Carpal tunnel syndrome is a condition I commonly diagnose utilizing nerve conduction studies. A patient may come in suffering numbness and tingling in his or her hand. To diagnose the condition, I place several electrodes directly over the nerves. Quick electrical pulses are sent through the nerve and the time it takes the pulse to travel down the nerve is recorded. Damage to the nerve is indicated by slow muscle response to the electrical pulse.
An electromyography study can also be used to diagnose pinched nerves in the back or neck that cause radiating pain down the arms or legs. The nerve conduction study is not a painful procedure however it does cause a sensation of mild shocks.
Another test is the electromyogram (EMG). This test is similar to an electrocardiogram (EKG) which records the electrical signals in your heart. An EMG records the electrical signals in other muscles and can help diagnose the cause of muscle weakness caused by injury to the nerves or by neurologic disorders such as ALS. An EMG involves the insertion of a thin needle electrode into the muscle that picks up the electrical activity in the muscle. There can be some discomfort when the needle is inserted but most patients tolerate the test without any problem.