Progressive Decline in Daily and Social Activities: A 9-year Longitudinal Study of Participation in Myotonic Dystrophy Type 1

Gender disparities in myotonic dystrophy 1

Myotonic Dystrophy Type 1 (DM1) is a complex, inherited disorder characterized by significant clinical heterogeneity, affecting multiple organ systems with varying severity and age of onset. It is a multisystemic disorder with a wide range of clinical presentations that lead to symptoms and complications associated with various body systems. Predicting the overall phenotype and prognosis is challenging due to the lack of a single determining factor, complicating medical management and clinical trials. While extensive research has explored the genetic and molecular mechanisms of DM1, the influence of gender on disease manifestations, progression, and outcomes remains elusive. Emerging evidence suggests that male patients often experience greater morbidity and mortality with severe muscular, cardiac, central nervous system, and respiratory impairments, while females are more prone to ophthalmological, gastrointestinal, and endocrine complications. Potential gender-based differences in inheritance patterns also require further investigation. Despite these disparities, gender-specific considerations are largely absent in clinical management and research, limiting the development of targeted therapeutic strategies. This review provides a comprehensive analysis of gender-related differences in DM1, emphasizing their implications for disease prognosis, diagnosis, and treatment. Recognizing gender as a crucial factor in DM1 research and clinical practice could improve patient outcomes and more personalized therapeutic approaches.

Living with adult-onset myotonic dystrophy type 1: a scoping review

PURPOSE

To identify the existing literature on experiences of living with adult-onset myotonic dystrophy type 1 (DM1) from people with adult-onset DM1, their caregivers and health care professionals.

MATERIALS AND METHODS

Following the framework of Arksey and O'Malley, a literature search was performed in five databases in October-November 2022. An updated search was conducted in December 2023. Studies were eligible if they reported on experiences related to living with DM1 from people with adult-onset DM1, caregivers or healthcare professionals. Qualitative, quantitative, and mixed method studies were included. Key findings were categorized using the International Classification of Functioning, Disability and Health (ICF) components.

RESULTS

11 out of 1842 studies were included, of which five had a quantitative design, five had a qualitative design and one study had a mixed methods design. The studies reported on multiple experiences of living with adult-onset DM1 from the perspectives of people with the disease and their caregivers. All components of the ICF were reported in the studies; activity and participation and personal factors were the most reported.

CONCLUSION

Adult-onset DM1 is a complex disease with great biopsychosocial impact making it challenging to live with for those diagnosed with DM1 as well as their caregivers.

New Horizons in Myotonic Dystrophy Type 1: Cellular Senescence as a Therapeutic Target

Myotonic dystrophy type 1 (DM1) is considered a progeroid disease (i.e., causing premature aging). This hypervariable disease affects multiple systems, such as the musculoskeletal, central nervous, gastrointestinal, and others. Despite advances in understanding the underlying pathogenic mechanism of DM1, numerous gaps persist in our understanding, hindering elucidation of the heterogeneity and severity of its symptoms. Accumulating evidence indicates that the toxic intracellular RNA accumulation associated with DM1 triggers cellular senescence. These cells are in a state of irreversible cell cycle arrest and secrete a cocktail of cytokines, referred to as a senescence-associated secretory phenotype (SASP), that can have harmful effects on neighboring cells and more broadly. We hypothesize that cellular senescence contributes to the pathophysiology of DM1, and clearance of senescent cells is a promising therapeutic approach for DM1. We will discuss the therapeutic potential of different senotherapeutic drugs, especially senolytics that eliminate senescent cells, and senomorphics that reduce SASP expression.

