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Results for “Muscle Weakness”

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At least 793 records · Page 44Linked to original sources

PubMed2003

Function and bulk of respiratory and limb muscles in patients with cystic fibrosis.

Inspiratory muscle weakness due to lung hyperinflation and muscle wasting may occur in cystic fibrosis. We therefore measured diaphragm function and bulk in 18 stable patients with cystic fibrosis and 15 matched control subjects; the abdominal and quadriceps muscles were studied for comparison. We assessed diaphragm mass, abdominal muscle thickness, twitch transdiaphragmatic and gastric pressures, quadriceps cross-section and isokinetic strength, and lean body mass. Lean body mass, quadriceps strength, and quadriceps cross-section were lower in patients with cystic fibrosis. Twitch transdiaphragmatic pressure was 23% lower and twitch gastric pressure was 22% greater in patients with cystic fibrosis than in control subjects, but diaphragm mass and abdominal muscle thickness were similar in the two groups. For any given lean body mass and quadriceps cross-section, patients with cystic fibrosis had greater diaphragm mass and abdominal muscle thickness. Diaphragm mass had greater intersubject variability in patients with cystic fibrosis than in control subjects. We conclude that diaphragm strength is decreased but abdominal muscle strength is increased in patients with cystic fibrosis. Diaphragm and abdominal muscle bulk are not affected by the general muscle wasting, which suggests that there may be a training effect of cystic fibrosis on respiratory muscles. However, the variability of diaphragm mass indicates that this beneficial response does not occur in all patients with cystic fibrosis.

Abdominal Muscles↗

PubMedDate not supplied

[A patient of polymyositis with severe myocardial damage and conduction block].

A patient with polymyositis manifesting severe myocardial damage and conduction block is described. A 57-year-old man presented dysarthria, dysphagia, proximal-dominant muscle weakness and wasting of the extremities. Muscle biopsy revealed degeneration and regeneration of muscle fibers and infiltration of mononuclear cells. After admission, muscle weakness rapidly progressed and mechanical ventilation was needed for respiratory failure. Simultaneously, cardiac symptom developed and resulted in bradycardia and trifascicular conduction block, which required a pacemaker. Echocardiogram revealed diffuse hypokinesia, ventricular enlargement and thickened wall. Marked elevations of serum CK-MB, cardiac myosin light chain I and cardiac troponin T were observed. High dose administration of methylprednisolone resulted in improvement of muscular and cardiac symptoms, and prevented complete heart block. Immediate and high dose of steroid therapy was considered to be effective for severe myocarditis in polymyositis.

Cardiomyopathies↗

PubMed1998

Assessment of respiratory muscle function and strength.

Measurement of respiratory muscle strength is useful in order to detect respiratory muscle weakness and to quantify its severity. In patients with severe respiratory muscle weakness, vital capacity is reduced but is a non-specific and relatively insensitive measure. Conventionally, inspiratory and expiratory muscle strength has been assessed by maximal inspiratory and expiratory mouth pressures sustained for 1 s (PImax and PEmax) during maximal static manoeuvre against a closed shutter. However, PImax and PEmax are volitional tests, and are poorly reproducible with an average coefficient of variation of 25%. The sniff manoeuvre is natural and probably easier to perform. Sniff pressure, and sniff transdiaphragmatic pressure are more reproducible and useful measure of diaphragmatic strength. Nevertheless, the sniff manoeuvre is also volition-dependent, and submaximal efforts are most likely to occur in patients who are ill or breathless. Non-volitional tests include measurements of twitch oesophageal, gastric and transdiaphragmatic pressure during bilateral electrical and magnetic phrenic nerve stimulation. Electrical phrenic nerve stimulation is technically difficult and is also uncomfortable and painful. Magnetic phrenic nerve stimulation is less painful and transdiaphragmatic pressure is reproducible in normal subjects. It is a relatively easy test that has the potential to become a widely adopted method for the assessment of diaphragm strength. The development of a technique to measure diaphragmatic sound (phonomyogram) during magnetic phrenic nerve stimulation opens the way for noninvasive assessment of diaphragmatic function.

