplified calls. Isolated Xenopus borealis brains produce fictive vocal patterns that match temporal patterns of actual male calls; the larynx converts nerve activity faithfully into muscle contractions and single clicks. In contrast, fictive patterns from isolated Xenopus boumbaensis brains are short bursts of nerve activity; the isolated larynx requires stimulus bursts to produce a single click of sound. Thus, unlike X. borealis, the output of the X. boumbaensis hindbrain vocal pattern generator is an ancestral burst-type pattern, transformed by the larynx into single clicks. Temporally simple advertisement calls in genetically distant species of Xenopus have thus arisen independently via reconfigurations of central and peripheral vocal neuroeffectors. PMID:23407829

  14. Distinct neural and neuromuscular strategies underlie independent evolution of simplified advertisement calls

    PubMed Central

    Leininger, Elizabeth C.; Kelley, Darcy B.

    2013-01-01

    Independent or convergent evolution can underlie phenotypic similarity of derived behavioural characters. Determining the underlying neural and neuromuscular mechanisms sheds light on how these characters arose. One example of evolutionarily derived characters is a temporally simple advertisement call of male African clawed frogs (Xenopus) that arose at least twice independently from a more complex ancestral pattern. How did simplification occur in the vocal circuit? To distinguish shared from divergent mechanisms, we examined activity from the calling brain and vocal organ (larynx) in two species that independently evolved simplified calls. We find that each species uses distinct neural and neuromuscular strategies to produce the simplified calls. Isolated  Xenopus borealis brains produce fictive vocal patterns that match temporal patterns of actual male calls; the larynx converts nerve activity faithfully into muscle contractions and single clicks. In contrast, fictive patterns from isolated Xenopus boumbaensis brains are short bursts of nerve activity; the isolated larynx requires stimulus bursts to produce a single click of sound. Thus, unlike X. borealis, the output of the X. boumbaensis hindbrain vocal pattern generator is an ancestral burst-type pattern, transformed by the larynx into single clicks. Temporally simple advertisement calls in genetically distant species of Xenopus have thus arisen independently via reconfigurations of central and peripheral vocal neuroeffectors. PMID:23407829

  15. Plantar flexor neuromuscular adjustments following match-play football in hot and cool conditions.

    PubMed

    Girard, O; Nybo, L; Mohr, M; Racinais, S

    2015-06-01

    We assessed neuromuscular fatigue and recovery of the plantar flexors after playing football with or without severe heat stress. Neuromuscular characteristics of the plantar flexors were assessed in 17 male players at baseline and ∼30 min, 24, and 48 h after two 90-min football matches in temperate (∼20 °C and 55% rH) and hot (∼43 °C and 20% rH) environments. Measurements included maximal voluntary strength, muscle activation, twitch contractile properties, and rate of torque development and soleus EMG (i.e., root mean square activity) rise from 0 to 30, -50, -100, and -200 ms during maximal isometric contractions for plantar flexors. Voluntary activation and peak twitch torque were equally reduced (-1.5% and -16.5%, respectively; P < 0.05) post-matches relative to baseline in both conditions, the latter persisting for at least 48 h, whereas strength losses (∼5%) were not significant. Absolute explosive force production declined (P < 0.05) 30 ms after contraction onset independently of condition, with no change at any other epochs. Globally, normalized rate of force development and soleus EMG activity rise values remained unchanged. In football, match-induced alterations in maximal and rapid torque production capacities of the plantar flexors are moderate and do not differ after competing in temperate and hot environments.

  16. Assessing Tetraplegic Patients’ Neuro-Muscular Adaptations to a Six-Week Physiotherapeutic Programme

    PubMed Central

    Oke, Kayode Israel; Kubeyinje, Oluwaseun S.; Agwubike, Elias O.

    2012-01-01

    Spinal cord injury is a life-transforming condition of sudden onset that can have devastating consequences. A multidisciplinary, functional goal-oriented programme is required to enable the tetraplegic patient live as fully and independently life as possible. Physiotherapy is a very important part of the multidisciplinary team required to prevent many of the immobilization complications that may result in serious functional limitations, reduce overall morbidity and achieve well patterned recovery. This study therefore highlights the neuromuscular adaptations of tetraplegic patients to physiotherapy over a period of six weeks. Fifteen patients participated in this study and the results showed that even though changes in the musculoskeletal parameters are inevitable in tetraplegics, the extent/degree of reduction of these parameters was grossly minimized in the studied subjects through the administration of physiotherapeutic measures. However, further research using a large sample size will be required to evaluate the physiologic adaptations of the neuromuscular system to the physiotherapy interventions among patients with spinal cord injury. PMID:22980375

  17. Neuromuscular strategies for the transitions between level and hill surfaces during walking

    PubMed Central

    Gottschall, Jinger S.; Nichols, T. Richard

    2011-01-01

    Despite continual fluctuations in walking surface properties, humans and animals smoothly transition between terrains in their natural surroundings. Walking transitions have the potential to influence dynamic balance in both the anterior–posterior and medial–lateral directions, thereby increasing fall risk and decreasing mobility. The goal of the current manuscript is to provide a review of the literature that pertains to the topic of surface slope transitions between level and hill surfaces, as well as report the recent findings of two experiments that focus on the neuromuscular strategies of surface slope transitions. Our results indicate that in anticipation of a change in surface slope, neuromuscular patterns during level walking prior to a hill are significantly different from the patterns during level walking without the future change in surface. Typically, the changes in muscle activity were due to co-contraction of opposing muscle groups and these changes correspond to modifications in head pitch. In addition, further experiments revealed that the neck proprioceptors may be an initial source of feedback for upcoming surface slope transitions. Together, these results illustrate that in order to safely traverse varying surfaces, transitions strides are functionally distinct from either level walking or hill walking independently. PMID:21502127

  18. Excess of neuromuscular spindles in a fetus with Costello syndrome: a clinicopathological report.

    PubMed

    Sinico, Martine; Bassez, Guillaume; Touboul, Claudine; Cavé, Helene; Vergnaud, Armand; Zirah, Clément; Fleury-Feith, Jocelyne; Gettler, Sylvain; Vojtek, Anne Marie; Chevalier, Nicole; Amram, Daniel; Alsamad, Issam Abd; Haddad, Bassam; Encha-Razavi, Ferechté

    2011-01-01

    The neuromuscular spindle (NMS) is a proprioceptive myofibrillar component of skeletal muscles that is necessary to maintain normal muscle tone and coordination. Recently, an excess of NMS has been reported as a congenital neuromuscular syndrome with a Noonan phenotype, now linked to Costello syndrome (CS). The vast majority of patients with CS have a de novo heterozygous mutation in the HRAS gene involved in the Ras/mitogen-activated protein kinase (MAPK) pathway. CS has many features in common with Noonan and cardiofaciocutaneous syndromes, also linked to activating mutations (but in other genes) of the Ras/MAPK pathway. This makes the orientation of molecular screening difficult. The observation of excess NMS in a 26-weeks'-gestation stillborn prompted us to screen the HRAS gene for mutation. The identification of a HRAS mutation made it possible to establish a diagnosis of CS. We conclude that the excess of NMS is the most reliable sign for the diagnosis of CS. Our findings also show the instrumental role of histological study of the skeletal muscles in the context of polyhydramnios and fetal hydrops.

  19. Snake and Spider Toxins Induce a Rapid Recovery of Function of Botulinum Neurotoxin Paralysed Neuromuscular Junction

    PubMed Central

    Duregotti, Elisa; Zanetti, Giulia; Scorzeto, Michele; Megighian, Aram; Montecucco, Cesare; Pirazzini, Marco; Rigoni, Michela

    2015-01-01

    Botulinum neurotoxins (BoNTs) and some animal neurotoxins (β-Bungarotoxin, β-Btx, from elapid snakes and α-Latrotoxin, α-Ltx, from black widow spiders) are pre-synaptic neurotoxins that paralyse motor axon terminals with similar clinical outcomes in patients. However, their mechanism of action is different, leading to a largely-different duration of neuromuscular junction (NMJ) blockade. BoNTs induce a long-lasting paralysis without nerve terminal degeneration acting via proteolytic cleavage of SNARE proteins, whereas animal neurotoxins cause an acute and complete degeneration of motor axon terminals, followed by a rapid recovery. In this study, the injection of animal neurotoxins in mice muscles previously paralyzed by BoNT/A or /B accelerates the recovery of neurotransmission, as assessed by electrophysiology and morphological analysis. This result provides a proof of principle that, by causing the complete degeneration, reabsorption, and regeneration of a paralysed nerve terminal, one could favour the recovery of function of a biochemically- or genetically-altered motor axon terminal. These observations might be relevant to dying-back neuropathies, where pathological changes first occur at the neuromuscular junction and then progress proximally toward the cell body. PMID:26670253

  20. Effect of vibration training on neuromuscular output with ballistic knee extensions.

    PubMed

    Luo, Jin; McNamara, Brian; Moran, Kieran

    2008-10-01

    The aim of the study was to determine whether vibration applied directly to a muscle-tendon could enhance neuromuscular output during and 1.5 and 10 min after a bout of ballistic resistance training. Fourteen participants were exposed to two training conditions in random order: exercise with vibration and exercise with sham vibration. The exercise comprised three sets of ballistic knee extensions with a load of 60-70% of one-repetition maximum. Vibration (1.2 mm amplitude, 65 Hz frequency) was applied with a portable vibrator strapped over the distal tendon of the quadriceps. Knee joint angular velocity, moment, and power, and rectus femoris and vastus lateralis electromyography root-mean-squared were measured during knee extension. During and after training, the vibration did not induce significant changes in peak angular velocity, time to peak angular velocity, peak moment, time to peak moment, peak power, time to peak power, or average EMG of the rectus femoris and vastus lateralis. We conclude that direct vibration, at the selected amplitude and frequency, does not enhance these neuromuscular variables in ballistic knee extensions during or immediately after training.

  1. Chronic respiratory failure in patients with neuromuscular diseases: diagnosis and treatment.

    PubMed

    Paschoal, Ilma Aparecida; Villalba, Wander de Oliveira; Pereira, Mônica Corso

    2007-01-01

    Neuromuscular diseases affect alveolar air exchange and therefore cause chronic respiratory failure. The onset of respiratory failure can be acute, as in traumas, or progressive (slow or rapid), as in amyotrophic lateral sclerosis, muscular dystrophies, diseases of the myoneural junction, etc. Respiratory muscle impairment also affects cough efficiency and, according to the current knowledge regarding the type of treatment available in Brazil to these patients, it can be said that the high rates of morbidity and mortality in these individuals are more often related to the fact that they cough inefficiently rather than to the fact that they ventilate poorly. In this review, with the objective of presenting the options of devices available to support and substitute for natural ventilation in patients with neuromuscular diseases, we have compiled a brief history of the evolution of orthopedic braces and prostheses used to aid respiration since the end of the 19th century. In addition, we highlight the elements that are fundamental to the diagnosis of alveolar hypoventilation and of failure of the protective cough mechanism: taking of a clinical history; determination of peak cough flow; measurement of maximal inspiratory and expiratory pressures; spirometry in two positions (sitting and supine); pulse oximetry; capnography; and polysomnography. Furthermore, the threshold values available in the literature for the use of nocturnal ventilatory support and for the extension of this support through the daytime period are presented. Moreover, the maneuvers used to increase cough efficiency, as well as the proper timing of their introduction, are discussed.

  2. Acid-sensing ion channels 1a (ASIC1a) inhibit neuromuscular transmission in female mice.

    PubMed

    Urbano, Francisco J; Lino, Noelia G; González-Inchauspe, Carlota M F; González, Laura E; Colettis, Natalia; Vattino, Lucas G; Wunsch, Amanda M; Wemmie, John A; Uchitel, Osvaldo D

    2014-02-15

    Acid-sensing ion channels (ASIC) open in response to extracellular acidosis. ASIC1a, a particular subtype of these channels, has been described to have a postsynaptic distribution in the brain, being involved not only in ischemia and epilepsy, but also in fear and psychiatric pathologies. High-frequency stimulation of skeletal motor nerve terminals (MNTs) can induce presynaptic pH changes in combination with an acidification of the synaptic cleft, known to contribute to muscle fatigue. Here, we studied the role of ASIC1a channels on neuromuscular transmission. We combined a behavioral wire hanging test with electrophysiology, pharmacological, and immunofluorescence techniques to compare wild-type and ASIC1a lacking mice (ASIC1a (-/-) knockout). Our results showed that 1) ASIC1a (-/-) female mice were weaker than wild type, presenting shorter times during the wire hanging test; 2) spontaneous neurotransmitter release was reduced by ASIC1a activation, suggesting a presynaptic location of these channels at individual MNTs; 3) ASIC1a-mediated effects were emulated by extracellular local application of acid saline solutions (pH = 6.0; HEPES/MES-based solution); and 4) immunofluorescence techniques revealed the presence of ASIC1a antigens on MNTs. These results suggest that ASIC1a channels might be involved in controlling neuromuscular transmission, muscle contraction and fatigue in female mice.

  3. Acid-sensing ion channels 1a (ASIC1a) inhibit neuromuscular transmission in female mice

    PubMed Central

    Lino, Noelia G.; González-Inchauspe, Carlota M. F.; González, Laura E.; Colettis, Natalia; Vattino, Lucas G.; Wunsch, Amanda M.; Wemmie, John A.; Uchitel, Osvaldo D.

    2013-01-01

    Acid-sensing ion channels (ASIC) open in response to extracellular acidosis. ASIC1a, a particular subtype of these channels, has been described to have a postsynaptic distribution in the brain, being involved not only in ischemia and epilepsy, but also in fear and psychiatric pathologies. High-frequency stimulation of skeletal motor nerve terminals (MNTs) can induce presynaptic pH changes in combination with an acidification of the synaptic cleft, known to contribute to muscle fatigue. Here, we studied the role of ASIC1a channels on neuromuscular transmission. We combined a behavioral wire hanging test with electrophysiology, pharmacological, and immunofluorescence techniques to compare wild-type and ASIC1a lacking mice (ASIC1a −/− knockout). Our results showed that 1) ASIC1a −/− female mice were weaker than wild type, presenting shorter times during the wire hanging test; 2) spontaneous neurotransmitter release was reduced by ASIC1a activation, suggesting a presynaptic location of these channels at individual MNTs; 3) ASIC1a-mediated effects were emulated by extracellular local application of acid saline solutions (pH = 6.0; HEPES/MES-based solution); and 4) immunofluorescence techniques revealed the presence of ASIC1a antigens on MNTs. These results suggest that ASIC1a channels might be involved in controlling neuromuscular transmission, muscle contraction and fatigue in female mice. PMID:24336653

  4. Isometric quadriceps strength determines sailing performance and neuromuscular fatigue during an upwind sailing emulation.

    PubMed

    Bourgois, Jan G; Callewaert, Margot; Celie, Bert; De Clercq, Dirk; Boone, Jan

    2016-01-01

    This study investigates the physiological responses to upwind sailing on a laser emulation ergometer and analyses the components of the physical profile that determine the physiological responses related to sailing level. Ten male high-level laser sailors performed an upwind sailing test, incremental cycling test and quadriceps strength test. During the upwind sailing test, heart rate (HR), oxygen uptake, ventilation, respiratory exchange ratio, rating of perceived exertion (RPE) and lactate concentration were measured, combined with near-infrared spectroscopy (NIRS) and electromyography (EMG) registration of the M. Vastus lateralis. Repeated measures ANOVA showed for the cardio-respiratory, metabolic and muscles responses (mean power frequency [MPF], root mean square [RMS], deoxy[Hb+Mb]) during the upwind sailing test an initial significant increase followed by a stabilisation, despite a constant increase in RPE. Stepwise regression analysis showed that better sailing level was for 46.5% predicted by lower MPF decrease. Lower MPF decrease was for 57.8% predicted by a higher maximal isometric quadriceps strength. In conclusion, this study indicates that higher sailing level was mainly determined by a lower rate of neuromuscular fatigue during the upwind sailing test (as indicated by MPF decrease). Additionally, the level of neuromuscular fatigue was mainly determined by higher maximal isometric quadriceps strength stressing the importance of resistance training in the planning of training.

  5. Isometric quadriceps strength determines sailing performance and neuromuscular fatigue during an upwind sailing emulation.

    PubMed

    Bourgois, Jan G; Callewaert, Margot; Celie, Bert; De Clercq, Dirk; Boone, Jan

    2016-01-01

    This study investigates the physiological responses to upwind sailing on a laser emulation ergometer and analyses the components of the physical profile that determine the physiological responses related to sailing level. Ten male high-level laser sailors performed an upwind sailing test, incremental cycling test and quadriceps strength test. During the upwind sailing test, heart rate (HR), oxygen uptake, ventilation, respiratory exchange ratio, rating of perceived exertion (RPE) and lactate concentration were measured, combined with near-infrared spectroscopy (NIRS) and electromyography (EMG) registration of the M. Vastus lateralis. Repeated measures ANOVA showed for the cardio-respiratory, metabolic and muscles responses (mean power frequency [MPF], root mean square [RMS], deoxy[Hb+Mb]) during the upwind sailing test an initial significant increase followed by a stabilisation, despite a constant increase in RPE. Stepwise regression analysis showed that better sailing level was for 46.5% predicted by lower MPF decrease. Lower MPF decrease was for 57.8% predicted by a higher maximal isometric quadriceps strength. In conclusion, this study indicates that higher sailing level was mainly determined by a lower rate of neuromuscular fatigue during the upwind sailing test (as indicated by MPF decrease). Additionally, the level of neuromuscular fatigue was mainly determined by higher maximal isometric quadriceps strength stressing the importance of resistance training in the planning of training. PMID:26323461

  6. Differential effects of diltiazem on glutamate potentials and excitatory junctional potentials at the crayfish neuromuscular junction.

    PubMed Central

    Ishida, M; Shinozaki, H

    1980-01-01

    1. The effects of diltiazem on glutamate potentials and excitatory junctional potentials (e.j.p.s) were investigated in the crayfish neuromuscular junction. 2. When diltiazem (0.3 mM) was added to the perfusion fluid, the ionophoretic glutamate potential was reduced to about half, whereas the peak amplitude of successive e.j.p.s elicited by a train of pulses of 100/sec increased by about 2 times. 3. It was suggested that diltiazem was a non-competitive inhibitor of L-glutamate. The reduction of the response to applied glutamate was not due to the acceleration of desensitization of the glutamate receptor. The rate of recovery from desensitization was delayzed by diltiazem. 4. The increase in amplitude of e.j.p.s caused by diltiazem was due to the increase in membrane resistance. The quantum content and size of extracellular e.j.p.s were not affected by diltiazem. 5. It was substantiated using the micro-electrode technique that the glutamate sensitive area coincided with the neuromuscular junctional area. 6. The pharmacological difference between glutamate potentials and e.j.p.s revealed in the present study is difficult to explain on the glutamate transmitter hypothesis. One explanation worthy to be considered is that there are two pharmacologically different kinds of receptors sensitive to L-glutamate. PMID:7359406

  7. Respiratory motor training and neuromuscular plasticity in patients with chronic obstructive pulmonary disease: A pilot study.

    PubMed

    Ovechkin, Alexander V; Sayenko, Dimitry G; Ovechkina, Elena N; Aslan, Sevda C; Pitts, Teresa; Folz, Rodney J

    2016-07-15

    The objective of this study was to examine the feasibility of a full-scale investigation of the neurophysiological mechanisms of COPD-induced respiratory neuromuscular control deficits. Characterization of respiratory single- and multi-muscle activation patterns using surface electromyography (sEMG) were assessed along with functional measures at baseline and following 21±2 (mean±SD) sessions of respiratory motor training (RMT) performed during a one-month period in four patients with GOLD stage II or III COPD. Pre-training, the individuals with COPD showed significantly increased (p<0.05) overall respiratory muscle activity and disorganized multi-muscle activation patterns in association with lowered spirometrical measures and decreased fast- and slow-twitch fiber activity as compared to healthy controls (N=4). Following RMT, functional and respiratory sEMG activation outcomes during quite breathing and forced expiratory efforts were improved suggesting that functional improvements, induced by task-specific RMT, are evidence respiratory neuromuscular networks re-organization.

  8. Why Quantification Matters: Characterization of Phenotypes at the Drosophila Larval Neuromuscular Junction.

    PubMed

    Sanhueza, Mario; Kubasik-Thayil, Anisha; Pennetta, Giuseppa

    2016-01-01

    Most studies on morphogenesis rely on qualitative descriptions of how anatomical traits are affected by the disruption of specific genes and genetic pathways. Quantitative descriptions are rarely performed, although genetic manipulations produce a range of phenotypic effects and variations are observed even among individuals within control groups. Emerging evidence shows that morphology, size and location of organelles play a previously underappreciated, yet fundamental role in cell function and survival. Here we provide step-by-step instructions for performing quantitative analyses of phenotypes at the Drosophila larval neuromuscular junction (NMJ). We use several reliable immuno-histochemical markers combined with bio-imaging techniques and morphometric analyses to examine the effects of genetic mutations on specific cellular processes. In particular, we focus on the quantitative analysis of phenotypes affecting morphology, size and position of nuclei within the striated muscles of Drosophila larvae. The Drosophila larval NMJ is a valuable experimental model to investigate the molecular mechanisms underlying the structure and the function of the neuromuscular system, both in health and disease. However, the methodologies we describe here can be extended to other systems as well. PMID:27213489

  9. Pre- and postsynaptic changes in the neuromuscular junction in dystrophic mice

    PubMed Central

    Pratt, Stephen J. P.; Valencia, Ana P.; Le, Gloribel K.; Shah, Sameer B.; Lovering, Richard M.