Effect of exercise training on clinical and physiological variables in adults with myotonic dystrophy type 1: A systematic review protocol

Myotonic dystrophy Type 1 (DM1) is a neuromuscular disease characterized by multisystemic involvement including a progressive loss of muscle mass and strength. Further investigation on the effect of exercise in adults with DM1 is needed to incorporate impactful recent findings to better understand the utility of exercise as an intervention. This review aims to summarize and appraise the literature on the effects of aerobic and strength training on clinical and physiological variables in adults with DM1. Six online databases (PubMed, Scopus, Web of Science, CINAHL, EMBASE, and CENTRAL) will be searched using appropriate search terms. Two reviewers will independently screen the relevant studies and extract the data from the selected articles. The methodological quality of the studies included will be assessed using the Joanna Briggs Critical Appraisal checklist. A meta-analysis will be performed if appropriate. This systematic review and meta-analysis will summarize, synthesize, and appraise evidence on the effect of aerobic and strength training on clinical and physiological variables in adults with DM1. The findings of this review will help in clinical decision-making and guide future researchers working with this patient population.

Latent factors underlying the symptoms of adult-onset myotonic dystrophy type 1 during the clinical course

BACKGROUND

Myotonic dystrophy type 1 (DM1) is a multisystem genetic disorder that classically presents with symptoms associated with myotonia, early onset cataracts, and muscular weakness, although the presentation and pattern of disease progression is quite varied. Presenting symptoms are well documented among adults with DM1. However, less is known about the co-occurrence of symptoms over time. We aimed to use factor analysis to explore the correlation pattern of signs and symptoms (S/S) that emerged during the clinical course.

RESULTS

Clinical records of 228 individuals with adult onset DM1 were abstracted using the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet) from a six-site cohort in the United States during an eight-year study period. Factor analysis was used to group the correlated S/S into latent factors. Three factors were identified. Group 1: 'Facial Weakness/Myotonia' includes the two most common S/S, as indicated by its name. Group 2: 'Skeletal Muscle Weakness' includes eight muscular S/S and is more frequently reported by males and those with older age at onset. Group 3: 'Gastrointestinal distress/Sleepiness' includes four non-muscular S/S and hand stiffness. The abstracted medical records reported that over 63% of individuals had S/S from all three groups. Associations of covariates with factor scores were also examined using linear regression. CTG repeat length was significantly positively associated with higher factor scores for all three factors.

CONCLUSIONS

This study identified three latent factors of S/S which accumulated during the clinical course of adult onset DM1.

Comprehensive four-year disease progression assessment of myotonic dystrophy type 1

Myotonic dystrophy type 1 (DM1) is a heterogeneous neuromuscular disorder characterized by progressive muscle weakness and myotonia. This study investigates the progression of muscular strength and function over a four-year period. Patients with DM1 were examined at baseline and four years later. The following metrics were assessed over time: muscle strength (Medical Research Council-sumscore), hand-grip strength (Martin-Vigorimeter), hand-grip relaxation time (myotonia), and limitations in activities of daily living and (DM1ActivC questionnaire). A total of 648 patients entered the registry. Recruitment and follow-up is ongoing. In our manuscript, we focus on, 187 patients who were followed for 4 years. A significant decline in MRC sum score was observed, with distal muscles showing more deterioration. Hand-grip strength decreased significantly, with notable differences between sex and phenotype classified by disease onset. Surprisingly, an improvement of myotonia was observed. Follow-up analysis revealed a significant interaction between myotonia and grip-strength over time. Thus, the improvement in myotonia is likely explained by decreased in grip strength. Finally, there was a significant reduction in DM1ActivC score, indicating decreased activity and social participation. This study demonstrated variability in disease progression depending on sex, phenotype and disease status. This research demonstrates a nuanced pattern of disease progression, highlighting the need to combine different outcome measures to fully understand the complexity of DM1.

Common Characteristics Between Frailty and Myotonic Dystrophy Type 1: A Narrative Review

Myotonic dystrophy type 1 (DM1) is an inherited neuromuscular disorder often considered a model of accelerated aging due to the early appearance of certain age-related clinical manifestations and cellular and molecular aging markers. Frailty, a state of vulnerability related to aging, has been recently studied in neurological conditions but has received considerably less attention in neuromuscular disorders. This narrative review aims to describe 1) the common characteristics between Fried's frailty phenotype criteria (muscular weakness, slow gait speed, weight loss, exhaustion/fatigue, and low physical activity) and DM1, and 2) the psychological and social factors potentially contributing to frailty in DM1. This review gathered evidence suggesting that DM1 patients meet four of the five frailty phenotype criteria. Additionally, longitudinal studies report the deterioration of these criteria over time in DM1. Patients also exhibit psychological/cognitive and social factors that might contribute to frailty. Monitoring frailty criteria in the DM1 population could help to implement timely preventions and interventions to reduce the disease burden and severity of frailty symptoms.

