Electrodiagnostic studies, including, nerve conduction studies (NCS), needle electromyography (EMG), and somatosensory evoked potential studies (SSEPs) should be considered an extension of the history and physical examination and not merely a substitute for a detailed neurologic and musculoskeletal examination.
These studies are helpful in the evaluation of patients with limb pain where the diagnosis remains unclear (e.g. perineal neuropathy versus a radiculopathy). They are also helpful in excluding other causes of sensory and motor disturbances, such as peripheral neuropathy and motor neuron disease.
They can also provide useful prognostic information by quantifying the extent and acuity of axonal involvement in radiculopathies.
They can also provide useful prognostic information by quantifying the extent and acuity of axonal involvement in radiculopathies.
Some discomfort may occur as the needle electrodes are inserted. The muscle(s) tested may feel sore after the EMG. The risks are minimal. There may be some minor bleeding and there is a small risk of infection where the needle electrodes are inserted.