Nerve conduction study of the medial and lateral plantar nerves.

The medial and lateral plantar nerves may be evaluated through the recordings of the compound sensory nerve action potentials (CSNAP), compound mixed nerve action potentials (CMNAP) and compound muscular action potentials (CMAP). As some of these potentials are not easily and always obtainable in normal individuals, our purpose was to verify the consistency of these potentials for the study of these nerves. Fifty-one normal adult volunteers were examined. The CSNAP, CMNAP and CMAP, related to the medial and lateral plantar nerves were evaluated bilaterally. CSNAP were not obtained in 7.8% and in 17.6% from the medial and lateral plantar nerves respectively. CMNAP from the lateral plantar nerve were not obtained in 15.6%. CMNAP from the medial plantar nerves and CMAPs from the abductor hallucis and abductor digiti quinti were obtained for all nerves tested. Our results, therefore, suggest that these last 3 parameters are the ones more reliable for clinical application.