A comparison of daily and alternate-day prednisone therapy in the treatment of Duchenne muscular dystrophy

Patient- and caregiver-reported impact of symptoms in Duchenne muscular dystrophy

INTRODUCTION/AIMS

To better understand the disease burden faced by individuals with Duchenne muscular dystrophy (DMD) of all ages and elucidate potential targets for therapeutics, this study determined the prevalence and relative importance of symptoms experienced by individuals with DMD and identified factors associated with a higher disease burden.

METHODS

We conducted qualitative interviews with individuals with DMD and caregivers of individuals with DMD to identify potential symptoms of importance to those living with DMD. We subsequently performed a cross-sectional study to assess which symptoms have the highest prevalence and importance in DMD and to determine which factors are associated with a higher disease burden.

RESULTS

Thirty-nine individuals, aged 11 years and above, provided 3262 quotes regarding the symptomatic burden of DMD. Two hundred participants (87 individuals with DMD and 113 caregivers) participated in a subsequent cross-sectional study. Individuals with DMD identified limitations with mobility or walking (100%), inability to do activities (98.9%), trouble getting around (97.6%), and leg weakness (97.6%) as the most prevalent and life altering symptomatic themes in DMD. The symptomatic themes with the highest prevalence, as reported by caregivers on behalf of those with DMD for whom they care, were limitations with mobility or walking (90.3%), leg weakness (89.2%), and emotional issues (79.6%). Steroid/glucocorticoid use (e.g., prednisone or deflazacort) was associated with a lower level of disease burden in DMD.

DISCUSSION

There are many symptomatic themes that contribute to disease burden in individuals with DMD. These symptoms are identified by both individuals with DMD and their caregivers and have a variable level of importance and prevalence in the DMD population.

On the path to evidence-based therapy in neuromuscular disorders

Neuromuscular disorders encompass a diverse group of acquired and genetic diseases characterized by loss of motor functionality. Although cure is the goal, many therapeutic strategies have been envisioned and are being studied in randomized clinical trials and entered clinical practice. As in all scientific endeavors, the successful clinical translation depends on the quality and translatability of preclinical findings and on the predictive value and feasibility of the clinical models. This chapter focuses on five exemplary diseases: childhood spinal muscular atrophy (SMA), Charcot-Marie-Tooth (CMT) disorders, chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), acquired autoimmune myasthenia gravis (MG), and Duchenne muscular dystrophy (DMD), to illustrate the progress made on the path to evidenced-based therapy.

Childhood muscular dystrophies

Infancy- and childhood-onset muscular dystrophies are associated with a characteristic distribution and progression of motor dysfunction. The underlying causes of progressive childhood muscular dystrophies are heterogeneous involving diverse genetic pathways and genes that encode proteins of the plasma membrane, extracellular matrix, sarcomere, and nuclear membrane components. The prototypical clinicopathological features in an affected child may be adequate to fully distinguish it from other likely diagnoses based on four common features: (1) weakness and wasting of pelvic-femoral and scapular muscles with involvement of heart muscle; (2) elevation of serum muscle enzymes in particular serum creatine kinase; (3) necrosis and regeneration of myofibers; and (4) molecular neurogenetic assessment particularly utilizing next-generation sequencing of the genome of the likeliest candidates genes in an index case or family proband. A number of different animal models of therapeutic strategies have been developed for gene transfer therapy, but so far these techniques have not yet entered clinical practice. Treatment remains for the most part symptomatic with the goal of ameliorating locomotor and cardiorespiratory manifestations of the disease.

Prognostic indicators of disease progression in Duchenne muscular dystrophy: A literature review and evidence synthesis

BACKGROUND

Duchenne muscular dystrophy (DMD) is a rare, severely debilitating, and fatal neuromuscular disease characterized by progressive muscle degeneration. Like in many orphan diseases, randomized controlled trials are uncommon in DMD, resulting in the need to indirectly compare treatment effects, for example by pooling individual patient-level data from multiple sources. However, to derive reliable estimates, it is necessary to ensure that the samples considered are comparable with respect to factors significantly affecting the clinical progression of the disease. To help inform such analyses, the objective of this study was to review and synthesise published evidence of prognostic indicators of disease progression in DMD. We searched MEDLINE (via Ovid), Embase (via Ovid) and the Cochrane Library (via Wiley) for records published from inception up until April 23 2021, reporting evidence of prognostic indicators of disease progression in DMD. Risk of bias was established with the grading system of the Centre for Evidence-Based Medicine (CEBM).

RESULTS

Our search included 135 studies involving 25,610 patients from 18 countries across six continents (Africa, Asia, Australia, Europe, North America and South America). We identified a total of 23 prognostic indicators of disease progression in DMD, namely age at diagnosis, age at onset of symptoms, ataluren treatment, ATL1102, BMI, cardiac medication, DMD genetic modifiers, DMD mutation type, drisapersen, edasalonexent, eteplirsen, glucocorticoid exposure, height, idebenone, lower limb surgery, orthoses, oxandrolone, spinal surgery, TAS-205, vamorolone, vitlolarsen, ventilation support, and weight. Of these, cardiac medication, DMD genetic modifiers, DMD mutation type, and glucocorticoid exposure were designated core prognostic indicators, each supported by a high level of evidence and significantly affecting a wide range of clinical outcomes.

CONCLUSION

This study provides a current summary of prognostic indicators of disease progression in DMD, which will help inform the design of comparative analyses and future data collection initiatives in this patient population.

Glucocorticoids for therapeutic immunosuppression: Clinical pearls for the practicing neurologist

Given widespread use of glucocorticoid therapy in neurologic disease, understanding glucocorticoid pharmacology and risk is paramount for the practicing neurologist. While dosing and tapering regimens vary depending on the neurological disease and indication being treated, there are important general principles of glucocorticoid prescribing and monitoring that can guide clinical decision-making. Glucocorticoid-related toxicities can occur across multiple organ systems, including hypertension; dyslipidemia; weight gain; hyperglycemia; osteoporosis and avascular necrosis; myopathy; gastrointestinal bleeding; infection; and neuropsychiatric effects with sleep, mood disturbance and cognition. This narrative review provides a practical framework for safe and responsible prescribing of this therapeutic class of medications, including appreciation of immunosuppressive consequences, risk mitigation strategies, dosing and tapering, and recognition of adrenal insufficiency and glucocorticoid withdrawal.

Knee Strength and Ankle Range of Motion Impacts on Timed Function Tests in Duchenne Muscular Dystrophy: In the Era of Glucocorticoids

BACKGROUND

Duchenne Muscular Dystrophy (DMD) is a neuromuscular disorder that presents in childhood and is characterized by slowly progressive proximal weakness and lower extremity contractures that limit ambulatory ability [1, 2]. Contractures develop in the ankles, knees, and hips due to muscle imbalances, fibrotic changes, loss of strength, and static positioning [2, 5]. Currently, standards of care guidelines emphasize the importance of maintaining good musculoskeletal alignment through stretching, bracing, and glucocorticoid (GC) therapy to preserve strength and function.

METHODS

This is a retrospective analysis of prospectively collected data through the CINRG Duchenne Natural history study (DNHS). The objectives of this analysis are to understand the progression of ankle contractures for individuals with DMD and to investigate the relationship between progressive lower limb contractures, knee strength, and Timed Function Tests.A collection of TFTs including supine to stand (STS), 10 meter walk test (10MWT), and timed stair climbing (4SC) have been used to monitor disease progression and are predictive of loss of ambulation in these patients [4]. Multiple factors contribute to loss of ambulation, including progressive loss of strength and contracture development that leads to changing biomechanical demands for ambulation. A better understanding of the changes in strength and range of motion (ROM) that contribute to loss of function is important in a more individualized rehabilitation management plan. In this longitudinal study, we measured strength using quantitative muscle testing (QMT) with the CINRG Quantitative Measurement System (CQMS)), ROM was measuresed with a goniometer and TFTs were measured using a standard stopwatch and methodology.

