This test involves checking the nerves and muscles of the patient. It is the whole procedure and is usually done at specialized centers with prior appointment. Nerve conduction studies (NCS) involve attaching certain leads to limbs of patient. Patient may have unpleasant feeling of electrical currents during the test. Electromyography (EMG) involves insertion of needle in different muscle groups and patient may find this procedure painful. This procedure may take 30 to 40 minutes.