Background and Objectives:Effective therapies for facioscapulohumeral muscular dystrophy (FSHD) are currently limited. Recombinant human growth hormone (rHGH) combined with testosterone (combination therapy) may have meaningful clinical effects on ambulation, strength, muscle mass, and disease burden. As such, combination therapy has the potential to limit disease progression and functional decline in individuals with muscular dystrophy. The objective of this study was to evaluate the safety, tolerability, and potential efficacy of combination therapy in adult men with FSHD. Methods:This investigator-initiated, single-center (University of Rochester), single-arm, proof-of-concept study evaluated the safety and tolerability of combination therapy in ambulatory adult men with FSHD. Participants received daily rHGH combined with testosterone enanthate injections every 2 weeks for 24 weeks, followed by a 12-week washout period. Participants underwent serial safety and laboratory assessments to monitor safety and tolerability during the study. Participants were also evaluated for changes from baseline in lean body mass (LBM) and fat mass, measured by dual-energy X-ray absorptiometry; ambulation, measured by 6-minute walk distance; strength; clinical function, measured using the FSHD-Composite Outcome Measure (FSHD-COM); and patient-reported disease burden, measured by the FSHD Health Index (FSHD-HI). Results:Nineteen of 20 participants completed the study, with no participants experiencing a serious adverse event. The most common adverse event was mild injection site reaction at the rHGH and/or testosterone injection site. After 24 weeks, LBM improved by 2.21 kilograms (95% CI 1.35-3.07; p < 0.0001), fat mass decreased by 1.30 kilograms (95% CI -2.56 to -0.04; p = 0.04), 6-minute walk distance increased by 37.3 m (95% CI 18.3-56.9; p = 0.001), overall strength (average % of predicted normal) increased by 3% (95% CI 0.3-5.6; p = 0.03), clinical function (FSHD-COM) improved by 2.4 points (95% CI 4.0-0.8; p = 0.006), and total disease burden (FSHD-HI) decreased by 6.1 points (95% CI -12.0 to -0.2; p = 0.04). Discussion:Combination therapy was safe and well tolerated in men with FSHD. Participants experienced improvements in ambulation, strength, muscle mass, and disease burden after receiving this study intervention. Larger randomized, double-blind, placebo-controlled trials are needed to further investigate this promising therapeutic approach. Trial Registration Information:Registered on ClinicalTrials.gov: NCT03123913.

Introduction/Aims Disease progression in myotonic dystrophy (DM) is marked by milestone events when functional thresholds are crossed. DM type 2 (DM2) is considered less severe than DM type 1 (DM1), but it is unknown whether this applies uniformly to all features. We compared the age-dependent risk for milestone events in DM1 and DM2 and tested for associations with age of onset and sex. Methods We studied a large cohort of adult participants in a national registry of DM1 and DM2. Using annual surveys from participants, we ascertained milestone events for motor involvement (use of cane, walker, ankle brace, wheelchair, or ventilatory device), systemic involvement (diabetes, pacemaker, cancer), loss of employment due to DM, and death. Results Mean follow-up of registry participants (929 DM1 and 222 DM2 patients) was 7 years. Disability and motor milestones occurred at earlier ages in DM1 than in DM2. In contrast, the risk of diabetes was higher and tended to occur earlier in DM2 (hazard ratio [HR], 0.56; P <= .001). In DM1, the milestone events tended to occur earlier, and life expectancy was reduced, when symptoms began at younger ages. In DM1, men were at greater risk for disability (HR, 1.34; P <= .01), use of ankle braces (HR, 1.41; P = .02), and diabetes (HR, 2.2; P <= .0001), whereas women were at greater risk for needing walkers (HR, 0.68; P = .001) or malignancy (HR, 0.66; P <= .01). Discussion Milestone events recorded through registries can be used to assess long-term impact of DM in large cohorts. Except for diabetes, the age-related risk of milestone events is greater in DM1 than in DM2.

