Functioning and disability in adults with myotonic dystrophy type 1

The Role of Cognition, Affective Symptoms, and Apathy in Treatment Adherence with Noninvasive Home Mechanical Ventilation in Myotonic Dystrophy

Background

Chronic respiratory failure often occurs in myotonic dystrophy type 1 (DM1) and can be treated with noninvasive home mechanical ventilation (HMV). Treatment adherence with HMV is often suboptimal in patients with DM1, but the reasons for that are not well understood.

Objective

The aim of this exploratory study was to gain insight in the prevalence of mild cognitive impairment, affective symptoms, and apathy and to investigate their role in HMV treatment adherence in DM1.

Methods

The Montreal Cognitive Assessment (MoCA), the Hospital Anxiety and Depression Scale (HADS), and the Apathy Evaluation Scale (AES) were used to assess cognition, affective symptoms, and apathy in DM1 patients that use HMV. Patients with low treatment adherence (average daily use HMV <5 h or <80% of the days) were compared with patients with high treatment adherence (average daily use of HMV≥5 h and ≥80% of the days).

Results

Sixty patients were included. Abnormal scores were found in 40% of the total group for the MoCA, in 72-77% for the AES, and in 18% for HADS depression. There was no difference between the high treatment adherence group (n = 39) and the low treatment adherence group (n = 21) for the MoCA, AES, and HADS depression. The HADS anxiety was abnormal in 30% of the total group, and was significantly higher in the low treatment adherence group (p = 0.012). Logistic regression analysis revealed that a higher age and a higher BMI were associated with a greater chance of high treatment adherence.

Conclusions

This exploratory study showed that cognitive impairment and apathy are frequently present in DM1 patients that use HMV, but they are not associated with treatment adherence. Feelings of anxiety were associated with low treatment adherence. Higher age and higher BMI were associated with high treatment adherence with HMV.

Executive functions and daily functioning in myotonic dystrophy type 1 ecological assessment with virtual reality

Central nervous system dysfunction is characteristic of patients with myotonic dystrophy type 1 (DM1). Although no consensus exists regarding the exact cognitive profile of these patients, executive dysfunction has been suggested to play a role. Due to the impact of executive functions on daily performance, this study aimed to describe executive functioning in an ecological manner and to analyze its impact - and that of other clinical variables - on the functional performance of DM1 patients. A Virtual Reality executive functioning test (Nesplora Ice Cream), the Wechsler Adult Intelligence Scale-Fourth Edition, and self-report questionnaires (AES, FSS, ESS and LIFE-H) were administered to 20 patients. Statistical analyses included correlation and multiple regression analyses to analyze the best predictors of daily performance. DM1 patients did not show major difficulties in the executive functioning tasks or in their overall performance on daily habits. However, both cold and hot executive functions still seem necessary for the correct accomplishment of life habits, since planning and level of apathy explained 47.6% of the total variance of daily functioning. This was the first study to assess executive functions in DM1 using Virtual Reality, and our findings open a debate about their actual impairment in this population.

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.

Outcome measures frequently used to assess muscle strength in patients with myotonic dystrophy type 1: a systematic review

Measurement of muscle strength is fundamental for the management of patients with myotonic dystrophy type 1 (DM1). Nevertheless, guidance on this topic is somewhat limited due to heterogeneous outcome measures used. This systematic literature review aimed to summarize the most frequent outcome measures to assess muscle strength in patients with DM1. We searched on Pubmed, Web of Science and Embase databases. Observational studies using measures of muscle strength assessment in adult patients with DM1 were included. From a total of 80 included studies, 24 measured cardiac, 45 skeletal and 23 respiratory muscle strength. The most common method and outcome measures used to assess cardiac muscle strength were echocardiography and ejection fraction, for skeletal muscle strength were quantitative muscle test, manual muscle test and maximum isometric torque and medical research council and for respiratory muscle strength were manometry and maximal inspiratory and expiratory pressure. We successfully gathered the more consensual methods and measures to evaluate muscle strength in future clinical studies, particularly to test muscle strength response to treatments in patients with DM1. Future consensus on a set of measures to evaluate muscle strength (core outcome set), is important for these patients.

