BACKGROUND: Giant cell arteritis (GCA) of the vertebral artery (VA) is a rare but serious cause of ischemic stroke, however, the long-term clinical and sonographic course of GCA patients with VA involvement (VA+) is poorly understood. METHODS: All patients with suspected GCA who were consecutively referred to our ultrasound (US) lab over a 12-year-period were analyzed. US examination (GCA-specific) of the cranial and cervical arteries was performed. Patients with a positive US diagnosis of GCA were identified, and further analysis was restricted to VA+ patients. Follow-up data were extracted from our hospital database. RESULTS: Among the 785 patients screened for GCA, 220 showed typical US-based findings for GCA, 74 (34 %) of whom were VA+. Fourteen VA+ patients (19 %) had vertebrobasilar ischemia at presentation (11 stroke, 3 TIA). Cerebral ischemia was more frequent in patients with severe compared to moderate VA occlusive disease (35 % vs 9 %
p = 0.0099, OR = 5.39, 95 % CI 1.50-9.42). Two patients died from severe initial stroke. Follow-up data were available for 34 VA+ patients (46 % of all VA+ patients
median period, 740 days), where 13 (38 %) displayed stable US alterations to the VA, 14 (41 %) a regression and 7 (21 %) a progression of stenosis. Four patients (12 %) had vertebrobasilar re-stroke, 3 of them within 30days of treatment initiation. CONCLUSION: One-third-of patients with cranial GCA were VA+, 19 % of whom had vertebrobasilar stroke, of which most had severe VA occlusive disease. Significant rates of stenosis progression and recurrent stroke therefore call for early intensive immunosuppressive treatment.