PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Muscle Weakness”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31Linked to original sources

The physiology of inflammatory myopathies: an overview.

The idiopathic inflammatory myopathies (IIMs) encompass a group of muscle disorders of unknown origin and pathogenesis characterized by symmetrical, proximal muscle weakness and by inflammatory infiltrates in muscle tissue. The mechanisms behind the loss of muscle function are largely unknown. It is often anticipated that the muscle weakness is caused by the inflammatory cells. However, inflammatory infiltrates are not always present in the muscle tissue and the infiltrates sometimes have a patchy distribution, which makes it difficult to explain the generalized muscle weakness merely by infiltration of inflammatory cells. We investigated patients at different stages of myositis: early myositis without detectable inflammatory infiltrates, active myositis with pronounced inflammatory infiltrates and chronic myositis with persisting muscle weakness but without detectable inflammatory cells in muscle tissues. In these studies, a better correlation was observed between the clinical symptoms and involvement of the capillaries with expression of the cytokine interleukin (IL)-1alpha and by the presence of major histocompatibility complex (MHC) class I expression on muscle fibres. Whether these molecules could affect muscle function is not known. Using phosphorus P-31 magnetic resonance spectroscopy decreased values of adenosine triphosphate (ATP) and phosphocreatine (PCr) levels were observed at rest. These metabolic abnormalities were further accentuated by exercise and increased PCr levels correlated with improved clinical status. The underlying mechanisms responsible for these biochemical abnormalities have not been defined but could be related to a disturbed tissue oxygenation.

Cytokines↗

Effect of dietary supplementation with branched-chain amino acids on spontaneous motor activity and muscle function in beta,beta'-iminodipropionitrile-treated rats: a model for motorneuropathy.

Beta,beta'-iminodipropionitrile (IDPN)-induced muscle weakness in rats is a model for motorneuropathy diseases. The effects of oral administration of branched-chain amino acids on the progression of muscle weakness and muscle atrophy induced by the administration of IDPN in the drinking water, were investigated in this study. The spontaneous motor activity of the animals, as measured with a running wheel, slowly declined after IDPN administration, reaching a steady and low level at approximately week 15. Progressive muscle weakness and muscle atrophy were observed beginning at approximately 15 weeks after the initiation of administration of IDPN. Administration of branched-chain amino acids (BCAA) as a dietary supplement did not improve the lowered spontaneous motor activity seen in IDPN animals, but it did significantly improve measures of postural weakness and muscle strength [range of F values (2, 24) = 4.1-9.5, p < 0.05]. Plasma creatinine of the IDPN-treated rats was markedly elevated, and BCAA administration also significantly suppressed this elevation [F(2, 24) = 41.2, p < 0.05]. Moreover, although BCAA in plasma were elevated in the rats administered BCAA [range of F values (2, 21) = 25.7-29.7, p < 0.05], skeletal muscle showed no differences (at the p < 0.05 level) in the amounts of BCAA, whether or not BCAA were administered. These data suggest that the BCAA taken up in the skeletal muscle were utilized in the muscle of motorneuropathic rats and improved muscle function, such as energy metabolism, and that the BCAA treatment is one important therapeutic approach for retarding the progression of muscle weakness seen in certain neuromuscular disorders.

Amino Acids, Branched-Chain↗

History of standard scoring, notation, and summation of neuromuscular signs. A current survey and recommendation.

