Wooden breast myopathy on broiler breast fillets affects quality and consumer preference.

INTRODUCTION: The emergence of myopathies such as wooden breast in the poultry industry generally associated with the fast development of the breast muscle of broilers has provided changes in the morphological structure of muscle tissues, as well as problems of meat qualitative attributes. The aim of this study was to evaluate physical, chemical, qualitative, and sensorial attributes of broiler fillets associated with severity levels of wooden breast (WB) myopathy in a poultry slaughterhouse. MATERIALS AND METHODS: Three hundred fillets in a poultry slaughterhouse were classified into three severity levels: normal (100 samples), moderate (100 samples), and severe (100 samples). RESULTS: After identification, classification, and description of changes, fillets with a severe WB level presented higher levels of red (a*), yellow (b*), and final pH. The lowest shear force and the highest myofibrillar fragmentation index were observed in fillets with a severe level when compared with normal fillets. The collagen content increased according to severity level. Tasters better evidenced the characteristic taste of chicken meat when tasting fillets with a severe WB level when compared with normal and moderate fillets. The succulence and preference of the Brazilian testers increased according to the severity level of the myopathy. CONCLUSION: In general, fillets with moderate and severe WB myopathy were affected not only in appearance but also in qualitative, physical, chemical, and sensory characteristics.

Common Running Injuries: Evaluation and Management.

Running is a common form of exercise but predisposes athletes to several running-related injuries. Most running injuries are due to overuse and respond to conservative treatment. Tendinopathies in the patellar, Achilles, and hamstring tendons are common, and are primarily treated with eccentric exercise. Iliotibial band syndrome and patellofemoral pain syndrome are less common than patellar tendinopathy and are treated by strengthening exercises for the core and legs in addition to flexibility exercises. Acute hamstring strains and medial tibial stress syndrome require a period of relative rest, followed by stretching and graded return to activity. Tibial stress fractures require an extended period of relative rest, followed by a more gradual return to activity. Early mobilization improves recovery from ankle sprains, and exercise therapy and functional bracing while running for six to 12 months prevents reinjury. Plantar fasciopathy (plantar fasciitis) can be significantly improved with stretching, heel raises, and orthoses that provide arch support.

Axial myopathy: an overlooked feature of muscle diseases.

Classically, myopathies are categorized according to limb or cranial nerve muscle affection, but with the growing use of magnetic resonance imaging it has become evident that many well-known myopathies have significant involvement of the axial musculature. New disease entities with selective axial muscle involvement have also been described recently, but overall the axial myopathy is unexplored. We performed a PubMed search using the search terms 'myopathy', 'paraspinal', 'axial' and 'erector'. Axial myopathy was defined as involvement of paraspinal musculature. We found evidence of axial musculature involvement in the majority of myopathies in which paraspinal musculature was examined. Even in diseases named after a certain pattern of non-axial muscle affection, such as facioscapulohumeral and limb girdle muscular dystrophies, affection of the axial musculature was often severe and early, compared to other muscle groups. Very sparse literature evaluating the validity of clinical assessment methods, electromyography, muscle biopsy and magnetic resonance imaging was identified and reference material is generally missing. This article provides an overview of the present knowledge on axial myopathy with the aim to increase awareness and spur interest among clinicians and researchers in the field.

Myotonic Disorders and Channelopathies.

Myotonic dystrophies and channelopathies are rare but important causes of muscle diseases which may present with myotonia, episodic attacks of weakness, fixed muscle weakness, and atrophy or their combination. Here, the authors provide an overview of these disorders and describe their clinical and pathophysiological features, diagnostic methods, and management.

British athletics muscle injury classification: a reliability study for a new grading system.