    2015-01-01

    Duchenne muscular dystrophy (DMD) is a devastating neuromuscular disease in which weakness, increased susceptibility to muscle injury, and inadequate repair appear to underlie the pathology. While most attention has focused within the muscle fiber, we recently demonstrated in mdx mice (murine model for DMD) significant morphologic alterations at the motor endplate of the neuromuscular junction (NMJ) and corresponding NMJ transmission failure after injury. Here we extend these initial observations at the motor endplate to gain insight into the pre- vs. postsynaptic morphology, as well as the subsynaptic nuclei in healthy (WT) vs. mdx mice. We quantified the discontinuity and branching of the terminal nerve in adult mice. We report mdx- and age-dependent changes for discontinuity and an increase in branching when compared to WT. To examine mdx- and age-dependent changes in the relative localization of pre- and postsynaptic structures, we calculated NMJ occupancy, defined as the ratio of the footprint occupied by presynaptic vesicles vs. that of the underlying motor endplate. The normally congruent coupling between presynaptic and postsynaptic morphology was altered in mdx mice, independent of age. Finally we found an almost two-fold increase in the number of nuclei and an increase in density (nuclei/area) underlying the NMJ. These outcomes suggest substantial remodeling of the NMJ during dystrophic progression. This remodeling reflects plasticity in both pre- and postsynaptic contributors to NMJ structure, and thus perhaps also NM transmission and muscle function. PMID:26441672

  10. Neuromuscular characteristics and fatigue in endurance and sprint athletes during a new anaerobic power test.

    PubMed

    Paavolainen, L; Häkkinen, K; Nummela, A; Rusko, H

    1994-01-01

    The purpose of this study was to investigate neuromuscular and energy performance characteristics of anaerobic power and capacity and the development of fatigue. Ten endurance and ten sprint athletes performed a new maximal anaerobic running power test (MARP), which consisted of n x 20-s runs on a treadmill with 100-s recovery between the runs. Blood lactate concentration [la-]b was measured after each run to determine submaximal and maximal indices of anaerobic power (P3 mmol.l-1, P5 mmol.l-1, P10 mmol.l-1 and Pmax) which was expressed as the oxygen demand of the runs according to the American College of Sports Medicine equation: the oxygen uptake (ml.kg-1.min-1) = 0.2 x velocity (m.min-1) + 0.9 x slope of treadmill (frac) x velocity (m.min-1) + 3.5. The height of rise of the centre of gravity of the counter movement jumps before (CMJrest) and during (CMJ) the MARP test, as well as the time of force production (tF) and electromyographic (EMG) activity of the leg muscles of CMJ performed after each run were used to describe the neuromuscular performance characteristics. The maximal oxygen uptake (VO2max), anaerobic and aerobic thresholds were determined in the VO2max test, which consisted of n x 3-min runs on the treadmill.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Estimating neuromuscular stimulation within the human torso with Taser® stimulus

    NASA Astrophysics Data System (ADS)

    Sun, Hongyu; Webster, John G.

    2007-11-01

    Designers of electromuscular incapacitation devices need to know efficacy. Which areas of nerve and muscle are stimulated and are these areas adequate to cause incapacitation? This paper focuses on efficacy, which used a torso-sized finite element model with a mesh of about 5 mm. To estimate the neuromuscular regions stimulated by the Taser® X26, calculations of electric current density and field strength values with 1 A inserted into the torso using the Utah 3D mesh were made. Field-times-duration values for given Taser stimulation were calculated. Then the region where the motor nerve was stimulated by the Taser was estimated by using a field-times-duration threshold from Reilly (1998 Applied Bioelectricity: From Electrical Stimulation to Electropathology (New York: Springer)). Neuromuscular stimulation occurred up to about 19 cm away from the darts and included the spinal cord. The current density at the heart for dart separation less than 10 cm was smaller than for larger dart separation. Users of finite element computer models will find information for torso models and their creation, meshing and operation.

  12. Why Quantification Matters: Characterization of Phenotypes at the Drosophila Larval Neuromuscular Junction

    PubMed Central

    Pennetta, Giuseppa

    2016-01-01

    Most studies on morphogenesis rely on qualitative descriptions of how anatomical traits are affected by the disruption of specific genes and genetic pathways. Quantitative descriptions are rarely performed, although genetic manipulations produce a range of phenotypic effects and variations are observed even among individuals within control groups. Emerging evidence shows that morphology, size and location of organelles play a previously underappreciated, yet fundamental role in cell function and survival. Here we provide step-by-step instructions for performing quantitative analyses of phenotypes at the Drosophila larval neuromuscular junction (NMJ). We use several reliable immuno-histochemical markers combined with bio-imaging techniques and morphometric analyses to examine the effects of genetic mutations on specific cellular processes. In particular, we focus on the quantitative analysis of phenotypes affecting morphology, size and position of nuclei within the striated muscles of Drosophila larvae. The Drosophila larval NMJ is a valuable experimental model to investigate the molecular mechanisms underlying the structure and the function of the neuromuscular system, both in health and disease. However, the methodologies we describe here can be extended to other systems as well. PMID:27213489

  13. Maximum-likelihood q-estimator uncovers the role of potassium at neuromuscular junctions.

    PubMed

    da Silva, A J; Trindade, M A S; Santos, D O C; Lima, R F

    2016-02-01

    Recently, we demonstrated the existence of nonextensive behavior in neuromuscular transmission (da Silva et al. in Phys Rev E 84:041925, 2011). In this letter, we first obtain a maximum-likelihood q-estimator to calculate the scale factor ([Formula: see text]) and the q-index of q-Gaussian distributions. Next, we use the indexes to analyze spontaneous miniature end plate potentials in electrophysiological recordings from neuromuscular junctions. These calculations were performed assuming both normal and high extracellular potassium concentrations [Formula: see text]. This protocol was used to test the validity of Tsallis statistics under electrophysiological conditions closely resembling physiological stimuli. The analysis shows that q-indexes are distinct depending on the extracellular potassium concentration. Our letter provides a general way to obtain the best estimate of parameters from a q-Gaussian distribution function. It also expands the validity of Tsallis statistics in realistic physiological stimulus conditions. In addition, we discuss the physical and physiological implications of these findings.

  14. Neuromuscular dysfunction with the experimental arm acting as its own reference following eccentric and isometric exercise.

    PubMed

    Philippou, Anastassios; Bogdanis, Gregory C; Maridaki, Maria

    2010-01-01

    Eccentric exercise has been extensively used as a model to study muscle damage-induced neuromuscular impairment, adopting mainly a bilateral matching task between the reference (unexercised) arm and the indicator (exercised) arm. However, little attention has been given to the muscle proprioceptive function when the exercised arm acts as its own reference. This study investigated muscle proprioception and motor control, with the arm acting both as reference and indicator, following eccentric exercise and compared them with those observed after isometric exercise. Fourteen young male volunteers were equally divided into two groups and performed an eccentric or isometric exercise protocol with the elbow flexors of the non-dominant arm on an isokinetic dynamometer. Both exercise protocols induced significant changes in indicators of muscle damage, that is, muscle soreness, range of motion and maximal isometric force post-exercise (p < 0.05-0.001), and neuromuscular function was similarly affected following both protocols. Perception of force was impaired over the 4-day post-exercise period (p < 0.001), with the applied force being systematically overestimated. Perception of joint position was significantly disturbed (i.e., target angle was underestimated) only at one elbow angle on day 4 post-exercise (p < 0.05). The misjudgements and disturbed motor output observed when the exercised arm acted as its own reference concur with the view that they could be a result of a mismatch between the central motor command and an impaired motor control after muscle damage. PMID:20553224

  15. High intensity running results in an impaired neuromuscular response in ACL reconstructed individuals.

    PubMed

    Patras, Kostas; Ziogas, Giorgos; Ristanis, Stavros; Tsepis, Elias; Stergiou, Nicholas; Georgoulis, Anastasios D

    2009-08-01

    Anterior cruciate ligament (ACL) reconstruction reestablishes electromyographic activity during moderate activities such as walking but is unclear if this is also the case in sports activities such as high intensity running that results in accumulation of metabolic fatigue. Nine bone-patella tendon-bone ACL reconstructed athletes were evaluated 19.2 (5.7) months post-operatively using a telemetric electromyographic system. The neuromuscular response of vastus lateralis and biceps femoris muscles was tested bilaterally on separate occasions during 10 min running at moderate intensity (20% below the lactate threshold) and 10 min running at high intensity (40% above the lactate threshold). During moderate intensity running, electromyographic activity did not change for either leg. During high intensity running, electromyographic activity did not change for the vastus lateralis of the ACL reconstructed leg [267.8 (142.8)-263.8 (128.9) microV, P > 0.05] while it increased significantly [294.2 (120.6)-317.1 (140.5) microV, P = 0.03] for the vastus lateralis of the intact leg. High intensity exercise that is associated with accumulation of metabolic fatigue, results in an impaired neuromuscular response for the vastus lateralis muscle of the ACL reconstructed leg.

  16. Effect of fluid ingestion on neuromuscular function during prolonged cycling exercise

    PubMed Central

    Vallier, J; Grego, F; Basset, F; Lepers, R; Bernard, T; Brisswalter, J

    2005-01-01

    Objectives: To investigate the effects of fluid ingestion on neuromuscular function during prolonged cycling exercise. Methods: Eight well trained subjects exercised for 180 minutes in a moderate environment at a workload requiring ∼60% maximal oxygen uptake. Two conditions, fluid (F) and no fluid (NF) ingestion, were investigated. Results: During maximal voluntary isometric contraction (MVC), prolonged cycling exercise reduced (p<0.05) the maximal force generating capacity of quadriceps muscles (after three hours of cycling) and root mean square (RMS) values (after two hours of cycling) with no difference between the two conditions despite greater body weight loss (p<0.05) in NF. The mean power frequency (MPF) for vastus lateralis muscle was reduced (p<0.05) and the rate of force development (RFD) was increased (p<0.05) only during NF. During cycling exercise, integrated electromyographic activity and perceived exertion were increased in both conditions (p<0.05) with no significant effect of fluid ingestion. Conclusions: The results suggest that fluid ingestion did not prevent the previously reported decrease in maximal force with exercise duration, but seems to have a positive effect on some indicators of neuromuscular fatigue such as mean power frequency and rate of force development during maximal voluntary contraction. Further investigations are needed to assess the effect of change in hydration on neural mechanisms linked to the development of muscular fatigue during prolonged exercise. PMID:15793075

  17. Intravenous immunoglobulin in the treatment of autoimmune neuromuscular diseases: present status and practical therapeutic guidelines.

    PubMed

    Dalakas, M C

    1999-11-01

    This review summarizes the current status of intravenous immunoglobulin (IVIg) in the treatment of autoimmune neuromuscular disorders and the possible mechanisms of action of the drug based on work in vivo, in vitro, and in animal models. Supply of idiotypic antibodies, suppression of antibody production, or acceleration of catabolism of immunoglobulin G (IgG) are relevant in explaining the efficacy of IVIg in myasthenia gravis (MG), Lambert-Eaton myasthenic syndrome (LEMS), and antibody-mediated neuropathies. Suppression of pathogenic cytokines has putative relevance in inflammatory myopathies and demyelinating neuropathies. Inhibition of complement binding and prevention of membranolytic attack complex (MAC) formation are relevant in dermatomyositis (DM), Guillain-Barré syndrome (GBS), and MG. Modulation of Fc receptors or T-cell function is relevant in chronic inflammatory demyelinating polyneuropathy (CIDP), GBS, and inflammatory myopathies. The clinical efficacy of IVIg, based on controlled clinical trials conducted in patients with GBS, CIDP, multifocal motor neuropathy (MMN), DM, MG, LEMS, paraproteinemic IgM anti-myelin-associated glycoprotein (anti-MAG) demyelinating polyneuropathies, and inclusion body myositis is summarized and practical issues related to each disorder are addressed. The present role of IVIg therapy in other disorders based on small controlled or uncontrolled trials is also summarized. Finally, safety issues, risk factors, adverse reactions, spurious results or serological tests, and practical guidelines associated with the administration of IVIg in the treatment of neuromuscular disorders are presented.

  18. Agrin regulates CLASP2-mediated capture of microtubules at the neuromuscular junction synaptic membrane

    PubMed Central

    Schmidt, Nadine; Basu, Sreya; Sladecek, Stefan; Gatti, Sabrina; van Haren, Jeffrey; Treves, Susan; Pielage, Jan

    2012-01-01

    Agrin is the major factor mediating the neuronal regulation of postsynaptic structures at the vertebrate neuromuscular junction, but the details of how it orchestrates this unique three-dimensional structure remain unknown. Here, we show that agrin induces the formation of the dense network of microtubules in the subsynaptic cytoplasm and that this, in turn, regulates acetylcholine receptor insertion into the postsynaptic membrane. Agrin acted in part by locally activating phosphatidylinositol 3-kinase and inactivating GSK3β, which led to the local capturing of dynamic microtubules at agrin-induced acetylcholine receptor (AChR) clusters, mediated to a large extent by the microtubule plus-end tracking proteins CLASP2 and CLIP-170. Indeed, in the absence of CLASP2, microtubule plus ends at the subsynaptic muscle membrane, the density of synaptic AChRs, the size of AChR clusters, and the numbers of subsynaptic muscle nuclei with their selective gene expression programs were all reduced. Thus, the cascade linking agrin to CLASP2-mediated microtubule capturing at the synaptic membrane is essential for the maintenance of a normal neuromuscular phenotype. PMID:22851317

  19. Quisqualate-activated single channel currents in neuromuscular preparations of small and large crayfish.

    PubMed

    Finger, W; Martin, C; Pareto, A

    1988-06-01

    Single channel currents elicited by 1-5 mumol/l quisqualate in neuromuscular preparations in large (greater than 16 month old) and small (1-3 month old) crayfish were recorded by means of the patch-clamp technique. In preparations from large crayfish single channel currents of variable amplitude (-1 to -12 pA) were induced by quisqualate. The mean burst lengths of these currents were tau approximately equal to 1-2 ms. In the opener muscle of the first walking leg and the contractor epimeralis muscle of small crayfish the mean burst lengths of single channel currents evoked by quisqualate were prolonged by a factor of about 4 (tau approximately equal to 5 ms). Moreover, in the opener muscle of the first walking leg of small crayfish single channel currents of small amplitude (-0.5 to -2.5 pA) were preferentially evoked by quisqualate. By contrast, in the contractor epimeralis muscle of small crayfish mainly single channel currents of large amplitude (-10 to -12 pA) were elicited by quisqualate. The results suggest that at the stage of neuromuscular development characterizing the small crayfish, gating properties of excitatory postsynaptic channels are different from those in adult crayfish. Furthermore, the results obtained in the opener muscle of the first walking leg of small crayfish are consistent with those obtained previously by means of the noise analysis technique.

  20. [Screening for hereditary neuromuscular disorders with molecular genetic methods in the Roma population of Hungary].

    PubMed

    Herczegfalvi, Agnes; Pikó, Henriett; Karcagi, Veronika

    2008-11-30

    Recent medical genetic research has identified a number of novel, or previously known, but rare conditions, caused by private founder mutations. The Finnish and Ashkenazi Jew populations provide the best examples for identifying genes in unique genetic disorders. In these populations, research efforts and high-level medical services resulted in intense improvements of medical care and in organization of population-based screening programs. Hereditary disorders of the Roma populations are known for a long time. The genetic background of these diseases has been established by extensive molecular genetic studies. The Romas represent 6% of the Hungarian population and live under extremely bad health conditions. Therefore, our aim was to map the incidence of the hereditary neuromuscular disorders among the Hungarian Roma population. Moreover, we intended to provide proper information, genetic counseling and possible prevention strategies for the families at risk, which should represent a primer task in public health. Because of our experience in neuromuscular disorders, we choose six, frequent, autosomal recessive disorders for these clinical and genetic studies: hereditary motor and sensory neuropathy type Lom (HMSNL), hereditary motor and sensory neuropathy type Russe (HMSNR), congenital cataracts facial dysmorphism syndrome (CCFDN), limb-girdle muscular dystrophy 2C (LGMD2C), congenital myasthenic syndrome (CMS) and spinal muscular atrophy (SMA). Following identification of the founder mutations, the possibility of prenatal diagnosis and carrier screening for family members will contribute to the decrease of the recurrence risk for these severe, mostly untreatable disorders. PMID:19070320

  1. Current Trends in Neuromuscular Blockade, Management, and Monitoring amongst Singaporean Anaesthetists

    PubMed Central

    Tseng, Phillip S.

    2016-01-01

    Introduction. This survey aimed to investigate the attitudes/practice pertaining the use, management, and monitoring of neuromuscular blockade amongst Singaporean anaesthetists. Methods. All specialist accredited anaesthetists registered with the Singapore Medical Council were invited to complete an anonymous online survey. Results. The response rate was 39.5%. Neuromuscular monitoring (NM) was used routinely by only 13.1% despite the widespread availability of monitors. 82% stated residual NMB (RNMB) was a significant risk factor for patient outcome, but only 24% believed NMB monitoring should be compulsory in all paralyzed patients. 63.6% of anaesthetists estimated the risk of RNMB in their own institutions to be <5%. 63.1% always gave reversal. Neostigmine was predominantly used (85.1%), with 28.2% using sugammadex at least sometimes, citing unavailability and high costs. However, 83.8% believed in sugammadex's benefits for patients' safety and >50% said such benefits may be able to offset the associated costs. Conclusions. There is a significant need for reeducation about RNMB, studies on local RNMB incidences, and strengthening of current monitoring practices and guidelines. Strategies are discussed. As NM monitors appear widely available and reversal of NMB standard practice, it is hopeful that Singaporean anaesthetists will change and strive for evidence-based best clinical practice to enhance patient safety.

  2. Neuromuscular responses to mild-muscle damaging eccentric exercise in a low glycogen state.

    PubMed

    Gavin, James P; Myers, Stephen D; Willems, Mark E T

    2015-02-01

    The aim of this study was to examine the effect of low muscle glycogen on the neuromuscular responses to maximal eccentric contractions. Fourteen healthy men (22 ± 3 years) performed single-leg cycling (20 min at ~75% maximal oxygen uptake (V̇O2 max); eight 90 s sprints at a 1:1 work-to-rest ratio (5% decrements from 90% to 55% V̇O2 max until exhaustion) the evening before 100 eccentric (1.57 rads(-1)) with reduced (RED) and normal glycogen (NORM). Neuromuscular responses were measured during and up to 48 h after with maximal voluntary and involuntary (twitch, 20 Hz and 50 Hz) isometric contractions. During eccentric contractions, peak torque decreased (RED: -16.1 ± 2.5%; NORM: -6.2 ± 5.1%) and EMG frequency increased according to muscle length. EMG activity decreased for RED only. After eccentric contractions, maximal isometric force was reduced up to 24h for NORM (-13.5 ± 5.8%) and 48 h for RED (-7.4 ± 10.9%). Twelve hours after eccentric contractions, twitch force and the 20:50 Hz ratio were decreased for RED but not for NORM. Immediate involuntary with prolonged voluntary force loss suggests that reduced glycogen is associated with increased susceptibility to mild muscle-damaging eccentric exercise with contributions of peripheral and central mechanisms to be different during recovery.

  3. Muscles in a mouse model of spinal muscular atrophy show profound defects in neuromuscular development even in the absence of failure in neuromuscular transmission or loss of motor neurons

    PubMed Central

    Lee, Young il; Mikesh, Michelle; Smith, Ian; Rimer, Mendell; Thompson, Wesley

    2011-01-01

    A mouse model of the devastating human disease "spinal muscular atrophy" (SMA) was used to investigate the severe muscle weakness and spasticity that precedes the death of these animals near the end of the 2nd postnatal week. Counts of motor units to the soleus muscle as well as of axons in the soleus muscle nerve showed no loss of motor neurons. Similarly, neither immunostaining of neuromuscular junctions nor the measurement of the tension generated by nerve stimulation gave evidence of any significant impairment in neuromuscular transmission, even when animals were maintained up to 5 days longer via a supplementary diet. However, the muscles were clearly weaker, generating less than half their normal tension. Weakness in 3 muscles examined in the study appears due to a severe but uniform reduction in muscle fiber size. The size reduction results from a failure of muscle fibers to grow during early postnatal development and, in soleus, to a reduction in number of fibers generated. Neuromuscular development is severely delayed in these mutant animals: expression of myosin heavy chain isoforms, the elimination of polyneuronal innervation, the maturation in the shape of the AChR plaque, the arrival of SCs at the junctions and their coverage of the nerve terminal, the development of junctional folds. Thus, if SMA in this particular mouse is a disease of motor neurons, it can act in a manner that does not result in their death or disconnection from their targets but nonetheless alters many aspects of neuromuscular development. PMID:21658376

  4. Muscles in a mouse model of spinal muscular atrophy show profound defects in neuromuscular development even in the absence of failure in neuromuscular transmission or loss of motor neurons.

    PubMed

    Lee, Young Il; Mikesh, Michelle; Smith, Ian; Rimer, Mendell; Thompson, Wesley

    2011-08-15

    A mouse model of the devastating human disease "spinal muscular atrophy" (SMA) was used to investigate the severe muscle weakness and spasticity that precede the death of these animals near the end of the 2nd postnatal week. Counts of motor units to the soleus muscle as well as of axons in the soleus muscle nerve showed no loss of motor neurons. Similarly, neither immunostaining of neuromuscular junctions nor the measurement of the tension generated by nerve stimulation gave evidence of any significant impairment in neuromuscular transmission, even when animals were maintained up to 5days longer via a supplementary diet. However, the muscles were clearly weaker, generating less than half their normal tension. Weakness in 3 muscles examined in the study appears due to a severe but uniform reduction in muscle fiber size. The size reduction results from a failure of muscle fibers to grow during early postnatal development and, in soleus, to a reduction in number of fibers generated. Neuromuscular development is severely delayed in these mutant animals: expression of myosin heavy chain isoforms, the elimination of polyneuronal innervation, the maturation in the shape of the AChR plaque, the arrival of SCs at the junctions and their coverage of the nerve terminal, the development of junctional folds. Thus, if SMA in this particular mouse is a disease of motor neurons, it can act in a manner that does not result in their death or disconnection from their targets but nonetheless alters many aspects of neuromuscular development.

  5. Neuromuscular Stress.

    ERIC Educational Resources Information Center

    White, Timothy P.; Kern, Marialice

    1994-01-01

    Discusses exercise-induced stress that results from motor unit recruitment, the impact of recruitment on selected systemic support systems, and some of the environmental overlays that affect the degree of physiological stress. Adaptations to sustained changes in physical activity and muscle and myotendinous injury induced by stress are examined.…

  6. Assessing Activity Limitations in Patients with Neuromuscular Diseases: Is the ACTIVLIM Questionnaire Linked to ICF and ICF-CY?

    ERIC Educational Resources Information Center

    Raggi, Alberto; Leonardi, Matilde

    2009-01-01

    The objective of this study was to explore to what extent the ACTIVLIM questionnaire, designed to evaluate limitations in activities involving upper and lower limbs in adults and children with neuromuscular diseases, is linked to the domains of the Activities and Participation of the International Classification of Functioning, Disability and…

  7. Acute effect of scapular proprioceptive neuromuscular facilitation (PNF) techniques and classic exercises in adhesive capsulitis: a randomized controlled trial.

