Mild to Moderate Sleep Apnea Is Linked to Hypoxia-induced Motor Recovery after Spinal Cord Injury

The study investigates the link between sleep-disordered breathing (SDB) and motor recovery induced by acute intermittent hypoxia (AIH) in individuals with chronic incomplete spinal cord injury (SCI). The researchers analyzed data from 20 participants who had baseline sleep assessments and participated in one of three clinical trials with similar experimental designs involving AIH or sham treatment. The study found that participants with mild to moderate sleep apnea demonstrated greater motor gains with AIH therapy compared to those without apnea, suggesting that SDB may precondition individuals to respond more positively to AIH therapy.

• 1
  Mild to moderate sleep apnea (5 , apnea–hypopnea index ,30/h) occurred in 50% of study participants.
• 2
  Participants with mild to moderate SDB demonstrated greater motor gains with AIH therapy (Cohen’s d median: 3.6; range: 20.5 to 13.6) versus those without apnea (1.7; range: 26.6 to 4.9; P = 0.043).
• 3
  The oxygen desaturation index (ODI-4%) was an independent predictor of Cohen’s d (P = 0.007), suggesting that the AIH response mostly related to repetitive nocturnal O2 desaturations.