AIM: To implement and validate the newly proposed British athletics muscle injury classification in the assessment of hamstring injuries in track and field athletes and to analyse the nature and frequency of the discrepancies. MATERIALS AND METHODS: This was a retrospective study analysing hamstring injuries in elite British athletes using the proposed classification system. Classification of 65 hamstring injuries in 45 high-level athletes by two radiologists at two time points 4 months apart to determine interrater variability, intrarater variability, and feasibility of the classification system was undertaken. RESULTS: Interrater Kappa values of 0.80 (95% confidence interval [CI]: 0.67-0.92; p<0.0001) for Round 1 and 0.88 (95% CI: 0.76-1.00; p<0.0001) for Round 2 of the review were observed. Percentages of agreement were 85% for Round 1 and 91% for Round 2. The intrarater Kappa value for the two reviewers were 0.76 (95% CI: 0.63-0.88; p<0.0001) and 0.65 (95% CI: 0.53-0.76; p<0.0001) and the average was 0.71 suggesting substantial overall agreement. The percentages of agreement were 82% and 72%, respectively. CONCLUSIONS: This classification system is straightforward to use and produces both reproducible and consistent results based on interrater and intrarater Kappa values with at least substantial agreement in all groups. Further work is ongoing to investigate whether individual grades within this classification system provide prognostic information and could guide clinical management.

[Ultrasound examination in diagnosis and classification of occupational myofibrosis (lecture)].

Based on comparative analysis of contemporary clinical and instrumental investigations, the authors justify advantage of ultrasound examination in diagnosis of occupational myofibrosis. Results of ultrasound application helped to specify a classification of occupational myofibrosis according to the disease severity, that considerably increases efficiency of examining connection between the disease and occupation.

Mutation update: the spectra of nebulin variants and associated myopathies.

A mutation update on the nebulin gene (NEB) is necessary because of recent developments in analysis methodology, the identification of increasing numbers and novel types of variants, and a widening in the spectrum of clinical and histological phenotypes associated with this gigantic, 183 exons containing gene. Recessive pathogenic variants in NEB are the major cause of nemaline myopathy (NM), one of the most common congenital myopathies. Moreover, pathogenic NEB variants have been identified in core-rod myopathy and in distal myopathies. In this update, we present the disease-causing variants in NEB in 159 families, 143 families with NM, and 16 families with NM-related myopathies. Eighty-eight families are presented here for the first time. We summarize 86 previously published and 126 unpublished variants identified in NEB. Furthermore, we have analyzed the NEB variants deposited in the Exome Variant Server (http://evs.gs.washington.edu/EVS/), identifying that pathogenic variants are a minor fraction of all coding variants (∼7%). This indicates that nebulin tolerates substantial changes in its amino acid sequence, providing an explanation as to why variants in such a large gene result in relatively rare disorders. Lastly, we discuss the difficulties of drawing reliable genotype-phenotype correlations in NEB-associated disease.

Natural history of pulmonary function in collagen VI-related myopathies.

The spectrum of clinical phenotypes associated with a deficiency or dysfunction of collagen VI in the extracellular matrix of muscle are collectively termed 'collagen VI-related myopathies' and include Ullrich congenital muscular dystrophy, Bethlem myopathy and intermediate phenotypes. To further define the clinical course of these variants, we studied the natural history of pulmonary function in correlation to motor abilities in the collagen VI-related myopathies by analysing longitudinal forced vital capacity data in a large international cohort. Retrospective chart reviews of genetically and/or pathologically confirmed collagen VI-related myopathy patients were performed at 10 neuromuscular centres: USA (n = 2), UK (n = 2), Australia (n = 2), Italy (n = 2), France (n = 1) and Belgium (n = 1). A total of 486 forced vital capacity measurements obtained in 145 patients were available for analysis. Patients at the severe end of the clinical spectrum, conforming to the original description of Ullrich congenital muscular dystrophy were easily identified by severe muscle weakness either preventing ambulation or resulting in an early loss of ambulation, and demonstrated a cumulative decline in forced vital capacity of 2.6% per year (P < 0.0001). Patients with better functional abilities, in whom walking with/without assistance was achieved, were initially combined, containing both intermediate and Bethlem myopathy phenotypes in one group. However, one subset of patients demonstrated a continuous decline in pulmonary function whereas the other had stable pulmonary function. None of the patients with declining pulmonary function attained the ability to hop or run; these patients were categorized as intermediate collagen VI-related myopathy and the remaining patients as Bethlem myopathy. Intermediate patients had a cumulative decline in forced vital capacity of 2.3% per year (P < 0.0001) whereas the relationship between age and forced vital capacity in patients with Bethlem myopathy was not significant (P = 0.1432). Nocturnal non-invasive ventilation was initiated in patients with Ullrich congenital muscular dystrophy by 11.3 years (±4.0) and in patients with intermediate collagen VI-related myopathy by 20.7 years (±1.5). The relationship between maximal motor ability and forced vital capacity was highly significant (P < 0.0001). This study demonstrates that pulmonary function profiles can be used in combination with motor function profiles to stratify collagen VI-related myopathy patients phenotypically. These findings improve our knowledge of the natural history of the collagen VI-related myopathies, enabling proactive optimization of care and preparing this patient population for clinical trials.