In this article, we trace the history of scoring, notation, and summation of the neuromuscular signs of muscle weakness and decrease of tendon reflexes and sensation. We recommend a standard system to promote consistency in the effort introduced by Mitchell and Lewis to "represent systems and force by their signs." The scoring of neuromuscular signs began with Mitchell and Lewis in the 19th century who used pluses, minuses, and N (for normal) to express the activity of muscle stretch reflexes. Henry Plummer introduced an ordinal scoring approach for muscle weakness, reflex decrease and increase, and sensation loss. In 1919, he and Walter Sheldon and Henry Woltman introduced standard pre-printed examination forms with written instructions for notation and scoring. Robert Lovett, a Boston orthopedist, scored weak muscles of poliomyelitis patients from 2 (mild weakness) to 6 (paralyzed), 1 being normal. Lovett's approach was used, after reversing the order of the grades and decreasing each grade by 1, by a Committee of the Medical Research Council for evaluating return of muscle weakness after nerve injury. Despite dissimilarity to existing reflex and sensation scores and uneven width of grades, this approach was widely adopted for use in neurologic practice. We introduced the Neuropathy Impairment Score using a combination of the Mitchell, Plummer, and Lovett approaches, summing all individual scores of a standard set of neuromuscular examinations. In a non-representative survey of 19 neuromuscular physicians from different countries, we find that there is a considerable variability in the approaches used for grading. Assuming that scoring is useful, we herein suggest (a) impairments should be scored separately from hyperfunction and (b) for the scoring of impairments (muscle weakness, reflex decrease, and sensation loss), the same ordinal scoring approach should be used with 0 as normal and 1, 2, ... representing increasing impairment based on the judgment of percentage abnormality with corrections made for age, sex, physical fitness, and physical characteristics.

Data Collection↗

Use of etanercept in the treatment of dermatomyositis: a case series.

OBJECTIVE: To evaluate the efficacy of etanercept, a recombinant human soluble fusion protein of tumor necrosis factor-alpha (TNF-alpha) type II receptor and IgG1, in patients with adult dermatomyositis (DM). METHODS: Five patients with active DM were studied. All patients reported muscle weakness and had elevated muscle enzymes creatine kinase and lactate dehydrogenase. Because of lack of response to steroid and cytotoxic therapy, etanercept was given at a dose of 25 mg subcutaneously twice a week for at least 3 months. RESULTS: All patients experienced an exacerbation of disease, with increase of muscle weakness, elevation of muscle enzyme levels, and unchanged rash. Treatment with etanercept was stopped. After receiving a combination of methotrexate (MTX) and azathioprine, disease manifestations improved in all patients. CONCLUSIONS: In our case series, TNF-alpha inhibition by etanercept was not effective, suggesting that a broad immunosuppressive therapy is needed to treat DM.

Adult↗

Hypernatremic myopathy.

We describe a 21-year-old man presenting with proximal muscle weakness associated with hypernatremia. His manifestations other than muscle weakness included dry skin, loss of axillary and pubic hair, decreased libido and loss of thirst sensation. His serum sodium level was elevated to 169-171 mEq./l but all other electrolytes were normal. In addition, serum CK was elevated and an EMG study showed myogenic changes. Endocrinological studies revealed hypothalamic hypopituitarism, while MRI revealed a suprasellar mass. A partial correction of hypernatremia led to an immediate recovery of the muscle weakness as well as a normalization of both the serum CK level and EMG findings, suggesting a direct association between the muscle weakness and hypernatremia. The phosphocreatine/inorganic phosphorus (PCr/Pi) ratios in the resting calf muscle, obtained using 31P magnetic resonance spectroscopy (MRS), were very low during the state of muscle weakness, while they returned to nearly normal values after clinical improvement, suggesting that the muscle weakness in hypernatremic state was caused by a depletion of the intramuscular energy stores, probably due to an overworking Na-K pump to correct the intracellular electrolyte imbalance.

Adult↗

Signs and symptoms of Duchenne muscular dystrophy and Becker muscular dystrophy among carriers in The Netherlands: a cohort study.