Clinical Outcome Evaluations and CBT Response Prediction in Myotonic Dystrophy

BACKGROUND

The European OPTIMISTIC clinical trial has demonstrated a significant, yet heterogenous effect of Cognitive Behavioural Therapy (CBT) for Myotonic Dystrophy type 1 (DM1) patients. One of its remaining aims was the assessment of efficacy and adequacy of clinical outcome measures, including the relatively novel primary trial outcome, the DM1-Activ-c questionnaire.

OBJECTIVES

Assessment of the relationship between the Rasch-built DM1-Activ-c questionnaire and 26 commonly used clinical outcome measurements. Identification of variables associated with CBT response in DM1 patients.

METHODS

Retrospective analysis of the to date largest clinical trial in DM1 (OPTIMISTIC), comprising of 255 genetically confirmed DM1 patients randomized to either standard care or CBT with optionally graded exercise therapy. Correlations of 27 different outcome measures were calculated at baseline (cross-sectional) and of their respective intervention induced changes (longitudinal). Bootstrap enhanced Elastic-Net (BeEN) regression was validated and implemented to select variables associated with CBT response.

RESULTS

In cross-sectional data, DM1-Activ-c correlated significantly with the majority of other outcome measures, including Six Minute Walk Test and Myotonic Dystrophy Health Index. Fewer and weaker significant longitudinal correlations were observed. Nine variables potentially associated with CBT response were identified, including measures of disease severity, executive cognitive functioning and perceived social support.

CONCLUSIONS

The DM1-Activ-c questionnaire appears to be a well suited cross-sectional instrument to assess a variety of clinically relevant dimensions in DM1. Yet, apathy and experienced social support measures were less well captured. CBT response was heterogenous, requiring careful selection of outcome measures for different disease aspects.

Factors Influencing the Severity and Progression of Respiratory Muscle Dysfunction in Myotonic Dystrophy Type 1

Respiratory complications are the most common cause of death among patients with Myotonic Dystrophy type 1 (DM1), but the natural history of respiratory decline in DM1 patients is incompletely characterized and few predictors of the progression of respiratory dysfunction have been identified. To identify factors influencing the progression of respiratory dysfunction electronic medical records from 110 adult patients diagnosed with DM1 were reviewed along with data for respiratory symptoms and pulmonary function obtained from routine respiratory therapist clinical evaluations. At baseline, 70.9% had evidence of restrictive respiratory impairment. We examined various parameters of respiratory functional status, and found FVC (% predicted) correlated best with other measures of disease severity. Annual change in FVC was −1.42 (std error = 0.381). Greater CTG repeat size, higher MIRS rating, and longer disease duration were all correlated with lower baseline FVC but not with annual rate of change. Wide variability in clinical phenotype made determination of disease measures directly related to respiratory functional decline challenging.

Pain in adult myotonic dystrophy type 1: relation to function and gender

Background

Pain is prevalent in myotonic dystrophy 1 (DM1). This study investigated whether CTG repeat size, disease duration, BMI and motor and psychological function were related to pain in adult patients with DM1, and if there were gender differences regarding intensity and location of pain.

Method

Cross-sectional design. Pain was investigated in 50 genetically confirmed DM1 patients by combining clinical assessment and self-reports of pain intensity and locations. Pain scoring results were related to CTG size, disease duration, muscle strength, walking capacity measured by 6-min walk test, activity of daily life by Katz ADL Index, respiratory function by Forced Vital Capacity and BMI. In addition, the degree of reported pain was related to Quality of life measured by WHOQOL-BREF; fatigue was measured by Fatigue severity scale; psychological functions were measured by Beck Depression Inventory, Beck Anxiety Inventory, IQ and Autism spectrum Quotient.

Results

Pain was reported in 84% of the patients and was significantly correlated with CTG size (r = 0.28 p = 0.050), disease duration (r = 0.38 p = 0.007), quality of life (r = − 0.37 p = 0.009), fatigue (r = 0.33 p = 0.02) and forced vital capacity (r = − 0.51, p = 0.005). Significant gender differences, with higher scores for females, were documented. In male subjects the number of pain locations was significantly correlated with quality of life and the autism quotient. In females, pain intensity was significantly correlated with activity, respiratory function and BMI.