Assessment of fatty degeneration of the gluteal muscles in patients with THA using MRI: reliability and accuracy of the Goutallier and quartile classification systems.

The purpose of this study was to quantify the performance of the Goutallier classification for assessing fatty degeneration of the gluteus muscles from magnetic resonance (MR) images and to compare its performance to a newly proposed system. Eighty-four hips with clinical signs of gluteal insufficiency and 50 hips from asymptomatic controls were analyzed using a standard classification system (Goutallier) and a new scoring system (Quartile). Interobserver reliability and intraobserver repeatability were determined, and accuracy was assessed by comparing readers' scores with quantitative estimates of the proportion of intramuscular fat based on MR signal intensities (gold standard). The existing Goutallier classification system and the new Quartile system performed equally well in assessing fatty degeneration of the gluteus muscles, both showing excellent levels of interrater and intrarater agreement. While the Goutallier classification system has the advantage of being widely known, the benefit of the Quartile system is that it is based on more clearly defined grades of fatty degeneration.

Muscle diseases: mimics and chameleons.

Muscle diseases are not as common as headaches and funny turns in our general neurology clinics, but most of us will encounter them. We all pride ourselves on a methodical approach to clinical problems-discovering the where and what in neurological parlance-but any diagnostic process can unravel, particularly if one condition resembles another. Before we settle on a diagnosis, we need to ask ourselves, whether the 'ducks all line up' to avoid cases of mistaken identity.

Genetic and clinical characteristics of skeletal and cardiac muscle in patients with lamin A/C gene mutations.

Alterations of the lamin A/C (LMNA) gene are associated with different clinical entities, including disorders that affect skeletal and cardiac muscle, peripheral nerves, metabolism, bones, and disorders that cause premature aging. In this article we review the clinical and genetic characteristics of cardiac and skeletal muscle diseases related to alterations in the LMNA gene. There is no single explanation of how LMNA gene alterations may cause these disorders; however, important goals have been achieved in understanding the pathogenic effects of LMNA gene mutations on cardiac and skeletal muscle.

Modifying the Medical Research Council grading system through Rasch analyses.

The Medical Research Council grading system has served through decades for the evaluation of muscle strength and has been recognized as a cardinal feature of daily neurological, rehabilitation and general medicine examination of patients, despite being respectfully criticized due to the unequal width of its response options. No study has systematically examined, through modern psychometric approach, whether physicians are able to properly use the Medical Research Council grades. The objectives of this study were: (i) to investigate physicians' ability to discriminate among the Medical Research Council categories in patients with different neuromuscular disorders and with various degrees of weakness through thresholds examination using Rasch analysis as a modern psychometric method; (ii) to examine possible factors influencing physicians' ability to apply the Medical Research Council categories through differential item function analyses; and (iii) to examine whether the widely used Medical Research Council 12 muscles sum score in patients with Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy would meet Rasch model's expectations. A total of 1065 patients were included from nine cohorts with the following diseases: Guillain-Barré syndrome (n = 480); myotonic dystrophy type-1 (n = 169); chronic inflammatory demyelinating polyradiculoneuropathy (n = 139); limb-girdle muscular dystrophy (n = 105); multifocal motor neuropathy (n = 102); Pompe's disease (n = 62) and monoclonal gammopathy of undetermined related polyneuropathy (n = 8). Medical Research Council data of 72 muscles were collected. Rasch analyses were performed on Medical Research Council data for each cohort separately and after pooling data at the muscle level to increase category frequencies, and on the Medical Research Council sum score in patients with Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy. Disordered thresholds were demonstrated in 74-79% of the muscles examined, indicating physicians' inability to discriminate between most Medical Research Council categories. Factors such as physicians' experience or illness type did not influence these findings. Thresholds were restored after rescoring the Medical Research Council grades from six to four options (0, paralysis; 1, severe weakness; 2, slight weakness; 3, normal strength). The Medical Research Council sum score acceptably fulfilled Rasch model expectations after rescoring the response options and creating subsets to resolve local dependency and item bias on diagnosis. In conclusion, a modified, Rasch-built four response category Medical Research Council grading system is proposed, resolving clinicians' inability to differentiate among its original response categories and improving clinical applicability. A modified Medical Research Council sum score at the interval level is presented and is recommended for future studies in Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy.

