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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
311

Development of a HPLC method for the detection of Levetiracetam in blood of patients with epilepsy

Engelbrecht, Lynette 05 1900 (has links)
M. Tech. (Biomedical technology, Faculty of Applied and Computer Science), Vaal University of Technology / Approximately 1% of the world’s population has epilepsy, the second most common neurological disorder after stroke. In South Africa almost 1 in every 100 people has epilepsy, affecting all ages. Levetiracetam (LEV), marketed as Keppra® is an anticonvulsant drug used in the treatment of epilepsy. The daily dosage is 500 mg twice daily with a maximum of 3000 mg. The therapeutic range of LEV is between 12-46 μg/ml. Therapeutic drug monitoring (TDM) should be considered for LEV in patients with poor seizure control or long term treatment. TDM depends on accurate drug concentration measurements. In order to provide an accurate measurement, the High performance liquid chromatography (HPLC) method was developed, compared with a commercially available kit, and the stability of the samples was investigated. Ethical approval was obtained from the Human Research Ethics Committee (Medical), VUT (Ethics reference number: 2015024.4). The study was conducted from January to October 2015. This study involved three groups of volunteers who gave written consent. The first group were fifteen healthy MTech students in the Biomedical Technology Department at the Vaal University of Technology (VUT). Their blood samples were used for the analytical validation of the method and for the stability studies over a 4 weeks period. The second group were six patients from Pathcare Laboratories in Potchefstroom, Klerksdorp and Vereeniging who used Levetiracetam. Their blood samples were used to investigate the influence of different collection tubes as well as the handling and storage of samples on the LEV concentration. The third group were forty four patients from Pathcare Laboratories, Cape Town. Their blood samples were transported to Clinical Pharmacokinetic Laboratory (CPL) for routine therapeutic drug monitoring analysis of LEV and used to compare the newly developed HPLC method and the Commercial kit. The HPLC method was successfully developed and validated to determine LEV in human plasma/serum samples. The calibration curves showed good linearity (r2 = 0,999) over the concentration range of 1 – 60 μg/ml. Accuracy, mean extraction recovery, lower limit of detection (LLOD) and lower limit of quantification (LLOQ) were 98-112%, 97,15% (±1,57), 0,5 and 1,0 μg/ml respectively, in plasma standards. The method was shown to be simple and fast, reproducible and effective for routine laboratory analyses in the future. The agreement between the newly developed method and the ClinRep® HPLC complete commercial kit was the same and there was a statistical significant correlation between the two methods (average r=0.999; p-value < 0.0001, F-test with a true value =0). The method was much cheaper than the commercial kit, used less sample (100 μl) and had a longer running time (15 minutes) to ensure no endogenous interference. The costs of the developed method was 71-82% lower than the three commercial kits available in South Africa. Stability experiments were performed to evaluate the stability of LEV in human plasma/serum, simulating the same conditions which occurred during study samples’ analyses. The % RSD was lower than 5% under all the conditions: freeze, fridge, room temperature and auto sampler over the 4 week period. The results showed that both LEV and the I.S (internal standard) were stable in human serum/plasma under all these conditions. The influence of five different collection tubes, Gold (SST Gel), Red, Purple (EDTA)Green (Heparin) and Blue (Sodium Citrate) was investigated. In two patients, decreased levels were observed in tubes containing blue (sodium citrate) and Green (Heparin). The decrease was not statistically significant. This is an important observation and is an indication that anticoagulants may cause some problems due to drug-protein binding and interference in the matrix effect. A cost effective and reliable HPLC-method with minimal sample preparation time for the routine determination of LEV in plasma/serum samples was developed. It was also shown that the plasma/serum samples were stable at different temperatures over a time period. The only collection tubes that may interfere with the concentrations were the Green (Heparin) and Blue (Sodium Citrate) tubes.
312

Cirugía de epilepsia en patología dual abordada con estimulación cortical directa y electrocorticografía intraoperatoria. Primer caso en el Hospital Rebagliati

