Nerve Conduction Studies (NCS) is the testing of nerves in the body. In many ways the large nerves in the arms and legs are like electrical cables and they function by means of electrical impulses travelling along them.
The nerves in the limbs can be classified as motor or sensory. A motor nerve is one that runs down to a muscle and controls its movement. A sensory nerve is one that carries sensation to the nerve roots and spinal cord. Many individual nerves have both motor and sensory components, and NCS involves the testing of both motor and sensory nerves.
NCS is used mainly for evaluation of paraesthesia (numbness, tingling, burning) and weakness of the arms and legs. The type of study required is dependent in part by the symptoms presented. A physical exam and thorough history also help to direct the investigation. Some of the common disorders which can be diagnosed by NCS are:
• Peripheral neuropathy
• Carpal tunnel syndrome
• Ulnar neuropathy
• Guillain-Barré syndrome
• Facioscapulohumeral muscular dystrophy
• Spinal disc herniation
• Nerve damage
• Peripheral neuropathies
Although most nerve conduction studies are done on nerves in the arms and legs, it is quite possible to test nerves in other parts of the body.