Electric Stimulation↗

PubMedDate not supplied

[Nemaline congenital myopathy:clinical features and histopathological findings in nine patients].

INTRODUCTION: Nemaline myopathy is a type of congenital myopathy which presents with hypotonia, muscle weakness which is predominantly proximal, lax ligaments, areflexia and skeletal deformities. It is characterized by the presence of intrasarcolemal or intranuclear rods which can be seen with the red color optical microscope using the Gomori technique, and a defect in the Z line of the sarcomere, detected on electron microscopy (EM). PATIENTS AND METHODS: A retrospective study of the cases of nemaline congenital myopathy diagnosed in our hospital between 1984 and 1997. All patients had clinical laboratory analysis (muscle enzymes), and electromyographic and histopathological (muscle biopsy) studies. In 5 cases EM was done. RESULTS: Nine patients, four males and five females were studied. Diagnosis was made during the first year of life in 7 cases (77.7%), and was characterized by hypotonia, severe areflexia and proximal muscle weakness, whilst the remainder were diagnosed in adolescence when they presented with a juvenile form of the disorder, with muscle weakness, amyotrophy and scoliosis. Muscle biopsy showed nemaline bodies in a variable proportion of fibres. Intranuclear rods were not identified in any case. In the 5 cases in which ultrastructural studies were done, alterations were detected in the Z line of the sarcomere. The immunohistochemical profile of the rods was positive for alphaactin. CONCLUSIONS: There are no clinical features which permit distinction from other forms of congenital myopathy, so muscle biopsy is necessary for diagnosis. There is great phenotype and prognostic variety in this disorder.

Actins↗

PubMed2004

Clinical disease severity and axonal dysfunction in hereditary motor and sensory neuropathy Ia.

BACKGROUND: Hereditary motor and sensory neuropathy type Ia (HMSN Ia) is known as a primarily demyelinating peripheral nerve disease. Evidence is accumulating that axonal involvement determines the course of the disease process. METHODS: Fifty-one patients were investigated. Physical disability and impairments were scored. Nerve conduction velocities (NCVs) were used as indirect measures for myelination status and compound muscle/sensory nerve action potential (CMAP/SNAP) amplitudes served as indirect measures for axonal function. RESULTS: Median age was 39 years (range 6-69). Muscle weakness and sensory dysfunction was more severe in the legs than in the arms and distally more than proximally. However, more than 40% of the patients had proximal muscle weakness in the legs. Three point grip was used as representative of combined distal arm muscle groups. CMAP amplitude was the most important independent variable in a multiple linear regression model (forward selection) to explain the relation between three point grip strength and four different features, i. e., CMAP amplitude of the abductor pollicis brevis, median nerve MNCV, gender, and duration of signs and symptoms. The severity of axonal dysfunction was nerve length-dependent and was related to the myelination status. The mild physical disability due to both muscle weakness and sensory dysfunction was also related to axonal dysfunction. CONCLUSIONS: In HMSN Ia, clinical disease severity at the impairment and disability levels is related to the severity of axonal dysfunction. Our data support the hypothesis that the myelination status is one of the factors that determine the extent of axonal dysfunction later in life. Proximal weakness of the legs is encountered in a considerable proportion of our patients.

Action Potentials↗

PubMed1976

Retardation of symptoms of dystrophy in genetically dystrophic chickens by chemotherapy.

Chickens homozygous for muscular dystrophy were treated twice-daily with the serotonin antagonist, methysergide. Development of the dystrophic state was monitored by a test of skeletal muscle weakness, and by the characteristic marked evaluation of creatine phosphokinase (CPK) in the serum. The drug treatment prevented the onset of muscle weakness for 45 days ex ovo in all of the test animals, and for more than 60 days in 80% of them, in contrast to the untreated dystrophic animals. The CPK elevation in serum was also markedly reduced in the treated animals. A serotonin-mediated vascular effect or a direct action of serotonin on the muscle, is suggested to be involved in the development of muscle weakness in this form of dystrophy, and to be an appropriate target for chemotherapeutic control.

