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Critical Care (London, England) Apr 2016Respiratory muscle dysfunction may develop rapidly in critically ill ventilated patients and is associated with increased morbidity, length of intensive care unit stay,... (Review)
Review
Respiratory muscle dysfunction may develop rapidly in critically ill ventilated patients and is associated with increased morbidity, length of intensive care unit stay, costs, and mortality. This review briefly discusses the pathophysiology of respiratory muscle dysfunction in intensive care unit patients and then focuses on strategies that prevent the development of muscle weakness or, if weakness has developed, how respiratory muscle function may be improved. We propose a simple strategy for how these can be implemented in clinical care.
Topics: Critical Illness; Evidence-Based Medicine; Humans; Intensive Care Units; Muscle Weakness; Respiration, Artificial; Respiratory Muscles; Risk Factors; Time Factors; Treatment Outcome
PubMed: 27091359
DOI: 10.1186/s13054-016-1280-y -
Journal of Bone and Mineral Research :... Apr 2017Osteoporotic fracture increases the risk of premature mortality. Muscle weakness is associated with both increased fracture risk and low bone mineral density (BMD).... (Clinical Trial)
Clinical Trial
Osteoporotic fracture increases the risk of premature mortality. Muscle weakness is associated with both increased fracture risk and low bone mineral density (BMD). However, the role of muscle strength in post-fracture mortality is not well understood. This study examines the change of muscle strength measured at quadriceps (QS) before and after fracture and defines the relationship between muscle strength and post-fracture mortality. The study involved 889 women and 295 men (who were participating in the Dubbo Osteoporosis Study) who had at least one low-trauma fracture (ascertained from X-ray reports) after the age of 50 years. Median follow-up time was 11 years (range 1 to 24). To determine the change in muscle strength before and after a fracture, we selected a subset of 344 women and 99 men who had had at least two muscle strength measurements before the fracture event and a subset of 407 women and 105 men who had had at least two measurements after the fracture. During the follow-up period, 366 (41.2%) women and 150 (50.9%) men died. The annual rate of decrease in height-adjusted muscle strength before fracture was 0.27 kg/m (1.85%) in women and 0.40 kg/m (1.79%) in men. Strength loss after fracture was not significantly different from that before fracture. In women, after adjusting for baseline age and BMD, each SD (5 kg/m) lower height-adjusted pre- and post-fracture quadriceps strength was associated with a 27% (hazard ratio [HR] = 1.27; 95% confidence interval [CI] 1.07, 1.50) and 18% (HR = 1.18; 95% CI 1.01, 1.38) increase in post-fracture mortality risk, respectively. Similarly, in men, each SD (5 kg/m) lower height-adjusted pre- and post-fracture QS was associated with increased mortality before fracture (HR = 1.33; 95% CI 1.09, 1.63) and after fracture (HR = 1.43; 95% CI 1.16, 1.78). Muscle weakness accounted for 15% (95% CI 0.05, 0.24) of premature deaths after fracture in women and 23% (95% CI 0.11, 0.35) in men. These results indicate that in the older individuals, lower muscle strength is an independent risk factor for post-fracture mortality. © 2017 American Society for Bone and Mineral Research.
Topics: Age Factors; Aged; Aged, 80 and over; Female; Follow-Up Studies; Fractures, Bone; Humans; Male; Middle Aged; Muscle Strength; Muscle Weakness; Prospective Studies; Sex Factors
PubMed: 27862286
DOI: 10.1002/jbmr.3037 -
Pancreas Sep 2018Pancreatic cancer is the third leading cause of cancer death in the United States, with projections that it will become the second leading cause by the year 2030. It... (Review)
Review
Pancreatic cancer is the third leading cause of cancer death in the United States, with projections that it will become the second leading cause by the year 2030. It carries a dismal prognosis with a 5-year overall survival rate of less than 9% and is associated with numerous comorbidities, the most notable being cachexia. Defined as the loss of muscle mass not reversible by conventional nutritional support, cachexia is seen in over 85% of pancreatic cancer patients and contributes significantly to mortality, where nearly 30% of pancreatic cancer deaths are due to cachexia rather than tumor burden. Therefore, there is an urgent need to identify the mechanisms behind the development of muscle wasting in pancreatic cancer patients and design novel therapeutics targeting cachexia. This review highlights the current understanding surrounding the mechanisms underpinning the development of cachexia in pancreatic cancer, as well as the current mouse models of pancreatic cancer-induced muscle wasting described in the literature.
