Health-Related Quality of Life in Patients with Adult-Onset Myotonic Dystrophy Type 1: A Systematic Review

Psychostimulants for hypersomnia (excessive daytime sleepiness) in myotonic dystrophy

BACKGROUND

Excessive daytime sleepiness is a common symptom of myotonic dystrophy. Psychostimulants are drugs that are increasingly used to treat hypersomnia in myotonic dystrophy.

OBJECTIVES

To assess the effects of psychostimulants in myotonic dystrophy patients with hypersomnia.

SEARCH METHODS

We searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and WHO ICTRP on 5 January 2023. We also checked the bibliographies of identified papers and made enquiries of the authors of the papers.

SELECTION CRITERIA

We considered all randomised controlled trials that have evaluated any type of psychostimulant (versus a placebo or no treatment) in children or adults with myotonic dystrophy, confirmed by clinical and electromyographic diagnostic, or genetic testing, and hypersomnia.

DATA COLLECTION AND ANALYSIS

Two review authors independently scrutinised potentially relevant papers for study inclusion, with any disagreements resolved by discussion. Two review authors independently performed data extraction. We obtained unpublished data from some study authors. We assessed the methodological quality of trials and applied GRADE to assess the certainty of evidence. Review authors did not contribute to eligibility or risk of bias assessment or data extraction of trials in which they had participated. When cross-over trials were included in the analysis, treatment effects were summarised as mean difference (MD) between treatment effects and standard error, and analysed by generic inverse variance.

MAIN RESULTS

We included six trials (136 participants). All studies included only adult outpatients, aged from 18 to 70 years old, and followed them only in the short term (up to four weeks). Five trials had a cross-over design. We judged five trials as being at low risk of bias. Primary outcome Data for mean improvement in the Maintenance of Wakefulness Test were available from three trials. The MD was 3.59 (95% confidence interval (CI) -0.06 to 7.24) minutes, and there was marked heterogeneity across studies (I2 = 71%). We downgraded the certainty of evidence to very low for inconsistency and imprecision. Secondary outcomes Data for mean improvement in the Epworth Sleepiness Scale were available from five trials. The MD was -2.55 (95% CI -4.00 to -1.11, P < 0.001) in favour of modafinil with considerable heterogeneity across studies (I2 = 80%). We downgraded the certainty of evidence to low for inconsistency. The effects of psychostimulants on excessive daytime sleepiness as assessed by the Multiple Sleep Latency Test (MD -1.82, 95% CI -5.57 to 1.93; P = 0.34; very low certainty evidence) and on quality of life (MD 1.27, 95% CI -3.63 to 6.17; I2 = 0%; very low certainty evidence) were very uncertain. The risk ratio for experiencing adverse events was 1.70 (95% CI 0.75 to 3.85; P = 0.20; I2 = 0%; low certainty evidence). No trial evaluated our primary or secondary outcomes in the long term. We were not able to perform planned subgroup analyses as none of the trials provided relevant data.

AUTHORS' CONCLUSIONS

In myotonic dystrophy, the effects of psychostimulants on excessive daytime sleepiness as assessed by the Maintenance of Wakefulness Test or Multiple Sleep Latency Test and on quality of life are very uncertain. Psychostimulants may improve hypersomnia as self-evaluated by the Epworth Sleepiness Scale and may increase the risk of adverse events. More randomised trials are needed to evaluate the efficacy and safety of psychostimulants in both the short and long term.

Expert Insights from a Delphi-driven Neurologists' Panel: Real-world Mexiletine use in Patients with Myotonic Disorders in Italy

Background

Myotonic disorders, such as non-dystrophic myotonias (NDMs) and myotonic dystrophies (DMs) are characterized by a delay in muscle relaxation after a contraction stimulus. There is general consensus that protocols to treat myotonia need to be implemented.

Objective

Mexiletine is the only pharmacological agent approved for the symptomatic treatment of myotonia in adult patients with NDM and is considered to be the first-line treatment for DMs; however, its production in Italy was halted in 2022 making its availability to patients problematic.

Methods

A panel of 8 Italian neurologists took part in a two-round Delphi panel between June and October 2022, analyzing the current use of mexiletine in Italian clinical practice.

Results

The panelists assist 1126 patients (69% DM type1, 18% NDM and 13% DM type2). Adult NDM patients receive, on average, 400-600 mg of mexiletine hydrochloride (HCl) while adult DM patients receive 100-600 mg, per day in the long-term. The severity of symptoms is considered the main reason to start mexiletine treatment for both NDM and DM patients. Mexiletine is reckoned to have a clinical impact for both NDM and DM patients, but currently drug access is problematic.

Conclusions

Mexiletine treatment is recognized to have a role in the reduction of the symptomatic burden for NDM and DM patients. Patient management could be improved by facilitating access to therapy and developing new drug formulations.

