[Carotid dysplasias].

Fibro-muscular dysplasia is the principal dysplasia of the internal carotid artery (ICA). It mainly affects women and is usually diagnosed at about the age of 50. The best known lesions are segmental medial defects. They are often associated with other local (aneurysm) or general (mainly renal) malformations. Congenital factors probably play a very important part in its genesis. Ischemic cerebrovascular accidents (transient or permanent), or cerebral haemorrhage are the usual modes of presentation. The diagnosis may be suspected on ultrasonic examination but can only be confirmed by arteriography. Therapy is not standardised as the natural history has not been definitely established. Megadolicho-carotid artery, hypoplasia and other dysplasias of the ICA are briefly described and illustrated.