Thoracic paraspinal muscle concentric needle electrode jitter analysis in electrophysiological diagnosis of ALS

Objectives

Jitter analysis with concentric needle electrode of the thoracic 9 (T9) paraspinal muscle (PM), where the needle EMG examination at rest is difficult, was performed in both amyotrophic lateral sclerosis (ALS) patients and the controls.

Methods

For the T9 PM, both upper limit for mean and individual mean consecutive difference (MCD) values and spike numbers were calculated according to jitter values of pairs from controls. In addition to the descriptive statistics, differences between two groups and T9 PM needle EMG and jitter analysis findings of patients were compared (p = 0.05).

Results

Mean MCD median values of T9 PM were 62.8 and 26.2 µs in patient and controls respectively. Upper limit of mean and individual MCDs for the T9 PM were determined as 36.95 μs, 57.95 μs respectively. The differences between controls and patients in terms of all jitter analysis parametres (p < 0.001) and the comparison of patients’ T9 PM needle EMG and jitter analysis findings grading were statistically significant (p = 0.029).

Conclusion

The T9 PM jitter analysis performed during routine EMG can be used to support the electrophysiological diagnosis of ALS in challenging cases and may contribute to minimizing the number of muscles examined. Furthermore, our study contributed to the T9 PM reference values for jitter analysis.