Sensitivity and specificity of carpal tunnel syndrome signs

The sensitivity and specificity of six carpal tunnel syndrome (CTS) signs were determined by evaluating 143 subjects (228 hands) with symptoms of CTS. Immediately after performing the six physical examination tests, standard nerve conduction studies were performed on all 228 hands to determine the presence or absence of CTS. CTS was present in 142 hands and absent in 86 hands. The signs were not very sensitive (23-69%), but were fairly specific (66-87%) for CTS. A square-shaped wrist and abductor pollicis brevis weakness were the most sensitive signs (69 and 66%, respectively), and are recommended as part of the examination of CTS. Median nerve hypesthesia and the Phalen sign both have fair sensitivity (51%) but good specificity (85 and 76%, respectively). The median nerve compression sign and the Hoffmann-Tinel sign both have poor sensitivity (28 and 23%, respectively), and thus are less helpful in evaluating subjects with suspected CTS.