RESULTS

We enrolled 440 participants; mean baseline age was 8.9 (2.1, 28.0) years with 1321 observations used for analysis. GC use was stratified based on duration on drug with 18.7%at <  6 months or naïve; 4.3%<1 year; 58.0%1 <  10 years; and 19.3%between 10-25 years of GC use. Ankle ROM was better for those on GC compared to GC naive but did not significantly influence long-term progression rates. QMT, ROM, age and GCs contribute to speed of TFTs. Knee extension (KE) strength and Dorsiflexion (DF) ROM are significant predictors of speed for all TFTs (p <  0.001). Of the variables used in this analysis, KE strength is the primary predictor of walking speed, estimating that every pound increase in KE results in a 0.042 m/s improvement in 10MWT, and a smaller similar increase of 0.009 m/s with every degree of ankle DF ROM.

CONCLUSION

GC use provides an improvement in strength and ROM but does not affect rate of change. Knee strength has a greater influence on speed of TFTs than DF ROM, although both are statistically significant predictors of speed. Results show that retaining knee strength [1, 2], along with joint flexibility, may be important factors in the ability to perform walking, climbing and supine to stand activities.

Intermittent versus daily regimen of prednisolone in ambulatory boys with Duchenne muscular dystrophy: A randomized, open-label trial

INTRODUCTION/AIMS

Corticosteroids prolong ambulation and improve muscle power among boys with Duchenne muscular dystrophy (DMD). However, the optimal steroid regimen remains unclear. Hence, this study was undertaken to compare the efficacy of daily- versus intermittent-steroid regimens in ambulatory boys with DMD.

METHODS

In this single-center, open-label randomized trial, 72 children were randomized to receive either daily prednisolone (0.75 mg/kg/day) or intermittent prednisolone (0.75 mg/kg/day, for first 10 days of every month). The primary outcome measure was the difference in average score on manual muscle testing (MMT) at baseline and after 6 mo of steroids. A difference of >0.2 was hypothesized to be significant. Secondary outcomes included changes in timed functions, muscular dystrophy-specific functional-rating scale score, peak torque, average power, and pulmonary function.

RESULTS

In the intention-to-treat analysis, the mean (SD) change in MMT scores was 0.17 (0.15) and 0.08 (0.10) for the daily and intermittent steroid groups, respectively. The mean difference between the two interventions was 0.10 (95% confidence interval [CI] = 0.04-0.16; P = .003), which although significant was less than the predefined value of 0.2. Statistically significantly improvements were observed with daily-steroid regimen in the Gowers time (P = .01), nine-metre walk test (P = .02) and average power (P = .02) as compared to intermittent-steroid regimen. A total of 19/32 (52.8%) children in the daily-steroid group and 8/29 (27%) children in the intermittent-steroid group experienced some form of adverse effect (P = .02).

DISCUSSION

Over a short-term period, the intermittent-steroid regimen was non-inferior to the daily-steroid regime in preserving muscle strength among children with DMD. However, better improvement of functional measures was observed with daily-steroid administration. The frequency of individual side effects was similar between the two groups.

Steroid Responsiveness in Duchenne Muscular Dystrophy - Predictive Value of Epigenetic Regulator Histone Deacetylase 2

OBJECTIVE

To find the role of an epigenetic regulator histone deacetylase (HDAC-2) in predicting steroid responsiveness in patients with Duchenne muscular dystrophy (DMD).

METHODS

Peripheral blood mononuclear cells were isolated from three milliliters of venous blood sample of patients with DMD for estimation of HDAC-2 levels. The patients were then given prednisolone at 0.75 mg/kg/d and followed up for response. Improvement in muscle power and timed function tests were evaluated 2 monthly for 6 mo. Side- effects of steroids were also noted.

RESULTS

HDAC-2 values showed a linear correlation with improvement in muscle power at 6 mo as reflected in direct assessment and in various functional tests. When ≥3 point change from baseline was considered in power of various muscle groups at 6 mo as cut off to distinguish good responders (GR) from poor responders (PR) of steroid, a HDAC-2 value of ≥4.40 seemed to be 92.6% sensitive and 100% specific to distinguish GRs.

CONCLUSIONS

The degree of improvement in power and various timed function tests at 6 mo could be predicted from the HDAC-2 value of the individual patient recorded at baseline. HDAC-2 levels at baseline might be a good biomarker for predicting steroid response in patients with DMD.

Glucocorticoid-Associated Demise of a Patient With Duchenne Muscular Dystrophy

We describe the clinical deterioration of a 26-yr-old man with Duchenne muscular dystrophy on oral daily high-dose deflazacort. Although this daily regimen was targeted to benefit ambulation and respiration, it resulted in premature death with lethal sequelae from liver failure, decubiti, diabetes mellitus, and morbid obesity. This case illustrates the need for further research weighing risk versus benefit of daily glucocorticoid therapy, specifically deflazacort, in Duchenne muscular dystrophy patients. Thus, curtailment of daily dosing to eliminate dire sequelae in patients living longer into adulthood than ever before is recommended.

Clinical practice with steroid therapy for Duchenne muscular dystrophy: An expert survey in Asia and Oceania

BACKGROUND

Several studies on clinical practice for Duchenne muscular dystrophy (DMD) have been conducted in Western countries. However, there have been only a few similar studies in Asia and Oceania. Here, we investigate the steroid therapy-related clinical practice for DMD among the local experts. In 2015, we conducted a DMD expert survey in Asia and Oceania to acquire information regarding patients with DMD and to assess current clinical practice with the cooperation of Asian and Oceanian Myology Centre, a neuromuscular disease research network.

RESULTS

We obtained survey responses from 87 out of 148 clinicians (62%) from 13 countries and regions. In China, 1385 DMD patients were followed-up by 5 respondent neurologists, and 84% were between 0 and 9 years of age (15% were 10-19 years, 1% > 19 years). While in Japan, 1032 patients were followed-up by 20 clinicians, and the age distribution was similar between the 3 groups (27% were 0-9 years, 35% were 10-19 years, 38% were >19 years). Most respondent clinicians (91%) were aware of DMD standard of care recommendations. Daily prednisolone/prednisone administration was used most frequently at initiation (N = 45, 64%). Inconsistent opinion on steroid therapy after loss of ambulation and medication for bone protection was observed.

CONCLUSIONS

Rare disease research infrastructures have been underdeveloped in many of Asian and Oceanian countries. In this situation, our results show the snapshots of current medical situation and clinical practice in DMD. For further epidemiological studies, expansion of DMD registries is necessary.

Exploring the Interface between Inflammatory and Therapeutic Glucocorticoid Induced Bone and Muscle Loss

Due to their potent immunomodulatory anti-inflammatory properties, synthetic glucocorticoids (GCs) are widely utilized in the treatment of chronic inflammatory disease. In this review, we examine our current understanding of how chronic inflammation and commonly used therapeutic GCs interact to regulate bone and muscle metabolism. Whilst both inflammation and therapeutic GCs directly promote systemic osteoporosis and muscle wasting, the mechanisms whereby they achieve this are distinct. Importantly, their interactions in vivo are greatly complicated secondary to the directly opposing actions of GCs on a wide array of pro-inflammatory signalling pathways that underpin catabolic and anti-anabolic metabolism. Several clinical studies have attempted to address the net effects of therapeutic glucocorticoids on inflammatory bone loss and muscle wasting using a range of approaches. These have yielded a wide array of results further complicated by the nature of inflammatory disease, underlying the disease management and regimen of GC therapy. Here, we report the latest findings related to these pathway interactions and explore the latest insights from murine models of disease aimed at modelling these processes and delineating the contribution of pre-receptor steroid metabolism. Understanding these processes remains paramount in the effective management of patients with chronic inflammatory disease.

