Reference jitter values for concentric needle electrodes in voluntarily activated extensor digitorum communis and...

Area of Science:

• Neurology
• Electromyography
• Clinical Neurophysiology

Background:

• Jitter analysis is crucial for diagnosing neuromuscular disorders.
• Normal jitter values are essential for interpreting abnormal findings.
• Disposable concentric needle electrodes (CNE) offer a practical approach to electrophysiological assessments.

Purpose of the Study:

• To estimate normal jitter values in voluntarily activated extensor digitorum communis (EDC) and orbicularis oculi (OOc) muscles.
• To establish reference ranges for jitter using a disposable concentric needle electrode (CNE).
• To provide practical upper limits for mean consecutive difference (MCD) jitter values in EDC and OOc muscles.

Main Methods:

• Jitter was measured in 67 subjects for EDC and 50 subjects for OOc.
• Disposable concentric needle electrodes (CNE) were used for voluntary muscle activation.
• Jitter values were quantified as the mean consecutive difference (MCD) of 20 potential pairs.

Main Results:

• The mean MCD for EDC jitter was 23.6 ± 3.1 µs (95% CL: 29.7 µs).
• The mean MCD for OOc jitter was 24.7 ± 3.1 µs (95% CL: 31.0 µs).
• Suggested practical limits for EDC were 30 µs (mean MCD) and 42 µs (outliers); for OOc, 31 µs (mean MCD) and 41 µs (outliers).

Conclusions:

• Disposable concentric needle electrodes (CNE) can reliably assess jitter in EDC and OOc muscles.
• The study provides the largest series of CNE jitter values during voluntary activation to date.
• Precautions are necessary when using CNE for jitter assessment to ensure accurate results.