Topics: Animals; Cachexia; Cytokines; Disease Models, Animal; Humans; Mice; Muscle Weakness; Pancreatic Neoplasms; Prognosis; Signal Transduction; Tumor Burden
PubMed: 30113428
DOI: 10.1097/MPA.0000000000001124 -
The Israel Medical Association Journal... Aug 2021Cervical spinal surgery is considered safe and effective. One of the few specific complications of this procedure is C5 nerve root palsy. Expressed primarily by deltoid...
BACKGROUND
Cervical spinal surgery is considered safe and effective. One of the few specific complications of this procedure is C5 nerve root palsy. Expressed primarily by deltoid muscle and biceps brachii weakness, it is rare and has been related to nerve root traction or to ischemic spinal cord damage.
OBJECTIVES
To determine the clinical and epidemiological traits of C5 palsy. To determine whether C5 palsy occurs predominantly in one specific surgical approach compared to others.
METHODS
A retrospective study of patients who underwent cervical spine surgery at our medical center during a consecutive 8-year period was conducted. The patient data were analyzed for demographics, diagnosis, and surgery type and approach, as well as for complications, with emphasis on the C5 nerve root palsy.
RESULTS
The study group was comprised of 124 patients. Seven (5.6%) developed a C5 palsy following surgery. Interventions were either by anterior, by posterior or by a combined approach. Seven patients developed this complication. All of whom had myelopathy and were older males. A combined anteroposterior (5 patients) and posterior access (2 patients) were the only approaches that were associated with the C5 palsy. None of the patients who were operated via an anterior approach did develop this sequel.
CONCLUSIONS
The incidence of the C5 root palsy in our cohort reached 5.6%. Interventions performed through a combined anterior-posterior access in older myelopathic males, may carry the highest risk for this complication.
Topics: Cervical Plexus; Cervical Vertebrae; Decompression, Surgical; Deltoid Muscle; Female; Humans; Intraoperative Complications; Israel; Male; Middle Aged; Muscle Weakness; Outcome and Process Assessment, Health Care; Paresis; Postoperative Complications; Retrospective Studies; Risk Assessment; Spinal Cord Ischemia
PubMed: 34392627
DOI: No ID Found -
Developmental Medicine and Child... May 2009Impaired airway clearance leads to recurrent chest infections and respiratory deterioration in neuromuscular weakness. It is frequently the cause of death. Cough is the... (Review)
Review
Impaired airway clearance leads to recurrent chest infections and respiratory deterioration in neuromuscular weakness. It is frequently the cause of death. Cough is the major mechanism of airway clearance. Cough has several components, and assessment tools are available to measure the different components of cough. These include measuring peak cough flow, respiratory muscle strength, and inspiratory capacity. Each is useful in assessing the ability to generate an effective cough, and can be used to guide when techniques of assisting airway clearance may be effective for the individual and which are most effective. Techniques to assist airway clearance include augmenting inspiration by air stacking, augmenting expiration by assisting the cough, and augmenting both inspiration and expiration with the mechanical insufflator-exsufflator or by direct suctioning via a tracheostomy. Physiotherapists are invaluable in assisting airway clearance, and in teaching patients and their families how to use these techniques. Use of the mechanical insufflator-exsufflator has gained popularity in recent times, but several simpler, more economical methods are available to assist airway clearance that can be used effectively alone or in combination. This review examines the literature available on the assessment and management of impaired airway clearance in neuromuscular weakness.
