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American Family Physician Jan 2020Although the prevalence of muscle weakness in the general population is uncertain, it occurs in about 5% of U.S. adults 60 years and older. Determining the cause of... (Review)
Review
Although the prevalence of muscle weakness in the general population is uncertain, it occurs in about 5% of U.S. adults 60 years and older. Determining the cause of muscle weakness can be challenging. True muscle weakness must first be differentiated from subjective fatigue or pain-related motor impairment with normal motor strength. Muscle weakness should then be graded objectively using a formal tool such as the Medical Research Council Manual Muscle Testing scale. The differential diagnosis of true muscle weakness is extensive, including neurologic, rheumatologic, endocrine, genetic, medication- or toxin-related, and infectious etiologies. A stepwise approach to narrowing this differential diagnosis relies on the history and physical examination combined with knowledge of the potential etiologies. Frailty and sarcopenia are clinical syndromes occurring in older people that can present with generalized weakness. Asymmetric weakness is more common in neurologic conditions, whereas pain is more common in neuropathies or radiculopathies. Identifying abnormal findings, such as Chvostek sign, Babinski reflex, hoarse voice, and muscle atrophy, will narrow the possible diagnoses. Laboratory testing, including electrolyte, thyroid-stimulating hormone, and creatine kinase measurements, may also be helpful. Magnetic resonance imaging is indicated if there is concern for acute neurologic conditions, such as stroke or cauda equina syndrome, and may also guide muscle biopsy. Electromyography is indicated when certain diagnoses are being considered, such as amyotrophic lateral sclerosis, myasthenia gravis, neuropathy, and radiculopathy, and may also guide biopsy. If the etiology remains unclear, specialist consultation or muscle biopsy may be necessary to reach a diagnosis.
Topics: Adult; Aged; Aged, 80 and over; Diagnosis, Differential; Humans; Muscle Weakness; Muscles; Muscular Diseases; Neurologic Examination; Neurology
PubMed: 31939642
DOI: No ID Found -
Critical Care (London, England) Jan 2023Patients with critical illness can lose more than 15% of muscle mass in one week, and this can have long-term detrimental effects. However, there is currently no... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Patients with critical illness can lose more than 15% of muscle mass in one week, and this can have long-term detrimental effects. However, there is currently no synthesis of the data of intensive care unit (ICU) muscle wasting studies, so the true mean rate of muscle loss across all studies is unknown. The aim of this project was therefore to systematically synthetise data on the rate of muscle loss and to identify the methods used to measure muscle size and to synthetise data on the prevalence of ICU-acquired weakness in critically ill patients.
METHODS
We conducted a systematic literature search of MEDLINE, PubMed, AMED, BNI, CINAHL, and EMCARE until January 2022 (International Prospective Register of Systematic Reviews [PROSPERO] registration: CRD420222989540. We included studies with at least 20 adult critically ill patients where the investigators measured a muscle mass-related variable at two time points during the ICU stay. We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and assessed the study quality using the Newcastle-Ottawa Scale.
RESULTS
Fifty-two studies that included 3251 patients fulfilled the selection criteria. These studies investigated the rate of muscle wasting in 1773 (55%) patients and assessed ICU-acquired muscle weakness in 1478 (45%) patients. The methods used to assess muscle mass were ultrasound in 85% (n = 28/33) of the studies and computed tomography in the rest 15% (n = 5/33). During the first week of critical illness, patients lost every day -1.75% (95% CI -2.05, -1.45) of their rectus femoris thickness or -2.10% (95% CI -3.17, -1.02) of rectus femoris cross-sectional area. The overall prevalence of ICU-acquired weakness was 48% (95% CI 39%, 56%).
CONCLUSION
On average, critically ill patients lose nearly 2% of skeletal muscle per day during the first week of ICU admission.
