Comparison of sensory mid-palm studies to other techniques in carpal tunnel syndrome.

This prospective study was done to assess a technique of comparing Median-Ulnar sensory latency differences across the wrist (Sensory Palm [M-U]) to diagnose carpal tunnel syndrome (CTS) and to compare the relative sensitivities of other previously reported techniques: Median-Radial sensory difference (Sensory Thumb [M-R]), Median-Ulnar mixed palm difference (Mix Palm [M-U]) and Median-Ulnar sensory digit difference (Sensory Digits [M-U]). 90 Hands met the electrodiagnostic (EDX) criteria for mild CTS. The Sensory Thumb (M-R) was abnormal in 90% of the hands followed in order by Mix Palm (M-U) 61%, Sensory Digits (M-U) 42% and Sensory Palm (M-U) 33%. All differences were statistically significant (p < .01). Sensory Palm (M-U) did not significantly add to the diagnosis of CTS. The Sensory Thumb (M-R) was relatively the most sensitive followed by Mix Palm (M-R) was relatively the most sensitive followed by Mix Palm (M-U), Sensory Digits (M-U) and Sensory Palm (M-U).