Low-frequency Repetitive Nerve Stimulation in Myotonic Dystrophy Type 1

Myotonic Dystrophy 1 Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT05662150
• Other study ID #: Steinert study
• Status: Completed
• Phase: N/A
• Start date: September 1, 2021
• Est. completion date: June 20, 2022

Study information

• Verified date: December 2022
• Source: Vrije Universiteit Brussel
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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).

Recruitment information / eligibility

• Status: Completed
• Enrollment: 9
• Est. completion date: June 20, 2022
• Est. primary completion date: June 11, 2022
• Accepts healthy volunteers: No
• Gender: All
• Age group: N/A and older

Eligibility

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).

Related Conditions & MeSH terms

• Myotonic Dystrophy
• Myotonic Dystrophy 1

Intervention

Diagnostic Test:
• Low frequency repetitive stimulation
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.

Locations

Country	Name	City	State
Belgium	UZ Brussel	Jette	Brussels Hoofdstedelijk Gewest

Sponsors (1)

Lead Sponsor	Collaborator
Vrije Universiteit Brussel

Country where clinical trial is conducted

Belgium, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Reproducibility of rapid decrement at low frequency stimulation.	Low stimulation frequency was tested in 6 muscles, to verify the presence of an anomalie of the neuromuscular transmission.	1 year
Secondary	Correlation of decrement with grade of EMG-myotonia	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
Secondary	Is there any clinical expression (muscle fatigability) of a possible neuromuscular junction dysfunction	Search of correlation between muscle fatique (questionnaires and grip strength via dynamometer) and decrement of CMAP (compound muscle action potential).	1 year