Electrical Impedance Myography as an Outcome Measure in Amyotrophic Lateral Sclerosis Clinical Trials

Study Overview
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Brief Summary
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Trials evaluating new therapies for stopping or slowing the progression of ALS depend critically upon the use of outcome measures to assess whether a potential treatment is effective. The more effective an outcome measure, the fewer patients need to be enrolled and the shorter the trial. Many outcome measures have been used over the years, including strength assessments, breathing tests, functional status surveys, and nerve testing, but all are far from ideal. A new method, called electrical impedance myography (EIM) appears to be especially promising in that it provides very consistent data from one testing session to the next, is sensitive to the muscle deterioration that occurs in ALS, and is entirely painless and non-invasive. In this study, investigators from multiple institutions plan to compare several different outcome measures, including EIM, in approximately 120 ALS patients, with each patient being followed for a period of one year. All of these measures will be compared to one another and an assessment of their ability to detect disease progression made. Our goal will be to determine whether EIM can serve as a valuable new outcome measure, ultimately leading to substantially faster, more effective ALS trials requiring fewer patients.

Official Title
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Electrical Impedance Myography as an Outcome Measure in ALS Clinical Trials

Conditions
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Amyotrophic Lateral Sclerosis

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Definite or probably ALS by El Escorial criteria Muscle strength of at 3.5 in one limb Exclusion Criteria: Forced vital capacity of less than 70% Atypical forms of motor neuron disease (monomelic amyotrophy, primary lateral sclerosis) Pacemaker

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| ALS patients<br>Patients with clinically established amyotrophic lateral sclerosis | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Electrical Impedance Myography | The main outcome measure was the coefficient of variation (CoV) in the rate of the decline for each measure over time. The CoV was calculated by dividing the standard deviation in the rate of decline across the group of subjects and dividing that by the mean rate of decline for the cohort. This approach was taken for each of the measures being evaluated (ALS Functional Rating Scale-Revised, Handheld dynamometry, Electrical impedance myography). The lower the CoV in the rate of decline, the more sensitive it is to identifying a potential treatment effect, since it suggests gives a measure of homogeneity of the rate of decline across the population as well as the overall rate of decline. The smaller the standard deviation across the group and the larger the mean rate of decline across the group, the lower the CoV and the fewer number of subjects needed for a potential clinical trial using that outcome measure. | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| ALS Functional Rating Scale | The main outcome measure was the coefficient of variation (CoV) in the rate of the decline for each measure over time. The CoV was calculated by dividing the standard deviation in the rate of decline across the group of subjects and dividing that by the mean rate of decline for the cohort. This approach was taken for each of the measures being evaluated (ALS Functional Rating Scale-Revised, Handheld dynamometry, Electrical impedance myography). The lower the CoV in the rate of decline, the more sensitive it is to identifying a potential treatment effect, since it suggests gives a measure of homogeneity of the rate of decline across the population as well as the overall rate of decline. The smaller the standard deviation across the group and the larger the mean rate of decline across the group, the lower the CoV and the fewer number of subjects needed for a potential clinical trial using that outcome measure. | 6 months | 
| Handheld Dynamometry | The main outcome measure was the coefficient of variation (CoV) in the rate of the decline for each measure over time. The CoV was calculated by dividing the standard deviation in the rate of decline across the group of subjects and dividing that by the mean rate of decline for the cohort. This approach was taken for each of the measures being evaluated (ALS Functional Rating Scale-Revised, Handheld dynamometry, Electrical impedance myography). The lower the CoV in the rate of decline, the more sensitive it is to identifying a potential treatment effect, since it suggests gives a measure of homogeneity of the rate of decline across the population as well as the overall rate of decline. The smaller the standard deviation across the group and the larger the mean rate of decline across the group, the lower the CoV and the fewer number of subjects needed for a potential clinical trial using that outcome measure. | 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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amyotrophic lateral sclerosis, motor neuron disease, outcome measure, biomarker, impedance