    PubMed

    Balcı, Nilay Comuk; Yuruk, Zeliha Ozlem; Zeybek, Aslican; Gulsen, Mustafa; Tekindal, Mustafa Agah

    2016-04-01

    [Purpose] The aim of our study was to compare the initial effects of scapular proprioceptive neuromuscular facilitation techniques and classic exercise interventions with physiotherapy modalities on pain, scapular dyskinesis, range of motion, and function in adhesive capsulitis. [Subjects and Methods] Fifty-three subjects were allocated to 3 groups: scapular proprioceptive neuromuscular facilitation exercies and physiotherapy modalities, classic exercise and physiotherapy modalities, and only physiotherapy modalities. The intervention was applied in a single session. The Visual Analog Scale, Lateral Scapular Slide Test, range of motion and Simple Shoulder Test were evaluated before and just after the one-hour intervention in the same session (all in one session). [Results] All of the groups showed significant differences in shoulder flexion and abduction range of motion and Simple Shoulder Test scores. There were statistically significant differences in Visual Analog Scale scores in the proprioceptive neuromuscular facilitation and control groups, and no treatment method had significant effect on the Lateral Scapular Slide Test results. There were no statistically significant differences between the groups before and after the intervention. [Conclusion] Proprioceptive neuromuscular facilitation, classic exercise, and physiotherapy modalities had immediate effects on adhesive capsulitis in our study. However, there was no additional benefit of exercises in one session over physiotherapy modalities. Also, an effective treatment regimen for shoulder rehabilitation of adhesive capsulitis patients should include scapular exercises.

  8. Noninvasive Mechanical Ventilation Improves Breathing-Swallowing Interaction of Ventilator Dependent Neuromuscular Patients: A Prospective Crossover Study

    PubMed Central

    Garguilo, Marine; Lejaille, Michèle; Vaugier, Isabelle; Orlikowski, David; Terzi, Nicolas; Lofaso, Frédéric; Prigent, Hélène

    2016-01-01

    Background Respiratory involvement in neuromuscular disorders may contribute to impaired breathing-swallowing interactions, swallowing disorders and malnutrition. We investigated whether the use of non-invasive ventilation (NIV) controlled by the patient could improve swallowing performances in a population of neuromuscular patients requiring daytime NIV. Methods Ten neuromuscular patients with severe respiratory failure requiring extensive NIV use were studied while swallowing without and with NIV (while ventilated with a modified ventilator allowing the patient to withhold ventilation as desired). Breathing-swallowing interactions were investigated by chin electromyography, cervical piezoelectric sensor, nasal flow recording and inductive plethysmography. Two water-bolus sizes (5 and 10ml) and a textured yogurt bolus were tested in a random order. Results NIV use significantly improved swallowing fragmentation (defined as the number of respiratory interruption of the swallowing of a single bolus) (p = 0.003) and breathing-swallowing synchronization (with a significant increase of swallows followed by an expiration) (p <0.0001). Patient exhibited piecemeal swallowing which was not influenced by NIV use (p = 0.07). NIV use also significantly reduced dyspnea during swallowing (p = 0.04) while preserving swallowing comfort, regardless of bolus type. Conclusion The use of patient controlled NIV improves swallowing parameters in patients with severe neuromuscular respiratory failure requiring daytime NIV, without impairing swallowing comfort. Trial Registration ClinicalTrials.gov NCT01519388 PMID:26938617

  9. Acute effect of scapular proprioceptive neuromuscular facilitation (PNF) techniques and classic exercises in adhesive capsulitis: a randomized controlled trial

    PubMed Central

    Balcı, Nilay Comuk; Yuruk, Zeliha Ozlem; Zeybek, Aslican; Gulsen, Mustafa; Tekindal, Mustafa Agah

    2016-01-01

    [Purpose] The aim of our study was to compare the initial effects of scapular proprioceptive neuromuscular facilitation techniques and classic exercise interventions with physiotherapy modalities on pain, scapular dyskinesis, range of motion, and function in adhesive capsulitis. [Subjects and Methods] Fifty-three subjects were allocated to 3 groups: scapular proprioceptive neuromuscular facilitation exercies and physiotherapy modalities, classic exercise and physiotherapy modalities, and only physiotherapy modalities. The intervention was applied in a single session. The Visual Analog Scale, Lateral Scapular Slide Test, range of motion and Simple Shoulder Test were evaluated before and just after the one-hour intervention in the same session (all in one session). [Results] All of the groups showed significant differences in shoulder flexion and abduction range of motion and Simple Shoulder Test scores. There were statistically significant differences in Visual Analog Scale scores in the proprioceptive neuromuscular facilitation and control groups, and no treatment method had significant effect on the Lateral Scapular Slide Test results. There were no statistically significant differences between the groups before and after the intervention. [Conclusion] Proprioceptive neuromuscular facilitation, classic exercise, and physiotherapy modalities had immediate effects on adhesive capsulitis in our study. However, there was no additional benefit of exercises in one session over physiotherapy modalities. Also, an effective treatment regimen for shoulder rehabilitation of adhesive capsulitis patients should include scapular exercises. PMID:27190456

  10. Effect of 50% enantiomeric excess bupivacaine mixture combined with pancuronium on neuromuscular transmission in rat phrenic nerve-diaphragm preparation; a pilot study

    PubMed Central

    de Assunção Braga, Angelica de Fátima; Carvalho, Vanessa Henriques; da Silva Braga, Franklin Sarmento; Potério, Gloria Maria Braga; Santos, Filipe Nadir Caparica; Junqueira, Fernando Eduardo Féres

    2015-01-01

    Background and Aims: Local anaesthetics are drugs that are widely used in clinical practice. However, the effects of these drugs on the neuromuscular junction and their influence on the blockade produced by non-depolarising neuromuscular blocking drugs are still under investigation. The aim of this study was to evaluate, in vitro, the influence of a 50% enantiomeric excess bupivacaine mixture on neuromuscular transmission and neuromuscular block produced by pancuronium. Methods: Rats were distributed into three groups (n = 5) according to the drug studied namely, 50% enantiomeric excess bupivacaine mixture (5 μg/mL); pancuronium (2 μg/mL); 50% enantiomeric excess bupivacaine mixture + pancuronium. The following parameters were evaluated: (1) Effects of a 50% enantiomeric excess bupivacaine mixture on membrane potential (MP) and miniature endplate potentials (MEPPs); (2) amplitude of diaphragmatic response before and 60 min after the addition of a 50% enantiomeric excess bupivacaine mixture; the degree of neuromuscular block with pancuronium and pancuronium combined with a 50% enantiomeric excess bupivacaine mixture. Results: A 50% enantiomeric excess bupivacaine mixture did not alter the amplitude of muscle response (MP) but decreased the frequency and amplitude of MEPP. The block produced by pancuronium was potentiated by a 50% enantiomeric excess bupivacaine mixture. Conclusion: A 50% enantiomeric excess bupivacaine mixture used alone did not affect neuromuscular transmission, but potentiated the neuromuscular block produced by pancuronium. No action was shown on the muscle fibre, and alterations on MEPPs demonstrated a presynaptic action. PMID:26755834

  11. Professional Soccer Player Neuromuscular Responses and Perceptions to Acute Whole Body Vibration Differ from Amateur Counterparts

    PubMed Central

    Cloak, Ross; Lane, Andrew; Wyon, Matthew

    2016-01-01

    Acute whole body vibration (WBV) is an increasingly popular training technique amongst athletes immediately prior to performance and during scheduled breaks in play. Despite its growing popularity, evidence to demonstrate its effectiveness on acute neuromuscular responses is unclear, and suggestions that athlete ability impacts effectiveness warrant further investigation. The purpose of this study was to compare the neuromuscular effects of acute WBV and perceptions of whether WBV is an effective intervention between amateur and professional soccer players. Participants were 44 male soccer players (22 professional and 22 amateur; age: 23.1 ± 3.7 years, body mass: 75.6 ± 8.8 kg and height: 1.77 ± 0.05 m). Participants in each group were randomly assigned to either an intervention of 3 x 60 s of WBV at 40 Hz (8mm peak-to-peak displacement) or control group. Peak knee isometric force, muscle activation and post activation potentiation (PAP) of the knee extensors along with self-report questionnaire of the perceived benefits of using the intervention were collected. A three-way ANOVA with repeated measures revealed professional players demonstrated a significant 10.6% increase (p < 0.01, Partial Eta2 = 0.22) in peak knee isometric force following acute WBV with no significant differences among amateur players. A significant difference (p < 0.01, Partial Eta2 = 0.16) in PAP amongst professional players following acute WBVT was also reported. No significant differences amongst amateur players were reported across measurements. Results also indicated professional players reported significantly stronger positive beliefs in the effectiveness of the WBV intervention (p < 0.01, Partial Eta2 = 0.27) compared to amateur players. Acute WBV elicited a positive neuromuscular response amongst professional players identified by PAP and improvements in knee isometric peak force as well as perceived benefits of the intervention, benefits not found among amateur players. Key points

  12. Early neuromuscular customized training after surgery for lumbar disc herniation: a prospective controlled study.

    PubMed

    Millisdotter, Monica; Strömqvist, Björn

    2007-01-01

    A prospective and controlled study of training after surgery for lumbar disc herniation (LDH). The objective was to determine the effect of early neuromuscular customized training after LDH surgery. No consensus exists on the type and timing of physical rehabilitation after LDH surgery. Patients aged 15-50 years, disc prolapse at L4-L5 or L5-S1. Before surgery, at 6 weeks, 4, and 12 months postoperatively, the following evaluations were performed: low back pain and leg pain estimated on a visual analog scale, disability according to the Roland-Morris questionnaire (RMQ) and disability rating index (DRI). Clinical examination, including the SLR test, was performed using a single blind method. Consumption of analgesics was registered. Twenty-five patients started neuromuscular customized training 2 weeks after surgery (early training group = ETG). Thirty-one patients formed a control group (CG) and started traditional training after 6 weeks. There was no significant difference in pain and disability between the two training groups before surgery. Median preoperative leg pain was 63 mm in ETG and 70 mm in the CG. Preoperative median disability according to RMQ was 14 in the ETG and 14.5 in the CG. Disability according to DRI (33/56 patients) was 5.3 in the ETG vs. 4.6 in the CG. At 6 weeks, 4 months, and 12 months, pain was significantly reduced in both groups, to the same extent. Disability scores were lower in the ETG at all follow-ups, and after 12 months, the difference was significant (RMQ P=.034, DRI P=.015). The results of the present study show early neuromuscular customized training to have a superior effect on disability, with a significant difference compared to traditional training at a follow-up 12 months after surgery. No adverse effects of the early training were seen. A prospective, randomized study with a larger patient sample is warranted to ultimately demonstrate that early training as described is beneficial for patients undergoing LDH surgery

  13. Vellozia flavicans Mart. ex Schult. hydroalcoholic extract inhibits the neuromuscular blockade induced by Bothrops jararacussu venom

    PubMed Central

    2014-01-01

    Background Snakebite is a significant public health issue in tropical countries. In Brazil, some of the most common snake envenomations are from Bothrops. Bothrops bites trigger local and systemic effects including edema, pain, erythema, cyanosis, infections, and necrosis. Vellozia flavicans is a plant from the Brazilian “cerrado” (savanna) that is popularly used as an anti-inflammatory medicine. Since inflammation develops quickly after Bothrops bites, which can lead to infection, the aim of the present study was to observe possible anti-snake venom and antimicrobial activities of V. flavicans (Vf). Methods The chromatographic profile of the main constituents from the Vf leaf hydroalcoholic extract was obtained by thin-layer chromatography (TLC). The anti-snake venom activity was measured by Vf’s ability to neutralize the in vitro neuromuscular blockade caused by Bothrops jararacussu venom (Bjssu) in a mouse phrenic nerve-diaphragm model (PND). After a 20 min incubation, preparations of PND were added to Tyrode’s solution (control); Vf (0.2, 0.5, 1, and 2 mg/mL); 40 μg/mL Bjssu; pre-incubation for 30 min with Bjssu and 1 mg/mL Vf; and a Bjssu pretreated preparation (for 10 min) followed by 1 mg/mL Vf. Myographic recording was performed, and the contractile responses were recorded. The antimicrobial activity (minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC]) was obtained for Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus faecalis, using gentamicin and vancomycin as positive controls. Results TLC analysis yielded several compounds from Vf, such as flavonoids (quercetin) and phenolic acids (chlorogenic acid). Bjssu completely blocked the contractile responses of PND preparations, while Vf preserved 97% (±10%) of the contractile responses when incubated with Bjssu. In the PND pretreated with Bjssu, Vf was able to inhibit the neuromuscular blockade progress. MIC and MBC of Vf ranged

  14. Action of Micrurus dumerilii carinicauda coral snake venom on the mammalian neuromuscular junction.

    PubMed

    Serafim, Francine G; Reali, Marielga; Cruz-Höfling, Maria Alice; Fontana, Marcos D

    2002-02-01

    The venoms of coral snakes (mainly Micrurus species) have pre- and/or postsynaptic actions, but only a few of these have been studied in detail. We have investigated the effects of Micrurus dumerilii carinicauda coral snake venom on neurotransmission in rat isolated phrenic nerve-diaphragm muscle and chick biventer cervicis preparations stimulated directly or indirectly. M. d. carinicauda venom (5 or 10 microg/ml) produced neuromuscular blockade in rat (85-90% in 291.8+/-7.3 min and 108.3+/-13.8, respectively; n=5) and avian (95.0+/-2.0 min; 5 microg/ml, n=5) preparations. Neostigmine (5.8 microM) and 3,4-diaminopyridine (230 microM) partially reversed the venom-induced neuromuscular blockade in rat nerve-muscle preparations. In neither preparation did the venom depress the twitch response elicited by direct muscle stimulation. The contractures induced by acetylcholine in chick preparations were inhibited by the venom (95-100%; n=4; p<0.05). In rat preparations, the venom produced a progressive decrease in the amplitude of miniature end-plate potentials (m.e.p.ps control frequency=69.3+/-5.0/min and control amplitude=0.4+/-0.2 mV) until these were abolished. Neostigmine (5.8 microM) and 3,4-diaminopyridine (230 microM) partially antagonized this blockade of m.e.p.ps. The resting membrane potential was not altered with the venom (10 microg/ml). M. d. carinicauda venom produced dose-dependent morphological changes in indirectly stimulated mammal preparations. Twenty-five per cent of muscle fibers were affected by a venom concentration of 5 microg/ml, whilst 60.7% were damaged by 10 microg of venom/ml. In biventer cervicis preparations, the morphological changes were slower in onset and were generally characterized by undulating fibers and, to a lesser extent, by zones of disintegrating myofibrils. A venom concentration of 5 microg/ml damaged 52.2% of the fibers. These findings indicate that M. d. carinicauda venom has neurotoxic and myotoxic effects and that the

  15. Neuromuscular Fatigue and Physiological Responses After Five Dynamic Squat Exercise Protocols.

    PubMed

    Raeder, Christian; Wiewelhove, Thimo; Westphal-Martinez, Marc P; Fernandez-Fernandez, Jaime; de Paula Simola, Rauno A; Kellmann, Michael; Meyer, Tim; Pfeiffer, Mark; Ferrauti, Alexander

    2016-04-01

    This aimed to analyze neuromuscular, physiological and perceptual responses to a single bout of 5 different dynamic squat exercise protocols. In a randomized and counterbalanced order, 15 male resistance-trained athletes (mean ± SD; age: 23.1 ± 1.9 years, body mass: 77.4 ± 8.0 kg) completed traditional multiple sets (MS: 4 × 6, 85% 1 repetition maximum [RM]), drop sets (DS: 1 × 6, 85% 1RM + 3 drop sets), eccentric overload (EO: 4 × 6, 70% 1RM concentric, 100% 1RM eccentric), flywheel YoYo squat (FW: 4 × 6, all-out), and a plyometric jump protocol (PJ: 4 × 15, all-out). Blood lactate (La), ratings of perceived exertion (RPE), counter movement jump height (CMJ), multiple rebound jump (MRJ) performance, maximal voluntary isometric contraction force, serum creatine kinase (CK) and delayed onset muscle soreness were measured. Immediately post exercise, La was significantly (p < 0.001) higher in FW (mean ± 95% confidence limit; 12.2 ± 0.9 mmol·L) and lower in PJ (3.0 ± 0.8 mmol·L) compared with MS (7.7 ± 1.5 mmol·L), DS (8.5 ± 0.6 mmol·L), and EO (8.2 ± 1.6 mmol·L), accompanied by similar RPE responses. Neuromuscular performance (CMJ, MRJ) significantly remained decreased (p < 0.001) from 0.5 to 48 hours post exercise in all protocols. There was a significant time × protocol interaction (p ≤ 0.05) in MRJ with a significant lower performance in DS, EO, and FW compared with PJ (0.5 hours post exercise), and in EO compared with all other protocols (24 hours post exercise). A significant main time effect with peak values 24 hours post exercise was observed in CK serum concentrations (p < 0.001), but there was no time × protocol interaction. In conclusion, (a) metabolic and perceptual demands were higher in FW and EO compared with MS, DS and PJ, (b) neuromuscular fatigue was consistent up to 48 hours post exercise in all protocols, and PMID:26349042

  16. Early neuromuscular customized training after surgery for lumbar disc herniation: a prospective controlled study

    PubMed Central

    Strömqvist, Björn

    2006-01-01

    A prospective and controlled study of training after surgery for lumbar disc herniation (LDH). The objective was to determine the effect of early neuromuscular customized training after LDH surgery. No consensus exists on the type and timing of physical rehabilitation after LDH surgery. Patients aged 15–50 years, disc prolapse at L4–L5 or L5–S1. Before surgery, at 6 weeks, 4, and 12 months postoperatively, the following evaluations were performed: low back pain and leg pain estimated on a visual analog scale, disability according to the Roland–Morris questionnaire (RMQ) and disability rating index (DRI). Clinical examination, including the SLR test, was performed using a single blind method. Consumption of analgesics was registered. Twenty-five patients started neuromuscular customized training 2 weeks after surgery (early training group=ETG). Thirty-one patients formed a control group (CG) and started traditional training after 6 weeks. There was no significant difference in pain and disability between the two training groups before surgery. Median preoperative leg pain was 63 mm in ETG and 70 mm in the CG. Preoperative median disability according to RMQ was 14 in the ETG and 14.5 in the CG. Disability according to DRI (33/56 patients) was 5.3 in the ETG vs. 4.6 in the CG. At 6 weeks, 4 months, and 12 months, pain was significantly reduced in both groups, to the same extent. Disability scores were lower in the ETG at all follow-ups, and after 12 months, the difference was significant (RMQ P=.034, DRI P=.015). The results of the present study show early neuromuscular customized training to have a superior effect on disability, with a significant difference compared to traditional training at a follow-up 12 months after surgery. No adverse effects of the early training were seen. A prospective, randomized study with a larger patient sample is warranted to ultimately demonstrate that early training as described is beneficial for patients undergoing LDH

  17. A six-week neuromuscular training program for competitive junior tennis players.

    PubMed

    Barber-Westin, Sue D; Hermeto, Alex A; Noyes, Frank R

    2010-09-01

    This study evaluated the effectiveness of a tennis-specific training program on improving neuromuscular indices in competitive junior players. Tennis is a demanding sport because it requires speed, agility, explosive power, and aerobic conditioning along with the ability to react and anticipate quickly, and there are limited studies that evaluate these indices in young players after a multiweek training program. The program designed for this study implemented the essential components of a previously published neuromuscular training program and also included exercises designed to improve dynamic balance, agility, speed, and strength. Fifteen junior tennis players (10 girls, 5 boys; mean age, 13.0 +/- 1.5 years) who routinely participated in local tournaments and high-school teams participated in the 6-week supervised program. Training was conducted 3 times a week, with sessions lasting 1.5 hours that included a dynamic warm-up, plyometric and jump training, strength training (lower extremity, upper extremity, core), tennis-specific drills, and flexibility. After training, statistically significant improvements and large-to-moderate effect sizes were found in the single-leg triple crossover hop for both legs (p < 0.05), the baseline forehand (p = 0.006) and backhand (p = 0.0008) tests, the service line (p = 0.0009) test, the 1-court suicide (p < 0.0001), the 2-court suicide (p = 0.02), and the abdominal endurance test (p = 0.01). Mean improvements between pretrain and posttrain test sessions were 15% for the single-leg triple crossover hop, 10-11% for the baseline tests, 18% for the service line test, 21% for the 1-court suicide, 10% for the 2-court suicide, and 76% for the abdominal endurance test. No athlete sustained an injury or developed an overuse syndrome as a result of the training program. The results demonstrate that this program is feasible, low in cost, and appears to be effective in improving the majority of neuromuscular indices tested. We accomplished

  18. Cross‐disease comparison of amyotrophic lateral sclerosis and spinal muscular atrophy reveals conservation of selective vulnerability but differential neuromuscular junction pathology

    PubMed Central

    Nijssen, Jik; Frost‐Nylen, Johanna

    2015-01-01

    Neuromuscular junctions are primary pathological targets in the lethal motor neuron diseases spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS). Synaptic pathology and denervation of target muscle fibers has been reported prior to the appearance of clinical symptoms in mouse models of both diseases, suggesting that neuromuscular junctions are highly vulnerable from the very early stages, and are a key target for therapeutic intervention. Here we examined neuromuscular pathology longitudinally in three clinically relevant muscle groups in mouse models of ALS and SMA in order to assess their relative vulnerabilities. We show for the first time that neuromuscular junctions of the extraocular muscles (responsible for the control of eye movement) were resistant to degeneration in endstage SMA mice, as well as in late symptomatic ALS mice. Tongue muscle neuromuscular junctions were also spared in both animal models. Conversely, neuromuscular junctions of the lumbrical muscles of the hind‐paw were vulnerable in both SMA and ALS, with a loss of neuronal innervation and shrinkage of motor endplates in both diseases. Thus, the pattern of selective vulnerability was conserved across these two models of motor neuron disease. However, the first evidence of neuromuscular pathology occurred at different timepoints of disease progression, with much earlier evidence of presynaptic involvement in ALS, progressing to changes on the postsynaptic side. Conversely, in SMA changes appeared concomitantly at the neuromuscular junction, suggesting that mechanisms of neuromuscular disruption are distinct in these diseases. J. Comp. Neurol. 524:1424–1442, 2016. © 2015 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc. PMID:26502195

  19. From Neuromuscular Activation to End-point Locomotion: An Artificial Neural Network-based Technique for Neural Prostheses

    PubMed Central

    Chang, Chia-Lin; Jin, Zhanpeng; Chang, Hou-Cheng; Cheng, Allen C.

