Neurology India Medknow Publications on behalf of the Neurological Society of India ISSN: 0028-3886 EISSN: 1998-4022 Vol. 58, Num. 2, 2010, pp. 277-279

Neurology India, Vol. 58, No. 2, March-April, 2010, pp. 277-279

Brief Report

A comparative study evoking a sensory action potential from the medial and lateral plantar nerves using the probe and ring method of stimulation

Jamila K Adam, Reneal Bechoo, Wafaa S Rmaih

Department of Biomedical and Clinical Technology, Durban University of Technology, Durban, South Africa

Correspondence Address: Wafaa S Rmaih, Department of Biomedical and Clinical Technology, Durban University of Technology, PO Box-1334, Durban 4000, South Africa, wnsr65@hotmail.com

Date of Acceptance: 02-Nov-2009

Code Number: ni10069

PMID: 20508349

DOI: 10.4103/0028-3886.63768

Abstract

Keywords: Nerve conduction studies, probe method, ring method

Introduction

Two different techniques of stimulation, probe and ring electrode, are used to study the medial and lateral plantar nerve condctions. However, it is not certain which of the methods is superior [Table - 1]. ^[1],[2],[3] The aim of this study was to determine which of the two techniques would be a better techniques in stimulating the medial and lateral plantar nerves.

Materials and Methods

The study subjects included 30 (female 18, male 12) healthy volunteers with no neurological disorders aged between 19 to 55 years. A signed informed consent was obtained from all the participating subjects. The study has the approval of the Ethical Committee of the Durban University of Technology. There were no sources of funding nor, any conflict of interest related to this study. The study period was between January 2008 and August 2008.

Each participant had nerve conduction studies of both the medial and lateral plantar nerves by both the techniques, ring and probe method of stimulation. Nerve conduction studies were done using Nicolet Biomedical Viking IV machine. For measurement of various parameters supramaximal responses were considered.

The active electrode placement of the recording electrodes for both the medial and lateral plantar nerves was as shown in [Figure - 1]. Stimulation using the ring electrode method for both the nerves was as shown in [Figure - 2]a. ^[4] Stimulation using the probe method of stimulation was as shown in [Figure - 2]b. ^[5] Paired T-test was used for statistical analysis.

Results

The mean amplitudes and difference in mean amplitude values of left and right medial plantar nerves, and, left and right lateral plantar nerves using both the ring and probe methods of stimulation are given in [Table - 2]. The mean amplitudes elicited by probe method of stimulation were significantly more than the mean amplitudes elicited by ring electrode method of stimulation for both the nerves: medial plantar nerve 10 ± 8.8 vs. 3.6 ± 2.4 (P< 0.001) and lateral plantar nerve 3.9 ± 2.5 vs. 1.4 ± 0.9 (P< 0.001). With probe method of stimulation discernable responses with good amplitude were elicited with 29 (97%) medial plantar nerve and it was 27 (90%) with later plantar nerve.

Discussion

Our study clearly suggests that the probe method of stimulation of the medial and lateral plantar is a better technique than the ring method of stimulation. The amplitudes of the responses elicited by probe method of stimulation are significantly higher and the chance of obtaining a discernable response is also high. Similar low amplitude responses were elicited by ring electrode method of stimulation in the study by Guiloff et al. ^[6] However, in an another study using ring lectrodes the median planar nerve responses were of higher amplitudes. ^[3] This may probably be related to recording of the responses from the sole of the foot rather than from the ankle [Table - 1]. Similar to our study for the medial and lateral plantar nerves using the probe stimulation technique higher amplitudes were recorded by the antidromic techniques in the study by Kim and colleagues. ^[2] While the studies that used orthodromic studies ^[1],[7] had recorded higher amplitudes than in our study .This may be due to the fact that the stimulation site was the sole of the foot as compared to the base of the great and small toe [Table - 1].

From this study it can be concluded that the probe method of stimulation for both the medial and lateral plantar nerve conduction studies is a more effective method in terms of the amplitudes recorded. Greater amplitudes were constantly achieved when using the probe stimulation method over the ring stimulation method.

References

Copyright 2010 - Neurology India

The following images related to this document are available:

Photo images