Pathogenetic links between cognitive impairment in arterial hypertension and anatomical and functional characteristics of hippocampal morphology and blood supply (a literature review)

Aim. To update the study on morphological changes in the hippocampal structure and blood supply in conditions of persistent arterial hypertension with a focus on the cognitive sphere state. Materials and methods. The authors independently searched and selected scientific literature for a systematic review in the PubMed, Scopus, and Cochrane databases using the following keywords “arterial hypertension”, “cognitive functions”, “morphological and functional state of the hippocampus” in full-text articles in English and Ukrainian based on the study results with a level of evidence I–III. Results. The authors have conducted a systematic review of articles and scientific publications in PubMed, Scopus and Cochrane databases. The information of the hippocampal structure, blood supply, functions and importance for the generation of human cognitive performance in health and in conditions of persistent arterial hypertension has been processed. Conclusions. The current research results allow asserting that the hippocampus plays an important role in combining environmental signals and creating an integral and unified perception in the spatial and temporal domains. The performance efficiency depends on cellular signaling and stability, adequate blood supply, neurotransmitter balance, and the character of a receptor landscape. Experimental studies and clinical observations show cerebral arteriole reconstruction and constriction as well as decreased NO bioavailability in the hippocampus induced by chronic arterial hypertension to compensate for excessive pressure and increased blood flow pulsatility and to protect microvessels from damage. Increased vasoconstriction results in hypoperfusion and neuronal damage, which is most obvious in the hippocampal CA1 and CA3 areas and visualized as a reduced number of chaotically scattered cells with cytoplasmic vacuoles, nuclear pyknosis and nucleolysis.