Effects of continuous positive airway pressure treatment on cognitive functions in patients with severe obstructive sleep apnoea.

INTRODUCTION

Obstructive sleep apnoea syndrome (OSAS) has numerous implications for health and can affect neurocognitive functions in patients.

OBJECTIVE

To evaluate the neuropsychological functions most affected by OSAS, the factors associated with OSAS severity that are related to those functional limitations, and the effect of therapy with continuous positive airway pressure.

PATIENTS AND METHOD: The sample consisted of 60 participants: 30 patients diagnosed with OSAS (clinical group) and 30 people without the disorder (control group). Memory, intellectual processes, and attention were analysed with selected subtests from the Luria-Nebraska neuropsychological battery (immediate memory, logical memory, intellectual processes, and attentional control subtests).

RESULTS

Patients obtained significantly lower scores than controls in most of the areas evaluated. Associations were identified between subjective sleep quality and conceptual activity (r=-0.279; P<.05) and attentional control (r=-0.392; P<.01); between oxygen saturation and both immediate memory (r=0.296; P<.05) and thematic drawings (r=0.318; P<.05); and between apnoea-hypopnoea index and immediate memory (r=-0.303; P<.05), logical memory (r=-0.359; P<.01), and thematic drawings (r=-0.302; P<.05). Continuous positive airway pressure was shown to be effective (P=.03) only for improving immediate memory in patients with OSAS.

CONCLUSIONS

Patients with severe OSAS showed memory and attentional limitations, associated with poorer quality of sleep and with worst AHI and SaO2 mean. The CPAP use improved memory of the patients evaluated.