Comparison of the modified method and the median sensory-ulnar motor latency difference in the diagnosis of carpal tunnel syndrome.

OBJECTIVES

This study aimed to compare the modified method and the median sensory-ulnar motor latency difference in the diagnosis of carpal tunnel syndrome.

METHODS

The study recruited the electromyography results of 105 hands of 60 patients who had a complaint of carpal tunnel syndrome (CTS) on the hand diagram. The average sensory-ulnar motor delay difference (MSUMLD) was determined by simple subtraction, and the modified method was calculated based on the results of the classic method. The modified method and the MSUMLD were compared according to their sensitivity and specificity in the diagnosis of CTS.

RESULTS

In this study, 54 hands were evaluated with a unilateral nerve conduction study (45 right; 9 left). A total of 23 hands with CTS and 31 hands without CTS were diagnosed electrophysiologically. The MSUMLD had 91.3% sensitivity and 93.5% specificity; however, the modified method showed 95.7% sensitivity and 96.8% specificity in the diagnosis of CTS. Moreover, the modified method had 100% sensitivity and specificity in the diagnosis of moderate CTS.

CONCLUSIONS

The modified method may have higher diagnostic accuracy than the MSUMLD for diagnosing CTS.