Myotonic dystrophy type 1 (Steinert disease): 29 years of experience at a tertiary pediatric hospital

BACKGROUND

Myotonic dystrophy type 1 (DM1) is a multisystemic disorder caused by the expansion of a noncoding triplet repeat.

METHODS

A cross-sectional study was performed to characterize pediatric patients with DM1 followed in a tertiary hospital over the last 29 years, comparing the congenital and the childhood/juvenile-onset forms.

RESULTS

Thirty-seven patients (59.5 % male) were included, with a median age at the latest assessment of 16.8 years and a median follow-up of 7.7 years. Eleven patients were lost to follow-up, and two died. Twenty-five had congenital DM1 (CDM1), and this form had significantly higher triplet repeat length, history of polyhydramnios, lower median age at diagnosis, and first and last assessment. Common symptoms included distal skeletal muscle weakness (75.7 %) and facial involvement (94.6 %), along with dysphonia/dysarthria (73.0 %) and myotonia (73.0 %). Delayed independent ambulation frequency was significantly higher for CDM1 cases. Skeletal deformities affected 54.1 %, with talipes equinovarus and scoliosis occurring exclusively in CDM1 patients. Cognitive deficit was present in 75.7 % of cases. Polysomnograms revealed seven cases of obstructive sleep apnea and two of hypoventilation. Noninvasive ventilation was used in nine cases, and three had recurrent respiratory infections. The cardiovascular system was affected in 21.6 % of cases. Gastrointestinal issues included constipation (24.3 %), feeding difficulties (16.2 %), and cholelithiasis (5.4 %). Cataracts, epilepsy, and diabetes mellitus were reported in two cases each.

CONCLUSION

Our study highlights the diverse spectrum of severity and multiorgan involvement of DM1 in pediatric patients. It underscores the importance of establishing a pediatric-specific standard of care to enhance health outcomes through comprehensive multidisciplinary management.

Care for capabilities: Implementing the capability approach in rehabilitation of patients with neuromuscular diseases. Study protocol of the controlled before-after ReCap-NMD study

Background

High quality care of patients with neuromuscular diseases requires a personalised approach that focuses on achieving and maintaining a level of functioning that enables them to be in a state of well-being. The capability approach states that well-being should be understood in terms of capabilities, the substantial opportunities that people have to be and do things they have reasons to value. In this Rehabilitation and Capability care for patients with Neuromuscular diseases (ReCap-NMD) study, we want to investigate whether providing care based on the capability approach (capability care) has an added value in the rehabilitation of patients with neuromuscular diseases (NMD).

Methods

Two groups of 30 adult patients with facioscapulohumeral muscular dystrophy or myotonic dystrophy type 1 will be included. The first group will receive rehabilitation care as usual with a follow-up period of 6 months. Then, based on theory, and experiences of patients and healthcare professionals, capability care will be developed. During the following 3 months, the multidisciplinary outpatient rehabilitation care team will be trained in providing this newly developed capability care. Subsequently, the second group will receive capability care, with a follow-up period of 6 months. A mixed methods approach is used with both qualitative and quantitative outcome measures to evaluate the effect of capability care and to perform a process evaluation. The primary outcome measure will be the Canadian Occupational Performance Measure.

Discussion

The ReCap-NMD study is the first study to design and implement a healthcare intervention based on the capability approach. The results of this study will expand our knowledge on how the capability approach can be applied in delivering and evaluating healthcare, and will show whether implementing such an intervention leads to a higher well-being for patients with NMD.

Trial registration

Registered at Trialregister.nl (Trial NL8946) on 12^th of October, 2020.

Understanding Symptoms in RYR1-Related Myopathies: A Mixed-Methods Analysis Based on Participants' Experience

BACKGROUND

In rare diseases such as ryanodine receptor 1-related myopathies (RYR1-RM), health-related quality of life (HRQoL) measures are critically important so clinicians and researchers can better understand what symptoms are most important to participants, with the ultimate goal of finding tangible solutions for them.

OBJECTIVES

The main objective of this study was to characterize symptoms in individuals with RYR1-RM to inform future research. A secondary objective of this study was to analyze positive and negative sentiments regarding symptoms and treatment effects post N-acetylcysteine (NAC) administration in individuals with RYR1-RM.

METHODS

The study used a mixed-methods design applying methodological triangulation. Qualitative data were collected via semi-structured interviews at three visits to characterize symptoms in individuals with RYR1-RM and to analyze treatment effects. Qualitative data were then transformed into quantitative results to measure the frequency with which each symptom was mentioned by participants.

RESULTS

A total of 12 symptoms were identified as areas of interest to participants with RYR1-RM, highlighting fatigue and weakness as key symptoms. Data transformation categorized more than 1000 citations, reporting a greater number of positive comments for postintervention interviews than for baseline and preintervention visits and that NAC group participants stated more positive comments regarding treatment effect than did the placebo group.

CONCLUSIONS

We present a comprehensive characterization of symptoms in RYR1-RM and how those symptoms influence HRQoL. Furthermore, the introduction of mixed methods may be a valuable way to better understand patient-centered data in rare diseases to support affected individuals in coping with their symptoms.

