The role of exercise in the rehabilitation of idiopathic inflammatory myopathies

Effect of Exercise on β-Endorphin and Its Receptors in Myasthenia Gravis Patients

This is a prospective observational study evaluating the change in β-endorphin (BE) and its receptors following exercise in patients with myasthenia gravis (MG) and their association with clinical improvement. Fifteen patients with mild to moderate MG, aged 16-70 years, who were able to do 6-Minute Walk Test (6-MWT) and had MG Quality of Life-15 (MGQoL-15) ≤ 45 without any contraindication for exercise were included. The patients walked 30 min daily for 3 months. The primary outcome at 3 months was > 50% improvement in MGQoL-15 from the baseline, and the secondary outcomes were MG Activities of Daily Living (MGADL), Hospital Anxiety and Depression Scale (HADS), number of steps, and distance covered on 6-MWT and adverse events. Plasma BE level, μ-opioid receptor (MOR), and δ-opioid receptor (DOR) were measured on admission and at 1 and 3 months. Twelve age- and gender-matched healthy controls who were not on regular exercise were included for comparison of BE, MOR, and DOR levels. Plasma BE level (P = 0.007) and DOR expression (P = 0.001) were lower in MG patients compared to the healthy controls. After 3 months of exercise, 6 patients improved. Plasma BE, MOR, and DOR levels increased in the first and decreased in the third month. MGQoL-15 (P < 0.001), HADS (P < 0.0001), number of steps (P < 0.007), distance (P = 0.030), and MGADL (P < 0.001) significantly improved compared to baseline. At 3 months, MGQoL-15 was associated with HADS score (P = 0.001), reduced depression (P = 0.013), MGADL (P = 0.035), and distance travelled on the 6-WMW test (P = 0.050). The improvement in depression was associated with higher BE level.

New insights into the treatment of myositis

The myositis syndromes include polymyositis, dermatomyositis (DM), necrotizing myopathy, inclusion body myositis (IBM), antisynthetase syndrome and overlap syndromes with myositis. These syndromes mostly occur in middle-aged patients, while juvenile DM occurs in children and adolescents. Patients mostly show a subacute weakness and myalgia in the upper and lower limbs, the diagnosis is based upon these clinical findings in combination with muscle biopsy results and specific serum autoantibodies. In recent years, research achieved a better understanding about the molecular mechanism underlying the myositis syndromes, as well as disease progress and extramuscular organ manifestations, such as interstitial lung disease and association with neoplasias. Treatment mainly consists of glucocorticosteroids and immunosuppressants. IBM is usually refractory to treatments. This review provides an overview of the current standards of treatment and new treatment options like monoclonal antibodies and new molecular therapies and their first results from clinical trials.

Guidelines on dermatomyositis--excerpt from the interdisciplinary S2k guidelines on myositis syndromes by the German Society of Neurology

The present guidelines on dermatomyositis (DM) represent an excerpt from the interdisciplinary S2k guidelines on myositis syndromes of the German Society of Neurology (available at www.awmf.org). The cardinal symptom of myositis in DM is symmetrical proximal muscle weakness. Elevated creatine kinase, CRP or ESR as well as electromyography and muscle biopsy also provide important diagnostic clues. Pharyngeal, respiratory, cardiac, and neck muscles may also be affected. Given that approximately 30% of patients also develop interstitial lung disease, pulmonary function tests should be part of the diagnostic workup. Although the cutaneous manifestations in DM are variable, taken together, they represent a characteristic and crucial diagnostic criterion for DM. Approximately 5-20% of individuals exhibit typical skin lesions without any clinically manifest muscle involvement (amyopathic DM). About 30% of adult DM cases are associated with a malignancy. This fact, however, should not delay the treatment of severe myositis. Corticosteroids are the therapy of choice in myositis (1-2 mg/kg). Additional immunosuppressive therapy is frequently required (azathioprine, for children methotrexate). In case of insufficient therapeutic response, the use of intravenous immunoglobulins is justified. The benefit of rituximab has not been conclusively ascertained yet. Acute therapeutic management is usually followed by low-dose maintenance therapy for one to three years. Skin lesions do not always respond sufficiently to myositis therapy. Effective treatment for such cases consists of topical corticosteroids and sometimes also calcineurin inhibitors. Systemic therapies shown to be effective include antimalarial agents (also in combination), methotrexate, and corticosteroids. Intravenous immunoglobulins or rituximab may also be helpful. UV protection is an important prophylactic measure.