Conclusions

Pain in DM1 was prevalent, with a strong association to lung function and other aspects of the disease. Significant gender differences were present for pain intensity and number of pain locations. How pain was related to other symptoms differed between male and female subjects. Our findings highlight the importance of assessments of pain in DM1 patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02124-9.

Effects of Teleassistance on the Quality of Life of People With Rare Neuromuscular Diseases According to Their Degree of Disability

Rare neuromuscular diseases (RNMDs) are a group of pathologies characterized by a progressive loss of muscular strength, atrophy, fatigue, and other muscle-related symptoms, which affect quality of life (QoL) levels. The low prevalence, high geographical dispersion and disability of these individuals involve difficulties in accessing health and social care services. Teleassistance is presented as a useful tool to perform psychosocial interventions in these situations. The main aim of this research is to assess the effects of a teleassistance psychosocial program on the QoL levels of people with RNMDs who have different levels of disability. A sample of 73 participants was divided into an experimental group (n = 40), which participated in the intervention, and a control wait list group (n = 33). QoL was evaluated through the SIP and the SF-36, and disability through the WHO-DAS II. The participants with a moderate to severe level of disability were those who most benefited from the intervention. The results also revealed that the psychosocial teleassistance program was suitable to improve physical and psychosocial aspects of people suffering from a rare neuromuscular disease with a moderate level of disability, but just psychosocial aspects in those with a severe level of disability.

Daily activity performance in congenital and childhood forms of myotonic dystrophy type 1: a population-based study

AIMS

To identify and describe the profile characterizing motor and process skills during daily activity performance in individuals with congenital and childhood forms of myotonic dystrophy type 1 (DM1) and to investigate differences in performance between subgroups.

METHOD

Sixty participants (34 males, 26 females, mean age=17y 8mo, SD=6y 0mo, range 5y 8mo-29y 0mo) were divided into severe congenital (n=9), mild congenital (n=20), and childhood (n=31) DM1 subgroups. Daily activity performance was evaluated using a standardized observational instrument: the Assessment of Motor and Process Skills.

RESULTS

Deficits in performance were more pronounced in process than motor skills. Performance more than 2 SDs below age-specific norms was seen in 65% of participants for process skills and 33% of participants for motor skills. The cut-off scores indicated a potential need for assistance in daily activities for 79% of participants older than 18 years of age (n=28) due to deficient process skills.

INTERPRETATION

Extensive deficits in daily activity performance were found in congenital and childhood forms of DM1, mainly owing to deficient process skills. Such skills impact on the ability to perform daily activities and could explain dependency in individuals with DM1. Process skills should be considered when evaluating daily activity performance.

WHAT THIS PAPER ADDS

Young people with myotonic dystrophy type 1 show deficits in motor and process skills when performing daily activities, compared with normative data. Deficits in process skills were more pronounced than deficits in motor skills.

Activities of daily living in myotonic dystrophy type 1

OBJECTIVES

The objective of this cross-sectional, observational study was to investigate performance of activities of daily living in patients with myotonic dystrophy type 1 (DM1).

MATERIALS AND METHODS

Adults with genetically confirmed DM1 were recruited from Newcastle University (Newcastle upon Tyne, UK) and University College London Hospitals NHS Foundation Trust (London, UK). Data on activities of daily living were recorded through the DM1-ActivC (scale scores range between 0 and 100, where a higher/lower score indicates a higher/lower ability).

RESULTS

Our sample comprised 192 patients with DM1 (mean age: 46 years; 51% female). Patients reported most difficulties with running, carrying and putting down heavy objects, and standing on one leg, and least difficulties with eating soup, washing upper body, and taking a shower. Irrespective of the disease duration (mean: 20 years), most patients were able to perform basic and instrumental activities of daily living (eg personal hygiene and grooming, showering, eating, cleaning and shopping), with the exception of functional mobility/transfer tasks (eg walking uphill and running). The mean DM1-ActivC total score was estimated at 71 (95% CI: 68-74). Estimated progenitor cytosine-thymine-guanine repeat length and age explained 27% of the variance in DM1-ActivC total scores (P < .001).