Evolution of Sleep Complaints in Myotonic Dystrophy Type 1: A 9-Year Longitudinal Study

The objective was to characterize the progression of sleep complaints in 115 dystrophy type 1 (DM1) patients who filled out a sleep questionnaire twice at a 9-year interval. Daytime napping (22.1% vs. 34.5%, p < 0.05), early awakenings (11.4% vs 21.1%, p < 0.05), nonrestorative sleep (39.5% vs 51.8%, p < 0.05), stimulant use (7.0% vs 19.3%, p < 0.01), breathing cessation (10.7% vs 23.2%, p < 0.01), and nighttime urination (42.5% vs 54.9%, p < 0.05) increased between Time 1 and Time 2. Sleep-related complaints are prominent and augment rapidly in DM1 patients. Physicians need to better identify and treat them to help alleviate the burden they impose on patients and their caregivers.

A retrospective study of needs and interventions among patients with myotonic dystrophy type 1 in Denmark referred to rehabilitation in the period 2000-2019

RATIONALE, AIMS AND OBJECTIVES: Myotonic dystrophy type 1 (DM1) is a progressive multisystem disorder that requires a special focus on the delivery of health and rehabilitation. The aim of the study was to identify the needs and interventions in patients with DM1 referred to a national rehabilitation hospital and to illustrate the needs and interventions in relation to predefined subgroups of disease classification.

METHOD

Electronic medical records from the period 2000-2019 of a randomized sample of patients with DM1 (N = 193) were reviewed to identify rehabilitation needs and interventions. The sample was classified into four subgroups of disease classifications. The number of identified needs and interventions were presented as medians and range, and differences between subgroups were illustrated by Kruskal-Wallis one-way analysis of variance. The needs were categorized using the International Classification of Functioning, Disability and Health (ICF).

RESULTS

A total of 2099 needs and 2103 interventions were registered. The most frequent needs were coordination of healthcare services (480) and employment and income (363), while the most frequent interventions were counselling (835) and follow-up (386). Patients with congenital DM1 had the most needs and interventions per person. In relation to the ICF, the most registered needs were environmental factors (880) and activity and participation (848).

CONCLUSION

All subgroups of patients with DM1 had a substantial number of needs and interventions related to coordinating and navigating within the healthcare system. The subgroup of patients with congenital DM1 had the most needs and interventions compared to the other subgroups.

Towards the Identification of Biomarkers for Muscle Function Improvement in Myotonic Dystrophy Type 1

BACKGROUND

Myotonic dystrophy type 1 (DM1) is the most common muscular dystrophy in adults. In DM1 patients, skeletal muscle is severely impaired, even atrophied and patients experience a progressive decrease in maximum strength. Strength training for these individuals can improve their muscle function and mass, however, the biological processes involved in these improvements remain unknown.

OBJECTIVE

This exploratory study aims at identifying the proteomic biomarkers and variables associated with the muscle proteome changes induced by training in DM1 individuals.

METHODS

An ion library was developed from liquid chromatography-tandem mass spectrometry proteomic analyses of Vastus Lateralis muscle biopsies collected in 11 individuals with DM1 pre-and post-training.

RESULTS

The proteomic analysis showed that the levels of 44 proteins were significantly modulated. A literature review (PubMed, UniProt, PANTHER, REACTOME) classified these proteins into biological sub-classes linked to training-induced response, including immunity, energy metabolism, apoptosis, insulin signaling, myogenesis and muscle contraction. Linear models identified key variables explaining the proteome modulation, including atrophy and hypertrophy factors. Finally, six proteins of interest involved in myogenesis, muscle contraction and insulin signaling were identified: calpain-3 (CAN3; Muscle development, positive regulation of satellite cell activation), 14-3-3 protein epsilon (1433E; Insulin/Insulin-like growth factor, PI3K/Akt signaling), myosin-binding protein H (MYBPH; Regulation of striated muscle contraction), four and a half LIM domains protein 3 (FHL3; Muscle organ development), filamin-C (FLNC; Muscle fiber development) and Cysteine and glycine-rich protein 3 (CSRP3).

