Гемодинамические показатели в покое у пациентов с мягким сдавлением гиппокампа

Contemporary neural network models of brain functioning assume the self-organization of distributed neuronal elements into networks supporting information processing. Functional connectivity between distant brain regions in the absence of external stimulation is maintained by resting-state networks, in which the hippocampus is involved to varying degrees. Of key importance is the interaction of the hippocampus with the prefrontal cortex, which is responsible for cognitive control and executive functions. The present study included 32 patients with benign extra-axial brain tumors exerting mild compression on the mediobasal regions of the temporal lobe in the hippocampal area (17 with left-sided and 15 with right-sided localization), as well as 19 healthy control participants. The patient groups were comparable in terms of tumor morphometric characteristics, degree of hemispheric compression, and socio-demographic variables. Functional near-infrared spectroscopy (fNIRS) was used to assess cerebral hemodynamic activity. Brain activity was recorded from the prefrontal cortex during three-minute resting-state sessions preceded by different instructional conditions. A significant reduction in interhemispheric connectivity was observed in the clinical groups. Differences between patients with left- and right-sided tumors became more pronounced under guided resting-state conditions involving instructions for free, internally oriented thought. Patients with left-sided tumors demonstrated a predominance of activity in the left prefrontal cortex, whereas patients with right-sided tumors exhibited a more symmetrical distribution of activity. The use of guiding instructions made it possible to reveal specific features of functional brain organization in patients with space-occupying brain lesions.