Objective To assess mexiletine9s long-term safety and effect on 6-minute walk distance in a well-defined cohort of patients with myotonic dystrophy type 1 (DM1). Methods We performed a randomized, double-blind, placebo-controlled trial of mexiletine (150 mg 3 times daily) to evaluate its efficacy and safety in a homogenous cohort of adult ambulatory patients with DM1. The primary outcome was change in 6-minute walk distance at 6 months. Secondary outcomes included changes in hand grip myotonia, strength, swallowing, forced vital capacity, lean muscle mass, Myotonic Dystrophy Health Index scores, and 24-hour Holter and ECG results at 3 and 6 months. Results Forty-two participants were randomized and 40 completed the 6-month follow-up (n = 20 in both groups). No significant effects of mexiletine were observed on 6-minute walk distance, but hand grip myotonia was improved with mexiletine treatment. There were no differences between the mexiletine and placebo groups with respect to the frequency or type of adverse events. Changes in PR, QRS, and QTc intervals were similar in mexiletine- and placebo-treated participants. Conclusions There was no benefit of mexiletine on 6-minute walk distance at 6 months. Although mexiletine had a sustained positive effect on objectively measured hand grip myotonia, this was not seen in measures reflecting participants9 perceptions of their myotonia. No effects of mexiletine on cardiac conduction measures were seen over the 6-month follow-up period. Classification of Evidence This study provides Class I evidence that for ambulatory patients with DM1, mexiletine does not significantly change 6-minute walk distance at 6 months.

OBJECTIVE:To assess mexiletine's long-term safety and effect on 6-minute walk distance in a well-defined cohort of patients with myotonic dystrophy type 1 (DM1).METHODS:We performed a randomized, double-blind, placebo-controlled trial of mexiletine (150 mg 3 times daily) to evaluate its efficacy and safety in a homogenous cohort of adult ambulatory patients with DM1. The primary outcome was change in 6-minute walk distance at 6 months. Secondary outcomes included changes in hand grip myotonia, strength, swallowing, forced vital capacity, lean muscle mass, Myotonic Dystrophy Health Index scores, and 24-hour Holter and ECG results at 3 and 6 months.RESULTS:Forty-two participants were randomized and 40 completed the 6-month follow-up (n = 20 in both groups). No significant effects of mexiletine were observed on 6-minute walk distance, but hand grip myotonia was improved with mexiletine treatment. There were no differences between the mexiletine and placebo groups with respect to the frequency or type of adverse events. Changes in PR, QRS, and QTc intervals were similar in mexiletine- and placebo-treated participants.CONCLUSIONS:There was no benefit of mexiletine on 6-minute walk distance at 6 months. Although mexiletine had a sustained positive effect on objectively measured hand grip myotonia, this was not seen in measures reflecting participants' perceptions of their myotonia. No effects of mexiletine on cardiac conduction measures were seen over the 6-month follow-up period.CLASSIFICATION OF EVIDENCE:This study provides Class I evidence that for ambulatory patients with DM1, mexiletine does not significantly change 6-minute walk distance at 6 months.

Introduction: Recent evidence demonstrates that women with myotonic dystrophy type 1 are at increased risk of reproductive organ tumors. However, studies of reproductive cancer risk factors in those patients are lacking. Methods: Using questionnaires, we collected and analyzed personal history information related to cancer risk factors from women enrolled in a UK and US registry for myotonic dystrophy (dystrophia myotonica; DM) patients. Results: The survey was completed by 242 DM type 1 (DM1) and 44 DM type 2 (DM2) women enrolled in the UK Registry (N = 124) and the US National Registry (N = 162). The mean age at DM1 diagnosis was 33.8 years (standard deviation, SD = 13.2) and for DM2 was 49.2 (SD = 13.0). Mean age at survey was 48.7 (SD = 12.8) and 59.1 years (SD = 12.8) for DM1 and DM2, respectively. There were no statistically significant differences between DM1 and DM2 regarding menstrual history or fertility-related factors. Yet, women with DM2 were more likely to have used menopausal hormone therapy (HT) than women with DM1 (52.3 vs. 22.1%, p < 0.0001), and more women with DM2 had a hysterectomy (53.5 vs. 29.5%, p < 0.01). These differences were not statistically significant after age adjustment (OR = 2.00, p = 0.08, and OR = 1.40, p = 0.38, respectively). The frequency of self-reported reproductive organ tumors was not significantly different comparing DM1 to DM2 (p = 0.28). However, the data suggested that women with DM2 appear to have a lower risk of malignant tumors compared to those with DM1 (OR = 0.72, p = 0.69). Discussion: Our study is the first to characterize a wide range of reproductive risk factors in women with DM. We observed no significant differences between DM1 and DM2 in the factors that were evaluated, which suggests that the known excesses of ovarian and endometrial cancer previously reported in women with DM1 cannot be attributed to greater prevalence of standard cancer-related reproductive risk factors. Larger studies evaluating the possible link between reproductive cancer risk factors and risk of tumors in women with DM are needed.

