المؤلفون: Christiaen, Emma, Goossens, Marie Gabrielle, Descamps, Benedicte, Larsen, Lars E, Boon, P Paul, Raedt, Robrecht, Vanhove, Christian

المصدر: ISSN:0969-9961.

الوصف: Epilepsy is a neurological disorder characterized by recurrent epileptic seizures. The involvement of abnormal functional brain networks in the development of epilepsy and its comorbidities has been demonstrated by electrophysiological and neuroimaging studies in patients with epilepsy. This longitudinal study investigated changes in dynamic functional connectivity (dFC) and network topology during the development of epilepsy using the intraperitoneal kainic acid (IPKA) rat model of temporal lobe epilepsy (TLE). Resting state functional magnetic resonance images (rsfMRI) of 20 IPKA animals and 7 healthy control animals were acquired before and 1, 3, 6, 10 and 16 weeks after status epilepticus (SE) under medetomidine anaesthesia using a 7 T MRI system. Starting from 17 weeks post-SE, hippocampal EEG was recorded to determine the mean daily seizure frequency of each animal. Dynamic FC was assessed by calculating the correlation matrices between fMRI time series of predefined regions of interest within a sliding window of 50 s using a step length of 2 s. The matrices were classified into 6 FC states, each characterized by a correlation matrix, using k-means clustering. In addition, several time-variable graph theoretical network metrics were calculated from the time-varying correlation matrices and classified into 6 states of functional network topology, each characterized by a combination of network metrics. Our results showed that FC states with a lower mean functional connectivity, lower segregation and integration occurred more often in IPKA animals compared to control animals. Functional connectivity also became less variable during epileptogenesis. In addition, average daily seizure frequency was positively correlated with percentage dwell time (i.e. how often a state occurs) in states with high mean functional connectivity, high segregation and integration, and with the number of transitions between states, while negatively correlated with percentage dwell time in states with a low mean functional ...

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العلاقة: http://repository.tue.nl/918971Test

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المؤلفون: Christiaen, Emma, Goossens, Marie Gabrielle, Raedt, Robrecht, Descamps, Benedicte, Larsen, Lars E, Craey, Erine, Carrette, Evelien, Vonck, KEJ, Boon, P Paul, Vanhove, Christian

المصدر: ISSN:1053-8119.

الوصف: Epilepsy is a neurological disorder characterized by recurrent epileptic seizures. Electrophysiological and neuroimaging studies in patients with epilepsy suggest that abnormal functional brain networks play a role in the development of epilepsy, i.e. epileptogenesis, resulting in the generation of spontaneous seizures and cognitive impairment. In this longitudinal study, we investigated changes in functional brain networks during epileptogenesis in the intraperitoneal kainic acid (IPKA) rat model of temporal lobe epilepsy (TLE) using resting state functional magnetic resonance imaging (rsfMRI) and graph theory. Additionally, we investigated whether these changes are related to the frequency of occurrence of spontaneous epileptic seizures in the chronic phase of epilepsy. Using a 7T MRI system, rsfMRI images were acquired under medetomidine anaesthesia before and 1, 3, 6, 10 and 16 weeks after status epilepticus (SE) induction in 20 IPKA animals and 7 healthy control animals. To obtain a functional network, correlation between fMRI time series of 38 regions of interest (ROIs) was calculated. Then, several graph theoretical network measures were calculated to describe and quantify the network changes. At least 17 weeks post-SE, IPKA animals were implanted with electrodes in the left and right dorsal hippocampus, EEG was measured for 7 consecutive days and spontaneous seizures were counted. Our results show that correlation coefficients of fMRI time series shift to lower values during epileptogenesis, indicating weaker whole brain network connections. Segregation and integration in the functional brain network also decrease, indicating a lower local interconnectivity and a lower overall communication efficiency. Secondly, this study demonstrates that the largest decrease in functional connectivity is observed for the retrosplenial cortex. Finally, post-SE changes in functional connectivity, segregation and integration are correlated with seizure frequency in the IPKA rat model.