CONCLUSION

These findings may lead to the identification for DM1 individuals of novel muscle biomarkers for clinical improvement induced by rehabilitation, which could eventually be used in combination with a targeted pharmaceutical approach to improving muscle function, but further studies are needed to confirm those results.

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.

Explanatory factors of dynamic balance impairment in myotonic dystrophy type 1

INTRODUCTION/AIMS

Myotonic dystrophy type 1 (DM1) is a neuromuscular disease affecting many systems and for which muscle weakness is one of the cardinal symptoms. People with DM1 also present with balance-related impairments and high fall risk. The aim of this study was to explore explanatory factors of dynamic balance impairment in the DM1 population.

METHODS

A secondary analysis of data collected as part of a larger study was performed. The Mini Balance Evaluation System Test (Mini-BESTest) was used to assess dynamic balance. Age, sex, and CTG repeat length in blood were retrieved from medical records and research files. The maximal isometric muscle strength of five lower limb muscle groups (hip flexors and extensors, knee flexors and extensors, and ankle dorsiflexors) was quantitatively assessed as well as fatigue. Standard multiple regression analysis was used.

RESULTS

Fifty-two individuals (31 men) aged between 24 and 81 years were included. The final model explains 65.9% of the balance score; ankle dorsiflexor muscle strength was the strongest explanatory factor, followed by CTG repeat length, age and fatigue to a lesser extent.

DISCUSSION

Dynamic balance is impaired in people with DM1. Results of this study suggest that rehabilitation interventions aimed at improving strength of the ankle dorsiflexors and managing fatigue could help to improve dynamic balance in this specific population.

Participation and Functional Independence in Adults With Recessive Spastic Ataxia of Charlevoix-Saguenay

Background. Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a progressive disorder where upper and lower extremities motor performances may bring participation restriction. Purpose. To document participation in adults with ARSAC and explore associations with motor performances. Method. Twenty-eight participants took part in the study. Participation was assessed using the LIFE-H. Motor performance was assessed using several outcomes including the SARA, LEMOCOT, Berg Balance Scale, 10-Meter Walk Test, and Finger-to-nose Test. Findings. Participation was significantly lower in the wheelchair user subgroup. Also, for 29 activities out of 77, at least 15% of participants reported severely disrupted participation. Participation was correlated with upper and lower limbs coordination, walking ability, balance, disease severity, and fine dexterity (Spearman r = .41–0.85, p < .03). Implications. Results showed significant participation restrictions and suggest that interventions aiming to improve or compensate upper and lower limbs functions could help to decrease disease burden.

Scoping study of definitions of social participation: update and co-construction of an interdisciplinary consensual definition

Background

considering the importance of social participation for quality of life and active ageing in older adults, it is an important target of social and health professionals’ interventions. A previous review of definitions of social participation in older adults included articles up to 2009; new publications and changes in the social context (e.g. social media and the COVID-19 pandemic) justify continuing this work.

Objective

this paper provides an updated inventory and synthesis of definitions of social participation in older adults. Based on a critical review by content experts and knowledge users, a consensual definition is proposed.

Methods

using a scoping study framework, four databases (MEDLINE, CINAHL, AgeLine, PsycInfo) were searched with relevant keywords. Fifty-four new definitions were identified. Using content analysis, definitions were deconstructed as a function of who, how, what, where, with whom, when, and why dimensions.

Results

social participation definitions mostly focused on people’s involvement in activities providing interactions with others in society or the community. According to this new synthesis and input from content experts and knowledge users, social participation can be defined as a person’s involvement in activities providing interactions with others in community life and in important shared spaces, evolving according to available time and resources, and based on the societal context and what individuals want and is meaningful to them.

Conclusion

a single definition may facilitate the study of active ageing and the contribution of older adults to society, socioeconomic and personal development, benefits for older adults and society, self-actualisation and goal attainment.

