Simple and novel method to measure distal sensory nerve conduction of the medial plantar nerve

Abstract

A simple and reliable method for recording sensory nerve action potentials (SNAPs) of the medial plantar nerve is described. Medial plantar SNAPs were recorded by placing surface electrodes on the sole. Ring electrodes were used for orthodromic stimulation at the big toe. Sixty-four healthy subjects ranging in age from 13 to 81 years were examined to establish normal values. Mean amplitude for the medial plantar SNAP was 4.7 +/- 2.8 microV and mean maximum conduction velocity was 43.5 +/- 6.4 m/s. The normal values for amplitude obtained for the medial plantar SNAPs were higher than those obtained by the method of Guiloff and Sherratt, and the sensitivity of our method for diagnosis of early sensory neuropathy was relatively higher. The method should therefore be useful in the diagnosis of early sensory neuropathy.

Electrophysiological markers of large fibre sensory neuropathy: a study of sensory and motor conduction parameters

“…It is noteworthy that recording of these parameters involves only technically straight‐forward, easy and rapid procedures, currently already performed in most laboratories routinely. Although other techniques have been described as useful in this setting [15,17,27], these are not utilized widely, and their reliability remains uncertain particularly in older patients [18]. Our results confirm some previous findings whilst raising questions about others, and consequently provide additional reasons for further study.…”

“…In addition, previous literature suggests that up to 40% of healthy subjects over 60 years, i.e. when most likely to suffer from neuropathy, may not have detectable medial plantar SNAPs [2,16,17]. Sensitivity of the SRAR in Sullivan et al.…”

The realistic yield of lower leg SNAP amplitudes and SRAR in the routine evaluation of chronic axonal polyneuropathies

“…Above the age of 60 the medial plantar SNAP can be absent in up to 40 % of asymptomatic healthy controls [37,42,43]. Since polyneuropathy mainly af-f f fects elderly people and medial plantar nerve conduction studies are technically demanding and unpleasant for the patient, the utility of this method in routine clinical practice could be limited.…”

Whole plantar nerve conduction study with disposable strip electrodes

“…For recording medial plantar SNAPs, surface electrodes were placed on the sole, and stimulating electrodes were placed at the big toe. The mean amplitude of SNAPs obtained by our method was higher than that of SNAPs obtained by using Guiloff's method . However, recording of SNAPs by either method might not be possible in all persons older than 60 years of age, even in normal subjects.…”

“…These methods are, therefore, rarely used for routine clinical studies. In our previous reports, we described a new method for measuring distal sensory nerve conduction of the medial plantar nerve. For recording medial plantar SNAPs, surface electrodes were placed on the sole, and stimulating electrodes were placed at the big toe.…”