10 research outputs found

    Connecting the dots : functional networks and cognition in chronic epilepsy

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    Mortality after primary intracerebral hemorrhage in relation to post-stroke seizures

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    Contains fulltext : 182353.pdf (publisher's version ) (Open Access)Seizures after intracerebral hemorrhage are repeatedly seen. Whether the development of seizures after intracerebral hemorrhage affects survival in the long term is unknown. This study aims to determine the relation between seizures (i.e., with and without anti-epileptic therapy) and long-term mortality risk in a large patient population with intracerebral hemorrhage. We retrospectively included patients with a non-traumatic ICH in all three hospitals in the South Limburg region in the Netherlands between January 1st 2004 and December 31st 2009, and we assessed all-cause mortality until March 14th 2016. Patient who did not survive the first seven days after intracerebral hemorrhage were excluded from analyses. We used Cox multivariate analyses to determine independent predictors of mortality. Of 1214 patients, 783 hemorrhagic stroke patients fulfilled the inclusion criteria, amongst whom 37 (4.7%) patients developed early seizures (within 7 days after hemorrhage) and 77 (9.8%) developed late seizures (more than 7 days after hemorrhage). Seizure development was not significantly related to mortality risk after correction for conventional vascular risk factors and hemorrhage severity. However, we found a small but independent relation between the use of anti-epileptic drugs and a lower long-term mortality (HR = 0.32, 95% CI 0.11-0.91). In our large population, seizures and epilepsy did not relate independently to an increased mortality risk after hemorrhage

    Abnormal profiles of local functional connectivity proximal to focal cortical dysplasias

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    INTRODUCTION: Focal cortical dysplasia (FCD) is a congenital malformation of cortical development that often leads to medically refractory epilepsy. Focal resection can be an effective treatment, but is challenging as the surgically relevant abnormality may exceed the MR-visible lesion. The aim of the current study is to develop methodology to characterize the profile of functional connectivity around FCDs using resting-state functional MRI and in the individual patient. The detection of aberrant connectivity may provide a means to more completely delineate the clinically relevant lesion. MATERIALS AND METHODS: Fifteen FCD patients (age, mean±SD: 31±11 years; 11 males) and 16 matched healthy controls (35±9 years; 7 males) underwent structural and functional imaging at 3 Tesla. The cortical surface was reconstructed from the T1-weighted scan and the registered functional MRI data was spatially normalized to a common anatomical standard space employing the gyral pattern. Seed-based functional connectivity was determined in all subjects for all dysplasia locations. A single patient was excluded based on an aberrant FCD seed time series. Functional connectivity as a function of geodesic distance (along the cortical surface) was compared between the individual patients and the homotopic normative connectivity profiles derived from the controls. RESULTS: In 12/14 patients, aberrant profiles of functional connectivity were found, which demonstrated both hyper- and hypoconnectivity as well as combinations. Abnormal functional connectivity was typically found (also) beyond the lesion visible on structural MRI, while functional connectivity profiles not related to a lesion appeared normal in patients. CONCLUSION: This novel functional MRI technique has potential for delineating functionally aberrant from normal cortex beyond the structural lesion in FCD, which remains to be confirmed in future research

    Metabolic and functional MR biomarkers of antiepileptic drug effectiveness: a review

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    As a large number of patients with epilepsy do not respond favorably to antiepileptic drugs (AEDs), a better understanding of treatment failure and the cause of adverse side effects is required. The working mechanisms of AEDs also alter neurotransmitter concentrations and brain activity, which can be measured using MR spectroscopy and functional MR imaging, respectively. This review presents an overview of clinical research of MR spectroscopy and functional MR imaging studies to the effects of AEDs on the brain. Despite the scarcity of studies associating MR findings to the effectiveness of AEDs, the current research shows clear potential regarding this matter. Several GABAergic AEDs have been shown to increase the GABA concentration, which was related to seizure reductions, while language problems due to topiramate have been associated with altered activation patterns measured with functional MR imaging. MR spectroscopy and functional MR imaging provide biomarkers that may predict individual treatment outcomes, and enable the assessment of mechanisms of treatment failure and cognitive side effects

    Deterioration of dyslexia after non-dominant temporal lobectomy for drug-resistant epilepsy

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    Item does not contain fulltextWe present a patient with drug-resistant right-sided temporal lobe epilepsy, caused by a ganglioglioma of the parahippocampal gyrus. Preoperatively, the patient was also known to have dyslexia. A right-sided anterior temporal lobectomy, including complete lesionectomy, was performed. Several months after the otherwise uncomplicated procedure, the patient complained about visual memory disturbances, accompanied by increased reading and spelling problems. Postoperative neuropsychological examination revealed deterioration of the visual memory functions, compared to the preoperative assessment, and consequently provided a possible explanation for worsening of the pre-existing dyslexia. In this case report, we hypothesize on the cause of this unusual deterioration and present recommendations to be included in the preoperative epilepsy surgery evaluation for patients with verbal or reading disorders such as dyslexia.6 p

    Predictive value of functional MRI and EEG in epilepsy diagnosis after a first seizure

