Fasciculation potentials and decremental responses in amyotrophic lateral sclerosis

Publication date: February 2018
Source:Clinical Neurophysiology, Volume 129, Issue 2
Author(s): Yosuke Miyaji, Yuki Hatanaka, Mana Higashihara, Takamichi Kanbayashi, Fumiaki Tanaka, Masahiro Sonoo
ObjectiveThe positive correlation between fasciculation potentials (FPs) and decremental responses in repetitive nerve stimulation test (RNS) in amyotrophic lateral sclerosis (ALS) patients has been described based on only one past study. We revisited this issue.MethodsSubjects consisted of 30 prospectively-enrolled ALS patients on whom both needle EMG and RNS were conducted in the same trapezius muscle. Fasciculation potentials (FPs) were identified off-line from the restored 3-min signal. Firing rate of FPs (FR-FP) per minute was calculated from the total count of FPs of different origins. Correlations between FR-FP, decremental percentage (Decr%) and the amplitude of the initial compound muscle action potential (CMAPamp) in RNS were investigated.ResultsThere was no correlation between FR-FP and Decr% (r = 0.03) or between FR-FP and CMAPamp (r = 0.04). A significant negative correlation was observed between CMAPamp and Decr% (r = −0.56, P < .005).ConclusionFPs are not correlated with the decremental response in RNS.SignificanceThe underlying mechanism for FPs and decremental responses in ALS must be different and unrelated to each other.



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