To set up a reference limit for stimulated single fiber electromyography (s-SFEMG), 19 healthy subjects and 20 myasthenic patients were enrolled in the present study. All participants received s-SFEMG in extensor digitorum communis muscle (EDC) at stimulation frequency of 1, 2, 5, and 10 Hz. The mean consecutive difference (MCD) was calculated from 100 potentials to represent the jitter. Results showed distributions of normal jitter with respect firing rate were 19.5 ± 9.0, 19.7 ± 9.0, 22.1 ± 8.7, 21.2 ± 8.6 μsec for individual MCD (i-MCD), and 19.7 ± 4.7, 19.9 ± 4.6, 22.4 ± 4.7, 20.9 ± 3.4 μsec for mean MCD (m-MCD). Evaluating the MCD values obtained from myasthenic patients, given normal limits defined by the distribution of jitter in healthy subjects, we obtained high diagnostic sensitivity and a low false positive rate at 10 Hz. We proposed an adequate upper reference limit of 41 μsec for i-MCD and 29 μsec for m-MCD, for s-SFEMG in EDC at 10 Hz stimulation.
|Number of pages||6|
|Journal||Acta Neurologica Taiwanica|
|Publication status||Published - 1997 Dec 1|
All Science Journal Classification (ASJC) codes
- Clinical Neurology