Neuroelectrogram refers to nerve conduction velocity and electromyography, which are neurophysiological examinations to determine whether a patient has muscle disease or peripheral nerve disease. The nerve conduction velocity test is used to check whether there is damage to the peripheral nerves. When there is damage to the nerves, there will be slowed nerve conduction velocity, decreased wave amplitude, and disappearance or delay of H-reflex. Electromyography is used to determine whether there is muscle damage and whether the cause of muscle damage is neuropathy or muscle disease. If the EMG indicates neurogenic damage, the muscle lesion is secondary to the nerve injury. If the EMG indicates myogenic damage, the primary disease of the muscle, such as polymyositis, myotonic dystrophy, and other metabolic myopathies, is considered.