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Query: UMLS:C0014547 (focal epilepsy)
 1,627 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epilepsy is the most common neurological disease. Depending on the site of the origin of seizures epilepsy may be divided into the focal and generalised forms. Partial epilepsy most often occurs in the drug-resistant form, the most frequent variant of which is temporal lobe epilepsy--TLE. In the case of focal lesions the removal of the area responsible for the origin of seizures may result in good therapeutic outcome. It is, therefore, necessary to precisely localise an epileptogenic focus. This may be achieved using neuropsychological tests, electroencephalography (EEG), magnetic resonance imaging (MRI), positron emission tomography (PET), single photon emission computed tomography (SPECT), functional magnetic resonance imaging (fMRI), magnetic resonance spectroscopy (MRS) and diffusion magnetic resonance imaging (dMRI). There is a considerable group of patients in whom the cause of the disease is a subtle structural lesion that could not be found using CT or MRI, or a functional cause. In such cases novel techniques are used that show functional causes, e.g. the change in blood perfusion, cellular components concentration or neurotransmitter binding. Those techniques involve: functional MR, PET, SPECT, dMR and MRS. Due to the limitations of other methods magnetic resonance spectroscopy has played an increasing role in the imaging diagnostics of epilepsy. MRS is a non-invasive method of the assessment of the chemical composition of a tissue sample. In persons with epilepsy HMRS of the hippocampus may show the changes in specific metabolites. Several studies have also shown that HMRS is a useful non-invasive method of monitoring the response to anti-epileptic drugs.
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PMID:[The role of the magnetic resonance spectroscopy in the diagnosis of temporal lobe epilepsy]. 1840 12

More than half of patients with newly diagnosed epilepsy achieve complete seizure control without major side-effects. Patients who continue to have seizures after initial medical therapy should have an early and detailed assessment to confirm the diagnosis, to determine the underlying cause and epilepsy syndrome, and to choose an adequate treatment strategy. The risks and potential benefits of surgical procedures or experimental therapy have to be weighed against the chance of improvement and the potential side-effects of additional medical therapy. Surgery for temporal lobe epilepsy, the most common cause of focal epilepsy, can control seizures and improve quality of life in appropriately selected patients. However, around 20-30% of patients do not respond to medical or surgical treatment. The management of chronic intractable epilepsy requires comprehensive care to address the adverse events of medical treatment, quality of life issues, and comorbid disorders. Much research focuses on the experimental treatment options that offer hope of seizure reduction or cure.
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PMID:Intractable epilepsy: management and therapeutic alternatives. 1848 15

Imaging changes in patients with focal epilepsy are not only seen in areas where seizures arise but often also in remote locations. The mechanism for such changes is unknown. We aimed to investigate whether patients with temporal lobe epilepsy (TLE) have microstructural changes involving the posterior portion of the corpus callosum (CC), where it links the temporal lobes, using presurgical diffusion tensor imaging (DTI) sequences. Ten patients with medically intractable TLE (two mesial TLE, eight neocortical TLE) who had seizure-free surgical outcomes were compared with 10 healthy controls. The regions of interest were outlined at each Witelson region (WR). Fractional anisotropy (FA), apparent diffusion coefficient (ADC) and three principal diffusivity values (lambda1, lambda2, lambda3) were determined in each WR. We performed tractography originating at each WR. In the TLE patients, the FA values were lower at the splenium of the corpus callosum (WR 7) compared to controls (p<0.05). Analysis of Eigen values in that location revealed that lambda1 values were decreased while lambda2 and lambda3 values were increased (p<0.05). Tractography revealed the connection between both temporal lobes via WR 7. In conclusion, decreased FA values with decreased lambda1 and increased lambda2 and lambda3 at the splenium of CC suggest that the pathologic changes, Wallerian degeneration, extend to the corpus callosum in TLE patients. Seizure-induced damage may cause secondary white matter degeneration along the tapetum and through the splenium of the corpus callosum, a potential pathway of spread in temporal lobe seizures.
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PMID:Secondary white matter degeneration of the corpus callosum in patients with intractable temporal lobe epilepsy: a diffusion tensor imaging study. 1857 87

