Botulinum toxin alleviates dysphagia of patients with inclusion body myositis

An Unusual Disease With a Common Presentation: Cricopharyngeal Dysfunction in Inclusion Body Myositis

Cricopharyngeal (CP) dysfunction is a frequent cause of dysphagia among patients with inclusion body myositis. Early identification and prompt treatment is necessary because aspiration pneumonia is a leading cause of mortality among these patients. We present a case of a 57-year-old woman with a history of inclusion body myositis who presented with progressive dysphagia and aspiration pneumonia found to have CP dysfunction treated with endoscopic CP myotomy. Postoperatively, patient's dysphagia improved with no further episodes of aspiration at 2-year follow-up.

Diagnosing and managing dysphagia in inclusion body myositis: a systematic review

OBJECTIVES

Dysphagia is a common debilitating clinical feature of IBM. However, the impact of dysphagia in IBM has been historically overlooked. This study aimed to identify, evaluate and summarize the evidence regarding the assessment and management of dysphagia in persons with IBM undergoing treatment.

METHODS

A systematic review was conducted using a multiengine search following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. Eligible studies had to employ an intervention for persons with IBM, report a swallowing outcome and be published in English. Quality assessments of the eligible studies were performed.

RESULTS

Of 239 studies found, 19 met the inclusion criteria. One study was rated as 'fair' and the rest as 'poor' quality, particularly due to the lack of published and validated swallowing assessment procedures and outcome measures. Cricopharyngeal (CP) dysfunction (12/19) was the most commonly reported swallowing abnormality. Interventions for disease management included pharmacological agents (10/19), followed by surgical (3/19), behavioral (1/19) and combined approaches (5/19). Interventions with immunosuppressants, botulinum toxin injection, balloon dilation and/or CP myotomy led to mixed and transient benefits. Few studies examining statins or behavioral therapies (primarily focused on respiratory function) showed no effects for dysphagia.

CONCLUSION

Various interventions have been reported to temporarily improve dysphagia in persons with IBM. However, these findings are based on limited and overall low-quality evidence. This study cautions against the generalization of these findings and emphasizes the need for further systematic research to improve the diagnosis and management of dysphagia in IBM.

Inclusion body myositis and dysphagia. Presentation, intervention and outcome at a swallowing clinic

OBJECTIVE

This study reviewed patients with inclusion body myositis who were referred for assessment of dysphagia at a tertiary swallow clinic. It describes symptoms at presentation, imaging and management strategies.

METHOD

A retrospective review of electronic patient records was performed between 2016 and 2020.

RESULTS

Twenty-four patients were included, with a mean age of 72 years. Baseline modified Sydney Swallow Questionnaires identified problems with hard or dry food, food sticking, and repeated swallowing. Twenty-two patients had a Reflux Symptom Index score that could indicate significant reflux. Video swallow identified specific problems, including tongue base retraction (96 per cent) and residual pharyngeal pooling (92 per cent). Seven patients (30 per cent) had features of aspiration on imaging despite a median penetration-aspiration scale score of 2. Four patients received balloon dilatation, and two patients underwent cricopharyngeal myotomy.

CONCLUSION

This study helped to profile features of dysphagia in patients with inclusion body myositis. More evidence is needed to determine the most effective management pathway for these patients.

