study has implications for a better understanding of theneurofunctional underpinnings of OSA and the effects ofPAP treatment on brain function.Support: Research supported by the Ittleson Foundation.

doi:10.1016/j.sleep.2006.07.092

189An epidemiologic perspectiveTerry Young *

University of Wisconsin at Madison, Department of

Preventive Medicine, USA

doi:10.1016/j.sleep.2006.07.093

190 Blood pressure control and hypertension

Thomas G. Pickering *

Columbia Presbyterian Medical Center, Behavioral Car-

diovascular Health and Hypertension Program, New

York, NY, USA

doi:10.1016/j.sleep.2006.07.094

191Arrhythmias and sudden cardiac death

Virend K. Somers *

Mayo Clinic College of Medicine, Division of Cardiovas-

cular Disease, Rochester, MN, USA

doi:10.1016/j.sleep.2006.07.095

192 Cerebrovascular disease and stroke

Devin L. Brown *

A. Alfred Taubman Health Center, Neurology Depart-

ment, Ann Arbor, MI, USA

Obstructive sleep apnea (OSA) is quite prevalent inthe post stroke population affecting over 50% of thosewith acute ischemic stroke. OSA has recently emergedas an independent risk factor for ischemic stroke. Thereasons for this relationship are unclear, but may berelated to OSA’s effect on coagulation, cerebral hemody-namics, and oxidative stress. Furthermore, OSA hasbeen associated with traditional vascular risk factorsincluding hypertension, diabetes, and atrial fibrillation.Continuous positive airway pressure (CPAP) mayreduce the risk of stroke in those with OSA, but nodefinitive study has been performed. Some studies haveshown that CPAP reduces blood pressure, and may alsoreduce insulin resistance and the risk of recurrent atrial

fibrillation among those with OSA who underwent car-dioversion. Additionally, one small observational seriessuggested that tolerance to CPAP after an initial ische-mic stroke is associated with a lower risk of a recurrentvascular event.

In addition to being a risk factor for stroke, OSA andOSA severity are associated with poorer outcomes afterstroke, including functional outcome and mortality.These findings have led investigators to test CPAP forstroke patients with OSA. Preliminary studies suggestthat acceptance of CPAP may be a particular challengefor stroke patients. Non-acceptance may be even morecommon in those with aphasia and lower functional sta-tus. Unfortunately, no large randomized, placebo-con-trolled studies have yet been performed assessing theeffect of CPAP on stroke outcome; although, there havebeen a few small randomized studies performed withouta placebo control. Some have shown no benefit to CPAP,while others suggest a benefit in depression or sense ofwellbeing post stroke. More research is needed in thisimportant area to determine the effects of CPAP treat-ment on stroke risk and recovery, optimal timing of ther-apy initiation, and optimal titration schemes in the poststroke period.

doi:10.1016/j.sleep.2006.07.096

193 The failing heart

Paola Lanfranchi *

Hopital du Sacre-Coeur, Centre de Recherche, Montreal,

Que., Canada

doi:10.1016/j.sleep.2006.07.097

194 Ambulatory monitoring in the diagnosis of sleep

apnea – pro

Neil Douglas *

University of Edinburgh, Royal Infirmary, Respiratory

Medicine, United Kingdom

doi:10.1016/j.sleep.2006.07.098

196 Ambulatory monitoring in the diagnosis of sleep

apnea – conNancy Collop

Johns Hopkins University, Division of Pulmonary/Critical

Care Medicine, Baltimore, MD, USA

doi:10.1016/j.sleep.2006.07.099

S38 Abstracts / Sleep Medicine 7 (2006) S1–S127