Complex fasciculation potentials and survival in amyotrophic lateral sclerosis

• Complex fasciculation potentials (FPs) in ALS are more frequently observed in muscles with normal strength or mild weakness.
• ALS patients with complex FPs have poorer survival periods than those without complex FPs.
• Wide distribution of complex FPs predicts shorter survival in ALS.

ObjectiveWe investigated the relationship between fasciculation potentials (FPs) and survival in patients with ALS.MethodsIn 85 ALS patients, we prospectively performed needle EMG in five to seven muscles of each patient. The shape of the detected FPs was analyzed by inspection, and FPs with >4 phases were judged as complex FPs. We analyzed the correlation between complex FPs and survival period using the Cox proportional hazard model.ResultsComplex FPs were observed in 47 patients, more frequently in the muscles with normal strength or mild weakness. The presence of complex FPs was associated with shorter survival (hazard ratio 3.055; p = 0.004). The greater the number of muscles with complex FPs, the shorter the survival and the faster the progression speed.ConclusionWide distribution of complex FPs is associated with shorter survival in ALS.SignificanceComplex FPs are useful to predict prognosis of ALS patients and should be evaluated in the EMG examination.