    2009-01-01

    Neuroprostheses, implantable or non-invasive ones, are promising techniques to enable paralyzed individuals with conditions, such as spinal cord injury or spina bifida (SB), to control their limbs voluntarily. Direct cortical control of invasive neuroprosthetic devices and robotic arms have recently become feasible for primates. However, little is known about designing non-invasive, closed-loop neuromuscular control strategies for neural prostheses. Our goal was to investigate if an Artificial Neural Network-based (ANN-based) model for closed-loop controlled neural prostheses could use neuromuscular activation recorded from individuals with impaired spinal cord to predict their end-point gait parameters (such as stride length and step width). We recruited 12 persons with SB (5 females and 7 males) and collected their neuromuscular activation and end-point gait parameters during overground walking. Our results show that the proposed ANN-based technique can achieve a highly accurate prediction (e.g., R-values of 0.92 – 0.97, ANN (tansig+tansig) for single composition of data sets) for altered end-point locomotion. Compared to traditional robust regression, this technique can provide up to 80% more accurate prediction. Our results suggest that more precise control of complex neural prostheses during locomotion can be achieved by engaging neuromuscular activity as intrinsic feedback to generate end-point leg movement. This ANN-based model allows a seamless incorporation of neuromuscular activity, detected from paralyzed individuals, to adaptively predict their altered gait patterns, which can be employed to provide closed-loop feedback information for neural prostheses. PMID:19389678

  20. Perisynaptic Schwann Cells at the Neuromuscular Synapse: Adaptable, Multitasking Glial Cells.

    PubMed

    Ko, Chien-Ping; Robitaille, Richard

    2015-10-01

    The neuromuscular junction (NMJ) is engineered to be a highly reliable synapse to carry the control of the motor commands of the nervous system over the muscles. Its development, organization, and synaptic properties are highly structured and regulated to support such reliability and efficacy. Yet, the NMJ is also highly plastic, able to react to injury and adapt to changes. This balance between structural stability and synaptic efficacy on one hand and structural plasticity and repair on another hand is made possible by the intricate regulation of perisynaptic Schwann cells, glial cells at this synapse. They regulate both the efficacy and structural plasticity of the NMJ in a dynamic, bidirectional manner owing to their ability to decode synaptic transmission and by their interactions via trophic-related factors.

  1. Hormones and the neuromuscular control of courtship in the golden-collared manakin (Manacus vitellinus)

    PubMed Central

    Schlinger, Barney A.; Barske, Julia; Day, Lainy; Fusani, Leonida; Fuxjager, Matthew J.

    2014-01-01

    Many animals engage in spectacular courtship displays, likely recruiting specialized neural, hormonal and muscular systems to facilitate these performances. Male golden-collared manakins (Manacus vitellinus) of Panamanian rainforests perform physically elaborate courtship displays that include novel forms of visual and acoustic signaling. We study the behavioral neuroendocrinology of this male’s courtship, combining field behavioral observations with anatomical, biochemical and molecular laboratory-based studies. Seasonally, male courtship is activated by testosterone with little correspondence between testosterone levels and display intensity. Females prefer males whose displays are exceptionally frequent, fast and accurate. The activation of androgen receptors (AR) is crucial for optimal display performance, with AR expressed at elevated levels in several neuromuscular tissues. Apparently, courtship enlists an elaborate androgen-dependent network that includes spinal motoneurons, skeletal muscles and somatosensory systems. This work highlights the value of studying non-traditional species to illuminate physiological adaptations and, hopefully, stimulates future research on other species with complex behaviors. PMID:23624091

  2. Hormones and the neuromuscular control of courtship in the golden-collared manakin (Manacus vitellinus).

    PubMed

    Schlinger, Barney A; Barske, Julia; Day, Lainy; Fusani, Leonida; Fuxjager, Matthew J

    2013-08-01

    Many animals engage in spectacular courtship displays, likely recruiting specialized neural, hormonal and muscular systems to facilitate these performances. Male golden-collared manakins (Manacus vitellinus) of Panamanian rainforests perform physically elaborate courtship displays that include novel forms of visual and acoustic signaling. We study the behavioral neuroendocrinology of this male's courtship, combining field behavioral observations with anatomical, biochemical and molecular laboratory-based studies. Seasonally, male courtship is activated by testosterone with little correspondence between testosterone levels and display intensity. Females prefer males whose displays are exceptionally frequent, fast and accurate. The activation of androgen receptors (AR) is crucial for optimal display performance, with AR expressed at elevated levels in several neuromuscular tissues. Apparently, courtship enlists an elaborate androgen-dependent network that includes spinal motoneurons, skeletal muscles and somatosensory systems. This work highlights the value of studying non-traditional species to illuminate physiological adaptations and, hopefully, stimulates future research on other species with complex behaviors. PMID:23624091

  3. The Neuromuscular Junction: Aging at the Crossroad between Nerves and Muscle

    PubMed Central

    Gonzalez-Freire, Marta; de Cabo, Rafael; Studenski, Stephanie A.; Ferrucci, Luigi

    2014-01-01

    Aging is associated with a progressive loss of muscle mass and strength and a decline in neurophysiological functions. Age-related neuromuscular junction (NMJ) plays a key role in musculoskeletal impairment that occurs with aging. However, whether changes in the NMJ precede or follow the decline of muscle mass and strength remains unresolved. Many factors such as mitochondrial dysfunction, oxidative stress, inflammation, changes in the innervation of muscle fibers, and mechanical properties of the motor units probably perform an important role in NMJ degeneration and muscle mass and strength decline in late life. This review addresses the primary events that might lead to NMJ dysfunction with aging, including studies on biomarkers, signaling pathways, and animal models. Interventions such as caloric restriction and exercise may positively affect the NMJ through this mechanism and attenuate the age-related progressive impairment in motor function. PMID:25157231

  4. Monte Carlo simulation of miniature endplate current generation in the vertebrate neuromuscular junction.

    PubMed Central

    Bartol, T M; Land, B R; Salpeter, E E; Salpeter, M M

    1991-01-01

    A Monte Carlo method for modeling the neuromuscular junction is described in which the three-dimensional structure of the synapse can be specified. Complexities can be introduced into the acetylcholine kinetic model used with only a small increase in computing time. The Monte Carlo technique is shown to be superior to differential equation modeling methods (although less accurate) if a three-dimensional representation of synaptic geometry is desired. The conceptual development of the model is presented and the accuracy estimated. The consequences of manipulations such as varying the spacing of secondary synaptic folds or that between the release of multiple quantal packets of acetylcholine, are also presented. Increasing the spacing between folds increases peak current. Decreased spacing of adjacent quantal release sites increases the potentiation of peak current. Images FIGURE 1 FIGURE 1 FIGURE 7 FIGURE 8 FIGURE 10 FIGURE 11 PMID:1873466

  5. Coordinated motor neuron axon growth and neuromuscular synaptogenesis are promoted by CPG15 in vivo.

    PubMed

    Javaherian, Ashkan; Cline, Hollis T

    2005-02-17

    We have used in vivo time-lapse two-photon imaging of single motor neuron axons labeled with GFP combined with labeling of presynaptic vesicle clusters and postsynaptic acetylcholine receptors in Xenopus laevis tadpoles to determine the dynamic rearrangement of individual axon branches and synaptogenesis during motor axon arbor development. Control GFP-labeled axons are highly dynamic during the period when axon arbors are elaborating. Axon branches emerge from sites of synaptic vesicle clusters. These data indicate that motor neuron axon elaboration and synaptogenesis are concurrent and iterative. We tested the role of Candidate Plasticity Gene 15 (CPG15, also known as Neuritin), an activity-regulated gene that is expressed in the developing motor neurons in this process. CPG15 expression enhances the development of motor neuron axon arbors by promoting neuromuscular synaptogenesis and by increasing the addition of new axon branches. PMID:15721237

  6. Brain-controlled neuromuscular stimulation to drive neural plasticity and functional recovery.

    PubMed

    Ethier, C; Gallego, J A; Miller, L E

    2015-08-01

    There is mounting evidence that appropriately timed neuromuscular stimulation can induce neural plasticity and generate functional recovery from motor disorders. This review addresses the idea that coordinating stimulation with a patient's voluntary effort might further enhance neurorehabilitation. Studies in cell cultures and behaving animals have delineated the rules underlying neural plasticity when single neurons are used as triggers. However, the rules governing more complex stimuli and larger networks are less well understood. We argue that functional recovery might be optimized if stimulation were modulated by a brain machine interface, to match the details of the patient's voluntary intent. The potential of this novel approach highlights the need for a better understanding of the complex rules underlying this form of plasticity. PMID:25827275

  7. LRRK2 regulates retrograde synaptic compensation at the Drosophila neuromuscular junction

    PubMed Central

    Penney, Jay; Tsurudome, Kazuya; Liao, Edward H.; Kauwe, Grant; Gray, Lindsay; Yanagiya, Akiko; R. Calderon, Mario; Sonenberg, Nahum; Haghighi, A. Pejmun

    2016-01-01

    Parkinson's disease gene leucine-rich repeat kinase 2 (LRRK2) has been implicated in a number of processes including the regulation of mitochondrial function, autophagy and endocytic dynamics; nevertheless, we know little about its potential role in the regulation of synaptic plasticity. Here we demonstrate that postsynaptic knockdown of the fly homologue of LRRK2 thwarts retrograde, homeostatic synaptic compensation at the larval neuromuscular junction. Conversely, postsynaptic overexpression of either the fly or human LRRK2 transgene induces a retrograde enhancement of presynaptic neurotransmitter release by increasing the size of the release ready pool of vesicles. We show that LRRK2 promotes cap-dependent translation and identify Furin 1 as its translational target, which is required for the synaptic function of LRRK2. As the regulation of synaptic homeostasis plays a fundamental role in ensuring normal and stable synaptic function, our findings suggest that aberrant function of LRRK2 may lead to destabilization of neural circuits. PMID:27432119

  8. An upper body exercise system incorporating resistive exercise and neuromuscular electrical stimulation (NMS).

    PubMed

    Cameron, T; Broton, J G; Needham-Shropshire, B; Klose, K J

    1998-01-01

    A device is described which combines arm crank ergometry and neuromuscular electrical stimulation (NMS) delivered at different phases of the crank cycle. Details of the device including circuit schematics are shown. The device was evaluated by non-paralyzed subjects for its operational safety and by tetraplegic subjects for its effectiveness as a muscle-strengthening tool. All subjects showed improvement in one or more of their manual muscle scores. The most dramatic increased motor score occurred in the triceps muscle group. There was an average increase in the manual muscle score of 1.1 +/- 0.2 for the left triceps and 0.7 +/- 0.1 for the right triceps after eight weeks of NMS assisted exercise. No adverse effects were experienced and it appears to meet safety considerations necessary for this group of individuals. Preliminary observations indicate that an eight-week exercise protocol that utilizes this device can be beneficial for this population. PMID:9541880

  9. The neuromuscular blocking properties of a series of bis-quaternary tropeïnes

    PubMed Central

    Haining, C. G.; Johnston, R. G.; Smith, J. M.

    1960-01-01

    Linkage of two tropine esters through their nitrogen atoms by the chain -[CH2]m-O-CO-[CH2]n-CO-O-[CH2]m-, in which m was 2 or 3 and n varied from 0 to 6, gave compounds which produced neuromuscular block without depolarization. Reversibility be neostigmine was confirmed for a few compounds. Potency was found to depend upon the tropine ester employed and upon the values of n and m. Short duration and hypotensive properties were favoured by the higher values of n. The duration of action of the compound based on the phenylacetic acid ester of tropine, in which n=4 and m=2, varied considerably in different species. Epimerization, in which the relative positions of the methyl group and the linking chain on the quaternary tropane nitrogen atom were reversed, did not produce subtances having more favourable properties than those possessed by the unepimerized compounds. PMID:14398886

  10. Aging Drosophila melanogaster display altered pre- and postsynaptic ultrastructure at adult neuromuscular junctions.

    PubMed

    Wagner, Nicole; Laugks, Ulrike; Heckmann, Manfred; Asan, Esther; Neuser, Kirsa

    2015-11-01

    Although age-related changes in synaptic plasticity are an important focus within neuroscience, little is known about ultrastructural changes of synaptic morphology during aging. Here we report how aging affects synaptic ultrastructure by using fluorescence and electron microscopy at the adult Drosophila neuromuscular junction (NMJ) of ventral abdominal muscles. Mainly four striking morphological changes of aging NMJs were revealed. 1) Bouton size increases with proportionally rising number of active zones (AZs). 2) Synaptic vesicle density at AZs is increased in old flies. 3) Late endosomes, cisternae, and multivesicular bodies accumulate in the presynaptic terminal, and vesicles accumulate between membranes of the terminal bouton and the subsynaptic reticulum. 4) The electron-dense pre- and postsynaptic apposition is expanded in aging NMJs, which is accompanied by an expansion of the postsynaptic glutamate receptor fields. These findings suggest that aging is possibly accompanied by impaired synaptic vesicle release and recycling and a potentially compensatory expansion of AZs and postsynaptic densities. PMID:25940748

  11. Pharmacotherapy to protect the neuromuscular junction after acute organophosphorus pesticide poisoning.

    PubMed

    Bird, Steven B; Krajacic, Predrag; Sawamoto, Keigo; Bunya, Naofumi; Loro, Emanuele; Khurana, Tejvir S

    2016-06-01

    Organophosphorus (OP) pesticide poisoning is a leading cause of morbidity and mortality in the developing world, affecting an estimated three million people annually. Much of the morbidity is directly related to muscle weakness, which develops 1-4 days after poisoning. This muscle weakness, termed the intermediate syndrome (IMS), leads to respiratory, bulbar, and proximal limb weakness and frequently necessitates the use of mechanical ventilation. While not entirely understood, the IMS is most likely due to persistently elevated acetylcholine (ACh), which activates nicotinic ACh receptors at the neuromuscular junction (NMJ). Thus, the NMJ is potentially a target-rich area for the development of new therapies for acute OP poisoning. In this manuscript, we discuss what is known about the IMS and studies investigating the use of nicotinic ACh receptor antagonists to prevent or mitigate NMJ dysfunction after acute OP poisoning. PMID:27258847

  12. Perisynaptic Schwann Cells at the Neuromuscular Synapse: Adaptable, Multitasking Glial Cells.

    PubMed

    Ko, Chien-Ping; Robitaille, Richard

    2015-10-01

    The neuromuscular junction (NMJ) is engineered to be a highly reliable synapse to carry the control of the motor commands of the nervous system over the muscles. Its development, organization, and synaptic properties are highly structured and regulated to support such reliability and efficacy. Yet, the NMJ is also highly plastic, able to react to injury and adapt to changes. This balance between structural stability and synaptic efficacy on one hand and structural plasticity and repair on another hand is made possible by the intricate regulation of perisynaptic Schwann cells, glial cells at this synapse. They regulate both the efficacy and structural plasticity of the NMJ in a dynamic, bidirectional manner owing to their ability to decode synaptic transmission and by their interactions via trophic-related factors. PMID:26430218

  13. Neuromuscular and biomechanical landing performance subsequent to ipsilateral semitendinosus and gracilis autograft anterior cruciate ligament reconstruction.

    PubMed

    Vairo, Giampietro L; Myers, Joseph B; Sell, Timothy C; Fu, Freddie H; Harner, Christopher D; Lephart, Scott M

    2008-01-01

    The hamstrings musculature is a vital component of an intricate dynamic knee joint restraint mechanism. However, there is evidence based on research studies suggesting potential deficits to this complex mechanism due to donor site morbidity resulting from harvest of the ipsilateral semitendinosus and gracilis autograft (ISGA) for anterior cruciate ligament reconstruction (ACLR). The purpose of this retrospective research study was to investigate the effects of ISGA ACLR on neuromuscular and biomechanical performance during a single-leg vertical drop landing (VDL), a functional task and associated mechanism of anterior cruciate ligament disruption during physical activity. Fourteen physically active participants 22.5 +/- 4.1 years of age and 21.4 +/- 10.7 months post ISGA ACLR underwent bilateral neuromuscular, biomechanical and isokinetic strength and endurance evaluations matched to 14 control participants by sex, age, height and mass. Kinetic and kinematic data was obtained with 3-D motion analyses utilizing inverse dynamics while performing single-leg VDLs from a height of 30 cm. Integrated surface electromyography (SEMG) assessments of the quadriceps, hamstrings and gastrocnemius musculature were also conducted. Additionally, knee joint flexion strength (60 degrees s(-1)) and endurance (240 degrees s(-1)) measurements were tested via isokinetic dynamometry. No significant differences existed in hip and net summated extensor moments within or between groups. The ISGA ACLR participants recorded significantly decreased peak vertical ground reaction force (VGRF) landing upon the involved lower extremity compared to uninvolved (P = 0.028) and matched (P < 0.0001) controls. Participants having undergone ISGA ACLR also displayed greater peak hip joint flexion angles landing upon the involved lower extremity compared to uninvolved (P = 0.020) and matched (P = 0.026) controls at initial ground contact. The ISGA ACLR group furthermore exhibited increased peak hip joint

  14. [Neuromuscular effects of superimposed and combined transcutaneous electrical stimulation with voluntary activity: a review].

    PubMed

    Paillard, T; Noé, F; Edeline, O

    2005-04-01

    With voluntary muscular contraction (VOL), small motor units (MUs) are recruited before large MUs are (a submaximal muscular contraction recruits only small MUs), whereas electrical stimulation (ES) tends to reverse the recruitment order. On the basis of this observation, some authors have tested the physiological effects of ES superimposed simultaneously with VOL (superimposed technique [ST]) or separately (combined technique [CT]). With healthy subjects, ST does not recruit more MUs than VOL, except with eccentric contractions. After health subjects undergo training programs, ST appears to be as efficient as VOL in enhancing subjects' neuromuscular qualities. Nevertheless, the use of CT seems more effective than VOL. In postsurgical rehabilitation, both ST and CT are more effective than VOL. Actually, following knee surgery, ST and CT compensate for volume and muscle strength deficits with more efficiency than does VOL.

  15. Reliability of a Test Battery Designed for Quickly and Safely Assessing Diverse Indices of Neuromuscular Function

    NASA Technical Reports Server (NTRS)

    Spiering, Barry A.; Lee, Stuart M. C.; Mulavara, Ajitkumar P.; Bentley, Jason, R.; Buxton, Roxanne E.; Lawrence, Emily L.; Sinka, Joseph; Guilliams, Mark E.; Ploutz-Snyder, Lori L.; Bloomberg, Jacob J.

    2010-01-01

    Spaceflight affects nearly every physiological system. Spaceflight-induced alterations in physiological function translate to decrements in functional performance. Purpose: To develop a test battery for quickly and safely assessing diverse indices of neuromuscular performance. I. Quickly: Battery of tests can be completed in approx.30-40 min. II. Safely: a) No eccentric muscle actions or impact forces. b) Tests present little challenge to postural stability. III. Diverse indices: a) Strength: Excellent reliability (ICC = 0.99) b) Central activation: Very good reliability (ICC = 0.87) c) Power: Excellent reliability (ICC = 0.99) d) Endurance: Total work has excellent reliability (ICC = 0.99) e) Force steadiness: Poor reliability (ICC = 0.20 - 0.60) National

  16. Neuromuscular Risk Factors for Knee and Ankle Ligament Injuries in Male Youth Soccer Players.

    PubMed

    Read, Paul J; Oliver, Jon L; De Ste Croix, Mark B A; Myer, Gregory D; Lloyd, Rhodri S

    2016-08-01

    Injuries reported in male youth soccer players most commonly occur in the lower extremities, and include a high proportion of ligament sprains at the ankle and knee with a lower proportion of overuse injuries. There is currently a paucity of available literature that examines age- and sex-specific injury risk factors for such injuries within youth soccer players. Epidemiological data have reported movements that lead to non-contact ligament injury include running, twisting and turning, over-reaching and landing. Altered neuromuscular control during these actions has been suggested as a key mechanism in females and adult populations; however, data available in male soccer players is sparse. The focus of this article is to review the available literature and elucidate prevalent risk factors pertaining to male youth soccer players which may contribute to their relative risk of injury. PMID:26856339

  17. Structure and Activation of MuSK, a Receptor Tyrosine Kinase Central to Neuromuscular Junction Formation

    PubMed Central

    Hubbard, Stevan R.; Gnanasambandan, Kavitha

    2014-01-01

    MuSK (muscle-specific kinase) is a receptor tyrosine kinase that plays a central signaling role in formation of neuromuscular junctions (NMJs). MuSK is activated in a complex spatio-temporal manner to cluster acetylcholine receptors on the postsynaptic (muscle) side of the synapse and to induce differentiation of the nerve terminal on the presynaptic side. The ligand for MuSK is LRP4 (low-density lipoprotein receptor-related protein-4), a transmembrane protein in muscle, whose binding affinity for MuSK is potentiated by agrin, a neuronally derived heparan-sulfate proteoglycan. In addition, Dok7, a cytoplasmic adaptor protein, is also required for MuSK activation in vivo. This review focuses on the physical interplay between these proteins and MuSK for activation and downstream signaling, which culminates in NMJ formation. PMID:23467009

  18. Crosstalk between Agrin and Wnt signaling pathways in development of vertebrate neuromuscular junction.

    PubMed

    Barik, Arnab; Zhang, Bin; Sohal, Gurkirpal S; Xiong, Wen-Cheng; Mei, Lin

    2014-08-01

    Neuromuscular junction (NMJ) is a cholinergic synapse where motor neurons elicit muscle contraction. Agrin and its coreceptors LRP4 and MuSK are critical for vertebrate NMJ formation. This paper reviews recent evidence for Wnts and Wnt signaling molecules in NMJ formation including a possible retrograde mechanism by muscle β-catenin. We also present data that Wnt3a, 7a, 8a and 10b could inhibit agrin-mediated AChR clustering. Together with the stimulating effect of Wnt9a, 9b, 10b, 11 and 16 on AChR clustering in the absence of agrin, these results suggest diverse roles for Wnt ligands in NMJ development. PMID:24838312

  19. The neuro-muscular system in fresh-water furcocercaria from Belarus. I Schistosomatidae.

    PubMed

    Tolstenkov, Oleg O; Akimova, Ludmila N; Chrisanfova, Galina G; Terenina, Nadezhda B; Gustafsson, Margaretha K S

    2012-01-01

    The neuro-muscular system (NMS) in cercariae of the family Schistosomatidae from Belarus was studied with immunocytochemical methods and confocal scanning laser microscopy. The specimens of Bilharziella polonica were compared with Trichobilharzia szidati and Trichobilharzia franki. The patterns of F-actin in the musculature, 5-HT-immunoreactive (IR), FMRFamide-IR neuronal elements and α-tubulin-IR in sensory receptors and nerves were investigated. No indications of structural differences in the musculature, the 5-HT-IR, FMRF-IR neuronal elements and the general distribution of sensory receptors were noticed between cercariae of Trichobilharzia spp. The number of 5-HT-IR neurons in the cercarial bodies is 16. In cercaria B. polonica, the tail musculature is weaker than in Trichobilharzia spp. A detailed schematic picture of the NMS in the tail of Trichobilharzia spp. cercaria is given. The function of NMS elements in the tail is discussed.

  20. The neuro-muscular system in continuously swimming cercariae from Belarus. I Xiphidiocercariae.

    PubMed

    Tolstenkov, Oleg O; Akimova, Ludmila N; Terenina, Nadezhda B; Gustafsson, Margaretha K S

    2012-11-01

    The neuromuscular system (NMS) in cercariae of Neoastiotrema trituri, Plagiorchis elegans, Omphalometra flexuosa, Skrjabinoeces similis and Prosthogonimus ovatus was studied with immunocytochemical methods and confocal scanning laser microscopy. The patterns of F-actin in the musculature, 5-HT immunoreactive (IR), FMRFamide-IR neuronal elements and α-tubulin-IR sensory receptors were investigated, and they were found to be rather similar in all the cercariae studied. Four species have seven paired 5-HT-IR neurons in the body, and P. elegans has eight. N. trituri has three 5-HT-IR neurons in each brain ganglion, while the other species have four. A high degree of conformity in the structure of the NMS was observed, probably reflecting the close phylogenetic relationship and the similar strategy of host finding.