Topics: Adult; Humans; Critical Illness; Intensive Care Units; Muscular Atrophy; Muscle, Skeletal; Muscle Weakness
PubMed: 36597123
DOI: 10.1186/s13054-022-04253-0 -
Critical Care (London, England) Aug 2015A substantial number of patients admitted to the ICU because of an acute illness, complicated surgery, severe trauma, or burn injury will develop a de novo form of... (Review)
Review
A substantial number of patients admitted to the ICU because of an acute illness, complicated surgery, severe trauma, or burn injury will develop a de novo form of muscle weakness during the ICU stay that is referred to as "intensive care unit acquired weakness" (ICUAW). This ICUAW evoked by critical illness can be due to axonal neuropathy, primary myopathy, or both. Underlying pathophysiological mechanisms comprise microvascular, electrical, metabolic, and bioenergetic alterations, interacting in a complex way and culminating in loss of muscle strength and/or muscle atrophy. ICUAW is typically symmetrical and affects predominantly proximal limb muscles and respiratory muscles, whereas facial and ocular muscles are often spared. The main risk factors for ICUAW include high severity of illness upon admission, sepsis, multiple organ failure, prolonged immobilization, and hyperglycemia, and also older patients have a higher risk. The role of corticosteroids and neuromuscular blocking agents remains unclear. ICUAW is diagnosed in awake and cooperative patients by bedside manual testing of muscle strength and the severity is scored by the Medical Research Council sum score. In cases of atypical clinical presentation or evolution, additional electrophysiological testing may be required for differential diagnosis. The cornerstones of prevention are aggressive treatment of sepsis, early mobilization, preventing hyperglycemia with insulin, and avoiding the use parenteral nutrition during the first week of critical illness. Weak patients clearly have worse acute outcomes and consume more healthcare resources. Recovery usually occurs within weeks or months, although it may be incomplete with weakness persisting up to 2 years after ICU discharge. Prognosis appears compromised when the cause of ICUAW involves critical illness polyneuropathy, whereas isolated critical illness myopathy may have a better prognosis. In addition, ICUAW has shown to contribute to the risk of 1-year mortality. Future research should focus on new preventive and/or therapeutic strategies for this detrimental complication of critical illness and on clarifying how ICUAW contributes to poor longer-term prognosis.
Topics: Action Potentials; Autonomic Nervous System Diseases; Autophagy; Biomarkers; Blood Glucose; Critical Illness; Electromyography; Hospital Mortality; Humans; Immobilization; Incidence; Intensive Care Units; Length of Stay; Muscle Strength; Muscle Weakness; Physical Therapy Modalities; Respiration, Artificial; Risk Factors; Sepsis
PubMed: 26242743
DOI: 10.1186/s13054-015-0993-7 -
Annals of Physical and Rehabilitation... Apr 2016Muscle weakness is a common consequence of stroke and can result in a decrease in physical activity. Changes in gait performance can be observed, especially a reduction... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Muscle weakness is a common consequence of stroke and can result in a decrease in physical activity. Changes in gait performance can be observed, especially a reduction in gait speed, and increased gait asymmetry, and energy cost is also reported.
OBJECTIVE
The aim was to determine whether strengthening of the lower limbs can improve strength, balance and walking abilities in patients with chronic stroke.
METHOD
Five databases (Pubmed, Cinhal, Cochrane, Web of Science, Embase) were searched to identify eligible studies. Randomized controlled trials were included and the risk of bias was evaluated for each study. Pooled standardized mean differences were calculated using a random effects model. The PRISMA statement was followed to increase clarity of reporting.
RESULTS
Ten studies, including 355 patients, reporting on the subject of progressive resistance training, specific task training, functional electrical stimulation and aerobic cycling at high-intensity were analysed. These interventions showed a statistically significant effect on strength and the Timed Up-and-Go test, and a non-significant effect on walking and the Berg Balance Scale.
CONCLUSION
Progressive resistance training seemed to be the most effective treatment to improve strength. When it is appropriately targeted, it significantly improves strength.
