title: Correlation of single-breath count test and neck flexor muscle strength with spirometry in myasthenia gravis.
abstract: BACKGROUND
  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.
authors.affiliation: Neurology, Johns Hopkins Aramco Healthcare, Saudi Aramco, P.O. Box 2614, Dhahran, Saudi Arabia, 31311.
authors.forename: Bakri
authors.initials: B
authors.lastname: Elsheikh
authors.affiliation: Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.|Department of Physical Medicine and Rehabilitation, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.|Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.
authors.forename: W David
authors.initials: WD
authors.lastname: Arnold
authors.affiliation: Neurology, Kaiser Permanente Neurology, Panorama City, California, USA.
authors.forename: Shahram
authors.initials: S
authors.lastname: Gharibshahi
authors.affiliation: Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.
authors.forename: Jerold
authors.initials: J
authors.lastname: Reynolds
authors.affiliation: Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.
authors.forename: Miriam
authors.initials: M
authors.lastname: Freimer
authors.affiliation: Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.|Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.
authors.forename: John T
authors.initials: JT
authors.lastname: Kissel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D009157:Myasthenia Gravis / Q000175:diagnosis* / Q000503:physiopathology*; D009334:Neck Muscles / Q000503:physiopathology*; D012129:Respiratory Function Tests; D012132:Respiratory Muscles / Q000503:physiopathology*; D016037:Single-Blind Method; D013147:Spirometry; D013223:Statistics as Topic; D014797:Vital Capacity / Q000502:physiology; D055815:Young Adult
keywords: forced vital capacity; myasthenia gravis; neck flexor strength; negative inspiratory force; single breath count; spirometry