Comparison of Pulmonary Function Decline in Steroid-Treated and Steroid-Naïve Patients with Duchenne Muscular Dystrophy

OBJECTIVE

To describe and compare the lung function decline in patients with Duchenne muscular dystrophy on glucocorticoid therapy in contrast with glucocorticoid-naïve patients, and to define the deciles of pulmonary decline in glucocorticoid-treated patients.

STUDY DESIGN

This retrospective study examined lung function of patients with Duchenne muscular dystrophy over 6 years of age followed between 2001 and 2015 at 2 centers-glucocorticoid-treated patients in Cincinnati, Ohio, and glucocorticoid-naïve patients in Paris, France. Forced vital capacity (FVC, FVC%), forced expiratory volume in 1 second, maximal inspiratory pressure, maximal expiratory pressure, and peak expiratory flow data were analyzed. Only FVC data were available for the French cohort.

RESULTS

There were 170 glucocorticoid-treated patients (92%), 5 patients (2.7%) with past glucocorticoid use, and 50 French glucocorticoid-naïve patients. The peak absolute FVC was higher and was achieved at earlier ages in glucocorticoid-treated compared with glucocorticoid-naïve patients (peak FVC, 2.4 ± 0.6 L vs 1.9 ± 0.7 L; P < .0001; ages 13.5 ± 3.0 years vs 14.3 ± 2.8 years; P = .03). The peak FVC% was also higher and was achieved at earlier ages in glucocorticoid-treated patients (peak FVC%, 105.1 ± 25.1% vs 56 ± 20.9%; P < .0001; ages 11.9 ± 2.9 years vs 13.6 ± 3.2 years; P = .002). Rates of decline for both groups varied with age. Maximal rates of decline were 5.0 ± 0.26% per year (12-20 years) for glucocorticoid-treated and 5.1 ± 0.39% per year for glucocorticoid-naïve patients (11-20 years; P = .2). Deciles of FVC% decline in glucocorticoid-treated patients show that patients experience accelerated decline at variable ages.

CONCLUSIONS

These data describe nonlinear rates of decline of pulmonary function in patients with Duchenne muscular dystrophy, with improved function in glucocorticoid-treated patients. FVC% deciles may be a useful tool for clinical and research use.

Human Galectin-1 Improves Sarcolemma Stability and Muscle Vascularization in the mdx Mouse Model of Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is a devastating disease caused by mutations in the dystrophin gene that result in the complete absence of dystrophin protein. We have shown previously that recombinant mouse Galectin-1 treatment improves physiological and histological outcome measures in the mdx mouse model of DMD. Because recombinant human Galectin-1 (rHsGal1) will be used to treat DMD patients, we performed a dose-ranging study and intraperitoneal or intravenous delivery to determine the efficacy of rHsGal1 to improve preclinical outcome measures in mdx mice. Our studies showed that the optimal dose of rHsGal1 delivered intraperitoneally was 20 mg/kg and that this treatment improved muscle strength, sarcolemma stability, and capillary density in skeletal muscle. We next examined the efficacy of intravenous delivery and found that a dose of 2.5 mg/kg rHsGal1 was well tolerated and improved outcome measures in the mdx mouse model. Our studies identified that intravenous doses of rHsGal1 exceeding 2.5 mg/kg resulted in toxicity, indicating that dosing using this delivery mechanism will need to be carefully monitored. Our results support the idea that rHsGal1 treatment can improve outcome measures in the mdx mouse model and support further development as a potential therapeutic agent for DMD.

Increased Number of Circulating CD8/CD26 T Cells in the Blood of Duchenne Muscular Dystrophy Patients Is Associated with Augmented Binding of Adenosine Deaminase and Higher Muscular Strength Scores

Duchenne muscular dystrophy (DMD) is an X-linked disorder that leads to cardiac and skeletal myopathy. The complex immune activation in boys with DMD is incompletely understood. To better understand the contribution of the immune system into the progression of DMD, we performed a systematic characterization of immune cell subpopulations obtained from peripheral blood of DMD subjects and control donors. We found that the number of CD8 cells expressing CD26 (also known as adenosine deaminase complexing protein 2) was increased in DMD subjects compared to control. No differences, however, were found in the levels of circulating factors associated with pro-inflammatory activation of CD8/CD26 cells, such as tumor necrosis factor-α (TNFα), granzyme B, and interferon-γ (IFNγ). The number of CD8/CD26 cells correlated directly with quantitative muscle testing (QMT) in DMD subjects. Since CD26 mediates binding of adenosine deaminase (ADA) to the T cell surface, we tested ADA-binding capacity of CD8/CD26 cells and the activity of bound ADA. We found that mononuclear cells (MNC) obtained from DMD subjects with an increased number of CD8/CD26 T cells had a greater capacity to bind ADA. In addition, these MNC demonstrated increased hydrolytic deamination of adenosine to inosine. Altogether, our data demonstrated that (1) an increased number of circulating CD8/CD26 T cells is associated with preservation of muscle strength in DMD subjects, and (2) CD8/CD26 T cells from DMD subjects mediated degradation of adenosine by adenosine deaminase. These results support a role for T cells in slowing the decline in skeletal muscle function, and a need for further investigation into contribution of CD8/CD26 T cells in the regulation of chronic inflammation associated with DMD.

ECM-Related Myopathies and Muscular Dystrophies: Pros and Cons of Protein Therapies

Extracellular matrix (ECM) myopathies and muscular dystrophies are a group of genetic diseases caused by mutations in genes encoding proteins that provide critical links between muscle cells and the extracellular matrix. These include structural proteins of the ECM, muscle cell receptors, enzymes, and intracellular proteins. Loss of adhesion within the myomatrix results in progressive muscle weakness. For many ECM muscular dystrophies, symptoms can occur any time after birth and often result in reduced life expectancy. There are no cures for the ECM-related muscular dystrophies and treatment options are limited to palliative care. Several therapeutic approaches have been explored to treat muscular dystrophies including gene therapy, gene editing, exon skipping, embryonic, and adult stem cell therapy, targeting genetic modifiers, modulating inflammatory responses, or preventing muscle degeneration. Recently, protein therapies that replace components of the defective myomatrix or enhance muscle and/or extracellular matrix integrity and function have been explored. Preclinical studies for many of these biologics have been promising in animal models of these muscle diseases. This review aims to summarize the ECM muscular dystrophies for which protein therapies are being developed and discuss the exciting potential and possible limitations of this approach for treating this family of devastating genetic muscle diseases. © 2017 American Physiological Society. Compr Physiol 7:1519-1536, 2017.

Developing standardized corticosteroid treatment for Duchenne muscular dystrophy

Despite corticosteroids being the only treatment documented to improve strength and function in boys with Duchenne muscular dystrophy (DMD) corticosteroid prescription is inconsistent and in some countries, corticosteroids are not prescribed. We are conducting a clinical trial that (1) compares the 3 most frequently prescribed corticosteroid regimes; (2) standardizes treatment of DMD complications; and (3) standardizes prevention of corticosteroid side effects. Investigators at 38 sites in 5 countries plan to recruit 300 boys aged 4-7 who are randomly assigned to one of three regimens: daily prednisone; daily deflazacort; or intermittent prednisone (10days on/10days off). Boys are followed for a minimum of 3years to assess the relative effectiveness and adverse event profiles of the different regimens. The primary outcome is a 3-dimensional variable consisting of log-transformed time to rise from the floor, forced vital capacity, and subject/parent satisfaction with treatment, each averaged over all post-baseline visits. The study protocol includes evidence- and consensus-based treatment of DMD complications and of corticosteroid side effects. This study seeks to establish a standard corticosteroid regimen for DMD. Since all new interventions for DMD are being developed as add-on therapies to corticosteroids, defining the optimum regimen is of importance for all new treatments.

Systematic Review of the Toxicity of Long-Course Oral Corticosteroids in Children

Background

Long courses of oral corticosteroids are commonly used in children in the management of chronic conditions. Various adverse drug reactions (ADRs) are known to occur with their use. This systematic review aimed to identify the most common and serious ADRs and to determine their relative risk levels.

