Reference voluntary jitter values using disposable monopolar needle electrodes in the extensor digitorum communis muscle

To measure normal variability in neuromuscular transmission in the extensor digitorum communis (EDC) muscle voluntarily activated using a disposable monopolar needle electrode (MNPE).

We examined the EDC muscle using MNPE in 50 healthy volunteers (12 male and 38 female, mean age: 41.5+/-12.9 years, age range: 18-74 years). The high-pass filter setting was 3 kHz.

Jitter values are expressed as the mean consecutive difference (MCD) of 20 potential pairs. Mean MCD (n=50) was 21.3+/-3 micros (upper 95% confidence limit (CL): 27.3 micros). Mean MCD in all potential pairs (n=1000) was 21.3+/-6.6 micros (upper 95% CL: 34 micros). Mean MCD for the 18th highest value was 28+/-4.7 micros (upper 95% CL: 37.5 micros).

The suggested practical upper limit for mean MCD was set to 28 micros; for outliers it was 38 micros.

The present study defines the normative value for jitter recorded with disposable MNPE, which is a low-cost alternative for the evaluation of neuromuscular transmission, although certain precautions must be taken.