[Healthy person's cerebral reactions to the rhythmic transcranial magnetic stimulation of different intensity].

At 8 healthy examinees-volunteers of 22-25 years the functional effects of super-threshold (above 1.2 T) and subthreshold (70-80% of a motor threshold) rTMS of premotor cortexes medial departments were compared. Functional brain activity changes were estimated (before and 1 hour after stimulation) by comparing data including neuropsychological testing, visual and spectral-coherent EEG-analysis, and also haemodynamic parameters. The number of the work's problem included selection of activating orientated stimulation's frequency, and also specification objective EEG--criteria of efficiency rTMS. It is established the effect of EEG-analysis during different frequency photostimulation for a choice of activating rTMS. The received results reveal EEG-coherence as one of the most informative characteristics of cerebral neuro-dynamics under rTMS-influence. Dependence of stimulation's functional effects (activated or brake character) from initial level of the intercentral coherent communications is noted. It is revealed that rTMS of the healthy examinees causes certain changes of functional activity of a brain, distinct from placebo-effects. rTMS-effect dependent on intensity (super--or sub-threshold), and also from features of an initial intercentral rations. More expressed functional changes are observed in the left hemisphere. It is shown big by reactance of the left hemisphere on this influence. In formation of brain responses on rTMS the active role of the vascular factor is shown.

[Cerebral circulatory autoregulation as a guide for controlling the parameters of assisted ventilation in acute severe brain injury].

The paper presents the results of cerebral circulation (CC) in 17 ventilated patients with severe brain injury in its acute phase. All the patients developed traumatic subarachnoidal hemorrhage, which was accompanied with angiospasm in the majority of cases. Doppler transcranial study (DTCS) was performed, by using the carotid compression test; the findings correlated with paCO2 and CV parameters. A dynamic study was performed every two days starting from their admission to an intensive care unit to the recovery from coma or normalization of CC parameters. The dilation and constriction components of the CC reserve were assessed from the results of this test and continued to be controlled during therapy. Thus, this paper shows the possibility of goal-oriented correction of CC autoregulation and optimization by selecting the parameters of assisted ventilation and by changing paCO2 under the guidance of Doppler transcranial study.

[The orthostatic resistance of the cerebral and peripheral circulations in patients with contusive brain lesions]. / Ortostaticheskaia ustoichivost' mozgovogo i perifericheskogo krovoobrashcheniia u bol'nykh s kontuzionnymi porazheniiami golovnogo mozga.

Orthostatic tests with printing recording of EEG, REG, RVG were used to examine the functional status of the truncal level of circulatory regulation in patients with brain confusions. Within the first 24 hours after brain injury there was a significant reduction in the pulse blood filling of cerebral vessels in the vascularization areas of carotid and vertebral arteries along with higher vascular tone; pulse blood filling of peripheral vessels in the lower extremities remained normal with a marked decrease in their vascular tone. Orthostatic tests showed the asymmetric enhancement of a dilating arterial response in the virtual absence of a constrictive response of lower extremity vessels. Following 2-3 weeks of brain injury, cerebral and peripheral hemodynamics tends to normalize: in orthostasis, the responsive dilatation of cerebral vessels diminished, inter-hemispheric asymmetry levelled; as compared to the normal values, cerebral vasodilation, however, remained enhanced with drastically suppressed peripheral vascular responsiveness. The described impaired vascular responsiveness were more evident in the presence of EEG truncal dysfunction syndromes. The findings suggest that central regulatory disorders of vascular tone play an important role in the pathogenesis of traumatic brain disease. A particular phasic periodicity of vascular responses to orthostatic exposure, which are characteristic of the acute and early rehabilitative periods of moderate brain injury.

[The use of sodium nitroprusside in the anesthesiological support of cerebral angiography]. / Primenenie nitroprussida natriia pri anesteziologicheskom obespechenii tserebral'noi angiografii.

Complex study of the effect of sodium nitroprusside intra-arterial and intravenous infusion under local and general anesthesia on the cerebral, peripheral, and general hemodynamics during cerebral angiography was carried out in 43 patients with neurosurgical pathology (17 females and 26 males from 17 to 58 years of age). The authors proved the efficacy of intraarterial and, to a lesser measure, of intravenous sodium nitroprusside infusion in relieving spasm of the cerebral arteries developing during cerebral angiography.

[Regulation of cerebral circulation in an upright posture of the human trunk]. / K voprosu o reguliatsii mozgovogo krovoobrashcheniia pri vertikal'nom polozhenii tulovitsa cheloveka.

The functional mechanisms responsible for orthostatic tolerance of cerebral circulation in the normal man and in ambulatory and bedridden neurosurgical patients were investigated, using the following methods: cerebral blood flow by means of xenon-133 clearance, measurement of brain perfusion pressure, ventricular pressure, acid-base equilibrium in the blood flowing in and out of the brain, determination of cardiac output and stroke volume, electroencephalography, and rheography of cerebral and peripheral vessels. In the normal men and patients with compensated neurosurgical pathologies, the transfer into the head-up position induced small changes in the systemic and cerebral regional circulation. This was associated with complex reactions of the vascular system triggered by the receptors of the sinocarotid area. The normal response of the vascular system to the orthostatic load involved dilatation of cerebral and constriction of peripheral arteries, tachycardia, increased central venous pressure, moderate decrease of brain perfusion pressure and intraventricular pressure. In vascular pathological reactions constriction of peripheral arteries and veins was disturbed; cardiac output and stroke volume, cerebral blood flow velocity, central venous and intraventricular pressures were decreased.