Autoimmune inflammatory myopathies

The autoimmune inflammatory myopathies constitute a heterogeneous group of acquired myopathies that have in common the presence of endomysial inflammation and moderate to severe muscle weakness. Based on currently evolved distinct clinical, histologic, immunopathologic, and autoantibody features, these disorders can be best classified as dermatomyositis, necrotizing autoimmune myositis, antisynthetase syndrome-overlap myositis, and inclusion body myositis. Although polymyositis is no longer considered a distinct subset but rather an extinct entity, it is herein described because its clinicopathologic information has provided over many years fundamental information on T-cell-mediated myocytotoxicity, especially in reference to inclusion body myositis. Each inflammatory myopathy subset has distinct immunopathogenesis, prognosis, and response to immunotherapies, necessitating the need to correctly diagnose each subtype from the outset and avoid disease mimics. The paper describes the main clinical characteristics that aid in the diagnosis of each myositis subtype, highlights the distinct features on muscle morphology and immunopathology, elaborates on the potential role of autoantibodies in pathogenesis or diagnosis , and clarifies common uncertainties in reference to putative triggering factors such as statins and viruses including the 2019-coronavirus-2 pandemic. It extensively describes the main autoimmune markers related to autoinvasive myocytotoxic T-cells, activated B-cells, complement, cytokines, and the possible role of innate immunity. The concomitant myodegenerative features seen in inclusion body myositis along with their interrelationship between inflammation and degeneration are specifically emphasized. Finally, practical guidelines on the best therapeutic approaches are summarized based on up-to-date knowledge and controlled studies, highlighting the prospects of future immunotherapies and ongoing controversies.

Prevention of Adverse Outcomes and Treatment Side Effects in Patients with Neuromuscular Disorders

In this article, we review prevention of serious adverse clinical outcomes and treatment side effects in patients with neuromuscular disorders including myopathies and myasthenia gravis. While neither of these entities is preventable, their course can often be modified, and severe sequelae may be prevented, with the identification of risk factors and proactive attention toward treatment planning.

Possible future avenues for myositis therapeutics: DM, IMNM and IBM

Idiopathic inflammatory myopathies (IIMs) represent a heterogeneous group of systemic autoimmune diseases characterized by immune-mediated muscle injury. As insights into pathogenesis of IIM evolve, novel therapeutic strategies have become available to optimize outcomes. Herein, we summarize novel and emerging strategies in the management of dermatomyositis (DM), immunemediated necrotizing myopathy (IMNM), and inclusion body myositis (IBM).

Botulinum toxin treatment improves dysphagia in patients with oculopharyngeal muscular dystrophy and sporadic inclusion body myositis

OBJECTIVE

Dysphagia can be troublesome in sporadic inclusion body myositis (sIBM) and oculopharyngeal muscular dystrophy (OPMD), but no established treatment exists. Cricopharyngeal muscle botulinum toxin injection has at case level been reported to be effective. We evaluated safety and efficacy of botulinum toxin injections in the cricopharyngeal muscle in patients with dysphagia due to sIBM or OPMD.

METHODS

Participants were included from our outpatient clinic. Cricopharyngeal constriction was confirmed by laryngoscopy. After EMG confirmation of needle placement in the cricopharyngeal muscle, botulinum toxin A was injected in awake patients. An individualized dose of 5-10 units of botulinum toxin A was applied initially and titrated up a maximum of 3 times. Outcome measures were change in dysphagia questionnaire, timed cold-water swallow test and subjective dysphagia status (worse, unchanged, improved). Due to the need for individualized dosing and a limited number of available patients, an uncontrolled, un-blinded design was used.

RESULTS

Thirteen patients, 3 with OPMD, received at least 1 injection. In the dysphagia questionnaire, all but 2 subjects, none with subjective worsening, improved (p < 0.001). Subjectively, seven felt an improvement, 4 no change and 2 a worsening. No overall change was seen the timed cold-water swallow test. No serious adverse events were observed.

CONCLUSION

Botulinum toxin injection of the cricopharyngeal muscle in patients with OPMD and sIBM had a beneficial effect on dysphagia in most of the treated patients. Two of 13 patients experienced a temporary worsening not reflected in dysphagia score. Limitations are the un-blinded and un-randomized design and subjective assessments methods.

PROSPECTIVE TRIAL REGISTRATION

EudraCT-number: 2014-002210-23.

Detecting myositis as a cause of unexplained dysphagia: Proposal for a diagnostic algorithm

BACKGROUND AND PURPOSE

Idiopathic inflammatory myopathy (IIM) can present with dysphagia as a leading or only symptom. In such cases, diagnostic evaluation may be difficult, especially if serological and electromyographical findings are unsuspicious. In this observational study we propose and evaluate a diagnostic algorithm to identify IIM as a cause of unexplained dysphagia.

