Related Experiment Video
Updated: May 5, 2026
Performing In Vivo and Ex Vivo Electrical Impedance Myography in Rodents
Published on: June 8, 2022
Electrical impedance myography correlates with standard measures of ALS severity
Seward B Rutkove1, James B Caress, Michael S Cartwright
1Department of Neurology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, TCC-810, Boston, Massachusetts, USA, 02215.
Introduction:
Electrical impedance myography (EIM) can be used to assess amyotrophic lateral sclerosis (ALS) progression. The relationship between EIM values and standard assessment measures, however, is unknown.
Methods:
EIM 50 kHz phase data from 60 subjects who participated in a longitudinal natural history study of ALS were correlated with handheld dynamometry (HHD), the ALS Functional Rating Scale-Revised (ALSFRS-R) score, and motor unit number estimation (MUNE).
Results:
Moderate strength correlations between EIM parameters and HHD were observed for both whole-body and individual upper and lower extremity values. Similarly, moderate strength correlations were observed between EIM and ALSFRS-R upper and lower extremity subscores, but not total ALSFRS-R scores. MUNE correlated significantly with single muscle EIM data but not with whole body or upper or lower extremity values.
Conclusions:
These results support the concept that EIM can serve as a meaningful measure of disease severity in ALS.