Clinical heterogeneity and outcomes of antisynthetase syndrome

The autoimmune connective tissue disease antisynthetase syndrome (ASS) is an inflammatory myopathy associated with myositis-specific autoantibodies, e.g. anti-tRNA-synthetase antibodies (ASA). Since 1976 eight different ASA have been rigorously identified, of which anti-hystidyl-tRNA synthetase (anti-Jo1) is the most prevalent. Other phenotype features of ASS include interstitial lung disease (ILD), Raynaud's phenomenon, polyarthritis, fever, and mechanic's hands. The clinical presentation of ASS varies greatly, as does the severity of involvement of different organs-both among patients and/or over the course of the disease. ILD has been associated with poor outcomes, but in general the heterogeneity of ASS prevents identification of robust prognosis indicators. Early identification of patients requiring aggressive immunosuppressive treatment is very challenging, and there are very few prospective trials available to help match treatment management to ASS clinical characteristics. This review will focus on the biological, clinical, functional, and morphological features of ASS associated with patient outcome. Our objective is to use compiled data on these subjects to discuss the usefulness of patient stratification in developing future prospective therapeutic trials.

Exercise in neuromuscular disease

In this review, we present an overview of the role of exercise in neuromuscular disease (NMD). We demonstrate that despite the different pathologies in NMDs, exercise is beneficial, whether aerobic/endurance or strength/resistive training, and we explore whether this benefit has a similar mechanism to that of healthy subjects. We discuss further areas for study, incorporating imaginative and novel approaches to training and its assessment in NMD. We conclude by suggesting ways to improve future trials by avoiding previous methodological flaws and drawbacks in this field.

Idiopathic inflammatory myopathies

Inflammatory myopathies are chronic, immune-mediated diseases characterised by progressive proximal muscle weakness. They encompass a variety of syndromes with protean manifestations. The diagnosis is based on Bohan and Peter's classification criteria, which nowadays seem to be obsolete. Our increasing knowledge about the risk factors, genetic susceptibility and immunological pathways in the disease mechanism leads to the establishment of a new, immunogenetically and serologically validated diagnostic criteria system. The treatment of idiopathic inflammatory myopathy is also a complex task requiring much experience. The aims of therapy are to increase muscle strength, prevent the development of contractures and manage the systemic manifestations of the disease. The most important one is the early detection of diseases and patients' immunological control in special centres. Using the basis therapeutic drugs temporary or permanent remission can be achieved, which improves patientsG' quality of life and functional ability. Rehabilitation and physiotherapy in the remission period may significantly improve the outcome of patients with functional disorders. The introduction of new biological therapies further allows us to control the myositis patients' state more effectively. The aim of this review is to summarise our knowledge about clinical symptoms, pathomechanism, as well as genetic, serologic and environmental risk factors. We would also like to present the way to diagnosis and the latest research about diagnostic criteria system, proposed outcome measures and therapeutic possibilities.

Exercise in neuromuscular diseases

This article reviews the current knowledge regarding the benefits and contraindications of exercise on individuals with neuromuscular diseases (NMDs). Specific exercise prescriptions for individuals with NMDs do not exist because the evidence base is limited. Understanding the effect of exercise on individuals with NMDs requires the implementation of a series of multicenter, randomized controlled trials that are sufficiently powered and use reliable and valid outcome measures to assess the effect of exercise interventions-a major effort for each NMD. In addition to traditional measures of exercise efficacy, outcome variables should include measures of functional status and health-related quality of life.

The effects of lingual intervention in a patient with inclusion body myositis and Sjögren's syndrome: a longitudinal case study

OBJECTIVE

To report the 5-year course of a patient's swallowing disorder in the context of progressive neuromuscular disease and the effectiveness of a lingual strengthening treatment program.

DESIGN

This is a case report that describes a lingual treatment protocol that was repeated 3 times over a 5-year period with and without maintenance periods.

SETTING

The study was completed in 2 settings-an outpatient swallowing clinic at an acute care hospital and the patient's home.

PARTICIPANT

The subject was a 77-year-old woman who was diagnosed with inclusion body myositis and Sjögren's syndrome.

INTERVENTION

The patient participated in an intensive 8-week lingual strengthening protocol 3 times (at years 1, 4, and 5) and a subsequent maintenance program twice (at years 4 and 5).

