RESUBMISSION DEPARTMENT NERVE CONDUCTION STUDY GUIEDLINE Most patients are referred for NCS testing with a provisional diagnosis; patients are referred with merely symptoms and/or clinical findings with the expectation that the neurologist will be able to arrive at the correct diagnosis only after the completion of the NCS. When “rule-out” diagnoses are not accepted, only a symptomatic diagnosis (“pain in limb” or “neuralgia and neuritis”) can be coded regardless of the work involved in performing the evaluation for the working diagnosis/provisional diagnosis. Furthermore, NCS testing does not always establish an etiologic diagnosis and may modify the referral diagnosis. A typical NCS examination documentation should include development of a differential diagnosis by the physician based upon appropriate history and physical examination when an etiologic diagnosis is not established. A final diagnosis can be coded if an established diagnosis is established after the completion of the NCS testing with the final interpretation of the study is a synthesis by the neurologist of the patient’s history, physical examination, and the preceding and following portions of the study.