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العلاقة: http://repository.tue.nl/918977Test

الإتاحة: http://repository.tue.nl/918977Test

المؤلفون: Khachatryan, Elvira, Wittevrongel, Benjamin, Fahimi Hnazaee, Mansoureh, Carrette, Evelien, Dauwe, Ine, Meurs, Alfred, Boon, P Paul, van Roost, Dirk, Van Hulle, Marc M

المصدر: ISSN:1053-8119.

الوصف: Facilitation of object processing in the brain due to a related context (priming) can be influenced by both semantic connections and perceptual similarity. It is thus important to discern these two when evaluating the spatio-temporal dynamics of primed object processing. The repetition-priming paradigm frequently used to study perceptual priming is, however, unable to differentiate between the mentioned priming effects, possibly leading to confounded results. In the current study, we recorded brain signals from the scalp and cerebral convexity of nine patients with refractory epilepsy in response to related and unrelated image-pairs, all of which shared perceptual features while only related ones had a semantic connection. While previous studies employing a repetition-priming paradigm observed largely overlapping networks between semantic and perceptual priming effects, our results suggest that this overlap is only partial (both temporally and spatially). These findings stress the importance of controlling for perceptual features when studying semantic priming.

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العلاقة: http://repository.tue.nl/918969Test

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المؤلفون: Martos Martinez-Caja, Ana, De Herdt, V, Boon, P Paul, Brandl, Ulrich, Cock, Hannah, Parra, Jaime, Perucca, Emilio, Thadani, Vijay, Moons, Christel Palmyre Henri

المصدر: ISSN:1525-5050.

الوصف: Introduction: The unpredictability of epileptic seizures is considered an important threat to the quality of life of a person with epilepsy. Currently, however, there are no tools for seizure prediction that can be applied to the domestic setting. Although the information about seizure-alert dogs – dogs that display changes in behavior before a seizure that are interpreted by the owner as an alert – is mostly anecdotal; living with an alerting dog (AD) has been reported to improve quality of life of the owner by reducing the stress originating from the unpredictability of epileptic seizures and, sometimes, diminishing the seizure frequency. Aim of the study: The aim of the study was to investigate, at an international level, the behaviors displayed by trained and untrained dogs that are able to anticipate seizures and to identify patient- and dog-related factors associated with the presence or absence of alerting behavior. Methodology: An online questionnaire for dog owners with seizures was designed. Information about the participants (demographics, seizure type, presence of preictal symptoms) and their dogs (demographics, behavior around the time of seizures) was collected. In addition, two validated scales were included to measure the human–dog relationship (Monash Dog–Owner Relationship scale (MDORS)) and five different traits of the dogs' personality (Monash Canine Personality Questionnaire refined (MCPQ-R)). Results: Two hundred and twenty-seven responses of people experiencing seizures were received from six participant countries: 132 from people with dogs that had started alerting spontaneously, 10 from owners of trained AD, and the rest from owners of dogs that did not display any alerting behavior (nonalerting dog (NAD)). Individuals' gender, age, or seizure type did not predict the presence of alerting behavior in their dogs. People who indicated that they experience preictal symptoms were more likely to have a spontaneously AD. The owner–dog bond was significantly higher with ADs compared with NADs, ...

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العلاقة: http://repository.tue.nl/918992Test

الإتاحة: http://repository.tue.nl/918992Test

المؤلفون: Mesraoua, Boulenouar, Deleu, Dirk, Kullmann, Dimitri M, Shetty, Ashok K, Boon, P Paul, Perucca, Emilio, Mikati, Mohamad A, Asadi-Pooya, Ali A

المصدر: ISSN:1525-5050.