Topics: Humans; Lower Extremity; Muscle Strength; Muscle, Skeletal; Paresis; Postural Balance; Resistance Training; Stroke; Stroke Rehabilitation; Walking
PubMed: 26969343
DOI: 10.1016/j.rehab.2016.02.001 -
BMC Neurology Sep 2017Multiple sclerosis (MS) can result in significant mental and physical symptoms, specially muscle weakness, abnormal walking mechanics, balance problems, spasticity,... (Review)
Review
BACKGROUND
Multiple sclerosis (MS) can result in significant mental and physical symptoms, specially muscle weakness, abnormal walking mechanics, balance problems, spasticity, fatigue, cognitive impairment and depression. Patients with MS frequently decrease physical activity due to the fear from worsening the symptoms and this can result in reconditioning. Physicians now believe that regular exercise training is a potential solution for limiting the reconditioning process and achieving an optimal level of patient activities, functions and many physical and mental symptoms without any concern about triggering the onset or exacerbation of disease symptoms or relapse.
MAIN BODY
Appropriate exercise can cause noteworthy and important improvements in different areas of cardio respiratory fitness (Aerobic fitness), muscle strength, flexibility, balance, fatigue, cognition, quality of life and respiratory function in MS patients. Aerobic exercise training with low to moderate intensity can result in the improvement of aerobic fitness and reduction of fatigue in MS patients affected by mild or moderate disability. MS patients can positively adapt to resistance training which may result in improved fatigue and ambulation. Flexibility exercises such as stretching the muscles may diminish spasticity and prevent future painful contractions. Balance exercises have beneficial effects on fall rates and better balance. Some general guidelines exist for exercise recommendation in the MS population. The individualized exercise program should be designed to address a patient's chief complaint, improve strength, endurance, balance, coordination, fatigue and so on. An exercise staircase model has been proposed for exercise prescription and progression for a broad spectrum of MS patients.
CONCLUSION
Exercise should be considered as a safe and effective means of rehabilitation in MS patients. Existing evidence shows that a supervised and individualized exercise program may improve fitness, functional capacity and quality of life as well as modifiable impairments in MS patients.
Topics: Cognition; Cognitive Dysfunction; Depression; Disabled Persons; Exercise; Exercise Therapy; Fatigue; Gait; Humans; Multiple Sclerosis; Muscle Spasticity; Muscle Strength; Muscle Weakness; Pain; Paresis; Physical Fitness; Quality of Life; Resistance Training; Walking
PubMed: 28915856
DOI: 10.1186/s12883-017-0960-9 -
F1000Research 2019Intensive care unit-acquired weakness (ICU-AW) is the most common neuromuscular impairment in critically ill patients. We discuss critical aspects of ICU-AW that have... (Review)
Review
Intensive care unit-acquired weakness (ICU-AW) is the most common neuromuscular impairment in critically ill patients. We discuss critical aspects of ICU-AW that have not been completely defined or that are still under discussion. Critical illness polyneuropathy, myopathy, and muscle atrophy contribute in various proportions to ICU-AW. Diagnosis of ICU-AW is clinical and is based on Medical Research Council sum score and handgrip dynamometry for limb weakness and recognition of a patient's ventilator dependency or difficult weaning from artificial ventilation for diaphragmatic weakness (DW). ICU-AW can be caused by a critical illness polyneuropathy, a critical illness myopathy, or muscle disuse atrophy, alone or in combination. Its diagnosis requires both clinical assessment of muscle strength and complete electrophysiological evaluation of peripheral nerves and muscles. The peroneal nerve test (PENT) is a quick simplified electrophysiological test with high sensitivity and good specificity that can be used instead of complete electrophysiological evaluation as a screening test in non-cooperative patients. DW, assessed by bilateral phrenic nerve magnetic stimulation or diaphragm ultrasound, can be an isolated event without concurrent limb muscle involvement. Therefore, it remains uncertain whether DW and limb weakness are different manifestations of the same syndrome or are two distinct entities. Delirium is often associated with ICU-AW but a clear correlation between these two entities requires further studies. Artificial nutrition may have an impact on ICU-AW, but no study has assessed the impact of nutrition on ICU-AW as the primary outcome. Early mobilization improves activity limitation at hospital discharge if it is started early in the ICU, but beneficial long-term effects are not established. Determinants of ICU-AW can be many and can interact with each other. Therefore, future studies assessing early mobilization should consider a holistic patient approach with consideration of all components that may lead to muscle weakness.