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    It is often difficult to predict seizure recurrence in subjects who have suffered a first-ever epileptic seizure. In this study, the predictive value of physiological signals measured using Electroencephalography (EEG) and functional MRI (fMRI) is assessed. In particular those patients developing epilepsy (i.e. a second unprovoked seizure) that were initially evaluated as having a low risk of seizure recurrence are of interest.In total, 26 epilepsy patients, of which 8 were initially evaluated as having a low risk of seizure recurrence (i.e. converters), and 17 subjects with only a single seizure were included. All subjects underwent routine EEG as well as fMRI measurements. For diagnostic classification, features related to the temporal dynamics were determined for both the processed EEG and fMRI data. Subsequently, a logistic regression classifier was trained on epilepsy and first-seizure subjects. The trained model was tested using the clinically relevant converters group.The sensitivity, specificity, and AUC (mean +/- SD) of the regression model including metrics from both modalities were 74 +/- 19%, 82 +/- 18%, and 0.75 +/- 0.12, respectively. Positive and negative predictive values (mean SD) of the regression model with both EEG and fMRI features are 84 +/- 14% and 78 +/- 12%. Moreover, this EEG/fMRI model showed significant improvements compared to the clinical diagnosis, whereas the models using metrics from either EEG or fMRI do not reach significance (p > 0.05).Temporal metrics computationally derived from EEG and fMRI time signals may clinically aid and synergistically improve the predictive value in a first-seizure sample. (C) 2020 The Author(s). Published by Elsevier Inc

    Predictive value of functional MRI and EEG in epilepsy diagnosis after a first seizure

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    It is often difficult to predict seizure recurrence in subjects who have suffered a first-ever epileptic seizure. In this study, the predictive value of physiological signals measured using Electroencephalography (EEG) and functional MRI (fMRI) is assessed. In particular those patients developing epilepsy (i.e. a second unprovoked seizure) that were initially evaluated as having a low risk of seizure recurrence are of interest.In total, 26 epilepsy patients, of which 8 were initially evaluated as having a low risk of seizure recurrence (i.e. converters), and 17 subjects with only a single seizure were included. All subjects underwent routine EEG as well as fMRI measurements. For diagnostic classification, features related to the temporal dynamics were determined for both the processed EEG and fMRI data. Subsequently, a logistic regression classifier was trained on epilepsy and first-seizure subjects. The trained model was tested using the clinically relevant converters group.The sensitivity, specificity, and AUC (mean +/- SD) of the regression model including metrics from both modalities were 74 +/- 19%, 82 +/- 18%, and 0.75 +/- 0.12, respectively. Positive and negative predictive values (mean SD) of the regression model with both EEG and fMRI features are 84 +/- 14% and 78 +/- 12%. Moreover, this EEG/fMRI model showed significant improvements compared to the clinical diagnosis, whereas the models using metrics from either EEG or fMRI do not reach significance (p > 0.05).Temporal metrics computationally derived from EEG and fMRI time signals may clinically aid and synergistically improve the predictive value in a first-seizure sample. (C) 2020 The Author(s). Published by Elsevier Inc

    Societal costs and quality of life analysis in patients undergoing resective epilepsy surgery: A one-year follow-up

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    Although effectiveness of Resective Epilepsy Surgery (RES) for patients with drug-resistant epilepsy (DRE) is widely proven, research on the impact of societal costs (SC) is lacking. The aim of this study is to provide both clinical and economic outcomes of RES by offering an overview of treatment effectiveness as well as SC of RES in a cohort of 30 Dutch DRE patients. This project serves as a pilot project to offer an up-to-date model for larger cost-effectiveness studies. Medical consumption, productivity losses, disease-specific and generic health-related quality of life (QoL), and seizure frequency were assessed before and 3-, 6-, and 12-months post-surgery with validated questionnaires. Linear mixed models, ANOVAs, and logistic regressions were performed. SC for the first year after RES entailed €54,376 and decreased over time. Moreover, 50% of patients experienced a clinically important increase in disease-specific QoL and 53% of patients in generic health-related QoL. Lastly, 73% of patients reached seizure freedom 12 months postoperative. Seizure reduction was correlated with increase in disease-specific QoL. Within one year after surgery, RES leads to reduction in SC and improvements in QoL over time. Future research should encompass longer follow-up periods, larger sample size, and a cost-effectiveness analysis with a comparator

    Histopathological findings in brain tissue obtained during epilepsy surgery

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    Item does not contain fulltextBackground: Detailed neuropathological information on the structural brain lesions underlying seizures is valuable for understanding drug-resistant focal epilepsy. Methods: We report the diagnoses made on the basis of resected brain specimens from 9523 patients who underwent epilepsy surgery for drug-resistant seizures in 36 centers from 12 European countries over 25 years. Histopathological diagnoses were determined through examination of the specimens in local hospitals (41%) or at the German Neuropathology Reference Center for Epilepsy Surgery (59%). Results: The onset of seizures occurred before 18 years of age in 75.9% of patients overall, and 72.5% of the patients underwent surgery as adults. The mean duration of epilepsy before surgical resection was 20.1 years among adults and 5.3 years among children. The temporal lobe was involved in 71.9% of operations. There were 36 histopathological diagnoses in seven major disease categories. The most common categories were hippocampal sclerosis, found in 36.4% of the patients (88.7% of cases were in adults), tumors (mainly ganglioglioma) in 23.6%, and malformations of cortical development in 19.8% (focal cortical dysplasia was the most common type, 52.7% of cases of which were in children). No histopathological diagnosis could be established for 7.7% of the patients. Conclusions: In patients with drug-resistant focal epilepsy requiring surgery, hippocampal sclerosis was the most common histopathological diagnosis among adults, and focal cortical dysplasia was the most common diagnosis among children. Tumors were the second most common lesion in both groups. (Funded by the European Union and others.)9 p
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