Commentary on Two-Point Discrimination in the Use of Upper Extremity Nerve Function in the AMA Guides

This article responds to the previous article in this issue of The Guides Newsletter (Two-point Discrimination in the Use of Upper Extremity Nerve Function in the AMA Guides) and discusses why the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Sixth Edition, has chosen to retain the use of static two-point discrimination for both acute single incident digital nerve injury and for upper extremity focal entrapment neuropathy. The authors clarify that the AMA Guides, Sixth Edition does not use two-point discrimination as a diagnostic criterion for entrapment neuropathy such as carpal tunnel syndrome. Instead, it uses two-point discrimination as a criterion to judge severity, specifically to help select the proper integer for the rating to be assigned for the diagnosis determined by other criteria. Two-point testing is not sensitive but is specific to significant nerve impairment (ie, severity, not diagnosis), and the authors note its advantages of being familiar to most impairment examiners, having a basis in published literature, having variations of the testing protocol that help “objectify” the apparent sensory deficit, and correlating with severity. Thus, if a rating is to be done “according to the AMA Guides,” two-point discrimination remains a required and important part of assessment of the upper extremity neurologic impairment of the hand.