NCT05662150

Low-frequency Repetitive Nerve Stimulation in Myotonic Dystrophy Type 1

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

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 9 (actual)
• Sponsor: Vrije Universiteit Brussel · Academic / Other
• Sex: All
• Age: —
• Healthy volunteers: Not accepted

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).

Conditions

• Myotonic Dystrophy 1

Interventions

Type	Name	Description
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.

Timeline

• Start date: 2021-09-01
• Primary completion: 2022-06-11
• Completion: 2022-06-20
• First posted: 2022-12-22
• Last updated: 2022-12-22

Locations

1 site across 1 country: Belgium