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Software for automatic data extraction in analysis of brain connectivity
Bujnošková, Eva ; Schwarz, Daniel (referee) ; Jan, Jiří (advisor)
The brain; complex system people want to know about but still they are at the beginning of understanding it. There has been a lot of neuroimaging systems since developement of modern technologies and magnetic resonance imaging is one of them. In last days it isn't enough to examine only structural character of brain, the scientists are dealing with functional states more and more; the functional magnetic resonance imaging is perfectly good tool for this. There is a big amount of researches concerning individual brain regions but also a lot of them dealing with communication across the brain to clear up the causes of human behavior and functional failures. This thesis introduces the brain connectivity exploration, it uses the parcellation by anatomical atlases and it tries to use the knowledge of graph theory as one of the options to determine relations between brain centres and regions. The thesis introduces the software created for extraction of connectivity matrix resulting in graph processing and visualization.
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Hemodynamic model in effective brain connectivity analysis using fMRI
Holeček, Tomáš ; Harabiš, Vratislav (referee) ; Lamoš, Martin (advisor)
Modeling of hemodynamic response based on changes of synaptic activity is used for mapping active areas of the brain or functional organization of the brain using functional magnetic resonance imaging. Hemodynamic model is one of the methods for modeling hemodynamic response. Balloon model is the main part of the hemodynamic model. Hemodynamic model is used in the mapping active areas using general linear model and in the effective brain connectivity analysis using dynamic causal modelling. This bachelor´s thesis is focused on description of the hemodynamic model, its parameters and impact of every single parameter of the hemodynamic model on its response.
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The influence of morphometric changes of gray and white matter on brain functional connectivity in schizophrenia
Görnerová, Natálie ; Horáček, Jiří (advisor) ; Zach, Petr (referee) ; Filip, Pavel (referee)
More than a century has passed since a clear definition for schizophrenia was established, yet, the etiology, neuropathological and pathophysiological mechanisms of this psychiatric disorder still, to a large extent, remain to be elucidated. In the theoretical part of this dissertation, we review current classification and pathophysiology of schizophrenia, paying a particular attention to the findings from structural and functional imaging techniques. These techniques demonstrate that patients with schizophrenia tend to have reduced volume of grey matter, reduced integrity of white matter and a disrupted inter-regional functional connectivity (FC). The temporal association between structural changes, already detectable on imaging before symptoms appear, and development of disrupted FC remains to be uncovered. At the same time, current knowledge does not fully explain the link between disrupted FC and disturbed experience of self-awareness, a core symptom of schizophrenia. In addition, it is necessary to develop novel effective methods to prevent relapse and prevent the progression of neurobiological changes in the brain. In the practical part of this dissertation, we designed a study with three different groups of subjects aiming to fulfil three key aims that would help us to fill the gaps in...
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Detection of neuronal activity associated with function of lower urinary tract with use of functional magnetic resonance imaging
Holý, Petr ; Zachoval, Roman (advisor) ; Hanuš, Tomáš (referee) ; Mašata, Jaromír (referee)
of the thesis Considerable research attention has been paid to the neural regulation of the lower urinary tract (LUT) in past three decades. The aim of this work is mapping of a brain activity by functional magnetic resonance imaging (fMRI) using refined scanning protocol with synchronously performed urodynamics. We aimed to detect neural activity associated with pelvic floor muscle (PF) contractions, filling of urinary bladder and miction. In addition we evaluated using fMRI brain activity associated with urinary bladder filling in patients with a complete spinal cord injury (SCI). We hypothesized activation of brainstem and forebrain areas in receiving information from the vagal nerves. Adjustments of urodynamic system enabled successful implementation of synchronous filling cystometry with fMRI evaluation of cortical activity. We concluded that synchronous urodynamic examination is a novel feasible method that facilitates and enhance interpretation of fMRI data acquired. The main clusters of brain activation during PF contractions were observed in the medial surface of the frontal lobe (primary motor area) and supplementary motor area (SMA). We detected neural activity associated with filling of urinary bladder and miction in middle and inferior frontal gyrus, angular gyrus, posterior and...
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Neuromodulation in treatment of selected dystonic syndromes
Havránková, Petra ; Jech, Robert (advisor) ; Štětkářová, Ivana (referee) ; Rokyta, Richard (referee)
Dystonia is a neurological syndrome characterized by the involuntary contraction of opposing muscles, causing twisting movements or abnormal postures (modified by Fahn, 1987). Writer's cramp is the most common form of task-specific focal dystonia. In the first study, patients with writer's cramp were evaluated for differences in cortical activation during movements likely to induce cramps (complex movements) and movements which rarely lead to dystonia (simple movements). Although complex patient movements during fMRI were never associated with dystonic cramps, they exhibited abnormally decreased cortical activity. This was not observed in simple movements and was unrelated to the character of handwriting or the presence/absence of visual feedback. Our results support the theory of dualistic sensorimotor system behavior in writer's cramp. As the somatosensory system is believed to be affected in focal dystonia, we focused on modulation of the primary somatosensory cortex (SI) induced by repetitive transcranial magnetic stimulation (rTMS) in the second study, in order to improve writer's cramp. In conclusion, 1 Hz rTMS of the SI cortex can improve manifestations of writer's cramp while increasing cortical activity in both hemispheres. Handwriting as well as subjective assessment improved in most...