  1. In vitro microelectrode study of neuromuscular transmission in a case of botulism.

    PubMed

    Maselli, R A; Burnett, M E; Tonsgard, J H

    1992-03-01

    We performed in vitro microelectrode studies in the anconeus muscle biopsy of a 6-week-old infant intoxicated with Clostridium botulinum toxin B. The most striking abnormalities were the severe reduction of the endplate potential (EPP) quantal content and the marked variability of EPP latencies. The increased variability was often limited to a "single quantum" component of the EPP. Neither the amplitudes nor the frequencies of spontaneous miniature endplate potentials (MEEPs) were decreased. However, there was a wide range of amplitudes and frequencies of MEPPs. This unique combination of electrophysiologic findings indicates a severe presynaptic failure of neuromuscular transmission, which appears to result from an impairment of the process of synaptic vesicle release taking place after the stimulus induced influx of calcium into the motor nerve terminals.

  2. Human neuromuscular structure and function in old age: A brief review

    PubMed Central

    Power, Geoffrey A.; Dalton, Brian H.; Rice, Charles L.

    2016-01-01

    Natural adult aging is associated with many functional impairments of the human neuromuscular system. One of the more observable alterations is the loss of contractile muscle mass, termed sarcopenia. The loss of muscle mass occurs primarily due to a progressive loss of viable motor units, and accompanying atrophy of remaining muscle fibers. Not only does the loss of muscle mass contribute to impaired function in old age, but alterations in fiber type and myosin heavy chain isoform expression also contribute to weaker, slower, and less powerful contracting muscles. This review will focus on motor unit loss associated with natural adult aging, age-related fatigability, and the age-related differences in strength across contractile muscle actions. PMID:27011872

  3. Brain-Controlled Neuromuscular Stimulation to Drive Neural Plasticity and Functional Recovery

    PubMed Central

    Ethier, C.; Gallego, J.A.; Miller, L.E.

    2015-01-01

    There is mounting evidence that appropriately timed neuromuscular stimulation can induce neural plasticity and generate functional recovery from motor disorders. This review addresses the idea that coordinating stimulation with a patient’s voluntary effort might further enhance neurorehabilitation. Studies in cell cultures and behaving animals have delineated the rules underlying neural plasticity when single neurons are used as triggers. However, the rules governing more complex stimuli and larger networks are less well understood. We argue that functional recovery might be optimized if stimulation were modulated by a brain machine interface, to matched the details of the patient’s voluntary intent. The potential of this novel approach highlights the need for a better understanding of the complex rules underlying this form of plasticity. PMID:25827275

  4. Carbohydrate vs protein supplementation for recovery of neuromuscular function following prolonged load carriage

    PubMed Central

    2010-01-01

    Background This study examined the effect of carbohydrate and whey protein supplements on recovery of neuromuscular function after prolonged load carriage. Methods Ten male participants (body mass: 81.5 ± 10.5 kg, age: 28 ± 9 years, O2max: 55.0 ± 5.5 ml·kg-1·min-1) completed three treadmill walking tests (2 hr, 6.5 km·h-1), carrying a 25 kg backpack consuming 500 ml of either: (1) Placebo (flavoured water) [PLA], (2) 6.4% Carbohydrate Solution [CHO] or (3) 7.0% Whey Protein Solution [PRO]. For three days after load carriage, participants consumed two 500 ml supplement boluses. Muscle performance was measured before and at 0, 24, 48 and 72 h after load carriage, during voluntary and electrically stimulated contractions. Results Isometric knee extension force decreased immediately after load carriage with no difference between conditions. During recovery, isometric force returned to pre-exercise values at 48 h for CHO and PRO but at 72 h for PLA. Voluntary activation decreased immediately after load carriage and returned to pre-exercise values at 24 h in all conditions (P = 0.086). During recovery, there were no differences between conditions for the change in isokinetic peak torque. Following reductions immediately after load carriage, knee extensor and flexor peak torque (60°·s-1) recovered to pre-exercise values at 72 h. Trunk extensor and flexor peak torque (15°·s-1) recovered to pre-exercise values at 24 h (P = 0.091) and 48 h (P = 0.177), respectively. Conclusion Recovery of neuromuscular function after prolonged load carriage is improved with either carbohydrate or whey protein supplementation for isometric contractions but not for isokinetic contractions. PMID:20157419

  5. Stabilization of acetylcholine receptors at the neuromuscular synapse: the role of the nerve.

    PubMed

    Ramsay, D A; Drachman, D B; Drachman, R J; Stanley, E F

    1992-05-29

    The majority of acetylcholine receptors (AChRs) at innervated neuromuscular junctions (NMJs) are stable, with half-lives averaging about 11 days in rodent muscles. In addition to the stable AChRs, approximately 18% of AChRs at these innervated junctions are rapidly turned over (RTOs), with half lives of less than 24 h. We have postulated that RTOs may be precursors of stable AChRs, and that the motor nerve may influence their stabilization. This hypothesis was tested by: (i) labeling AChRs in mouse sternomastoid (SM) muscles with 125I-alpha-BuTx; (ii) denervating one SM muscle in each mouse, and (iii) following the fate of the labeled AChRs through a 5-day period when RTOs were either stabilized or degraded. The hypothesis predicts that denervation should preclude stabilization of RTOs, resulting in a deficit of stable AChRs in denervated muscles. The results showed a highly significant (P less than 0.002) deficit of stable AChRs in denervated as compared with innervated muscles. Control experiments excluded the possibility that this deficit could be attributed to independent accelerated degradation of either RTOs or pre-existing stable AChRs. The observed deficit was quantitatively consistent with the deficit predicted by a mathematical model based on interruption of stabilization following denervation. We conclude that: (i) the observed deficit after denervation of NMJs is due to failure of stabilization of pre-existing RTOs; (ii) RTOs at normally innervated NMJs are precursors of stable AChRs; (iii) stabilization occurs after the insertion of AChRs at NMJs, and (iv) motor nerves play a key role in stabilization of RTOs. The concept of receptor stabilization has important implications for understanding the biology of the neuromuscular junction and post-synaptic plasticity.

  6. Effect of Patterned Electrical Neuromuscular Stimulation on Vertical Jump in Collegiate Athletes

    PubMed Central

    Gulick, Dawn T.; Castel, John C.; Palermo, Francis X.; Draper, David O.

    2011-01-01

    Background: Patterned electrical neuromuscular stimulation (PENS) uses the electrical stimulation of sensory and motor nerves to achieve a skeletal muscle contraction using an electromyogram-derived functional pattern. PENS is used extensively for neuromuscular reeducation and treatment of muscle disuse atrophy. Purpose: To explore the effectiveness of PENS as applied to the quadriceps muscles on the vertical jump of an athletic population. Study Design: Experimental with control and repeated measures over time. Methods: Healthy college athletes (54 women, 75 men) were divided into 3 groups (control, n = 30; jump, n = 33; and jump with PENS, n = 63). There was no difference among groups’ height and weight. Athletes performed a baseline standing vertical jump using a vertical jump system. The control group continued its normal daily activities with no jumping tasks included. The jump groups performed 3 sets of 12 repetitions with a 2-minute rest between sets at a frequency of 3 times per week. The PENS group did the jumping with the coordination of an electrical stimulation system. Vertical jump was retested after 6 weeks of intervention and 2 weeks after cessation. Results: A 3-way repeated measures analysis of variance for time (control, jump alone, jump with PENS) revealed a significant difference (P < 0.05) for time and an interaction between time and treatment, as well as a significant difference for the PENS group from baseline to posttest and for the jump group from posttest to follow-up jump. There was no significant difference between groups for the baseline vertical jump. Conclusions: This study demonstrated that 6 weeks of vertical jump training coordinated with PENS resulted in a greater increase than jumping only or control. This pattern of stimulation with PENS in combination with jump training may positively affect jumping. PMID:23016002

  7. Impaired Axonal Na+ Current by Hindlimb Unloading: Implication for Disuse Neuromuscular Atrophy

    PubMed Central

    Banzrai, Chimeglkham; Nodera, Hiroyuki; Kawarai, Toshitaka; Higashi, Saki; Okada, Ryo; Mori, Atsuko; Shimatani, Yoshimitsu; Osaki, Yusuke; Kaji, Ryuji

    2016-01-01

    This study aimed to characterize the excitability changes in peripheral motor axons caused by hindlimb unloading (HLU), which is a model of disuse neuromuscular atrophy. HLU was performed in normal 8-week-old male mice by fixing the proximal tail by a clip connected to the top of the animal's cage for 3 weeks. Axonal excitability studies were performed by stimulating the sciatic nerve at the ankle and recording the compound muscle action potential (CMAP) from the foot. The amplitudes of the motor responses of the unloading group were 51% of the control amplitudes [2.2 ± 1.3 mV (HLU) vs. 4.3 ± 1.2 mV (Control), P = 0.03]. Multiple axonal excitability analysis showed that the unloading group had a smaller strength-duration time constant (SDTC) and late subexcitability (recovery cycle) than the controls [0.075 ± 0.01 (HLU) vs. 0.12 ± 0.01 (Control), P < 0.01; 5.4 ± 1.0 (HLU) vs. 10.0 ± 1.3 % (Control), P = 0.01, respectively]. Three weeks after releasing from HLU, the SDTC became comparable to the control range. Using a modeling study, the observed differences in the waveforms could be explained by reduced persistent Na+ currents along with parameters related to current leakage. Quantification of RNA of a SCA1A gene coding a voltage-gated Na+ channel tended to be decreased in the sciatic nerve in HLU. The present study suggested that axonal ion currents are altered in vivo by HLU. It is still undetermined whether the dysfunctional axonal ion currents have any pathogenicity on neuromuscular atrophy or are the results of neural plasticity by atrophy. PMID:26909041

  8. A comparison of assisted and unassisted proprioceptive neuromuscular facilitation techniques and static stretching.

    PubMed

    Maddigan, Meaghan E; Peach, Ashley A; Behm, David G

    2012-05-01

    A comparison of assisted and unassisted proprioceptive neuromuscular facilitation techniques and static stretching. J Strength Cond Res 26(5): 1238-1244, 2012-Proprioceptive neuromuscular facilitation (PNF) stretching often requires a partner. Straps are available allowing an individual to perform PNF stretching alone. It is not known if a strap provides similar improvements in the range of motion (ROM) as partner-assisted PNF or static stretching. The purpose of this study was to compare assisted and unassisted (with a strap) PNF stretching and static stretching. Hip joint ROM, reaction time (RT), and movement time (MT) were measured prestretching and poststretching. Thirteen recreationally active adults participated in this study. The participants were subjected to 5 different stretch interventions in a random order on separate days. Stretch conditions included unassisted PNF stretching using (a) isometric, (b) concentric, and (c) eccentric contractions with a stretch strap, (d) partner-assisted isometric PNF, and (e) static stretching. The RT, MT, dynamic, active, passive hip flexion angle, and angular velocity with dynamic hip flexion were measured before and after the intervention. The ROM improved (p < 0.05) 2.6, 2.7, and 5.4%, respectively, with dynamic, active static, and passive static ROM, but there was no significant difference between the stretching protocols. There was a main effect for time (p < 0.05) with all stretching conditions negatively impacting dynamic angular velocity (9.2%). Although there was no significant effect on RT, MT showed a negative main effect for time (p < 0.05) slowing 3.4%. In conclusion, it was found that all 3 forms of active stretching provided similar improvements in the ROM and poststretching performance decrements in MT and angular velocity. Thus, individuals can implement PNF stretching techniques with a partner or alone with a strap to improve ROM, but athletes should not use these techniques before important

  9. Age-related changes in neuromuscular function of the quadriceps muscle in physically active adults.

    PubMed

    Mau-Moeller, Anett; Behrens, Martin; Lindner, Tobias; Bader, Rainer; Bruhn, Sven

    2013-06-01

    Substantial evidence exists for the age-related decline in maximal strength and strength development. Despite the importance of knee extensor strength for physical function and mobility in the elderly, studies focusing on the underlying neuromuscular mechanisms of the quadriceps muscle weakness are limited. The aim of this study was to investigate the contributions of age-related neural and muscular changes in the quadriceps muscle to decreases in isometric maximal voluntary torque (iMVT) and explosive voluntary strength. The interpolated twitch technique and normalized surface electromyography (EMG) signal during iMVT were analyzed to assess changes in neural drive to the muscles of 15 young and 15 elderly volunteers. The maximal rate of torque development as well as rate of torque development, impulse and neuromuscular activation in the early phase of contraction were determined. Spinal excitability was estimated using the H reflex technique. Changes at the muscle level were evaluated by analyzing the contractile properties and lean mass. The age-related decrease in iMVT was accompanied by a decline in voluntary activation and normalized surface EMG amplitude. Mechanical parameters of explosive voluntary strength were reduced while the corresponding muscle activation remained primarily unchanged. The spinal excitability of the vastus medialis was not different while M wave latency was longer. Contractile properties and lean mass were reduced. In conclusion, the age-related decline in iMVT of the quadriceps muscle might be due to a reduced neural drive and changes in skeletal muscle properties. The decrease in explosive voluntary strength seemed to be more affected by muscular than by neural changes. PMID:23453325

  10. Effect of resistance training on neuromuscular junctions of young and aged muscles featuring different recruitment patterns.

    PubMed

    Deschenes, Michael R; Sherman, E Grace; Roby, Mackenzie A; Glass, Emily K; Harris, M Brennan

    2015-03-01

    To examine the effects of aging on neuromuscular adaptations to resistance training (i.e., weight lifting), young (9 months of age) and aged (20 months of age) male rats either participated in a 7-week ladder climbing protocol with additional weight attached to their tails or served as controls (n = 10/group). At the conclusion, rats were euthanized and hindlimb muscles were quickly removed and frozen for later analysis. Longitudinal sections of the soleus and plantaris muscles were collected, and pre- and postsynaptic features of neuromuscular junctions (NMJs) were visualized with immunofluorescence staining procedures. Cross-sections of the same muscles were histochemically stained to determine myofiber profiles (fiber type and size). Statistical analysis was by two-way ANOVA (main effects of age and treatment) with significance set at P ≤ 0.05. Results revealed that training-induced remodeling of NMJs was evident only at the postsynaptic endplate region of soleus fast-twitch myofibers. In contrast, aging was associated with pre- and postsynaptic remodeling in fast- and slow-twitch myofibers of the plantaris. Although both the soleus and the plantaris muscles failed to display either training or aging-related alterations in myofiber size, aged plantaris muscles exhibited an increased expression of type I (slow-twitch) myofibers in conjunction with a reduced percentage of type II (fast-twitch) myofibers, suggesting early stages of sarcopenia. These data demonstrate the high degree of specificity of synaptic modifications made in response to exercise and aging and that the sparsely recruited plantaris is more vulnerable to the effects of aging than the more frequently recruited soleus muscle.

  11. Neuromuscular fatigue during high-intensity intermittent exercise in individuals with intellectual disability.

    PubMed

    Borji, Rihab; Sahli, Sonia; Zarrouk, Nidhal; Zghal, Firas; Rebai, Haithem

    2013-12-01

    This study examined neuromuscular fatigue after high-intensity intermittent exercise in 10 men with mild intellectual disability (ID) in comparison with 10 controls. Both groups performed three maximal voluntary contractions (MVC) of knee extension with 5 min in-between. The highest level achieved was selected as reference MVC. The fatiguing exercise consists of five sets with a maximal number of flexion-extension cycles at 80% of the one maximal repetition (1RM) for the right leg at 90° with 90 s rest interval between sets. The MVC was tested again after the last set. Peak force and electromyography (EMG) signals were measured during the MVC tests. Root Mean Square (RMS) and Median Frequency (MF) were calculated. Neuromuscular efficiency (NME) was calculated as the ratio of peak force to the RMS. Before exercise, individuals with ID had a lower MVC (p<0.05) and a lower RMS (p<0.05). No significant difference between groups in MF and NME. After exercise, MVC decreases significantly in both groups (p<0.001). Individuals with ID have greater force decline (p<0.001 vs. p<0.01). RMS decreased significantly (p<0.001) whereas the NME increased significantly (p<0.05) in individuals with ID, but both remained unchanged in controls. The MF decreased significantly in both groups (p<0.001). In conclusion, individuals with ID presented a lower peak force than individuals without ID. After a high-intensity intermittent exercise, individuals with ID demonstrated a greater force decline caused by neural activation failure. When rehabilitation and sport train ID individuals, they should consider this nervous system weakness.

  12. Recovery of mouse neuromuscular junctions from single and repeated injections of botulinum neurotoxin A

    PubMed Central

    Rogozhin, A A; Pang, K K; Bukharaeva, E; Young, C; Slater, C R

    2008-01-01

    Botulinum neurotoxin type A (BoNT/A) paralyses muscles by blocking acetylcholine (ACh) release from motor nerve terminals. Although highly toxic, it is used clinically to weaken muscles whose contraction is undesirable, as in dystonias. The effects of an injection of BoNT/A wear off after 3–4 months so repeated injections are often used. Recovery of neuromuscular transmission is accompanied by the formation of motor axon sprouts, some of which form new synaptic contacts. However, the functional importance of these new contacts is unknown. Using intracellular and focal extracellular recording we show that in the mouse epitrochleoanconeus (ETA), quantal release from the region of the original neuromuscular junction (NMJ) can be detected as soon as from new synaptic contacts, and generally accounts for > 80% of total release. During recovery the synaptic delay and the rise and decay times of endplate potentials (EPPs) become prolonged approximately 3-fold, but return to normal after 2–3 months. When studied after 3–4 months, the response to repetitive stimulation at frequencies up to 100 Hz is normal. When two or three injections of BoNT/A are given at intervals of 3–4 months, quantal release returns to normal values more slowly than after a single injection (11 and 15 weeks to reach 50% of control values versus 6 weeks after a single injection). In addition, branching of the intramuscular muscular motor axons, the distribution of the NMJs and the structure of many individual NMJs remain abnormal. These findings highlight the plasticity of the mammalian NMJ but also suggest important limits to it. PMID:18467364

  13. Leg Amyotrophic Diplegia: Prevalence and Pattern of Weakness at US Neuromuscular Centers

    PubMed Central

    Dimachkie, Mazen M.; Muzyka, Iryna M.; Katz, Jonathan S.; Jackson, Carlayne; Wang, Yunxia; McVey, April L.; Dick, Arthur; Pasnoor, Mamatha; Mozaffar, M. Tahseen; Xiao-Song, Z.; Kissel, John T.; Ensrud, E.; Rosenfeld, Jeffrey; Barohn, Richard J.

    2014-01-01

    Objective To identify the frequency of leg amyotrophic diplegia (LAD) at a US academic center, describe the pattern of weakness, and provide comparative data from 8 additional major US academic institutions. Background LAD is a leg onset variant of progressive muscular atrophy (PMA). LAD weakness is confined to the legs for at least 2 years and there are no upper motor neuron signs. Design/Methods We present a retrospective chart review of 24 patients with the LAD presentation from the University of Kansas Medical Center (KUMC, n=8 cases) and from eight US academic institutions (n=16 cases). Results Of 318 subjects identified in the KUMC Neuromuscular Research Database, 82% (260) had amyotrophic lateral sclerosis (ALS), 1.9% (6) had familial ALS, 6.6% (21) had primary lateral sclerosis, and 29 had LMN disease. Of these 29 cases, 16 had PMA, 5 had brachial amyotrophic diplegia, while 8 had LAD. The mean LAD age of onset was 58 years with a male/female ratio of 3/1. Onset was asymmetric in 7/8. We identified a pelviperoneal pattern of weakness (sparing of knee extension and/or ankle plantar flexion) in 4 cases and distal predominant weakness in 3. All patients had electrodiagnostic findings consistent with motor neuron disease confined to the lower extremities. We present LAD disease duration and survival data from eight major academic neuromuscular centers. At last follow up, weakness progressed to involve the arms in 6/24 LAD cases and of those two died from progression to typical ALS. From onset of symptoms, mean survival in LAD is 87 months, with 92% of cases being alive. Conclusions/Relevance The natural history of LAD differs from typical forms of ALS and PMA. LAD is a slowly progressive disorder that accounts for a fourth of LMN disease cases. An asymmetric pelviperoneal pattern of weakness should heighten the suspicion for LAD. PMID:23965403

  14. Impaired Axonal Na(+) Current by Hindlimb Unloading: Implication for Disuse Neuromuscular Atrophy.

    PubMed

    Banzrai, Chimeglkham; Nodera, Hiroyuki; Kawarai, Toshitaka; Higashi, Saki; Okada, Ryo; Mori, Atsuko; Shimatani, Yoshimitsu; Osaki, Yusuke; Kaji, Ryuji

    2016-01-01

    This study aimed to characterize the excitability changes in peripheral motor axons caused by hindlimb unloading (HLU), which is a model of disuse neuromuscular atrophy. HLU was performed in normal 8-week-old male mice by fixing the proximal tail by a clip connected to the top of the animal's cage for 3 weeks. Axonal excitability studies were performed by stimulating the sciatic nerve at the ankle and recording the compound muscle action potential (CMAP) from the foot. The amplitudes of the motor responses of the unloading group were 51% of the control amplitudes [2.2 ± 1.3 mV (HLU) vs. 4.3 ± 1.2 mV (Control), P = 0.03]. Multiple axonal excitability analysis showed that the unloading group had a smaller strength-duration time constant (SDTC) and late subexcitability (recovery cycle) than the controls [0.075 ± 0.01 (HLU) vs. 0.12 ± 0.01 (Control), P < 0.01; 5.4 ± 1.0 (HLU) vs. 10.0 ± 1.3 % (Control), P = 0.01, respectively]. Three weeks after releasing from HLU, the SDTC became comparable to the control range. Using a modeling study, the observed differences in the waveforms could be explained by reduced persistent Na(+) currents along with parameters related to current leakage. Quantification of RNA of a SCA1A gene coding a voltage-gated Na(+) channel tended to be decreased in the sciatic nerve in HLU. The present study suggested that axonal ion currents are altered in vivo by HLU. It is still undetermined whether the dysfunctional axonal ion currents have any pathogenicity on neuromuscular atrophy or are the results of neural plasticity by atrophy. PMID:26909041

  15. Same-day physical therapy consults in an outpatient neuromuscular disease physician clinic

    PubMed Central

    Pucillo, Evan M; Christensen-Mayer, Nancy; Poole, Shelly D; Whitten, Denise M; Freeman, Danielle; Bohe, Blake R; Swensen, Brandon R; Smith, A Gordon; Johnson, Nicholas E

