Nerve conduction studies (NCS), together with the needle electrode examination (NEE), constitute the electrodiagnostic examination. For most neuromuscular diagnostic problems, the NCS are the initial probe into the peripheral nervous system. The findings from the NCS will dictate what muscles must be studied during the subsequent NEE. Usually a complete electrodiagnostic impression depends upon the findings of both the NCS and the NEE, but only the NCS can confirm the presence of entrapment mononeuropathies, demyelinating neuropathies, and defects of neuromuscular junction (NMJ) transmission. Responses can be recorded along peripheral motor and sensory axons. Characteristics of the responses include the amplitude, duration, latency, and velocity of responses. From these parameters, patterns of nerve pathology can be identified, including axon loss, demyelination, and conduction block. Although there are no specific NCS features of myopathy, muscle fiber loss and muscle fiber inexcitability affect the amplitude of motor responses. With NMJ transmission defects, specific abnormalities on NCS are identified. <<< leia mais >>>