Nerve conduction studies (NCS) and electromyography (EMG) are diagnostic tests that are used to evaluate the function of the nerves and muscles. NCS measures the speed and strength of nerve impulses as they travel through a nerve. EMG measures the electrical activity of a muscle at rest and during contraction.
NCS and EMG are often used to diagnose conditions that affect the nerves and muscles, such as nerve damage, muscle disorders, and neuropathies. They can also be used to monitor the effectiveness of treatment for these conditions.
NCS is typically performed by a specialist such as a neurologist or neurophysiologist. During the test, small electrodes are placed on the skin over the nerve being tested. A small shock is then delivered to the nerve, and the electrodes measure the response of the nerve as the impulse travels down the nerve.
EMG is also typically performed by a specialist such as a neurologist or neurophysiologist. During the test, a thin needle electrode is inserted into the muscle being tested. The electrode measures the electrical activity of the muscle at rest and during contraction.
Both NCS and EMG are painless and generally safe procedures. They may cause some mild discomfort, but they do not usually cause any long-term effects.