CONCLUSIONS

We show that DM1 impairs performance of activities of daily living, in particular those requiring a high degree of muscle strength, stability and coordination. Yet, across the evolution of the disease, the majority of patients will still be able to independently perform most basic and instrumental activities of daily living.

MRI of trunk muscles and motor and respiratory function in patients with myotonic dystrophy type 1

Background

Myotonic Dystrophy 1 (DM1) causes progressive myopathy of extremity muscles. DM1 may also affect muscles of the trunk. The aim of this study was to investigate fat infiltration and muscle size in trunk muscles in DM1 patients, and in an age and gender matched control group. Further, explore how fat infiltration and degree of atrophy in these muscles are associated with motor and respiratory function in DM1 patients.

Method

We measured fat infiltration and trunk muscle size by MRI in 20 patients with genetically confirmed classic form of DM1, and compared these cases with 20 healthy, age and gender matched controls. In the DM1 group, we investigated correlations between MRI findings and clinical measures of muscle strength, mobility and respiration. We used sum scores for fat infiltration and muscle size in trunk flexors and trunk extensors in the analysis of group differences and correlations.

Results

Significant differences between cases and controls were present for fat infiltration in trunk flexors (p = 0.001) and trunk extensors (p = < 0.001), and for muscle size in trunk flexors (p = 0.002) and trunk extensors (p = 0.030). Fat infiltration in trunk flexors were significant correlated to back extension strength (rho = − 0.523 p = 0.018), while muscle size in trunk flexors was significantly correlated to trunk flexion strength (rho = 0.506 p = 0.023). Fat infiltration in trunk flexors was significantly correlated with lower general mobility (rho = − 0.628, p = 0.003), reduced balance (rho = 0.630, p < 0.003) and forced vital capacity (rho − 0.487 p = 0.040).

Conclusions

Trunk muscles in DM1 patients had significant higher levels of fat infiltration and reduced muscle size compared to age and gender matched controls. In DM1 patients, fat infiltration was associated with reduced muscle strength, mobility, balance and lung function, while muscle size was associated with reduced muscle strength and lung function. These findings are of importance for clinical management of the disease and could be useful additional outcome measures in future intervention studies.

Electronic supplementary material

The online version of this article (10.1186/s12883-019-1357-8) contains supplementary material, which is available to authorized users.

Affective symptoms and apathy in myotonic dystrophy type 1 a systematic review and meta-analysis

BACKGROUND

To gain insight into the prevalence of apathy, depression and anxiety symptoms in myotonic dystrophy type 1 (DM1) patients on the basis of a systematic review with a meta-analysis.

METHODS

One author systematically searched and selected studies from Embase, Medline, PsychInfo and Web of Science (index periods up to August 2018). Data extraction and bias assessment were performed independently by two authors. We calculated (1) a weighted pooled prevalence and (2) weighted pooled standardized mean difference (Hedges' g) from studies comparing DM1 patients to healthy and/or neuromuscular disease controls separately for symptoms of depression, anxiety and apathy.

RESULTS

The pooled prevalences of depression (26 studies, n = 1267 DM1 patients), anxiety (19 studies, n = 896) and apathy (5 studies, n = 428), were 18% (95%CI: 12-25), 16 (95%CI: 13-18) and 55% (95%CI: 50-60), respectively. Effect sizes (Hedges' g) for depression, anxiety and apathy in DM1 patients compared to healthy controls were 1.04 (95%-CI: 0.71 to 1.37), 0.87 (95%-CI: 0.51 to 1.24) and 1.13 (95%-CI:0.54-1.71). Effect sizes for symptoms of depression, anxiety and apathy were 0.29 (95% CI: -0.12 to 0.70), 0.45 (95%-CI: -0.31 to 1.22) and 1.12 (95%-CI: 0.32-1.93) for DM1 patients versus neuromuscular disease controls. In most analyses, statistical heterogeneity was high.

CONCLUSIONS

Estimated pooled prevalences of clinically significant levels of symptoms of depression, anxiety and apathy in DM1 are 19, 17 and 55% respectively. Symptoms of depression and anxiety in DM1 may reflect reactive adjustment to progressive impairment and restricted participation similar to other chronic neuromuscular disease. The literature on the prevalence and severity of apathy, although a clinically relevant and characteristic symptom of DM1, is relatively scarce.