MAIN OUTCOME MEASURES

Three outcome measures were collected during the study: (1) lingual manometric pressures at the anterior and posterior tongue, measured by using a lingual manometric device, (2) airway invasion measured by using an 8-point Penetration-Aspiration Scale, and (3) clearance of the bolus measured by using a 3-point residue scale.

RESULTS

Isometric lingual strengthening was effective in maintaining posterior tongue lingual pressure and Penetration-Aspiration Scale scores during the treatment periods. Residue scale scores did not significantly change during treatment.

CONCLUSIONS

We conclude that, in this patient, lingual strengthening slowed the progression of disease-related lingual strength loss and extended functional swallowing performance. Thus, this type of intervention may hold promise as an effective swallowing treatment option for patients with neurodegenerative inflammatory diseases such as inclusion body myositis and Sjögren's syndrome.

New therapeutic approaches for polymyositis and dermatomyositis

Inflammatory myopathies are chronic, immune-mediated diseases characterized with progressive proximal muscle weakness. They encompass a variety of syndromes with protean manifestations. The aims of therapy are to increase muscle strength, prevent the development of contractures, and to manage the systemic manifestations of the disease. This is a complex treatment which requires routine and wide knowledge. The most important task is to recognize the disease and guide the patient to immunologic center. Although the first line of therapy continues to include corticosteroids, there are a multitude of agents available for treating patients with myositis. There are several different immunosuppressive agents which may be applied alone or in combination with each other, as well as an increasing number of novel and exciting biologic agents targeting molecules participating in the pathogenesis of inflammatory myopathy. Physiotherapy and rehabilitation in the remission period may significantly improve the functional outcome of patients with these disorders. Orv. Hetil., 2011, 152, 1552–1559.

Expression of human amyloid precursor protein in the skeletal muscles of Drosophila results in age- and activity-dependent muscle weakness

BACKGROUND

One of the hallmarks of Alzheimer's disease, and several other degenerative disorders such as Inclusion Body Myositis, is the abnormal accumulation of amyloid precursor protein (APP) and its proteolytic amyloid peptides. To better understand the pathological consequences of inappropriate APP expression on developing tissues, we generated transgenic flies that express wild-type human APP in the skeletal muscles, and then performed anatomical, electrophysiological, and behavioral analysis of the adults.

RESULTS

We observed that neither muscle development nor animal longevity was compromised in these transgenic animals. However, human APP expressing adults developed age-dependent defects in both climbing and flying. We could advance or retard the onset of symptoms by rearing animals in vials with different surface properties, suggesting that human APP expression-mediated behavioral defects are influenced by muscle activity. Muscles from transgenic animals did not display protein aggregates or structural abnormalities at the light or transmission electron microscopic levels. In agreement with genetic studies performed with developing mammalian myoblasts, we observed that co-expression of the ubiquitin E3 ligase Parkin could ameliorate human APP-induced defects.

CONCLUSIONS

These data suggest that: 1) ectopic expression of human APP in fruit flies leads to age- and activity-dependent behavioral defects without overt changes to muscle development or structure; 2) environmental influences can greatly alter the phenotypic consequences of human APP toxicity; and 3) genetic modifiers of APP-induced pathology can be identified and analyzed in this model.

Rehabilitation management of neuromuscular disease: the role of exercise training

This paper summarizes the current state of knowledge regarding exercise and neuromuscular diseases/disorders (NMDs) and reviews salient studies in the literature. Unfortunately, there is inadequate evidence in much of the NMDs to make specific recommendations regarding exercise prescriptions. This review focuses on the role of exercise in a few of the specific NMDs where most research has taken place and recommends future research directions.

Improvement in aerobic capacity after an exercise program in sporadic inclusion body myositis

OBJECTIVES

The study aimed to investigate the effects of a combined functional and aerobic exercise program on aerobic capacity, muscle strength, and functional mobility in a group of patients with sporadic inclusion body myositis (IBM).

METHODS

Aerobic capacity, muscle strength, and functional capacity assessments were conducted on 7 participants with sporadic IBM before and after a 12-week exercise program, which included resistance exercises and aerobic stationary cycling 3 times per week on alternative days.

