Electrodiagnostic tests are usually done to clarify the diagnosis, particularly when clinical findings are inconclusive—for example, To distinguish sensory symptoms due to ulnar nerve palsy from C8 root dysfunction due to cervical radiculopathy To distinguish sensory symptoms due to carpal tunnel syndrome from C6 root dysfunction due to cervical radiculopathy Electrodiagnostic tests also help localize the lesion, assess severity, and estimate prognosis.