Barreto Acevedo, Elliot, Becerra Zegarra, Alicia, Villafuerte Espinoza, Mirla V., Llaja Rojas, Victoria 06 1900 (has links)
La coexistencia de esclerosis hipocampal con una lesión extrahipocampal potencialmente epileptógena, situación conocida como patología dual, traza un reto para planificar la cirugía resectiva de epilepsia farmacorresistente. Presentamos un caso de epilepsia focal farmacorresistente asociada a patología dual (esclerosis hipocampal izquierda y gliosis frontal izquierda), abordada con estimulación eléctrica cortical directa y electrocorticografía intraoperatoria, con buenos resultados a corto plazo. / The coexistence of hippocampal sclerosis with a potentially epileptogenic extra hippocampal injury is known as dual pathology, and presents a challenge to resection surgery strategies in cases of drug-resistant epilepsy. We present a case of drug-resistant focal epilepsy associated with dual pathology (left hippocampal sclerosis and left frontal gliosis), treated by means of direct cortical electrical stimulation and intraoperative electrocorticography with good short-term results.
313

Epilepsia reflexa evacuatória: revisão de literatura e descrição de caso clínico com registro de crise ao vídeo-eletroencefalograma / Reflex epilepsy induced by defecation: literature review and clinical case report

Rocha, Renata Pina 14 June 2017 (has links)
Introdução: a epilepsia reflexa é uma condição na qual todas as crises são desencadeadas por um estímulo específico e, na grande maioria dos casos, apresenta-se com crises refratárias ao tratamento. São vários os fatores desencadeantes, entre os quais se destaca pela raridade a evacuação. Objetivos: realizar revisão de literatura sobre epilepsia reflexa, identificar a evacuação como possível fator desencadeador de crise epiléptica e relatar o caso de um paciente com crise reflexa evacuatória documentada à monitorização por vídeo-eletroencefalograma Métodos: revisão de literatura acerca de epilepsias reflexas e revisão de prontuário de um paciente com suspeita clínica de epilepsia reflexa evacuatória. Resultados: o paciente deste estudo, um menino de 10 anos de idade, com dominância manual esquerda, iniciou, aos 4 anos, crises associadas à evacuação. Na monitorização por vídeo-eletroencefalograma, durante episódio de evacuação, apresentou parada comportamental, desvio cefálico para a direita, automatismos em membro superior esquerdo e arresponsividade, coçando o nariz tardiamente com a mão esquerda. O EEG ictal demonstrou atividade rítmica teta em região temporal esquerda com posterior envolvimento frontal esquerdo e de áreas homólogas contralaterais. As ressonâncias magnéticas de encéfalo não evidenciaram alterações e o SPECT interictal identificou hipoperfusão discreta na porção anterior do lobo temporal esquerdo. Com uso de ácido valpróico e carbamazepina o paciente segue livre de crises. Avaliações neuropsicológicas e de qualidade de vida sugerem comprometimento global, tanto antes como após o controle da epilepsia. Conclusão: este é apenas o terceiro caso de epilepsia reflexa evacuatória descrito na literatura, e o segundo com crises dessa ordem documentadas por vídeo-eletroencefalograma. Ambos sugeriram lateralização e localização em região temporal esquerda, elegendo esta região como potencial zona epileptogênica. O tratamento com ácido valpróico e carbamazepina mostrou-se eficaz para controle de crises neste paciente, podendo ser uma opção de tratamento em outros pacientes com este tipo de epilepsia. / Background: Reflex epilepsy is a condition in which all seizures are triggered by a specific stimulus. There are many known stimulus, including defecation which has rarely been reported. In the majority of cases, it presents with refractory seizures. Objective: review the literature on reflex epilepsy, as well as identify defecation as a possible trigger and report a case of a patient with reflex seizures triggered by defecation documented by video-electroencephalogram monitoring. Methods: literature review on reflex epilepsies and review of medical records of a patient with reflex epilepsy triggered by defecation. Results: we present a 10-year-old-boy patient, left-handed, whose epilepsy onset was at the age of four. Its seizures were characterized by episodes of loss of consciousness and atonia during defecation. Video-electroencephalogram monitoring had shown a seizure triggered by defecation, characterized by right head deviation, left upper limb automatisms, associated with consciousness impairment and afterwards nose wiping with the left hand. The ictal EEG demonstrated theta rhythmic activity in the left temporal lobe. The brain magnetic resonance was normal. The interictal SPECT identified left anterior temporal lobe mild hypoperfusion. The patient became seizure free after the treatment with valproic acid and carbamazepine. Neuropsychological and quality of life assessments suggested global impairment, before and after seizure control. Conclusion: this is the third case of epilepsy induced by defecation, and the second with seizures documented by videoelectroencephalogram. Similar to this case, both had suggested lateralization and localization over the left temporal region, suggesting this region as a potential epileptogenic zone in patients with this type of reflex epilepsy. In our patient, the treatment with valproic acid and carbamazepine was effective for the seizure control and may be an option to other patients with this condition.
314

