Investigation of Cerebral Autoregulation Using Time-Frequency Transformations.

The authors carried out the study of the state of systemic and cerebral hemodynamics in normal conditions and in various neurosurgical pathologies using modern signal processing methods. The results characterize the condition for the mechanisms of cerebral circulation Institute of Computer Science and Control, Higher School of Cyber-Physical Systems and Control regulation, which allows for finding a solution to fundamental and specific clinical problems for the effective treatment of patients with various pathologies. The proposed method is based on the continuous wavelet transform of systemic arterial pressure and blood flow velocity signals in the middle cerebral artery recorded by non-invasive methods of photoplethysmography and transcranial doppler ultrasonography.

Perioperative Dynamics of Intracranial B-waves of Blood Flow Velocity in the Basal Cerebral Arteries in Patients with Brain Arteriovenous Malformation.

Intracranial B-waves (8-30 mHz) of blood flow velocity (BFV) in the cerebral arteries are observed in various pathologies of the brain. Changes in B-waves of BFV in pathological arteriovenous shunting and "steal" syndrome remain poorly understood. The aim of this study was to evaluate the dynamics of the B-wave amplitude of BFV (BWA) in patients with an arteriovenous malformation (AVM) in the brain.

Predictive Value of Dynamic Cerebral Autoregulation Assessment in Surgical Management of Patients with High-Grade Carotid Artery Stenosis.

Dynamic cerebral autoregulation (DCA) capacity along with the degree of internal carotid artery (ICA) stenosis and characteristics of the plaque can also play an important role in selection of appropriate treatment strategy. This study aims to classify the patients with severe ICA stenosis according to preoperative state of DCA and to assess its dynamics after surgery. Thirty-five patients with severe ICA stenosis having different clinical type of disease underwent reconstructive surgery.

[Severe carotid stenosis: cerebral autoregulation in the ipsilateral region].

Aim: To study cerebral autoregulation (CA) in region of the stenotic carotid artery.

Material And Methods: The study involved 35 patients with critical stenosis of the carotid arteries, including 24 patients were asymptomatic and 11 patients with symptomatic course. Blood flow velocity in middle cerebral arteries was monitored using Multi Dop X (DWL, Germany) with simultaneous noninvasive systemic blood pressure registration (CNAP, Austria).

Effects of iodinated contrast media in a novel model for cerebral vasospasm.

Objective: We developed an in vitro model for vasospasm post subarachnoid hemorrhage that was suitable for investigating brain vessel autoregulation. We further investigated the effects of iodinated contrast medium on the vascular tone and the myogenic response of spastic cerebral vessels.

Method: We isolated and perfused the superior cerebellar arteries of rats.

The intracranial B-waves' amplitude as prognostication criterion of neurological complications in neuroendovascular interventions.

The purpose of this study was to evaluate dynamics of B-waves' amplitudes (BWA) of blood flow velocity (BFV) in patients with cerebrovascular diseases during endovascular operations. We examined 12 patients with neurovascular pathology during neuroendovascular interventions. Patients were divided into two groups: 1st group (6 cases)--without intraoperative neurological complications, 2nd group (6 cases)--with complications.

Kininogen consumption in cerebral circulation of humans during brain ischemia and postischemic reperfusion.

1. Total kininogen, high molecular weight kininogen and low molecular weight kininogen were quantitated as bradykinin equivalents in the blood flowing to and from the brain in patients with stenotic and occlusive carotid damage in the course of neurosurgical treatment. Although considerable improvement in blood supply of ischemic brain areas was established after surgery in all patients, improvement in postoperative neurological status was seen only in four patients (group I), while in six cases there were no or negative neurological changes (group II).

Angioplasty of vasospasm: is it reasonable?

Clinical and radiographic examinations indicate preliminarily indications that transluminal angioplasty may be effective in overall management of the patient with vasospasm. Many questions remain, including: How does it work?; Are the effects persistent?; Is the arterial wall injured by the process? Recent studies in several patients who died after angioplasty allow us to provide some answers. Undilated spastic arteries show proliferation of both cellular and connective tissue elements.