Fibromuscular dysplasia and the brain. I. Observations on angiographic, clinical and genetic characteristics.

The angiographic, clinical, and genetic characteristics of fibromuscular dysplasia (FMD) are reviewed in 37 patients (mean age 48 years) selected from a pool of 4000 angiograms of carotid or vertebral arteries. FMD was a neglected pathogenic factor in 28 patients with hemorrhagic or ischemic cerebral lesions. The aneurysms found in 19 patients had conventional appearance and were mainly located in the internal carotid or middle cerebral arteries and on the same side as the most affected cervical artery, which suggests that aneurysms and FMD are pathogenically related. A clinical syndrome is presented where headache, ECG-abnormalities, hypertension, mental distress, tinnitus, vertigo, arrhythmia, TIA, and syncope are frequent components. Hemicrania, sometimes combined with ipsilateral Horner's Syndrome, was found in patients with advanced lesions in the carotid artery of the same side. An associated occurrence of stroke in pedigrees, especially among young and middle aged females, indicates that FMD in the majority of cases in inherited as an autosomal dominant trait with reduced penetrance in males.