The long thoracic nerve conduction study revisited in 2006.

Area of Science:

• Neurophysiology
• Clinical Electrophysiology
• Nerve Conduction Studies

Background:

• Accurate assessment of long thoracic nerve (LTN) function is crucial for diagnosing conditions affecting the serratus anterior muscle.
• Traditional nerve conduction studies (NCS) for the LTN have utilized various electrode types, each with potential limitations.
• Comparing the reliability and feasibility of different recording techniques is essential for optimizing diagnostic protocols.

Purpose of the Study:

• To compare the reliability and feasibility of recording long thoracic nerve (LTN) conductions using surface electrodes versus needle electrodes.
• To evaluate the clinical utility of both techniques in control subjects and their potential application in pathological cases.

Main Methods:

• Bilateral nerve conduction studies of the LTN were performed on 40 control subjects.
• Stimulation at the axilla with surface recording on the serratus anterior (SA).
• Stimulation at Erb's point with needle recording in the SA, measuring latency and amplitude.

Main Results:

• Both surface and needle electrode techniques yielded reliable responses in all subjects.
• Surface recording showed a mean latency of 2.2 ms and amplitude of 5.3 mV.
• Needle recording demonstrated a mean latency of 3.65 ms and amplitude of 8.95 mV.

Conclusions:

• Both surface and needle electrode methods for LTN conduction are reliable and feasible, correlating well.
• Surface recording is recommended for routine examinations due to being non-traumatic and patient-friendly.
• In pathological conditions, utilizing both techniques is advised for comprehensive assessment of axonal loss and nerve conduction impairment.