Patologìâ (Apr 2013)
Cinical, morphological and functional comparisons in acute period of ischemic hemispheric stroke
Abstract
The aim of the research was the optimization of diagnostic and prognostic approaches in patients in acute period of ischemic supratentorial stroke depending on lateralization of lesion focus on the basis of clinical, computed tomography and computed electroencephalography investigations. Objectives of investigation: Detection and specification of electroencephalography violations in acute period of ischemic supratentorial stroke in aspect of lateralization of lesion focus and its influence on contralateral hemisphere; comparative analysis of EEG-pattern with morphological criterions of the lesion focus (based on computed tomography data) and clinical structure in patients with acute period of ischemic supratentorial stroke according to stroke lateralization; estimation of diagnostic and prognostic criteria of stroke course based on the results of indicated investigations according to lateralization of necrobiotic lesion focus. Materials and methods: 90 patients (mean age 66,9±1,17 years) with acute period of ischemic supratentorial stroke were examined clinically and by computed tomography and computed electroencephalography and divided into 2 groups: 1st one – left-side stroke (48 patients – 24 (50%) men and women), 2nd one – 42 patients with right-side stroke (24 (57,1%) men and 18 (42,9%) women). Groups were representative by age and sex. Statistical analysis was made with program Statistica 6.0 with the use of nonparametric methods (Mann-Whitney criterion), correlation analysis (Spearman’s rank correlation coefficient). Results and discussion: EEG-pattern of left-side stroke comparing with right one was characterized with increasing of level of theta-1-subrange spectral rating in intact hemisphere by 12% (р<0,05). Following correlations were revealed: lateralization of medial brain structures - spectral rating of delta-range of affected hemisphere (R=0,38, p<0,05), lateralization of medial brain structures - spectral rating of theta-range of affected hemisphere (R=-0,35, p<0,05), «lateralization of medial brain structures - spectral rating of theta-2-subrange of affected hemisphere» (R=-0,33, p<0,05), the lateral ventricle dilatation - spectral rating of alpha-2-subrange of intact hemisphere (R=0,33, p<0,05). Depression of synchronized systems of diencephalic level is associated with sum of points on NIHSS scale (R=0,38, p<0,05) and value of modified Rankin’s scale (R=0,44, p<0,05) on the 21st day of stroke. Correlation between volume of lesion and level of theta-range spectral rating of affected hemisphere (R=-0,35, p<0,05), spectral rating of theta-2-range rhythm (R=-0,34, p<0,05), alpha-1- (R=-0,36, p<0,05) и alpha-2- (R=-0,35, p<0,05) subranges of affected hemisphere, spectral rating of beta-range rhythm were detected (R=0,35, p<0,05) in patients with right-side stroke. Criteria of desynchronized mesencephalic systems activation were associated with the evidence of neurological deficiency on NIHSS scale at the disease onset. Conclusions. Left-side stroke is characterized by deep depression of synchronizing systems of diencephalic level which is associated with lateral dislocation of midline structures as a result of stroke focus. The feature of left-side stroke was more evident neurological deficiency according to NIHSS scale also. In case of the right-side stroke activation of desynchronizing systems of mesencefalic level, associated with cortical structures of contralateral intact hemisphere was visualized with correlation with the volume of the lesion focus and manifestations of neurological deficiency according to NIHSS scale. It was established that elevation of rhythm in delta-range spectral rating of affected hemisphere in combination with bilateral decreasing of rhythm in alpha-range is the criterion for unfavorable course and outcome of acute ischemic supratentorial stroke.
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