Sleep-Disordered Breathing in Chronic SCI

Investigators will examine the effect of PAP therapy and sleep apnea on thinking (especially memory, learning and concentration), sleep quality, and risks for future heart (cardiovascular) problems in persons with chronic spinal cord injury (SCI). SDB is a condition where there are pauses in breathing or shallow breathing during sleep due to airway narrowing. This leads to low oxygen levels during sleep and sleep disruption. The usual treatment for sleep apnea is PAP (Positive Airway Pressure) worn while sleeping. This involves the use of usually a mask connected to a machine that supplies enough pressure to keep the airway open during sleep. SDB will be diagnosed in SCI participants using unattended portable level II polysomnography (PSG) (a portable at home sleep study for one night). Sleep quality (SQ), SDB risk, insomnia severity, daytime sleepiness,and mood will be measured using questionnaires. Cognitive evaluations will be completed prior to randomization on all participants who also complete a portable PSG to evaluate general and pre-morbid function, immediate verbal memory, simple and sustained attention, processing speed, and executive function. Blood and urine samples will be taken for participants with SDB diagnosis after randomization. All randomized subjects will be fitted with a nasal or full-face mask and head gear. PAP will be delivered by an auto-titrating device. These devices automatically set the level of delivered pressure to ensure upper airway patency, to treat detected apneas, and hypopneas. All subjects will be instructed to use the device nightly during sleep, for the ensuing four months. All outcome measurements will be reassessed after four months of PAP.