An adult case of idiopathic internal carotid-internal jugular vein arteriovenous fistula.

Carotid-jugular fistula is an abnormal connection between the carotid artery and/or its branches and jugular vein. It can develop either because of trauma or spontaneous causes. Traumatic fistula may occur after head injuries and can range from minor falls to severe penetrating wounds. Traumatic fistula may also result from endovascular therapy; however, these fistulas may be congenital arteriovenous connections that open spontaneously in the setting of collagen vascular disease, atherosclerotic disease, hypertension, or childbirth. Spontaneous fistulas between internal carotid artery and internal jugular vein are very exceptional diseases; therefore, this case is presented for its rare incidence in literature.