Clinical trial NCT03122873: Quantitation of McArdle's Sign and Evaluation of Specificity for Multiple Sclerosis
Official title: Quantitation of McArdle's Sign and Evaluation of Specificity for Multiple Sclerosis
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Multiple Sclerosis
Lead sponsor: Mayo Clinic
Sponsor class: OTHER
First posted: 2017-04-21
Enrollment: 125
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients with myelopathy of any cause and peripheral neuropathy who have detectable finger extension weakness.

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.

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.

Eligibility criteria: Inclusion Criteria:

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

Exclusion Criteria:

* Pregnant subjects.

Primary outcomes:
measure: Difference in quantitative measure of strength between extended positions of the neck and fully flexed position of the neck (McArdle's sign)
timeFrame: through study completion, an average of 1 year
Secondary outcomes:
measure: Relative sensitivity of clinical versus instrument-based detection of McArdle's sign.
timeFrame: through study completion, an average of 1 year
Other outcomes:
Locations:
city: Rochester
country: United States
facility: Mayo Clinic
state: Minnesota
Study officials:
affiliation: Mayo Clinic
name: Brian Weinshenker, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Savoldi F, Nasr Z, Hu W, Schilaty ND, Delgado AM, Mandrekar J, Kaufman KR, Berglund L, Weinshenker BG. McArdle Sign: A Specific Sign of Multiple Sclerosis. Mayo Clin Proc. 2019 Aug;94(8):1427-1435. doi: 10.1016/j.mayocp.2019.01.047. Epub 2019 Jul 11.