METHODS

Over a period of 4 years, patients with unexplained dysphagia were offered diagnostic evaluation according to a specific algorithm: The pattern of dysphagia was characterized by instrumental assessment (swallowing endoscopy, videofluoroscopy, high-resolution manometry). Patients with an IIM-compatible dysphagia pattern were subjected to further IIM-focused diagnostic procedures, including whole-body muscle magnetic resonance imaging, electromyography, creatine kinase blood level, IIM antibody panel and, as a final diagnostic step, muscle biopsy. Muscle biopsies were taken from affected muscles. In cases where no other muscles showed abnormalities, the cricopharyngeal muscle was targeted.

RESULTS

Seventy-two patients presented with IIM-compatible dysphagia as a leading or only symptom. As a result of the specific diagnostic approach, 19 of these patients were diagnosed with IIM according to the European League Against Rheumatism (EULAR) criteria. Eighteen patients received immunomodulatory therapy as a result of the diagnosis. Of 10 patients with follow-up swallowing examination, dysphagia improved in three patients after therapy, while it remained at least stable in six patients.

CONCLUSIONS

Idiopathic inflammatory myopathy constitutes a potentially treatable etiology in patients with unexplained dysphagia. The diagnostic algorithm presented in this study helps to identify patients with an IIM-compatible dysphagia pattern and to assign those patients for further IIM-focused diagnostic and therapeutic procedures.

Scleroderma and the Esophagus

The gastrointestinal tract is the second largest organ system in the body and is often affected by connective tissue disorders. Scleroderma is the classic rheumatologic disease affecting the esophagus; more than 90% of patients with scleroderma have esophageal involvement. This article highlights esophageal manifestations of scleroderma, focusing on pathogenesis, clinical presentation, diagnostic considerations, and treatment options. In addition, this article briefly reviews the esophageal manifestations of other key connective tissue disorders, including mixed connective tissue disease, myositis, Sjogren syndrome, systemic lupus erythematosus, fibromyalgia, and Ehlers-Danlos syndrome.

A severe case of non-infective myositis six weeks post intramuscular injections of Onabotulinum toxin A (Botox) in a young man with tetraplegia: case report

INTRODUCTION

Myositis of unknown aetiology might be a very rare complication of intramuscular injections of onabotulinum toxin A (Botox) for spasticity treatment.

CASE PRESENTATION

We describe a case of significant myositis of unknown aetiology in a 17-year-old man, who was admitted for rehabilitation 4 months after his initial spinal cord injury (SCI) as a result of a mountain bike accident. He has an incomplete tetraplegia, C4 AIS B international Standards for Neurological Classification for Spinal Cord Injury (ISNCSCI) [1] due to C5 vertebra 3 column fracture [2]. He had severe spasticity of his lower limb muscles treated with Botox, following which, he required two acute hospital transfers for diagnosis and management of myositis.

DISCUSSION

This is a severe unusual presentation of myositis caused by intramuscular botulinum toxin for treatment of spasticity, in the frequent setting of spasticity where intramuscular botulinum toxin injections are routinely used.

Myogenic Cell Transplantation in Genetic and Acquired Diseases of Skeletal Muscle