Methods

A literature search of Embase, Medline, International Pharmaceutical Abstracts, CINAHL, Cochrane Library and PubMed was performed with no language restrictions in order to identify studies where oral corticosteroids were administered to patients aged 28 days to 18 years of age for at least 15 days of treatment. Each database was searched from their earliest dates to January 2016. All studies providing clear information on ADRs were included.

Results

One hundred and one studies including 33 prospective cohort studies; 21 randomised controlled trials; 21 case series and 26 case reports met the inclusion criteria. These involved 6817 children and reported 4321 ADRs. The three ADRs experienced by the highest number of patients were weight gain, growth retardation and Cushingoid features with respective incidence rates of 21.1%, 18.1% and 19.4% of patients assessed for these ADRs. 21.5% of patients measured showed decreased bone density and 0.8% of patients showed osteoporosis. Biochemical HPA axis suppression was detected in 269 of 487 patients where it was measured. Infection was the most serious ADR, with twenty one deaths. Varicella zoster was the most frequent infection (9 deaths).

Conclusions

Weight gain, growth retardation and Cushingoid features were the most frequent ADRs seen when long-course oral corticosteroids were given to children. Increased susceptibility to infection was the most serious ADR.

11β-Hydroxysteroid dehydrogenase type 1 within muscle protects against the adverse effects of local inflammation

Muscle wasting is a common feature of inflammatory myopathies. Glucocorticoids (GCs), although effective at suppressing inflammation and inflammatory muscle loss, also cause myopathy with prolonged administration. 11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) is a bidirectional GC-activating enzyme that is potently upregulated by inflammation within mesenchymal-derived tissues. We assessed the regulation of this enzyme with inflammation in muscle, and examined its functional impact on muscle. The expression of 11β-HSD1 in response to proinflammatory stimuli was determined in a transgenic murine model of chronic inflammation (TNF-Tg) driven by overexpression of tumour necrosis factor (TNF)-α within tissues, including muscle. The inflammatory regulation and functional consequences of 11β-HSD1 expression were examined in primary cultures of human and murine myotubes and human and murine muscle biopsies ex vivo. The contributions of 11β-HSD1 to muscle inflammation and wasting were assessed in vivo with the TNF-Tg mouse on an 11β-HSD1 null background. 11β-HSD1 was significantly upregulated within the tibialis anterior and quadriceps muscles from TNF-Tg mice. In human and murine primary myotubes, 11β-HSD1 expression and activity were significantly increased in response to the proinflammatory cytokine TNF-α (mRNA, 7.6-fold, p < 0.005; activity, 4.1-fold, p < 0.005). Physiologically relevant levels of endogenous GCs activated by 11β-HSD1 suppressed proinflammatory cytokine output (interkeukin-6, TNF-α, and interferon-γ), but had little impact on markers of muscle wasting in human myotube cultures. TNF-Tg mice on an 11β-11β-HSD1 knockout background developed greater muscle wasting than their TNF-Tg counterparts (27.4% less; p < 0.005), with smaller compacted muscle fibres and increased proinflammatory gene expression relative to TNF-Tg mice with normal 11β-HSD1 activity. This study demonstrates that inflammatory stimuli upregulate 11β-HSD1 expression and GC activation within muscle. Although concerns have been raised that excess levels of GCs may be detrimental to muscle, in this inflammatory TNF-α-driven model, local endogenous GC activation appears to be an important anti-inflammatory response that protects against inflammatory muscle wasting in vivo. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Long-term outcomes of steroid therapy for Duchenne muscular dystrophy in Japan

INTRODUCTION

Corticosteroids are effective for improving motor function in patients with Duchenne muscular dystrophy (DMD), but there is no consensus on a regimen that balances efficacy and side effects.

METHODS

Data from three groups of DMD patients were retrospectively analyzed: those treated with 0.75mg/kg/day prednisolone every day (daily group, n=51); those treated with 1mg/kg/day prednisolone on alternate days (intermittent group, n=36), and those not treated with steroids (nontreatment group, n=42).

RESULTS

Although the age of ambulation loss did not differ significantly among the groups, the hazard ratios for ambulation loss relative to the nontreatment group were 0.24 (95% confidence interval [CI]: 0.11-0.54) in the daily group and 0.34 (95% CI: 0.19-0.62) in the intermittent group. The percentage of predicted forced vital capacity increased until 9.6years of age (to 94.1%) in the daily group, until 8.8years of age (to 96.9%) in the intermittent group, and until 7.2years of age (to 87.6%) in the nontreatment group. Weight gain was the most frequently observed side effect in the treated groups. Height was significantly lower in the daily than in the nontreatment group. Other side effects were observed, but no patient discontinued therapy. There were no marked differences in benefits and side effects between the two treated groups.

DISCUSSION

This is the first assessment of long-term outcomes of different steroid therapy regimens in Japanese DMD patients. Benefits and side effects, except height, did not differ significantly between steroid regimens.

Efficacy and safety of deflazacort vs prednisone and placebo for Duchenne muscular dystrophy

Objective:

To assess safety and efficacy of deflazacort (DFZ) and prednisone (PRED) vs placebo in Duchenne muscular dystrophy (DMD).

Methods:

This phase III, double-blind, randomized, placebo-controlled, multicenter study evaluated muscle strength among 196 boys aged 5–15 years with DMD during a 52-week period. In phase 1, participants were randomly assigned to receive treatment with DFZ 0.9 mg/kg/d, DFZ 1.2 mg/kg/d, PRED 0.75 mg/kg/d, or placebo for 12 weeks. In phase 2, placebo participants were randomly assigned to 1 of the 3 active treatment groups. Participants originally assigned to an active treatment continued that treatment for an additional 40 weeks. The primary efficacy endpoint was average change in muscle strength from baseline to week 12 compared with placebo. The study was completed in 1995.

Results:

All treatment groups (DFZ 0.9 mg/kg/d, DFZ 1.2 mg/kg/d, and PRED 0.75 mg/kg/d) demonstrated significant improvement in muscle strength compared with placebo at 12 weeks. Participants taking PRED had significantly more weight gain than placebo or both doses of DFZ at 12 weeks; at 52 weeks, participants taking PRED had significantly more weight gain than both DFZ doses. The most frequent adverse events in all 3 active treatment arms were Cushingoid appearance, erythema, hirsutism, increased weight, headache, and nasopharyngitis.

Conclusions:

After 12 weeks of treatment, PRED and both doses of DFZ improved muscle strength compared with placebo. Deflazacort was associated with less weight gain than PRED.

Classification of evidence:

This study provides Class I evidence that for boys with DMD, daily use of either DFZ and PRED is effective in preserving muscle strength over a 12-week period.

Trends in steroid therapy for Duchenne muscular dystrophy in Japan

Introduction: We conducted a study to reveal trends in steroid prescription for Duchenne muscular dystrophy (DMD) patients in Japan. Methods: We asked patients (ages 5–20 years) identified in the patient registry and their clinicians about steroid therapy experiences. Regimen, dose, and starting age were compared among 3 subgroups according to prednisolone initiation year (2000–2004, 2005–2009, and 2010–2013). Results: Among 157 prednisolone users, 4 different regimens were used. Dose frequencies were: every other day (98 patients), daily (44 patients), 10 days on 20 days off (14 patients), and weekly (1 patient). Median starting age was 6 years, and median dose was 0.42 mg/kg/day. There was an increase in daily regimen use from 2005–2009 (n = 9, 16%) to 2010–2013 (n = 33, 36%). Conclusions: This study revealed a transition over time in steroid use from expert opinion to evidence‐based recommendation. Clinical research should be encouraged to optimize medication worldwide. Muscle Nerve54: 673–680, 2016

Practice guideline update summary: Corticosteroid treatment of Duchenne muscular dystrophy: Report of the Guideline Development Subcommittee of the American Academy of Neurology

OBJECTIVE

To update the 2005 American Academy of Neurology (AAN) guideline on corticosteroid treatment of Duchenne muscular dystrophy (DMD).

