Neurocognitive Recovery Following Continuous Positive Airway Pressure Therapy in Patients with Moderate to Severe Obstructive Sleep Apnea

<b>Background/Objectives</b>: Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder associated with cognitive decline. Evidence regarding the reversibility of these deficits after continuous positive airway pressure (CPAP) therapy remains inconsistent. <b>Methods</b>: This prospective observational study included 60 adults with newly diagnosed moderate-to-severe OSA (median age 51 years; 80% male), who underwent baseline assessment using P300 event-related potentials and the Montreal Cognitive Assessment (MoCA). After three months of CPAP therapy with confirmed good compliance, both measures were re-evaluated. <b>Results</b>: After three months of CPAP therapy, a statistically significant reduction in P300 latency (<i>p</i> < 0.001) and an increase in amplitude were observed, accompanied by significant improvements in executive function (<i>p</i> < 0.001), attention (<i>p</i> < 0.001), and delayed recall (<i>p</i> < 0.001). <b>Conclusions</b>: CPAP therapy leads to measurable recovery of cognitive function in patients with moderate-to-severe OSA, suggesting partial reversibility of neurocognitive impairment associated with sleep-disordered breathing. These findings highlight the importance of early recognition and treatment of OSA to prevent long-term cognitive decline.