NMBAs interrupt impulses or signals from the nerve to the muscle. External stimulation also does NOT lead to a muscle contraction in a paralyzed patient. Once the body metabolizes the NMBA the signal can travel again from the nerve to the muscle and provoke a muscle twitch. This recovery is gradual meaning that the initial twitches are weak and gradually get stronger. Also muscle fatigue faster with NMBA present (fade). This means that with similar, repetitive stimulation the twitch gets weaker. In anesthesia these attributes are examined to determine the degree of muscle relaxation and, or if at all, a dose of NMBA reversal can be given and what the appropriate dose should be.