METHODS

We systematically reviewed the literature from January 2004 to July 2014 using the AAN classification scheme for therapeutic articles and predicated recommendations on the strength of the evidence.

RESULTS

Thirty-four studies met inclusion criteria.

RECOMMENDATIONS

In children with DMD, prednisone should be offered for improving strength (Level B) and pulmonary function (Level B). Prednisone may be offered for improving timed motor function (Level C), reducing the need for scoliosis surgery (Level C), and delaying cardiomyopathy onset by 18 years of age (Level C). Deflazacort may be offered for improving strength and timed motor function and delaying age at loss of ambulation by 1.4-2.5 years (Level C). Deflazacort may be offered for improving pulmonary function, reducing the need for scoliosis surgery, delaying cardiomyopathy onset, and increasing survival at 5-15 years of follow-up (Level C for each). Deflazacort and prednisone may be equivalent in improving motor function (Level C). Prednisone may be associated with greater weight gain in the first years of treatment than deflazacort (Level C). Deflazacort may be associated with a greater risk of cataracts than prednisone (Level C). The preferred dosing regimen of prednisone is 0.75 mg/kg/d (Level B). Over 12 months, prednisone 10 mg/kg/weekend is equally effective (Level B), with no long-term data available. Prednisone 0.75 mg/kg/d is associated with significant risk of weight gain, hirsutism, and cushingoid appearance (Level B).

Corticosteroid Treatment and Growth Patterns in Ambulatory Males with Duchenne Muscular Dystrophy

OBJECTIVES

To evaluate growth patterns of ambulatory males with Duchenne muscular dystrophy (DMD) treated with corticosteroids compared with ambulatory, steroid-naïve males with DMD and age-matched unaffected general-population males and to test associations between growth and steroid treatment patterns among treated males.

STUDY DESIGN

Using data from the Muscular Dystrophy Surveillance, Tracking, and Research Network, we identified a total of 1768 height, 2246 weight, and 1755 body mass index (BMI) measurements between age 2 and 12 years for 324 ambulatory males who were treated with corticosteroids for at least 6 months. Growth curve comparisons and linear mixed-effects modeling, adjusted for race/ethnicity and birth year, were used to evaluate growth and steroid treatment patterns (age at initiation, dosing interval, duration, cumulative dose).

RESULTS

Growth curves for ambulatory males treated with corticosteroids showed significantly shorter stature, heavier weight, and greater BMI compared with ambulatory, steroid-naïve males with DMD and general-population US males. Adjusted linear mixed-effects models for ambulatory males treated with corticosteroids showed that earlier initiation, daily dosing, longer duration, and greater dosages predicted shorter stature with prednisone. Longer duration and greater dosages predicted shorter stature for deflazacort. Daily prednisone dosing predicted lighter weight, but longer duration, and greater dosages predicted heavier weight. Early initiation, less than daily dosing, longer duration, and greater doses predicted greater BMIs. Deflazacort predicted shorter stature, but lighter weight, compared with prednisone.

CONCLUSION

Prolonged steroid use is significantly associated with short stature and heavier weight. Growth alterations associated with steroid treatment should be considered when making treatment decisions for males with DMD.

Corticosteroids for the treatment of Duchenne muscular dystrophy

BACKGROUND

Duchenne muscular dystrophy (DMD) is the most common muscular dystrophy of childhood. Untreated, this incurable disease, which has an X-linked recessive inheritance, is characterised by muscle wasting and loss of walking ability, leading to complete wheelchair dependence by 13 years of age. Prolongation of walking is a major aim of treatment. Evidence from randomised controlled trials (RCTs) indicates that corticosteroids significantly improve muscle strength and function in boys with DMD in the short term (six months), and strength at two years (two-year data on function are very limited). Corticosteroids, now part of care recommendations for DMD, are largely in routine use, although questions remain over their ability to prolong walking, when to start treatment, longer-term balance of benefits versus harms, and choice of corticosteroid or regimen.We have extended the scope of this updated review to include comparisons of different corticosteroids and dosing regimens.

OBJECTIVES

To assess the effects of corticosteroids on prolongation of walking ability, muscle strength, functional ability, and quality of life in DMD; to address the question of whether benefit is maintained over the longer term (more than two years); to assess adverse events; and to compare efficacy and adverse effects of different corticosteroid preparations and regimens.

SEARCH METHODS

On 16 February 2016 we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, EMBASE, CINAHL Plus, and LILACS. We wrote to authors of published studies and other experts. We checked references in identified trials, handsearched journal abstracts, and searched trials registries.

SELECTION CRITERIA

We considered RCTs or quasi-RCTs of corticosteroids (e.g. prednisone, prednisolone, and deflazacort) given for a minimum of three months to patients with a definite DMD diagnosis. We considered comparisons of different corticosteroids, regimens, and corticosteroids versus placebo.

DATA COLLECTION AND ANALYSIS

The review authors followed standard Cochrane methodology.

MAIN RESULTS

We identified 12 studies (667 participants) and two new ongoing studies for inclusion. Six RCTs were newly included at this update and important non-randomised cohort studies have also been published. Some important studies remain unpublished and not all published studies provide complete outcome data.

PRIMARY OUTCOME MEASURE

one two-year deflazacort RCT (n = 28) used prolongation of ambulation as an outcome measure but data were not adequate for drawing conclusions.

SECONDARY OUTCOME MEASURES

meta-analyses showed that corticosteroids (0.75 mg/kg/day prednisone or prednisolone) improved muscle strength and function versus placebo over six months (moderate quality evidence from up to four RCTs). Evidence from single trials showed 0.75 mg/kg/day superior to 0.3 mg/kg/day on most strength and function measures, with little evidence of further benefit at 1.5 mg/kg/day. Improvements were seen in time taken to rise from the floor (Gowers' time), timed walk, four-stair climbing time, ability to lift weights, leg function grade, and forced vital capacity. One new RCT (n = 66), reported better strength, function and quality of life with daily 0.75 mg/kg/day prednisone at 12 months. One RCT (n = 28) showed that deflazacort stabilised muscle strength versus placebo at two years, but timed function test results were too imprecise for conclusions to be drawn.One double-blind RCT (n = 64), largely at low risk of bias, compared daily prednisone (0.75 mg/kg/day) with weekend-only prednisone (5 mg/kg/weekend day), finding no overall difference in muscle strength and function over 12 months (moderate to low quality evidence). Two small RCTs (n = 52) compared daily prednisone 0.75 mg/kg/day with daily deflazacort 0.9 mg/kg/day, but study methods limited our ability to compare muscle strength or function.

ADVERSE EFFECTS

excessive weight gain, behavioural abnormalities, cushingoid appearance, and excessive hair growth were all previously shown to be more common with corticosteroids than placebo; we assessed the quality of evidence (for behavioural changes and weight gain) as moderate. Hair growth and cushingoid features were more frequent at 0.75 mg/kg/day than 0.3 mg/kg/day prednisone. Comparing daily versus weekend-only prednisone, both groups gained weight with no clear difference in body mass index (BMI) or in behavioural changes (low quality evidence for both outcomes, one study); the weekend-only group had a greater linear increase in height. Very low quality evidence suggested less weight gain with deflazacort than with prednisone at 12 months, and no difference in behavioural abnormalities. Data are insufficient to assess the risk of fractures or cataracts for any comparison.Non-randomised studies support RCT evidence in showing improved functional benefit from corticosteroids. These studies suggest sustained benefit for up to 66 months. Adverse effects were common, although generally manageable. According to a large comparative longitudinal study of daily or intermittent (10 days on, 10 days off) corticosteroid for a mean period of four years, a daily regimen prolongs ambulation and improves functional scores over the age of seven, but with a greater frequency of side effects than an intermittent regimen.