Change over time in ability to perform activities of daily living in myotonic dystrophy type 1

OBJECTIVE

The objective of this longitudinal, observational study was to investigate change over time in ability to perform activities of daily living in myotonic dystrophy type 1 (DM1).

METHODS

Adults with genetically confirmed DM1 were recruited as part of the PhenoDM1 study in the UK. Data on activities of daily living were recorded through the DM1-ActivC at baseline and a follow-up visit after 12 (± 3) months. A subset of patients had advanced genetic testing to determine the size of the progenitor allele.

RESULTS

Our sample comprised 150 patients with DM1 (mean age: 45 years; 52% female). Mean follow-up was 383 days. Mean DM1-ActivC total score at baseline was 71.24 (95% confidence interval 67.77-74.71) and at the follow-up visit 69.04 (65.54-72.54). Approximately 43% of patients had a lower score at the follow-up visit (indicating a decreased ability to perform activities of daily living), 24% a higher score (indicating an increased ability), and 33% the same score at baseline and follow-up. The mean annual change in the DM1-ActivC total score, estimated at - 2.06 (- 3.54 to - 0.59), was significantly related to patients' baseline score, but not sex, disease duration, timed test results, or cytosine-thymine-guanine repeat length.

CONCLUSIONS

Change over time in ability to perform activities of daily living as recorded through the DM1-ActivC varies substantially between patients with DM1. Our data contribute to the understanding of the natural evolution of the disease, and should be helpful to inform the design of future trials based on the DM1-ActivC.

How to capture activities of daily living in myotonic dystrophy type 2?

Myotonic dystrophy type 2 (DM2) lacks validated patients´ reported outcomes (PROs). This represents a limit for monitoring disease progression and perceived efficacy of symptomatic treatments. Our aim was to investigate whether PROs for activities of daily living designed for other neuromuscular diseases could be used in DM2. Sixty-six DM2 patients completed the following PROs: DM1-Activ-c, Rasch-built Pompe-specific activity (R-PAct) scale, McGill-pain questionnaire, fatigue and daytime sleepiness scale and Beck depression inventory (BDI-II). Clinical data and motor outcome measures (6-minutes walking test - 6MWT, manual muscle testing, quick motor function test and myotonia behavior scale) were collected as well. Patients underwent one visit at baseline and one after 10 months. Ceiling/flooring effects, criterion validity and discriminant validity were calculated. DM1-activ-c and R-PAct showed acceptable ceiling effects despite being built for myotonic dystrophy type 1 and Pompe disease, respectively. The difficulty hierarchy of the single items was better preserved in R-PAct than in DM1-Activ-c. Both tests showed excellent criterion validity highly correlating with 6MWT, quick motor function test, myalgia and disease duration. They could partially discriminate patients with different disability grades. These results suggest that DM1-Activ-c, slightly better than R-PAct, might be adopted for monitoring activities of daily living also in DM2, at least until disease-specific PROs will be available.

A population-based measure of chronic disease severity for health planning and evaluation in the United States

In the healthcare sector, patients can be categorized into clinical risk groups, which are based, in part, on multiple chronic conditions. Population-based measures of clinical risk groups for population health planning, however, are not available. Using responses of working-age adults (19-64 years old) from the Behavioral Risk Factor Surveillance System for survey years 2015-2017, a population-based measure of chronic disease severity (CDS) was developed as a proxy for clinical risk groups. Four categories of CDS were developed: low, medium-low, medium-high, and high, based on self-reported diagnoses of multiple chronic conditions, weighted by hospitalization costs. Prevalence estimates of CDS were prepared, by population demographics and state characteristics, and CDS association with perceived health-related quality of life (HRQOL) was evaluated. Age-adjusted CDS varied from 72.9% (95% CI: 72.7-73.1%) for low CDS, to 21.0% (95% CI: 20.8-21.2%), 4.4% (95% CI: 4.3-4.5%) and 1.7% (95% CI: 1.6-1.8%) for medium-low, medium-high, and high CDS, respectively. The prevalence of high CDS was significantly greater (p < 0.05) among older adults, those living below the federal poverty level, and those with disabilities. The adjusted odds of fair/poor perceived HRQOL among adults with medium-low or medium-high/high CDS were 2.39 times (95% CI: 2.30-2.48) or 6.53 times (95% CI: 6.22-6.86) higher, respectively, than adults with low CDS. Elevated odds of fair/poor HRQOL with increasing CDS coincided with less prevalence of high CDS among men, minority race/ethnicities, and adults without insurance, suggesting a link between CDS and risk of mortality. Prevalence of high CDS was significantly higher (p < 0.05) in states with lower population density, lower per capita income, and in states that did not adopt the ACA. These results demonstrate the relevance of a single continuous population-based measure of chronic disease severity for health planning at the state, regional, and national levels.