Cerebral hyperperfusion syndrome (CHS) is a dangerous complication following carotid artery revascularization. Without prompt treatment, CHS can lead to fatal intracranial hemorrhage. One of the most important symptoms of CHS is an ipsilateral headache, often in the orbital region, of a migraine-like nature. Numerous risk factors for the development of CHS after carotid endarterectomy and carotid artery stenting have been identified. Wide variations in the incidence of CHS across patient samples (0.4–31.3%) are related to difficulties in diagnosing CHS, as headache is a marker not only for CHS but also for cardiovascular disease, as well as to the existence of related syndromes (LPS, HE, PRES, RCVS). Six pathophysiological mechanisms contributing to the development of CHS have been proposed.

The hypothesis of a link between CHS and cerebral arteriovenous imbalance is highly promising for a detailed study. In the pathogenesis and diagnosis of CHS, a significant role is played by:

1) the general condition of the patient's venous system (the magnitude of his venous pressure) before revascularization of the internal carotid artery;

2) the characteristics of significant stenosis in the internal carotid artery (the presence of an auscultatory "silent" plaque or a plaque with an increase in peak blood flow velocity);

3) characteristics of blood flow in the internal jugular vein (the value of the time-averaged mean blood flow velocity in the internal jugular vein [VTAmeanIJV]) before and after carotid artery revascularization;

4) a modified (simplified) index of venous-arterial ratio – the unilateral intrajugular-intracarotid index of venous-arterial balance (IUL-IJV/ICA) before and after carotid artery revascularization.

Correction of venous-arterial balance parameters after internal carotid artery revascularization can prevent the development of CHS. The future development of standardized protocols and consideration of influencing factors can improve the accuracy of extracerebral blood flow measurements.

Ekaterina Emets works in the Voronezh Regional Clinical Hospital No. 1 as a functional diagnostic. From 2020, she has been a part-time postgraduate student of the Bakoulev National Medical Research Center for Cardiovascular Surgery (Ministry of Health of Russia). She is the co-author of 3 review articles published in the central Russian journal “Clinical Physiology of Circulation”.