Topics: Critical Illness; Diaphragm; Hand Strength; Humans; Intensive Care Units; Muscle Weakness; Muscular Atrophy; Muscular Diseases; Polyneuropathies; Respiration, Artificial
PubMed: 31069055
DOI: 10.12688/f1000research.17376.1 -
Orthopaedics & Traumatology, Surgery &... Feb 2018Neuromuscular diseases (NMDs) affect the peripheral nervous system, which includes the motor neurons and sensory neurons; the muscle itself; or the neuromuscular... (Review)
Review
Neuromuscular diseases (NMDs) affect the peripheral nervous system, which includes the motor neurons and sensory neurons; the muscle itself; or the neuromuscular junction. Thus, the term NMDs encompasses a vast array of different syndromes. Some of these syndromes are of direct relevance to paediatric orthopaedic surgeons, either because the presenting manifestation is a functional sign (e.g., toe-walking) or deformity (e.g., pes cavus or scoliosis) suggesting a need for orthopaedic attention or because orthopaedic abnormalities requiring treatment develop during the course of a known NMD. The main NMDs relevant to the orthopaedic surgeon are infantile spinal muscular atrophy (a motor neuron disease), peripheral neuropathies (chiefly, Charcot-Marie-Tooth disease), congenital muscular dystrophies, progressive muscular dystrophies, and Steinert myotonic dystrophy (or myotonic dystrophy type 1). Muscle weakness is a symptom shared by all these conditions. The paediatric orthopaedic surgeon must be familiar, not only with the musculoskeletal system, but also with many other domains (particularly respiratory and cardiac function and nutrition) that may interfere with the treatment and require preoperative management. Good knowledge of the natural history of each NMD is essential to ensure optimal timing of the therapeutic interventions, which must be performed under the best possible conditions in these usually frail patients. Timing is particularly crucial for the treatment of spinal deformities due to paraspinal muscle hypotonia during growth: depending on the disease and natural history, the treatment may involve non-operative methods or growing rods, followed by spinal fusion. A multidisciplinary approach is always required. Finally, the survival gains achieved in recent years increasingly require attention to preparing for adult life, to orthopaedic problems requiring treatment before the patient leaves the paediatric environment, and to the transition towards the adult healthcare system.
Topics: Adult; Child; Humans; Muscle Weakness; Neuromuscular Diseases; Orthopedics; Pediatrics; Preoperative Care; Scoliosis
PubMed: 29196274
DOI: 10.1016/j.otsr.2017.04.019 -
International Journal of Molecular... Oct 2020Intensive care unit-acquired weakness (ICUAW) occurs in critically ill patients stemming from the critical illness itself, and results in sustained disability long after... (Review)
Review
Intensive care unit-acquired weakness (ICUAW) occurs in critically ill patients stemming from the critical illness itself, and results in sustained disability long after the ICU stay. Weakness can be attributed to muscle wasting, impaired contractility, neuropathy, and major pathways associated with muscle protein degradation such as the ubiquitin proteasome system and dysregulated autophagy. Furthermore, it is characterized by the preferential loss of myosin, a distinct feature of the condition. While many risk factors for ICUAW have been identified, effective interventions to offset these changes remain elusive. In addition, our understanding of the mechanisms underlying the long-term, sustained weakness observed in a subset of patients after discharge is minimal. Herein, we discuss the various proposed pathways involved in the pathophysiology of ICUAW, with a focus on the mechanisms underpinning skeletal muscle wasting and impaired contractility, and the animal models used to study them. Furthermore, we will explore the contributions of inflammation, steroid use, and paralysis to the development of ICUAW and how it pertains to those with the corona virus disease of 2019 (COVID-19). We then elaborate on interventions tested as a means to offset these decrements in muscle function that occur as a result of critical illness, and we propose new strategies to explore the molecular mechanisms of ICUAW, including serum-related biomarkers and 3D human skeletal muscle culture models.
