What is the single fiber EMG?
The single-fiber EMG evaluates how well the nerve and muscle communicate. It involves insertion of a recording needle electrode into the area of the nerve-muscle communication point (the neuromuscular junction). There may be some discomfort with insertion of the electrodes (similar to an intramuscular injection, or a shot that goes right into the muscle). A single fiber EMG is often done on an eye, forehead, or forearm muscle. If a person is in remission, the SFEMG is normal, but if there is weakness from MG, the SFEMG is usually abnormal. Patients with ocular myasthenia will have an abnormal SFEMG. The diagnosis of MG is made after accounting for all the clinical symptoms and signs as well as the tests performed. Most patients tolerate the procedure well. A single-fiber EMG is a more technically difficult procedure than the standard EMG. Studies of this method suggest that it may detect abnormalities in over 95% of MG patients. However, other diseases may produce similar abnormalities