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Detection of neuronal activity associated with function of lower urinary tract with use of functional magnetic resonance imaging
Holý, Petr ; Zachoval, Roman (advisor) ; Hanuš, Tomáš (referee) ; Mašata, Jaromír (referee)
of the thesis Considerable research attention has been paid to the neural regulation of the lower urinary tract (LUT) in past three decades. The aim of this work is mapping of a brain activity by functional magnetic resonance imaging (fMRI) using refined scanning protocol with synchronously performed urodynamics. We aimed to detect neural activity associated with pelvic floor muscle (PF) contractions, filling of urinary bladder and miction. In addition we evaluated using fMRI brain activity associated with urinary bladder filling in patients with a complete spinal cord injury (SCI). We hypothesized activation of brainstem and forebrain areas in receiving information from the vagal nerves. Adjustments of urodynamic system enabled successful implementation of synchronous filling cystometry with fMRI evaluation of cortical activity. We concluded that synchronous urodynamic examination is a novel feasible method that facilitates and enhance interpretation of fMRI data acquired. The main clusters of brain activation during PF contractions were observed in the medial surface of the frontal lobe (primary motor area) and supplementary motor area (SMA). We detected neural activity associated with filling of urinary bladder and miction in middle and inferior frontal gyrus, angular gyrus, posterior and...
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Perception of space in virtual reality environments
Fajnerová, Iveta ; Vlček, Kamil (advisor) ; Vavrečka, Michal (referee)
This thesis attempts to analyze spatial perception for navigation in a virtual arena and to cover neuronal basics of distance estimation. For this purpose, we created a virtual version of Hidden goal task which is an analogy to Morris water maze. The thesis presents results of the experiment with removing orientation cues in a circular arena. The aim of the experiment was to determine, if the assumption of Cognitive mapping theory about orientation cues equivalence is valid for our arena. Experiment outcome indicates that the accuracy of goal position estimation is not only influenced by the number of cues but also by the individual hierarchy of the cues. The hierarchy emerges from the distance of the cue from the goal, although in some cases it can be affected by an outstanding identity of the particular cue. These findings are a basis for the experiment utilizing the functional magnetic resonance method to determine neuronal basics for estimating distances in virtual arena in both the egocentric and allocentric reference frame. Results support the findings of the cited papers about the participation of occipital and parietal lobe in estimating object distance in space. Comparison of the two reference frames showed that whereas the egocentric estimation is related to activity in premotor cortex,...
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Neuromodulation in treatment of selected dystonic syndromes
Havránková, Petra ; Jech, Robert (advisor) ; Štětkářová, Ivana (referee) ; Rokyta, Richard (referee)
Dystonia is a neurological syndrome characterized by the involuntary contraction of opposing muscles, causing twisting movements or abnormal postures (modified by Fahn, 1987). Writer's cramp is the most common form of task-specific focal dystonia. In the first study, patients with writer's cramp were evaluated for differences in cortical activation during movements likely to induce cramps (complex movements) and movements which rarely lead to dystonia (simple movements). Although complex patient movements during fMRI were never associated with dystonic cramps, they exhibited abnormally decreased cortical activity. This was not observed in simple movements and was unrelated to the character of handwriting or the presence/absence of visual feedback. Our results support the theory of dualistic sensorimotor system behavior in writer's cramp. As the somatosensory system is believed to be affected in focal dystonia, we focused on modulation of the primary somatosensory cortex (SI) induced by repetitive transcranial magnetic stimulation (rTMS) in the second study, in order to improve writer's cramp. In conclusion, 1 Hz rTMS of the SI cortex can improve manifestations of writer's cramp while increasing cortical activity in both hemispheres. Handwriting as well as subjective assessment improved in most...
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Hemodynamic model in effective brain connectivity analysis using fMRI
Holeček, Tomáš ; Harabiš, Vratislav (referee) ; Lamoš, Martin (advisor)
Modeling of hemodynamic response based on changes of synaptic activity is used for mapping active areas of the brain or functional organization of the brain using functional magnetic resonance imaging. Hemodynamic model is one of the methods for modeling hemodynamic response. Balloon model is the main part of the hemodynamic model. Hemodynamic model is used in the mapping active areas using general linear model and in the effective brain connectivity analysis using dynamic causal modelling. This bachelor´s thesis is focused on description of the hemodynamic model, its parameters and impact of every single parameter of the hemodynamic model on its response.
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Software for automatic data extraction in analysis of brain connectivity
Bujnošková, Eva ; Schwarz, Daniel (referee) ; Jan, Jiří (advisor)
The brain; complex system people want to know about but still they are at the beginning of understanding it. There has been a lot of neuroimaging systems since developement of modern technologies and magnetic resonance imaging is one of them. In last days it isn't enough to examine only structural character of brain, the scientists are dealing with functional states more and more; the functional magnetic resonance imaging is perfectly good tool for this. There is a big amount of researches concerning individual brain regions but also a lot of them dealing with communication across the brain to clear up the causes of human behavior and functional failures. This thesis introduces the brain connectivity exploration, it uses the parcellation by anatomical atlases and it tries to use the knowledge of graph theory as one of the options to determine relations between brain centres and regions. The thesis introduces the software created for extraction of connectivity matrix resulting in graph processing and visualization.
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