BACKGROUND: Carriers of Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) may show muscle weakness or dilated cardiomyopathy. Studies focusing on skeletal-muscle involvement were done before DNA analysis was possible. We undertook a cross-sectional study in a population of definite carriers to estimate the proportion and to assess the clinical profile of carriers with symptoms. We also assessed a possible correlation between genotype and phenotype. METHODS: Carriers of DMD and BMD, aged 18-60 years, were traced through the files of the central register kept at the Department of Human Genetics in Leiden, Netherlands. For each carrier who agreed to participate a medical history was taken, and muscle-strength assessment by hand-held dynamometry and manual muscle testing and cardiological assessment were done. FINDINGS: 129 carriers of muscular dystrophy (85 DMD, 44 BMD) participated in the study. In 90 women from 52 (70%) families, 37 different mutations were found. 28 (22%) women had symptoms. 22 (17%) had muscle weakness, varying from mild to moderately severe. Muscle weakness was found in carriers of DMD and BMD, but dilated cardiomyopathy was found only in seven (8%) carriers of DMD, of whom one had concomitant muscle weakness. There was an unexpectedly high proportion of left-ventricle dilation (18%). No genotype-phenotype correlation was found. INTERPRETATION: Clinical manifestation of muscle weakness, dilated cardiomyopathy, or both can be found in about a fifth of carriers of DMD and BMD. If left-ventricle dilation is taken into account, the proportion of carriers with symptoms is even higher, amounting to 40%.

Adolescent↗

A case of McLeod syndrome with unusually severe myopathy.

A 51-year-old man developed weakness and muscle atrophy in the legs at the age of 41, later followed by choreiform involuntary movements. Neurological and laboratory examinations revealed severe muscle weakness and atrophy, and areflexia in all the extremities, acanthocytosis and an elevated serum creatine kinase level. Together with these findings, the weak expression of Kell blood group antigens and the absence of the Kx antigen led to a definite diagnosis of McLeod syndrome for his condition. Brain magnetic resonance imaging revealed marked atrophy of the head of the caudate nuclei. Although immunocytochemical analysis of dystrophin in muscle specimens from our patient revealed normal staining, we found prominent fiber size variability, central nuclei, and connective tissue proliferation as well as necrotic and regenerating fibers, which are as a whole compatible with the myopathology of muscular dystrophy. Moreover, muscle computerized tomography of the lower extremities revealed the 'selectivity pattern' characteristically reported in muscular dystrophies including Duchenne type muscular dystrophy. The muscular symptoms and pathology in McLeod syndrome have been reported to be mild, but the present case clearly shows that the muscular features in this condition may be much more severe than previously thought.

Acanthocytes↗

Neither changes in phosphorus metabolite levels nor myosin isoforms can explain the weakness in aged mouse muscle.

1. The contractile force, phosphorus metabolite levels, intracellular pH and myosin isoforms were compared in isolated soleus and extensor digitorum longus (EDL) muscles from young (6 month old) and aged (28 month old) mice, at 23 degrees C. 2. The isometric force per unit cross-sectional area was significantly lower by 21 +/- 5% in soleus muscles from aged mice compared to those from young mice (mean +/- S.E.M., n = 11 and 9 respectively). 3. The EDL muscle contained twice as much total creatine and phosphocreatine as the soleus, 1.7 times as much ATP, and 0.4 times the inorganic phosphate (Pi) per unit weight. The intracellular pH and free ADP levels were not significantly different between these muscle types. 4. There was no significant difference in resting metabolite levels between young and old EDL or soleus despite the difference in mechanical strength. 5. Examination of the expression of myosin isoforms by non-denaturing gel electrophoresis has shown that the percentage of each isoform does not change with respect to age; thus, if there is an atrophic process occurring, it is not fibre type specific. 6. We have determined that neither the Pi levels nor the intracellular pH can explain the differences seen in muscle strength with age. There is also no correlation between muscle weakness and any of the other metabolites responsible for energy transduction (phosphocreatine, ATP or ADP).

Adenosine Diphosphate↗

Calcitriol-mediated hypercalcaemia and increased interleukins in a patient with sarcoid myopathy.

