Neurophysiological tests assess the function of the brain and nervous system. They measure normal and abnormal electrical impulses in the brain (Electroencephalogram or EEG) or electrical signals through nerves and their response in muscles. In patients with spinal conditions the most common tests are nerve conduction studies (NCS), electromyography (EMG) and spinal cord monitoring. The latter is performed during surgery.
Nerve Conduction Studies (NCS)
This test measures how fast a nerve impulse travels from one point to another along the nerve. The test is a measure of the speed and effectiveness with which nerves in the arms and legs send messages to the muscles or from the skin to enable you to move and feel. If there is a blockage due to pressure on a nerve the test can say how severe the pressure and where the blockage is. It is commonly used in the arm to look for carpal tunnel syndrome or ulnar nerve syndrome. No needles are involved but some discomfort can be experienced when the nerve is stimulated. There is no risk of damaging the nerve from the stimulation.