Terminology and classification of muscle injuries in sport: the Munich consensus statement.

OBJECTIVE: To provide a clear terminology and classification of muscle injuries in order to facilitate effective communication among medical practitioners and development of systematic treatment strategies. METHODS: Thirty native English-speaking scientists and team doctors of national and first division professional sports teams were asked to complete a questionnaire on muscle injuries to evaluate the currently used terminology of athletic muscle injury. In addition, a consensus meeting of international sports medicine experts was established to develop practical and scientific definitions of muscle injuries as well as a new and comprehensive classification system. RESULTS: The response rate of the survey was 63%. The responses confirmed the marked variability in the use of the terminology relating to muscle injury, with the most obvious inconsistencies for the term strain. In the consensus meeting, practical and systematic terms were defined and established. In addition, a new comprehensive classification system was developed, which differentiates between four types: functional muscle disorders (type 1: overexertion-related and type 2: neuromuscular muscle disorders) describing disorders without macroscopic evidence of fibre tear and structural muscle injuries (type 3: partial tears and type 4: (sub)total tears/tendinous avulsions) with macroscopic evidence of fibre tear, that is, structural damage. Subclassifications are presented for each type. CONCLUSIONS: A consistent English terminology as well as a comprehensive classification system for athletic muscle injuries which is proven in the daily practice are presented. This will help to improve clarity of communication for diagnostic and therapeutic purposes and can serve as the basis for future comparative studies to address the continued lack of systematic information on muscle injuries in the literature. WHAT ARE THE NEW THINGS: Consensus definitions of the terminology which is used in the field of muscle injuries as well as a new comprehensive classification system which clearly defines types of athletic muscle injuries. LEVEL OF EVIDENCE: Expert opinion, Level V.

Congenital myopathies: clinical and immunohistochemical study.

Congenital myopathies (CMs), a group of relatively non-progressive disorders presents with weakness and hypotonia of varying severity, morphologically recognized by specific structural abnormalities within the myofiber. This report presents the clinical and Histopathological features of 40 patients with CMs. Centronuclear myopathy was the commonest (40%) followed by congenital fiber type disproportion (37.5%). Other less common CMs included: myotubular myopathy (5%), nemaline myopathy (5%), central core disease (5%), multicore disease (2.5%) and congenital myopathy with tubular aggregate (5%). Immunolabeling to desmin corresponded to morphological changes within the myofibers while vimentin was negative in all the patients. There is no combined role of these proteins in the disease process.

Orthopaedic abnormalities in primary myopathies.

Orthopaedic abnormalities are frequently recognised in patients with myopathy but are hardly systematically reviewed with regard to type of myopathy, type of orthopaedic problem, and orthopaedic management. This review aims to summarize recent findings and current knowledge about orthopaedic abnormalities in these patients, their frequency, and possible therapeutic interventions. A MEDLINE search for the combination of specific terms was carried out and appropriate articles were reviewed for the type of myopathy, types of orthopaedic abnormalities, frequency of orthopaedic abnormalities, and possible therapeutic interventions. Orthopaedic abnormalities in myopathies can be most simply classified according to the anatomical location into those of: the spine, including dropped head, camptocormia, scoliosis, hyperlordosis, hyperkyphosis, or rigid spine; the thorax, including pectus excavatum (cobbler's chest), anterior/posterior flattening, or pectus carinatum (pigeon's chest); the limb girdles, including scapular winging and pelvic deformities; and the extremities, including contractures, hyperlaxity of joints, and hand or foot deformities. These orthopaedic abnormalities can be most frequently found in arthrogryposis, muscular dystrophies, congenital myopathies, myofibrillar myopathies, and myotonic dystrophies. Occasionally, they also occur in metabolic myopathies or other types of myopathy. Most of the orthopaedic abnormalities are sufficiently accessible to conservative or surgical orthopaedic treatment. Orthopaedic abnormalities have major implications in the management and outcome of myopathy patients; they should be closely monitored and treated on time.

