Diagnosis and Differential Diagnosis
Marc H. De Baets, Hans J.G.H. Oosterhuis in Myasthenia Gravis, 2019
If any of these symptoms or signs is present and cannot be explained unequivocally by another disease, it is mandatory to prove that it is due to muscle weakness. The next and still more important step is that this weakness is exaggerated or elicited by exertion and improves after a period of rest. This phenomenon is nearly always a part of the patient’s history especially at onset of the disease and can be observed during the history taking. Exceptions are some patients who report that their ptosis or diplopia is worse after sleep but improves in the next hour. The tests in Table 2, Chapter 2 have proved to be very useful in search for myasthenic weakness; they are simple, quantifiable and perform-able in the consulting room or at the bedside. These tests have been used by the author for more than 20 years and the normal values are reliable.
Medicolegal considerations of cosmetic treatment with botulinum toxin injections
Anthony V. Benedetto in Botulinum Toxins in Clinical Aesthetic Practice, 2017
Several years ago, the FDA mandated a “black box warning” for manufacturers selling botulinum toxins in the United States. Such mandatory information, must be provided with every vial of sold botulinum toxin. The warning contains the following: Read this information this time and every time you get botulinum toxin.Share this information with your family and caregivers.Problems with swallowing, speaking, or breathing may occur.These problems may occur weeks after the injections.Swallowing problems may require a feeding tube.Muscle weakness may occur all over the body.Loss over bladder control may occur.Death can happen.These problems could make it unsafe for you to drive a car or do other dangerous activities.This medication guide has been approved by the FDA.
Fifi
Walter J. Hendelman, Peter Humphreys, Christopher R. Skinner in The Integrated Nervous System, 2017
In general, a dysfunction of a proportion of motor units in a given muscle will produce difficulty in generating normal amounts of tension in the muscle when an attempt is made to contract it: exactly the problem Fifi has developed. Nevertheless, it is unlikely that Fifi has a specific problem of either AHC or muscle fiber function for the simple reason that she also has sensory symptoms. While it is possible that her disease process might be simultaneously affecting AHCs, muscles and sensory nerve fibers, as a general rule, such a scenario is unlikely. In large part, the most economical explanation for the location of a disease process is also the most likely.1 This being the case, the most probable explanation for the muscle weakness is a process affecting motor axons, with the sensory axons also being involved to a lesser extent.
Portable fixed dynamometry enables home-based, reliable assessment of muscle strength in patients with amyotrophic lateral sclerosis: a pilot study
Published in Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration, 2023
Jordi W. J. Van Unnik, Jaap N.E. Bakers, Steure Kokx, Leonard H. Van Den Berg, Johanna M.A. Visser-Meily, Anita Beelen, Ruben P.A. Van Eijk
Progressive loss of muscle strength is regarded as the hallmark of disease progression in ALS and is reported by patients, together with respiratory function, as the most important outcome for home-monitoring (24). The severity of muscle weakness influences the ability to perform activities of daily living, making it a crucial outcome for assessing disease progression and detecting (early) treatment responses of new therapeutic interventions. The importance of muscle strength in the search for new effective therapies (6,7,37), and the current shift toward remote monitoring (24,25), stress the need for methods that allow unsupervised home-based assessment of muscle strength. Home-based assessment of muscle strength may alleviate travel burden for patients and reduce the burden of participating in clinical trials, while providing a more complete understanding of patient functioning in daily life. With a view to care, remote monitoring of muscle strength may aid the facilitation of personalized visit schemes to reduce travel burden (30,38), increase access to multidisciplinary care, and improve quality of life (39,40).
Treatment considerations in myasthenia gravis for the pregnant patient
Published in Expert Review of Neurotherapeutics, 2023
Nils Erik Gilhus
Myasthenia gravis (MG) is an autoimmune disease where antibodies against the acetylcholine receptor (AChR) in the postsynaptic membrane at the neuromuscular junction cause the typical muscle weakness [1,2]. More rarely, pathogenic antibodies are instead directed against muscle-specific kinase (MuSK) or lipoprotein-related protein 4 (LRP4) antigens functionally linked to AChR in the membrane. The muscle weakness can be generalized or localized. It occurs most frequently in extraocular muscles with diplopia and ptosis as troublesome symptoms. Weakness in swallowing and speech muscles as well as in facial muscles is common. Neck, shoulder, and arm muscles have frequently some weakness, whereas leg muscles are rarely affected [3]. Respiratory muscle weakness represents the major threat of MG, and myasthenic crisis with the need of ventilatory support can occur, especially during respiratory infections. Fluctuations during the day and over time are typical for MG. Repetitive and prolonged muscle use increases or precipitates the weakness.
Rare forms of inflammatory myopathies - part II, localized forms
Published in Expert Review of Clinical Immunology, 2023
Claudio Galluzzo, Ilaria Chiapparoli, Ada Corrado, Francesco Paolo Cantatore, Carlo Salvarani, Nicolò Pipitone
Macrophagic myofasciitis is considered a reaction to hepatitis A, B or tetanus toxoid vaccines containing aluminum. It has mainly been described in middle-aged patients and is clinically characterized by diffuse myalgia and fatigue, although few patients fulfill the 1990 American College of Rheumatology criteria for fibromyalgia. Muscle weakness is rare. Myopathic EMG changes and (mostly modest) CK elevation are found in fewer than half of patients. Histology shows focal infiltration of the epimysium, perimysium and perifascicular endomysium by macrophages with a minor lymphocytic component, mainly consisting of CD8 + T cells forming perivascular cuffs; occasionally B cells (rarely forming lymphoid follicles) and CD138+ plasma cells may be detected. Giant multinucleated cells are absent, and muscle fiber necrosis inconspicuous or lacking. There is no widespread HLA-I expression on muscle fibers nor MAC deposition on capillaries. Aluminum salts are stained by hematoxylin, although not in formalin-fixed material, probably due to artifacts. Macrophagic myofasciitis tends to persist if untreated, but responds to glucocorticoids at doses ranging from 0.3 mg to 1 mg/kg/day of prednisone-equivalent tapering [65].
Related Knowledge Centers
- Muscle
- Muscular Dystrophy
- Neuromuscular Junction
- Potassium
- Myasthenia Gravis
- Inflammatory Myopathy
- Electrolyte
- Weakness
- Nerve
- Synaptic Fatigue