Assessment of muscular strength and functional capacity in the juvenile and adult myotonic dystrophy type 1 population: a 3-year follow-up study

INTRODUCTION

Myotonic dystrophy type 1 (DM1) is a progressive, multisystemic, and autosomal dominant disease. Muscle wasting and weakness have been associated with impaired functional capacity and restricted social participation in affected individuals. The disease's presentation is very heterogenous and its progression is still under-documented.

OBJECTIVE

The aim of the study was to document the progression of muscular strength and functional capacity in the DM1 population over a 3-year period.

METHODS

Twenty-three individuals with juvenile or adult phenotypes of DM1 were recruited to complete clinical assessments in 2016 and 2019. Maximal isometric muscle strength (MIMS) was evaluated with quantified muscle testing and functional capacity was evaluated with the Mini-BESTest, the 10-m walk test at comfortable and maximal speeds, the Timed Up and Go and the 6-min walk test. Participants also completed three questionnaires: DM1-Activ, Upper Extremity Functional Index and Lower Extremity Functional Scale (LEFS). Subgroup analyses were evaluated for sex, phenotype, and type of physical activity practiced during the 3-year period.

RESULTS

For the whole group, there was a significant decline in the scores of the Mini-BESTest and the LEFS. Also, MIMS significantly declined for prehension, lateral pinch as well as for hip abductors, knee extensors and ankle dorsiflexors muscle groups. Subgroups analyses revealed that men lost more MIMS than women, and that adult phenotype lost more MIMS than juvenile phenotype.

CONCLUSION

Quantified muscle testing is a better indicator of disease progression over a 3-year period than functional tests. Phenotype and sex are important factors that influence the progression of DM1.

Accomplishment of instrumental activities of daily living and its relationship with cognitive functions in adults with myotonic dystrophy type 1 childhood phenotype: an exploratory study

Background

The childhood phenotype of myotonic dystrophy type 1 (DM1) involves impaired cognitive functioning starting in infancy, which may compromise later on their ability to carry out instrumental activities of daily living (IADLs) necessary for living independently. The current study aims to document the ability to perform IADLs among adults with the childhood phenotype of DM1 and to explore its links to cognitive functioning.

Methods

This cross-sectional exploratory study was conducted among 11 individuals living with DM1. IADLs related to money management, home management & transportation and health & safety activities were assessed by the Independent Living Scale (ILS). Neuropsychological tests assessed participants’ intellectual abilities and executive functioning. Associations were investigated using Spearman’s rho correlation.

Results

Important difficulties were found in all three categories of IADLs, mostly in money management in which only 2/11 participants were scored as independent. 8/11 participants showed low to very low intellectual functioning and limit to impaired executive functioning. Apathy was also a common feature as 5/11 participants showed clinical level of apathy. A lower IQ was associated with greater difficulty in the home management & transportation subtest of the ILS.

Conclusions

Adults with the childhood phenotype of DM1 demonstrate relative dependence in regard to the following IADLs: money management and home management & transportation. Level of dependence is, at least partially, associated with cognitive impairments. The work relates to results from an exploratory study; thus, studies must be pursued to describe in more details difficulties experienced by this population.

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

Background: Muscle weakness is a cardinal sign of myotonic dystrophy type 1, causing important functional mobility limitations and increasing the risk of falling. As a non-pharmacological, accessible and safe treatment for this population, strength training is an intervention of choice. Objective: To document the effects and acceptability of an individualized semi-supervised home-based exercise program on functional mobility, balance and lower limb strength, and to determine if an assistive training device has a significant impact on outcomes. Methods: This study used a pre-post test design and men with the adult form of DM1 were randomly assigned to the control or device group. The training program was performed three times a week for 10 weeks and included three exercises (sit-to-stand, squat, and alternated lunges). Outcome measures included maximal isometric muscle strength, 10-Meter Walk Test, Mini-BESTest, 30-Second Chair Stand Test and 6-minute walk test. Results: No outcome measures showed a significant difference, except for the strength of the knee flexors muscle group between the two assessments. All participants improved beyond the standard error of measurement in at least two outcome measures. The program and the device were well accepted and all participants reported many perceived improvements at the end of the program. Conclusions: Our results provide encouraging data on the effects and acceptability of a home-based training program for men with the adult form of DM1. These programs would reduce the financial burden on the health system while improving the clinical services offered to this population.

