Dataset Information

Reducing sample size requirements for future ALS clinical trials with a dedicated electrical impedance myography system.

ABSTRACT:

Objective

In this longitudinal multicenter cohort study, we evaluated the potential of a dedicated electrical impedance myography (EIM) device to assess ALS progression and the system's basic reproducibility and diagnostic accuracy.

Methods

Forty-six ALS patients underwent up to five sequential measurements of multiple muscles over a period of 8 months at 2-month intervals using the mView EIM device (Myolex, Inc., San Francisco, CA). Standard measures of disease status were also obtained. A group of 30 healthy volunteers and 30 ALS-mimics were evaluated once to determine if the technique could assist with initial diagnosis. Several electrode arrays and EIM outcomes were assessed.

Results

EIM tracked ALS progression; power analyses suggested a 5.2-fold reduction in sample size requirements compared to ALSFRS-R by utilizing 50 kHz phase value from the muscle with the greatest EIM decline in each subject. This progression rate correlated to total ALSFRS-R progression, with R = 0.371, p = 0.021. Reproducibility was high, with both intra- and inter-rater intraclass correlation coefficients for individual muscles mostly greater than 0.90. The mean 50 kHz phase distinguished between ALS patients and healthy controls (area-under-curve 0.78, 95% confidence intervals (CIs) 0.68, 0.89), but not between mimics and ALS patients (area-under-curve 0.60, 95% CIs 0.47, 0.73).

Conclusions

While limited in its specificity to identify ALS versus disease mimics, these results support the hypothesis that single-muscle EIM can serve as a convenient, repeatable, and powerful outcome measure in ALS clinical trials.

SUBMITTER: Shefner JM

PROVIDER: S-EPMC6438779 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature

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Publications

Reducing sample size requirements for future ALS clinical trials with a dedicated electrical impedance myography system.

Shefner Jeremy M JM Rutkove Seward B SB Caress James B JB Benatar Michael M David William S WS Cartwright Michael S MS Macklin Eric A EA Bohorquez Jose L JL

Amyotrophic lateral sclerosis & frontotemporal degeneration 20180928 7-8

<h4>Objective</h4>In this longitudinal multicenter cohort study, we evaluated the potential of a dedicated electrical impedance myography (EIM) device to assess ALS progression and the system's basic reproducibility and diagnostic accuracy.<h4>Methods</h4>Forty-six ALS patients underwent up to five sequential measurements of multiple muscles over a period of 8 months at 2-month intervals using the mView EIM device (Myolex, Inc., San Francisco, CA). Standard measures of disease status were also o ...[more]

PMID: 30265154

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Project description:Background: Electrical impedance myography (EIM) is a non-invasive method that provides information about muscle health and changes that occur within it. EIM is based on the analysis of three impedance variables: resistance, reactance, and the phase angle. This systematic review of the literature provides a deeper insight into the scope and range of applications of EIM in health and physical exercise. The main goal of this work was to systematically review the studies on the applications of EIM in health and physical exercise in order to summarize the current knowledge on this method and outline future perspectives in this growing area, including a proposal for a research agenda. Furthermore, some basic assessment principles are provided. Methods: Systematic literature searches on PubMed, Scopus, SPORTDiscus and Web of Science up to September 2020 were conducted on any empirical investigations using localized bioimpedance devices to perform EIM within health and physical exercise contexts. The search included healthy individuals, elite soccer players with skeletal muscle injury, and subjects with primary sarcopenia. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist was used to develop the systematic review protocol. The quality and risk of bias of the studies included were assessed with the AQUA tool. Results: Nineteen eligible original articles were included in this review, which were separated into three tables according to the nature of the study. The first table includes six studies on the bioelectrical characterization of muscle. The second table includes five studies analyzing muscle changes in injured elite soccer players. The third table includes studies on the short-, medium-, and long-term bioelectrical adaptations to physical exercise. Conclusions: EIM has been used for the evaluation of the muscle condition in the clinical field over the last few years, especially in different neuromuscular diseases. It can also play an important role in other contexts as an alternative to complex and expensive methods such as magnetic resonance imaging. However, further research is needed. The main step in establishing EIM as a valid tool in the scientific field is to standardize the protocol for performing impedance assessments.

Dataset Information

Reducing sample size requirements for future ALS clinical trials with a dedicated electrical impedance myography system.

Objective

Methods

Results

Conclusions

Publications

Reducing sample size requirements for future ALS clinical trials with a dedicated electrical impedance myography system.

Similar Datasets

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