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Aspirin in the secondary prevention of ischemic stroke
Adámek, Tomáš ; Alušík, Štefan (advisor) ; Kalvach, Pavel (referee) ; Souček, Miroslav (referee)
Introduction: The recurrence of the cerebral ischemic stroke after a history of TIA or ischemic stroke is 3-4% per year. One way of reducing the risk of reccurence is using antiplatelet therapy. The aim of our study was to investigate the effect of aspirin. Even though, newer antiplatelet drugs were developed, their risk/benefit profile has not been proved to be better than aspirin. Reasons for using aspirin in secondary prevention are: the longest experience, clearly proven effect in many studies and low price. On the other hand, aspirin prevents only 25% of strokes, thus there is wide space for searching for causes of failed therapy and alternative therapeutic ways. Noncompliance of aspirin use and embolic events are usually indicated as the most common causes of an ineffective therapy. The goal of our study was to find the antiplatelet therapy effectivity in patients with history of stroke treated with aspirin in daily dose of 100mg. We assured 100% compliance among these patients and as much as possible minimalized a likelihood of embolic causes of strokes. What is more, we tried to find out whether an insuffient suppression of 11-dehydrotromboxane B2 correlates with comorbidities, other used medication or laboratory parameters. Furthermore, whether by administrating an increased dose of...
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Magnetic resonance imaging of central nervous system lymphoma.
Koubská, Eva ; Malíková, Hana (advisor) ; Kalvach, Pavel (referee) ; Druga, Rastislav (referee)
Background: The aim of this study was to describe the morphological signs of the central nervous system lymphoma (CNSL) in magnetic resonance imaging (MRI). We compared morphological characteristics of primary CNSL (PCNSL) and secondary CNSL (SCNSL) and also of PCNSL and glioblastoma (GBM). Methods: We included 64 patients with PCNSL (ten of them were immunocompromised), 21 patients with SCNSL and 54 patients with GBM. The diagnosis was confirmed histologically in all patients. We evaluated morphological signs on the first MRI examination. Additionally, in patients with PCNSL, we evaluated the development of the disease on follow-up examination before histological confirmation of the diagnosis, if available. Results: In most patients with PCNSL (62.5%) the tumor was localized supratentorially and presented as multiple lesions (53.1%) or as a diffuse infiltrative lesion (23.4%). In 87.5% of the patients the lesions reached the brain surface. Infiltration of ependyma was seen in 56.3%, infiltration of meninges in 39.1% and infiltration of cranial nerves in 48.5% of patients. Restriction of diffusion in some part of the tumor was apparent in nearly all patients (97.6%) with PCNSL. After administration of contrast media, marked enhancement was usually seen. In immunocompetent patients, homogenous...
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Aspirin in the secondary prevention of ischemic stroke
Adámek, Tomáš ; Alušík, Štefan (advisor) ; Kalvach, Pavel (referee) ; Souček, Miroslav (referee)
Introduction: The recurrence of the cerebral ischemic stroke after a history of TIA or ischemic stroke is 3-4% per year. One way of reducing the risk of reccurence is using antiplatelet therapy. The aim of our study was to investigate the effect of aspirin. Even though, newer antiplatelet drugs were developed, their risk/benefit profile has not been proved to be better than aspirin. Reasons for using aspirin in secondary prevention are: the longest experience, clearly proven effect in many studies and low price. On the other hand, aspirin prevents only 25% of strokes, thus there is wide space for searching for causes of failed therapy and alternative therapeutic ways. Noncompliance of aspirin use and embolic events are usually indicated as the most common causes of an ineffective therapy. The goal of our study was to find the antiplatelet therapy effectivity in patients with history of stroke treated with aspirin in daily dose of 100mg. We assured 100% compliance among these patients and as much as possible minimalized a likelihood of embolic causes of strokes. What is more, we tried to find out whether an insuffient suppression of 11-dehydrotromboxane B2 correlates with comorbidities, other used medication or laboratory parameters. Furthermore, whether by administrating an increased dose of...
