This evidence-based review was performed to evaluate the utility of nerve conduction studies (NCSs) and needle electromyography (EMG) in the diagnosis of tibial neuropathy at the ankle (tarsal tunnel syndrome, TTS). A total of 317 articles on TTS were identified that were published in English from 1965 through April 2002, from the National Library of Medicine MEDLINE database. All articles were reviewed on the basis of six selection criteria. The results of this search revealed that four articles met five or more criteria. All four articles examined the use of electrodiagnostic (EDX) techniques for the evaluation of patients with clinically suspected TTS, and were included in this practice parameter. Each of these four studies was considered to meet Class III level of evidence. NCSs were abnormal in some patients with suspected TTS. Sensory NCSs were more likely to be abnormal than motor NCSs but the actual sensitivity and specificity could not be determined. The sensitivity of needle EMG abnormalities could not be determined. NCSs may be useful for confirming the diagnosis of tibial neuropathy at the ankle, recommendation Level C. Well-designed studies are needed to evaluate more definitively EDX techniques in TTS.

No abstract

We report a new technique for studying conduction in the medial calcaneal nerve (MCN). Dissection of 14 cadaver feet revealed the optimal G1 site to be one third of the way from the apex of the heel to a point midway between the navicular tuberosity and the prominence of the medial malleolus. Seventy-two feet (36 healthy volunteers) were studied using surface stimulation of the tibial nerve 10 cm proximal to the G1 surface electrode. Averaging technique was not required. Reference values (mean +/- 2 SD) were determined for MCN onset latency (2.0 +/- 0.3 ms), peak latency (2.5 +/- 0.3 ms), onset conduction velocity (61 +/- 11 m/s), peak conduction velocity (40 +/- 5 m/s), baseline-to-peak amplitude (18 +/- 6 microV), and maximum intrasubject side-to-side differences in these values (0.3 ms, 0.3 ms, 15 m/s, 5 m/s, and 17 microV, respectively). This study provides an easily performed, reproducible method for electrophysiologic evaluation of the MCN.

No abstract