title: Functional Magnetic Stimulation of Inspiratory and Expiratory Muscles in Subjects With Tetraplegia.
abstract: Respiratory complications are major causes of morbidity and mortality in persons with a spinal cord injury, partly because of respiratory muscle paralysis. Earlier investigation has demonstrated that functional magnetic stimulation (FMS) can be used as a noninvasive technology for activating expiratory muscles, thus producing useful expiratory functions (simulated cough) in subjects with spinal cord injury.
  
  
  
  To evaluate the effectiveness of FMS for conditioning inspiratory and expiratory muscles in persons with tetraplegia.
  
  
  
  A prospective before and after trial.
  
  
  
  FMS Laboratory, Louis Stokes Cleveland VA Medical Center, Cleveland, OH.
  
  
  
  Six persons with tetraplegia.
  
  
  
  Each subject participated in a 6-week FMS protocol for conditioning the inspiratory and expiratory muscles. A magnetic stimulator was used with the center of a magnetic coil placed at the C7-T1 and T9-T10 spinous processes, respectively. Pulmonary function tests were performed before, during, and after the protocol.
  
  
  
  Respiratory variables included maximal inspiratory pressure (MIP), inspiratory reserve volume (IRV), peak inspiratory flow (PIF), maximal expiratory pressure (MEP), expiratory reserve volume (ERV), and peak expiratory flow (PEF).
  
  
  
  After 6 weeks of conditioning, the main outcome measurements (mean ± standard error) were as follows: MIP, 89.6 ± 7.3 cm H2O; IRV, 1.90 ± 0.34 L; PIF, 302.4 ± 36.3 L/min; MEP, 67.4 ± 11.1 cm H2O; ERV, 0.40 ± 0.06 L; and PEF, 372.4 ± 31.9 L/min. These values corresponded to 117%, 107%, 136%, 109%, 130%, and 124% of pre-FMS conditioning values, respectively. Significant improvements were observed in MIP (P = .022), PIF (P = .0001), and PEF (P = .0006), respectively. When FMS was discontinued for 4 weeks, these values showed decreases from their values at the end of the conditioning protocol, which suggests that continual FMS may be necessary to maintain improved respiratory functions.
  
  
  
  FMS conditioning of the inspiratory and expiratory muscles improved voluntary inspiratory and expiratory functions. FMS may be a noninvasive technology for respiratory muscle training in persons with tetraplegia.
authors.affiliation: Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH; Cleveland Clinic Lerner College of Medicine, Cleveland, OH(∗).
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Cleveland Clinic Lerner College of Medicine, Cleveland, OH(†).
authors.forename: Ela
authors.initials: E
authors.lastname: Plow
authors.affiliation: Dabir Surfaces, Inc, Southfield, MI(‡).
authors.forename: Vinoth
authors.initials: V
authors.lastname: Ranganthan
authors.affiliation: Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH; Cleveland Clinic Lerner College of Medicine, Cleveland, OH(¶).
authors.forename: Honglian
authors.initials: H
authors.lastname: Huang
authors.affiliation: Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH(§).
authors.forename: Melissa
authors.initials: M
authors.lastname: Schmitt
authors.affiliation: Metrohealth Medical Center, Cleveland, OH(∗∗).
authors.forename: Gregory
authors.initials: G
authors.lastname: Nemunaitis
authors.affiliation: Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH(††).
authors.forename: Clay
authors.initials: C
authors.lastname: Kelly
authors.affiliation: Cleveland Clinic Lerner College of Medicine, Cleveland, OH(‡‡).
authors.forename: Frederick
authors.initials: F
authors.lastname: Frost
authors.affiliation: Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH; Cleveland Clinic Lerner College of Medicine, Cleveland, OH(¶¶). Electronic address: linv@ccf.org.
authors.forename: Vernon
authors.initials: V
authors.lastname: Lin
mesh_terms: D006801:Humans; D011446:Prospective Studies; D011782:Quadriplegia; D012132:Respiratory Muscles; D012133:Respiratory Paralysis; D013119:Spinal Cord Injuries