RESULTS

Aerobic capacity of the group increased significantly by 38%, and significant strength improvements were observed in 4 of the muscle groups tested (P < 0.05). The exercise program was well tolerated, and there was no significant change in the serum creatine kinase level after the exercise period.

CONCLUSIONS

An aerobic exercise program can be safely tolerated by patients with sporadic IBM and can improve aerobic capacity and muscle strength when combined with resistance training. These findings indicate that aerobic and functional muscle strengthening exercise should be considered in the management of patients with IBM.

Effect of physical training on the proportion of slow-twitch type I muscle fibers, a novel nonimmune-mediated mechanism for muscle impairment in polymyositis or dermatomyositis

OBJECTIVE

To compare muscle fiber type composition and muscle fiber area in patients with chronic polymyositis or dermatomyositis and healthy controls, and to determine whether physical training for 12 weeks could alter these muscle characteristics.

METHODS

Muscle fiber type composition and muscle fiber area were investigated by biochemical and immunohistochemistry techniques in repeated muscle biopsy samples obtained from 9 patients with chronic myositis before and after a 12-week exercise program and in healthy controls. Muscle performance was evaluated by the Functional Index (FI) in myositis and by the Short Form 36 (SF-36) quality of life instrument.

RESULTS

Before exercise, the proportion of type I fibers was lower (mean +/- SD 32% +/- 10%) and the proportion of type IIC fibers was higher (3% +/- 3%) in patients compared with healthy controls. After exercise, percentage of type I fiber increased to 42% +/- 13% (P < 0.05), and type IIC decreased to 1% +/- 1%. An exercise-induced 20% increase of the mean fiber area was also observed. The functional capacity measured by the FI in myositis and the physical functioning subscale of the SF-36 increased significantly. Improved physical functioning was positively correlated with the proportion of type I fibers (r = 0.88, P < 0.01) and type II muscle fiber area (r = 0.70, P < 0.05).

CONCLUSION

Low muscle endurance in chronic polymyositis or dermatomyositis may be related to a low proportion of oxidative, slow-twitch type I fibers. Change in fiber type composition and increased muscle fiber area may contribute to improved muscle endurance and decreased muscle fatigue after a moderate physical training program.

[Current treatments of dermatomyositis and polymyositis]

Idiopathic inflammatory myositides are chronic diseases affecting predominantly the musculoskeletal system and involving high morbidity and mortality. Even when treated with glucocorticosteroids, patients often experience a progressive or relapsing course of the disease, requiring additional immunosuppressants, biologicals, or other therapeutic interventions. Randomized controlled trials on the treatment of primary myositides are still lacking, which means that the optimum therapeutic regimen has still not been defined. This article reviews the current position indicated by the data collected in standard and modern therapeutic options for the treatment of idiopathic inflammatory myositides.

Creatine supplements in patients with idiopathic inflammatory myopathies who are clinically weak after conventional pharmacologic treatment: Six-month, double-blind, randomized, placebo-controlled trial

OBJECTIVE

To test the hypothesis that oral creatine supplements with exercise are more effective than exercise alone in improving muscle function in patients with established dermatomyositis or polymyositis receiving chronic medical therapies who are clinically weak yet stable.

METHODS

In a 6-month, 2-center, double-blind, randomized controlled trial, patients were randomized to receive oral creatine supplements (8 days, 20 gm/day then 3 gm/day) or placebo. All patients followed a home exercise program. The primary outcome was aggregate functional performance time (AFPT), reflecting the ability to undertake high-intensity exercise. Secondary outcomes included a functional index measuring endurance and muscle bioenergetics on (31)P magnetic resonance spectroscopy ((31)P MRS). Patients were receiving stable immunosuppressive treatment and/or corticosteroids.

RESULTS

A total of 37 patients with polymyositis or dermatomyositis were randomized (19 to creatine, 18 to placebo); 29 completed 6 months. Intent-to-treat analyses demonstrated that AFPT improved significantly at 6 months with creatine (median decrease 13%, range -32-8%) compared with placebo (median decrease 3%, range -13-16%; P = 0.029 by Mann-Whitney U test). A completer analysis also showed significant benefits from creatine (P = 0.014). The functional index improved significantly with both creatine and placebo (P < 0.05 by paired Wilcoxon's rank sum test), with a significant benefit between groups in the completer analysis only. Phosphocreatine/beta-nucleoside triphosphate ratios using MRS increased significantly in the creatine group (P < 0.05) but not in the control group. No clinically relevant adverse events were associated with creatine.