    2016-01-01

    Background Team-based care has been shown to offer more comprehensive benefits to patients when compared to standard physician-based care alone in clinics for chronic conditions. However, apart from grant-funded multidisciplinary clinics, there are no reports on the usage of same-day physical therapy (PT) consults within a daily outpatient neuromuscular disease (NMD) physician clinic. Objective To determine the impact of same-day PT consults at the University of Utah’s outpatient Clinical Neurosciences Center. Design A qualitative assessment and survey of patient satisfaction. Methods An eight question Health Insurance Portability and Accountability Act-compliant patient satisfaction survey using a 5-point Likert scale was administered. Demographic data and Press-Ganey Provider Satisfaction surveys were retrospectively collected from electronic medical records for patients receiving same-day PT encounters in the neuromuscular division over 1 year. Results Mean (standard deviation) age was 54.22 (19.81) years for 134 patient encounters, median age was 60 years, with 76 male (57%) and 58 female (43%) patients. Mean Likert score for 61 self-reported patient satisfaction surveys for same-day PT consults was 4.87 (97.4%). Press-Ganey Provider Satisfaction scores improved from 89.9% (N=287) for the year prior to 90.8% (N=320) for the corresponding year (P=0.427). A total of 46 (75.4%) patients have either never before received PT care or never before received PT care for their NMD, 67.4% of whom were male. Conclusion Same-day PT consults in an outpatient NMD physician clinic demonstrated excellent patient satisfaction and improved access to specialty care. This model could potentially be implemented in other academic medical centers to improve access to rehabilitation services for patients with NMD. PMID:27757040

  16. Higher Neuromuscular Manifestations of Fatigue in Dynamic than Isometric Pull-Up Tasks in Rock Climbers

    PubMed Central

    Boccia, Gennaro; Pizzigalli, Luisa; Formicola, Donato; Ivaldi, Marco; Rainoldi, Alberto

    2015-01-01

    Neuromuscular assessment of rock climbers has been mainly focused on forearm muscles in the literature. We aimed to extend the body of knowledge investigating on two other upper limb muscles during sport-specific activities in nine male rock climbers. We assessed neuromuscular manifestations of fatigue recording surface electromyographic signals from brachioradialis and teres major muscles, using multi-channel electrode arrays. Participants performed two tasks until volitional exhaustion: a sequence of dynamic pull-ups and an isometric contraction sustaining the body at half-way of a pull-up (with the elbows flexed at 90°). The tasks were performed in randomized order with 10 minutes of rest in between. The normalized rate of change of muscle fiber conduction velocity was calculated as the index of fatigue. The time-to-task failure was significantly shorter in the dynamic (31 ±10 s) than isometric contraction (59 ±19 s). The rate of decrease of muscle fiber conduction velocity was found steeper in the dynamic than isometric task both in brachioradialis (isometric: −0.2 ±0.1%/s; dynamic: −1.2 ±0.6%/s) and teres major muscles (isometric: −0.4±0.3%/s; dynamic: −1.8±0.7%/s). The main finding was that a sequence of dynamic pull-ups lead to higher fatigue than sustaining the body weight in an isometric condition at half-way of a pull-up. Furthermore, we confirmed the possibility to properly record physiological CV estimates from two muscles, which had never been studied before in rock climbing, in highly dynamic contractions. PMID:26557188

  17. Expanding genotype/phenotype of neuromuscular diseases by comprehensive target capture/NGS

    PubMed Central

    Tian, Xia; Liang, Wen-Chen; Feng, Yanming; Wang, Jing; Zhang, Victor Wei; Chou, Chih-Hung; Huang, Hsien-Da; Lam, Ching Wan; Hsu, Ya-Yun; Lin, Thy-Sheng; Chen, Wan-Tzu

    2015-01-01

    Objective: To establish and evaluate the effectiveness of a comprehensive next-generation sequencing (NGS) approach to simultaneously analyze all genes known to be responsible for the most clinically and genetically heterogeneous neuromuscular diseases (NMDs) involving spinal motoneurons, neuromuscular junctions, nerves, and muscles. Methods: All coding exons and at least 20 bp of flanking intronic sequences of 236 genes causing NMDs were enriched by using SeqCap EZ solution-based capture and enrichment method followed by massively parallel sequencing on Illumina HiSeq2000. Results: The target gene capture/deep sequencing provides an average coverage of ∼1,000× per nucleotide. Thirty-five unrelated NMD families (38 patients) with clinical and/or muscle pathologic diagnoses but without identified causative genetic defects were analyzed. Deleterious mutations were found in 29 families (83%). Definitive causative mutations were identified in 21 families (60%) and likely diagnoses were established in 8 families (23%). Six families were left without diagnosis due to uncertainty in phenotype/genotype correlation and/or unidentified causative genes. Using this comprehensive panel, we not only identified mutations in expected genes but also expanded phenotype/genotype among different subcategories of NMDs. Conclusions: Target gene capture/deep sequencing approach can greatly improve the genetic diagnosis of NMDs. This study demonstrated the power of NGS in confirming and expanding clinical phenotypes/genotypes of the extremely heterogeneous NMDs. Confirmed molecular diagnoses of NMDs can assist in genetic counseling and carrier detection as well as guide therapeutic options for treatable disorders. PMID:27066551

  18. Performance and neuromuscular adaptations following differing ratios of concurrent strength and endurance training.

    PubMed

    Jones, Thomas W; Howatson, Glyn; Russell, Mark; French, Duncan N

    2013-12-01

    The interference effect attenuates strength and hypertrophic responses when strength and endurance training are conducted concurrently; however, the influence of training frequency on these responses remain unclear when varying ratios of concurrent strength and endurance training are performed. Therefore, the purpose of the study was to examine the strength, limb girth, and neuromuscular adaptations to varying ratios of concurrent strength and endurance training. Twenty-four men with >2 years resistance training experience completed 6 weeks of 3 days per week of (a) strength training (ST), (b) concurrent strength and endurance training ratio 3:1 (CT3), (c) concurrent strength and endurance training ratio 1:1 (CT1), or (d) no training (CON) in an isolated limb model. Assessments of maximal voluntary contraction by means of isokinetic dynamometry leg extensions (maximum voluntary suppression [MVC]), limb girth, and neuromuscular responses through electromyography (EMG) were conducted at baseline, mid-intervention, and postintervention. After training, ST and CT3 conditions elicited greater MVC increases than CT1 and CON conditions (p ≤ 0.05). Strength training resulted in significantly greater increases in limb girth than both CT1 and CON conditions (p = 0.05 and 0.004, respectively). The CT3 induced significantly greater limb girth adaptations than CON condition (p = 0.04). No effect of time or intervention was observed for EMG (p > 0.05). In conclusion, greater frequencies of endurance training performed increased the magnitude of the interference response on strength and limb girth responses after 6 weeks of 3 days a week of training. Therefore, the frequency of endurance training should remain low if the primary focus of the training intervention is strength and hypertrophy.

  19. Ethical considerations in the management of individuals with severe neuromuscular disorders.

    PubMed

    Bach, J R; Barnett, V

    1994-04-01

    There have been many recent advances in improving the quality of life and prolonging life for individuals with advanced neuromuscular disease. These include the use of physical medicine techniques to balance extremity muscle strength and improve range of motion and noninvasive techniques to provide inspiratory and expiratory muscle assistance to prolong life without resort to tracheostomy. Such advances help eliminate the "crisis" decision making about "going on a respirator" and sophisticated assistive equipment and robotic aids. Physicians and society in general use quality of life issues inappropriately derived by questioning physically able individuals to justify withholding or implementing life-sustaining therapeutic interventions for these individuals. Informed decisions about ethically and financially complex matters such as long-term ventilator use should be made by examining the life satisfaction of competent individuals who have already chosen these options. The great majority of severely disabled ventilator-assisted individuals with neuromuscular disease are satisfied with their lives despite the inability to achieve many of the "usual" goals associated with quality of life in the physically able population. Their principle life satisfaction derives from social relationships, the reorganization of goals and from their immediate environment. Although the Americans with Disabilities Act is seen as an important step to prevent discrimination against disabled individuals, it does little or nothing for the self-directed disabled individual who is not informed by his/her physicians regarding potentially vital therapeutic options nor does it help those who are warehoused in institutions because of lack of a national personal assistance services policy.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Endurance and neuromuscular changes in world-class level kayakers during a periodized training cycle.

    PubMed

    García-Pallarés, Jesús; Sánchez-Medina, Luis; Carrasco, Luis; Díaz, Arturo; Izquierdo, Mikel

    2009-07-01

    This study was undertaken to analyze changes in selected cardiovascular and neuromuscular variables in a group of elite kayakers across a 12-week periodized cycle of combined strength and endurance training. Eleven world-class level paddlers underwent a battery of tests and were assessed four times during the training cycle (T0, T1, T2, and T3). On each occasion subjects completed an incremental test to exhaustion on the kayak-ergometer to determine maximal oxygen uptake (VO(2max)), second ventilatory threshold (VT2), peak blood lactate, paddling speed at VO(2max) (PS(max)) and at VT2 (PS(VT2)), stroke rate at VO(2max) and at VT2, heart rate at VO(2max) and at VT2. One-repetition maximum (1RM) and mean velocity with 45% 1RM load (V (45%)) were assessed in the bench press (BP) and prone bench pull (PBP) exercises. Anthropometric measurements (skinfold thicknesses and muscle girths) were also obtained. Training volume and exercise intensity were quantified for each of three training phases (P1, P2, and P3). Significant improvements in VO(2max) (9.5%), VO(2) at VT2 (9.4%), PS(max) (6.2%), PS(VT2) (4.4%), 1RM in BP (4.2%) and PBP (5.3%), V (45%) in BP (14.4%) and PBP (10.0%) were observed from T0 to T3. A 12-week periodized strength and endurance program with special emphasis on prioritizing the sequential development of specific physical fitness components in each training phase (i.e. muscle hypertrophy and VT2 in P1, and maximal strength and aerobic power in P2) seems effective for improving both cardiovascular and neuromuscular markers of highly trained top-level athletes.

  1. Generation of Functional Neuromuscular Junctions from Human Pluripotent Stem Cell Lines

    PubMed Central

    Puttonen, Katja A.; Ruponen, Marika; Naumenko, Nikolay; Hovatta, Outi H.; Tavi, Pasi; Koistinaho, Jari

    2015-01-01

    Several neuromuscular diseases involve dysfunction of neuromuscular junctions (NMJs), yet there are no patient-specific human models for electrophysiological characterization of NMJ. We seeded cells of neurally-induced embryoid body-like spheres derived from induced pluripotent stem cell (iPSC) or embryonic stem cell (ESC) lines as monolayers without basic fibroblast factor (bFGF) and observed differentiation of neuronal as well as spontaneously contracting, multinucleated skeletal myotubes. The myotubes showed striation, immunoreactivity for myosin heavy chain, actin bundles typical for myo-oriented cells, and generated spontaneous and evoked action potentials (APs). The myogenic differentiation was associated with expression of MyoD1, myogenin and type I ryanodine receptor. Neurons formed end plate like structures with strong binding of α-bungarotoxin, a marker of nicotinic acetylcholine receptors highly expressed in the postsynaptic membrane of NMJs, and expressed SMI-32, a motoneuron marker, as well as SV2, a marker for synapses. Pharmacological stimulation of cholinergic receptors resulted in strong depolarization of myotube membrane and raised Ca2+ concentration in sarcoplasm, while electrical stimulation evoked Ca2+ transients in myotubes. Stimulation of motoneurons with N-Methyl-D-aspartate resulted in reproducible APs in myotubes and end plates displayed typical mEPPs and tonic activity depolarizing myotubes of about 10 mV. We conclude that simultaneous differentiation of neurons and myotubes from patient-specific iPSCs or ESCs results also in the development of functional NMJs. Our human model of NMJ may serve as an important tool to investigate normal development, mechanisms of diseases and novel drug targets involving NMJ dysfunction and degeneration. PMID:26696831

  2. Combined effect of heat stress, dehydration and exercise on neuromuscular function in humans.

    PubMed

    Ftaiti, F; Grélot, L; Coudreuse, J M; Nicol, C

    2001-01-01

    This study examined the combined effect of exercise induced hyperthermia and dehydration on neuromuscular function in human subjects. Six trained male runners ran for 40 min on a treadmill at 65% of their maximal aerobic velocity while wearing a tracksuit covered with an impermeable jacket and pants to impair the evaporation of sweat. These stressful experimental running conditions led the runners to a physiological status close to exhaustion. On average, the 40 min run ended at a heart rate of 196 (SD 8) beats.min-1, a tympanic temperature of 40 (SD 0.3) degrees C and with a loss of body mass of 2 (SD 0.5)%. Pre- and post-running strength tests included measurements of maximal knee extension and flexion torques in both isometric and isokinetic (at 60 and 240 degrees.s-1) conditions. A 20 s endurance test at 240 degrees.s-1 was also performed. Surface electromyographic (EMG) activity was recorded from six knee extensor and flexor muscles during the entire protocol. The treadmill run led to clear decrements in maximal extension torque and EMG activity both in isometric and at the slowest isokinetic velocity (60 degrees.s-1). However, no differences in these parameters were observed at 240 degrees.s-1. Furthermore, the EMG patterns of the major knee extensor and flexor muscles remained remarkably stable during the treadmill run. These results demonstrate that the exercise-induced hyperthermia and dehydration in the present experiments had only minor effects on the neuromuscular performance. However, it is also suggested that high internal body temperature per se could limit the production of high force levels.

  3. Regulation of quantal transmitter secretion by ATP and protein kinases at developing neuromuscular synapses.

    PubMed

    Fu, W M; Chen, Y H; Lee, K F; Liou, J C

    1997-04-01

    The effects of endogenously released ATP on the maturation of developing neuromuscular synapses were investigated in Xenopus nerve-muscle co-cultures. The potentiating action of ATP (1 mM) on spontaneous acetylcholine release was inhibited by P2-purinoceptor antagonists suramin (0.3 mM) and reactive blue 2 (RB-2, 3 microM) in day 1 cultures. Bath application of suramin (10 microM) or RB-2 in day 1 cultures and prolonged treatment for 2 days dramatically decreased the amplitude of both spontaneous synaptic currents (SSCs) and evoked synaptic currents (ESCs) in the same cultures on day 3. Chronic treatment with 8-cyclopentyltheophylline (4 microM) or 6-cyano-2,3-dihydroxy-7-nitroquinoxaline (CNQX, 10 microM), P1-purinoceptor and glutamate receptor antagonists respectively, did not exert such an inhibitory effect. Chronic treatment with suramin or RB-2 for 2 days had no significant effect on the amplitude of either iontophoretic acetylcholine-induced whole-cell currents or single acetylcholine channel measurements in 3-day-old cultured myocytes. In addition, prolonged treatment for 2 days with various kinase inhibitors such as H-8 (10 microM), KN-62 (5 microM) and H-7 (10 microM) also decreased the amplitudes of both spontaneous and evoked synaptic currents in natural synapses, but not those of iontophoretic acetylcholine-induced currents. Furthermore, suramin and these protein kinase inhibitors also decreased the amplitude of spontaneous synaptic currents in manipulated synapses of 'vacated' nerve terminals. The results suggest that endogenously released ATP, acting in concert with various protein kinases, is involved in the maintenance and/or development of the quantum size of synaptic vesicles at embryonic neuromuscular synapses. PMID:9153574

  4. Assembly, plasticity and selective vulnerability to disease of mouse neuromuscular junctions.

    PubMed

    Santos, Alexandre Ferrão; Caroni, Pico

    2003-01-01

    Although physiological differences among neuromuscular junctions (NMJs) have long been known, NMJs have usually been considered as one type of synapse, restricting their potential value as model systems to investigate mechanisms controlling synapse assembly and plasticity. Here we discuss recent evidence that skeletal muscles in the mouse can be subdivided into two previously unrecognized subtypes, designated FaSyn and DeSyn muscles. These muscles differ in the pattern of neuromuscular synaptogenesis during embryonic development. Differences between classes are intrinsic to the muscles, and manifest in the absence of innervation or agrin. The distinct rates of synaptogenesis in the periphery may influence processes of circuit maturation through retrograde signals. While NMJs on FaSyn and DeSyn muscles exhibit a comparable anatomical organization in postnatal mice, treatments that challenge synaptic stability result in nerve sprouting, NMJ remodeling, and ectopic synaptogenesis selectively on DeSyn muscles. This anatomical plasticity of NMJs diminishes greatly between 2 and 6 months postnatally. NMJs lacking this plasticity are lost selectively and very early on in mouse models of motoneuron disease, suggesting that disease-associated motoneuron dysfunction may fail to initiate maintenance processes at "non-plastic" NMJs. Transgenic mice overexpressing growth-promoting proteins in motoneurons exhibit greatly enhanced stimulus-induced sprouting restricted to DeSyn muscles, supporting the notion that anatomical plasticity at the NMJ is primarily controlled by processes in the postsynaptic muscle. The discovery that entire muscles in the mouse differ substantially in the anatomical plasticity of their synapses establishes NMJs as a uniquely advantageous experimental system to investigate mechanisms controlling synaptic rearrangements at defined synapses in vivo.

  5. Effect of whole body vibration frequency on neuromuscular activity in ACL-deficient and healthy males

    PubMed Central

    Giombini, A; Menotti, F; Piccinini, A; Fagnani, F; Di Cagno, A; Macaluso, A; Pigozzi, F

    2015-01-01

    Whole-body vibration (WBV) has been shown to enhance muscle activity via reflex pathways, thus having the potential to contrast muscle weakness in individuals with rupture of the anterior cruciate ligament (ACL). The present study aimed to compare the magnitude of neuromuscular activation during WBV over a frequency spectrum from 20 to 45 Hz between ACL-deficient and healthy individuals. Fifteen males aged 28±4 with ACL rupture and 15 age-matched healthy males were recruited. Root mean square (RMS) of the surface electromyogram from the vastus lateralis in both limbs was computed during WBV in a static half-squat position at 20, 25, 30, 35, 40 and 45 Hz, and normalized to the RMS while maintaining the half-squat position without vibration. The RMS of the vastus lateralis in the ACL-deficient limb was significantly greater than in the contralateral limb at 25, 30, 35 and 40 Hz (P<0.05) and in both limbs of the healthy participants (dominant limb at 25, 30, 35, 40 and 45 Hz, P<0.05; non dominant limb at 20, 25, 30, 35, 40 and 45 Hz, P<0.05). The greater neuromuscular activity in the injured limb compared to the uninjured limb of the ACL-deficient patients and to both limbs of the healthy participants during WBV might be due to either augmented excitatory or reduced inhibitory neural inflow to motoneurons of the vastus lateralis through the reflex pathways activated by vibratory stimuli. The study provides optimal WBV frequencies which might be used as reference values for ACL-deficient patients. PMID:26424928

  6. Assessment of neuromuscular function after different strength training protocols using tensiomyography.

    PubMed

    de Paula Simola, Rauno Á; Harms, Nico; Raeder, Christian; Kellmann, Michael; Meyer, Tim; Pfeiffer, Mark; Ferrauti, Alexander

    2015-05-01

    The purpose of the study was to analyze tensiomyography (TMG) sensitivity to changes in muscle force and neuromuscular function of the muscle rectus femoris (RF) using TMG muscle properties after 5 different lower-limb strength training protocols (multiple sets; DS = drop sets; eccentric overload; FW = flywheel; PL = plyometrics). After baseline measurements, 14 male strength trained athletes completed 1 squat training protocol per week over a 5-week period in a randomized controlled order. Maximal voluntary isometric contraction (MVIC), TMG measurements of maximal radial displacement of the muscle belly (Dm), contraction time between 10 and 90% of Dm (Tc), and mean muscle contraction velocities from the beginning until 10% (V10) and 90% of Dm (V90) were analyzed up to 0.5 (post-train), 24 (post-24), and 48 hours (post-48) after the training interventions. Significant analysis of variance main effects for measurement points were found for all TMG contractile properties and MVIC (p < 0.01). Dm and V10 post-train values were significantly lower after protocols DS and FW compared with protocol PL (p = 0.032 and 0.012, respectively). Dm, V10, and V90 decrements correlated significantly to the decreases in MVIC (r = 0.64-0.67, p ≤ 0.05). Some TMG muscle properties are sensitive to changes in muscle force, and different lower-limb strength training protocols lead to changes in neuromuscular function of RF. In addition, those protocols involving high and eccentric load and a high total time under tension may induce higher changes in TMG muscle properties. PMID:25474337

  7. Estrogenic support of motoneuron dendritic growth via the neuromuscular periphery in a sexually dimorphic motor system.

    PubMed

    Nowacek, Ari S; Sengelaub, Dale R

    2006-08-01

    The lumbar spinal cord of rats contains the sexually dimorphic, steroid-sensitive spinal nucleus of the bulbocavernosus (SNB). In males, the growth of SNB dendrites is steroid-dependent: dendrites fail to grow after castration, but grow in castrates treated with androgens or estrogens. Blocking estradiol synthesis or estrogen receptors in gonadally intact males attenuates SNB dendritic growth, suggesting that estrogens are required and must be able to act at their receptors to support normal masculine dendritic growth. However, SNB motoneurons do not accumulate estrogens, suggesting that estrogens act indirectly to support SNB dendritic growth. In this experiment, we examined whether local estrogen action in the neuromuscular periphery was involved in the postnatal development of SNB motoneurons. Motoneuron morphology was assessed in gonadally intact and castrated males. Gonadally intact males were left untreated or given either blank or tamoxifen implants sutured to the target musculature, or tamoxifen interscapular implants. Castrated males were left untreated or were given estradiol by muscle or interscapular implants or systemic injection during the period of SNB dendritic growth. At postnatal day 28, when SNB dendritic length is normally maximal, SNB motoneurons were retrogradely labeled with cholera toxin-HRP and reconstructed in three dimensions. While interscapular tamoxifen implants were ineffective, blocking estrogen receptors at the target musculature resulted in attenuation of SNB dendritic growth. In contrast, while interscapular implants of estradiol were ineffective, local treatment with estradiol at the target musculature in castrated males resulted in masculinization of dendritic growth. Thus, estrogens may act by an indirect action in the neuromuscular periphery to support SNB dendritic growth.