Uso do padrão ictal na epilepsia da região mesial do lobo temporal associada à esclerose hipocampal como marcador prognóstico pós-cirúrgico: uma coorte retrospectiva / The use of ictal patterns in mesial temporal lobe epilepsy with hippocampal sclerosis as a prognostic instrument for post-surgical seizures: a retrospective cohort study.

Monnerat, Bruno Zanotelli 29 March 2012 (has links)
Pacientes com epilepsia do lobo temporal farmacorresistente, frequentemente, possuem esclerose hipocampal como lesão epileptogênica. Muitas vezes, estes pacientes se beneficiam de lobectomia temporal para redução da ocorrência de crises epilépticas. Para que possam se submeter a este procedimento, é necessário o uso da videoeletroencefalografia prolongada para delimitação apurada da zona epileptogênica. Apesar dos avanços dos métodos diagnósticos nesta área, a busca por um instrumento que permita uma avaliação clara da chance de uma vida livre de crises após cirurgia permanece. No presente trabalho, a apresentação do padrão eletroencefalográfico ictal foi estudado, de forma a se pesquisar se existe relação entre a sua ocorrência e permanência em apenas um hemisfério cerebral com um melhor prognóstico pós-cirúrgico. Foram revisados os dados eletroencefalográficos ictais e os prontuários médicos de 284 pacientes. Procedeu-se à classificação de seus padrões eletroencefalográficos ictais em unilaterais ou bilaterais, e seu prognóstico após um, dois e cinco anos após cirurgia em livre de crise ou não livre de crise epiléptica. Apresentavam padrão unilateral 132 pacientes, e 152 apresentavam padrão bilateral. Estavam livres de crises 236 pacientes, e 48 ainda persistiam com crises epilépticas após cirurgia. Não houve associação entre padrões ictais unilaterais e uma vida livre de crises epilépticas após a cirurgia (diferença de 7,5%; p=0,092; chi-quadrado). Dessa forma, não se pode aplicar o padrão ictal eletroencefalográfico como ferramenta para predição de uma vida livre de crises após lobectomia temporal em pacientes com epilepsia da região mesial do lobo temporal associada à esclerose hipocampal. / Patients with drug-resistant temporal lobe epilepsy usually have hippocampal sclerosis as an epileptogenic lesion. Most of the times, these patients are benefited from temporal lobectomy for seizure relief. For this procedure to occur, a long-term videoelectroencephalogram is necessary for the accurate delineation of the epileptogenic zone. Despite the developments in the diagnostic methods on this area, the quest continues for an instrument that allows a clear evaluation of the chance to obtain a seizure-free life after epilepsy surgery. In the present study, the electroencephalographic ictal patterns were evaluated, and the relationship between its occurrence and permanence in one cerebral hemisphere and the possibility of a seizure-free outcome after surgery were compared. The ictal electroencephalografic and medical records of 284 patients were analyzed. A classification of ictal patterns, whether unilateral or bilateral, was issued, and the seizure outcome after one, two, and five years after surgery annotated. Unilateral ictal patterns occurred in 132 patients, and bilateral ictal patterns in 152. Seizure-free status was obtained in 236 patients, and 48 still persisted with seizures. There was no association between a unilateral ictal status and a seizure-free outcome after surgery (difference of 7.5%, p=0.092; chi-square). So, the electroencephalographic ictal pattern is not a valuable tool for predictions regarding seizure outcome in patients with mesial temporal lobe epilepsy associated with hippocampal sclerosis that are submitted to temporal lobectomy.
315

