P31-F Muscle ultrasound improves fasciculation detection in some muscle in patients with amyotrophic lateral sclerosis

Abstract

Background Fasciculations represent brief spontaneous or triggered contractions of motor units that can be seen as flickering movements under the skin and represent a valuable sign of lower motor neuron lesion. It is sometimes difficult to detect fasciculations clinically and/or electromyografically (EMG). Muscle ultrasound (MUS) is a promising tool that can aid to the better detection of fasciculations. Materials and methods 12 patients (4 females, mean age 68.75 ± 12.04, mean disease duration 4.25 ± 2.09) diagnosed with amyotrophic lateral sclerosis were included in this pilot study. EMG needle was inserted under US guidance into right biceps brachii (BB), first dorsal interousseous (FDI) and rectus femoris (RF) muscles. Location of needle tip was marked and remained stationary during 90 s of recording. Two experienced neurophysiologists independently counted the number of fasciculations from the EMG and MUS recordings. Sperman’s ρ was used to assess interrater reliability. Wilcoxon sign-ranked test was used to compare the number of fasciculations detected by the use of EMG vs. MUS. Results There interrater reliability was excellent (ρ = 0.985, p Conclusions MUS seems to be superior to EMG in detecting and quantifying fasciculations in some, but not all muscles. Further studies are needed to standardize the use of MUS in detecting fasciculations in neurological diseases.