Grading severity of carpal tunnel syndrome in electrodiagnostic reports: why grading is recommended.

Carpal tunnel syndrome (CTS) is not difficult to confirm by electrodiagnosis (EDx), but the challenge lies in whether to grade the severity and the method for doing so. The arguments about grading are discussed, with an emphasis in favor, using a method that relies on the EDx data, but qualifies that it is the median neuropathy being graded and not the syndrome of CTS. Although use of latencies can be arbitrary and misleading, it is possible to apply other criteria, such as low amplitudes or conduction block and denervation, to develop a grading scale that could be applied widely. Several previously published grading schemes are reviewed, and a new method is described that combines the prior ranking criteria into 3 basic categories. Application of a grading system identifies the degree of nerve injury and thus allows the referring physician to utilize optimally the EDx report to manage the patient.