By observing the change in the muscle electrical response (CMAP) after several stimulations, a physician can assess for the presence of a neuromuscular junction disease, and differentiate between presynaptic and postsynaptic conditions.
[2] Repetitive nerve stimulation is used to diagnose neuromuscular junction (NMJ) disorders, the most common of which is myasthenia gravis.
It is best to advise patients to refrain from taking acetylcholinesterase inhibitors (e.g., Pyridostigmine Mestinon) for 6–8 hours before the study, unless medically contraindicated.
These agents make more ACH available to bind at the ACHRs and may potentially diminished CMAP decrement, resulting in a normal study (false negative).
A peripheral nerve is electrically stimulated, and the amplitude of the CMAP is recorded at rest and after a short voluntary activation.