Comparison of Relationship Between the Results of Semmes-Weinstein Monofilament Test and Nerve Conduction Studies in Patients Suffering Carpal Tunnel Syndrome

Carpal tunnel syndrome(CTS) is the most common compression neuropathy. There are many methods for evaluation of CTS. Nerve conduction study(NCS) and Semmes-Weinstein monofilament(SWMs) test are sensitive tests for CTS evaluation, but the correlation between two methods has not been evaluated. The purpose of this study was to study the relationship between the results of SWMs test and NCS on women with CTS. Samples were 56 hands in 33 women with CTS at age of 20-73 years. SWMs test and measurement of secondary variables was done by an occupational therapist and NCS by a physiatrist. Our research method was analytical nonintervention. Variables were: age, BMI, hand length, hand width, length of distal phalanx of thumb, index and middle fingers, distal sensory latency, distal motor latency, sensory and motor amplitude, nerve conduction velocity(NCV), Semmes-Weinstein monofilament and the results of three fingers severity. Data were analyzed by simple regression test and one-way variance analysis. There was a significant relationship between results of SWMs test and NCV(P=0.0002), distal sensory latency(DSL)(P<0.00001), amplitude of sensory(Amps) NCV(P<0.00001), distal motor latency(DML)(P<0.00001) and amplitude of motor NCV(P=0.0042) which was most obvious in the thumb. There was a negative correlation between SWMs test and NCV, Amps, Ampm and there was a positive correlation between SWMs test and DSL, DML. There was a significant positive correlation between SWMs test and severity this positive correlation was more significant in the thumb than in the other two fingers. Hand dominance did not have any significant correlation with SWMs test and NCS. There is more significant relationship between SWMs test and NCS in evaluation of the first finger which is most probably because the first finger has large area in brain mapping.