Physiological Parameters in Various Prognosis of the Acute Period of Haemorrhagic Stroke

Study Objective: To identify the differences in physiological parameters in groups of patients in an acute period of haemorrhagic parenchymatous stroke (supratentorial hemisphere hematomas) with favourable outcome and fatality. Study Design: prospective study. Materials and Methods. We have examined 96 patients with supratentorial haemorrhagic stroke. Haemorrhagic stroke was diagnosed on the basis of neuroimaging results, clinical symptoms and medical history, as well as clinical and laboratory data. A cluster analysis and expert examinations made it possible to divide patients into two groups: 49 patients who died of the acute haemorrhagic stroke and 47 patients with a favourable outcome. We evaluated the level of consciousness, cognitive functions, neurophysiological parameters: electroencephalography (EEG), cognitive evoked potentials Р300, heart rate variability (HRV). Study Results. In patients with a favourable outcome, an overall amplitude of the EEG spectrum was higher vs. patients with lethal outcome (statistically significant results were noted in all leads). A significant increase in the mean frequency of theta waves was seen in both groups, especially in the group with lethal outcomes. When Р300 in patients with lethal outcome was evaluated, a significantly lower P2N2 amplitude in Fz was noted vs favourable outcome group: 5.1 (2.6; 9.1) μV vs 8.9 (5.6; 20.4) μV (U = 148; p = 0.021). A comparative analysis of HRV revealed significant differences only in heart rate (mean R-R): it was lower in patients who died in the acute period of haemorrhagic stroke: 696 (608; 836) ms vs 806 (743; 911) ms (U = 181; p = 0.033). In patients with lethal outcomes, there is an increase in the number of linear correlations in physiological parameters vs. favourable outcome group. Conclusion. Deaths from acute haemorrhagic stroke are preceded by reduction in the basic cortical rhythm, growth in slow waves activity, reduction in the stimuli recognition mechanism activation (according to cognitive evoked potentials Р300). An analysis of the rate of correlation in physiological mechanisms of brain activity regulation (EEG), neurophysiological correlates in stimuli recognition and decisionmaking (Р300), as well as autonomic regulation mechanisms (HRV) shows limited functional reserves in patients with lethal outcomes. Keywords: haemorrhagic stroke, event-associated potential, heart rate variability, correlation analysis.</jats:p

NONUNIFORM COURSE OF ACUTE PERIOD OF HEMORRHAGIC STROKE: ANALYSIS USING METHODS OF MULTIVARIATE STATISTICS

Background. Hemorrhagic stroke is an important medical and social problem both in the world and in the Russian Federation due to high parameters of morbidity, mortality and disability. Aim. To compare expert assessments and formalized multivariate statistical procedures in analysis of clinical inhomogeneity of patients with intracranial hematoma of supratentorial location. Materials and Methods. 75 Patients who took treatment in the neurovascular department of Ryazan Regional Clinical Hospital with the diagnosis of hemorrhagic stroke, were examined. Of them, there were 40 men and 35 women with the mean age 68.1 years. Results. Primarily, on the basis of expert assessments, the patients were divided to 2 groups: with unfavorable course and with relatively favorable course – satisfactory condition, regress of symptoms, recovery of the level of consciousness. In the first stage, in result of the primary expert assessment, the patients were divided to subgroups with favorable and unfavorable course. After that, significant for selection of groups variables were used in selection of clusters: method of hierarchial tree for determination of the number of groups; k-means method for identification of their elements. Discrimination analysis was used for selection of variables in NIHSS and GCS, and also for assessment of canonical correlations. After that, cluster analysis of NIHSS and GCS dynamics was conducted on the 1st, 3rd, 21st day for selection of groups in high-dimensional space of signs with exclusion of subjective expert assessments. Three main groups of patients were selected. In the second stage, in accordance with the number of groups, patients belonging to the corresponding clusters were identified using the k-means method. Cluster 1 included patients with a poor prognosis, clusters 2 and 3 suggested a more favorable course of the acute period with worse parameters in cluster 2. Conclusions. Use of discriminant functions confirms the role of severity of depression of consciousness and of the volume of hematoma in the unfavorable course.</jats:p