Prevalence and clinical importance of sleep apnea in the first night after cerebral infarction

Objective: To determine the prevalence of sleep apnea (SA) during the first night after hemispheric ischemic stroke and its influence on clinical presentation, course, and functional outcome at 6 months. Methods: The first night after cerebral infarction onset, 50 patients underwent polysomnography (PSG) followed by oximetry during the next 24 hours. Neurologic severity and early worsening were assessed by the Scandinavian Stroke Scale and outcome by the Barthel Index. Patients were evaluated on admission, on the third day, at discharge, and at 1, 3, and 6 months. Results: There were 30 males and 20 females with a mean age of 66.8 +/- 9.5 years. Latency between stroke onset and PSG was 11.6 +/- 5.3 hours. Thirty-one (62%) subjects had SA (apnea-hypopnea index [AHI] greater than or equal to 10). Of these, 23 (46%) had an AHI greater than or equal to 20 and 21 (42%) an AHI greater than or equal to 25. Sleep-related stroke onset occurred in 24 (48%) patients and was predicted only by an AHI greater than or equal to 25 on logistic regression analysis. SA was related to early neurologic worsening and oxyhemoglobin desaturations but not to sleep history before stroke onset, infarct topography and size, neurologic severity, or functional outcome. Early neurologic worsening was found in 15 (30%) patients, and logistic regression analysis identified SA and serum glucose as its independent predictors. Conclusions: SA is frequent during the first night after cerebral infarction (62%) and is associated with early neurologic worsening but not with functional outcome at 6 months. Cerebral infarction onset during sleep is associated with the presence of moderate to severe SA (AHI greater than or equal to 25).