A longitudinal study identifies progressive alterations in brain white matter microstructure and networks in male adults with obstructive sleep apnea and their recovery after sleep surgery (P2-13.005)

Abstract

<h3>Objective:</h3> We aimed to investigate the effects of surgical treatment on the white matter (WM) microstructure and connectivity. <h3>Background:</h3> Obstructive sleep apnea (OSA) is an increasingly prevalent clinical problem resulting in significant effects on quality of life and cognitive impairments. Surgical treatment is an effective treatment for those unable to use positive airway pressure (PAP), but the therapeutic effect of upper airway surgery on the brain has yet to be determined. <h3>Design/Methods:</h3> Twenty-one male patients with moderate to severe OSA were recruited for multi-level sleep surgery. Overnight polysomnography (PSG), neuropsychiatric tests and brain MRI scans were acquired before surgery and at least 6 months after surgery. Nineteen male patients with untreated OSA were also included as a reference group and with follow-up for 1 year or longer. We calculated the interscan changes of DTI parameters including fractional anisotropy ( FA) in the treated and untreated groups. We also assessed changes in network/connectivity properties based on graph theory. <h3>Results:</h3> Surgically treated patients showed improvement in daytime sleepiness, PSG parameters and verbal memory score after surgery. Globally FA was significantly in the surgical group compared to the untreated group; the untreated group showed disease progression (negative FA) whereas the treated group displayed no progression (near-zero FA). Especially, FA of the tracts involved in the limbic system was higher after surgery. In the analysis of network property metrics, between ness of the right cuneus and frontal pole was significantly higher and clustering coefficient of bilateral post central area was lower in the surgical group compared to the untreated group. <h3>Conclusions:</h3> Surgical treatment of OSA can prevent progressive alterations in WM microstructural integrity and disruptions in local network integration and segregation. The positive effects of surgery were prominent for the tracts involved in the limbic system, which may further explain the cognitive improvement observed after the treatment of OSA. <b>Disclosure:</b> Hea Ree Park has nothing to disclose. Dr. Chai has nothing to disclose. Dr. Joo has nothing to disclose. Prof. Kim has nothing to disclose.