Obstructive Sleep Apnea Syndrome (OSAS) is associated with stroke as a risk factor but little is known about the consequences of OSAS on the outcome and the survival after stroke. The aim of the investigators study is first to evaluate the outcome and the survival of patients with stroke depending of OSAS (presence and severity of OSAS) and second to compare the outcome and survival of patients with severe OSAS depending on the treatment of the syndrome with nocturnal continuous positive airway pressure. The investigators hypothesis is that OSAS is associated with worst survival and outcome and needs to be treated at the subacute phase of stroke.

Objective : The aim of our study is to evaluate the consequences of obstructive sleep apnea syndrome on the functional outcome and the survival after an ischemic stroke and to measure the impact of the treatment with continuous positive airway pressure on the outcome of patients with severe obstructive sleep apnea syndrome.Patients and methods : We will prospectively explore by polysomnography, 300 consecutive patients hospitalized for an ischemic stroke in the stroke units of university hospitals at the sub acute phase after stroke (J15±4). 1) We will compare the functional outcome, the neurological impairment, the peripheral endothelial function, the continuous blood pressure measure on 24 hours recording, the quality of life and the survival at 3, 6 and 12 months in four groups of patients depending on their apnea/hypopnea index 2) In patients with severe obstructive sleep apnea syndrome, we will explore the impact on the functional outcome, the neurological impairment, and the survival at 3, 6 et 12 months of a treatment with continuous positive airway pressure (CPAP) randomly compared to a treatment with sham CPAP (non efficacious pressure) during 3 months. Conclusion : This study should allow us to evaluate the consequences of obstructive sleep apnea syndrome on the outcome and the survival after ischemic stroke and the impact and the tolerance of the treatment with continuous positive airway pressure in patients with severe obstructive sleep apnea syndrome.

Inclusion Criteria:

• Brain infarction confirmed by brain imaging

  • follow up possible
  • Severity at admission and at one week follow up:

• NIHSS ≥ 4 or- isolated aphasia (item 9 ofNIHSS ≥ 1) or

• negligence (item 11 du NIHSS ≥ 2) or

• distal motor deficit (score ≥ 1)

  • Health insurance affiliation
  • Inform and free consent agreement