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Updated: Apr 1, 2026
Acquisition and Semi-Automated Analysis of Respiratory Muscle Surface Electromyography
Published on: January 24, 2025
Correlation of single-breath count test and neck flexor muscle strength with spirometry in myasthenia gravis
Bakri Elsheikh1, W David Arnold2,3,4, Shahram Gharibshahi5
1Neurology, Johns Hopkins Aramco Healthcare, Saudi Aramco, P.O. Box 2614, Dhahran, Saudi Arabia, 31311.
Introduction:
Although formal spirometry is the gold standard for monitoring respiratory function in patients with myasthenia gravis (MG), such testing is often delayed or unavailable. There is a need for a simple bedside test that can accurately measure respiratory function.
Methods:
We conducted a prospective, cross-sectional, single-blind study in adults with acetylcholine receptor antibody positive MG. Participants performed the single breath count test (SBCT) and underwent manual muscle strength testing, and a respiratory therapist performed spirometry blinded to SBCT and strength results.
Results:
Thirty-one patients, aged 57 ± 19 years participated. SBCT showed significant correlations with forced vital capacity (FVC), negative inspiratory force, and neck flexor strength (P < 0.01). FVC showed significant correlation with neck flexor strength (P = 0.02) but no correlation with shoulder abductor strength.
Conclusions:
These data suggest that the SBCT and neck flexor strength testing are valuable tools for bedside assessment of respiratory function in MG patients.
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