Dissections of the cervical arteries account for approximately 15-20 % of all strokes in young patients. Clinically they present with laterocervical and/or hemicranial pain associated to a Horner syndrome in case of carotid dissection and a posterior cervical pain associated to headache in the occipital area in case of vertebral dissection. A multifactorial origin is often suggested, resulting from the combination of a weakness of the arterial wall, hereditary or not, of environmental factors such minor trauma or a previous infection and also of the presence of a certain number of vascular risk factors such as high blood pressure or migraines. The diagnosis is best established with MRI which shows specifically the intramural hematoma. Treatment includes anticoagulants or antiplatelets agents.