Aging↗

PubMed2002

Dermatomyositis: an overview of recent progress with emphasis on dermatologic aspects.

Important points regarding DM and C-ADM are as follows: C-ADM is a working functional designation for patients having the skin-only and skin-predominant subsets of DM, amyopathic DM, and hypomyopathic DM. C-ADM seems to have approximately 10% the incidence of classic DM in whites and possibly a higher incidence in Asians. Some patients who present with C-ADM, with or without subclinical laboratory abnormalities, can slowly progress to develop symptomatic muscle weakness over a period of years, whereas others go for 10 to 20 years and longer without the appearance of muscle weakness. C-ADM patients are at risk for potentially life-threatening complications of classic DM, such as interstitial lung disease, which may occur in up to 10% of C-ADM patients. This risk seems to be even greater in some ethnic subgroups (e.g., Japanese). C-ADM patients may also be at increased risk for internal malignancy and until further studies are carried out to confirm the statistical significance of this association, all such patients should have a thorough evaluation for internal malignancy, identical to the approach currently used in classic DM patients. Dermatologists are in the best position initially to diagnose C-ADM patients and can contribute greatly to their overall management and quality of life. Ongoing vigilance is required, however, for complications that can arise in C-ADM patients including potentially fatal interstitial lung disease, internal malignancy, delayed onset of muscle weakness from myositis, and complications of systemic drug therapy. Topical therapy with broad-spectrum sunscreens, anti-inflammatories, and antipruritics should be maximized during the initial management of the cutaneous manifestations of either classic DM or C-ADM. Single-agent or combined aminoquinoline antimalarial therapy represents the safest initial form of systemic therapy for DM-specific skin disease occurring in any clinical setting; however, this approach tends to be less effective in general than for cutaneous LE. There is a theoretical rationale for and limited preliminary successful anecdotal experience with the use of anti-TNF-alpha therapy in refractory cases of classic DM and C-ADM. Cautious systematic clinical trials in this area should be considered.

Dermatomyositis↗

PubMed1989

[A case of MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) with progressive cytochrome c oxidase deficiency].

We report a 9 year-old boy with MELAS. High dosed oral thiamine administration and high fat diet induced remarkable neurological and biochemical improvement. His mother had episodic headaches and hemiplegia, probably MELAS. He complained muscle weakness and repeated episodes of vomiting started from 2 years of age. High levels of serum lactate and pyruvate were recognized, but with no metabolic acidosis. He developed generalized muscle weakness, growth retardation, generalized convulsions and stroke-like episodes at 5 years old. Optic nerve atrophy and mental retardation gradually appeared. A muscle biopsy at 5 years old revealed numerous ragged-red fibers with excess accumulation of lipid droplets and glycogen particles. Scattered fibers had no cytochrome c oxidase (CCO) activity representing focal CCO deficiency. An electron microscopy showed markedly increased number of giant mitochondria filled with markedly proliferated complicated cristae. Pyruvate dehydrogenase complex level in the fibroblasts was within normal ranges. Serum carnitine level was normal. With oral administration of thiamine hydrochloride (1000 mg) and high fat diet (60-70%), muscle weakness improved, and lactate and pyruvate levels in the serum reduced to normal ranges, whereas the mental deterioration, muscle atrophy, pes cavus progressed very slowly. He died from cardiac and renal failures at 9 years old. Autopsied muscles showed a marked decrease in cytochrome c oxidase activity (biochemically 12.8% of the normal level), and almost all muscle fibers had no cytochrome c oxidase activity histochemically. The progression of the MELAS was probably in parallel with the decrease in CCO activity.

Acidosis, Lactic↗

PubMed1992

Perturbations of Drosophila alpha-actinin cause muscle paralysis, weakness, and atrophy but do not confer obvious nonmuscle phenotypes.

