Evaluation of the scratch collapse test for the diagnosis of carpal tunnel syndrome.

This prospective study measured and compared the diagnostic performance characteristics of various clinical signs and physical examination manoeuvres for carpal tunnel syndrome (CTS), including the scratch collapse test. Eighty-eight adult patients that were prescribed electrophysiological testing to diagnose CTS were enrolled in the study. Attending surgeons documented symptoms and results of standard clinical manoeuvres. The scratch collapse test had a sensitivity of 31%, which was significantly lower than the sensitivity of Phalen's test (67%), Durkan's test (77%), Tinel's test (43%), CTS-6 lax (88%), and CTS-6 stringent (54%). The scratch test had a specificity of 61%, which was significantly lower than the specificity of thenar atrophy (96%) and significantly higher than the specificity of Durkan's test (18%) and CTS-6 lax (13%). The sensitivity of the scratch collapse test was not superior to other clinical signs and physical examination manoeuvers for CTS, and the specificity of the scratch collapse test was superior to that of Durkan's test and CTS-6 lax. Further studies should seek to limit the influence of a patient's clinical presentation on scratch test performance and assess the scratch test's inter-rater reliability.

Changes in treatment plan for carpal tunnel syndrome based on electrodiagnostic test results.

This study evaluated how often the treatment plan for carpal tunnel syndrome (CTS) changed based on electrodiagnostic test results. Secondly, we assessed factors associated with a change in the treatment plan for CTS. One-hundred-and-thirty English-speaking adult patients underwent electrodiagnostic testing in a prospective cohort study. Treatment plan was recorded before and after testing. Treatment plan changed in 25 patients (19%) based on electrodiagnostic test results. The plan for operative treatment before testing decreased significantly after testing (83% versus 72%). The best logistic regression model for no change in treatment plan included a prolonged or non-recordable median distal sensory latency (normal, prolonged, or non-recordable), and explained 24% of the variation. For surgeons that manage CTS on the basis of objective pathophysiology rather than symptoms, electrodiagnostic test results often lead to changes in recommended treatment.

Correspondence between clinical presentation and electrophysiological testing for potential carpal tunnel syndrome.

The diagnosis of carpal tunnel syndrome (CTS) is often applied in the absence of objectively verifiable pathophysiology (i.e. electrophysiologically normal carpal tunnel syndrome). The primary purpose of this study was to determine whether depressive symptoms, heightened illness concern, and pain catastrophizing are associated with an absence of electrophysiological abnormalities. The secondary purpose was to examine the correspondence between the Levine scale, the CTS-6, and electrophysiological abnormalities. Ninety-eight participants completed validated questionnaires assessing psychosocial factors at the initial visit, and surgeons recorded clinical data and their confidence that the diagnosis was carpal tunnel syndrome. Symptoms and signs that are characteristic of carpal tunnel syndrome (e.g. the CTS-6 and Levine scale) significantly, but incompletely coincided with electrophysiological testing. Psychological factors did not help distinguish patients with normal and abnormal objective testing and it remains unclear if symptoms that do not coincide with abnormal tests represent very mild, immeasurable median nerve dysfunction or a different illness altogether. Future studies should address whether outcomes are superior and resource utilization is optimized when surgery is offered based on symptoms and signs (e.g. the CTS-6) or when surgery is offered on the basis of measurable pathophysiology.