Effects and Acceptability of an Individualized Home-Based 10-Week Training Program in Adults with Myotonic Dystrophy Type 1

A Tailored Home-Based Training Program Improved Ataxia Severity and Participation in Adults With ARSACS

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a rare degenerative movement disorder impacting balance and mobility. Rehabilitation helps to reduce disease severity and increase the quality of life of people with ARSACS. However, rehabilitation programs require many trips to dedicated facilities, posing a significant challenge for individuals living with ARSACS. This study aimed to develop a home-based training program specific for adults with ARSACS and to document its effects on ataxia severity, balance, mobility, and participation. This non-blinded and non-randomised interventional study used a pre-post design with a control phase. The initial level of training difficulty was tailored to each participant using a standardized assessment tool. Participants trained three times a week for 12 weeks. Outcome measures included the BERG Balance Scale, Ottawa Sitting Scale, 10-meter Walk Test, 30-second Chair Stand Test, 10-Steps Test, LIFE-H, and Scale for the Assessment and Rating of Ataxia. The retrospective acceptability of the program was also assessed using Sekhon's theoretical framework of acceptability. Fourteen participants (eight walkers, 50% men) completed the program (self-reported attendance rate rate: 75-100%) and seven dropped out. All outcome measures remained stable during the control phase. Ataxia severity and participation significantly improved after the 12-week home-based training program. At an individual level, clinical improvements in standing and sitting balance were noted for almost half of the participants, particularly for non-walkers. The eight participants who assisted to the focus group reported that the program was acceptable. This study indicates that tailored home-based training is safe, acceptable, and helps to reduce ataxia severity and participation restriction for adults with ARSACS.

Physiotherapeutic Interventions for Patients With Rare Genetic Muscle-Wasting Disorders: A Systematic Review and Meta-Analysis

Patients with rare genetic muscle-wasting disorders (MWDs) often experience significant motor function impairments, making effective management strategies crucial for improving their quality of life. This systematic review and meta-analysis aimed to evaluate the impact of physiotherapeutic interventions on motor outcomes in this patient population.  A comprehensive literature search was conducted to identify randomized controlled trials (RCTs) and cohort-based studies that assessed physiotherapeutic interventions in patients with rare genetic MWDs. The primary outcome measure was the 6-minute walk test (6MWT). A random effects model was employed to calculate the mean difference (MD) and 95% confidence interval (CI).  Nine studies were selected for inclusion, and most demonstrated observable improvement in different facets of individuals with MWDs using physiotherapy. The meta-analysis of RCTs showed that physiotherapy statistically improved 6MWT performance (MD: -35.25 meters; 95% CI: -54.14 to -16.37) with low heterogeneity (Tau² = 0.00; Chi² = 0.48, df = 2, P = 0.79; I² = 0%). Similarly, the cohort-based studies demonstrated an overall MD (MD: -10.00; 95% CI: -11.07 to -8.93), with low heterogeneity (Tau² = 0.00; Chi² = 0.01, df = 1, P = 0.94; I² = 0%). Both analyses indicated significant improvements in 6MWT performance (RCTs: Z = 3.66, P = 0.0003; cohort-based: Z = 18.26, P < 0.00001). Physiotherapeutic interventions significantly enhanced motor function in patients with rare genetic MWDs, as evidenced by improved 6MWT performance. Exercise and intensive physiotherapy programs were particularly effective, although the benefits varied depending on the specific intervention and patient population. These findings support incorporating tailored physiotherapeutic strategies in MWD management to improve motor outcomes and overall quality of life.

Resistance training in women with myotonic dystrophy type 1: a multisystemic therapeutic avenue

Myotonic dystrophy type 1 (DM1) is a hereditary disease characterized by muscular impairments. Fundamental and clinical positive effects of strength training have been reported in men with DM1, but its impact on women remains unknown. We evaluated the effects of a 12-week supervised strength training on physical and neuropsychiatric health. Women with DM1 performed a twice-weekly supervised resistance training program (3 series of 6-8 repetitions of squat, leg press, plantar flexion, knee extension, and hip abduction). Lower limb muscle strength, physical function, apathy, anxiety and depression, fatigue and excessive somnolence, pain, and patient-reported outcomes were assessed before and after the intervention, as well as three and six months after completion of the training program. Muscle biopsies of the vastus lateralis were also taken before and after the training program to assess muscle fiber growth. Eleven participants completed the program (attendance: 98.5 %). Maximal hip and knee extension strength (p < 0.006), all One-Repetition Maximum strength measures (p < 0.001), apathy (p = 0.0005), depression (p = 0.02), pain interference (p = 0.01) and perception of the lower limb function (p = 0.003) were significantly improved by training. Some of these gains were maintained up to six months after the training program. Strength training is a good therapeutic strategy for women with DM1.

