P300 abnormalities in patients with severe sleep apnea syndrome

We investigated the mechanism of abnormal P300 findings in the patients wit h severe sleep apnea syndrome (SAS). Compared with controls, SAS patients s howed significantly longer Latency of P300, Not the mean sleep latency in m ultiple sleep latency test but the percentage of total periods in which per centage desaturation time fell below 90% to total sleep time correlated wit h P300 latency in the patients. During nasal CPAP treatment, P300 latency w as significantly shortened in the patients under 45 years, while the elderl y patients did not show statistical change, We speculated that P300 latenci es might be prolonged due to nocturnal hypoxia with SAS and the abnormality might be irreversible, especially in elderly patients.