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At present, the risk factors for world-centered (allocentric) navigation impairment in patients with temporal lobe epilepsy (TLE) are not known. There is some evidence on the importance of the right hippocampus but other clinical features have not been investigated yet. In this study, we used an experimental human equivalent to the Morris water maze to examine spatial navigation performance in patients with drug-refractory unilateral TLE. We included 47 left-hemisphere speech dominant patients (25 right sided; 22 left sided). The aim of our study was to identify clinical and demographic characteristics of TLE patients who performed poorly in allocentric spatial memory tests. Our results demonstrate that poor spatial navigation is significantly associated with younger age at epilepsy onset, longer disease duration, and lower intelligence level. Allocentric navigation in TLE patients was impaired irrespective of epilepsy lateralization. Good and poor navigators did not differ in their age, gender, or preoperative/postoperative status. This study provides evidence on risk factors that increase the likelihood of allocentric navigation impairment in TLE patients. The results indicate that not only temporal lobe dysfunction itself but also low general cognitive abilities may contribute to the navigation impairment., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Hyperfamiliarity is a type of paramnesia characterized by an increased feeling of familiarity to unfamiliar faces. This dysfunction has been associated with frontal and temporal lobe pathology. The study investigated hyperfamiliarity in patients with temporal lobe epilepsy (TLE) by assessing their ability to recognize both familiar and unfamiliar faces. We evaluated 61 patients with pharmacoresistant TLE (33 right-sided, 28 left-sided) and 16 controls. The ability to recognize familiar faces was similar in patients and controls, although patients with left-sided TLE showed poorer performance in familiar face naming compared to both right-sided TLE patients and controls. Hyperfamiliarity was observed in a significantly higher number of patients with TLE compared to controls; in subgroup analysis, only right-sided TLE patients expressed hyperfamiliarity. Overall, patients with right-sided TLE showed more severe impairment compared to patients with left-sided TLE. It is proposed that hyperfamiliarity can be a relatively common symptom in patients with treatment-refractory TLE and right-sided focus., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Focal cortical dysplasias (FCDs) of the brain are recognized as a frequent cause of intractable epilepsy. To contribute to the current understanding of the mechanisms of epileptogenesis in FCD, our study provides evidence that not only cellular alterations and synaptic transmission, but also changed diffusion properties of the extracellular space (ECS), induced by modified extracellular matrix (ECM) composition and astrogliosis, might be involved in the generation or spread of seizures in FCD. The composition of the ECM in FCD and non-malformed cortex (in 163 samples from 62 patients) was analyzed immunohistochemically and correlated with the corresponding ECS diffusion parameter values determined with the real-time iontophoretic method in freshly resected cortex (i.e. the ECS volume fraction and the geometrical factor tortuosity, describing the hindrances to diffusion in the ECS). The ECS in FCD was shown to differ from that in non-malformed cortex, mainly by the increased accumulation of certain ECM molecules (tenascin R, tenascin C, and versican) or by their reduced expression (brevican), and by the presence of an increased number of astrocytic processes. The consequent increase of ECS diffusion barriers observed in both FCD type I and II (and, at the same time, the enlargement of the ECS volume in FCD type II) may alter the diffusion of neuroactive substances through the ECS, which mediates one of the important modes of intercellular communication in the brain - extrasynaptic volume transmission. Thus, the changed ECM composition and altered ECS diffusion properties might represent additional factors contributing to epileptogenicity in FCD., (© 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.)