AUTHORS' CONCLUSIONS

Moderate quality evidence from RCTs indicates that corticosteroid therapy in DMD improves muscle strength and function in the short term (twelve months), and strength up to two years. On the basis of the evidence available for strength and function outcomes, our confidence in the effect estimate for the efficacy of a 0.75 mg/kg/day dose of prednisone or above is fairly secure. There is no evidence other than from non-randomised trials to establish the effect of corticosteroids on prolongation of walking. In the short term, adverse effects were significantly more common with corticosteroids than placebo, but not clinically severe. A weekend-only prednisone regimen is as effective as daily prednisone in the short term (12 months), according to low to moderate quality evidence from a single trial, with no clear difference in BMI (low quality evidence). Very low quality evidence indicates that deflazacort causes less weight gain than prednisone after a year's treatment. We cannot evaluate long-term benefits and hazards of corticosteroid treatment or intermittent regimens from published RCTs. Non-randomised studies support the conclusions of functional benefits, but also identify clinically significant adverse effects of long-term treatment, and a possible divergence of efficacy in daily and weekend-only regimens in the longer term. These benefits and adverse effects have implications for future research and clinical practice.

Assessment and management of respiratory function in patients with Duchenne muscular dystrophy: current and emerging options

Duchenne muscular dystrophy (DMD) is an X-linked myopathy resulting in progressive weakness and wasting of all the striated muscles including the respiratory muscles. The consequences are loss of ambulation before teen ages, cardiac involvement and breathing difficulties, the main cause of death. A cure for DMD is not currently available. In the last decades the survival of patients with DMD has improved because the natural history of the disease can be changed thanks to a more comprehensive therapeutic approach. This comprises interventions targeted to the manifestations and complications of the disease, particularly in the respiratory care. These include: 1) pharmacological intervention, namely corticosteroids and idebenone that significantly reduce the decline of spirometric parameters; 2) rehabilitative intervention, namely lung volume recruitment techniques that help prevent atelectasis and slows the rate of decline of pulmonary function; 3) scoliosis treatment, namely steroid therapy that is used to reduce muscle inflammation/degeneration and prolong ambulation in order to delay the onset of scoliosis, being an additional contribution to the restrictive lung pattern; 4) cough assisted devices that improve airway clearance thus reducing the risk of pulmonary infections; and 5) non-invasive mechanical ventilation that is essential to treat nocturnal hypoventilation, sleep disordered breathing, and ultimately respiratory failure. Without any intervention death occurs within the first 2 decades, however, thanks to this multidisciplinary therapeutic approach life expectancy of a newborn with DMD nowadays can be significantly prolonged up to his fourth decade. This review is aimed at providing state-of-the-art methods and techniques for the assessment and management of respiratory function in DMD patients.

Genetics and emerging treatments for Duchenne and Becker muscular dystrophy

Mutations in the DMD gene result in Duchenne or Becker muscular dystrophy due to absent or altered expression of the dystrophin protein. The more severe Duchenne muscular dystrophy typically presents around ages 2 to 5 with gait disturbance, and historically has led to the loss of ambulation by age 12. It is important for the practicing pediatrician, however, to be aware of other presenting signs, such as delayed motor or cognitive milestones, or elevated serum transaminases. Becker muscular dystrophy is milder, often presenting after age 5, with ambulation frequently preserved past 20 years and sometimes into late decades.

Online self-report data for duchenne muscular dystrophy confirms natural history and can be used to assess for therapeutic benefits

To assess the utility of online patient self-report outcomes in a rare disease, we attempted to observe the effects of corticosteroids in delaying age at fulltime wheelchair use in Duchenne muscular dystrophy (DMD) using data from 1,057 males from DuchenneConnect, an online registry. Data collected were compared to prior natural history data in regard to age at diagnosis, mutation spectrum, and age at loss of ambulation. Because registrants reported differences in steroid and other medication usage, as well as age and ambulation status, we could explore these data for correlations with age at loss of ambulation. Using multivariate analysis, current steroid usage was the most significant and largest independent predictor of improved wheelchair-free survival. Thus, these online self-report data were sufficient to retrospectively observe that current steroid use by patients with DMD is associated with a delay in loss of ambulation. Comparing commonly used steroid drugs, deflazacort prolonged ambulation longer than prednisone (median 14 years and 13 years, respectively). Further, use of Vitamin D and Coenzyme Q10, insurance status, and age at diagnosis after 4 years were also significant, but smaller, independent predictors of longer wheelchair-free survival. Nine other common supplements were also individually tested but had lower study power. This study demonstrates the utility of DuchenneConnect data to observe therapeutic differences, and highlights needs for improvement in quality and quantity of patient-report data, which may allow exploration of drug/therapeutic practice combinations impractical to study in clinical trial settings. Further, with the low barrier to participation, we anticipate substantial growth in the dataset in the coming years.

Administration of glucocorticoids in boys with Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is the most common neuromuscular disease affecting boys. Advances in their care can delay the progression of DMD-related disability and prolong survival. The administration of glucocorticoids is among these advances. Glucocorticoid therapy, however, is associated with a myriad of potential adverse effects, and treating physicians as well as patients and their family members must understand the benefit/risk ratio of glucocorticoid therapy. Although current best evidence supports the use of glucocorticoids in patients with DMD, many are not offered the option. Considerable variability in practice also exists regarding when and how these drugs should be administered.

The cooperative international neuromuscular research group Duchenne natural history study--a longitudinal investigation in the era of glucocorticoid therapy: design of protocol and the methods used

Contemporary natural history data in Duchenne muscular dystrophy (DMD) is needed to assess care recommendations and aid in planning future trials.

METHODS

The Cooperative International Neuromuscular Research Group (CINRG) DMD Natural History Study (DMD-NHS) enrolled 340 individuals, aged 2-28 years, with DMD in a longitudinal, observational study at 20 centers. Assessments obtained every 3 months for 1 year, at 18 months, and annually thereafter included: clinical history; anthropometrics; goniometry; manual muscle testing; quantitative muscle strength; timed function tests; pulmonary function; and patient-reported outcomes/health-related quality-of-life instruments.

RESULTS

Glucocorticoid (GC) use at baseline was 62% present, 14% past, and 24% GC-naive. In those ≥6 years of age, 16% lost ambulation over the first 12 months (mean age 10.8 years).

CONCLUSIONS

Detailed information on the study methodology of the CINRG DMD-NHS lays the groundwork for future analyses of prospective longitudinal natural history data. These data will assist investigators in designing clinical trials of novel therapeutics.

Corticosteroids in Duchenne muscular dystrophy: major variations in practice

INTRODUCTION

In 2004, a Cochrane Review and AAN practice parameter concluded that prednisone 0.75 mg/kg/day is of short-term efficacy in Duchenne muscular dystrophy (DMD). Subsequent efforts to standardize care for DMD indicated wide variation in corticosteroid use.

METHODS

We surveyed physicians who follow patients with DMD, including: (1) clinics in the TREAT-NMD (Translational Research in Europe-Assessment and Treatment of Neuromuscular Diseases) network (predominantly Europe) and (2) U.S. MDA clinic directors. We also documented the co-administered corticosteroids in a trial of a putative treatment (ataluren) for DMD.

RESULTS

Of 105 Treat-NMD clinicians, corticosteroids were not used in 10 clinics, and 29 different regimens were used--the most frequent 0.75 mg/kg/day prednisone (61 centers); 10 days on/10 days off (36 centers); 0.9 mg/kg/day deflazacort (32 centers); and 5 mg/kg/day on weekends (10 centers). Similar diversity was identified in MDA clinics and in the ataluren trial.

CONCLUSIONS

Variability in corticosteroid use suggests uncertainty about risks/benefits of corticosteroid regimens for DMD.