This article will review myogenic cell transplantation for congenital and acquired diseases of skeletal muscle. There are already a number of excellent reviews on this topic, but they are mostly focused on a specific disease, muscular dystrophies and in particular Duchenne Muscular Dystrophy. There are also recent reviews on cell transplantation for inflammatory myopathies, volumetric muscle loss (VML) (this usually with biomaterials), sarcopenia and sphincter incontinence, mainly urinary but also fecal. We believe it would be useful at this stage, to compare the same strategy as adopted in all these different diseases, in order to outline similarities and differences in cell source, pre-clinical models, administration route, and outcome measures. This in turn may help to understand which common or disease-specific problems have so far limited clinical success of cell transplantation in this area, especially when compared to other fields, such as epithelial cell transplantation. We also hope that this may be useful to people outside the field to get a comprehensive view in a single review. As for any cell transplantation procedure, the choice between autologous and heterologous cells is dictated by a number of criteria, such as cell availability, possibility of in vitro expansion to reach the number required, need for genetic correction for many but not necessarily all muscular dystrophies, and immune reaction, mainly to a heterologous, even if HLA-matched cells and, to a minor extent, to the therapeutic gene product, a possible antigen for the patient. Finally, induced pluripotent stem cell derivatives, that have entered clinical experimentation for other diseases, may in the future offer a bank of immune-privileged cells, available for all patients and after a genetic correction for muscular dystrophies and other myopathies.

Predictors, outcome and characteristics of oropharyngeal dysphagia in idiopathic inflammatory myopathy

INTRODUCTION

Oropharyngeal dysphagia is a clinical hallmark of idiopathic inflammatory myopathy (IIM). This study investigated predictors, outcome, and characteristics of oropharyngeal dysphagia in patients with different types of IIM.

METHODS

Flexible endoscopic evaluation of swallowing (FEES) videos of 71 IIM patients were retrospectively analyzed for bolus spillage, penetration, aspiration, and pharyngeal residue. Based on these findings, dysphagia severity was rated. Regression analyses were performed to investigate demographic and disease-specific predictors of dysphagia severity and pneumonia as outcome-relevant complications of dysphagia. A score was developed to rate the quality of the endoscopic white-out as a surrogate marker for pharyngeal muscle weakness with consecutive residue.

RESULTS

Our analysis revealed no independent predictors of dysphagia severity. Dysphagia severity, however, was an independent predictor for pneumonia, which occurred in 24% of patients. Pharyngeal residue with risk of postdeglutitive aspiration was the most common dysphagia pattern. Attenuation of the endoscopic white-out was related to residue severity.

DISCUSSION

Dysphagia in IIM assessed with FEES is associated with relevant complications, such as aspiration pneumonia, and must be considered independently of peripheral muscle weakness and disease duration. Swallowing impairment mainly presents with pharyngeal residue. The quality of the white-out may serve as a semi-quantitative surrogate marker for pharyngeal contractility.

Inflammatory Myopathies: Utility of Antibody Testing

Inflammatory myopathies are a group of immune-mediated muscle disorders comprising dermatomyositis; polymyositis; overlap myositis, including antisynthetase syndromes and nonspecific myositis, immune-mediated necrotizing myopathies, and sporadic inclusion body myositis. They are now much more eloquently classified both pathologically and clinically because of the discovery of several myositis-specific and myositis-associated antibodies. These antibodies also aid in choosing the best treatment options in each case. Based on the initial classifications of inflammatory myopathies, inclusion body myositis, overlap myositis, and necrotizing myositis were all included in the polymyositis group. This article discusses cases, diagnostic tools, associated antibodies, and pathology.

Impact and Management of Dysphagia in Inflammatory Myopathies

PURPOSE OF REVIEW

Dysphagia is a common symptom in inflammatory myopathies. This review provides an overview on the epidemiology, clinical impact, and management of dysphagia in myositis. Relevant diagnostic tools and treatment strategies are discussed.

RECENT FINDINGS

Dysphagia can occur in any inflammatory myopathy, particularly in inclusion body myositis (IBM). It can lead to malnutrition or aspiration with subsequent pneumonia or even death. Dysphagia can be explored and monitored by patient-reported outcome scales for swallowing. New diagnostic tools such as real-time MRI and oro-pharyngo-esophageal scintigraphy have been studied for assessing dysphagia. Botulinum toxin injection can alleviate dysphagia in IBM. High-dose glucocorticosteroids are considered a first-line treatment for dysphagia in all other myositis subforms. Evaluation of dysphagia in myositis requires thorough clinical workup and appropriate instrumental procedures. Treatment options are available for dysphagia, but controlled trials and consensus on best patient care are required for this important symptom.