Topics: Cough; Exhalation; Humans; Inhalation; Inspiratory Capacity; Muscle Weakness; Pulmonary Ventilation; Respiration, Artificial; Respiratory Muscles; Suction; Tracheostomy
PubMed: 19379290
DOI: 10.1111/j.1469-8749.2008.03260.x -
Acta Neuropathologica Jan 2013Mutations in the skeletal muscle α-actin gene (ACTA1) cause a range of congenital myopathies characterised by muscle weakness and specific skeletal muscle structural... (Review)
Review
Mutations in the skeletal muscle α-actin gene (ACTA1) cause a range of congenital myopathies characterised by muscle weakness and specific skeletal muscle structural lesions. Actin accumulations, nemaline and intranuclear bodies, fibre-type disproportion, cores, caps, dystrophic features and zebra bodies have all been seen in biopsies from patients with ACTA1 disease, with patients frequently presenting with multiple pathologies. Therefore increasingly it is considered that these entities may represent a continuum of structural abnormalities arising due to ACTA1 mutations. Recently an ACTA1 mutation has also been associated with a hypertonic clinical presentation with nemaline bodies. Whilst multiple genes are known to cause many of the pathologies associated with ACTA1 mutations, to date actin aggregates, intranuclear rods and zebra bodies have solely been attributed to ACTA1 mutations. Approximately 200 different ACTA1 mutations have been identified, with 90 % resulting in dominant disease and 10 % resulting in recessive disease. Despite extensive research into normal actin function and the functional consequences of ACTA1 mutations in cell culture, animal models and patient tissue, the mechanisms underlying muscle weakness and the formation of structural lesions remains largely unknown. Whilst precise mechanisms are being grappled with, headway is being made in terms of developing therapeutics for ACTA1 disease, with gene therapy (specifically reducing the proportion of mutant skeletal muscle α-actin protein) and pharmacological agents showing promising results in animal models and patient muscle. The use of small molecules to sensitise the contractile apparatus to Ca(2+) is a promising therapeutic for patients with various neuromuscular disorders, including ACTA1 disease.
Topics: Actins; Animals; Humans; Muscle Contraction; Muscle Weakness; Mutation; Myopathies, Nemaline; Phenotype
PubMed: 22825594
DOI: 10.1007/s00401-012-1019-z -
Developmental Medicine and Child... Sep 2010This systematic review and critical evaluation of the literature was conducted to determine how gross muscle morphology and structure are altered in individuals with... (Review)
Review
AIM
This systematic review and critical evaluation of the literature was conducted to determine how gross muscle morphology and structure are altered in individuals with spastic cerebral palsy (CP).
METHOD
Electronic databases were searched for articles describing studies of muscle morphological and structural properties in individuals with spastic CP. Data describing muscle fascicle length, belly length, fascicle angle, cross-sectional area, volume, and thickness were extracted and effect sizes were computed for comparisons between individuals with spastic CP and typically developed individuals, between the paretic and non-paretic side in individuals with hemiplegia for all muscles examined, and across the full spectrum of gross motor function in individuals with spastic CP.
RESULTS
The final yield consisted of 15 articles that met the inclusion criteria. The main finding of the review was the consistent evidence for reduced muscle belly length, muscle volume, cross-sectional area, and muscle thickness in the comparisons between paretic and typically developed muscle and the paretic and non-paretic muscle across a range of muscles.
INTERPRETATION
Given the importance of muscle morphology and structure for generating muscle force, it is likely that the observed alterations that occur secondary to the neural lesion in individuals with spastic CP contribute to muscle weakness and the attendant loss of motor function in spastic CP.
Topics: Cerebral Palsy; Humans; Muscle, Skeletal; Organ Size; Paresis
PubMed: 20477832
DOI: 10.1111/j.1469-8749.2010.03686.x -
Alimentary Pharmacology & Therapeutics Feb 2010The inflammatory myopathies are a group of acquired diseases characterized by a proximal myopathy caused by an inflammatory infiltrate of the skeletal muscle. The three... (Review)
Review
BACKGROUND
The inflammatory myopathies are a group of acquired diseases characterized by a proximal myopathy caused by an inflammatory infiltrate of the skeletal muscle. The three major diseases are dermatomyositis, polymyositis and inclusion body myositis.
AIMS
To review the gastrointestinal manifestations of myositis.
METHODS
Over 110 articles in the English literature were reviewed.
