Article

Antidromic sensory nerve conduction studies of medial and lateral plantar nerves in normals

Department of Physical Medicine and Rehabilitation, Wayne State University, Detroit.
Electromyography and clinical neurophysiology 01/1993; 33(5):289-94.
Source: PubMed

ABSTRACT

A reliable sensory nerve conduction study for the most distal lower extremities is needed in routine clinical electromyography. This paper reports a study of 150 medial and lateral plantar nerves in the foot in normals. An antidromic technique was used with stimulation at the ankle and recording from the small and large toes. Recordable responses were obtained in 149 instances. Conduction velocity in the medial branch distal to the tarsal tunnel was 40.5 +/- 4.0 m/sec and significantly slower than conduction in the lateral branch by 4.3 m/sec. The amplitude of the evoked response from the big toe was 3.46 +/- 2.2 microV and significantly larger than that in the small toe by 1.34 microV. Evoked response amplitude in the medial branch was greater in younger subjects.

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    • "Tibial sensory conduction values also need to be evaluated in patients with possible tarsal tunnel syndrome complaints [13,20]. Updated normative values have been published for both antidromic [21,22] and orthodromic medial and lateral plantar sensory techniques [23,24]. There are, however, few well controlled studies using adequate sample sizes to establish normative data for tibial sensory nerve conduction values. "
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    ABSTRACT: Standard tibial motor nerve conduction measures are established with recording from the abductor hallucis. This technique is often technically challenging and clinicians have difficulty interpreting the information particularly in the short segment needed to assess focal tibial nerve entrapment at the medial ankle as occurs in posterior tarsal tunnel syndrome. The flexor hallucis brevis (FHB) has been described as an alternative site for recording tibial nerve function in those with posterior tarsal tunnel syndrome. Normative data has not been established for this technique. This pilot study describes the technique in detail. In addition we provide reference values for medial and lateral plantar orthodromic sensory measures and assessed intrarater reliability for all measures. Eighty healthy female participants took part, and 39 returned for serial testing at 4 time points. Mean values ± SD were recorded for nerve conduction measures, and coefficient of variation as well as intraclass correlation coefficients (ICC) were calculated. Motor latency, amplitude and velocity values for the FHB were 4.1 ± 0.9 msec, 8.0 ± 3.0 mV and 45.6 ± 3.4 m/s, respectively. Sensory latencies, amplitudes, and velocities, respectively, were 2.8 ± 0.3 msec, 26.7 ± 10.1 μV, and 41.4 ± 3.5 m/s for the medial plantar nerve and 3.2 ± 0.5 msec, 13.3 ± 4.7 μV, and 44.3 ± 4.0 msec for the lateral plantar nerve. All values demonstrated significant ICC values (P ≤ 0.007). Motor recording from the FHB provides technically clear waveforms that allow for an improved ability to assess tibial nerve function in the short segments used to assess tarsal tunnel syndrome. The reported means will begin to establish normal values for this technique.
    Full-text · Article · May 2011 · Journal of Foot and Ankle Research
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    ABSTRACT: Tarsal Tunnel Syndrome (TTS) can be difficult to diagnose: electrophysiologic corroboration is important and has therapeutic implications. Conventional electrodiagnostic techniques are insensitive: motor latency abnormalities exist in only 52%; sensory responses are frequently absent (a nonlocalizing finding). Additionally, previously described near nerve techniques do not isolate conduction velocity (CV) measurement to the short segment across the flexor retinaculum (FR), which would theoretically improve sensitivity. We describe a technique which allows for the determination of segmental sensory CVs of the medial (MP) and lateral (LP) plantar nerves, both below (BFR) and across (AFR) the FR. Seventeen normal patients (age 22-45) were studied. Near nerve recording electrodes were positioned close to the specified nerve below and above the FR. Ring electrode stimulation (RES) of digits I (MP) or V (LP) and direct near nerve stimulation (NNS) BFR were performed. With RES digit I (n = 17), mean CV (toe to BFR) was 39.0 +/- 7.1 m/s; CV (AFR) 47.9 +/- 6.2 m/s. CV (AFR) following NNS (MP) (n = 16) was 49.4 +/- 5.1 m/s. With RES digit V (n = 10), mean CV (toe to BFR) was 36.4 +/- 3.4 m/s; CV (AFR) 57.5 +/- 6.9 m/s. CV (AFR) with NNS (LP) (n = 14) was 59.8 +/- 6.2 m/s. In conclusion, segmental MP and LP sensory CVs can be reliably obtained with near nerve technique. This approach may improve the diagnostic sensitivity of EMG in TTS.
    No preview · Article · Oct 1996 · Electromyography and clinical neurophysiology
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    ABSTRACT: Rare distal compressions of lower limb nerves include tarsal tunnel syndrome, entrapment of the first branch of the lateral plantar and medial calcaneal nerves, interdigital neuroma, compression of the deep peroneal nerve on the dorsum of the foot, entrapment of the superficial peroneal and sural nerves. Nerve conduction and electromyographic studies are essential to evaluate these peripheral nerve injuries in order to differentiate focal lower extremity nerve entrapments from ischemic mononeuropathies, lumbar radiculopathies or plexopathies, and generalized peripheral neuropathies. This review summarizes the clinical and electrophysiological findings for each of these rare entrapment syndromes and provides the necessary clues to obtain a correct differential diagnosis with other more common causes of foot and ankle pain and paresthesias.
    No preview · Article · Dec 1997 · Neurophysiologie Clinique/Clinical Neurophysiology
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