In this report we describe a patient with Sjögren's syndrome (SS) and calcitriol-mediated hypercalcaemia. Initially, there was no clinical evidence of sarcoidosis. The patient had hypercalcaemia associated with increased calcitriol serum levels; circulating interleukin-6 and tumour necrosis factor alpha levels were also elevated. At the beginning, therapy with clodronate was effective in decreasing the serum calcium levels. However, the serum calcitriol decreased only after chloroquine treatment was added. After 2 years of therapy, the patient developed progressive and extensive muscle weakness. A muscle biopsy revealed a very prominent non-caseating granulomatous myopathy. Corticosteroid therapy was then instituted. Although both chloroquine and corticosteroid therapy were associated with decreased serum interleukin and calcitriol levels, only corticosteroid therapy was effective in treating the sarcoid myopathy. The role of cytokines in calcitriol mediated hypercalcaemia is discussed.

Antirheumatic Agents↗

Electromyogram-controlled functional electrical stimulation for treatment of the paralyzed upper extremity.

Spinal cord lesions at level C5 to C6 lead to loss of hand functions and lesions at C4 to additional deficits of arm functionality. The presented dual channel surface stimulator with dual channel electromyogram (EMG) measurement was developed to investigate control strategies for an EMG-controlled implantable stimulation system and serves in addition as a therapy device for patients with partial innervation but weak muscle force. Four different control strategies for stimulation amplitude are available. The amplitude can be preset manually or can follow the preprocessed EMG signals proportionally. The shoulder control program allows proportional control of both stimulation channels with one EMG channel while the second EMG channel serves as the channel selector. Finally, a special feedback training program triggers a stimulation burst when EMG activity is detected. During a 2 year patient study, 18 patients from 2 hospitals and 1 rehabilitation center performed the feedback training. Almost all patients obtained an improvement of functionality. Apart from muscle strengthening, the feedback effect led to an improvement of proprioception and supported relearning of motions. For the documentation of the training status, functional muscle test (British Medical Research Council) and measurements of power, angle, torque, muscle fatigue, and EMG were performed. Obviously, EMG triggered stimulation provides several advantages compared to conventional passive electrical stimulation.

Arm↗

[Dermatomyositis in childhood].

AIM: The aim of this study is to review the presenting signs and symptoms, laboratory findings and therapeutic regimens of juvenile dermatomyositis in a tertiary hospital. METHODS: We reviewed retrospectively the available medical records of patients who met the clinicopathologic criteria of Bohan and Peter for definite juvenile dermatomyositis. They were followed between 1986 and july 1999 at the pediatric rheumatology section at our institution. RESULTS: The patient population included 3 male and 6 female patients. The mean age at diagnosis was 7 years. Clinical features demanding medical attention at the hospital were: muscle weakness and pain, with associated general symptoms in 4 cases; isolated muscle weakness in 2 cases; muscle weakness associated to general symptoms in 1 case; and monoarthritis in another case. One patient presented initially only with cutaneous rash. Three patients developed calcinosis. Serum CPK and LDH levels were elevated in 8 patients, aldolase in 7 and aminotransferases in 6. Autoantibodies were undetectable in all the patients. Electomyography demonstrated myopatic or mixed pattern in the 5 patients it was practiced. Muscle biopsy showed features of inflammatory myopathy in all the cases. Seven patients were treated exclusively with steroids and 2 patients with steroids, methotrexate and intravenous gammaglobuline. Actually, 6 patients are asymptomatic, 2 have mild muscle weakness, and 1 has died. CONCLUSIONS: The results of our review agree with other series reported. Juvenile dermatomyositis suspicious should be made upon muscle weakness and general symptoms. Treatment with steroids should be started promptly.

Adolescent↗

A systematic review of adult-onset clinically amyopathic dermatomyositis (dermatomyositis siné myositis): a missing link within the spectrum of the idiopathic inflammatory myopathies.