Novel approaches to corticosteroid treatment in Duchenne muscular dystrophy

Although prednisone has never been formally approved for use in Duchenne muscular dystrophy (DMD) by regulatory agencies, its efficacy has been confirmed in trials dating from the 1980s. There is a strong need for optimization of both specific type of glucocorticoid (eg, prednisone, vs deflazacort or others) and the dosing regimen. Ideally an optimized regimen would maximize efficacy while minimizing side-effect profiles. A new trial, FOR-DMD, aims to address this gap in knowledge. In parallel, there has been progress in the area of "dissociative steroids," drugs that are able to better separate efficacy and side effects, providing a broader therapeutic window.

The cooperative international neuromuscular research group Duchenne natural history study: glucocorticoid treatment preserves clinically meaningful functional milestones and reduces rate of disease progression as measured by manual muscle testing and other commonly used clinical trial outcome measures

introduction: Glucocorticoid (GC) therapy in Duchenne muscular dystrophy (DMD) has altered disease progression, necessitating contemporary natural history studies.

METHODS

The Cooperative Neuromuscular Research Group (CINRG) DMD Natural History Study (DMD-NHS) enrolled 340 DMD males, ages 2-28 years. A comprehensive battery of measures was obtained.

RESULTS

A novel composite functional "milestone" scale scale showed clinically meaningful mobility and upper limb abilities were significantly preserved in GC-treated adolescents/young adults. Manual muscle test (MMT)-based calculations of global strength showed that those patients <10 years of age treated with steroids declined by 0.4 ± 0.39 MMT unit/year, compared with -0.4 ± 0.39 MMT unit/year in historical steroid-naive subjects. Pulmonary function tests (PFTs) were relatively preserved in steroid-treated adolescents. The linearity and magnitude of decline in measures were affected by maturational changes and functional status.

CONCLUSIONS

In DMD, long-term use of GCs showed reduced strength loss and preserved functional capabilities and PFTs compared with previous natural history studies performed prior to the widespread use of GC therapy.

Idiopathic intracranial hypertension in a child with Duchenne muscular dystrophy

Duchenne muscular dystrophy is an X-linked, recessively inherited disorder characterized by progressive weakness attributable to the absence of dystrophin expression in muscle. In multiple studies, the chronic administration of corticosteroids slowed the loss of ambulation that develops in mid to late childhood. Corticosteroids, however, frequently produce unacceptable side effects, including Cushingoid appearance and weight gain. Deflazacort, an oxazoline analogue of prednisolone, produces equivalent benefits on muscle with fewer reported Cushingoid side effects. We present a 9-year-old boy with Duchenne muscular dystrophy who developed morbid obesity and subsequent idiopathic intracranial hypertension after 2 years of receiving deflazacort. Although deflazacort is typically thought to produce less obesity than prednisone, severe Cushingoid side effects may occur in some individuals. To our knowledge, this description is the first of idiopathic intracranial hypertension complicating chronic corticosteroid treatment of Duchenne muscular dystrophy.

Randomized, blinded trial of weekend vs daily prednisone in Duchenne muscular dystrophy

OBJECTIVE

To perform a double-blind, randomized study comparing efficacy and safety of daily and weekend prednisone in boys with Duchenne muscular dystrophy (DMD).

METHODS

A total of 64 boys with DMD who were between 4 and 10 years of age were randomized at 1 of 12 centers of the Cooperative International Neuromuscular Research Group. Efficacy and safety of 2 prednisone schedules (daily 0.75 mg/kg/day and weekend 10 mg/kg/wk) were evaluated over 12 months.

RESULTS

Equivalence was met for weekend and daily dosing of prednisone for the primary outcomes of quantitative muscle testing (QMT) arm score and QMT leg score. Secondary strength scores for QMT elbow flexors also showed equivalence between the 2 treatment groups. Overall side effect profiles of height and weight, bone density, cataract formation, blood pressure, and behavior, analyzed at 12 months, did not differ between weekend and daily dosing of prednisone.

CONCLUSIONS

Weekend dosing of prednisone is equally beneficial to the standard daily dosing of prednisone. Analysis of side effect profiles demonstrated overall tolerability of both dosing regimens.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that weekend prednisone dosing is as safe and effective as daily prednisone in preserving muscle strength and preventing body mass index increases in boys with DMD over a 12-month period.

Comparison of motor strength and function in patients with Duchenne muscular dystrophy with or without steroid therapy

OBJECTIVE

To compare muscle strength (MS) and motor function in patients with Duchenne muscular dystrophy (DMD) receiving steroids for different times against the natural evolution of DMD described by Scott et al.

METHOD

90 patients with DMD (aged 5- 12 years), receiving steroids for one to seven years, were evaluated by Medical Research Council Scale (MRC) and Hammersmith motor ability score. The relation between MS and motor abilities measurement from our data and Scott's ones were ascertained statistically.

RESULTS

The relation between patient's age and Hammersmith scores revealed decrease of 0.76 point per year for age against decrease of 2.23 points on Scott's study. The relation between MRC scale and patient's age showed decrease of 0.80 point per year of age against decrease of 3.65 points on Scott's study.

CONCLUSION

In patients with DMD aged five to 12 years the progression of the disease is delayed by steroids and the motor function is less reduced than muscular strength.

Relationship between clinical outcome measures and parent proxy reports of health-related quality of life in ambulatory children with Duchenne muscular dystrophy

In Duchenne muscular dystrophy, data directly linking changes in clinical outcome measures to patient-perceived well-being are lacking. This study evaluated the relationship between clinical outcome measures used in clinical trials of ambulatory Duchenne muscular dystrophy (Vignos functional grade, quantitative knee extension strength, timed functional performance measures, and gait velocity) and 2 health-related quality of life measures--the Pediatric Outcomes Data Collection Instrument and Pediatric Quality of Life Inventory-in 52 ambulatory Duchenne muscular dystrophy subjects and 36 controls. Those with the disease showed significant decrements in parent proxy-reported health-related quality of life measures versus controls across all domains. The Pediatric Outcomes Data Collection Instrument transfers/basic mobility and sports/ physical function and the Pediatric Quality of Life Inventory physical functioning domains had significant associations with age (and hence disease progression) and traditional clinical outcome measures employed in clinical trials of ambulatory boys with Duchenne muscular dystrophy. Selected domains of the Pediatric Outcomes Data Collection Instrument and generic Pediatric Quality of Life Inventory are potential patient-reported outcome measures for clinical trials in ambulatory individuals with the disease.

Change in natural history of Duchenne muscular dystrophy with long-term corticosteroid treatment: implications for management

In 2005, the American Academy of Neurology and the Child Neurology Society published a practice parameter, based primarily on studies that involved 6 to 18 months of treatment, indicating that prednisone has a beneficial effect on muscle strength and function in patients with Duchenne muscular dystrophy and recommended that corticosteroids be offered (prednisone 0.75 mg/kg/d and deflazacort 0.9 mg/kg/d) as treatment. Recent reports emphasize that longer term treatment with corticosteroids (greater than 3 years) produces important sustained benefits in neuromuscular function without causing major side effects. This review highlights these reports and indicates that long-term corticosteroid therapy (1) prolongs ambulation by 2 to 5 years, (2) reduces the need for spinal stabilization surgery, (3) improves cardiopulmonary function, (4) delays the need for noninvasive nasal ventilation, and (5) increases survival and the quality of life of patients with Duchenne muscular dystrophy. Educational, vocational, and other social counseling is now a vital part of management for Duchenne muscular dystrophy.

Aging with muscular dystrophy: pathophysiology and clinical management

Major advances in the fields of medical science and physiology, molecular genetics, biomedical engineering, and computer science have provided individuals with muscular dystrophy (MD) with more functional equipment, allowing better strategies for improvement of quality of life. These advances have also allowed a significant number of these patients to live much longer. As progress continues to change management, it also changes patients' expectations. A comprehensive medical and rehabilitative approach to management of aging MD patients can often fulfill expectations and help them enjoy an enhanced quality of life.

