Neural injury in sleep apnea.
Sleepiness has long been recognized as a presenting symptom in obstructive sleep apnea syndrome, but persistent neurocognitive injury from sleep apnea has been appreciated only recently. Although therapy for sleep apnea markedly improves daytime symptoms, cognitive impairments may persist despite long-term therapy with continuous positive airway pressure. We know now that certain groups of neurons, typically those that are more metabolically active, are more vulnerable to injury than others. Animal models of sleep apnea oxygenation patterns have been instrumental in elucidating mechanisms of injury. The hypoxia/reoxygenation events result in oxidative, inflammatory, and endoplasmic reticulum stress responses in susceptible neural groups. With molecular pathways being fleshed out in animal models, it is time to carefully and systematically examine neural injury in humans and test the applicability of findings from animal models. To succeed, however, we cannot view sleep apnea as an isolated process. Rather, injury in sleep apnea is more likely the consequence of overlapping injuries from comorbid conditions. The progress in elucidating mechanisms of neural injury is palpable, and it now seems we indeed are closer to developing therapies to prevent and treat neural injury in obstructive sleep apnea.
Lim
Diane C
DC
Center for Sleep and Neurobiology, University of Pennsylvania School of Medicine, Translational Research Building, Room 2115, 125 South 31st Street, Philadelphia, PA, 19104, USA.
Veasey
Sigrid C
SC
D000818:Animals; D001930:Brain Injuries / Q000473:pathology*; D003072:Cognition Disorders / Q000209:etiology; D004195:Disease Models, Animal; D006801:Humans; D009431:Neural Conduction / Q000502:physiology; D012891:Sleep Apnea Syndromes / Q000150:complications*; D020196:Trauma, Nervous System / Q000209:etiology*