Nerve conduction studies (NCS) or neurography evaluations are non-invasive electrodiagnostic techniques used commonly in neurology clinics for detection of nerve injury or degeneration along accessible portions of the peripheral nervous system.  Impaired function is evaluated by testing the ability of the nerve to conduct an electrical impulse (nerve conduction velocity). The technique involves recording electrical activity at a distance from the site where a propagating action potential is induced in a peripheral nerve. The nerve is stimulated at one or more sites along its course, and the electrical response of the nerve, or muscle innervated by the respective nerve, is recorded and analyzed.  Features of the compound muscle action potentials (CMAPs, for motor nerves) or sensory nerve action potentials (SNAPs, for sensory nerves) are used to assess demyelination, axonopathies and overall degeneration.  Late responses (F-waves and H-reflexes) can assess ascending pathways while repetitive nerve stimulation (RNS) is added where neuromuscular junction abnormalities are suspected.