Respiratory dysfunction in myotonic dystrophy type 1: A systematic review

Myotonic dystrophy type 1 (DM1) is one of the most common muscular dystrophies in adults. This review summarises the current literature regarding the natural history of respiratory dysfunction in DM1, the role of central respiratory drive and peripheral respiratory muscle involvement and its significance in respiratory function, and investigates the relationship between genetics (CTG repeat length) and respiratory dysfunction. The review included all articles that reported spirometry on 10 or more myotonic dystrophy patients. The final review included 55 articles between 1964 and 2017. The major conclusions of this review were (1) confirmation of the current consensus that respiratory dysfunction, predominantly a restrictive ventilatory pattern, is common in myotonic dystrophy and is associated with alveolar hypoventilation, chronic hypercapnia, and sleep disturbance in the form of sleep apnoea and sleep related disordered breathing; (2) contrary to commonly held belief, there is no consensus in the literature regarding the relationship between CTG repeat length and severity of respiratory dysfunction and a relationship has not been established; (3) the natural history and time-course of respiratory functional decline is very poorly understood in the current literature; (4) there is a consensus that there is a significant involvement of central respiratory drive in this alveolar hypoventilation however the current literature does not identify the mechanism for this.

A Review of Psychopathology Features, Personality, and Coping in Myotonic Dystrophy Type 1

BACKGROUND

The last literature review on psychopathological features in Myotonic Dystrophy type 1 had been conducted by Ambrosini and Nurnberg in 1979. Since that date, many researches had been carried out.

OBJECTIVE

The aim of this study is (i) to systematically obtain and evaluate the relevant literature on psychopathological features, personality, and coping in individuals with adult phenotypes of Myotonic Dystrophy type 1. (ii) To summarize current research findings and draw conclusions for future research.

METHODS

A systematic search was conducted on Pubmed, PubPsych, PsycInfo, Science Direct, and Scopus covering the period of January 1979 to July 2017.

RESULTS

In view of our literature review, patients show mild psychopathological problems, such as interpersonal difficulties, lack of interest, dysphoria, concern about bodily functioning, and hypersensibility. However, they do not experience more psychiatric disorder in comparison to the general population, except for personality disorders and depression. We discussed problems concerning depression's assessment tool. Patients also present symptoms of several personality disorders: avoidant personality disorder was the most common. Finally, coping strategies relative to limitations resulting from their disease have a negative impact on their quality of life.

CONCLUSIONS

In conclusion, Myotonic Dystrophy type 1 patients did not present homogeneous psychopathological and psychological features. However, based on tendencies observed among Myotonic Dystrophy type 1 patients, elements to conceptualize their social difficulties are provided.

Validation of the Nine Hole Peg Test as a measure of dexterity in myotonic dystrophy type 1

We aimed to validate the Nine Hole Peg Test as a measure of dexterity in myotonic dystrophy type 1 (DM1). Fifty patients with adult-onset, genetically confirmed DM1 were evaluated by Nine Hole Peg Test and re-evaluated at one week. Myotonia was not a limiting factor. The first test was compared with that performed by normal subjects (n = 28). Contextually, patients underwent handgrip and three-finger pinch assessments by handheld dynamometer. The Nine Hole Peg Test showed high intra-rater and inter-rater reliability in DM1 [ICC 0.86/0.83 for dominant and 0.90/0.88 for non-dominant hand, respectively]. Inverse correlation with handgrip and pinch strength values (r = -0.4; p < 0.01) and direct correlation with Muscular Impairment Rating Scale (r = 0.4; p < 0.01) were found for both DH and NDH. The test was able to differentiate severe DM1 patients, stratified by extent of muscle impairment, from mildly affected and normal controls, with a sensitivity of 97% and 95% for dominant hand and non-dominant hand, respectively (p < 0.0001). In conclusion, we showed that the Nine Hole Peg Test is a reliable, valid and sensitive test of dexterity in DM1, and that it can be considered as a candidate outcome measure to monitor natural history of disease and, possibly, therapeutic response in clinical trials.