Effectiveness of conservative non-pharmacological interventions in people with muscular dystrophies: a systematic review and meta-analysis

INTRODUCTION

Management of muscular dystrophies (MD) relies on conservative non-pharmacological treatments, but evidence of their effectiveness is limited and inconclusive.

OBJECTIVE

To investigate the effectiveness of conservative non-pharmacological interventions for MD physical management.

METHODS

This systematic review and meta-analysis followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and searched Medline, CINHAL, Embase, AMED and Cochrane Central Register of Controlled Trial (inception to August 2022). Effect size (ES) and 95% Confidence Interval (CI) quantified treatment effect.

RESULTS

Of 31,285 identified articles, 39 studies (957 participants), mostly at high risk of bias, were included. For children with Duchenne muscular dystrophy (DMD), trunk-oriented strength exercises and usual care were more effective than usual care alone in improving distal upper-limb function, sitting and dynamic reaching balance (ES range: 0.87 to 2.29). For adults with Facioscapulohumeral dystrophy (FSHD), vibratory proprioceptive assistance and neuromuscular electrical stimulation respectively improved maximum voluntary isometric contraction and reduced pain intensity (ES range: 1.58 to 2.33). For adults with FSHD, Limb-girdle muscular dystrophy (LGMD) and Becker muscular dystrophy (BMD), strength-training improved dynamic balance (sit-to-stand ability) and self-perceived physical condition (ES range: 0.83 to 1.00). A multicomponent programme improved perceived exertion rate and gait in adults with Myotonic dystrophy type 1 (DM1) (ES range: 0.92 to 3.83).

CONCLUSIONS

Low-quality evidence suggests that strength training, with or without other exercise interventions, may improve perceived exertion, distal upper limb function, static and dynamic balance, gait and well-being in MD. Although more robust and larger studies are needed, current evidence supports the inclusion of strength training in MD treatment, as it was found to be safe.

Resistance Exercise Training Rescues Mitochondrial Dysfunction in Skeletal Muscle of Patients with Myotonic Dystrophy Type 1

BACKGROUND

Myotonic dystrophy type 1 (DM1) is a dominant autosomal neuromuscular disorder caused by the inheritance of a CTG triplet repeat expansion in the Dystrophia Myotonica Protein Kinase (DMPK) gene. At present, no cure currently exists for DM1 disease.

OBJECTIVE

This study investigates the effects of 12-week resistance exercise training on mitochondrial oxidative phosphorylation in skeletal muscle in a cohort of DM1 patients (n = 11, men) in comparison to control muscle with normal oxidative phosphorylation.

METHODS

Immunofluorescence was used to assess protein levels of key respiratory chain subunits of complex I (CI) and complex IV (CIV), and markers of mitochondrial mass and cell membrane in individual myofibres sampled from muscle biopsies. Using control's skeletal muscle fibers population, we classified each patient's fibers as having normal, low or high levels of CI and CIV and compared the proportions of fibers before and after exercise training. The significance of changes observed between pre- and post-exercise within patients was estimated using a permutation test.

RESULTS

At baseline, DM1 patients present with significantly decreased mitochondrial mass, and isolated or combined CI and CIV deficiency. After resistance exercise training, in most patients a significant increase in mitochondrial mass was observed, and all patients showed a significant increase in CI and/or CIV protein levels. Moreover, improvements in mitochondrial mass were correlated with the one-repetition maximum strength evaluation.

CONCLUSIONS

Remarkably, 12-week resistance exercise training is sufficient to partially rescue mitochondrial dysfunction in DM1 patients, suggesting that the response to exercise is in part be due to changes in mitochondria.

