Related Experiment Video
Updated: Jun 8, 2025
Non-invasive Assessment of Changes in Corticomotoneuronal Transmission in Humans
Published on: May 24, 2017
McArdle sign and neck flexion-induced change in central motor conduction in multiple sclerosis
E Matthew Hoffman1, Lucille Brown2, Evan Jolliffe3
1Department of Neurology, Mayo Clinic, Rochester, MN, USA.
Background:
Rapidly reversible weakness with neck flexion (McArdle sign) is common in patients with multiple sclerosis (MS). The pathophysiology is unknown.
Objective:
To evaluate changes in central motor conduction time (CMCT) in patients with and without McArdle sign.
Methods:
We measured McArdle sign with a torque cell and CMCT with neck flexed and extended in patients with MS, other causes of myelopathy, and healthy controls.
Results:
CMCT was prolonged with neck flexion disproportionately in those with MS-associated myelopathy (MSAM) with prominent McArdle sign compared to MS patients with lesser degrees of McArdle sign, and to controls.
Conclusion:
McArdle sign may result from stretch-induced slowing of conduction due to demyelination.
More Related Videos
08:16Utility of Dissociated Intrinsic Hand Muscle Atrophy in the Diagnosis of Amyotrophic Lateral Sclerosis
Published on: March 4, 2014
06:35In Vivo Electrophysiological Measurement of Compound Muscle Action Potential from the Forelimbs in Mouse Models of Motor Neuron Degeneration
Published on: June 15, 2018