Topics: Animals; COVID-19; Coronavirus Infections; Critical Care; Humans; Iatrogenic Disease; Muscle Weakness; Muscular Atrophy; Pandemics; Pneumonia, Viral
PubMed: 33105809
DOI: 10.3390/ijms21217840 -
Physiological Reviews Jul 2015Critical illness polyneuropathies (CIP) and myopathies (CIM) are common complications of critical illness. Several weakness syndromes are summarized under the term... (Review)
Review
Critical illness polyneuropathies (CIP) and myopathies (CIM) are common complications of critical illness. Several weakness syndromes are summarized under the term intensive care unit-acquired weakness (ICUAW). We propose a classification of different ICUAW forms (CIM, CIP, sepsis-induced, steroid-denervation myopathy) and pathophysiological mechanisms from clinical and animal model data. Triggers include sepsis, mechanical ventilation, muscle unloading, steroid treatment, or denervation. Some ICUAW forms require stringent diagnostic features; CIM is marked by membrane hypoexcitability, severe atrophy, preferential myosin loss, ultrastructural alterations, and inadequate autophagy activation while myopathies in pure sepsis do not reproduce marked myosin loss. Reduced membrane excitability results from depolarization and ion channel dysfunction. Mitochondrial dysfunction contributes to energy-dependent processes. Ubiquitin proteasome and calpain activation trigger muscle proteolysis and atrophy while protein synthesis is impaired. Myosin loss is more pronounced than actin loss in CIM. Protein quality control is altered by inadequate autophagy. Ca(2+) dysregulation is present through altered Ca(2+) homeostasis. We highlight clinical hallmarks, trigger factors, and potential mechanisms from human studies and animal models that allow separation of risk factors that may trigger distinct mechanisms contributing to weakness. During critical illness, altered inflammatory (cytokines) and metabolic pathways deteriorate muscle function. ICUAW prevention/treatment is limited, e.g., tight glycemic control, delaying nutrition, and early mobilization. Future challenges include identification of primary/secondary events during the time course of critical illness, the interplay between membrane excitability, bioenergetic failure and differential proteolysis, and finding new therapeutic targets by help of tailored animal models.
Topics: Animals; Biomechanical Phenomena; Critical Illness; Disease Models, Animal; Energy Metabolism; Excitation Contraction Coupling; Humans; Inflammation Mediators; Intensive Care Units; Ion Channels; Mechanotransduction, Cellular; Molecular Motor Proteins; Muscle Weakness; Muscle, Skeletal; Muscular Diseases; Polyneuropathies; Predictive Value of Tests; Risk Factors
PubMed: 26133937
DOI: 10.1152/physrev.00028.2014 -
Current Opinion in Critical Care Aug 2022To summarize the incidence, features, pathogenesis, risk factors, and evidence-based therapies of prolonged intensive care unit (ICU) acquired weakness (ICU-AW). We aim... (Review)
Review
PURPOSE OF REVIEW
To summarize the incidence, features, pathogenesis, risk factors, and evidence-based therapies of prolonged intensive care unit (ICU) acquired weakness (ICU-AW). We aim to provide an updated overview on aspects of poor physical recovery following critical illness.
RECENT FINDINGS
New physical problems after ICU survival, such as muscle weakness, weakened condition, and reduced exercise capacity, are the most frequently encountered limitations of patients with postintensive care syndrome. Disabilities may persist for months to years and frequently do not fully recover. Hormonal and mitochondrial disturbances, impaired muscle regeneration due to injured satellite cells and epigenetic differences may be involved in sustained ICU-AW. Although demographics and ICU treatment factors appear essential determinants for physical recovery, pre-ICU health status is also crucial. Currently, no effective treatments are available. Early mobilization in the ICU may improve physical outcomes at ICU-discharge, but there is no evidence for benefit on long-term physical recovery.
SUMMARY
Impaired physical recovery is observed frequently among ICU survivors. The pre-ICU health status, demographic, and ICU treatment factors appear to be important determinants for physical convalescence during the post-ICU phase. The pathophysiological mechanisms involved are poorly understood, thereby resulting in exiguous evidence-based treatment strategies to date.
Topics: Critical Illness; Humans; Incidence; Intensive Care Units; Muscle Weakness; Risk Factors
PubMed: 35796071
DOI: 10.1097/MCC.0000000000000955