On-nerve needle nerve conduction study in the sural nerve: A new technique for evaluation of peripheral neuropathy

Diagnostic markers of axonal degeneration and demyelination in sensory nerve conduction

“…For NCV analysis, we chose NP‐NCV for 2 reasons: the maximum NCV was faster by 2 m/s on SE‐NCS than on ONN‐NCS ( P < 0.0131) . There was no significant difference in NP‐NCV between SE‐NCS and ONN‐NCS (Table ).…”

“…This analysis was based on 84 cases, all of which presented a definite histopathological diagnosis of either axonal degeneration (22 cases), demyelination (50 cases), a combination of both disorders (7), or normal findings (5) on sural nerve biopsy. In 5 patients, ONN‐NCS was not possible due to technical reasons . In 4 patients, the nerve biopsy showed end‐stage atrophy.…”

“…This procedure was performed in the Muscle and Nerve Biopsy Suite in the Electromyography Laboratory at the UAB Medical Center. Details of nerve conduction tests were published previously . Before local anesthesia was administered for the nerve biopsy, the surface electrode NCS (SE‐NCS) was applied antidromically to the sural nerve according to a method described previously to identify the best stimulation site .…”

“…For SE‐NCS, the UAB's normal values for the sural nerve were used . In our previous report, normal values for ONN‐NCS were calculated by multiplying “normal values for the SE‐NCS” by the factor between the 2 techniques . Normal values for SE‐NCS and ONN‐NCS are shown in Table .…”

“…We carried out NCS with a new technique using needle recording electrodes placed on the exposed nerve during sural nerve biopsy. We termed this technique the “on‐nerve needle” (ONN) technique . With this technique, a direct correlation of the nerve conduction data can be made with the histology of the biopsied sural nerve.…”