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Quantitation of McArdle's Sign and Evaluation of Specificity for Multiple Sclerosis

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03122873
Recruitment Status : Completed
First Posted : April 21, 2017
Last Update Posted : August 30, 2017
Information provided by (Responsible Party):
Brian G. Weinshenker, M.D., Mayo Clinic

Brief Summary:
The study is designed to quantitate McArdle's sign, an increase in measurable weakness with neck flexion described in patients with multiple sclerosis, and to determine whether it is or is not specific for multiple sclerosis.

Condition or disease
Multiple Sclerosis

Detailed Description:

Finger strength will be measure using a torque-measuring device designed to quantitate finger extension strength. The device was designed for point of treatment use, patient safety and portability. Strength will be measured in 5 paired trials, first with neck extended and then with neck flexed. Two protocols will be evaluated, one testing isometric strength against a fixed resistance and the second testing strength against dynamic resistance. McArdle's sign is the difference between strength with neck extension and strength with neck flexion.

The data will be digitally registered and dynamic neck position will be recorded electronically in real time. Graphs of dynamic changes in torque versus neck position will be generated and superimposed. Strength will be quantitated using Matlab software.

Consecutive patients with myelopathy of any cause with detectable finger extensor weakness will be studied, either due to MS or due to other cause of myelopathy (other inflammatory, vascular, compressive, neoplastic and other). Additionally, normal controls will be studied as will patients with finger extension weakness due to peripheral nerve lesions.

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Study Type : Observational
Actual Enrollment : 125 participants
Observational Model: Case-Control
Time Perspective: Prospective
Official Title: Quantitation of McArdle's Sign and Evaluation of Specificity for Multiple Sclerosis
Actual Study Start Date : February 1, 2016
Actual Primary Completion Date : June 30, 2017
Actual Study Completion Date : June 30, 2017

Resource links provided by the National Library of Medicine

Myelopathy of any cause
Male or female 18 years or older with myelopathy and detectable finger extension weakness due to 1) prototypic multiple sclerosis (N=50) 2) other etiologies of myelopathy (N=50), including other inflammatory conditions (e.g. idiopathic transverse myelitis, neuromyelitis optica, acute disseminated encephalomyelitis, sarcoidosis) or other etiologies (compression, vascular disorders, degenerative disorders, neoplasms).
Peripheral neuropathy
Male or female 18 years or older with C7 radiculopathy, radial neuropathy, plexopathy, peripheral neuropathy, who have detectable finger extension weakness.
Healthy Controls
Male and female 18 year or older with no finger extension weakness and no known neurological conditions.

Primary Outcome Measures :
  1. Difference in quantitative measure of strength between extended positions of the neck and fully flexed position of the neck (McArdle's sign) [ Time Frame: through study completion, an average of 1 year ]
    Comparison of means and medians of the difference in strength in the fully extended and fully flexed positions ("McArdle's sign") measured using a torque measurement device between multiple sclerosis versus other myelopathy and between multiple sclerosis and normal controls; measurements are done in 5 successive trials of extension and flexion and the mean percentage difference between extension and flexion of the last 4 trials is averaged to calculated the McArdle's sign; the goal is to determine whether there is a specific level of McArdle sign that is diagnostic for MS using receiver operator curve method.

Secondary Outcome Measures :
  1. Relative sensitivity of clinical versus instrument-based detection of McArdle's sign. [ Time Frame: through study completion, an average of 1 year ]
    Compare the clinical detection of the sign by the referring clinician and technician compared to the device-determined McArdle's sign

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Patients with myelopathy of any cause and peripheral neuropathy who have detectable finger extension weakness.

Inclusion Criteria:

  • Myelopathy of any cause with finger extension weakness
  • Patients with peripheral neuropathy with finger extension weakness
  • Healthy controls

Exclusion Criteria:

  • Pregnant subjects.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03122873

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United States, Minnesota
Mayo Clinic
Rochester, Minnesota, United States, 55905
Sponsors and Collaborators
Mayo Clinic
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Principal Investigator: Brian Weinshenker, MD Mayo Clinic

Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Brian G. Weinshenker, M.D., PI, Mayo Clinic Identifier: NCT03122873     History of Changes
Other Study ID Numbers: 15-009122
First Posted: April 21, 2017    Key Record Dates
Last Update Posted: August 30, 2017
Last Verified: August 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

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Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
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Multiple Sclerosis
Pathologic Processes
Demyelinating Autoimmune Diseases, CNS
Autoimmune Diseases of the Nervous System
Nervous System Diseases
Demyelinating Diseases
Autoimmune Diseases
Immune System Diseases