We have investigated accumulation of alpha-actinin, the principal cross-linker of actin filaments, in four Drosophila fliA mutants. A single gene is variably spliced to generate one nonmuscle and two muscle isoforms whose primary sequence differences are confined to a peptide spanning the actin binding domain and first central repeat. In fliA3 the synthesis of an adult muscle-specific isoform is blocked in flight and leg muscles, while in fliA4 the synthesis of nonmuscle and both muscle-specific isoforms is severely reduced. Affected muscles are weak or paralyzed, and, in the case of fliA3, atrophic. Their myofibrils, while structurally irregular, are remarkably normal considering that they are nearly devoid of a major contractile protein. Also surprising is that no obvious nonmuscle cell abnormalities can be discerned despite the fact that both the fliA1- and fliA4-associated mutations perturb the nonmuscle isoform. Our observations suggest that alpha-actinin stabilizes and anchors thin filament arrays, rather than orchestrating their assembly, and further imply that alpha-actinin function is redundant in both muscle and nonmuscle cells.

Actin Cytoskeleton↗

PubMed2006

Caspase activation contributes to endotoxin-induced diaphragm weakness.

Infections produce significant respiratory muscle weakness, but the mechanisms by which inflammation reduces muscle force remain incompletely understood. Recent work suggests that caspase 3 releases actin and myosin from the contractile protein lattice, so we postulated that infections may reduce skeletal muscle force by activating caspase 3. The present experiments were designed to test this hypothesis by determining 1) diaphragm caspase 3 activation in the diaphragm after endotoxin and 2) the effect of a broad-spectrum caspase inhibitor, Z-Val-Ala-Asp(OCH3)-fluoromethylketone (zVAD-fmk), and a selective caspase 3 inhibitor, N-acetyl-Asp-Glu-Val-Asp-al (DEVD-CHO), on endotoxin-induced diaphragm weakness. Caspase 3 activation was assessed by measuring caspase protein levels and by measuring cleavage of a fluorogenic substrate. Diaphragm force was measured in response to electrical stimulation (1-150 Hz). Caspase-mediated spectrin degradation was assessed by Western blotting. Parameters were compared in mice given saline, endotoxin (12 mg/kg ip), endotoxin plus zVAD-fmk (3 mg/kg iv), zVAD-fmk alone, or endotoxin plus DEVD-CHO (3 mg/kg iv). Endotoxin increased diaphragm active caspase 3 protein (P<0.003), increased caspase 3 activity (P<0.002), increased diaphragm spectrin degradation (P<0.001), and reduced diaphragm force (P<0.001). Administration of zVAD-fmk or DEVD-CHO prevented endotoxin-induced weakness (e.g., force in response to 150-Hz stimulation was 23.8+/-1.4, 12.1+/-1.3, 23.5+/-0.8, 22.7+/-1.3, and 24.4+/-0.8 N/cm2, respectively, for control, endotoxin, endotoxin plus zVAD-fmk, endotoxin plus DEVD-CHO, and zVAD-fmk alone treated groups, P<0.001). Caspase inhibitors also prevented spectrin degradation. In conclusion, endotoxin administration elicits significant diaphragm caspase 3 activation and caspase-mediated diaphragmatic weakness.

Actins↗

PubMed2000

Maximal bite force and surface EMG in patients with myasthenia gravis.

Masticatory muscle strength was quantified in patients with bulbar myasthenia gravis and compared with that of patients with ocular myasthenia gravis, patients in clinical remission (whether or not pharmacological) who previously suffered from bulbar myasthenia gravis, and healthy subjects. Maximal bite force and maximal activity of the masseter and temporalis muscles and of the submental muscle complex were measured. Bite force was decreased in the patients with bulbar myasthenia gravis, but was normal in the patients in the clinical remission group and in the ocular group. These findings were consistent with the results of electromyographic data. Although subjective reports of masticatory muscle weakness provide valuable information, quantitative measurements provide more information about the degree of muscle weakness of individual muscles. This is especially important for longitudinal evaluation of therapy in individual patients and for pharmacotherapeutic research.