OBJECTIVE: Classical dermatomyositis (CDM) patients display the hallmark cutaneous manifestations of dermatomyositis (DM), proximal muscle weakness, and laboratory evidence of myositis. The epidemiology and management of both adult-onset and juvenile-onset CDM has been well characterized. However, the clinical significance of the hallmark inflammatory cutaneous manifestations of DM occurring in individuals who have no clinically significant muscle weakness and normal muscle enzymes for prolonged periods of time (ie, 6 months or longer) has not been clear. The term amyopathic DM (ADM) (synonymous with DM siné myositis) has been proposed to draw attention to such individuals. A related form of DM, "hypomyopathic DM" [HDM], is the presence of DM skin disease for 6 months or longer in individuals who have no muscle weakness but who are found to have some evidence of muscle inflammation upon testing (muscle enzyme levels, electromyogram, muscle biopsy, muscle magnetic resonance imaging [MRI]). Clinically amyopathic DM (CADM) is a designation that has been proposed for patients having either ADM or HDM. The clinically amyopathic component of this designation was coined to emphasize the fact that the only clinical problem being experienced by these patients at the time of diagnosis is their DM skin disease. Our personal experience suggests that the CADM subphenotype might be more prevalent in adults than has been thought previously. To test this hypothesis and address questions relating to the optimal management and prognosis of such patients, we have systematically reviewed the published literature in this area. METHODS: We carried out a systematic review of the published literature on adult-onset CADM as defined in Table 1 through May 1, 2004. RESULTS: We identified 291 adult-onset CADM cases (18 years or older) reported from over 19 countries. The average duration of DM skin disease was 3.74 years (range, 6 months [by definition] to > 20 years), and 73% were female. Among 37 patients with HDM who were identified, the average duration of disease was 5.4 years, and none had developed clinically significant weakness at the time of the reports. Thirty-seven of the reported CADM patients developed muscle weakness greater than 6 months after onset of their skin disease (15 months to 6 years). For the sake of this discussion, such patients have been analyzed under the designation of "CADM --> CDM." Somewhat surprisingly, 36/291 (13%) of the identified published CADM patients developed interstitial lung disease. Incidental to our review, we also identified 10 published cases of individuals having DM skin disease and interstitial lung disease without muscle weakness, 7 of whom died from interstitial lung disease less than 6 months after onset of their DM skin disease (the term pre-myopathic DM coined by others has been used here to refer to such patients). In addition, an associated internal malignancy was found in 41/291 (14%) of the identified CADM cases. A positive antinuclear antibody was reported in 63% and myositis-specific autoantibodies (eg, Jo-1, Mi-2) in only 3.5% of the reported CADM patients in which such data were available. CONCLUSIONS: The results of this analysis suggests that the CADM subphenotype is more common than has been thought previously and that such patients may comprise a relatively high proportion of DM patients followed by dermatologists. Some CADM patients also have been observed to develop overt proximal muscle weakness years after onset of their DM skin disease. In addition, CADM patients appear to be at risk of developing the same potentially fatal disease associations/complications for which CDM patients are at risk (eg, interstitial lung disease and internal malignancy). Population-based studies of the epidemiology and optimal management of CADM patients, including efforts to identify risk factors associated with potentially fatal outcomes such as late-onset muscle weakness, interstitial lung disease, and malignancy, are needed. As an incidental finding to this literature review, we also identified a small number of reported cases of often-fatal interstitial lung disease occurring shortly after the onset of DM skin disease (< 6 months) in the complete absence of muscle weakness. This subphenotype, referred to as "pre-myopathic DM," is one with which dermatologists should be aware as early diagnosis and aggressive management can be lifesaving.

Adult↗

Chronicity of neurological features in ciguatera fish poisoning.