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Age dependent decrease of cerebro-vascular reactivity and its impact on brain parenchyme integrity
Peisker, Tomáš ; Kalvach, Pavel (advisor) ; Zvěřina, Eduard (referee) ; Hort, Jakub (referee)
Summary: Sufficient vasodilatory and vasoconstrictive reactivity of cerebral arterioles is an important prerequisite for adequate capillary perfusion. To appreciate its capacity during aging and to elucidate its impact on parenchymal integrity we undertook a correlation using ultrasonography and brain MRI. Sixty healthy persons with no stenoses in carotid and vertebral arteries were examined by transcranial doppler ultrasonography (TCD) to assess middle cerebral artery mean flow velocities (MFV) et rest, after 30 sec apnea and after 90 sec hyperventilation. Young persons, N=20, mean age 24,8 (20- 32) were compared with middle aged, N=20, 54,8 (40-63) and elderly, N=20, 76,2 (69-84). A cohort of 40 elderly persons, mean age 68,4 (57-85) were evaluated also by MRI using FLAIR and T2-weighted sequences. Their extent of leukoaraiosis measured by the Fazekas scale was correlated with their vasoregulatory capacity. Results: The steady state mean flow velocity (MFV) in young persons, 71 cm/sec, decreases to 48,1 and to 44,9 cm/sec in the middle and the old aged. The postapnoic vasodilatation in young persons accelerates the MCA blood velocity by 41,7%, while in middle and old age only by 37,9 and 32,7% respectively. The MCA deceleration post hyperventilation by 49,8% in young people decreases to 37,8% and to 29,7%...
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Stenting of carotid stenoses with distal protection device and intravascular ultrasound
Lacman, Jiří ; Krajina, Antonín (advisor) ; Kalvach, Pavel (referee) ; Sameš, Martin (referee)
Stenting of carotid stenoses with distal protection device and intravascular ultrasound Carotid artery stenting is generally accepted and less invasive alternative to surgical endarterectomy for indicated patients. The goal of the treatment is to prevent strokes and subsequent neurological problems. This paper introduces the current state of this method of intervention, its indications and specifically addresses the issue of possible uses and benefits of intravascular ultrasound ( IVUS) and virtual histologization (VH ) in the diagnosis of carotid stenosis and atherosclerotic plaque and treatment of carotid artery stenosis. The author performed 119 IVUS examinations on 110 patients, 33 of these examinations were made virtual histologization of plaque. Periprocedural complications were observed during IVUS examination and stenting. Using the virtual histologization, atherosclerotic carotid plaques were classified into types according to their composition (risk vs . risk-free plaques) and correlated with the length of stenosis and percentage of stenosis. In the IVUS group there were 80 men and 30 women, the average age was 72 years, symptomatic carotid artery was examined in 69 cases (58 %), asymptomatic in 50 cases (42 %). To the IVUS -VH group were counted 33 patients who underwent 35 examinations....
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Ischemic strokes in vertebrobasilar region, caused by lesions of magistral arteries
Škoda, Ondřej ; Kalvach, Pavel (advisor) ; Šonka, Karel (referee) ; Kemlink, David (referee)
Vertebrobasilar ischemic strokes, caused by lesions of magistral arteries. Background and Purpose Progress in modern non-invasive or minimally invasive diagnostic methods has improved detection and evaluation of pathological changes in the vertebral arterial system. Ischemia in vertebrobasilar circulation, often caused by stenotic processes of vertebral arteries, is considered a severe form of stroke, with a mortality of 20 - 30%. Stenoses of these arteries may be responsible for up to one half of ischemic events in their nutritive region. Although there is no general consensus on treatment of the VA stenoses so far, recent recommendations consider interventions in secondary stroke prevention, when optimal conservative treatment did not prevent recurrent clinical symptoms. With the increasing number of centers providing diagnostics and possible interventional treatment, the objective assessment of these lesions should be available. However, due to a relatively small part of patients, who are indicated to vertebral angioplasty, the diagnostic procedures should be as noninvasive and safe, as possible. The aim of this study was to create the accurate, noninvasive an safe diagnostic algorithm for the detection and evaluation of the VA stenoses and to test its reliability on our own patients group....