Seventy-nine consecutive inpatients of an epilepsy center (34 women, 45 men) who had either generalized epilepsy, temporal lobe epilepsy, focal epilepsy of other origin, or no epilepsy completed the Derogatis Interview for Sexual Function-Self-Report Inventory. Quantitative assessments of blood levels were performed for prolactin, total testosterone, sex hormone-binding globulin, estradiol, dehydroepiandrosterone sulfate, luteinizing hormone, and follicle-stimulating hormone. In men, increasing sex hormone-binding globulin levels and duration of epilepsy decreased sexual quality of life. Sex hormone-binding globulin level in men was related to enzyme-inducing antiepileptic drugs and age. In women, we found no associations between blood hormone levels and sexual quality of life. Our results suggest that sexual quality of life is affected by sexual hormone blood levels in men, but not in women with epilepsy. Avoiding enzyme-inducing antiepileptic drugs may lower the risk of raised sex hormone-binding globulin levels and, thus, of lowered sexual quality of life in men with epilepsy.
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PMID:Sexual quality of life in epilepsy: correlations with sex hormone blood levels. 1899 45

Extratemporal epileptic foci are increasingly treated successfully with surgery. This study assesses the effect of extratemporal epilepsy surgery on the subjective handicaps of epilepsy patients. Twenty-one adults with pharmacoresistant focal epilepsy undergoing extratemporal surgical interventions were analyzed compared to an age-, gender-, and IQ-matched patient group with temporal lobe epilepsy. A questionnaire on subjective handicaps was given prior to surgery and after 1 year of follow-up. There were significant postoperative improvements in the domains of work and activities, self perception, and judgement of changes in handicap. These changes were similar to those in patients undergoing temporal lobe surgery and not restricted to those achieving complete seizure remission. Epilepsy surgery thus improves not only seizure control but also quality of life in patients with extratemporal focus localization.
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PMID:[Quality of life following extratemporal epilepsy surgery]. 1922 9

Previous studies have reported activation of inflammatory cytokines in seizures, but clinical characteristics of epilepsy associated with cytokine activation have not been well established. In this study, serum levels of interleukin-6 (IL-6) and interleukin-1 receptor antagonist (IL-1RA) were measured, and clinical characteristics of epilepsy were assessed in 86 well-evaluated patients with refractory focal epilepsy and in 5 patients with controlled focal epilepsy. Epilepsy was evaluated based on patient histories, electroclinical findings, and high-resolution brain MRI scans. Sixty-three healthy blood donors served as controls. IL-6 concentrations were chronically increased in epilepsy patients (11%) compared with healthy controls (0%) (P = 0.007). Increased levels of IL-6 were more prevalent in patients with temporal lobe epilepsy (TLE) compared to patients with extra-TLE (P = 0.028). Also the mean and the median serum levels of IL-6 were higher in patients with TLE than in patients with extra-TLE (P = 0.042). Concentrations of IL-1RA were not significantly different in patients compared with controls. Indicated by increased levels of IL-6 in TLE, epilepsy type is important in determining chronic overproduction of cytokines in refractory focal epilepsy. The results may reflect a chronic immunological process in the brain in patients with refractory epilepsy.
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PMID:Interleukin-6 levels are increased in temporal lobe epilepsy but not in extra-temporal lobe epilepsy. 1925 6