  8. A training program to improve neuromuscular and performance indices in female high school basketball players.

    PubMed

    Noyes, Frank R; Barber-Westin, Sue D; Smith, Stephanie T; Campbell, Thomas; Garrison, Tiina T

    2012-03-01

    The purpose of this study was to determine if a sports-specific training program could improve neuromuscular and performance indices in female high school basketball players. We combined components from a published anterior cruciate ligament injury prevention program for jump and strength training with other exercises and drills to improve speed, agility, overall strength, and aerobic conditioning. We hypothesized that this sports-specific training program would lead to significant improvements in neuromuscular and performance indices in high school female basketball players. Fifty-seven female athletes aged 14-17 years participated in the supervised 6-week program, 3 d·wk(-1) for approximately 90-120 minutes per session. The program was conducted on the basketball court and in weight room facilities in high schools. The athletes underwent a video drop-jump test, multistage fitness test, vertical jump test, and an 18-m sprint test before and upon completion of the training program. All the subjects attended at least 14 training sessions. After training, a significant increase was found in the mean estimated VO2max (p < 0.001), with 89% of the athletes improving this score. In the drop-jump video test, significant increases were found in the mean absolute knee separation distance (p < 0.0001) and in the mean normalized knee separation distance (p < 0.0001), indicating a more neutral lower limb alignment on landing. A significant improvement was found in the vertical jump test (p < 0.0001); however, the effect size was small (0.09). No improvement was noted in the sprint test. This program significantly improved lower limb alignment on a drop-jump test and estimated maximal aerobic power and may be implemented preseason or off-season in high school female basketball players. PMID:22289699

  9. Sport-specific functional movement can simulate aspects of neuromuscular fatigue occurring in team sports.

    PubMed

    Wilke, Jan; Fleckenstein, Johannes; Krause, Frieder; Vogt, Lutz; Banzer, Winfried

    2016-06-01

    Fatigue protocols have been used over the years to examine muscular exhaustion. As an alternative to approaches in laboratory settings, functional agility protocols claiming to mimic the multifaceted loads of athletic activity have been proposed. This study aimed to examine the effects of a functional agility short-term fatigue protocol (FAST-FP) on neuromuscular function. Twenty-eight healthy sports students (15 males, aged 24.3 ± 2.4 years) completed the FAST-FP, which consists of four components: three counter-movement jumps (90% of individual maximum), a 20-s bout of step-ups, three bodyweight squats and an agility run. Tasks were repeated until the participants no longer achieved the required jump height in two consecutive sets. Outcomes (pre-post) encompassed subjective exhaustion (visual analogue scale [VAS]), maximum isometric voluntary force of the knee extensors (MIVF), reactive strength index (RSI), mean power frequency (MPF, measured using surface electromyography) and maximum knee range of motion (ROM). Post-intervention, VAS (+54 mm) increased significantly, while MIVF (-6.1%), RSI (-10.7%) and MPF (-4.1%) were reduced (p < 0.05). No changes were observed for ROM (p > 0.05). The FAST-FP induces small-to-moderate impairments in neuromuscular function and considerable self-perceived fatigue. Current evidence on exhaustion developing in team sports suggests that this magnitude of fatigue is similar. The protocol might thus be valuable in the evaluation of treatments counteracting post-match fatigue in team sports.

  10. The effect of a carbohydrate mouth-rinse on neuromuscular fatigue following cycling exercise.

    PubMed

    Jeffers, Robert; Shave, Robert; Ross, Emma; Stevenson, Emma J; Goodall, Stuart

    2015-06-01

    Carbohydrate (CHO) mouth-rinsing, rather than ingestion, is known to improve performance of high-intensity (>75% maximal oxygen uptake) short-duration (≤1 h) cycling exercise. Mechanisms responsible for this improvement, however, are unclear. The present study aimed to investigate the effect of a CHO mouth-rinse on cycling time-trial (TT) performance and mechanisms of fatigue. On 2 separate occasions, 9 male cyclists (mean ± SD; maximal oxygen uptake, 61 ± 5 mL·kg(-1)·min(-1)) completed 45 min at 70% maximum power output (preload) followed by a 15-min TT. At 7.5-min intervals during the preload and TT, participants were given either a tasteless 6.4% maltodextrin mouth-rinse (CHO) or water (placebo (PLA)) in a double-blind, counterbalanced fashion. Isometric knee-extension force and electromyographic responses to percutaneous electrical stimulation and transcranial magnetic stimulation were measured before, after the preload, and after the TT. There were greater decreases in maximal voluntary contraction after the TT in PLA (20% ± 10%) compared with the CHO (12% ± 8%; P = 0.019). Voluntary activation was reduced following exercise in both trials, but did not differ between conditions (PLA -10% ± 8% vs. CHO -5% ± 4%; P = 0.150). The attenuation in the manifestation of global fatigue did not translate into a TT improvement (248 ± 23 vs. 248 ± 39 W for CHO and PLA, respectively). Furthermore, no differences in heart rate or ratings of perceived exertion were found between the 2 conditions. These data suggest that CHO mouth-rinsing attenuates neuromuscular fatigue following endurance cycling. Although these changes did not translate into a performance improvement, further investigation is required into the role of CHO mouth-rinse in alleviating neuromuscular fatigue.

  11. Neuromuscular response of the trunk to sudden gait disturbances: Forward vs. backward perturbation.

    PubMed

    Mueller, Juliane; Engel, Tilman; Mueller, Steffen; Kopinski, Stephan; Baur, Heiner; Mayer, Frank

    2016-10-01

    The study aimed to analyse neuromuscular activity of the trunk comparing four different perturbations during gait. Thirteen subjects (28±3yrs) walked (1m/s) on a split-belt treadmill, while 4 (belt) perturbations (F1, F2, B1, B2) were randomly applied. Perturbations differed, related to treadmill belt translation, in direction (forward (F)/backward (B)) and amplitude (20m/s(2) (1)/40m/s(2) (2)). Trunk muscle activity was assessed with a 12-lead-EMG. EMG-RMS [%] (0-200ms after perturbation; normalized to RMS of normal gait) was analyzed for muscles and four trunk areas (ventral left/right; dorsal left/right). Ratio of ventral:dorsal muscles were calculated. Muscle onset [ms] was determined. Data analysis was conducted descriptively, followed by ANOVA (post hoc Tukey-Kramer (α=0.05)). All perturbations lead to an increase in EMG-RMS (428±289%). F1 showed the lowest and F2 the highest increase for the flexors. B2 showed the highest increase for the extensors. Significant differences between perturbations could be observed for 6 muscles, as well as the 4 trunk areas. Ratio analysis revealed no significant differences (range 1.25 (B1) to 1.71 (F2) between stimuli. Muscle response time (ventral: 87.0±21.7ms; dorsal: 88.4±17.0ms) between stimuli was only significant (p=0.005) for the dorsal muscles. Magnitude significantly influences neuromuscular trunk response patterns in healthy adults. Regardless of direction ventral muscles always revealed higher relative increase of activity while compensating the walking perturbations.

  12. A training program to improve neuromuscular and performance indices in female high school basketball players.

    PubMed

    Noyes, Frank R; Barber-Westin, Sue D; Smith, Stephanie T; Campbell, Thomas; Garrison, Tiina T

    2012-03-01

    The purpose of this study was to determine if a sports-specific training program could improve neuromuscular and performance indices in female high school basketball players. We combined components from a published anterior cruciate ligament injury prevention program for jump and strength training with other exercises and drills to improve speed, agility, overall strength, and aerobic conditioning. We hypothesized that this sports-specific training program would lead to significant improvements in neuromuscular and performance indices in high school female basketball players. Fifty-seven female athletes aged 14-17 years participated in the supervised 6-week program, 3 d·wk(-1) for approximately 90-120 minutes per session. The program was conducted on the basketball court and in weight room facilities in high schools. The athletes underwent a video drop-jump test, multistage fitness test, vertical jump test, and an 18-m sprint test before and upon completion of the training program. All the subjects attended at least 14 training sessions. After training, a significant increase was found in the mean estimated VO2max (p < 0.001), with 89% of the athletes improving this score. In the drop-jump video test, significant increases were found in the mean absolute knee separation distance (p < 0.0001) and in the mean normalized knee separation distance (p < 0.0001), indicating a more neutral lower limb alignment on landing. A significant improvement was found in the vertical jump test (p < 0.0001); however, the effect size was small (0.09). No improvement was noted in the sprint test. This program significantly improved lower limb alignment on a drop-jump test and estimated maximal aerobic power and may be implemented preseason or off-season in high school female basketball players.

  13. Time-dependent neuromuscular parameters in the plantar flexors support greater fatigability of old compared with younger males.

    PubMed

    Wallace, Jonathan W; Power, Geoffrey A; Rice, Charles L; Dalton, Brian H

    2016-02-01

    Older adults are more fatigable than young during dynamic tasks, especially those that involve moderate to fast unconstrained velocity shortening contractions. Rate of torque development (RTD), rate of velocity development (RVD) and rate of neuromuscular activation are time-dependent neuromuscular parameters which have not been explored in relation to age-related differences in fatigability. The purpose was to determine whether these time-dependent measures affect the greater age-related fatigability in peak power during moderately fast and maximal effort shortening plantar flexions. Neuromuscular properties were recorded from 10 old (~ 78 years) and 10 young (~ 24 years) men during 50 maximal-effort unconstrained velocity shortening plantar flexions against a resistance equivalent to 20% maximal voluntary isometric contraction torque. At task termination, peak power, and angular velocity, and torque at peak power were decreased by 30, 18, and 16%, respectively, for the young (p < 0.05), and 46, 28, 30% for the old (p < 0.05) compared to pre-fatigue values with the old exhibiting greater reductions across all measures (p<0.05). Voluntary RVD and RTD decreased, respectively, by 24 and 26% in the young and by 47 and 40% in the old at task termination, with greater decrements in the old (p < 0.05). Rate of neuromuscular activation of the soleus decreased over time for both age groups (~ 47%; p < 0.05), but for the medial gastrocnemius (MG) only the old experienced significant decrements (46%) by task termination. All parameters were correlated strongly with the fatigue-related reduction in peak power (r = 0.81-0.94, p < 0.05), except for MG and soleus rates of neuromuscular activation (r = 0.25-0.30, p > 0.10). Fatigue-related declines in voluntary RTD and RVD were both moderately correlated with MG rate of neuromuscular activation (r = 0.51-0.52, p < 0.05), but exhibited a trend with soleus (r = 0.39-0.41, p = 0.07-0.09). Thus, time-dependent factors, RVD and RTD

  14. Effect of the Masako maneuver and neuromuscular electrical stimulation on the improvement of swallowing function in patients with dysphagia caused by stroke

    PubMed Central

    Byeon, Haewon

    2016-01-01

    [Purpose] The aim of this study was to compare improvements in swallowing function by the intervention of the Masako maneuver and neuromuscular electrical stimulation in patients with dysphagia caused by stroke. [Subjects and Methods] The Masako maneuver (n=23) and neuromuscular electrical stimulation (n=24) were conducted in 47 patients with dysphagia caused by stroke over a period of 4 weeks. Swallowing recovery was recorded using the functional dysphagia scale based on videofluoroscopic studies. [Results] Mean functional dysphagia scale values for the Masako maneuver and neuromuscular electrical stimulation groups decreased after the treatments. However, the pre-post functional dysphagia scale values showed no statistically significant differences between the groups. [Conclusion] The Masako maneuver and neuromuscular electrical stimulation each showed significant effects on the improvement of swallowing function for the patients with dysphagia caused by stroke, but no significant difference was observed between the two treatment methods. PMID:27512266

  15. Rocuronium and sugammadex in a 3 days old neonate for draining an ovarian cyst. Neuromuscular management and review of the literature.

    PubMed

    Carlos, Ricardo Vieira; Torres, Marcelo Luis Abramides; de Boer, Hans D

    2016-01-01

    A case is reported in which a 3-days old neonate with a giant ovarian cyst was scheduled for surgery. The patient received a dose of sugammadex to reverse a rocuronium-induced neuromuscular block. A fast and efficient recovery from neuromuscular block was achieved within 90s. No adverse events or other safety concerns were observed. Furthermore, a review of the literature on the use of sugammadex in neonates was performed.

  16. [Rocuronium and sugammadex in a 3 days old neonate for draining an ovarian cyst. Neuromuscular management and review of the literature].

    PubMed

    Carlos, Ricardo Vieira; Torres, Marcelo Luis Abramides; de Boer, Hans D

    2016-01-01

    A case is reported in which a 3-days old neonate with a giant ovarian cyst was scheduled for surgery. The patient received a dose of sugammadex to reverse a rocuronium-induced neuromuscular block. A fast and efficient recovery from neuromuscular block was achieved within 90s. No adverse events or other safety concerns were observed. Furthermore, a review of the literature on the use of sugammadex in neonates was performed.

  17. The use of “stabilization exercises” to affect neuromuscular control in the lumbopelvic region: a narrative review

    PubMed Central

    Bruno, Paul

    2014-01-01

    It is well-established that the coordination of muscular activity in the lumbopelvic region is vital to the generation of mechanical spinal stability. Several models illustrating mechanisms by which dysfunctional neuromuscular control strategies may serve as a cause and/or effect of low back pain have been described in the literature. The term “core stability” is variously used by clinicians and researchers, and this variety has led to several rehabilitative approaches suggested to affect the neuromuscular control strategies of the lumbopelvic region (e.g. “stabilization exercise”, “motor control exercise”). This narrative review will highlight: 1) the ongoing debate in the clinical and research communities regarding the terms “core stability” and “stabilization exercise”, 2) the importance of sub-grouping in identifying those patients most likely to benefit from such therapeutic interventions, and 3) two protocols that can assist clinicians in this process. PMID:24932016

  18. TREATMENT OF PAIN AND NEUROMUSCULAR TENSION—A Report on Intravenous Use of Tetracaine in 365 Cases

    PubMed Central

    Horan, John S.

    1952-01-01

    Three hundred and sixty-five patients were given tetracaine intravenously for various types of pain and neuromuscular tension. In the treatment of pain, myositis, muscle spasm, and visceral spasm most patients were relieved. Best results were obtained in syndromes in which pain was associated with muscle spasm, such as in pain in the lower part of the back and scalenus anticus syndromes. The effects of tetracaine intravenously are those of analgesia, vasodilatation, and relaxation of spastic muscle. Sixty-five of the patients were treated for neuromuscular tension, and there was good relaxation and increased comfort. Alcoholics were relieved of some of the tension symptoms and may have been helped to resist the desire to drink. Of 14 patients with premenstrual tension, 13 had complete relief. Eight patients with mixed anxiety and tension states also responded well. Toxic and allergic reactions were negligible, and other side effects were infrequent and of no consequence. PMID:12978893

  19. An evidence-based review of hip-focused neuromuscular exercise interventions to address dynamic lower extremity valgus

    PubMed Central

    Ford, Kevin R; Nguyen, Anh-Dung; Dischiavi, Steven L; Hegedus, Eric J; Zuk, Emma F; Taylor, Jeffrey B

    2015-01-01

    Deficits in proximal hip strength or neuromuscular control may lead to dynamic lower extremity valgus. Measures of dynamic lower extremity valgus have been previously shown to relate to increased risk of several knee pathologies, specifically anterior cruciate ligament ruptures and patellofemoral pain. Therefore, hip-focused interventions have gained considerable attention and been successful in addressing these knee pathologies. The purpose of the review was to identify and discuss hip-focused exercise interventions that aim to address dynamic lower extremity valgus. Previous electromyography, kinematics, and kinetics research support the use of targeted hip exercises with non-weight-bearing, controlled weight-bearing, functional exercise, and, to a lesser extent, dynamic exercises in reducing dynamic lower extremity valgus. Further studies should be developed to identify and understand the mechanistic relationship between optimized biomechanics during sports and hip-focused neuromuscular exercise interventions. PMID:26346471

  20. Comparison of the effects of hamstring stretching using proprioceptive neuromuscular facilitation with prior application of cryotherapy or ultrasound therapy.

    PubMed

    Magalhães, Francisco Elezier Xavier; Junior, Arlindo Rodrigues de Mesquita; Meneses, Harnold's Tyson de Sousa; Moreira Dos Santos, Rayele Pricila; Rodrigues, Ezaine Costa; Gouveia, Samara Sousa Vasconcelos; Gouveia, Guilherme Pertinni de Morais; Orsini, Marco; Bastos, Victor Hugo do Vale; Machado, Dionis de Castro Dutra

    2015-05-01

    [Purpose] Stretching using proprioceptive neuromuscular facilitation involve physiological reflex mechanisms through submaximal contraction of agonists which activate Golgi organ, promoting the relaxation reflex. The aim of this study was to evaluate the effects of proprioceptive neuromuscular facilitation alone and with prior application of cryotherapy and thermotherapy on hamstring stretching. [Subjects and Methods] The sample comprised of 32 young subjects with hamstring retraction of the right limb. The subjects were randomly allocated to four groups: the control, flexibility PNF, flexibility PNF associated with cryotherapy, flexibility PNF in association with ultrasound therapy. [Results] After 12 stretching sessions, experimental groups showed significant improvements compared to the control group. Moreover, we did not find any significant differences among the experimental groups indicating PNF stretching alone elicits similar results to PNF stretching with prior administration of cryotherapy or thermotherapy. [Conclusion] PNF without other therapy may be a more practical and less expensive choice for clinical care.

  1. Cyclodextrin-derived host molecules as reversal agents for the neuromuscular blocker rocuronium bromide: synthesis and structure-activity relationships.

    PubMed

    Adam, Julia M; Bennett, D Jonathan; Bom, Anton; Clark, John K; Feilden, Helen; Hutchinson, Edward J; Palin, Ronald; Prosser, Alan; Rees, David C; Rosair, Georgina M; Stevenson, Donald; Tarver, Gary J; Zhang, Ming-Qiang

    2002-04-25

    A series of mono- and per-6-substituted cyclodextrin derivatives were synthesized as synthetic receptors (or host molecules) of rocuronium bromide, the most widely used neuromuscular blocker in anaesthesia. By forming host-guest complexes with rocuronium, these cyclodextrin derivatives reverse the muscle relaxation induced by rocuronium in vitro and in vivo and therefore can be used as reversal agents of the neuromuscular blocker to assist rapid recovery of patients after surgery. Because this supramolecular mechanism of action does not involve direct interaction with the cholinergic system, the reversal by these compounds, e.g., compound 14 (Org 25969), is not accompanied by cardiovascular side effects usually attendant with acetylcholinesterase inhibitors such as neostigmine. The structure-activity relationships are consistent with this supramolecular mechanism of action and are discussed herein. These include the effects of binding cavity size and hydrophobic and electrostatic interaction on the reversal activities of these compounds.

  2. Neuromuscular efficiency of the vastus medialis obliquus and postural balance in professional soccer athletes after anterior cruciate ligament reconstruction.

    PubMed

    Chaves, Shalimá Figueirêdo; Marques, Natália Pereira; Silva, Rômulo Lemos E; Rebouças, Nahra Santos; de Freitas, Luise Monteiro; de Paula Lima, Pedro Olavo; de Oliveira, Rodrigo Ribeiro

    2012-04-01

    The purpose of this study was to evaluate the neuromuscular efficiency of the vastus medialis obliquus and postural balance in high-performance soccer athletes after anterior cruciate ligament (ACL) reconstruction, compared to the uninvolved leg. A cross-sectional study was conducted with 22 male professional soccer players after ACL reconstruction (4-12 months postoperatively). The athletes were submitted to functional rehabilitation with an accelerated protocol on the soccer team. They were evaluated using isokinetic dynamometer, surface electromyography and electronic baropodometer. There was no decrease or difference between neuromuscular efficiency of the VMO when comparing both the limbs after ACL reconstruction in the professional soccer athletes under treatment. The same result was found in postural balance. It can be concluded that the NME of the VMO in the involved member and postural balance were successfully re-established after the reconstruction procedure of the ACL in the sample group studied.

  3. Comparison of the effects of hamstring stretching using proprioceptive neuromuscular facilitation with prior application of cryotherapy or ultrasound therapy

    PubMed Central

    Magalhães, Francisco Elezier Xavier; Junior, Arlindo Rodrigues de Mesquita; Meneses, Harnold’s Tyson de Sousa; Moreira dos Santos, Rayele Pricila; Rodrigues, Ezaine Costa; Gouveia, Samara Sousa Vasconcelos; Gouveia, Guilherme Pertinni de Morais; Orsini, Marco; Bastos, Victor Hugo do Vale; Machado, Dionis de Castro Dutra

    2015-01-01

    [Purpose] Stretching using proprioceptive neuromuscular facilitation involve physiological reflex mechanisms through submaximal contraction of agonists which activate Golgi organ, promoting the relaxation reflex. The aim of this study was to evaluate the effects of proprioceptive neuromuscular facilitation alone and with prior application of cryotherapy and thermotherapy on hamstring stretching. [Subjects and Methods] The sample comprised of 32 young subjects with hamstring retraction of the right limb. The subjects were randomly allocated to four groups: the control, flexibility PNF, flexibility PNF associated with cryotherapy, flexibility PNF in association with ultrasound therapy. [Results] After 12 stretching sessions, experimental groups showed significant improvements compared to the control group. Moreover, we did not find any significant differences among the experimental groups indicating PNF stretching alone elicits similar results to PNF stretching with prior administration of cryotherapy or thermotherapy. [Conclusion] PNF without other therapy may be a more practical and less expensive choice for clinical care. PMID:26157261

  4. Spatial factors and muscle spindle input influence the generation of neuromuscular responses to stimulation of the human foot

    NASA Astrophysics Data System (ADS)

    Layne, Charles S.; Forth, Katharine E.; Abercromby, Andrew F. J.

    2005-05-01

    Removal of the mechanical pressure gradient on the soles leads to physiological adaptations that ultimately result in neuromotor degradation during spaceflight. We propose that mechanical stimulation of the soles serves to partially restore the afference associated with bipedal loading and assists in attenuating the negative neuromotor consequences of spaceflight. A dynamic foot stimulus device was used to stimulate the soles in a variety of conditions with different stimulation locations, stimulation patterns and muscle spindle input. Surface electromyography revealed the lateral side of the sole elicited the greatest neuromuscular response in ankle musculature, followed by the medial side, then the heel. These responses were modified by preceding stimulation. Neuromuscular responses were also influenced by the level of muscle spindle input. These results provide important information that can be used to guide the development of a "passive" countermeasure that relies on sole stimulation and can supplement existing exercise protocols during spaceflight.

  5. Las Campanas Stellar Library

    NASA Astrophysics Data System (ADS)

    Chilingarian, Igor; Zolotukhin, Ivan; Beletsky, Yuri; Worthey, Guy

    2015-08-01

    Stellar libraries are fundamental tools required to understand stellar populations in star clusters and galaxies as well as properties of individual stars. Comprehensive libraries exist in the optical domain, but the near-infrared (NIR) domain stays a couple of decades behind. Here we present the Las Campanas Stellar Library project aiming at obtaining high signal-to-noise intermediate-resolution (R=8000) NIR spectra (0.83<λ<2.5μm) for a sample of 1200 stars in the Southern sky using the Folded-port InfraRed Echelette spectrograph at the 6.5-m Magellan Baade telescope. We developed a dedicated observing strategy and customized the telescope control software in order to achieve the highest possible level of data homogeniety. As of 2015, we observed about 600 stars of all spectral types and luminosity classes making our library the largest homogeneous collection of stellar spectra covering the entire NIR domain. We also re-calibrated in flux and wavelength the two existing optical stellar libraries, INDO-US and UVES-POP and followed up about 400 non-variable stars in the NIR in order to get complete optical-NIR coverage. Worth mentioning that our current sample includes about 80 AGB stars and a few dozens of bulge/LMC/SMC stars.