الوصف: Despite the availability of many antiepileptic drugs (AEDs) (old and newly developed) and, as recently suggested, their optimization in the treatment of patients with uncontrolled seizures, more than 30% of patients with epilepsy continue to experience seizures and have drug-resistant epilepsy; the management of these patients represents a real challenge for epileptologists and researchers. Resective surgery with the best rates of seizure control is not an option for all of them; therefore, research and discovery of new methods of treating resistant epilepsy are of extreme importance. In this article, we will discuss some innovative approaches, such as P-glycoprotein (P-gp) inhibitors, gene therapy, stem cell therapy, traditional and novel antiepileptic devices, precision medicine, as well as therapeutic advances in epileptic encephalopathy in children; these treatment modalities open up new horizons for the treatment of patients with drug-resistant epilepsy.

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العلاقة: http://repository.tue.nl/918987Test

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المؤلفون: Monté, Carlos Paul, Monté, Carlos Jules, Boon, P Paul, Arends, JBAM Johan

المصدر: ISSN:1525-5050.

الوصف: Introduction: Heart rate decrease during epileptic seizures is rare and should be considered in patients with unusual or refractory episodes of syncope or in patients with a history suggestive of both epilepsy and syncope. We systematically reviewed the literature to better understand the clinical signs and risk factors of ictal heart rate decreases. Material and methods: We performed a literature-search on “ictal bradycardia” and “ictal asystole” in Pubmed and added papers from the references and personal archives. Articles relating to animal studies, seizures without ictal decrease of heart rate, cases without simultaneous electroencephalography (EEG) and electrocardiography (ECG), convulsive syncopes, or cases with bradycardia before seizure onset and articles written in other languages than English, Dutch, German, French, or Spanish were excluded. Full texts of the remaining articles were screened for cases of ictal bradycardia or ictal asystole. Cases were selected on the basis of a self-designed quality score. The relationship of RR wave interval of at least 5 s, signs of syncope, and EEG signs of ischemia were analyzed with chi-square test and identifying 95% confidence intervals. Results: Ictal bradycardia and ictal asystole predominantly occurred during focal seizures with loss of awareness (proportion in the combined group of bradycardia and asystole (p1 + 2) = 0.85) in people with mainly left lateralized (p1 + 2 = 0.64; p = 0.001) temporal lobe seizures (p1 + 2 = 0.91). Seizures with ictal asystole typically started with a heart rate decrease. During ictal asystole in the majority of cases, not only the clinical signs of syncope occurred (change of proportion (Δp) = 0.67; 95% CI: 0.48–0.86; p < 0.0001), i.e., interrupting the seizure semiology, but also the characteristic EEG signs of ischemia (Δp = 0.50; 95% CI: 0.26–0.74; p < 0.001). We found a statistically significant relation between signs of syncope and EEG signs of ischemia (Δp = − 0.37; 95% CI: (− 0.64)–(− 0.10); p < 0.01) but not ...

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العلاقة: http://repository.tue.nl/908165Test

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المؤلفون: Kruijs, SJM van der, Vonck, KEJ, Langereis, GR Geert, Feijs, LMG Loe, Bodde, NMG, Lazeron, RHC, Carrette, ECB, Boon, P Paul, Backes, W Walter, Jansen, JFA Jaap, Aldenkamp, AP Albert, Cluitmans, PJM Pierre

المصدر: ISSN:1525-5050.

الوصف: Objective: Psychogenic nonepileptic seizures (PNESs) resemble epileptic seizures but originate from psychogenic rather than organic causes. Patients with PNESs are often unable or unwilling to reflect on underlying emotions. To gain more insight into the internal states of patients during PNES episodes, this study explored the time course of heart rate variability (HRV) measures, which provide information about autonomic nervous system functioning and arousal. Methods: Heart rate variability measures were extracted from double-lead electrocardiography data collected during 1-7. days of video-electroencephalography monitoring of 20 patients with PNESs, in whom a total number of 118 PNESs was recorded. Heart rate (HR) and HRV measures in time and frequency domains (standard deviation of average beat-to-beat intervals (SDANN), root mean square of successive differences (RMSSD), high-frequency (HF) power, low-frequency (LF) power, and very low-frequency (VLF) power) were averaged over consecutive five-minute intervals. Additionally, quantitative analyses of Poincaré plot parameters (SD1, SD2, and SD1/SD2 ratio) were performed. Results: In the five-minute interval before PNES, HR significantly (p <0.05) increased (d = 2.5), whereas SDANN (d = - 0.03) and VLF power (d = - 0.05) significantly decreased. During PNES, significant increases in HF power (d = 0.0006), SD1 (d = 0.031), and SD2 (d = 0.016) were observed. In the five-minute interval immediately following PNES, SDANN (d = 0.046) and VLF power (d = 0.073) significantly increased, and HR (d = - 5.1) and SD1/SD2 ratio (d = - 0.14) decreased, compared to the interval preceding PNES. Conclusion: The results suggest that PNES episodes are preceded by increased sympathetic functioning, which is followed by an increase in parasympathetic functioning during and after PNES. Future research needs to identify the exact nature of the increased arousal that precedes PNES.