Temporal lobe epilepsy with hippocampus sclerosis (HS) is the most frequent focal epilepsy and often refractory to anticonvulsant therapy. Secondary structural damage has been reported in several studies of temporal lobe epilepsy and unilateral hippocampal sclerosis. Applying diffusion tensor imaging (DTI) we investigated alterations in white matter following temporal lobe surgery in patients with medial temporal lobe epilepsy. We examined 40 patients who underwent surgery at our hospital for HS between 1996 and 2006 with diffusion tensor imaging (DTI). Images were obtained at a 3 T MRI scanner employing 60 gradient directions. Tract-based spatial statistics (TBSS), a novel voxel-based approach, was applied to analyze the data. Both patients with left- as well as right-sided surgery exhibited widespread degradation of fractional anisotropy (FA) in main fiber tracts not limited to the respective temporal lobe such as the uncinate fasciculus, the fronto-occipital fasciculus, the superior longitudinal fasciculus, the corpus callosum and the corticospinal tract on the respective hemisphere. Patients with left-hemispheric surgery showed more widespread affections ipsilaterally and also FA decrease in the contralateral inferior longitudinal fasciculus. DTI demonstrates widespread clusters of abnormal diffusivity and anisotropy in prominent white matter tracts linking mesial temporal lobe structures with other brain areas. Alterations in the ipsilateral mesial temporal lobe can be attributed to be a result of surgery, whereas extratemporal FA decrease is more likely the result of the underlying seizure disorder.
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PMID:Widespread affections of large fiber tracts in postoperative temporal lobe epilepsy. 1928 70

Described here is a case of a patient who made the sign of the cross during right mesial temporal seizures, documented by intracranial depth electrode and simultaneous scalp video-EEG. The patient was ultimately found to have predominantly left temporal lobe epilepsy, and she was rendered seizure free for many years following a left anterior temporal lobe resection. Most interestingly, however, was a suggestion that in her case, making the sign of the cross may have represented a learned ictal behavioral phenomenon: the patient had been forced, over a period of many years, to make this gesture as an atonement in the postictal period. The movement ultimately came to be performed unconsciously, during the ictus, associated with a lateralized seizure discharge in the right temporal lobe. In contrast to seizure-induced experiential phenomena and typical motor automatisms, where the behavioral manifestations have no recognized association with learning, we wondered whether the pathophysiological mechanisms of chronic focal epilepsy had subserved in this case a psychological learning process, whereby right temporal seizures were ultimately able to recruit and activate an adjacent neural memory circuit.
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PMID:The sign of the cross as a learned ictal automatism? 1939 65

High frequency oscillations (HFOs) have been associated with epileptogenicity. In rats, the extent of HFOs (>200 Hz) is correlated with seizure frequency. We studied whether the same applies to patients with focal epilepsy. Thirty-nine patients with intracerebral EEG sampled at 2000 Hz were studied for interictal ripples (80-250 Hz), fast ripples (FR, 250-500 Hz) and spikes. Seizure frequency before implantation was compared to numbers of channels with HFOs (>1/min). Analyses were repeated for HFO rates of >5, >10 and >20. Separate analyses were done for 25 patients with temporal lobe epilepsy only and for a selection of similar unilateral temporal channels in 12 patients. No linear correlation or trend was found relating the number of channels with HFOs and seizure frequency. There was a linear positive correlation between the number of channels with more than 20 FRs/min and seizure frequency. The hypothesis that the more tissue generating HFOs, the higher the seizure frequency, was not confirmed, though there might be a correlation for high FR rates.
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PMID:High frequency oscillations and seizure frequency in patients with focal epilepsy. 1940 69

Transfer entropy ( TE) is a recently proposed measure of the information flow between coupled linear or nonlinear systems. In this study, we suggest improvements in the selection of parameters for the estimation of TE that significantly enhance its accuracy and robustness in identifying the direction and the level of information flow between observed data series generated by coupled complex systems. We show the application of the improved TE method to long (in the order of days; approximately a total of 600 h across all patients), continuous, intracranial electroencephalograms (EEG) recorded in two different medical centers from four patients with focal temporal lobe epilepsy (TLE) for localization of their foci. All patients underwent ablative surgery of their clinically assessed foci. Based on a surrogate statistical analysis of the TE results, it is shown that the identified potential focal sites through the suggested analysis were in agreement with the clinically assessed sites of the epileptogenic focus in all patients analyzed. It is noteworthy that the analysis was conducted on the available whole-duration multielectrode EEG, that is, without any subjective prior selection of EEG segments or electrodes for analysis. The above, in conjunction with the use of surrogate data, make the results of this analysis robust. These findings suggest a critical role TE may play in epilepsy research in general, and as a tool for robust localization of the epileptogenic focus/foci in patients with focal epilepsy in particular.
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PMID:Information flow and application to epileptogenic focus localization from intracranial EEG. 1949 31


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