A 43-year-old woman complained of colicky abdominal pain, followed by numbness, myalgias, and muscle weakness in the four limbs after eating a grouper (Epinepheius spp.). She presented to our hospital 36 hours later with increased myalgias, muscle weakness, and malaise. On examination, the muscle power and sensation in her four limbs appeared to be normal. She was given an intravenous infusion of mannitol 20% (200 ml over 1 hour) and an intramuscular injection of diclofenac (75 mg). Her myalgias then improved and she was discharged. She presented to our hospital again 1 week later with poor appetite, malaise, numbness of the four limbs, and increased muscle weakness. On examination, the muscle weakness was more marked in the lower limbs (4+/5) than in the upper limbs (5-/5) and proximally than distally. She also had some difficulty in getting up from a squatting position. She was given another intravenous infusion of mannitol 20% (200 ml over 1 hour), following which there was subjectively slight improvement in her muscle weakness. Herplasma creatine phosphokinase level was normal. Electromyography performed 4 weeks later revealed no abnormalities. When she was reviewed 45 days after the consumption of the grouper, her muscle weakness and malaise had improved considerably. She could then stand up from a squatting position. However, mild impairment of finger grip was still present. Chronicity of neurological features in other reported cases (e.g., chronic fatigue, relapse of symptoms after exposure to ciguateric fish or alcohol, and peripheral neuropathy) may also indicate a lengthy persistence of ciguatoxins in the body.

Adult↗

The 1999 Moyer award. Burn injury induces skeletal muscle apoptosis and the activation of caspase pathways in rats.

Burn injury induces many metabolic disorders, including altered protein kinetics with muscle weakness. The skeletal muscle weakness that occurs as a result of the loss of muscle mass causes hypoventilation and dependence on respirators, a condition that increases morbidity and mortality. The presence or absence of apoptosis in muscle, which can be a cause of the loss of muscle mass, was studied in rats after they had received scald burns to 40% of their body surface areas. The potential pro-apoptotic pathways that were activated were also examined. The burn injury produced did not directly destroy the muscle beneath; muscles just beneath the burned surface showed dramatic apoptotic changes according to assessments with the cell death enzyme-linked immunosorbent assay and in situ TdT-mediated dUTP-X nick-end labeling staining. The extent of apoptosis reached a peak on postburn days 3 and 7. Of note is that apoptosis was also confirmed in muscles at sites distant from the burn injury (eg, tibialis anterior) on both postburn days 3 and 7, a condition that is suggestive of the systemic effects of pro-apoptotic factors. To show that heat itself causes the initiation of the pro-apoptotic signaling, muscle-derived C2C12 cells were subjected to heat treatment at 55 degrees C. Ceramide, a key apoptotic second messenger, was observed to increase in the caveolae fraction but not in non-caveolae fraction of these muscle cells. In muscle tissue from burned rats, stress-activated protein kinase (a downstream-signaling kinase of ceramide) was activated soon after burn injury; this finding is consistent with the hypothesis that ceramide plays a role in burn-induced apoptosis. Caspase-1, -3, and -9, important final apoptotic enzymes involved with the downstream signaling of stress-activated protein kinase, were also activated after burn injury in muscle tissue from burned rats. These findings confirm the hypothesis that apoptosis occurs in skeletal muscle and that major apoptotic pathways are activated after a burn injury. Further characterization of these apoptotic signaling cascades may provide new therapeutic targets for the prevention of burn-induced muscle wasting.

Animals↗

[A patient with limb-girdle type myasthenia gravis and atopic dermatitis, both of which improved after thymectomy].

We herein report a patient with myasthenia gravis (MG) and atopic dermatitis (AD). Heretofore, there have been no reports of patients with MG and AD. Nine years ago, a 25-year-old man noted muscle weakness of upper and lower extremities on physical labor, and the muscle weakness was gradually exacerbated. Two years ago, he noted acute skin eczema with itching on his hands and feet. Neurological examination revealed mild left ptosis, facial muscle weakness and proximal muscle weakness of upper and lower extremities, but no diplopia, ophthalmoplegia or dysphagia. Although anti-nicotinic acetylcholine receptor antibody was negative, edrophonium test was positive and 54% waning in the thenar muscles was observed on Harvey-Masland test. Thus, he was diagnosed as limb-girdle type MG. IgE level in his serum elevated (1,818 U/ml). After thymectomy, the muscle weakness markedly improved as well as waning in the thenar muscles (11%). Simultaneously, AD markedly improved and serum IgE level was decreased (1,245 U/ml). Thus, MG and AD in this case may be derived from some common immunological aberrancy in the thymus.

