no need to include more patients for analysis. 40 patients initially (36 actual)

The management of patients with ischemic stroke or transient ischemic attack is based on the preservation of a brain area by maintaining sufficient intracranial hemodynamics (IH) and with rapid recanalization.

The impact of the patient's position (supine or seated position) on the IH in the event of narrowing or occlusion of an artery is poorly assessed but may be of particular importance. Variations in blood flow according to the positioning of the patient's body are measurable using a transcranial Doppler.

The main objective is to verify whether intracerebral hemodynamic changes during early verticalization after ischemic stroke or transient ischemic attack are more frequent in patients with carotid stenosis or occlusion compared to those without stenosis or occlusion.

Inclusion Criteria:

• Ischemic stroke (AIC) or transient ischemic attack (AIT) of the carotid artery

• Duration of symptoms less than 48 hours

• Absence of homolateral or downstream intracranial stenosis or occlusion M1

• Lifting authorized by the referent clinician.

• Rankin's score before AIC/AIT ≤ 2

  • For cases:

• Carotid stenosis of more than 50% NASCET (North American Symptomatic Carotid Endarterectomy Trial) or an occlusion

  • For controls:

• Absence of carotid stenosis greater than 50% NASCET (North American Symptomatic Carotid Endarterectomy Trial) or occlusion

Exclusion Criteria:

- Disrupted vigilance

Secondary exclusion criteria:

• Absence of a homolateral temporal acoustic window at the lesion
• Impossibility to verticalize the patient

Participants will be recruited during their hospitalization in the USINV for the management of ischemic stroke.