Avaliação do impacto da cirurgia de epilepsia no desenvolvimento de crianças com epilepsia refratária / Impact of epilepsy surgery on development of children with epilepsy refractory

Oliveira, Ana Valeria Duarte 03 March 2017 (has links)
A epilepsia é uma desordem cerebral definida por pelo menos duas crises não provocadas ocorrendo em um intervalo maior que 24 horas, uma crise não provocada e uma probabilidade de futuras crises similar ao risco de recorrência geral depois de duas crises não provocadas (pelo menos 60%) nos próximos 10 anos; ou o diagnóstico de uma síndrome epiléptica. Após o diagnóstico do tipo de epilepsia, existem situações em que o paciente não responde ao tratamento medicamentoso, apresentando pelo menos uma crise epiléptica por mês por um período mínimo de 2 anos. Se durante esse período, dois ou três diferentes fármacos antiepilépticos foram utilizados em monoterapia ou politerapia, e o paciente não obtém controle das crises, configura-se o quadro de epilepsia farmacorresistente. A intervenção cirúrgica é uma opção para essas crianças, atuando no controle das crises e, potencialmente no desenvolvimento neuropsicomotor. Neste estudo, avaliamos as variáveis clínicas como a idade de início da epilepsia, duração da epilepsia, frequência de crises, etiologia e a Escala de Comportamento Adaptativo de Vineland (ECAV) para caracterizar aspectos referentes aos domínios da comunicação, socialização, habilidades diárias e habilidades motoras, no período pré e pós-operatório de cirurgia de epilepsia. A nossa intenção foi determinar o impacto da cirurgia de epilepsia no desempenho dos pacientes nessas esferas avaliadas pela ECAV. Como resultados, encontramos que o grupo de participantes livre de crises após a cirurgia de epilepsia apresentou melhor desempenho cognitivo na segunda avaliação pós-operatória, quando comparado ao grupo que não teve controle de crises. A variável clínica duração da epilepsia influenciou a equivalência etária e as pontuações padrão da ECAV no período pré-operatório, sendo considerada determinante para o atraso neuropsicomotor dos pacientes submetidos à cirurgia de epilepsia. Quanto aos fatores preditivos de melhora das crises pós-operatórias, observou-se que Engel e cirurgia foram as variáveis consideradas significativas. A maioria dos pacientes (63,9%) na segunda avaliação pós-operatória ainda apresentou convulsões ou não obteve melhora. Nos achados da investigação sobre o impacto das crises em relação ao desenvolvimento neuropsicomotor na primeira avaliação 21,3 meses após a cirurgia, foi observado um ganho abaixo do esperado de apenas 4,4 meses na equivalência etária, não evidenciando melhora em curto prazo após a cirurgia, independente do controle de crises. Após 41,3 meses do procedimento cirúrgico os pacientes que apresentaram controle de crises tiveram ganhos adaptativos significativos de 15 meses na equivalência etária quando comparados com os que não apresentavam controle das crises. Nesses últimos pacientes, a equivalência etária permaneceu praticamente estável com um incremento de apenas 3 meses quando analisada as fases pré e pós - operatória / Epilepsy is a disease of the brain defined by at least two unprovoked seizures occurring 24 h apart, one unprovoked seizure and a probability of further seizures like the general recurrence risk (at least 60%) after two unprovoked seizures, occurring over the next 10 years or diagnosis of an epilepsy syndrome. After epilepsy diagnosis, there are situations where patients do not respond to drug treatment, developing one seizure per month for a minimum of 2 years. If during this period two or three antiepileptic drugs different used as monotherapy or in combination, a condition known as drug-resistant epilepsy. Epilepsy surgery is an option for children with drug-resistant epilepsy acting on the seizure control seizures and, potentially on neuropsychomotor development. In this study, we evaluated clinical variables such as epilepsy age of onset, epilepsy duration, seizure frequency, etiology and adaptive behavior scale of Vineland to characterize aspects related to age equivalence through the domains of communication, socialization, daily skills and motor skills pre- and post-surgical period. Our intention was to determine the impact of epilepsy surgery on the performance of patients in these areas evaluated by Vineland. Thus, we found that the seizure free group participants showed better cognitive performance in the second evaluation, compared to the group that not seizure controlled. The clinical variable duration of epilepsy influenced the age equivalence and standard Vineland scores in the preoperative period, being considered determinant for the neuropsychomotor delay of patients submitted to epilepsy surgery. Regarding the predictive factors of improvement of postoperative crises, it was observed that Engel and surgery were the variables considered significant. The majority of the patients (63.9%) in the second postoperative evaluation still had seizures or did not improve. The findings of the research on the impact of crises on neuropsychomotor were that in the first evaluation 21.3 months after surgery there was a below-expected gain of only 4.4 months of age equivalence, not showing improvement in the short term after surgery, independent of control crisis. After 41.3 months of the surgical procedure, the patients presenting with seizure control had significant adaptive gains of 15 months when compared to those without seizure control. In the latter patients, the age equivalence remained practically stable with an increase of o preoperative only 3 months, analyzing the phases pre and postoperative evaluation
316