Multiple Case Study of Changes in Participation of Adults with Myotonic Dystrophy Type 1: Importance of Redesigning Accomplishment and Resilience

Background: Myotonic dystrophy type 1 (DM1) is the most prevalent adult form of neuromuscular disorders, for which a decrease of participation with age is known. However, little is known about facilitators and barriers to participation, especially from the perspective of both patients and caregivers. Objective: This study explored and explained changes in participation post-diagnosis with myotonic dystrophy type 1 from the perspective of six adults, their relatives and nurse case managers. Methods: A multiple case study was carried out with these triads (n =  6) using semi-structured individual interviews, medical charts, and a participation patient-reported outcome measure. The six cases were built around three women and three men (age: 40–56 years; disease duration: 19–39 years). Their “relatives” were mainly family members. Nurse case managers had done annual follow-ups with all the adults for approximately ten years. Changes in participation were characterized generally by: 1) heterogeneity, 2) insidious increase in restrictions, and more specifically by: 3) redesigning accomplishment, 4) progressive social isolation, 5) restrictions in life-space mobility, and 6) increasingly sedentary activities. Results: Important facilitators of participation were the adult’s resilience, highly meaningful activities, social support, living arrangement, and willingness to use technical aids. Barriers were mostly related to symptoms and a precarious social network, and were affected by misfit and potential syndemic interactions between personal (e.g., comorbidities) and environmental (e.g., stigma) factors. Conclusion: This study identified key facilitators and barriers and their underlying processes, which should be integrated into the evaluation and intervention framework to optimize participation over time.

Pharmacological and exercise-induced activation of AMPK as emerging therapies for myotonic dystrophy type 1 patients

Myotonic dystrophy type 1 (DM1) is a multisystemic disorder with variable clinical features. Currently, there is no cure or effective treatment for DM1. The disease is caused by an expansion of CUG repeats in the 3' UTR of DMPK mRNAs. Mutant DMPK mRNAs accumulate in nuclei as RNA foci and trigger an imbalance in the level and localization of RNA-binding proteins causing the characteristic missplicing events that account for the varied DM1 symptoms, a disease mechanism referred to as RNA toxicity. In recent years, multiple signalling pathways have been identified as being aberrantly regulated in skeletal muscle in response to the CUG expansion, including AMPK, a sensor of energy status, as well as a master regulator of cellular energy homeostasis. Converging lines of evidence highlight the benefits of activating AMPK signalling pharmacologically on RNA toxicity, as well as on muscle histology and function, in preclinical DM1 models. Importantly, a clinical trial with metformin, an activator of AMPK, resulted in functional benefits in DM1 patients. In addition, exercise, a known AMPK activator, has shown promising effects on RNA toxicity and muscle function in DM1 mice. Finally, clinical trials involving moderate-intensity exercise also induced functional benefits for DM1 patients. Taken together, these studies clearly demonstrate the molecular, histological and functional benefits of AMPK activation and exercise-based interventions on the DM1 phenotype. Despite these advances, several key questions remain; in particular, the extent of the true implication of AMPK in the observed beneficial improvements, as well as how, mechanistically, activation of AMPK signalling improves the DM1 pathophysiology.

The effects of 12 weeks' resistance training on psychological parameters and quality of life in adults with Facioscapulohumeral, Becker, and Limb-girdle dystrophies

PURPOSE

Investigate the impact of 12-weeks' moderate-intensity resistance training on psychological parameters in ambulatory adults with Facioscapulohumeral, Becker, and Limb-girdle muscular dystrophy.

METHODS

Seventeen adults with Facioscapulohumeral (n = 6), Limb-girdle (n = 6; types 2A, 2B, 2L, and 2I), or Becker (n = 5) muscular dystrophy took part. Participants were tested at baseline (PRE), after a 12-week control period (PRE2), and after a 12-week supervised resistance training programme (POST). Training included multi-joint and single-joint resistance exercises. Outcomes from self-report questionnaires were health-related quality of life, depressive symptoms, trait anxiety, self-esteem, and physical self-worth.

RESULTS

No difference in outcome measures, except depressive symptoms, was found in the control period (PRE to PRE2). Symptoms of depression were reduced by 9% from PRE to PRE2 (p < 0.05) and by a further 19% from PRE2 to POST (p < 0.05). Other changes from PRE2 to POST were that trait anxiety reduced by 10%, self-esteem increased by 10%, physical self-worth increased by 20%, and quality of life improved in 8 domains (p < 0.05).

CONCLUSION

These findings demonstrate the positive impact of moderate-intensity resistance training on psychological health and quality of life in adults with Facioscapulohumeral, Becker, and Limb-girdle muscular dystrophies.Implications for rehabilitationResistance training can have a positive impact on psychological health and quality of life in adults with Facioscapulohumeral, Becker, and Limb-girdle muscular dystrophy.Healthcare professionals should consider including moderate-intensity resistance training within the management and treatment programmes of adults with Facioscapulohumeral, Becker, and Limb-girdle muscular dystrophy.