The Impact of Dysphagia in Myositis: A Systematic Review and Meta-Analysis

(1) Background: Dysphagia is a clinical hallmark and part of the current American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) diagnostic criteria for idiopathic inflammatory myopathy (IIM). However, the data on dysphagia in IIM are heterogenous and partly conflicting. The aim of this study was to conduct a systematic review on epidemiology, pathophysiology, outcome and therapy and a meta-analysis on the prevalence of dysphagia in IIM. (2) Methods: Medline was systematically searched for all relevant articles. A random effect model was chosen to estimate the pooled prevalence of dysphagia in the overall cohort of patients with IIM and in different subgroups. (3) Results: 234 studies were included in the review and 116 (10,382 subjects) in the meta-analysis. Dysphagia can occur as initial or sole symptom. The overall pooled prevalence estimate in IIM was 36% and with 56% particularly high in inclusion body myositis. The prevalence estimate was significantly higher in patients with cancer-associated myositis and with NXP2 autoantibodies. Dysphagia is caused by inflammatory involvement of the swallowing muscles, which can lead to reduced pharyngeal contractility, cricopharyngeal dysfunction, reduced laryngeal elevation and hypomotility of the esophagus. Swallowing disorders not only impair the quality of life but can lead to serious complications such as aspiration pneumonia, thus increasing mortality. Beneficial treatment approaches reported include immunomodulatory therapy, the treatment of associated malignant diseases or interventional procedures targeting the cricopharyngeal muscle such as myotomy, dilatation or botulinum toxin injections. (4) Conclusion: Dysphagia should be included as a therapeutic target, especially in the outlined high-risk groups.

Dysphagia in Myositis: A Study of the Structural and Physiologic Changes Resulting in Disordered Swallowing

OBJECTIVES

Dysphagia in patients with myositis is associated with an increased risk of aspiration pneumonia. However, the pathophysiology of dysphagia is poorly understood. The aim of this study was to understand how myositis affects swallowing physiology on videofluoroscopic swallow study.

DESIGN

This is a retrospective review of video fluoroscopic swallowing studies on 23 myositis patients with dysphagia from 2011 to 2016. Swallow studies were analyzed by timing of swallowing events and duration of swallowing events, diameter of upper esophageal sphincter opening, Modified Barium Swallow Impairment Profile, and Penetration-Aspiration Scale. The outcome measures for patients were compared with an archived videofluoroscopic swallow study from healthy, age-matched participants by Wilcoxon rank-sum tests.

RESULTS

Patients with myositis had a shorter duration of upper esophageal sphincter opening (P < 0.0001) and laryngeal vestibule closure (P < 0.0001) than healthy subjects. The diameter of upper esophageal sphincter opening did not differ between groups. Patients with myositis presented with higher scores on the MBSIMP than healthy subjects, indicating great impairment particularly during the pharyngeal phase of swallowing, and a higher frequency of penetration and aspiration.

CONCLUSIONS

Dysphagia in patients with myositis may be attributed to reduced endurance of swallowing musculature rather than mechanical obstruction of the upper esophageal sphincter.

Exploring the efficacy of the expiratory muscle strength trainer to improve swallowing in inclusion body myositis: A pilot study

Inclusion Body Myositis (IBM) is the most common acquired myopathy in older individuals with more than two thirds of patients experiencing impaired swallowing. There are currently no standardized exercise therapies to improve or sustain swallowing despite good evidence for exercise therapy in limb muscles. Reduced upper esophageal sphincter opening is a common abnormality associated with dysphagia in IBM. This pilot study recruited IBM patients with abnormal upper esophageal sphincter function and dysphagia into an exercise program. It was hypothesized that regular practice using the Expiratory Muscle Strength Trainer (EMST) device would improve hyolaryngeal movement by strengthening suprahyoid musculature and facilitate opening of the upper esophageal sphincter thereby improving swallowing and quality of life. Overall, IBM patients who used the EMST device demonstrated no improvement in swallowing function. Consistent with that result, there was also no change in measures of quality of life. However, further studies are needed to elucidate whether it has a preventative role in the development or progression of dysphagia in IBM as there is a suggestion that patients with a shorter duration of disease may have had some benefit. This research provides pilot data and recommendations that will guide future studies on exercise therapy and swallowing in this area.

