Objective:

Test the feasibility and reliability of at-home Electrical Impedance Myography (EIM) measurements collected via the Myolex mScan® device in individuals with amyotrophic lateral sclerosis (ALS), and to assess its potential as a biomarker of disease progression.

Background:

Identifying sensitive tools to assess new ALS therapies remains a major challenge due to the disease's heterogeneous presentation. Current standardized instruments, such as the ALS Functional Rating Scale-Revised (ALSFRS-R), are limited by subjectivity and may lack sensitivity to detect subtle changes. As an alternative, EIM is a technology that assesses muscle physiology in a non-invasive and painless way, providing a quantitative measurement for tracking disease progression.

Design/Methods:

This ongoing prospective cohort study enrolls ALS participants across six U.S. centers. The Myolex mScan® is a novel portable EIM device that enables at-home assessments, thereby increasing data collection frequency and reducing participant burden. Over eight months, EIM parameters for six muscle groups are assessed using the mScan device twice-weekly by a study partner. At-home ALSFRS-R scores are also performed weekly. Participants attend three clinic visits for handheld dynamometry, EIM, and ALSFRS-R assessments. Changes in EIM parameters and their relationship with functional measures over time are being analyzed.

Results:

Data from five participants using the device for over two months show that at-home EIM phase values at 447kHz for selected muscles in upper and lower extremities shows a declining trend. When compared with the at-home ALSFRS-R data, both EIM parameters and  questionnaire scores have been decreasing over time. Although, additional data is needed to further evaluate the relationship between these measures.

Conclusions:

Preliminary analyses of at-home EIM show that the technology is both feasible and sensitive to ALS-associated declines in muscle health. With continued data collection, we will be able to determine EIM's value as a sensitive and meaningful biomarker of ALS progression for at-home use in therapeutic clinical trials.