[Diagnosis of myopathies]. / Diagnose von Myopathien.

Although the diagnostic work-up for myopathies can be difficult, it should be carried out for medical and financial reasons if the suspicion is supported by evidence. The diagnosis is based on the history, neurological investigation, blood chemical investigations at rest and under stress, electromyography, muscle MRI, biopsy, the in-vitro coffeine-halothan contracture test, and molecular genetic studies. There is some role for muscle enzyme determinations in the diagnostic work-up, although these values are frequently multifactorial. However, if muscle enzymes are repeatedly increased without explanation but in the presence of muscular symptoms, the diagnostic work-up should be initiated. Stress tests can be of some additional help. Needle electromyography may be normal, myogenic, neurogenic or non-specifically abnormal. Muscle MRI may show trophic disturbances, and may guide one to the muscle most adequate for biopsy. A muscle biopsy may be taken for a number of further investigations and may lead to the correct diagnosis. Only if there is a profound suspicion for a certain genetic defect, molecular genetic investigations should be initiated. In the case that a pathogenic mutation is found, genetic counselling, and assessment of the prognosis, and therapy can be initiated. For diagnostic, therapeutic and prognostic implications, diagnostic work-up should be carried out as soon as possible if myopathy is suspected.

[The role of skeletal muscle biopsy in the diagnosis of neuromuscular disorders]. / Rola biopsji miesnia szkieletowego w diagnostyce chorób nerwowo-miesniowych.

Muscle biopsy is required to provide a definitive diagnosis in many neuromuscular disorders. Biopsy findings may indicate whether the pathological process is of neurogenic or myopathic origin. The muscle biopsy may give important information on the course of the disease (acute or chronic) and on the disease stage and progression. The interpretation of muscle biopsy, including histochemical and ultrastructural analysis, is a key factor in the diagnosis of muscular dystrophies, glycogenoses, inflammatory myopathies and congenital myopathies. An assessment of muscle biopsy on electron microscopy enables a definite diagnosis of oculopharyngeal muscular dystrophy, mitochondrial myopathy or inclusion body myositis. This paper presents an overview of general indications for muscle biopsy, biopsy procedures, as well as transportation and preparation of muscle tissue for final microscopic analysis. The interpretation of specific microscopic findings and a brief discussion on the clinical usefulness of muscle biopsy in the era of molecular diagnosis are also presented.

Improved Criteria for the Classification of Titin Variants in Inherited Skeletal Myopathies.

BACKGROUND: Extensive genetic screening results in the identification of thousands of rare variants that are difficult to interpret. Because of its sheer size, rare variants in the titin gene (TTN) are detected frequently in any individual. Unambiguous interpretation of molecular findings is almost impossible in many patients with myopathies or cardiomyopathies. OBJECTIVE: To refine the current classification framework for TTN-associated skeletal muscle disorders and standardize the interpretation of TTN variants. METHODS: We used the guidelines issued by the American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) to re-analyze TTN genetic findings from our patient cohort. RESULTS: We identified in the classification guidelines three rules that are not applicable to titin-related skeletal muscle disorders; six rules that require disease-/gene-specific adjustments and four rules requiring quantitative thresholds for a proper use. In three cases, the rule strength need to be modified. CONCLUSIONS: We suggest adjustments are made to the guidelines. We provide frequency thresholds to facilitate filtering of candidate causative variants and guidance for the use and interpretation of functional data and co-segregation evidence. We expect that the variant classification framework for TTN-related skeletal muscle disorders will be further improved along with a better understanding of these diseases.