[Complex experimental and clinical study of the effect of nitroglycerin on the cerebral, peripheral and systemic circulations]. / Kompleksnoe izuchenie v éksperimente i klinike vliianiia nitroglitserina na mozgovoe, perifericheskoe i sistemnoe krovoobrashchenie.

Experiments on anesthetized and unanesthetized cats and examination of 42 neurosurgical patients have shown that nitroglycerin considerably increases cerebral and peripheral circulation, raises the pressure in the internal jugular vein and brain ventricles, increases the lumen of cerebral vessels of predominantly minor caliber, speeds up the linear and volumetric rate of the cerebral blood flow. Nitroglycerin induces a decrease in the systemic arterial and perfusion pressure. No species differences in the manifestations of the nitroglycerin pharmacological effect confirmed in the principle the common organization of the adrenergic mechanisms that control the cardiovascular system. Nitroglycerin is effective for prevention and therapy of cerebral angiospasms.

[Complex study of the hemodynamics, impedance, and bioelectrical activity of the brain of patients with parasagittal meningiomas]. / Kompleksnoe issledovanie gemodinamiki, impedansa i bioélektricheskoi aktivnosti golovnogo mozga u bol'nykh s parasagittal'nymi meniongiomami.

Combined use of radioisotope and impedance methods in the examination of cerebral and peripheral circulation and EEG recording in 40 patients with parasagittal meningiomas revealed a correlation between the rheographic characteristics of the tonus and blood filling of the cerebral vessels and the quantitative values of cerebral hemodynamics. Specific features of cerebral circulatory disorders characteristic of parasagittal tumors were revealed before operation and in the postoperative period. The prognostic significance of examination of the cerebral blood flow and impedance in the early postoperative period is demonstrated.

[Clinico-physiologic analysis of the effect of decompressing the cerebrospinal fluid system in children with hydrocephalus]. / Kliniko-fiziologicheskii analiz vliianiia rezgruzki likvornoi sistemy pri gidrotsefalii u detei

Changes in vascular tonicity and blood filling in the brain were studied in 26 children with occlusive hydrocephalus during ventricular punctures and following surgical elimination of the occlusion. The nature of the reactive changes in the tonicity and blood filling of the cerebral and peripheral vessels was found to be different in response to the draining of the CSF system depending on the level of thebrain lesion. Following ventricular punctures with CSF draining the majority of the examined demonstrated a normalization of their elevated tonicity of the cerebral vessels and a disappearance of hampered venous drainage. The dynamics of the vascular responses developing under the effect of dehydration agents is characterized by the maximum response 30-50 min following the administration of the drug and by a gradual restoration of the initial state some 2-2 1/2 hours later.

[Correlation between the circulation of the hemispheres and brain stem regions, the peripheral circulation and bioelectrical activity of the brain in the dynamics of the acute period of cranio-cerebral injury]. / Sootnoshenie mezhdu krovoobrashcheniem polusharii i stvolovykh otdelov mozga, perifericheskim krovoobrashcheniem i bioélektricheskoi aktivnost'iu golovnogo mozga v dinamike ostrogo perioda cherepno-mozgovoi travmy

Polygraphic recording of rheoencephalography, rheovasography and EEG was used for a dynamic examination of 45 patients with severe (28 cases) and moderate (17 cases) craniocerebral injuries. In 13 patients, of the former group intracranial haematomas were noted, in 15--contusion foci. A method of rheoencephalography recording from the brain stem with the aid of a basal electrode was developed, and it permitted to obtain valuable information on the degree of the haemodynamic shifts in the brain stem. A persistent reduction of the CBF was observed in the basalocciptal lead found to be proportional to the severity of the craniocerebral injury. The results of mathematical processing of the obtained data demonstrated a clear correlation of the clinical state of the patient, the bioelectrical activity of the brain and the indices of the tonicity and blood filling of the cerebral vessels: along with re-establishment of the normal alpha-rhythm and reduction of a slow pathological activity of the EEG, a clear increase in the cerebral blood flow value was observed.

[The adequacy of the rheoencephalographic method in clinical practice and research]. / Issledovanie adekvatnosti reoéntsefalograficheskogo metoda v klinke i v éksperimente

For purposes of defining the adequacy of using REG registrations in clinical practice, the authors conducted 4 series of studies on normals (16 cases), in patients of a neurosurgical ward (39 cases) and in experimental animals (12 dogs). The experimental and clinical studies displayed that the mechanical pulse fluctuation of the skin was not the determining factor in the genesis of a REG. The authors have come to the conclusion that the time of distribution of the pulse wave by itself can not serve as an indicator of an extra-or intracranial origination of REG waves inasmuch as it is different in different brain areas and depending upon its remoteness from the heart and the state of the vascular tone. Using the occlusional cuff the authors calculated the portion of the extracranial item in the total amount of the wave amplitude in the REG in norms (in average 14%). Thus, the achieved data confirmed the adequacy of the REG as a method of studying the pulse blood flux and cerebral vascular tone.