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The influence of deep brain stimulation on the brain connectivity
Horváthová, Ľubica ; Výtvarová, Eva (oponent) ; Klimeš, Petr (vedoucí práce)
The deep brain stimulation (DBS) represents effective treatment for patients with Parkinson’s disease (PD) or patients with pharmacoresistant epilepsy. However its mechanisms by which it moderates seizures and improves movement still remain largely unknown. To understand it better and to determine in which frequency bands is the change most relevant, comparisons between DBS OFF and DBS ON were made using correlation method and phase lag index. Eleven patients with (PD) and with implanted neurostimulators for DBS from the companies Medtronic and St.Jude Medical are the subjects of the recorded data used in this thesis. The results prove that not only does the change in connectivity occur during the DBS, but also that the higher frequencies such as beta, low gamma and high gamma are affected the most. Changes in these frequencies, responsible for motor activity, attentive focusing and information processing, are consistent with the PD clinical findings. During this disease, pathological beta activity is hypersynchronized and gamma activity is reduced in motor areas. With gamma activity increasing during DBS ON, the physiological state of the patients is partially restoring and therefore improving their motility. The methods and results of this thesis will be used for further research on patients with PD and epilepsy.
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Sleep dynamics analysis using electrophysiological features
Lampert, Frederik ; Janoušek, Oto (oponent) ; Mívalt, Filip (vedoucí práce)
This thesis concerns with sleep assessment methods using electrophysiological features without the availability of annotations in the form of hypnograms. Sleep evaluation using polysomnographic (PSG) data is time-consuming process, that requires trained personnel and is usually done in a hospital environment. Novel implantable neural devices capable of continuous data recording and streaming open up possibilities of longitudinal and continual monitoring of sleep activity in a home environment for patients with neural diseases. Current state-of-the-art methods for longitudinal sleep analysis utilizes automated intracranial electroencephalography (iEEG) sleep classifiers developed and validated using clinical gold-standard PSG annotations. However, PSG is not always feasible to perform which leads to the necessity for a sleep assessment method, which could analyse sleep using electrophysiological features without the availability of goldstandard PSG annotations generally from a small number of electrodes. For this purpose a novel sleep assessment method was developed, which evaluates sleep based on the power of electroencephalographic (EEG) signal in the spectral bands with employment of the metrics called Power in Band (PIB) metrics. In this work power in the delta band (0.5-4 Hz) was used, as it has the highest amplitude among all of the bands and is the most prominent during the non-REM sleep states, therefore giving the most relevant information about the composition of sleep during the night. Moreover, standard hypnogram-based metrics were introduced for the purpose of the PIB metrics validation. These metrics were incorporated into (Python) programming language and applied on two publicly-available datasets Dreem Open Dataset-Healthy (DOD-H) and Dreem Open Dataset-Obstructive (DOD-O) containing polysomnographic recordings of 25 healthy subjects (DOD-H) and 56 subjects suffering from obstructive sleep apnea (OSA) (DODO dataset). The results of the analysis were evaluated by visual analysis in terms of boxplots, correlation matrices and statistical tests. From the results, it is possible to assume, that proposed PIB metrics have the ability to differentiate between physiologic and pathophysiologic sleep, although their ability to discriminate between some aspects differs from the metrics based on the hypnogram annotations. This implies the fact, that PIB metrics do not substitute the standard hypnogram-based metric, but rather provide different perspective on the sleep assessment.