Adult↗

PubMed2004

Proximal myopathy as an unusual presenting feature of celiac disease.

A 37-year-old woman presented with back pain, diffuse musculoskeletal pain, and muscle weakness without marked gastrointestinal symptoms. She complained of difficulty in walking and bilateral hip pain for the preceding year. Clinical examination revealed proximal muscle weakness especially in the lower extremities and a waddling gait pattern. Laboratory parameters and radiographic findings revealed the diagnosis of osteomalacia. The etiology of osteomalacia was investigated and a diagnosis of celiac disease was established. As osteomalacia symptoms may be the only presenting feature of celiac disease, it should be considered in the differential diagnosis of patients presenting with proximal muscle weakness and diffuse musculoskeletal pain.

Absorptiometry, Photon↗

PubMed2004

Polymyositis associated with urinary bladder cancer: an autopsy case.

A 56-year-old man suffered from muscle weakness with elevated serum creatine kinase. Under diagnosis of polymyositis, the patient was treated with corticosteroid, methotrexate and cyclosporin A. Eleven months after the first signs of muscle weakness, the patient suffered an abrupt onset of anuria and underwent hemodialysis. The patient died of respiratory insufficiency 14 months after the first signs of muscle weakness. Autopsy findings revealed associated urinary bladder cancer with histological indications of adenosquamous cell carcinoma, liver metastasis and cancerous lymphangitis of the lung.

Carcinoma, Adenosquamous↗

PubMed2006

A case of polymyositis complicated with myasthenic crisis.

We report a 62-year-old woman who suffered from polymyositis (PM) complicated with myasthenic crisis. Electromyography and muscle biopsy indicated a diagnosis of PM; however, respiratory failure due to respiratory muscle weakness was seen in spite of a normal serum creatine kinase (CK) level. The positive anti-acetylcholine receptor antibody led us to the diagnosis of myasthenic crisis. PM with respiratory muscle weakness is rare. We suggest that the possibility of other neurological disorder complications should be considered when PM patients have respiratory muscle weakness out of proportion to the serum CK level.

Autoantibodies↗

PubMed1998

Pain and disability in patients with osteoarthritis of hip or knee: the relationship with articular, kinesiological, and psychological characteristics.

OBJECTIVE: To determine to what extent articular, kinesiological, and psychological factors each contribute to pain and disability in patients with osteoarthritis (OA), after controlling for other factors. METHODS: Cross sectional study among 200 patients with OA of the hip or knee. Dependent variables include pain (visual analog scale), self-reported disability (questionnaire), and observed disability (performance of standardized tasks). Independent variables include joint degeneration (radiographs), muscle strength (dynamometer), range of joint motion (goniometer), pain coping (behavioral and cognitive strategies), and psychological well being (depression, anxiety, cheerfulness). Multiple regression analysis was used. RESULTS: Pain was found to be associated with muscle weakness and pain coping (p < 0.05). Disability was associated with muscle weakness, range of joint motion, pain, pain coping, and psychological well being (all p < 0.05). Both pain and disability were most strongly associated with kinesiological characteristics and pain coping. CONCLUSION: After controlling for the other characteristics, kinesiological and psychological characteristics in patients with OA are each associated with disability. The association with pain is less clear. Future research on mechanisms underlying these associations is warranted.

Adult↗

PubMed1999

Mechanisms of nasal tolerance induction in experimental autoimmune myasthenia gravis: identification of regulatory cells.

