Immediate and Long-term Neurocognitive Outcome in Patients with Obstructive Sleep Apnea Syndrome After Continuous Positive Airway Pressure Treatment

Neurocognitive dysfunction is a major clinical consequence in patients with obstructive sleep apnea syndrome (OSAS). The effects of continuous positive airway pressure (CPAP) treatment, as the gold standard of treatment in OSAS, on this major complication are controversial. The duration and compliance of CPAP are thought to be important factors but evidence is lacking. This study is designed to evaluate the effects of immediate (one night), long-term (3 months) influence and the compliances of CPAP treatment on the neurocognitive function in OSAS patients. We enrolled newly diagnosed severe OSAS patients. Neurocognitive function test battery, CANTAB (Cambridge Neuropsychological Test Automated Battery), was performed before, one night and 3 months of CPAP treatment. Patients with CPAP compliance rate ≥ 70 % and < 50 % were grouped into good and poor adherence subjects, respectively. Fourteen patients were enrolled in final analyses. Six of them were in poor compliant group. Improvements in attention domain were found in all subjects after one-night treatment and maintained till three-month follow-up. Additional improvements in some attention performances and visual memory performances were gained only after three-month treatment. Significant changes of decision-making and response control function were found between good and poor compliance groups after three-month treatment. CPAP can improve some neurocognitive function at the very first day used. Longer treatment of CPAP can additionally improve some other neurocognitive functions. Compliance of CPAP has influence on the recovery of neurocognitive functions in patients with severe OSAS.