  6. Presynaptic snake beta-neurotoxins produce tetanic fade and endplate potential run-down during neuromuscular blockade in mouse diaphragm.

    PubMed

    Wilson, H I; Nicholson, G M

    1997-11-01

    The present study investigated the ability of a number of presynaptic snake neurotoxins (snake beta-neurotoxins) to produce nerve-evoked train-of-four fade, tetanic fade and endplate potential run-down during the development of neuromuscular blockade in the isolated mouse phrenic-hemidiaphragm nerve-muscle preparation. All the snake beta-neurotoxins tested, with the exception of notexin, produced train-of-four and tetanic fade of nerve-evoked isometric muscle contractions. Train-of-four fade was not present during the initial depressant or facilitatory phases of muscle tension produced by the snake beta-neurotoxins but developed progressively during the final depressant phase that precedes complete neuromuscular blockade. The 'non-neurotoxic' bovine pancreatic phospholipase A2 and the 'low-toxicity' phospholipase A2 from Naja naja atra venom failed to elicit train-of-four fade, indicating that the phospholipase activity of the snake beta-neurotoxins is not responsible for the development of fade. Intracellular recording of endplate potentials (EPPs) elicited by nerve-evoked trains of stimuli showed a progressive run-down in EPP amplitude during the train following incubation with all snake beta-neurotoxins except notexin. Again this run-down in EPP amplitude was confined to the final depressant phase of snake beta-neurotoxin action. However when EPP amplitude fell to near uniquantal levels (< 3 mV) the extent of toxin induced-fade was reduced. Unlike postjunctional snake alpha-neurotoxins, prejunctional snake beta-neurotoxins interfere with acetylcholine release at the neuromuscular junction during the development of neuromuscular blockade. This study provides further support for the hypothesis that fade in twitch and tetanic muscle tension is due to an underlying rundown in EPP amplitude resulting from a prejunctional alteration of transmitter release rather than a use-dependent block of postjunctional nicotinic receptors.

  7. Effect of 1-year regular Tai Chi on neuromuscular reaction in elderly women: a randomized controlled study.

    PubMed

    Sun, Wei; Zhang, Cui; Song, Qipeng; Li, Weiping; Cong, Yan; Chang, Shuwan; Mao, Dewei; Hong, Youlian

    2016-01-01

    This study assessed the effect of 1-year regular Tai Chi (TC) on neuromuscular reaction in elderly women. A total of 41 elderly women (55 years-68 years) completed the study. The TC group (n = 21) performed the 24-form TC, while the control group (C, n = 20) was instructed to read newspapers or watch television when the TC group practised. Electromyogram measurements were conducted before and after intervention. After a year-long intervention, the post-test results of between-group neuromuscular reaction time showed significant differences in the rectus femoris (t = 3.607, p = 0.001), semitendinosus (t = 2.678, p = 0.011), anterior tibialis (t = 3.455, p = 0.001), and gastrocnemius muscles (t = 4.061, p = 0.000). Within-group results showed that the TC group had significantly shorter neuromuscular reaction time compared to its baseline value in the rectus femoris (t = 3.066, p = 0.006), semitendinosus (t = 2.485, p = 0.022), anterior tibialis (t = 2.311, p = 0.032), and gastrocnemius muscles (t = 2.462, p = 0.023). Results suggested that year-long regular TC can improve neuromuscular reaction function in elderly women.

  8. A Commentary on Real-Time Biofeedback to Augment Neuromuscular Training for ACL Injury Prevention in Adolescent Athletes

    PubMed Central

    Kiefer, Adam W.; Kushner, Adam M.; Groene, John; Williams, Christopher; Riley, Michael A.; Myer, Gregory D.

    2015-01-01

    Anterior cruciate ligament injury and the associated long-term sequelae, such as immediate reductions in physical inactivity, increased adiposity and increased risk of osteoarthritis throughout adulthood, are a major health concern for adolescent athletes. Current interventions for injury prevention may have limited effectiveness, are susceptible to issues of compliance and have not achieved the widespread acceptance necessary to promote full adoption. Neuromuscular training (NMT) is a well-established training intervention introduced to affect change in modifiable biomechanical risk factors to reduce the risk of injury in these athletes. Despite moderate success, neuromuscular training is still limited by its reliance on subjective feedback and after the fact (i.e., offline) objective feedback techniques. The purpose of this commentary is to discuss technological tools that could be used to enhance and objectify targeted biofeedback interventions to complement NMT. Electromyography, force plates, motion sensors, and camera-based motion capture systems are innovative tools that may have realistic feasibility for integration as biofeedback into NMT programs to improve training outcomes. Improved functional deficit identification and corrective analysis may further improve and optimize athletic performance, and decrease the risk of sports-related injury during sport performance. Key points Specific, targeted interventions that isolate injury risk factors and can help correct modifiable neuromuscular deficits are essential. Current training interventions for anterior cruciate ligament (ACL) injury prevention have only demonstrated limited effectiveness and have not achieved the widespread acceptance necessary to promote full adoption to reduce ACL injury rates. The paper provides an overview of innovative strategies and technological tools that could be used to enhance and objectify targeted biofeedback interventions to complement neuromuscular training (NMT

  9. Cryptogenic multifocal ulcerous stenosing enteritis (CMUSE), and neuromuscular and vascular hamartoma (NMVH): two sides of the same coin?

    PubMed

    Setaffy, Lisa; Osuna, María José Martín; Plieschnegger, Wolfgang; del Pino Florez Rial, María; Geboes, Karel; Langner, Cord

    2015-04-01

    Multifocal stenosing enteritis, not related to Crohn's disease or drug intake, has been described under two different terms: "cryptogenic multifocal ulcerous stenosing enteritis" (CMUSE) and "neuromuscular and vascular hamartoma" (NMVH). We present three new cases of this condition and argue that the two terms reflect the same disease entity. Although etiology and pathogenesis of the disease remain largely unclear, obliterative vascular changes may play an important role.

  10. Patient safety in the rehabilitation of children with spinal cord injuries, spina bifida, neuromuscular disorders, and amputations.

    PubMed

    Cancel, David; Capoor, Jaishree

    2012-05-01

    Pediatric patient safety continues to challenge both pediatricians and pediatric physiatrists. While there is a trend toward developing general patient safety initiatives, there is little research on pediatric patient safety. This article identifies major areas of general safety risk, with a focus on timely diagnosis and care coordination to prevent secondary complications that compromise health, function, and quality of life in pediatric neuromuscular disease, spinal cord disorders, and amputation.

  11. Physiological and Neuromuscular Response to a Simulated Sprint-Distance Triathlon: Effect of Age Differences and Ability Level.

    PubMed

    García-Pinillos, Felipe; Cámara-Pérez, José C; González-Fernández, Francisco T; Párraga-Montilla, Juan A; Muñoz-Jiménez, Marcos; Latorre-Román, Pedro Á

    2016-04-01

    This study aimed to describe the acute impact of a simulated sprint-distance triathlon at physiological and neuromuscular levels and to determine whether age and athletic performance influenced the response in triathletes. Nineteen triathletes performed a sprint-distance triathlon under simulated conditions. Cardiovascular response was monitored during the race. Rate of perceived exertion along with muscular performance parameters (countermovement jump [CMJ], squat jump [SJ], and handgrip strength test [HS]) were tested at pre- and posttest and during every transition, while a 20-m sprint test (S20m) was performed before and after the race. Blood lactate was recorded postrace. A repeated measures analysis of variance showed that the neuromuscular response-in terms of CMJ, SJ, and HS-was unchanged (p ≥ 0.05), while S20m performance was impaired at posttest (p < 0.001). A linear regression analysis showed that ΔCMJ predicted the overall race time (R = 0.226; p = 0.046). In addition, 2 cluster analyses (k-means) were performed by grouping according to athletic performance and age. Between-group comparison showed no significant differences in the impact of the race at either the physiological or the neuromuscular level. The results showed that muscular performance parameters were not impaired throughout the race despite high levels of fatigue reported. However, despite maintaining initial levels of muscle force after the race, the fatigue-induced changes in S20m were significant, which could reinforce the need to train sprint ability in endurance athletes. Finally, despite the differences in ability level or in age, the acute physiological and neuromuscular responses to a simulated sprint-distance triathlon were similar.

  12. A Commentary on Real-Time Biofeedback to Augment Neuromuscular Training for ACL Injury Prevention in Adolescent Athletes.

    PubMed

    Kiefer, Adam W; Kushner, Adam M; Groene, John; Williams, Christopher; Riley, Michael A; Myer, Gregory D

    2015-03-01

    Anterior cruciate ligament injury and the associated long-term sequelae, such as immediate reductions in physical inactivity, increased adiposity and increased risk of osteoarthritis throughout adulthood, are a major health concern for adolescent athletes. Current interventions for injury prevention may have limited effectiveness, are susceptible to issues of compliance and have not achieved the widespread acceptance necessary to promote full adoption. Neuromuscular training (NMT) is a well-established training intervention introduced to affect change in modifiable biomechanical risk factors to reduce the risk of injury in these athletes. Despite moderate success, neuromuscular training is still limited by its reliance on subjective feedback and after the fact (i.e., offline) objective feedback techniques. The purpose of this commentary is to discuss technological tools that could be used to enhance and objectify targeted biofeedback interventions to complement NMT. Electromyography, force plates, motion sensors, and camera-based motion capture systems are innovative tools that may have realistic feasibility for integration as biofeedback into NMT programs to improve training outcomes. Improved functional deficit identification and corrective analysis may further improve and optimize athletic performance, and decrease the risk of sports-related injury during sport performance. Key pointsSpecific, targeted interventions that isolate injury risk factors and can help correct modifiable neuromuscular deficits are essential.Current training interventions for anterior cruciate ligament (ACL) injury prevention have only demonstrated limited effectiveness and have not achieved the widespread acceptance necessary to promote full adoption to reduce ACL injury rates.The paper provides an overview of innovative strategies and technological tools that could be used to enhance and objectify targeted biofeedback interventions to complement neuromuscular training (NMT) including

  13. Developing maximal neuromuscular power: part 2 - training considerations for improving maximal power production.

    PubMed

    Cormie, Prue; McGuigan, Michael R; Newton, Robert U

    2011-02-01

    This series of reviews focuses on the most important neuromuscular function in many sport performances: the ability to generate maximal muscular power. Part 1, published in an earlier issue of Sports Medicine, focused on the factors that affect maximal power production while part 2 explores the practical application of these findings by reviewing the scientific literature relevant to the development of training programmes that most effectively enhance maximal power production. The ability to generate maximal power during complex motor skills is of paramount importance to successful athletic performance across many sports. A crucial issue faced by scientists and coaches is the development of effective and efficient training programmes that improve maximal power production in dynamic, multi-joint movements. Such training is referred to as 'power training' for the purposes of this review. Although further research is required in order to gain a deeper understanding of the optimal training techniques for maximizing power in complex, sports-specific movements and the precise mechanisms underlying adaptation, several key conclusions can be drawn from this review. First, a fundamental relationship exists between strength and power, which dictates that an individual cannot possess a high level of power without first being relatively strong. Thus, enhancing and maintaining maximal strength is essential when considering the long-term development of power. Second, consideration of movement pattern, load and velocity specificity is essential when designing power training programmes. Ballistic, plyometric and weightlifting exercises can be used effectively as primary exercises within a power training programme that enhances maximal power. The loads applied to these exercises will depend on the specific requirements of each particular sport and the type of movement being trained. The use of ballistic exercises with loads ranging from 0% to 50% of one-repetition maximum (1RM) and

  14. Static balance and function in children with cerebral palsy submitted to neuromuscular block and neuromuscular electrical stimulation: Study protocol for prospective, randomized, controlled trial

    PubMed Central

    2012-01-01

    Background The use of botulinum toxin A (BT-A) for the treatment of lower limb spasticity is common in children with cerebral palsy (CP). Following the administration of BT-A, physical therapy plays a fundamental role in potentiating the functionality of the child. The balance deficit found in children with CP is mainly caused by muscle imbalance (spastic agonist and weak antagonist). Neuromuscular electrical stimulation (NMES) is a promising therapeutic modality for muscle strengthening in this population. The aim of the present study is to describe a protocol for a study aimed at analyzing the effects of NMES on dorsiflexors combined with physical therapy on static and functional balance in children with CP submitted to BT- A. Methods/Design Protocol for a prospective, randomized, controlled trial with a blinded evaluator. Eligible participants will be children with cerebral palsy (Levels I, II and III of the Gross Motor Function Classification System) between five and 12 years of age, with independent gait with or without a gait-assistance device. All participants will receive BT-A in the lower limbs (triceps surae). The children will then be randomly allocated for either treatment with motor physical therapy combined with NMES on the tibialis anterior or motor physical therapy alone. The participants will be evaluated on three occasions: 1) one week prior to the administration of BT-A; 2) one week after the administration of BT-A; and 3) four months after the administration of BT-A (end of intervention). Spasticity will be assessed by the Modified Ashworth Scale and Modified Tardieu Scale. Static balance will be assessed using the Medicapteurs Fusyo pressure platform and functional balance will be assessed using the Berg Balance Scale. Discussion The aim of this protocol study is to describe the methodology of a randomized, controlled, clinical trial comparing the effect of motor physical therapy combined with NMES on the tibialis anterior muscle or motor

  15. Consensus statement: the use of intravenous immunoglobulin in the treatment of neuromuscular conditions report of the AANEM ad hoc committee.

    PubMed

    Donofrio, Peter D; Berger, Alan; Brannagan, Thomas H; Bromberg, Mark B; Howard, James F; Latov, Normal; Quick, Adam; Tandan, Rup

    2009-11-01

    Intravenous immunoglobulin (IVIG) is a therapeutic biologic agent that has been prescribed for over two decades to treat various neuromuscular conditions. Most of the treatments are given off-label, as little evidence from large randomized trials exists to support its use. Recently, IGIV-C has received an indication for the treatment of chronic inflammatory demyelinating polyneuropathy (CIDP). Because of the lack of evidence, an ad hoc committee of the AANEM was convened to draft a consensus statement on the rational use of IVIG for neuromuscular disorders. Recommendations were categorized as Class I-IV based on the strength of the medical literature. Class I evidence exists to support the prescription of IVIG to treat patients with Guillain-Barré syndrome (GBS), CIDP, multifocal motor neuropathy, refractory exacerbations of myasthenia gravis, Lambert-Eaton syndrome, dermatomyositis, and stiff person syndrome. Treatment of Fisher syndrome, polymyositis, and certain presumed autoimmune neuromuscular disorders is supported only by Class IV studies, whereas there is no convincing data to substantiate the treatment of inclusion body myopathy (IBM), idiopathic neuropathies, brachial plexopathy, or diabetic amyotrophy using IVIG. Treatment with IVIG must be administered in the context of its known adverse effects. There is little evidence to advise the clinician on the proper dosing of IVIG and duration of therapy.

  16. An improved method to determine neuromuscular properties using force laws - From single muscle to applications in human movements.

    PubMed

    Siebert, T; Sust, M; Thaller, S; Tilp, M; Wagner, H

    2007-04-01

    We evaluate an improved method for individually determining neuromuscular properties in vivo. The method is based on Hill's equation used as a force law combined with Newton's equation of motion. To ensure the range of validity of Hill's equation, we first perform detailed investigations on in vitro single muscles. The force-velocity relation determined with the model coincides well with results obtained by standard methods (r=.99) above 20% of the isometric force. In addition, the model-predicted force curves during work loop contractions very well agree with measurements (mean difference: 2-3%). Subsequently, we deduce theoretically under which conditions it is possible to combine several muscles of the human body to model muscles. This leads to a model equation for human leg extension movements containing parameters for the muscle properties and for the activation. To numerically determine these invariant neuromuscular properties we devise an experimental method based on concentric and isometric leg extensions. With this method we determine individual muscle parameters from experiments such that the simulated curves agree well with experiments (r=.99). A reliability test with 12 participants revealed correlations r=.72-.91 for the neuromuscular parameters (p<.01). Predictions of similar movements under different conditions show mean errors of about 5%. In addition, we present applications in sports practise and theory.

  17. Genomic and proteomic profiling reveals reduced mitochondrial function and disruption of the neuromuscular junction driving rat sarcopenia.

    PubMed

    Ibebunjo, Chikwendu; Chick, Joel M; Kendall, Tracee; Eash, John K; Li, Christine; Zhang, Yunyu; Vickers, Chad; Wu, Zhidan; Clarke, Brian A; Shi, Jun; Cruz, Joseph; Fournier, Brigitte; Brachat, Sophie; Gutzwiller, Sabine; Ma, QiCheng; Markovits, Judit; Broome, Michelle; Steinkrauss, Michelle; Skuba, Elizabeth; Galarneau, Jean-Rene; Gygi, Steven P; Glass, David J

    2013-01-01

    Molecular mechanisms underlying sarcopenia, the age-related loss of skeletal muscle mass and function, remain unclear. To identify molecular changes that correlated best with sarcopenia and might contribute to its pathogenesis, we determined global gene expression profiles in muscles of rats aged 6, 12, 18, 21, 24, and 27 months. These rats exhibit sarcopenia beginning at 21 months. Correlation of the gene expression versus muscle mass or age changes, and functional annotation analysis identified gene signatures of sarcopenia distinct from gene signatures of aging. Specifically, mitochondrial energy metabolism (e.g., tricarboxylic acid cycle and oxidative phosphorylation) pathway genes were the most downregulated and most significantly correlated with sarcopenia. Also, perturbed were genes/pathways associated with neuromuscular junction patency (providing molecular evidence of sarcopenia-related functional denervation and neuromuscular junction remodeling), protein degradation, and inflammation. Proteomic analysis of samples at 6, 18, and 27 months confirmed the depletion of mitochondrial energy metabolism proteins and neuromuscular junction proteins. Together, these findings suggest that therapeutic approaches that simultaneously stimulate mitochondrogenesis and reduce muscle proteolysis and inflammation have potential for treating sarcopenia.

  18. Delayed effect of Kinesio Taping on neuromuscular performance, balance, and lower limb function in healthy individuals: a randomized controlled trial

    PubMed Central

    Lins, Caio A. A.; Borges, Daniel T.; Macedo, Liane B.; Costa, Karinna S. A.; Brasileiro, Jamilson S.

    2016-01-01

    ABSTRACT Background Kinesio Taping (KT) is an elastic bandage that aims to improve neuromuscular performance, although there is no consensus as to its benefits. Objective To analyze the immediate and delayed effects of KT on the neuromuscular performance of the femoral quadriceps, on balance, and lower limb function in healthy subjects. Method This is a randomized controlled trial. Thirty-six women with a mean age of 22.2±3.6 years and BMI of 22.5±2.3 Kg/m2 were divided into three groups: control, with ten minutes of rest (control, n=12), application of Kinesio Taping without tension (placebo, n=12) and with tension (KT, n=12) on the quadriceps. The primary outcome was isokinetic performance, while secondary outcomes were the single-hop test, one-footed static balance, and electromyographic activity. The evaluations were carried out in five stages: 1) before application of KT, 2) immediately after the application of KT, 3) after 24h, 4) after 48h, and 5) after 72h. Mixed ANOVA was used to determine differences between groups. Results There was no change in one-footed static balance, electromyographic activity of the VL in the lower limb function, nor in isokinetic performance between groups. Conclusion KT promotes neither immediate nor delayed changes in neuromuscular performance of the femoral quadriceps in healthy women. PMID:27437714

  19. Single-Channel EMG Classification With Ensemble-Empirical-Mode-Decomposition-Based ICA for Diagnosing Neuromuscular Disorders.

    PubMed

    Naik, Ganesh R; Selvan, S Easter; Nguyen, Hung T

    2016-07-01

    An accurate and computationally efficient quantitative analysis of electromyography (EMG) signals plays an inevitable role in the diagnosis of neuromuscular disorders, prosthesis, and several related applications. Since it is often the case that the measured signals are the mixtures of electric potentials that emanate from surrounding muscles (sources), many EMG signal processing approaches rely on linear source separation techniques such as the independent component analysis (ICA). Nevertheless, naive implementations of ICA algorithms do not comply with the task of extracting the underlying sources from a single-channel EMG measurement. In this respect, the present work focuses on a classification method for neuromuscular disorders that deals with the data recorded using a single-channel EMG sensor. The ensemble empirical mode decomposition algorithm decomposes the single-channel EMG signal into a set of noise-canceled intrinsic mode functions, which in turn are separated by the FastICA algorithm. A reduced set of five time domain features extracted from the separated components are classified using the linear discriminant analysis, and the classification results are fine-tuned with a majority voting scheme. The performance of the proposed method has been validated with a clinical EMG database, which reports a higher classification accuracy (98%). The outcome of this study encourages possible extension of this approach to real settings to assist the clinicians in making correct diagnosis of neuromuscular disorders. PMID:26173218

  20. ACL reconstructed patients with a BPTB graft present an impaired vastus lateralis neuromuscular response during high intensity running.

    PubMed

    Patras, Kostas; Ziogas, Giorgos; Ristanis, Stavros; Tsepis, Elias; Stergiou, Nicholas; Georgoulis, Anastasios D

    2010-11-01

    The purpose of the present study was to investigate whether the electromyographic response of the vastus lateralis (VL) muscle in the anterior cruciate ligament (ACL) reconstructed leg is similar to that of the intact contralateral leg and healthy controls, during moderate and high intensity running. Fourteen bone-patellar tendon-bone (BPTB) ACL reconstructed amateur soccer players and fourteen healthy control amateur soccer players volunteered to participate in the study. Electromyographic (EMG) traces from the vastus lateralis (VL) muscle were collected bilaterally, as athletes ran on a treadmill for 10 min on separate occasions, at moderate and high intensity. The dependent variable examined was the EMG amplitude during stance. During the moderate intensity running, EMG amplitude of the VL did not increase with time for any of the tested legs. During the high intensity running, the EMG amplitude of the VL increased significantly with time for the intact (F=6.747, p=0.001) and the control leg (F=4.258, p=0.008), but remained unchanged for the ACL reconstructed leg. During moderate intensity running, there was no difference in the neuromuscular response of the VL in the reconstructed leg compared to the intact and control leg. High intensity running resulted in an impaired neuromuscular response of the VL in the reconstructed leg compared to the intact and control leg. It seems that potential impairments of the neuromuscular response after ACL reconstruction should be tested under high rather than moderate intensity efforts.