RESULTS
Dysphagia to solids and liquids occurs in patients with myositis. The pharyngo-oesophageal muscle tone is lost and therefore patients develop nasal speech, hoarseness, nasal regurgitation and aspiration pneumonia. There is tongue weakness, flaccid vocal cords, poor palatal motion and pooling of secretions in the distended hypopharynx. Proximal oesophageal skeletal muscle dysfunction is demonstrated by manometry with low amplitude/absent pharyngeal contractions and decreased upper oesophageal sphincter pressures. Patients exhibit markedly elevated creatine kinase and lactate dehydrogenase levels consistent with muscle injury. Myositis can be associated with inflammatory bowel disease, coeliac disease and interferon treatment of hepatitis C. Corticosteroids and other immunosuppressive drugs comprise the mainstay of treatment. Inclusion body myositis responds poorly to these agents and therefore a myotomy is usually indicated.
CONCLUSION
Myositis mainly involves the skeletal muscles in the upper oesophagus with dysphagia, along with proximal muscle weakness.
Topics: Gastrointestinal Diseases; Humans; Muscle Weakness; Muscle, Skeletal; Myositis; Practice Patterns, Physicians'; Prognosis
PubMed: 19886949
DOI: 10.1111/j.1365-2036.2009.04190.x -
Respiratory Physiology & Neurobiology Nov 2013Most patients are easily liberated from mechanical ventilation (MV) following resolution of respiratory failure and a successful trial of spontaneous breathing, but... (Review)
Review
Most patients are easily liberated from mechanical ventilation (MV) following resolution of respiratory failure and a successful trial of spontaneous breathing, but about 25% of patients experience difficult weaning. MV use leads to cellular changes and weakness, which has been linked to weaning difficulties and has been labeled ventilator induced diaphragm dysfunction (VIDD). Aggravating factors in human studies with prolonged weaning include malnutrition, chronic electrolyte abnormalities, hyperglycemia, excessive resistive and elastic loads, corticosteroids, muscle relaxant exposure, sepsis and compromised cardiac function. Numerous animal studies have investigated the effects of MV on diaphragm function. Virtually all these studies have concluded that MV use rapidly leads to VIDD and have identified cellular and molecular mechanisms of VIDD. Molecular and functional studies on the effects of MV on the human diaphragm have largely confirmed the animal results and identified potential treatment strategies. Only recently potential VIDD treatments have been tested in humans, including pharmacologic interventions and diaphragm "training". A limited number of human studies have found that specific diaphragm training can increase respiratory muscle strength in FTW patients and facilitate weaning, but larger, multicenter trials are needed.
Topics: Animals; Diaphragm; Humans; Muscle Strength; Muscle Weakness; Respiration, Artificial; Respiratory Muscles; Ventilator Weaning
PubMed: 23692928
DOI: 10.1016/j.resp.2013.05.012 -
Neural Plasticity 2021This study presents single-fiber electromyography (EMG) analysis for assessment of paretic muscle changes after stroke. Single-fiber action potentials (SFAPs) were...
This study presents single-fiber electromyography (EMG) analysis for assessment of paretic muscle changes after stroke. Single-fiber action potentials (SFAPs) were recorded from the first dorsal interosseous (FDI) muscle bilaterally in 12 individuals with hemiparetic stroke. The SFAP parameters, including the negative peak duration and the peak-peak amplitude, were measured and further used to estimate muscle fiber diameter through a model based on the quadratic function. The SFAP parameters, fiber density, and muscle fiber diameter derived from the model were compared between the paretic and contralateral muscles. The results show that SFAPs recorded from the paretic muscle had significantly smaller negative peak duration than that from the contralateral muscle. As a result, the derived muscle fiber diameter of the paretic muscle was significantly smaller than that of the contralateral muscle. The fiber density of the paretic muscle was significantly higher than that of the contralateral muscle. These results provide further evidence of remodeled motor units after stroke and suggest that paretic muscle weakness can be due to both complex central and peripheral neuromuscular alterations.
Topics: Action Potentials; Aged; Electromyography; Female; Humans; Male; Middle Aged; Muscle Fibers, Skeletal; Muscle, Skeletal; Paresis; Stroke
PubMed: 34434227
DOI: 10.1155/2021/3045990