EMG measures the electrical activity of a muscle to the stimulation of the nerve and nerve conduction studies measure the speed of an electrical impulse through the nerve. Anaesthetics are given to prevent the patient from feeling sensations during a surgical or diagnostic procedure. It does this by slowing down or blocking signals that pass along the nerves to the brain. Thus, if any anaesthetics are given during EMG or nerve conduction studies, they would alter the activity of the nerves and muscles which would result in incorrect findings leading to an inaccurate diagnosis. Therefore, anaesthetics have no role in electromyography or nerve conduction studies.