Purpose of review Myotonic dystrophy type 2 (DM2) is a rare, progressive multisystem disease particularly affecting the skeletal muscle. A causal therapy is not yet available; however, prompt, appropriate symptomatic treatments are essential to limit disease-related complications. Evidence-based guidelines to assist medical practitioners in the care of DM2 patients do not exist. Recent findings The Myotonic Dystrophy Foundation (MDF) previously worked with an international group of 66 clinicians to develop consensus-based care recommendations for myotonic dystrophy type 1. Following a similar approach, the MDF recruited 15 international clinicians with long-standing experience in the care of DM2 patients to develop consensus-based care recommendations. The single text procedure was adopted. This process generated a 4-page Quick Reference Guide and a comprehensive 55-page document that provides care recommendations for DM2 patients. Summary The resulting recommendations will help standardize and improve care for DM2 patients and facilitate appropriate management in centers without neuromuscular specialists.

In the recently published consensus-based care recommendations for adults with myotonic dystrophy type 1 (DM1),1 visual symptoms caused by retinal dysfunction are not considered despite several studies reporting frequent abnormal electroretinograms (ERGs) in patients with DM1.2–4

The original version of this article [1] unfortunately included an error to an author's name. Author Jordi Díaz-Manera was erroneously presented as Jorge Alberto Diaz Manera. The correct author name has been included in the author list of this Correction article.

ABSTRACTIntroduction: When preparing for clinical trials in myotonic dystrophy type‐1 (DM1), it is important that researchers develop and identify patient‐reported outcome measures with good measurement properties. Methods: Fifty‐two DM1 patients enrolled in 2 clinical studies completed the Myotonic Dystrophy Health Index (MDHI), 36‐Item Short Form Health Survey (version 2; SF‐36v2), Individualized Neuromuscular Quality of Life questionnaire (INQoL), and a questionnaire comparing the relevance, usability, overall preference, and perceived responsiveness of each measure. The associations between instrument scores and physical function, genetic test results, and employment status were examined. Results: The MDHI was preferred over the INQoL in 13 of 13 areas and was preferred over the SF‐36v2 in 9 of 13 areas. The MDHI was the only score that was associated with participant employment status, CTG repeat length, and the 3 measurements of clinical function. Discussion: The MDHI correlates well with physical function and is viewed favorably by participants in DM1 clinical studies. Muscle Nerve 58: 49–55, 2018

OBJECTIVE:To analyze gastrointestinal (GI) manifestations, their progression over time, and medications being used to treat GI symptoms in a large cohort of patients with myotonic dystrophy types 1 (DM1) and 2 (DM2).METHODS:We analyzed patient-reported data and medical records in a national registry cohort at baseline and 5 years.RESULTS:At baseline, the majority of patients reported trouble swallowing in DM1 (55%; n = 499 of 913) and constipation in DM2 (53%; n = 96 of 180). Cholecystectomy occurred in 16.5% of patients with DM1 and 12.8% of patients with DM2, on average before 45 years of age. The use of medications indicated for gastroesophageal reflux disease was reported by 22.5% of DM1 and 18.9% of patients with DM2. Greater risk of a GI manifestation was associated with higher body mass index and longer disease duration in DM1 and female sex in DM2. At the 5-year follow-up, the most common new manifestations were trouble swallowing in patients with DM1 and constipation in patients with DM2.CONCLUSIONS:GI manifestations were common in both DM1 and DM2, with a relatively high frequency of gallbladder removal in DM1 and DM2 occurring at a younger age compared to normative data in the literature. Studies are needed to determine the pathomechanism of how sex, weight gain, and duration of disease contribute to GI manifestations and how these manifestations affect quality of life and clinical care for patients with DM1 and DM2.

