Hyperperfusion syndrome after stenting for intracranial vertebral stenosis

Hyperperfusion syndrome is a rare but well-described complication after endarterectomy or stenting in the carotid circulation. A 66-year-old man who had vertebrobasilar insufficiency refractory to medical treatment because of an intracranial right side vertebral stenosis was referred to our institution for endovascular treatment. Stenting was performed, and after 24 hours, he became extremely agitated, and this was followed by a period of apathy without focal neurological deficits. MRI showed bilateral thalamic hemorrhage. To our knowledge, this is the first report of hyperperfusion syndrome with hemorrhagic presentation after intracranial vertebral artery stenting.