2026 Workshop Handout Bundle-W88D EDX Evaluation of the Proximal Limb Nerves

W88D EDX Evaluation of the Proximal Limb Nerves - Meiling Skolka

Pdf Summary

This workshop handout describes nerve conduction study (NCS) techniques for evaluating proximal upper- and lower-limb nerves, with ultrasound as an aid to locating nerves and guiding stimulation. The methods are selected for clinical relevance and practical reproducibility; regular practice is emphasized.<br /><br />Nerves covered include the spinal accessory, axillary, musculocutaneous, phrenic, suprascapular, lateral and medial antebrachial cutaneous, femoral, and lateral femoral cutaneous nerves. The handout explains electrode placement, stimulation, response measurement, troubleshooting, and ultrasound anatomy for each. Motor studies measure CMAP latency, amplitude, and duration; sensory studies measure SNAP onset and peak latencies and amplitude. Some proximal nerves may require caliper-based distance measurement or needle stimulation when surface stimulation is unreliable. Ultrasound can help visualize many nerves, though the axillary nerve is difficult to assess along its full course.<br /><br />General technical guidance includes preparing clean skin, ensuring good electrode contact, keeping limb temperature near 31°C, using standard filter settings, and increasing stimulation until a maximal response is obtained. Sensory responses should be averaged several times. Common sources of error include poor skin contact, low temperature, electrode misplacement, excessive stimulus artifact, movement, and inaccurate distance measurement.<br /><br />The handout notes that side-to-side comparisons are useful for most nerves. It provides reference values for phrenic and lateral femoral cutaneous nerve responses and discusses precautions when performing phrenic stimulation, particularly in patients with external conductive leads near the heart.<br /><br />Three case vignettes illustrate clinical applications: identifying suprascapular neuropathy, supporting lateral femoral cutaneous neuropathy (meralgia paresthetica), and using an abnormal lateral antebrachial cutaneous response to support an upper-trunk brachial plexopathy.

Keywords

nerve conduction study

ncs

ncv

ultrasound guidance

proximal upper limb nerves

proximal lower limb nerves

CMAP

SNAP

phrenic nerve

lateral femoral cutaneous nerve

suprascapular neuropathy

brachial plexopathy