[Hyperperfusion syndrome]

Hyperperfusion syndrome (HPS) is a neurological syndrome, which consists of a triad of unilateral headache, seizures and focal neurological deficits. In its extreme form it can present as an intracerebral hemorrhage. Originally HPS was described in patients undergoing carotid endarterectomies for severe carotid stenosis but, more recently, it was also described following other means of cerebral revascularization such as stent-assisted angioplasty. It is believed to result from hyperperfusion of blood into an unprotected or damaged brain parenchyma. HPS is considered to be a rare complication of carotid endarterectomy, yet this may not be precise as the full picture of the syndrome usually develops after several days, following the patient's discharge from hospital. Physicians who are unfamiliar with this syndrome are called to treat these patients and thus it may be misdiagnosed. For invasive vascular procedures the hospitalization time is even shorter and therefore, this scenario may become more common. Nowadays, HPS may be diagnosed fairly easily, even before its typical clinical presentation has developed, with the use of transcranial doppler intra- or postoperatively. Meticulous blood pressure monitoring can prevent its appearance in most cases.