Cognitive behavioural therapy with optional graded exercise therapy in patients with severe fatigue with myotonic dystrophy type 1: a multicentre, single-blind, randomised trial

BACKGROUND

Myotonic dystrophy type 1 is the most common form of muscular dystrophy in adults and leads to severe fatigue, substantial physical functional impairment, and restricted social participation. In this study, we aimed to determine whether cognitive behavioural therapy optionally combined with graded exercise compared with standard care alone improved the health status of patients with myotonic dystrophy type 1.

METHODS

We did a multicentre, single-blind, randomised trial, at four neuromuscular referral centres with experience in treating patients with myotonic dystrophy type 1 located in Paris (France), Munich (Germany), Nijmegen (Netherlands), and Newcastle (UK). Eligible participants were patients aged 18 years and older with a confirmed genetic diagnosis of myotonic dystrophy type 1, who were severely fatigued (ie, a score of ≥35 on the checklist-individual strength, subscale fatigue). We randomly assigned participants (1:1) to either cognitive behavioural therapy plus standard care and optional graded exercise or standard care alone. Randomisation was done via a central web-based system, stratified by study site. Cognitive behavioural therapy focused on addressing reduced patient initiative, increasing physical activity, optimising social interaction, regulating sleep-wake patterns, coping with pain, and addressing beliefs about fatigue and myotonic dystrophy type 1. Cognitive behavioural therapy was delivered over a 10-month period in 10-14 sessions. A graded exercise module could be added to cognitive behavioural therapy in Nijmegen and Newcastle. The primary outcome was the 10-month change from baseline in scores on the DM1-Activ-c scale, a measure of capacity for activity and social participation (score range 0-100). Statistical analysis of the primary outcome included all participants for whom data were available, using mixed-effects linear regression models with baseline scores as a covariate. Safety data were presented as descriptives. This trial is registered with ClinicalTrials.gov, number NCT02118779.

FINDINGS

Between April 2, 2014, and May 29, 2015, we randomly assigned 255 patients to treatment: 128 to cognitive behavioural therapy plus standard care and 127 to standard care alone. 33 (26%) of 128 assigned to cognitive behavioural therapy also received the graded exercise module. Follow-up continued until Oct 17, 2016. The DM1-Activ-c score increased from a mean (SD) of 61·22 (17·35) points at baseline to 63·92 (17·41) at month 10 in the cognitive behavioural therapy group (adjusted mean difference 1·53, 95% CI -0·14 to 3·20), and decreased from 63·00 (17·35) to 60·79 (18·49) in the standard care group (-2·02, -4·02 to -0·01), with a mean difference between groups of 3·27 points (95% CI 0·93 to 5·62, p=0·007). 244 adverse events occurred in 65 (51%) patients in the cognitive behavioural therapy group and 155 in 63 (50%) patients in the standard care alone group, the most common of which were falls (155 events in 40 [31%] patients in the cognitive behavioural therapy group and 71 in 33 [26%] patients in the standard care alone group). 24 serious adverse events were recorded in 19 (15%) patients in the cognitive behavioural therapy group and 23 in 15 (12%) patients in the standard care alone group, the most common of which were gastrointestinal and cardiac.

INTERPRETATION

Cognitive behavioural therapy increased the capacity for activity and social participation in patients with myotonic dystrophy type 1 at 10 months. With no curative treatment and few symptomatic treatments, cognitive behavioural therapy could be considered for use in severely fatigued patients with myotonic dystrophy type 1.

FUNDING

The European Union Seventh Framework Programme.

A 9-year follow-up study of the natural progression of upper limb performance in myotonic dystrophy type 1: A similar decline for phenotypes but not for gender