DNA methylation at the DMPK gene locus is associated with cognitive functions in myotonic dystrophy type 1

Aim: Myotonic dystrophy type 1 (DM1) is caused by an unstable trinucleotide (CTG) expansion at the DMPK gene locus. Cognitive dysfunctions are often observed in the condition. We investigated the association between DMPK blood DNA methylation (DNAm) and cognitive functions in DM1, considering expansion length and variant repeats (VRs). Method: Data were obtained from 115 adult-onset DM1 patients. Molecular analyses consisted of pyrosequencing, small pool PCR and Southern blot hybridization. Cognitive functions were assessed by validated neuropsychological tests. Results: For patients without VRs (n = 103), blood DNAm at baseline independently contributed to predict cognitive functions 9 years later. Patients with VRs (n = 12) had different DNAm and cognitive profiles. Conclusion: DNAm allows to better understand DM1-related cognitive dysfunction etiology.

Predictors of participation restriction over a 9-year period in adults with myotonic dystrophy type 1

PURPOSE

For slowly progressive neuromuscular disease, prognostic approach and long-term monitoring of participation is a crucial part of rehabilitation services. To improve the prognostic approach, professionals must identify individuals at risk of having higher participation restriction. This study aimed to identify personal and environmental predictors of participation restriction over nine years in adults with myotonic dystrophy type 1 (DM1).

METHODS

A secondary analysis of a longitudinal design comparing baseline with a follow-up nine years later was used with a multidimensional assessment of participation and personal and environmental factors. Based on theoretical models, multiple linear regressions were used.

RESULTS

One hundred and fourteen adults with DM1 were included in the study (63.2% women; 78.9% adult onset; mean (SD) age of 43.5 (10.4) years). When age, sex, phenotype, and education were controlled for, participation restriction was predicted by a longer time to stand and walk, lower grip strength, higher body mass index, absence of perceived impact of myotonia in daily living, use of adapted transportation from community services, and perception of obstacle in physical environment (p < 0.001, adjusted R² = 0.50).

CONCLUSIONS

The majority of predictors of participation restriction can be advantageously modified by rehabilitation and environmental changes, such as politics targeting community services provision or physical environment and services accessibility.Implications for rehabilitationPredictors could better inform rehabilitation professional to recognize individuals at risk of higher participation restriction over time and to target specific interventions based on a prognostic approach.Rehabilitation professionals could inform the people living with myotonic dystrophy type 1 and their relatives of the multifactorial nature of occurrence of participation restriction to diminish the "fatality" associated with a genetic progressive disorder.Predictors allow professionals to assess and intervene in the management of specific factors depending on the rehabilitation goal.Identifying individual with myotonic dystrophy with higher risk of participation restriction could help implement a long-term community based rehabilitation intervention plan targeting both personal and environmental factors.

Validity of the Mini-BESTest in adults with myotonic dystrophy type 1

INTRODUCTION

Myotonic dystrophy type 1 (DM1) is a multisystemic neuromuscular disease that causes balance problems. The objective of this study was to assess the construct validity of the Mini-BESTest among adults with DM1.

METHODS

Fifty-nine individuals with late-onset or adult phenotypes of DM1 were recruited. Participants performed the Mini-BESTest, 10-Meter Walk Test (10mWT), 6-Minute Walk Test (6MWT), and Timed Up & Go (TUG) and were questioned on their tendency to lose balance and whether they fell in the past month.

RESULTS

Scores on the Mini-BESTest were significantly different between phenotypes and CTG repeat numbers (P < .02). Significant correlations were found with the 10mWT, 6MWT, and the TUG (r = 0.77-0.84; P < .001). A cutoff score of 21.5 was found to identify fallers with 90% posttest accuracy.

DISCUSSION

The Mini-BESTest demonstrates evidence of construct validity when assessing balance in the DM1 population.