Longitudinal Evaluation of Neuromuscular Involvement in Type 1 Myotonic Dystrophy

NCT07362316 | Completed

• 1 other identifier: NatHis DM1
• Study Type: observational
• Target: 50
• Locations: 2 countries
• Sites: 2

Brief Summary

Primary objective: To determine the sensitivity to change of neuromuscular functional outcomes during the natural (non-interventional) progression of myotonic dystrophy type 1 (DM1), in order to identify the most relevant and robust outcome measures for use in therapeutic trials. Secondary objective: To compare patients with DM1 to healthy control subjects to assess the discriminative power of biomechanical and electrophysiological parameters. Study design: This is an open-label, single-center observational study with no direct individual benefit. Participants: Thirty patients with DM1 will be evaluated three times over a three-year period, while thirty control subjects will be assessed once. Timeline: The planned inclusion period is 12 months, with a follow-up duration of 36 months, resulting in a total study duration of 48 months. Functional assessment-particularly muscle strength-is essential for both diagnosis and longitudinal monitoring of neuromuscular diseases. In therapeutic trials, outcome measures must meet strict scientific requirements, including precision, sensitivity, and reliability. Muscle strength is frequently used as a primary or secondary endpoint in trials targeting neuromuscular disorders. Even modest functional improvements resulting from therapy must be detectable with sensitive measurement tools. Myotonic dystrophy is the most common muscular dystrophy in adults, with an estimated prevalence of 1 in 8,000. It is a genetic disorder inherited in an autosomal dominant manner. Two genetically distinct forms are recognized: myotonic dystrophy type 1 (DM1, or Steinert disease) and the rarer, more recently identified type 2 (DM2). This study focuses on DM1 due to its higher prevalence and greater clinical severity. The study will assess parameters related to myotonia, muscle strength, motor function, and neuromuscular excitability. Patients will be evaluated every 18 months over a three-year period. Control subjects will undergo a single assessment. The expected outcome is the identification of the most robust and sensitive parameters for longitudinal monitoring of DM1 patients, particularly in the context of future therapeutic trials. A similar study will be conducted in parallel in Quebec (Principal Investigator: Prof. Jack Pumirat, CHU de Québec). Data common to both centers will be analyzed jointly.

Conditions

Steinert Myotonic Dystrophy

Keywords

Steinert Myotonic Dystrophy; DM1; Natural history

Outcome Measures

Primary Outcomes (1)

• Determine sensitivity to changes in neuromuscular functional criteria

  Determine sensitivity to changes in neuromuscular functional criteria during the natural progression (non-interventional follow-up) of patients with myotonic dystrophy type 1 in order to select the most relevant follow-up criteria during a therapeutic trial.

  18 and 36 months after baseline

Secondary Outcomes (1)

• Comparison of variables from patients with myotonic dystrophy type 1 and control subjects

  Baseline

Study Arms (2)

DM1 patients

Adults, no intervention

Other: Quantification of myotonia; Other: MyoAnkle; Other: Measurement of exercise-induced fatigue; Other: Moviplate; Other: 6-minute walk test; Other: Test du Box and Blocks; Other: Purdue board test; Other: 9-hole test; Other: Balance measurement

Healthy controls

Adults, no intervention

Other: Quantification of myotonia; Other: MyoAnkle; Other: Measurement of exercise-induced fatigue; Other: Moviplate; Other: 6-minute walk test; Other: Test du Box and Blocks; Other: Purdue board test; Other: 9-hole test; Other: Balance measurement

Interventions

MyoAnkle OTHER

Measurement of ankle flexion and extension strength

DM1 patients; Healthy controls

Quantification of myotonia OTHER

Measurement of relaxation time after exertion

DM1 patients; Healthy controls

Measurement of exercise-induced fatigue OTHER

Measurement of exercise-induced fatigue

DM1 patients; Healthy controls

Moviplate OTHER

Measurement of movement coordination and fatigue

DM1 patients; Healthy controls

6-minute walk test OTHER

The subject must walk between two cones separated by 25 m. During this test, a measurement of the quality of the walk will also be carried out using an accelerometer.

DM1 patients; Healthy controls

Test du Box and Blocks OTHER

Measures gross manual dexterity

DM1 patients; Healthy controls

Purdue board test OTHER

assessment of finger dexterity and gross hand, finger and arm movements

DM1 patients; Healthy controls

9-hole test OTHER

Evaluation of motor skills and coordination of the upper limbs

DM1 patients; Healthy controls

Balance measurement OTHER

Balance measurement on a force platform

DM1 patients; Healthy controls

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Patients will be recruited during neurological consultations at hospitals participating in the study. Healthy subjects will be recruited either from among the patients' friends and family members who are known not to carry the mutation, or through announcements made during consultations.

You may qualify if:

• For patients:
• Diagnosed with myotonic dystrophy type 1 confirmed by genetic analysis
• Presenting with motor weakness (MIRS score of 3 or 4)
• Able to walk for ten minutes
• Able to be informed and provide informed consent
• Affiliated with a French social security scheme
• For healthy subjects:
• Matched in age (± 1 year) and sex to patients
• Able to be informed and provide informed consent
• Affiliated with a French social security scheme

You may not qualify if:

• for patients and control subjects
• Participation in another ongoing biomedical research study
• Orthopaedic disorders of the ankle or hand
• Epilepsy
• Progressive cancer
• Insulin-dependent diabetes
• Unstabilised and uncontrolled hypertension under treatment (or treated with Propranolol, Prazosin or Clonidine) or blood pressure greater than 160/90 mmHg in the supine position
• Dementia syndrome, major depressive disorder
• History of drug or alcohol abuse in the last six months
• Vital capacity \< 50% or total lung capacity \< 50%, daytime mechanical ventilation (EFR less than 2 years old)
• Hypercapnia (PaCO2 ≥ 8 Kpa or 60 mmHg) (blood gas less than 2 years old)
• Visual disorders incompatible with the performance of the tests (e.g. cataracts, etc.)
• Women who are pregnant, breastfeeding or not using effective contraception
• Patients treated with cyclosporine
• Any condition that, in the investigator's opinion, would be incompatible with the proper conduct of the study.

Sponsors & Collaborators

• Institut de Myologie, France: lead

Study Sites (2)

Centre de recherche du CHU de Québec-Université Laval

Laval, Canada

Location

Institut de Myologie

Paris, Île-de-France Region, 75013, France

Location

MeSH Terms

Conditions

Myotonic Dystrophy

Interventions

Dental Occlusion

Condition Hierarchy (Ancestors)

Muscular Dystrophies; Muscular Disorders, Atrophic; Muscular Diseases; Musculoskeletal Diseases; Myotonic Disorders; Heredodegenerative Disorders, Nervous System; Neurodegenerative Diseases; Nervous System Diseases; Neuromuscular Diseases; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Intervention Hierarchy (Ancestors)

Dentistry; Dental Physiological Phenomena; Digestive System and Oral Physiological Phenomena

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: PROSPECTIVE
• Target Duration: 36 Months
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 14, 2026
• First Posted: January 23, 2026
• Study Start: September 23, 2010
• Primary Completion: December 15, 2015
• Study Completion: December 15, 2015
• Last Updated: January 23, 2026

Record last verified: 2026-01

Locations

CA (1); FR (1)