P296 Study of single fiber electromyography using concentric needle in healthy subjects

Abstract

Objectives single fiber electromyography using concentric needle (SFCN) is used increasingly for the diagnosis of neuromuscular junction disorders. It was forced respects of legal order restricted re-use of sterilized material in medicine and the need to reduce the cost of examination. Introduction concentric needles made it necessary for creation reference values for jitter measured with it. The aim of this study was to create reference values for jitter measured with concentric needle electrodes in healthy people. Methods We collected at least 20 pairs of potentials during minimal voluntary activation of frontalis muscle. These potentials were selected that had a minimal number of components, well-defined peak, however, the amplitude must exceed 100 uV. We tested 28 people, 22 women and 6 men, mean age was 51.7 ± 15.4. The jitter values of action potentials pairs of isolated muscular fibres were expressed as the mean consecutive difference (MCD) and also as the mean of sorted intervals (MSD) after 20 analysed potential pairs. Results The mean value of jitter was MCD 22.9 ± 3.9 ms (range 17–31), MSD 24.9 ± 4.2 ms (range 18–37). Conclusions The results obtained are similar to those reported by other authors, and related to values obtained using a SF needle. Significance SFCN performed by the concentric needle is reliable.