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Nitric oxide and its role in neurophysiology
Dobrovodská, Gabriela ; Otáhal, Jakub (vedoucí práce) ; Brime, Tufikameni (oponent)
Súhrn Názov práce: Oxid dusnatý a jeho neurofyziologická rola Ciele práce: Hlavným cieľom diplomovej práce je zhodnotiť rolu oxidu dusnatého a jeho účinky v priebehu epileptického záchvatu u potkanov. V teoretickej časti tejto práce sumarizujem doterajšie poznatky ohľadom oxidu dusnatého a jeho vplyve na organizmus človeka a realizáciou môjho experimentu budem predpokladať pozitívny efekt inhibítoru oxidu dusnatého pri epileptických záchvatoch u potkanoch. Metóda: Experiment bude vykonaný v laboratóriu ústavov Akademie věd Českej republiky. Realizácia prebehne skúmaním súboru desiatich potkanov, šiestim sa aplikuje Nω - propyl-l-arginín (L-NPA) v množstve 0,5mg na jednu stranu, čo sa uskutoční bilaterálne do mozgovej komory. Následne po 10 minutách bude vykonaná aplikácia 4-aminopyridínu (4- AP) do mozgovej komory bilaterálne v množstve 0,5 µl. Kontrolnej skupine pozostávajúcej zo štyroch potkanov bude zavedený namiesto L-NPA fyziologický roztok. Experiment bude prebiehať počas 2 dní. Výsledky: Priebeh epileptického záchvatu s aplikáciou L-NPA skúmanej skupine bol porovnaný s kontrolnou skupinou. Experimentom sa potvrdil pozitívny efekt L-NPA v zmysle oddialenia a zmiernenia záchvatu. Kľúčové slová: oxid dusnatý, Nω -propyl-l-arginín, neurovaskulárny coupling, 4 - aminopyridín, epilepsia
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The influence of deep brain stimulation on the brain connectivity
Horváthová, Ľubica ; Výtvarová, Eva (oponent) ; Klimeš, Petr (vedoucí práce)
The deep brain stimulation (DBS) represents effective treatment for patients with Parkinson’s disease (PD) or patients with pharmacoresistant epilepsy. However its mechanisms by which it moderates seizures and improves movement still remain largely unknown. To understand it better and to determine in which frequency bands is the change most relevant, comparisons between DBS OFF and DBS ON were made using correlation method and phase lag index. Eleven patients with (PD) and with implanted neurostimulators for DBS from the companies Medtronic and St.Jude Medical are the subjects of the recorded data used in this thesis. The results prove that not only does the change in connectivity occur during the DBS, but also that the higher frequencies such as beta, low gamma and high gamma are affected the most. Changes in these frequencies, responsible for motor activity, attentive focusing and information processing, are consistent with the PD clinical findings. During this disease, pathological beta activity is hypersynchronized and gamma activity is reduced in motor areas. With gamma activity increasing during DBS ON, the physiological state of the patients is partially restoring and therefore improving their motility. The methods and results of this thesis will be used for further research on patients with PD and epilepsy.
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Nitric oxide and its role in neurophysiology
Dobrovodská, Gabriela ; Otáhal, Jakub (vedoucí práce) ; Brime, Tufikameni (oponent)
Súhrn Názov práce: Oxid dusnatý a jeho neurofyziologická rola Ciele práce: Hlavným cieľom diplomovej práce je zhodnotiť rolu oxidu dusnatého a jeho účinky v priebehu epileptického záchvatu u potkanov. V teoretickej časti tejto práce sumarizujem doterajšie poznatky ohľadom oxidu dusnatého a jeho vplyve na organizmus človeka a realizáciou môjho experimentu budem predpokladať pozitívny efekt inhibítoru oxidu dusnatého pri epileptických záchvatoch u potkanoch. Metóda: Experiment bude vykonaný v laboratóriu ústavov Akademie věd Českej republiky. Realizácia prebehne skúmaním súboru desiatich potkanov, šiestim sa aplikuje Nω - propyl-l-arginín (L-NPA) v množstve 0,5mg na jednu stranu, čo sa uskutoční bilaterálne do mozgovej komory. Následne po 10 minutách bude vykonaná aplikácia 4-aminopyridínu (4- AP) do mozgovej komory bilaterálne v množstve 0,5 µl. Kontrolnej skupine pozostávajúcej zo štyroch potkanov bude zavedený namiesto L-NPA fyziologický roztok. Experiment bude prebiehať počas 2 dní. Výsledky: Priebeh epileptického záchvatu s aplikáciou L-NPA skúmanej skupine bol porovnaný s kontrolnou skupinou. Experimentom sa potvrdil pozitívny efekt L-NPA v zmysle oddialenia a zmiernenia záchvatu. Kľúčové slová: oxid dusnatý, Nω -propyl-l-arginín, neurovaskulárny coupling, 4 - aminopyridín, epilepsia
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