RNS is an electrodiagnostic test which is used to assess the neuromuscular junction (NMJ).
RNS is performed when you have muscular fatigue symptoms. It is commonly done to diagnose neuromuscular junction (NMJ) disorders such as Myasthenia Gravis (MG) or Lambert-Eaton Myasthenic Syndrome (LEMS).
The response from your nerves in reaction to a repeated series of electrical stimuli will be recorded using a recording electrode which is placed on the tested muscle. You may be asked to exercise the tested muscle, for a few seconds to minutes, in between the series of electrical stimulation. Several nerves and muscles may be tested depending on your symptoms, and according to your doctor’s request, thus the test may take at least 45 minutes to 1 hour to complete.
No special preparation is needed for this test. However, do wear loose- fitting clothing so that your hands, shoulders and neck are easily accessible for examination. Do not apply any cream, ointment or cosmetics on your arms and face, and avoid wearing unnecessary accessories such as bangles, bracelets, rings and necklaces.
This test is safe and tolerable. Slight discomfort in the form of a tingling sensation and muscle twitching may be experienced throughout the test, but these will resolve quickly after the test.