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A comparison of various systems of urgent care and their future directions
Pokorný, Jiří ; Čelko, Alexander (advisor) ; Kalvach, Pavel (referee) ; Špunda, Jan (referee)
While a relatively young field of medicine, emergency care (EC) has recently witnessed dramatic advances which will definitely continue. At present, there are 2 main systems of EC provision, the Anglo-American and the Franco-German ones. Both systems have their indisputable advantages; however, they are also fraught with major drawbacks. Given my long-term personal experience with emergency medical service as well as my appointments in hospital resuscitation wards, emergency departments, and operating theaters, I am convinced there is still considerable room for improvement in the organization of pre- and in-hospital EC in our country. To develop this thesis, I have collected as much as possible information about the organization of EC in various countries of the world and in the CR. Based on my knowledge and data from the above sources and, also, using my long-standing experience, I have evaluated and compared individual EC systems assessing both their advantages and disadvantages. The analysis has shown that the system of EC should meet both the geopolitical and economic status of the country involved, and the standard of currently available therapeutic options. The outcome of my study is a proposal to modify the system of EC in the CR. It should be an adaptable system, with its main advantage being it...
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Neurobiological foundations of language comprehension system: Embodied cognition
Kubík, Tomáš ; Macurová, Alena (advisor) ; Kalvach, Pavel (referee) ; Mertins, Barbara (referee)
Dissertation Neurobiological foundations of language comprehension system: Embodied cognition Abstract First part of the dissertation describes classical neuroanatomical structures of language processing. From an anatomical perspective, language comprehension system consists of many cortical and subcortical areas. Currently, new technologies depict pictures of bundles of nerve fibres connecting the brain eloquent structures. This line of research supports ideas about cognitive functions mediated by large neuronal networks. Part two focuses on the description of several important non-linguistic cognitive systems that are involved in the analysis of spoken language. Another aim of this part of the text is to monitor the actual language representations and their processing in the language comprehension system. Comprehension is viewed as a process of advancing from perception to creation of mental images (simulations) representing the outcome of this process in a healthy population. Part three takes into account lesion studies that are primarily focused on the manifestations of specific language symptoms in people with aphasia, right hemisphere damage, and dementia. The three distinct neurological units (in terms of damage localization) constitute three different types of disturbances in language understanding...
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Diffusion Weighted Imaging and Other Quantitative MRI Methods in the Diagnostics of Selected CNS Diseases
Keller, Jiří ; Kalvach, Pavel (advisor) ; Hluštík, Petr (referee) ; Hájek, Milan (referee)
The aim of this study was to assess the scope of exploitation of the diffusion weighted imaging and other quantitative MR methods in the clinical diagnostics. We calculated the normal values of fractional an- isotropy (FA) in our group of healthy volunteers and proved FA depen- dence on age in some regions of brain using regression analysis. The relationship was quadratic in the splenium of callosal body, the left pre- central gyrus and in the pyramidal tract at the level of mesencephalon on the right. Linear decrease of FA with age was found in the rostrum of callosal body, in the white matter of frontal lobes, in the anterior limb of internal capsule on both sides and in the pyramidal tract at the level of mesencephalon on the left. In all measured parts of basal ganglia FA in- creased. Based on our data set, we propose a non-linear colour look-up table (LUT) to enhance the pathologic values. The use of this LUT is presented in patients with several neurological disorders. Quantitative methods were used also for assessment of the group of patients suffering from ALS. The changes we expected in the posterior limb of internal capsule were not significant, therefore we suppose that the presence of T2 hyperintensity in this region is not a reliable marker of the disease. T2 relaxometry detected the...
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