Duchenne muscular dystrophy: Canadian paediatric neuromuscular physicians survey

BACKGROUND

Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy in childhood.

METHOD

To assess the current care of paediatric DMD patients in Canada, a questionnaire was mailed to 17 physicians who were members of the Canadian paediatric neuromuscular group. Areas of enquiry included; 1) multidisciplinary team composition; 2) means of DMD diagnosis; 3) corticosteroid use; surveillance and management for: 4) orthopaedic, 5) respiratory and 6) cardiac complications and 7) health maintenance (nutrition & immunizations).

RESULTS

Completed surveys were returned by 14/17 (82%) of physicians. Twelve respondents followed DMD patients. All centres had multidisciplinary teams, including respirology (11/12), child neurology or physiatry (11), physiotherapy (9), occupational therapy (9) and orthopaedic surgery (7). Deflazacort 0.9 mg/kg/d was used at all centres, which was continued after loss of independent ambulation (11), along with routine calcium and vitamin D supplementation (10). Night splints were prescribed at all centres. Routine surveillance studies included pulmonary function testing (11), sleep studies (10), EKG/echocardiogram (10), bone density (DEXA) scans (10), spine radiography (9), and dietician referral (4).

CONCLUSION

Paediatric DMD patients are receiving relatively consistent care in multidisciplinary clinics across Canada, in accordance with recommended guidelines for DMD.

Interventions for increasing ankle range of motion in patients with neuromuscular disease

BACKGROUND

Reduced ankle dorsiflexion range of motion, or ankle equinus, is a common and disabling problem for patients with neuromuscular disease. Clinicians devote considerable time and resources implementing interventions to correct this problem although few of these interventions have been subject to rigorous empirical investigation.

OBJECTIVES

To assess the effect of interventions to reduce or resolve ankle equinus in people with neuromuscular disease.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Trials Specialized Register (August 2009), Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2009), MEDLINE (1966 to August 2009), EMBASE (1980 to August 2009), CINAHL 1982 to August 2009), AMED (1985 to August 2009) and The Physiotherapy Evidence Database (PEDro) (1929 to August 2009). We searched the reference lists of identified articles and also contacted known experts in the field to identify additional or unpublished data.

SELECTION CRITERIA

Randomised controlled trials evaluating interventions for increasing ankle dorsiflexion range of motion in neuromuscular disease. Outcomes included ankle dorsiflexion range of motion, functional improvement, foot alignment, foot and ankle muscle strength, health-related quality of life, satisfaction with the intervention and adverse events.

DATA COLLECTION AND ANALYSIS

Two authors independently selected papers, assessed trial quality and extracted data.

MAIN RESULTS

Four studies involving 149 participants met inclusion criteria for this review. Two studies assessed the effect of night splinting in a total of 26 children and adults with Charcot-Marie-Tooth disease type 1A. There were no statistically or clinically significant differences between wearing a night splint and not wearing a night splint. One study assessed the efficacy of prednisone treatment in 103 boys with Duchenne muscular dystrophy. While a daily dose of prednisone at 0.75 mg/kg/day resulted in significant improvements in some strength and function parameters compared with placebo, there was no significant difference in ankle range of motion between groups. Increasing the prednisone dose to 1.5 mg/kg/day had no significant effect on ankle range of motion. One study evaluated early surgery in 20 young boys with Duchenne muscular dystrophy. Surgery resulted in increased ankle dorsiflexion range at 12 months but functional outcomes favoured the control group. By 24 months, many boys in the surgical group experienced a relapse of achilles tendon contractures.

AUTHORS' CONCLUSIONS

There is no evidence of significant benefit from any intervention for increasing ankle range of motion in Charcot-Marie-Tooth disease type 1A or Duchenne muscular dystrophy. Further research is required.

Diagnosis and management of Duchenne muscular dystrophy, part 1: diagnosis, and pharmacological and psychosocial management

Duchenne muscular dystrophy (DMD) is a severe, progressive disease that affects 1 in 3600-6000 live male births. Although guidelines are available for various aspects of DMD, comprehensive clinical care recommendations do not exist. The US Centers for Disease Control and Prevention selected 84 clinicians to develop care recommendations using the RAND Corporation-University of California Los Angeles Appropriateness Method. The DMD Care Considerations Working Group evaluated assessments and interventions used in the management of diagnostics, gastroenterology and nutrition, rehabilitation, and neuromuscular, psychosocial, cardiovascular, respiratory, orthopaedic, and surgical aspects of DMD. These recommendations, presented in two parts, are intended for the wide range of practitioners who care for individuals with DMD. They provide a framework for recognising the multisystem primary manifestations and secondary complications of DMD and for providing coordinated multidisciplinary care. In part 1 of this Review, we describe the methods used to generate the recommendations, and the overall perspective on care, pharmacological treatment, and psychosocial management.

Delayed diagnosis in duchenne muscular dystrophy: data from the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet)

OBJECTIVE

To identify key factors for the delay in diagnosis of Duchenne muscular dystrophy (DMD) without known family history.

STUDY DESIGN

The cohort comes from the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet), a multistate, multiple-source, population-based surveillance system that identifies and gathers information on all cases of Duchenne and Becker muscular dystrophy born since 1982. We analyzed medical records of 453 Duchenne and Becker muscular dystrophy boys to document the time course and steps taken to reach a definitive diagnosis.

RESULTS

Among 156 boys without known family history of DMD prior to birth, first signs or symptoms were noted at a mean age of 2.5 years. Concerns resulted in primary care provider evaluation of the child at a mean age of 3.6 years. Mean age at time of initial creatine kinase was 4.7 years. Mean age at definitive diagnosis of DMD was 4.9 years.

CONCLUSIONS

There is a delay of about 2.5 years between onset of DMD symptoms and the time of definitive diagnosis, unchanged over the previous 2 decades. This delay results in lost opportunities for timely genetic counseling and initiation of corticosteroid treatment. We recommend checking creatine kinase early in the evaluation of boys with unexplained developmental delay.

Prednisone 10 days on/10 days off in patients with Duchenne muscular dystrophy

Corticosteroids are effective in improving motor function in Duchenne muscular dystrophy (DMD) patients within 6 months-2 years of treatment initiation, but there is as yet no consensus on which treatment scheme is the best. We retrospectively analyzed data of 35 DMD patients who were treated with prednisone 0.75 mg/kg per day intermittently 10 days on/10 days off. Prednisone was started during the ambulant phase at age 3.5-9.7 years (median 6.5 years). The median period of treatment was 27 months (range 3-123 months). The median age at which ambulation was lost was 10.8 years (mean 10.9 years; 95% confidence interval 10.0-11.8 years). Nine patients (26%) had excessive weight gain. Eight boys (21%) had a bone fracture, which was when four of these eight children lost the ability to walk. Treatment was stopped in two obese patients, two hyperactive boys and one patient following a fracture. Our data suggest that prednisone 10 on/10 off has relatively few side effects and extends the ambulant phase by 1 year compared to historical controls.

Approaching a new age in Duchenne muscular dystrophy treatment

Duchenne muscular dystrophy is the most common and severe form of muscular dystrophy. The cornerstones of current treatment include corticosteroids for skeletal muscle weakness, afterload reduction for cardiomyopathy, and noninvasive ventilation for respiratory failure. With these interventions, patients are walking and living longer. However, the current status is still far from adequate. Increased private and federal funding of studies in Duchenne muscular dystrophy has led to a large number of novel agents with propitious therapeutic potential. These include agents that modify dystrophin expression, increase muscle growth and regeneration, and modulate inflammatory responses. Many of these agents are already in clinical trials. Challenges to the development of additional novel therapeutics exist, including lack of validated animal models and lack of adequate biomarkers as surrogate endpoints. However, these challenges are not insurmountable and the next decade will likely see meaningful, new treatment options introduced into the clinical care of patients with Duchenne muscular dystrophy.