What are parents' experiences of caring for their children with epilepsy? : a qualitative systematic review and thematic synthesis ; and, Mothers' experiences of being told about the risk of sudden unexpected death in epilepsy (SUDEP) for their child : an interpretative phenomenological analysis

Galliard, Helen January 2018 (has links)
Background: Parents of children with epilepsy have been shown to have higher rates of depression, anxiety and stress in comparison to parents of children without epilepsy due to the impact of caring for a child with a chronic condition. A systematic review of existing literature aimed to identify qualitative research that examined parents' experiences of caring for their children with epilepsy. Methods: The systematic review explored the experiences that parents have in caring for their child with epilepsy. A search of electronic databases for qualitative literature was completed. The quality of all eligible articles papers was assessed, and findings from studies were synthesised. Results: Twelve studies met inclusion criteria for the review; findings suggest that parents need time to process their child's diagnosis of epilepsy; they cope with this in differing ways and are motivated to learn how to adapt and cope with parenting their child with epilepsy. Conclusions: Parents of children with epilepsy may experience symptoms of stress, this may motivate them to learn how best to care for their child. Empirical Paper Abstract Background: Parents' experiences of being told about sudden unexpected death in epilepsy (SUDEP) may be particularly challenging to cope with. As little is known about how mothers understand and make sense of SUDEP, a qualitative research project aimed to explore mothers' experiences. It was hoped this would be helpful for clinicians to understand in order to assist them in providing information to parents in a way that minimises distress. Methods: The empirical article explored mother's experiences of being told about SUDEP and the subsequent impact of this for 11 mothers of children with epilepsy. Interpretative Phenomenological Analysis methodology was utilised, with themes derived from interpretation of interview transcripts, in order to describe the experiences of the participants. Results: Within the empirical study, five themes emerged. The way in which mothers found out about SUDEP seemed to have a link to their perception of risk and how they subsequently managed feelings of uncertainty and the psychological impact of knowing about SUDEP. Mothers' recommendations to clinicians included when, how and what to tell other parents, and were based on their own helpful and unhelpful experiences of being informed about SUDEP. Conclusions: In being told about SUDEP, mothers may struggle to make sense of it and this can be associated with an increase in anxiety. However, clinicians can reduce potential distress by carefully timing when and how they tell parents, and by making sure information is clear and relevant for the child in question.
317