Myotonic dystrophy (DM) and facioscapulohumeral muscular dystrophy (FSHD) are the two most common adult muscular dystrophies and have progressive and often disabling manifestations. Higher levels of medication adherence lead to better health outcomes, especially important to patients with DM and FSHD because of their multisystem manifestations and complexity of care. However, medication adherence has not previously been studied in a large cohort of DM type 1 (DM1), DM type 2 (DM2), and FSHD patients. The purpose of our study was to survey medication adherence and disease manifestations in patients enrolled in the NIH-supported National DM and FSHD Registry. The study was completed by 110 DM1, 49 DM2, and 193 FSHD patients. Notable comorbidities were hypertension in FSHD (44 %) and DM2 (37 %), gastroesophageal reflux disease in DM1 (24 %) and DM2 (31 %) and arrhythmias (29 %) and thyroid disease (20 %) in DM1. Each group reported high levels of adherence based on regimen complexity, medication costs, health literacy, side effect profile, and their beliefs about treatment. Only dysphagia in DM1 was reported to significantly impact medication adherence. Approximately 35 % of study patients reported polypharmacy (taking 6 or more medications). Of the patients with polypharmacy, the DM1 cohort was significantly younger (mean 55.0 years) compared to DM2 (59.0 years) and FSHD (63.2 years), and had shorter disease duration (mean 26 years) compared to FSHD (26.8 years) and DM2 (34.8 years). Future research is needed to assess techniques to ease pill swallowing in DM1 and to monitor polypharmacy and potential drug interactions in DM and FSHD.

AIM:The frequency and impact of symptoms experienced by patients with congenital, childhood, and juvenile-onset myotonic dystrophy (CDM/ChDM/JDM) is not documented. This report identifies symptomatic areas with the greatest disease burden in an international population of patients with early-onset myotonic dystrophy type-1 (DM1).METHOD:We distributed surveys to parents of patients with CDM/ChDM/JDM. Patients with CDM/ChDM/JDM were members of the US National Registry of DM1 Patients and Family Members, the Canadian Neuromuscular Disease Registry, or the Swedish Health System. Surveys inquired about 325 symptoms and 20 themes associated with CDM/ChDM/JDM. Parents identified the importance of each symptom and theme to their affected child. The prevalence of each symptom and theme were compared across subgroups of patients. The statistical analysis was performed using Fisher's exact and Kruskal-Wallis tests.RESULTS:One hundred and fifty parents returned surveys. The most frequently reported symptomatic themes in children were issues involving communication (81.7%) and problems with hands or fingers (79.6%). Problems with communication and fatigue were the issues that were reported to have the greatest impact on childrens' lives, while 24.1% of children reported cardiac disorders and 15.8% had problems with anesthesia.INTERPRETATION:A range of symptoms contribute to the burden of disease faced by children with DM1. Many of these symptoms are under-recognized.

Objective: To determine the frequency and relative importance of the most life-affecting symptoms in myotonic dystrophy type 2 (DM2) and to identify the factors that have the strongest association with these symptoms. Methods: We conducted a cross-sectional study of adult patients with DM2 from a National Registry of DM2 Patients to assess the prevalence and relative importance of 310 symptoms and 21 symptomatic themes. Participant responses were compared by age categories, sex, educational attainment, employment status, and duration of symptoms. Results: The symptomatic themes with the highest prevalence in DM2 were the inability to do activities (94.4%), limitations with mobility or walking (89.2%), hip, thigh, or knee weakness (89.2%), fatigue (89.2%), and myotonia (82.6%). Participants identified the inability to do activities and fatigue as the symptomatic themes that have the greatest overall effect on their lives. Unemployment, a longer duration of symptoms, and less education were associated with a higher average prevalence of all symptomatic themes (p < 0.01). Unemployment, a longer duration of symptoms, sex, and increased age were associated with a higher average effect of all symptomatic themes among patients with DM2 (p < 0.01). Conclusions: The lives of patients with DM2 are affected by a variety of symptoms. These symptoms have different levels of significance and prevalence in this population and vary across DM2 subgroups in different demographic categories.