Electrodiagnostic approach to the patient with suspected radiculopathy.

Cervical and lumbosacral radiculopathies are among the most common causes of referral to the electromyographic (EMG) laboratory. Among all the other electrodiagnostic studies (nerve conduction studies, late responses, somatosensory evoked potentials, root electrical and magnetic stimulation studies), the needle electrode (needle EMG) examination is the most specific and sensitive. A good grasp of the anatomic, clinical and electromyographic myotomal charts is essential to localize radiculopathies to single (or more) root lesions.