Acute ischemic stroke and sleep apnea: evolution of clinical findings, diffusion-weighted MRI, and blood pressure in the first 3 days after stroke onset

Background and Objectives: Sleep apnea (SA) is present in about 50% of patients (pts) with acute ischemic stroke. Hypoxia and hemodynamic changes accompany SA. The aim of the study is to test the hypothesis that in the acute phase of stroke moderate-severe SA leads to an enlargement of the ischemic volume that is more pronounced than in pts without SA. Design/methods: We include pts with neuroradiologically proven ischemic stroke and admission within 24 hours after stroke onset. Stroke severity is estimated by NIH and Scandinavian stroke scale (NIHSS, SSS) at admission (day 1) and day 3. Sleep breathing is assessed by an intelligent CPAP device (Autoset® Embletta pds, ResMed) the first night after admission. Moderate-severe SA (MSSA) is defined by an apnea-hypopnea-index (AHI)>/=25. Blood pressure (BP) monitoring is performed at intervals of 30 minutes with an ambulatory device (bp one, Cardiette) from 8 p.m. of day 1 until 6 a.m. of day 3. Nighttime BP dipping is defined by a ratio of nighttime/daytime mean systolic BP values of 20%) of stroke volume. In 11 pts SA was mild or absent. One of these pts had a clinical stroke progression and 7 of them had a clear-cut increase of stroke volume. Mean values of systolic and diastolic blood pressure were higher in pts with MSSA, this difference was, however, not statistically significant. A nighttime BP dipping was absent in 5 of 7 pts with MSSA, and in 10 of 11 pts with mild or no SA. Conclusions: Preliminary results of this ongoing project show no significant difference in the MRI stroke progression between pts with MSSA and with mild or no SA. Conversely, the results suggest that MSSA may favor clinical stroke progression in pts with acute ischemic stroke. This detrimental effect may, however, not be related to blood pressure changes or to the presence of a non-dipping status.