Obstructive sleep apnea is highly prevalent but easily undiagnosed and is an independent risk factor for cognitive impairment.
However, it remains unclear how OSA is linked to cognitive impairment. In the present study, the authors found the correlation between morphological changes of perivascular spaces and cognitive impairment in OSA patients. Moreover, the authors developed a novel set of dynamic contrast-enhanced magnetic resonance imaging methods to evaluate the fluid dynamics of glymphatic drainage system.
The scientists here found that the inflow and outflow parameters of the glymphatic drainage system in patients with OSA were obviously changed, indicating impairment of glymphatic drainage due to excessive perfusion accompanied with deficient drainage in OSA patients. Moreover, parameters of the outflow were associated with the degree of cognitive impairment, as well as the hypoxia level. In addition, continuous positive airway pressure enhances performance of the glymphatic drainage system after 1 month treatment in OSA patients.
The scientists here proposed that ventilation improvement might be a new strategy to ameliorate the impaired drainage of glymphatic drainage system due to OSA-induced chronic intermittent hypoxia, and consequently improved the cognitive decline.
