Low-frequency Repetitive Nerve Stimulation in Myotonic Dystrophy Type 1

December 21, 2022 updated by: Jella De Ville, Vrije Universiteit Brussel

Is Low-frequency Repetitive Nerve Stimulation a Reliable Test to Evaluate the Neuromuscular Junction in Myotonic Dystrophy Type 1

The study design is a prospective cohort study. It aims to evaluate the neuromuscular junction in dystrophic myotonia 1 (DM 1) using low-frequency repetitive nerve stimulation (RNS) on several nerve-muscle pairs of the one side including proximal and distal muscles of upper and lower extremities. First, it will be investigated whether a decrement with 3 Hz stimulation, as described in literature, is reproducible in our patient population. If this is the case, it will be examined whether it is the consequence of a dysfunction of the neuromuscular junction or rather linked to a hypo-excitability of some muscle fibers due to myotonia. For this purpose, additional tests including short exercise test (to observe any decrement resulting from an inexcitability in myotonic muscle fibers) and needle EMG (for mapping myotonic discharges in the muscles tested with repetitive nerve stimulation) will be performed. Single fiber-EMG will not be provided in this study as an abnormal result does not necessarily indicate a dysfunction of the neuromuscular junction but could just as well be due to the muscular dystrophy in the context of DM1. Finally, it will be investigated if there is a correlation between the decrement

with 3 Hz stimulation and clinical signs as fixed muscle weakness (via Medical Research Counsil (MRC) scale, DM-activ scale [30]) and fatigue (via MG-ADL scale).

Study Overview

Status

Completed

Study Type

Interventional

Enrollment (Actual)

9

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Brussels Hoofdstedelijk Gewest
      • Jette, Brussels Hoofdstedelijk Gewest, Belgium, 1000
        • UZ Brussel

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

* genetically confirmed DM1

Exclusion Criteria:

  • minor age
  • auto-immune diseases
  • medical conditions involving the neuromuscular junction: (myasthenia gravis, Lambert-Eaton myasthenic syndrome, congenital myasthenia syndromes).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Questionnaires
Patients with DM1 were asked to complete a questionnaire to rate a 25-item activity scale (DM1-Activ) and the Myasthenia Gravis Activity of Daily Life scale (MG-ADL) to rate their level of functional burden. For the DM1-Activ a score of 40 alludes no impairment and a score of 0 indicates the highest functional burden of physical activity. This scale has proven to be practical, reliable and valid. For the MG-ADL the total score ranges from 0 to 24, a score of 0 denotes no and 24 the highest functional burden. It should be noted that this scale is not adjusted for DM1. The rationale was to gain information about muscle fatigue and consequently the neuromuscular junction.
Neuromuscular transmission was tested by using short-lasting low frequency RNS (10 stimuli at 3 Hz). The test was applied on the abductor digiti minimi (ADM), anterior tibial, orbiculis oculi, trapezius, anconeus and EDB muscles of one side, in this particular order, by supramaximal stimulation of the corresponding nerve.
Active Comparator: grip strength via dynamometer
The isometric grip strength was tested by using a dynamometer. The subject will be asked to perform an increasing force against the dynamometer over a period of several seconds.
Neuromuscular transmission was tested by using short-lasting low frequency RNS (10 stimuli at 3 Hz). The test was applied on the abductor digiti minimi (ADM), anterior tibial, orbiculis oculi, trapezius, anconeus and EDB muscles of one side, in this particular order, by supramaximal stimulation of the corresponding nerve.
Active Comparator: short exercise test
The subject was asked to contract the ADM muscle as hard as possible in isometric conditions for 10 seconds. CMAP's was recorded 2 seconds after the end of the exercise and then every 10 seconds for 50 seconds.
Neuromuscular transmission was tested by using short-lasting low frequency RNS (10 stimuli at 3 Hz). The test was applied on the abductor digiti minimi (ADM), anterior tibial, orbiculis oculi, trapezius, anconeus and EDB muscles of one side, in this particular order, by supramaximal stimulation of the corresponding nerve.
Active Comparator: needle EMG
The electrical myotonia of each examined muscle was scored according to the Streiss and Sun scale.
Neuromuscular transmission was tested by using short-lasting low frequency RNS (10 stimuli at 3 Hz). The test was applied on the abductor digiti minimi (ADM), anterior tibial, orbiculis oculi, trapezius, anconeus and EDB muscles of one side, in this particular order, by supramaximal stimulation of the corresponding nerve.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Reproducibility of rapid decrement at low frequency stimulation.
Time Frame: 1 year
Low stimulation frequency was tested in 6 muscles, to verify the presence of an anomalie of the neuromuscular transmission.
1 year

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation of decrement with grade of EMG-myotonia
Time Frame: 1 year
Search of correlation between decrement, obtained bij low frequency stimulation, and EMG-myotonia (via needle EMG), to differentiate muscle fiber hypoexcitability in the context of myotonia, from neuromuscular junction block resulting in decrement of the CMA
1 year
Is there any clinical expression (muscle fatigability) of a possible neuromuscular junction dysfunction
Time Frame: 1 year
Search of correlation between muscle fatique (questionnaires and grip strength via dynamometer) and decrement of CMAP (compound muscle action potential).
1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Jella De Ville, MD, Universitair Ziekenhuis Brussel

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 1, 2021

Primary Completion (Actual)

June 11, 2022

Study Completion (Actual)

June 20, 2022

Study Registration Dates

First Submitted

October 14, 2022

First Submitted That Met QC Criteria

December 21, 2022

First Posted (Actual)

December 22, 2022

Study Record Updates

Last Update Posted (Actual)

December 22, 2022

Last Update Submitted That Met QC Criteria

December 21, 2022

Last Verified

December 1, 2022

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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