Optimum trace count necessary for jitter calculation in single-fiber electromyography

BASLO M. B., Yalinay P., Yildiz N., Ertas M.

ACTA NEUROLOGICA SCANDINAVICA, vol.108, no.4, pp.262-266, 2003 (SCI-Expanded) identifier identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 108 Issue: 4
  • Publication Date: 2003
  • Doi Number: 10.1034/j.1600-0404.2003.00120.x
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.262-266
  • Keywords: single-fiber electromyography, jitter myasthenia gravis, voluntary contraction single-fiber electromyography, electromyography, EMG REFERENCE VALUES
  • Acibadem Mehmet Ali Aydinlar University Affiliated: No


Objective - To clarify the optimum trace count for jitter calculation. Materials and methods - Single-fiber electromyography was performed during voluntary contraction (VC-SFEMG) of extensor digitorum muscle in six healthy and five myasthenic subjects. Twenty single-fiber action potential (SFAP) pairs were recorded from each subject. For each pair, 100 consecutive traces were recorded and stored for off-line analysis. Ten different jitters were calculated in 10 consecutive steps for each SFAP pair by increasing the number of traces included to analysis ( from 10 to 100). The jitter calculated in each step was compared with that calculated from 100 traces. Results - Sixty was the optimum number of trace count for both myasthenics and normal controls. Using less than 60 traces for jitter calculation revealed lower values. Conclusion - Jitter calculation should be performed from at least 60 traces in VC-SFEMG. Less numbers yield lower jitter and may cause diagnostic error.