[Horner's syndrome revealing a spontaneous carotid artery dissection].

We report a case of spontaneous carotid artery dissection suspected by the appearance of Horner's syndrome. Under medical treatment, the intramural hematoma resolved within 3 months. The patient had an uneventful recovery, without any residual neurologic deficit. Spontaneous arterial dissection is responsible for a hematoma in the arterial wall without significant trauma. The pathogenesis remains unknown. Predisposing factors seem to exist. The clinical presentation is variable mainly due to local compression of adjacent structures which can precede a transient or permanent neurological deficit. The diagnosis is confirmed by Doppler US, CT angiography or magnetic resonance angiography, the best optional investigations. The treatment mainly consists of stroke prevention by anticoagulation versus antiplatelet therapy. The role of surgery and/or endovascular techniques has not yet been confirmed.