Muscle relaxation time as outcome measure in patients with non-dystrophic and dystrophic myotonic syndromes; voluntary handgrip- versus peripheral nerve stimulation myometry

Conditions: inherited muscle stiffness
Myotonia
10028302

Registration Number: NL-OMON35579

Lead Sponsor: niversitair Medisch Centrum Sint Radboud

Brief Summary: Not available

Detailed Description: Not available

Recruitment & Eligibility

Status: Pending

Sex: Not specified

Target Recruitment: 0

Inclusion Criteria

Patients with a genetically confirmed mutation in the gene encoding for the skeletal muscle sodium channel (SCN4A) or chloride channel (CLCN1) or a genetically determined mutation in the DMPK-gene, with clinical presence of hand (action) myotonia and between 18 and 65 years of age. Groups will be age and sex matched.

Exclusion Criteria

Comorbidity in form of a neurological or metabolic disorder that can interfere with normal muscle function. Usage of medication that can influence myotonia or muscle force (such as sodium channel blockers as widespreas used for cardiological and neurological diseases, that might also influence skeletal muscle channels). Cardial or Nephrological comoborbidity that do not allow a potassium low diet. Pregnant women. Unwillingness or unable to sign informed consent forms or to place the hand or lower arm in de myometry test set-up.

Study & Design

Study Type: Observational non invasive

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>Outcome measures are the mean muscle-RT and intraclass-correlation-coefficient<br /><br>(ICC). Differences in mean muscle-RT between the group of healthy volunteers<br /><br>and each of the patientgroups will be a measure for the reliability and<br /><br>robustness of the muscle-RT as outcome measure for myotonia. This reliability<br /><br>will be calculated for both methods within the different patientgroups. To<br /><br>determine the reproducability of these measurements within both methods, the<br /><br>ICC will also be calculated. </p><br>

Secondary Outcome Measures