This study aimed to document and compare the decline of upper limb performance among adults with myotonic dystrophy type 1 according to phenotype and gender. A longitudinal descriptive design compared upper limb performance at baseline and follow-up of 70 women and 38 men with the late-onset or adult phenotypes. Grip strength and pinch strength as well as gross dexterity and fine dexterity were assessed. All four performance measures decreased significantly (p <0.001). The decline over time was similar for individuals with the late-onset and adult-onset phenotypes, but differed according to gender. For late-onset and adult-onset phenotypes respectively, women lost less grip strength than men: 0.4 and minus 0.8 kg (2.0% and -9.4%) in women vs. minus 7.4 and minus 3.1 kg (-19.2% and -30.7%) in men. A similar situation was found for gross dexterity: minus 3.0 and minus 3.2 blocks (-4.6% and -5.9%) in women vs. minus 12.4 and minus 8.7 blocks (-19.4% and -16.6%) in men. Pinch gauge had the smallest standard deviations and was one of the only measurement tools with significant detectable changes in relation to the standard error of measurement. Given these results, health professionals and researchers should consider phenotype and gender differently when planning health services or future studies. Indeed, as their upper limb strength and dexterity differed, even if their decline was similar, the phenotypes should not be pooled. Finally, the use of the pinch gauge to assess long-term change in upper limb ability seems preferable to the three other measurements.

Primary cataract as a key to recognition of myotonic dystrophy type 1

PURPOSE

Primary cataract is often the initial manifestation of the adult-onset type of myotonic dystrophy type 1 (DM1), the most common muscular dystrophy in adults. It is caused by a CTG repeat expansion within the DMPK gene, and anticipation may cause earlier onset and more severe symptoms in subsequent generations.

METHODS

We report a family with hereditary cataract, which was initially classified as primary hereditary cataract. After presentation of 2 children with motor development delay and behavioral changes, DM1 was diagnosed. Subsequently, various DM1 features were recognized in older family members.

CONCLUSIONS

This report aims to increase awareness among ophthalmologists of the high prevalence of DM1 among young primary cataract patients. Ophthalmologists can play a significant role in early diagnosis, since cataract frequently is the first occasion that patients seek medical attention. Early recognition is crucial since it enables adequate cardiac follow-up and allows counseling of couples of childbearing age.

Lower limb muscle impairment in myotonic dystrophy type 1: the need for better guidelines

In myotonic dystrophy type 1 (DM1), leg muscle weakness is a major impairment. There are challenges to obtaining a clear portrait of muscle strength impairment. A systematic literature review was conducted on lower limb strength impairment in late-onset and adult phenotypes to document variables which affect strength measurement. Thirty-two articles were reviewed using the COSMIN guidelines. Only a third of the studies described a reproducible protocol. Only 2 muscle groups have documented reliability for quantitative muscle testing and only 1 total score for manual muscle testing. Variables affecting muscle strength impairment are not described in most studies. This review illustrates the variability in muscle strength assessment in relation to DM1 characteristics and the questionable validity of the results with regard to undocumented methodological properties. There is therefore a clear need to adopt a consensus on the use of a standardized muscle strength assessment protocol.

Impact of habitual exercise on the strength of individuals with myotonic dystrophy type 1

OBJECTIVE

It remains unclear whether habitual physical activity can attenuate the rate of progressive muscle strength loss in individuals with myotonic dystrophy type 1 (DM1). The aim of this study was to identify whether there were any strength differences between DM1 patients who were habitually active or sedentary.

DESIGN

Knee extension, handgrip, and elbow flexion quantitative strength measurements were investigated in the DM1 patients using isokinetic dynamometry. Strength was compared between the patients who followed self-selected formal exercise plans for at least 1 yr, those who were sedentary (controls), and those who initiated or terminated a formal exercise routine.

RESULTS

Physically active DM1 patients with midrange CTG repeat size (100-500 CTG repeat sizes) had significantly stronger handgrip and knee extension and elbow flexion torques as compared with their sedentary counterparts with the same CTG repeat range. The DM1 patients who began a formal exercise routine experienced a significant improvement in knee extension torque measurements (+24.3%) in comparison with those who were habitually active or sedentary.

CONCLUSIONS

These data suggest that there is an association between physical activity and strength. This may be shown to be a useful tool for the management of this condition. Further investigations into the relationships between physical exercise, muscle weakness, and genetic factors are needed before evidence-based recommendations can be made.