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العلاقة: http://repository.tue.nl/889111Test

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المؤلفون: Bodde, NMG, Kruijs, SJM van der, IJff, Dominique M, Lazeron, RHC, Vonck, KEJ, Boon, P Paul, Aldenkamp, AP Albert

المصدر: ISSN:1525-5050.

الوصف: Introduction In this open non-controlled clinical cohort study, the applicability of a theoretical model for the diagnosis of psychogenic non-epileptic seizures (PNES) was studied in order to define a general psychological profile and to specify possible subgroups. Methods Forty PNES patients were assessed with a PNES "test battery" consisting of eleven psychological instruments, e.g., a trauma checklist, the global cognitive level, mental flexibility, speed of information processing, personality factors, dissociation, daily hassles and stress and coping factors. Results The total PNES group was characterized by multiple trauma, personality vulnerability (in a lesser extent, neuropsychological vulnerabilities), no increased dissociation, many complaints about daily hassles that may trigger seizures and negative coping strategies that may contribute to prolongation of the seizures. Using factor analysis, specific subgroups were revealed: a ‘psychotrauma subgroup’, a ‘high vulnerability somatizing subgroup’ (with high and low cognitive levels) and a ‘high vulnerability sensitive personality problem subgroup’. Conclusion Using a theoretical model in PNES diagnosis, PNES seem to be a symptom of distinct underlying etiological factors with different accents in the model. Hence, describing a general profile seems to conceal specific subgroups with subsequent treatment implications. This study identified three factors, representing two dimensions of the model, that are essential for subgroup classification: psychological etiology (psychotrauma or not), vulnerability, e.g., the somatization tendency, and sensitive personality problems/characteristics (‘novelty seeking’). For treatment, this means that interventions could be tailored to the main underlying etiological problem. Also, further research could focus on differentiating subgroups with subsequent treatment indications and possible different prognoses.

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العلاقة: http://repository.tue.nl/769926Test

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المؤلفون: Bodde, NMG, Bartelet, Dimona C J, Ploegmakers, Maria, Lazeron, RHC, Aldenkamp, AP Albert, Boon, P Paul

المصدر: ISSN:1525-5050.

الوصف: This comparative study explored whether psychogenic nonepileptic seizures (PNES) are a unique disorder with distinctive personality characteristics or (seen from the personality profile) PNES are allied with the domain of a general functional somatic symptom and syndrome (FSSS). We compared the Minnesota Multiphasic Personality Inventory 2 (MMPI-2) results for 41 patients with newly diagnosed PNES and 43 patients with newly diagnosed insomnia. There were no statistically significant quantitative scoring differences on the main clinical scales, indicating that there is no substantial difference in "personality makeup" between the two groups with a FSSS. Additional subscale analysis indicated that patients with PNES reported significantly more somatic complaints (Hysteria 4) and bizarre sensory experiences (Schizophrenia 6). Further profile analysis revealed that the personality pattern of patients with PNES was characterized by a strong tendency toward "conversion V, a lack of control pattern and less excessive worries" as compared with patients with insomnia. Patients with PNES are characterized by a stronger tendency toward somatization and externalization, which has treatment implications.

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العلاقة: http://repository.tue.nl/882033Test

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