Characteristics of Satellite Potentials in Neuropathies

Sohn, Min Kyun; Bok, Soo Kyung; Kim, Bong Ok

Abstract

OBJECTIVE
This study was carried out to investigate the characteristics of satellite potentials in clinical electromyography. METHOD: A conventional concentric needle electromyography was applied to the biceps brachii and tibialis anterior muscles in 32 normal controls and 14 patients with neuropathies. The satellite potentials were defined as small extrapotentials, preceding or following the main motor unit action potentials(MUAPs) and separated from MUAPs by an isoelectrical interval of at least 1 msec.
RESULTS
In normal controls, the frequency of satellite petentials was 1.27% in the biceps brachii and 1.48% in the tibialis anterior and it was increased in neuropathy by 8.53% (6.7 times of control value) in the biceps brachii and 6.70% (4.5 times of control value) in the tibialis anterior. The satellite potential parameters were not significantly different between the control and neuropathy groups. The amplitude of MUAPs with satellite potentials was significantly higher than that of MUAPs without satellite potentials.
CONCLUSION
The satellite potentials could be used as a valuable and easily obtainable, supplemental electromyographic parameters for the detection of neuromuscular disorders.