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.

Dysphagia in Patients with Sporadic Inclusion Body Myositis: Management Challenges

Dysphagia in inclusion body myositis (IBM) is common and associated with increased mortality and morbidity due to aspiration pneumonia, malnutrition and dehydration. There is currently no consensus on treatment of dysphagia in IBM and outcomes are variable depending on timing of intervention, patient preference and available expertise. There is a paucity of research exploring the pathophysiology of dysphagia in IBM and appropriate investigations. Increased knowledge of the aetiopathogenesis is likely to change the approach to treatment as well as improve the quality of life for patients. This review explores the epidemiology and pathophysiology of dysphagia in IBM and the currently available treatment strategies.

A Patient with Sjogren's Syndrome and Subsequent Diagnosis of Inclusion Body Myositis and Light-Chain Amyloidosis

We discuss a challenging case of a 58-year-old Vietnamese-American woman who presented to her new primary care provider with an 8-year history of slowly progressive dysphagia, hoarseness, muscle weakness with associated frequent falls, and weight loss. She eventually reported dry eyes and dry mouth, and she was diagnosed with Sjogren's syndrome. Subsequently, she was additionally diagnosed with inclusion body myositis and gastric light-chain (AL) amyloidosis. Although inclusion body myositis has been previously associated with Sjogren's syndrome, inclusion body myositis is rare in non-Caucasians, and the trio of Sjogren's syndrome, inclusion body myositis, and AL amyloidosis has not been previously reported. Sjogren's syndrome is a systemic autoimmune condition characterized by ocular and oral dryness. It is one of the most common rheumatologic disorders in the USA and worldwide. Early diagnosis of Sjogren's is particularly important given the frequency and variety of associated autoimmune diseases and extraglandular manifestations. Furthermore, although inclusion body myositis has a low prevalence, it is the most common inflammatory myopathy in older adults and is unfortunately associated with long delays in diagnosis, so knowledge of this disorder is also crucial for practicing internists.

Classification and management of adult inflammatory myopathies

Inflammatory myopathies, collectively known as myositis, are heterogeneous disorders characterised by muscle inflammation, and frequently accompanied by extramuscular manifestations that affect the skin, lung, and joints. Patients with inflammatory myopathies were previously classified as having dermatomyositis if characteristic rashes accompanied the muscle involvement, and as having polymyositis if no rashes were present. Five main types of inflammatory myopathies are now widely recognised: dermatomyositis, immune-mediated necrotising myopathy, sporadic inclusion-body myositis, overlap myositis (including antisynthetase syndrome), and polymyositis. The discovery of autoantibodies that are specifically associated with characteristic clinical phenotypes has been instrumental to the understanding of inflammatory myopathies. Treatment is still largely based on expert opinion, but several studies have shown effectiveness of different therapies in various subsets of inflammatory myopathies. These advances will undoubtedly improve the outcomes of patients with inflammatory myopathies.

Guidelines of the Brazilian Society of Rheumatology for the treatment of systemic autoimmune myopathies

BACKGROUND

Recommendations of the Myopathy Committee of the Brazilian Society of Rheumatology for the management and therapy of systemic autoimmune myopathies (SAM).

MAIN BODY

The review of the literature was done in the search for the Medline (PubMed), Embase and Cochrane databases including studies published until June 2018. The Prisma was used for the systematic review and the articles were evaluated according to the levels of Oxford evidence. Ten recommendations were developed addressing the management and therapy of systemic autoimmune myopathies.

