This project is focused on the treatment of obstructive sleep apnea in the acute phase of stroke. Stroke is a frequent pathology with a high morbidity and mortality rate. Although it has now been proved that obstructive sleep apnea syndrome (OSAS) is a risk factor of stroke, on the other hand, there is evidence that 50 to 70% of patients in the acute phase of stroke have obstructive sleep apnea (OSA) based on an apnea-hypopnea index (AHI) of ≥ 10. OSA is associated with worse functional outcomes and higher mortality in the post-stroke period. Profound hemodynamic fluctuations and hypoxia generated by sleep apnea are likely to aggravate cerebral ischemia, particularly in the acute phase of stroke in the potentially reversible ischemic penumbra. Continuous Positive Airway Pressure (CPAP) is the primary treatment for obstructive sleep apnea.

Yet, to our knowledge, there have been very few studies aimed at demonstrating the value of CPAP in the treatment of obstructive sleep apnea in the acute phase of stroke. Only one randomised trial has provided the means to document neurological improvement at mid term (1 month) in a targeted population.

Before undertaking a comparative study evaluating the efficacy of CPAP in the acute phase of ischemic stroke, it is worth evaluating the feasibility and tolerance of introducing CPAP at the very early stage of ischemic stroke. Therefore, the purpose of our study is to evaluate the feasibility of CPAP in the treatment of OSA in the acute phase of ischemic stroke.

Inclusion Criteria:

• - Clinical presentation of ischemic stroke confirmed by imaging (CT or MRI brain scan)
• less than 24 hours from onset of symptoms
• admitted to the Neurovascular unit of the Emergency Hospitalisation Department of 'Hôpital Nord' of the university hospital of Saint-Étienne
• presenting obstructive sleep apnea syndrome (defined as an apnea-hypopnea index (AHI) of ≥ 10 and > 50% of obstructive events)
• written consent of patient

Exclusion Criteria:

• Concussion (Coma Glasgow Score <12)
• Comprehension aphasia
• Uncontrollable confusion and agitation
• History of dementia
• History of ischemic stroke with neurological damage
• History of hemorrhagic stroke
• History of epilepsy
• Cerebrospinal fluid leak, recent cranial surgery or head injury
• Serious bullous lung disease
• Hypoxic pulmonary disease
• Pleurisy or pneumothorax requiring draining
• Respiratory distress requiring mechanical ventilation
• Oxygen therapy prior to stroke
• Non-invasive ventilation therapy prior to stroke
• Hypotension
• Dehydration
• Hypersalivation
• Vomiting
• Pregnancy, parturients, breast feeding
• Absence of consent