Concentric needle single fiber electromyography: comparative jitter on voluntary-activated and stimulated Extensor Digitorum Communis.

OBJECTIVE To compare the jitter values in voluntarily activated (v-CNE) and stimulated (s-CNE) techniques for Extensor Digitorum Communis muscle using a disposable concentric needle electrode (CNE). Quantifying jitter using a CNE in conjunction with a stimulated technique has not been reported previously. METHODS Forty-one normal subjects were studied, 15 male and 26 female with a mean age of 34.1+/-10.7 years (19-55). The jitter values were expressed as the mean consecutive difference (MCD) of 20 analyzed potential pairs using v-CNE and 30 isolated potentials using s-CNE. RESULTS The mean MCD (n=41) was 23.0+/-2.8 micros for v-CNE and 18.2+/-2.2 micros for s-CNE. The mean jitter of all recorded potentials was 22.9+/-6.7 micros for v-CNE (n=820) and 18.3+/-5.2 micros for s-CNE (n=1230). Upper limits for the 18th (v-CNE) and 27th highest (s-CNE) MCD were 38.9 and 30 micros, respectively (95% confidence limit). The jitter decrease in s-CNE compared to v-CNE was 1:0.79. CONCLUSIONS Our findings of the jitter values using CNE were similar to other published reports using the voluntarily activated technique; however, these are the first described for the stimulated technique using CNE. SIGNIFICANCE The present study confirms that CNE can be used for the stimulated jitter acquisition and measurement, although certain precautions must be taken regarding signal quality, e.g., observing minimal summation.