The Comparison of Clinical Findings and Treatment Between Unilateral and Bilateral Vertebral Artery Dissection

Background: There are limited clinical studies of bilateral vertebral artery dissection (VAD). Objective: To compare the characteristics, imaging findings, and treatments between patients with bilateral and unilateral VAD. Methods: Between February 2007 and May 2017, 31 (mean age: 53.0 years; 23 men, 8 women) out of 171 VAD patients were hospitalized because of bilateral VAD. Onset type, dissection site, dominant side of the VA, imaging features, treatments, and outcomes were investigated based on medical records. The dominant side of the VA was determined by basi-parallel anatomical scanning. Results: Twenty (64.5%) of 31 patients exhibited bilateral VAD on both sides of V4. The dominant side of the VA was right in 16 patients and left in 15 patients. The pearl and string sign (an angiographical finding with both dilatation and stenosis) was frequently observed on the dominant VAD side, while a tapered occlusion and string sign were most common on the nondominant side. For clinical subtype of VAD, 6 (19.4%) patients had subarachnoid hemorrhage, 10 (32.3%) ischemic stroke, 3 (9.7%) infarction plus subarachnoid hemorrhage, and 12 (38.7%) only headache. The frequency of infarction was increased in bilateral VAD compared with unilateral (P < .05). Surgical intervention was performed in 3 cases, while 14 patients received endovascular intervention. Conclusions: Infarction occurred frequently in bilateral VAD patients, and 17 patients required an intervention (mainly endovascular) for VA. The treatment strategy varied depending on the clinical subtype, imaging findings of VAD, and morphology of the dominant VAD side.