Laboratory of pathology of cerebral circulation

Head of the Laboratory - Doctor of Biological Science, Prof. Semeniutin Vladimir Borisovich

The Laboratory of Pathology of Cerebral Circulation (LPCC) was organized in 1971 on the initiative of Director of the Institute, Honored Science Worker of the Russian Federation, Prof. Ugriumov V.M. In 1972-1982 it was headed by Doctor of Medical Science, Prof. Teplov S.I., who was a physiologist. Together with Prof. Ugriumov V.M. he outlined both fundamental and applied prospective trends of research in pathophysiology of cerebral circulation and formulated a hypothesis concerning the role of the hypothalamo-hypophyseal system in mechanisms of cerebral circulation disorders in patients with different neurosurgical pathology.

A valuable contribution was made into development of the following problems:

- blood supply and metabolism in cerebral circulatory hypoxia;
- neurogenic regulation of cerebral blood flow and the role of neurogenic and hormonal factors in pathogenesis of vascular disorders;
- interrelations between cerebral and systemic hemodynamics;
- changes of blood circulation and respiration in cerebrovascular pathology;
- common adaptation responses in cerebrovascular disorders.

Results of experimental and clinical-physiologic investigations carried out during this period served a basis for 2 monographs, theses for a degree of a Doctor (2) and Candidate (7) of Medical Science. In 1985-1987 the Laboratory was headed by Candidate of Medical Science, Senior Researcher Zubkov Yu.N. The main goals of clinical-physiologic research were studying disorders of cerebral circulation in various neurosurgical pathology (CNS trauma, neurovascular diseases, tumors). Study of mechanisms of circulatory disturbances in nerves of patients with trauma of the peripheral nervous system was begun in 1987.

Today great attention is paid to improvement of conventional methods and development of new modalities for estimation of cerebral circulation. The following devices have been designed: universal electrodes for local measurements of physiologic indices, an apparatus for measuring impedance of the brain, a thermoflowmeter which allows to estimate cerebral temperature and blood flow velocity, a three-channel commutator for polarographic and electrophysiologic investigations.

The LPCC has been headed by Doctor of Biological Science, Senior Researcher Semeniutin V.B. since 1987. By the present moment the employees of the Laboratory have developed new methods of studying the system of cerebral circulation. Among them one can mention a method of estimating exclusion of arteriovenous malformation from circulation in intravascular interventions, a device for measuring cerebral blood flow velocity, a method of measuring intracranial pressure and mechanic resistance of the brain, a method of estimating autoregulation of cerebral blood flow in neurosurgical patients, a method of intraoperative determination of borderlines of a crush focus in patients with craniocerebral trauma.

Results of investigations carried out by the Laboratory employees or with their active participation have been summarized in theses for a degree of a Doctor (4) and Candidate (4) of Medical Science.

Transcranial Doppler has been used since 1992. It allows to estimate a state of major cerebral vessels and an effect of various antispasmodics when linear blood flow velocity in spamodic cerebral arteries of patients in an acute period of rupture of intracranial aneurysm is monitored.

Results of investigations were presented at Euromed-93, Euromed-95, Euromed-96 Leipzig Fairs and won a high appraisal of specialists. New prospective methods in the field of pathophysiology of cerebral circulation are being developed in cooperation with German colleagues led by Mihel I., DM and a physiologist from the Institute of Medical Informatics of Charite Clinic of Humboldt Berlin University. In particular, it concerns comparison of changes of cerebral hemodynamics and cardiac activity in standardized psychic load.

Results of research carried out in the LPCC are used in scientific-practical work and in the process of teaching at the Russian Medicomilitary Academy, Saint Petersburg Academy of Postgraduate Education, at the Institute of Medical Informatics of Charite Clinic of Humboldt Berlin University, other research and educational establishments.

Prospects of further investigation of disorders of cerebral circulation in various categories of neurosurgical patients have been determined. The main purpose of research is studying compensatory and reserve potential of the system of cerebral circulation and mechanisms of its regulation.

. The following trends are being developed:

- search of informative indices of active responses of the brain to standardized functional tests;
- studying a state of autoregulation of cerebral blood flow at early stages of cerebral circulation disorders in patients with different neurosurgical pathology;
- estimation of a pharmacologic effect on tension of cerebral arteries in patients with ruptured intracranial aneurysms;
- estimation of transcranial Doppler potential in investigation of cerebral hemodynamics and a functional state of cerebral vessels;
- development of a system of intraoperative contact dopplerographic (20 MHz) monitoring carried out in patients with intracranial aneurysms and arteriovenous malformations;
- development of a system of intraoperative monitoring carried out in occluding lesions of extracranial segment of internal carotid arteries, endovascular operations on aneurysms and arteriovenous malformations;
- development of means of estimating radicality of exclusion of arteriovenous malformations from circulation;
- studying reserve of collateral circulation and autoregulation of cerebral blood flow in temporary clipping of cerebral arteries and guided arterial hypotension with the help of contact 20 MHz Doppler and hydrogen clearance in open intracranial operations on aneurysms.