RNS – A repetitive nerve stimulation (RNS) test is a type of nerve conduction study. It is a diagnostic procedure that checks how well your nerves and muscles communicate. It is basically used when unexplained muscle weakness and fatigue symptoms.

Indication – It commonly performs to diagnose neuromuscular junction disorders like Myasthenia gravis(MG), Lambton Eaten Myasthenic Syndrome (LEMS) or Myasthenic syndromes.

Preparation – Better to wear short-sleeved or loose-fitting garments so the technician can easily access your arms, shoulders, or neck, which are the area to be examined. If you take medications for muscle weakness (like Pyridostigmine), stop it before 24 hours after consulting your doctor.

How to perform – The technician will attach small electrodes on the skin. He gives you very brief, but delivers repeated/ a series of stimuli to the nerve. You will feel a twitching or small shock-like sensation. The Machine will record how the muscle responds with those stimuli. During the procedure, the doctor may ask you to exercise to examine the muscle for a few seconds to minutes and will see how the nerve-muscle responds with that.