Attentional deficits in patients with obstructive sleep apnea syndrome: An event-related potential study

Objective: Patients with obstructive sleep apnea syndrome (OSAS) show cognitive deficits, vigilance alteration and attentional decline. The aim of this study was to use event-related potentials (ERP) to further document the attentional impairments in these patients. Methods: Twelve OSAS patients and 12 age-matched controls underwent the ERP task which consisted in the presentation of short (50 ms, 50%) and long tones (400 ms, 50%). For these two categories, 90% were standard (1000 Hz) and 10% were deviant tones (750 or 1250 Hz). Subjects had to discriminate short and long tones by a motor response. Results: OSAS patients had a sustained and delayed P300 in comparison with control subjects following standard tones (p < 0.05). A reduction in amplitude was found in OSAS patients for the P3a obtained by the subtraction of standard from deviant tones (p < 0.05). No group difference was observed for NI, mismatch negativity and reorienting negativity components. Conclusions: Apneas and hypopneas produce deficits related to involuntary attentional switch and stimulus classification processing. Significance: The changes observed in P3a and P300 components further support the hypothesis that attentional deficits play a pivotal role in cognitive deficits noted in OSAS. (c) 2006 Published by Elsevier Ireland Ltd on behalf of International Federation of Clinical Neurophysiology.