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

During a nerve conduction test, an electrode is placed directly over the nerve to be studied. Another electrode is placed over the muscles supplied by that nerve. A brief electrical pulse is sent to the nerve. The time it takes for the muscle to contract in response to the pulse is measured.

Reasons for doing nerve conduction studies include:

• Finding damage to the peripheral nervous system. This system connects the brain and spinal cord to the other parts of the body.
• Finding the cause of abnormal sensations, such as numbness, tingling, or pain.