Sonographic Measurement of Median Nerve Cross-Sectional Area to Determine Severity of Carpal Tunnel Syndrome: A Cautionary Tale.

Using median nerve CSA to categorize the severity of CTS is not recommended based on lack of consistent and meaningful shifts in diagnostic probability. Rather, binary categorizations to rule out or rule in CTS based on the proposed CSA cutoff values consistently provided conclusive shifts in diagnostic probability across all EDX-based classifications examined.