Effectiveness of Teleassistance at Improving Quality of Life in People with Neuromuscular Diseases

Rare neuromuscular diseases (NDs) are a group of inherited or acquired neurological pathologies affecting the muscles and the nervous system. Their low prevalence and high geographical dispersion can cause isolation and difficulties in social interaction between affected equals. New technologies, such as videoconferencing, offer a complementary option for improving the health of this population. The purpose of this study was to assess the effectiveness of a teleassistance program at improving health-related quality of life (HRQoL) through social interaction in adults with NDs. The sample consisted of 45 participants affected by rare NDs. Twenty-four participants were assigned to the experimental group (EG), which participated in the videoconferencing sessions, and 21 to the control group. Three questionnaires were administered: WHO-DAS II, Sickness Impact Profile, and SF-36 Health Survey. Effectiveness was assessed by a pre-post design. An online psychosocial program was applied over three-month period. Data revealed an improvement of the EG in psychosocial variables, e.g. “Getting along with people” (z = –2.289, r = –.47, p ≤ .05) or “Psychosocial Domain” (z = –2.404, r = –.49, p ≤ .05), and in physical variables, e.g. “Life activities” (z = –2.844, r = –.58, p ≤ .05). Social interaction appeared as a relevant factor at improving HRQoL levels. High levels of satisfaction about the teleassistance program were reported.

Effects of hand-training in persons with myotonic dystrophy type 1--a randomised controlled cross-over pilot study

PURPOSE

To investigate the effects of a hand-training programme on grip, pinch and wrist force, manual dexterity and activities of daily living, in adults with myotonic dystrophy type 1 (DM1).

METHOD

In this randomised controlled trial with a crossover design, 35 adults with DM1 were, after stratification for grip force, assigned by lot to two groups. Group A started with 12 weeks of hand training, while group B had no intervention. After a wash-out period of 12 weeks, where none received training, the order was reversed. The Grippit® was used as primary outcome measure and the hand-held Microfet2™ myometer, the Purdue Pegboard, the Canadian Occupational Performance Measure (COPM) and the Assessment of Motor and Process Skills (AMPS) were secondary outcome measures. Assessments were performed before and after training and control periods, i.e. four times altogether.

RESULTS

Ten persons dropped out and 13 had acceptable adherence. Intention-to-treat analyses revealed significant intervention effects for isometric wrist flexor force (p = 0.048), and for COPM performance (p = 0.047) and satisfaction (p = 0.027). On an individual level, improvements were in general showed after a training period.

CONCLUSION

The hand-training programme had positive effects on wrist flexor force and self-perception of occupational performance, and of satisfaction with performance. No evident detrimental effects were shown.

IMPLICATIONS FOR REHABILITATION

Myotonic dystrophy type 1 (DM1) is a slowly progressive neuromuscular disease characterised by myotonia and muscle weakness and wasting. People with DM1 are often concerned about their ability to carry out ADL and to participate in, e.g. work, sports and hobbies when they gradually become weaker. This pilot study showed that a hand-training programme improved wrist flexor force and self-perception and satisfaction of occupational performance. Resistance training of hand muscles with a silicon-based putty can be a therapy option for people with DM1 in clinical practise.

The relationship between walking, manual dexterity, cognition and activity/participation in persons with multiple sclerosis

Background: Multiple sclerosis has a vast impact on health, but the relationship between walking, manual dexterity, cognition and activity/participation is unclear.

Objective: The specific aims were to explore the discriminative ability of measures of walking, manual dexterity and cognition, and to identify cut-off values in these measures, for prediction of independence in personal and instrumental activities of daily living (ADL) and activity/participation in social and lifestyle activities.

Methods: Data from 164 persons with multiple sclerosis were collected during home visits with the following measures: the 2 × 5 m walk test, the Nine-hole Peg Test, the Symbol Digit Modalities Test, the Katz Personal and Instrumental ADL Indexes, and the Frenchay Activities Index (measuring frequency in social and lifestyle activities).

Results: The 2 × 5 m walk test and the Nine-hole Peg Test had high and better discriminative and predictive ability than the Symbol Digit Modalities Test. Cut-off values were identified. The accuracy of predictions was increased above all by combining the 2 × 5 m walk test and the Nine-hole Peg Test.

Conclusion: The proposed cut-off values in the 2 × 5 m walk test and the Nine-hole Peg Test may be used as indicators of functioning and to identify persons risking activity limitations and participation restrictions. However, further studies are needed to confirm the usefulness in clinical practice.