Reproducibility of sensory nerve conduction studies of the sural nerve using ultrasound-guided needle positioning.

Background: In this study we sought to evaluate the reproducibility of sensory nerve conduction studies (NCS) using ultrasound-guided needle positioning (USNP).

Methods: Orthodromic NCS of the sural nerve using needle electrodes with USNP as well as surface electrodes were conducted twice in 20 healthy volunteers.

Results: The mean sensory nerve action potential (SNAP) amplitude in the initial examination was 39.5 μV using needle electrodes with USNP, and 12.5 μV using surface electrodes (P < 0.0001). The mean SNAP amplitude in the follow-up examination was 39.2 μV using needle electrodes with USNP, and 12.4 μV using surface electrodes (P < 0.0001). The mean intraindividual change in SNAP amplitude (test-retest) was 21.2% using needle electrodes with USNP, and 24.8% using surface electrodes (P = 0.6).

Conclusions: Sensory NCS of the sural nerve using needle electrodes with USNP have reliable test-retest reproducibility and yield greater SNAP amplitudes than sensory NCS using surface electrodes.