title: Effect of acute intermittent hypoxia on motor function in individuals with chronic spinal cord injury following ibuprofen pretreatment: A pilot study.
abstract: Acute intermittent hypoxia (AIH) enhances lower extremity motor function in humans with chronic incomplete spinal cord injury (SCI). AIH-induced spinal plasticity is inhibited by systemic inflammation in animal models. Since SCI is frequently associated with systemic inflammation in humans, we tested the hypothesis that pretreatment with the anti-inflammatory agent ibuprofen enhances the effects of AIH.
  
  
  
  A randomized, double-blinded, placebo-controlled crossover design was used. Nine adults (mean age 51.1 ± 13.1 years) with chronic motor-incomplete SCI (7.7 ± 6.3 years post-injury) received a single dose of ibuprofen (800 mg) or placebo, 90 minutes prior to AIH. For AIH, 9% O2for 90 seconds was interspersed with 21% O2for 60 seconds. Maximal voluntary ankle plantar flexion isometric torque was assessed prior to, and at 0, 30, and 60 minutes post-AIH. Surface electromyography (EMG) of plantar flexor muscles was also recorded.
  
  
  
  Torque increased significantly after AIH at 30 (P = 0.007; by ∼20%) and 60 (P < 0.001; by ∼30%) minutes post-AIH versus baseline. Ibuprofen did not augment the effects of AIH. EMG activity did not increase significantly after AIH; however, there was a significant association between increases in torque and EMG in both gastrocnemius (R2= 0.17, P < 0.005) and soleus (R2= 0.17, P < 0.005) muscles.
  
  
  
  AIH systematically increased lower extremity torque in individuals with chronic incomplete SCI, but there was no significant effect of ibuprofen pretreatment. Our study re-confirms the ability of AIH to enhance leg strength in persons with chronic incomplete SCI.
authors: a Rehabilitation Institute of Chicago, Northwestern University , Chicago , IL , USA.
authors: Meaghan
authors: M
authors: Lynch
authors: b Department of Physical Medicine & Rehabilitation , Northwestern University , Chicago , IL , USA.|c Department of Medical Physics and Biomedical Engineering , University College London , London , UK.
authors: Lynsey
authors: L
authors: Duffell
authors: b Department of Physical Medicine & Rehabilitation , Northwestern University , Chicago , IL , USA.
authors: Milap
authors: M
authors: Sandhu
authors: a Rehabilitation Institute of Chicago, Northwestern University , Chicago , IL , USA.
authors: Sudarshan
authors: S
authors: Srivatsan
authors: a Rehabilitation Institute of Chicago, Northwestern University , Chicago , IL , USA.
authors: Kelly
authors: K
authors: Deatsch
authors: a Rehabilitation Institute of Chicago, Northwestern University , Chicago , IL , USA.
authors: Allison
authors: A
authors: Kessler
authors: d Department of Physical Therapy and McKnight Brain Institute , University of Florida , Gainesville , FL , USA.
authors: Gordon S
authors: GS
authors: Mitchell
authors: b Department of Physical Medicine & Rehabilitation , Northwestern University , Chicago , IL , USA.|e Max Nader Center for Rehabilitation Technologies & Outcomes , Rehabilitation Institute of Chicago , Chicago , IL , USA.|f Department of Medical Social Sciences , Northwestern University , Chicago , IL , USA.|g Department of Physical Therapy and Human Movement Sciences , Northwestern University , Chicago , IL , USA.
authors: Arun
authors: A
authors: Jayaraman
authors: h Sensory Motor Performance Program , Rehabilitation Institute of Chicago, Professor, Northwestern University , Chicago , IL , USA.
authors: William Zev
authors: WZ
authors: Rymer
mesh_terms: D000328:Adult; D000368:Aged; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007052:Ibuprofen / Q000008:administration & dosage / Q000627:therapeutic use*; D007537:Isometric Contraction; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000008:administration & dosage* / Q000627:therapeutic use; D010102:Oxygen Inhalation Therapy / Q000009:adverse effects / Q000379:methods*; D010865:Pilot Projects; D013119:Spinal Cord Injuries / Q000188:drug therapy / Q000628:therapy*
chemical_list: D018712:Analgesics, Non-Narcotic; D010100:Oxygen; D007052:Ibuprofen
keywords: Humans; Hypoxia; Ibuprofen; Muscle strength dynamometer; Neuronal plasticity; Rehabilitation; Spinal cord injury