Cognitive Evoked Potentials in Obstructive Sleep Apnea Syndrome

Introduction

Obstructive sleep apnea syndrome (OSAS) affects approximately 2–14% of adults. This disease is more often seen in middle-aged overweight/obese males, but it is important to remark that it may also affect younger people (3% of all children), women, and thin individuals. OSAS is a risk factor for hypertension and type 2 diabetes.

Abstract

Cognitive functions may be altered in patients with obstructive sleep apnea syndrome (OSAS), and it has been proposed that vigilance and attention changes play a fundamental role in all aspects of cognitive deficits noted in this disease. Event-related potentials (ERPs) are a high-time-resolution technique that can be used to explore the presence of cognitive dysfunction. We review 21 empirical articles on ERPs in OSAS in order to contribute to clarify the pattern of cognitive deficits that are specific to this disease and to see whether there might be an improvement of abnormal psychophysiological findings with continuous positive airway pressure (CPAP) treatment. We conclude that ERP studies have contributed toward demonstrating changes in cognitive attentive processing in OSAS, mainly in association with altered functioning of the prefrontal cortex, and that CPAP treatment may improve vigilance and attention and, more generally, cerebral information processing in these patients. However, deficits remaining during a sufficient CPAP-therapy may reflect irreversible hypoxic cerebral damage.

Keywords

attention, cognitive deficit, continuous positive airway pressure treatment, event-related potentials, information processing, obstructive sleep apnea syndrome