Sleep Apnea: Mechanism and Cerebrovascular Consequences

This study will determine the effect of ventilatory stimulation on obstructive sleep apnea in selected patients with stroke. We will select a subset of patients with stroke in the prior 3 months who are most likely to have ventilatory instability as a cause of the upper airway obstruction as indicated by the absence of obesity, an abnormal hypocapnic apnea threshold and resolution of obstructive apnea during CO2 administration. Following baseline polysomnography, patients will be randomly assigned to acetazolamide (250 mg hs [at bedtime]) versus placebo for 7 days. Polysomnography will be repeated and then subjects will cross-over therapies for another 7 days followed by a final nocturnal polysomnography.

This study never enrolled patients. It was a component of a larger VA Merit grant and the other aims of the grant were completed but due to logistic issues and recruitment challenges this particular protocol was never made active.

Inclusion Criteria: We will select non-obese patients (body mass index [BMI] <30 kg/m2) with stroke diagnosed during the 3 previous months and obstructive sleep apnea on screening sleep study (apnea-hypopnea index [AHI] >15 events/hr of study time). Patients with stroke will be selected based on the following criteria: 85 years old or less with a history of ischemic stroke within 3 months resulting in mild to moderate neurological impairment (Rankin scale < 3) Exclusion Criteria: Hemorrhagic stroke, A history of chronic obstructive lung disease, Left ventricular ejection fraction (LVEF) <55% Evidence of nasal or pharyngeal obstruction on physical examination.