ALTERATIONS IN GABAERGIC NTS NEURON FUNCTION IN ASSOCIATION WITH TLE AND SUDEP

Derera, Isabel Diane 01 January 2018 (has links)
Epilepsy is a neurological disorder that is characterized by aberrant electrical activity in the brain resulting in at least two unprovoked seizures over a period longer than 24 hours. Approximately 60% of individuals with epilepsy are diagnosed with temporal lobe epilepsy (TLE) and about one third of those individuals do not respond well to anti-seizure medications. This places those individuals at high risk for sudden unexpected death in epilepsy (SUDEP). SUDEP is defined as when an individual with epilepsy, who is otherwise healthy, dies suddenly and unexpectedly for unknown reasons. SUDEP is one of the leading causes of death in individuals with acquired epilepsies (i.e. not due to genetic mutations), such as TLE. Previous studies utilizing genetic models of epilepsy have suggested that circuitry within the vagal complex of the brainstem may play a role in SUDEP risk. Gamma-aminobutyric acid (GABA) neurons of the nucleus tractus solitarius (NTS) within the vagal complex receive, filter, and modulate cardiorespiratory information from the vagus nerve. GABAergic NTS neurons then project to cardiac vagal motor neurons, eventually effecting parasympathetic output to the periphery. In this study, a mouse model of TLE was used to assess the effect of epileptogenesis on GABAergic NTS neuron function and determine if functional alterations in these neurons impact SUDEP risk. It was discovered that mice with TLE (i.e. TLE mice) have significantly increased mortality rates compared to control animals, suggesting that SUDEP occurs in this model. Using whole cell electrophysiology synaptic and intrinsic properties of GABAergic NTS neurons were investigated in TLE and control mice. Results suggest that during epileptogenesis, GABAergic NTS neurons become hyperexcitable, potentially due to a reduction in A-type potassium channel current and increased excitatory synaptic input. Increases in hyperexcitability have been shown to be associated with an increased risk of spreading depolarization and action potential inactivation leading to neuronal quiescence. This may lead to a decreased inhibition of parasympathetic tone, causing cardiorespiratory collapse and SUDEP in TLE.
318

EARLY LIFE EXPERIENCES INFLUENCE SEIZURE SUSCEPTIBILITY OF 14-DAY OLD RAT PUPS IN A DAM-DEPENDENT AND SEX-DEPENDENT MANNER

Moriyama, Chikako 15 November 2012 (has links)
Epilepsy is a devastating disorder characterized by recurrent seizures. The pathophysiology of the disorder is not well understood. In this study the effects of early life, including pre- and post-natal, experiences on the seizure susceptibility of offspring was determined. Sprague-Dawley rats were air transported prior to breeding (In-House), on gestation day 9 (G9), or G16. The maternal behaviour was scored from P2-P13. On P14, seizure susceptibility of pups was assessed by randomly assigning the pups into Naïve (control), Saline, lipopolysaccharides (LPS; 200 ?g/kg), Kainic acid (KA; 1.75 mg/kg) or Febrile Convulsion (FC; LPS followed by KA) groups. No effect of prenatal transport was found on seizure susceptibility. Licking and grooming (LG) maternal behaviour was associated with higher FC seizure susceptibility of offspring. Male pups were more susceptible to FC seizure than female pups. These results emphasize the dam-dependent and sex-dependent effects of early life experiences on seizure susceptibility of offspring.
319

Newer antiepileptic drugs in women of child-bearing age : pharmacokinetic studies during pregnancy, breastfeeding, and contraception /

Öhman, Inger, January 2006 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 6 uppsatser.
320

A study of some personality characteristics of epileptics

Arluck, Edward Wiltcher, January 1941 (has links)
Issued also as Thesis (Ph. D.)--Columbia University. / Bibliography: p. 75-77.

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