Scoping Review of Diagnostic Strategies for Carpal Tunnel Syndrome and Compressive Median Neuropathy at the Carpal Tunnel

Background Symptoms and pathophysiology are often discordant. To better understand areas of debate regarding diagnosis of carpal tunnel syndrome (CTS) and compressive median neuropathy at the carpal tunnel (CMNCT), we assessed (1) Do studies distinguish CTS (illness) and CMNCT (pathophysiology)? (2) What aspects of diagnosis are evaluated in studies of CTS and CMNCT? and (3) What diagnostic strategies are used for CTS?. Methods We identified 186 consecutive studies that addressed diagnostic strategies for CTS or CMNCT and assessed the aspects of diagnosis addressed, the diagnostic strategies addressed, the distinction between CTS and CMNCT, whether CTS or CMNCT was the subject of study, and the reference standard for CTS or CMNCT diagnosis. Results Seventy studies (38%) distinguished CTS and CMNCT. Most evaluated measures of pathophysiology either in isolation (68%) or combined with other factors (17%). Among the 128 studies that addressed diagnosis of CTS, the majority (66%) used a reference standard that included both symptoms and measures of pathophysiology, and the others used symptoms and signs alone. Discussion In diagnostic experiments, separation of symptoms and pathophysiology has the potential to identify factors associated with their discordance. Better understanding of such discordance could limit misattribution of symptoms to pathophysiology, misdiagnosis, and overtreatment.