Technical considerations for measurement of median nerve conduction velocity at wrist

Nerve conduction velocity (NCV) testing for the median nerve is the gold standard for diagnosing carpal tunnel syndrome (CTS), which affects about 6% of the general population. However, NCV equipment is relatively expensive and not always available at outpatient clinics. This study investigated the effects of different sampling rates and electrode placements on the NCV values of the median nerve to establish the practical significance of those specifications. The NCV of the median nerve at the wrist was measured in 30 healthy subjects with sampling rates of 2 kHz or 10 kHz and wide or narrow spacing of the electrode; Paired t-tests were used to compare the NCV values acquired by the different testing protocols. We found that the sampling rate had a statistically significant effect on the NCV values (P < 0.01), while the electrode placements did not significantly affect the NCV values (P > 0.05). The findings of this study have implications for improving the cost-effectiveness and technical applicability of NCV instruments.