Using MRI in Patients With Non-dystrophic Myotonia to Access Muscle Contractility

• Conditions: Nondystrophic Myotonia; Paramyotonia Congenita

• Registration Number: NCT04808388
• Lead Sponsor: Rigshospitalet, Denmark

Brief Summary

The aim of this project is (1) to investigate whether or not structural muscle abnormalities could be a consequence of the disorder and (2) to provide further clinical description of this rare phenotype. To do so, the investigators will (1) use Dixon MRI to quantify fatty infiltration in muscle tissue and compare it to muscle strength measurements from isometric dynamometry in order to access contractility and (2) describe the myotonic phenotype with simple squeeze test and questionnaires.

Detailed Description

Non-dystrophic myotonias are rare genetic diseases in which the membrane excitability is altered by mutations in genes encoding muscle ion channels.

Patients suffer from myotonic stiffness, pain, fatigue and sometimes paralysis. Non-dystrophic myotonia is distinct from myotonic dystrophies with the absence of muscle degeneration.

Paramyotonica congenita is characterzied by paradoxial myotonia, which, in contrast to the more common myotonia congenita, is myotonic stiffness that worsens with activity. Typically, the first few contractions seem normal, whereas repetition leads to severe stiffness. Our hypophysis is that these patient might also suffer from muscle degeneration.

Study Timeline

• Study Start: 2021-02-02
• Study First Submitted: 2021-03-15
• Study First Submitted QC: 2021-03-18
• Study First Posted: 2021-03-22
• Status Verified: 2021-09
• Last Update Submitted: 2021-09-14
• Last Update Posted: 2021-09-16
• Primary Completion: 2021-12-30
• Study Completion: 2021-12-31

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 25

Inclusion Criteria

• 18 years of age
• Diagnosed with non-dystrophic myotonia

Exclusion Criteria

• MRI contraindications

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Contractile properties	1 year	Contractility = strength (kg) divided with cross sectional area of the muscle (CCSA)

Secondary Outcome Measures

Name	Time	Method
Muscle strength	1 year	Peak torque (maximal contraction in kg) accessed from isometric dynamometry
Cross sectional area (CCSA)	1 year	By using MRI to visualize the muscle

Trial Locations

Locations (1)

Neuromuscular Center Rigshospitalet; 🇩🇰 Copenhagen, Denmark