Nerve conduction studies are tests that measure how well individual nerves can send an electrical signal from the spinal cord to the muscles. Nerve conduction studies are often used to help diagnose nerve disorders, such as carpal tunnel syndrome or Guillain-Barré syndrome.

During a nerve conduction test, a health professional places a shock-emitting electrode directly over the nerve to be studied, and a recording electrode over the muscles supplied by that nerve. The shock-emitting electrode sends repeated, brief electrical pulses to the nerve, and the recording electrode records the time it takes for the muscle to contract in response to the electrical pulse.

Diagnostic uses for nerve conduction studies include:

• Detecting and evaluating damage to the peripheral nervous system, which includes all the nerves that lead away from the brain and spinal cord and the smaller nerves that branch out from those nerves.
• Identifying the cause of abnormal sensations, such as numbness, tingling, or pain.