Adult↗

[Non hypertrophic amyloid myopathy with muscular inflammation in plasma cell dyscrasia].

The case of a 41 year old woman with amyloid myopathy is reported. Clinical involvement consisted of limb girdle muscle weakness, mild scapular muscle atrophy and dysphagia. In contrast with the published cases, abnormal firmness, pseudohypertrophy of the musculature and macroglossia were absent. Muscle biopsy showed endo- and perimysial amyloid deposits but also inflammatory infiltrates. Inflammatory cells typing was studied by immunocytochemical methods and revealed a predominant T-helper cell infiltration. Free kappa light chains were present in serum and urine. Serum immunoglobulin levels were reduced. Bone marrow examination revealed mild plasmocytosis without abnormal cells. Immunofluorescence and immunoperoxidase techniques for identification of the type of amyloid fibrils showed positivity with antisera to kappa light chains. A 4-year follow-up revealed a progressive worsening of muscle weakness despite immunosuppressive treatment. No malignant plasmocytosis occurred. The unusual inflammatory muscle infiltration observed in this case may suggest an associated polymyositis.

Adult↗

Long-term outcome in children with Guillain-Barré syndrome.

OBJECTIVE: To determine the long-term sequelae and early predictors of sequelae for children with Guillain-Barré syndrome (GBS) after the introduction of intravenous gammaglobulin (IVIG). Study design A cross-sectional case series of children with GBS, at least 2 years after recovery, was performed. Manual muscle strength testing was done on 34 muscle groups. The functional independence measure was used to assess function. A chart review was completed, identifying acute factors that may predict long-term sequelae. RESULTS: Forty-seven children with GBS were identified, of whom 30 received IVIG. Persisting long-term muscle weakness with at least one muscle group at a grade 6 level (muscle moves the joint against gravity but only minimal resistance to an applied force) was found in 23% of cases. Each patient had a perfect score on the functional independence measure. Long-term muscle weakness was predicted by young age (P =.03) and a rapid progression to maximal weakness (P =.03). CONCLUSIONS: Despite the introduction of IVIG, 23% of children with GBS had evidence of long-term mild muscle weakness, with minimal impact on function. Young age and a rapid progression during the acute GBS period predicted long-term sequelae.

Activities of Daily Living↗

Increased expression of interleukin 1alpha and MHC class I in muscle tissue of patients with chronic, inactive polymyositis and dermatomyositis.

OBJECTIVE: To investigate if there is a molecular correlate in muscle tissue to the persisting decreased muscle function in patients with chronic, inactive polymyositis (PM) and dermatomyositis (DM). METHODS: Muscle function was assessed using a muscle function index of myositis. To assess disease activity both histopathological investigation of muscle biopsies and magnetic resonance imaging (MRI) scans of the thigh muscles were performed. Inactive chronic disease was defined as persisting muscle weakness and absence of inflammatory infiltrates in muscle biopsy and absence of signs of inflammation on MRI. Expression of interleukin 1alpha (IL-1alpha), IL-1beta,, adhesion molecules, and MHC class I molecules in muscle tissue was investigated with immunohistochemistry. RESULTS: Muscle weakness was confirmed by a reduction of muscle function score. No signs of inflammation typical for myositis were observed. The most striking finding in our study was the strong expression of IL-1alpha and MHC class I molecules in muscle tissue from patients with inactive chronic PM and DM. Increased IL-1alpha expression was evident in capillaries and increased MHC class I expression was detected in muscle fiber membranes. CONCLUSION: IL-1alpha and MHC class I molecules may have an importance in the pathogenesis of the chronic muscle weakness and fatigue in patients with PM and DM.

Adult↗