In acute ischemic stroke, the identification of an etiology is of major importance to prevent recurrence by providing the best treatment. Because of numerous possible underlying etiologies, the etiological work-up of ischemic stroke includes a wide range of diagnostic tests, which can be invasive, long and expensive. Moreover, many patients receive a diagnosis of undetermined stroke even after all available diagnosis tests are done, precluding optimal treatment.

Asymptomatic MES detected by transcranial doppler have been reported in patient with ischemic stroke. It has been previously demonstrated that MES predict stroke recurrence and that the frequency of MES depends on stroke etiology. However, the pattern of MES has never been correlated to stroke etiology. Transcranial-holter is a novel ambulatory system which allows prolonged recording (up to 4 hours) leading to an increased detection of MES.

Therefore, transcranial holter with an 4 hour-recording will be performed for consecutive eligible patients hospitalized in our stroke care unit. During the recording, the patient will be able to continue their usual activities (eating, walking, speaking and sleeping).

All the included patients will have a classical follow-up at 3, 6 months and 12 months. The neurologist, blinded to the results of transcranial-holter, will have to prescribe and analyze the results of diagnostic tests to identify stroke etiology. Stroke etiology will be established according to the ASCOD classification. Questioning and neurological exam (NIHSS score) will be performed looking for potential recurrent stroke.

Inclusion Criteria:

• Ischemic stroke in the middle cerebral artery territory
• Acute ischemic stroke within the 7 first days from the onset of the symptoms
• Patient hospitalized in our stroke care unit
• Man or woman older than 18 years
• Patient affiliated to a social security system
• Free Consent, informed writing signed by the participant or the person of confidence and the investigator (no later than the day of inclusion and before any examination required by research)

Exclusion Criteria:

• Transient ischemic stroke
• Ischemic stroke in the vertebro-basilar or anterior cerebral artery territory.
• Proximal middle cerebral artery occlusion leading to the impossibility of recording
• Patient who could not express his consent
• Patient under guardianship or judicial protection
• Pregnant or breastfeeding woman
• Emergency situation
• Life expectancy under 6 months

Exclusion criteria (after inclusion) :

• Absent of bilateral Acoustic window
• Analyzable Recording <30min