"Facial" and standard concentric needle electrodes are not interchangeable.

Area of Science:

• Neurology
• Electrophysiology
• Biomedical Engineering

Background:

• Accurate recording of motor unit action potentials (MUAPs) is crucial for diagnosing neuromuscular disorders.
• Needle electrode selection can influence electromyography (EMG) signal characteristics, including amplitude and duration.
• Understanding these differences is vital for consistent and reliable EMG assessments.

Purpose of the Study:

• To compare the performance of standard concentric needle (SCN), facial concentric needle (FCN), and monopolar needle (MN) electrodes in recording MUAPs.
• To evaluate the impact of different needle types on MUAP amplitude and duration in specific muscles.
• To determine the interchangeability of these electrodes for EMG amplitude analysis.

Main Methods:

• MUAPs were recorded from the biceps brachii and first dorsal interosseous manus muscles of 7 healthy subjects.
• Three needle types were used: SCN, FCN, and MN.
• Analysis focused on MUAP duration and amplitude across the different electrode types.

Main Results:

• MUAP durations were comparable across all electrode types for each muscle.
• The FCN electrode recorded significantly higher amplitude MUAPs more frequently than the SCN electrode.
• While FCN and MN showed similar patterns of amplitude and duration changes, their uptake areas differed.

Conclusions:

• The FCN and SCN electrodes are not interchangeable for assessing EMG signal amplitude due to amplitude recording differences.
• Electrode type influences MUAP amplitude, necessitating careful selection for diagnostic accuracy.
• Different needle electrodes possess distinct signal acquisition characteristics impacting EMG interpretation.