CONCLUSION

Oral creatine supplements combined with home exercises improve functional performance without significant adverse effects in patients with polymyositis or dermatomyositis. They appear safe, effective, and inexpensive.

Muscle fatigue during dynamic contractions assessed by new spectral indices

PURPOSE

The aim of the present study was to test the applicability and sensitivity of new electromyography (EMG) spectral indices in assessing peripheral muscle fatigue during dynamic knee-extension exercise.

METHODS

Seven subjects completed 10 sets of 15 repetitions of right knee-extension exercise lifting 50% of their one-repetition maximum. Torque (T), knee-joint angle, and the interference EMG of rectus femoris muscle were recorded simultaneously. Maximal voluntary isometric contraction (MVC) was tested before and after exercise. Median spectral frequency (Fmed) and new spectral indices of muscle fatigue (FInsmk) were calculated for each repetition.

RESULTS

The rate and range of FInsmk- and Fmed-relative changes against the first repetition of the corresponding set increased gradually across successive repetitions within the set, reflecting accumulation of peripheral muscle fatigue. The maximal change of FInsmk observed in the present experiment was approximately eightfold, whereas that of Fmed was only 32%. Significant between-subject variability in the range of FInsmk changes (P < 0.0001) was found, so a hierarchical cluster analysis of muscle fatigue indices was conducted. Three distinct subgroups of subjects were identified: high (N = 1, FInsmk change > 400%), medium (N = 4, 200% < FInsmk change < 400%), and low (N = 2, FInsmk change < 200%) muscle fatigability. The changes in muscle performance during (last vs first repetition peak T, P = 0.03) and after (post- vs preexercise MVC, P = 0.012) exercise were significantly different between clusters (one-way ANOVA). The rate of fatigue development was also significantly different between clusters (linear regression analysis of Fmed and FInsmk changes).

CONCLUSIONS

The new spectral indices are a valid and reliable tool for assessment of muscle fatigability irrespective of EMG signal variability caused by dynamic muscle contractions, and these indices are more sensitive than those traditionally used.

The heart in dermatomyositis and polymyositis

Cardiovascular manifestations constitute a major cause of death in myositis. Despite this, clinically manifest cardiac involvement in polymyositis and dermatomyositis is relatively rare. In contrast, subclinical manifestations are frequently reported and are predominated by conduction abnormalities and arrhythmias detected by ECG. The most frequently reported clinically overt manifestations are congestive heart failure, conduction abnormalities, that may lead to complete heart block, and coronary artery disease. The underlying pathophysiological mechanisms that may cause cardiac manifestations involve myocarditis and coronary artery disease as well as involvement of the small vessels of the myocardium.

Diagnosis, pathogenesis and treatment of inclusion body myositis

PURPOSE OF REVIEW

We provide an update of progress gained from research into sporadic inclusion body myositis (s-IBM).

RECENT FINDINGS

Most research on s-IBM has focused on the inflammatory reaction or the accumulation of pathological proteins in vacuolated muscle fibres. The inflammatory reaction is characterized by clonal expansions of lymphocytes, predominantly CD8 cytotoxic T cells, which invade and destroy muscle fibres. That costimulatory molecules have been identified demonstrates that muscle fibres can act as antigen presenting cells, and the expression of various chemokines in muscle indicates their importance in the immunopathogenesis of s-IBM. The region of interest for a susceptibility gene in the major histocompatibility complex has been narrowed, and for the first time it has been demonstrated that a chronic viral infection can trigger the inflammatory process leading to s-IBM. The nature of the accumulated material associated with the vacuoles has been extensively investigated over the past few years. Amyloid-beta and phosphorylated tau protein in intracellular inclusions are a characteristic finding in s-IBM, which may lead to calcium dyshomeostasis and endoplasmic reticulum stress. The proteasomal system is upregulated, including immunoproteasomes. 'Molecular misreading' leading to ubiquitin mRNA mutations and accumulation of pathological ubiquitin in muscle fibres may be associated with proteasomal dysfunction. There is still no efficient treatment for s-IBM, but the effects of new, more specific immunotherapies have begun to be explored.

SUMMARY

Recent findings indicate that both inflammatory reaction and abnormal protein accumulation are important for the pathogenesis in s-IBM. The link between them continues to await elucidation.