Count of Fasciculation in Ultrasound Can Predict the Prognosis of Amyotrophic Lateral Sclerosis

Background: Although muscle ultrasound (MUS) is known to facilitate the diagnosis and evaluation of the severity of amyotrophic lateral sclerosis (ALS), the number of fasciculation has been scarcely examined as a predictive marker of the prognosis in ALS. Objective: The objective of this study was to examine the predictive value of fasciculation number for the prognosis of ALS. Materials and Methods: We examined fasciculation count (FasC), defined as the number of fasciculation per unit of time and area in MUS, of 11 patients with clinically probable or definite ALS. Thereafter, they were observed for maximally 2 years, unless they reached the endpoint of decease or receiving tracheostomy. Results: Six patients, who thereafter reached the endpoint within 2 years, had significantly higher FasC (223 [49.3] vs. 34 [13], P = 0.0043) and shorter disease duration (7 [2.3] vs. 33 [17], P = 0.0022) at MUS than the remaining five patients without reaching the endpoint. Discussion and Conclusion: Our study suggested that high FasC in MUS can predict rapid progression in ALS. Due to the limitations such as small sample size, suboptimal length of the observational period, and confounding factor of disease duration, further investigations are required.