Autoantigen administration via nasal mucosal tissue can induce systemic tolerance more effectively than oral administration in a number of experimental autoimmune diseases, including Ab-mediated experimental autoimmune myasthenia gravis, a murine model of myasthenia gravis. The mechanisms underlying nasal tolerance induction are not clear. In this study, we show that nasal administration of acetylcholine receptor (AChR) in C57BL/6 mice, before immunizations with AChR in adjuvant, results in delayed onset and reduced muscle weakness compared with control mice. The delayed onset and reduced muscle weakness were associated with decreased AChR-specific lymphocyte proliferation and decreased levels of anti-AChR Abs of the IgG2a and IgG2b isotypes in serum. The clinical and immunological changes in the AChR-pretreated C57BL/6 wild-type (wt) mice were comparable with those observed in AChR-pretreated CD8-/- mice, indicating that CD8+ T cells were not required for the generation of nasal tolerance. AChR-pretreated wt and CD8-/- mice showed augmented TGF-beta and reduced IFN-gamma responses, whereas levels of IL-4 were unaltered. Splenocytes from AChR-pretreated wt and CD8-/- mice, but not from CD4-/- mice, suppressed AChR-specific lymphocyte proliferation. This suppression could be blocked by Abs against TGF-beta. Thus, our results demonstrate that the suppression induced in the present model is independent of CD8+ T cells and suggest the involvement of Ag-specific CD4+ Th3 cells producing TGF-beta.

Animals↗

PubMedDate not supplied

Music therapy as a treatment method for improving respiratory muscle strength in patients with advanced multiple sclerosis: a pilot study.

Respiratory muscle weakness, predominantly of the expiratory muscles, is characteristic of individuals with advanced multiple sclerosis and can result in difficulty in clearing secretions and repeated episodes of pneumonia. This pilot study evaluated the effectiveness of music therapy in strengthening respiratory muscles through an emphasis on diaphragmatic breathing and coordination of breath and speech. Twenty patients were randomly assigned to one of two groups: one that received music therapy or one that attended music appreciation sessions. Participants' inspiratory and expiratory muscle strength was measured by testing mouth pressure before and after the intervention. The experimental group showed some improvement in terms of expiratory muscle strength, in contrast to the control group, which showed deterioration. The results were not statistically significant, however. Patients in both groups exhibited considerable weakness in their expiratory muscles, and results for 79% of the participants were below 30% of the predicted values. Variability, a major confounding factor that resulted in reduced statistical power, led the investigators to suggest an intercenter collaboration to amass sufficient numbers of patients for a future study. Early manifestation of respiratory muscle weakness warrants inclusion of respiratory muscle testing in examination protocols and early intervention efforts.

Adult↗

PubMed2006

Possible therapeutic vaccines for canine myasthenia gravis: implications for the human disease and associated fatigue.

Myasthenia gravis (MG) is caused by T cell-dependent antibodies reactive with acetylcholine receptors. These autoreactive antibodies cause muscle weakness by interfering with neuromuscular transmission via removal of acetylcholine receptors from the neuromuscular junction as well as changing the architecture of the junction itself. Consequently, muscle fatigue is a debilitating aspect of MG often leading to more general feelings of tiredness not directly due to muscle weakness. We have previously described two peptides that are mimetics of antigen receptors on certain autoreactive T and B cells that are involved in MG. When used as vaccines in the rat model of MG, these peptides prevented and ameliorated disease and muscle fatigue by blunting acetylcholine receptor antibody responses. Such disease protection resulted from vaccine-induced anergizing antibodies against acetylcholine receptor-specific T and B cell antigen receptors. The present study prospectively evaluated the efficacy of these two vaccines in spontaneous acquired MG in pet dogs. When compared to historical controls that were prospectively studied, the vaccines increased the proportion of remitted dogs from 17 to 75%. In comparison to retrospectively studied historical controls that spontaneously remitted from MG, the vaccines accelerated the rate of decline in acetylcholine receptor antibody titers which resulted in a 3-fold decrease in the mean time to remission. These results are suggestive of a new type of targeted therapy that can drive autoimmune responses into long-term remission and possibly afford a means of determining whether correction of a physical cause of muscle weakness also corrects the perception of chronic, generalized fatigue.

Animals↗