CONCLUSIONS

Robust data to guide the therapeutic process are scarce. Although not proven effective in controlled clinical trials, glucocorticoid represents first-line drugs in the treatment of SAM. Intravenous immunoglobulin is considered in induction for refractory cases of SAM or when immunosuppressive drugs are contra-indicated. Consideration should be given to the early introduction of immunosuppressive drugs. There is no specific period determined for the suspension of glucocorticoid and immunosuppressive drugs when individually evaluating patients with SAM. A key component for treatment in an early rehabilitation program is the inclusion of strength-building and aerobic exercises, in addition to a rigorous evaluation of these activities for remission of disease and the education of the patient and his/her caregivers.

Inclusion Body Myositis: Update on Pathogenesis and Treatment

Inclusion body myositis is the most common acquired myopathy after the age of 50. It is characterized by progressive asymmetric weakness predominantly affecting the quadriceps and/or finger flexors. Loss of ambulation and dysphagia are major complications of the disease. Inclusion body myositis can be associated with cytosolic 5'-nucleotidase 1A antibodies. Muscle biopsy usually shows inflammatory cells surrounding and invading non-necrotic muscle fibers, rimmed vacuoles, congophilic inclusions, and protein aggregates. Disease pathogenesis remains poorly understood and consists of an interplay between inflammatory and degenerative pathways. Antigen-driven, clonally restricted, cytotoxic T cells represent a main feature of the inflammatory component, whereas abnormal protein homeostasis with protein misfolding, aggregation, and dysfunctional protein disposal is the hallmark of the degenerative component. Inclusion body myositis remains refractory to treatment. Better understanding of the disease pathogenesis led to the identification of novel therapeutic targets, addressing both the inflammatory and degenerative pathways.

Advances in the early diagnosis and therapy of inclusion body myositis

PURPOSE OF REVIEW

To describe recent advancements in diagnostic and therapeutic approaches to inclusion body myositis (IBM).

RECENT FINDINGS

Our understanding of the implications of anti-cytosolic 5'-nucleotidase 1A autoantibody status in IBM and other diseases is increasing. Muscle imaging using magnetic resonance techniques and ultrasound is increasingly being performed and characteristic patterns of muscle involvement may help with diagnosis. Longitudinal imaging studies are likely to help with monitoring and as an outcome measure in clinical trials. Recent small-scale studies of Arimoclomol and Rapamycin have shown promising results and further investigation of these medications is ongoing. Exercise is likely to form an increasingly important facet of management of patients with IBM, but the optimal type of exercise programme to enrol patients in is not yet determined.

SUMMARY

Antibody testing and muscle imaging results may improve our ability to diagnose IBM and the availability of effective disease modifying treatments targeting novel non-inflammatory pathways could soon become a reality. It remains the duty of those involved in the management of patients with IBM to facilitate involvement in clinical trials and other research studies.

Current Classification and Management of Inflammatory Myopathies

Inflammatory disorders of the skeletal muscle include polymyositis (PM), dermatomyositis (DM), (immune mediated) necrotizing myopathy (NM), overlap syndrome with myositis (overlap myositis, OM) including anti-synthetase syndrome (ASS), and inclusion body myositis (IBM). Whereas DM occurs in children and adults, all other forms of myositis mostly develop in middle aged individuals. Apart from a slowly progressive, chronic disease course in IBM, patients with myositis typically present with a subacute onset of weakness of arms and legs, often associated with pain and clearly elevated creatine kinase in the serum. PM, DM and most patients with NM and OM usually respond to immunosuppressive therapy, whereas IBM is largely refractory to treatment. The diagnosis of myositis requires careful and combinatorial assessment of (1) clinical symptoms including pattern of weakness and paraclinical tests such as MRI of the muscle and electromyography (EMG), (2) broad analysis of auto-antibodies associated with myositis, and (3) detailed histopathological work-up of a skeletal muscle biopsy. This review provides a comprehensive overview of the current classification, diagnostic pathway, treatment regimen and pathomechanistic understanding of myositis.