Spontaneous arteriovenous fistulas of cerebral vessels in association with fibromuscular dysplasia.

Four cases of spontaneous arteriovenous fistula seen in association with fibromuscular dysplasia of the parent artery are presented. In two patients, the fistula was between the carotid artery and cavernous sinus; in two others, the fistula involved the vertebral artery and paravertebral veins. It is postulated that the angiopathy was responsible for the fistula. Treatment by detachable balloon embolization was successful in each case; however, the presence of the fibromuscular dysplasia made treatment more difficult.