Gray Matter Deficits Found in Sleep Apnea Patients

May be cause of cognitive impairment in OSA; appears reversible with CPAP

WEDNESDAY, Nov. 17 (HealthDay News) -- Cognitive impairment in patients with obstructive sleep apnea (OSA) appears to be linked to a decrease of gray-matter volume in specific regions of the brain; however, these may be partially or fully reversed with early detection and treatment, according to a study published online Oct. 29 in the American Journal of Respiratory and Critical Care Medicine.

Nicola Canessa, Ph.D., of Vita-Salute San Raffaele University in Milan, Italy, and colleagues evaluated 17 treatment-naive sleep apnea patients and 15 age-matched healthy controls to assess cognitive deficits and corresponding brain morphology changes in OSA as well as the modifications after treatment with continuous positive airway pressure (CPAP).

The investigators found significant decreases in gray-matter volume in patients with OSA compared to those without the condition. The investigators also found that specific brain functions were more strongly impacted than others, including executive function and abstract reasoning. In addition, patients with OSA showed impairments in memory and attention, and experienced increased daytime sleepiness. However, after three months of treatment with CPAP, patients with OSA demonstrated gains in cerebral regions associated with executive function and showed significant cognitive improvement in all domains.

"In summary, this study provides the first evidence that structural brain abnormalities exist in regions susceptible to hypoxemia, and that they can change with treatment. These results suggest that even the negative neurological effects of hypoxemia may reverse with consistent and thorough treatment. Therefore, adherence to treatment can lead not only to clinical, but also to brain-structural recovery," the authors write.

The study was supported by the Respironics Foundation.

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