Global cognitive profile and different components of reaction times in obstructive sleep apnea syndrome: effects of continuous positive airway pressure over time

Obstructive sleep apnea syndrome (OSAS) has been recurrently associated with cognitive and psychomotor impairments. However, the occurrence and possible reversibility of these deficits are still extremely controversial, also as a result of different methodologies adopted used by scholars. The aim of the present study was to compare over time the global cognitive profile of patients with OSAS undergoing the continuous positive airway pressure treatment (CPAP; N = 23) with that of patients with OSAS who were not (N = 10). A group of healthy participants (N = 30) was also included. This study adopted a specific methodological approach allowing the researchers to distinguish between the cognitive and the motor component of reaction times (RTs). After baseline assessment, the same tests were administered after three and six months. No significant differences emerged between groups at each time point. On the other hand, the analysis of cognitive score trajectory over time revealed differences between groups. While healthy controls and OSAS patients undergoing CPAP showed increased MoCA test scores after three months, patients not undergoing CPAP improved their scores only after six months. In addition, patients treated with CPAP also showed significantly faster psychomotor response in motor RTs over time. Results seem to conceivably support a global cognitive vulnerability of non-treated OSAS patients. Conversely, the RT response of treated patients can be increased over time by CPAP, at least in the motor component of RTs. Therefore, our study suggests that CPAP may play an important role by slowing down the negative effects of OSAS, and by fostering sufficient cognitive functioning and adequate psychomotor speed.