A Proximal Conducting Technique of Sural Nerve

ABSTRACT

OBJECTIVE: The sural nerve is a sensory nerve in the lower extremity which is formed by the union of the medial sural cutaneous nerve of tibial nerve and the communicating branch of the common peroneal nerve. The objective of this study is to standardize the electrodiagnostic technique of proximal conduction of sural nerve and to investigate the usefulness of the technique in evaluation for the patients with peripheral neuropathy. METHOD: Fifty eight extremities in 29 normal adults without the clinical signs and symptoms of peripheral neuropathy were evaluated with sural nerve conduction study. The active recording electrode was placed over 14 cm proximal to the lateral malleolus, and the reference electrode was placed over 4cm distal to the active electrode. The antidromic evoked responses were recorded with stimulation at points 7, 14, 21 cm proximal to the recording electrode and directly over the sural nerve. RESULTS: The mean values of proximal conduction study of sural nerve in normal adults were 2.40 1.03 msec for peak latency, 11.55 +/-7.31 microvolt in amplitude with stimulation at 7 cm proximal to the recording electrode; 3.43 +/-0.78 msec for peak latency, 10.87 5.86 microvolt in amplitude with stimulation at 14 cm; 4.51 +/-0.83 msec for peak latency, 8.78+/- 4.10 microvolt in amplitude with stimulation at 21 cm. CONCLUSION: A method of proximal conduction study of sural nerve was introduced which could be used as a valuable technique for the evaluation of peripheral neuropathy.