Purpose: To gain new insights into the clinical presentation, causes, treatment and prognosis of epilepsia partialis continua (EPC), and to develop hypotheses to be tested in a prospective investigation., Methods: In this retrospective multicenter study, all cases were included that fulfilled these criteria: constantly repeated fragments of epileptic seizures, with preserved consciousness, lasting ≥ 1 h and representing locally restricted motor or sensory epileptic activity. Single episodes were included when they lasted for a minimum of 1 day. EPC with Rasmussen syndrome and acute stroke were excluded., Key Findings: Three time courses with two subtypes each were distinguished, that is, EPC as a solitary event (de novo or in preexistent epilepsy); chronic repetitive nonprogressive EPC (with frequent or rare episodes); and chronic persistent nonprogressive EPC (primarily or evolving out of an episodic course). These were unrelated to etiologies (morphologic lesions 34%, inflammatory 29%, systemic disorders 9%, idiopathic 5%, unknown 23%). Precipitation and inhibition of seizures is a frequent feature of EPC. Levetiracetam and topiramate have improved the possibilities for pharmacotherapy. Topiramate seems to be particularly effective with dysontogenetic etiologies., Significance: The existence of several clearly distinct courses of nonprogressive EPC is a new finding. These distinctions will be further investigated in a prospective study with precise protocols for electroencephalography (EEG), imaging, and other studies. This should better establish the relation of motor and somatosensory EPC; further clarify the relations, pathogenesis, and significance of the different types and their etiologies; and possibly identify more semiologic variants. It should also provide more precise knowledge about therapy and modification of ictogenesis by external stimuli., (Wiley Periodicals, Inc. © 2011 International League Against Epilepsy.)

Wormian bones are small ossicles appearing within the cranial sutures in more than 40% of skulls, most commonly at the lambdoid suture and pterion. During the skeletal analysis of an unidentified male war victim, we observed multiple wormian bones and a patent metopic suture. Additionally, the right elbow was deformed, probably as a consequence of an old trauma. The skull was analyzed by cranial measurements and computerized tomography, revealing the presence of cranial deformities including hyperbrachicrania, localized reduction in hemispheral widths, increased cranial capacity, and sclerosis of the viscerocranium. Besides unique anatomical features and their anthropological value, such skeletal abnormalities also have a forensic value as the evidence to support the final identification of the victim., (© 2011 American Academy of Forensic Sciences.)

Purpose: Minimally invasive percutaneous single trajectory stereotactic radiofrequency amygdalohippocampectomy was used to treat mesial temporal lobe epilepsy (MTLE). The aim of the study was to evaluate complications and effectiveness of this procedure., Materials and Methods: A group of 51 patients with MTLE was treated using stereotactic thermo-lesion of amygdalohippocampal complex under local anaesthesia. The target was reached through the occipital approach with a single trajectory using MRI stereotactic localisation. Thermocoagulation of the amygdalohippocampal complex was planned according to the individual anatomy of each patient. Amygdalohippocampectomy was performed using a string electrode with a 10-mm active tip, and 16-38 lesions (median = 25) were performed in all patients along the 30- to 45-mm trajectory (median = 35) in the amygdalohippocampal complex., Results: The procedure was well tolerated by all patients with no severe permanent morbidity; meningitis was recorded in two patients (4%), hematoma was detected in four patients, clinically insignificant in three of them, and one patient required temporary ventricular drainage (2%). Thirty-two patients were followed up over at least 2 years, and the clinical outcomes were evaluated by Engel's classification; 25 of them (78%) were Engel I, five (16%) were Engel II, and two (6%) were Engel IV., Conclusions: Stereotactic amygdalohippocampectomy is a minimally invasive procedure with low morbidity and good results that can be the method of choice in selected patients with MTLE.

Focal cortical dysplasias (FCDs) represent a prominent cause of pharmacologically intractable epilepsy. In FCD, the decrease of parvalbumin immunoreactive (PV+) inhibitory interneurons has been repeatedly documented. Here, we wanted to show whether another interneuronal population, the calretinin immunoreactive (CR+) neurons, exhibits any change in human FCD. We also investigated samples of morphologically normal temporal neocortex resected together with sclerotic hippocampus (nHSTN), where decrease of PV+ interneurons was previously documented as well. Brain tissue from 24 patients surgically treated for pharmacoresistant epilepsy was examined. Calretinin immunoreactivity was qualitatively evaluated and the density of CR+ neuronal profiles was quantified. As a control, post-mortem acquired neocortical samples of nine patients without any brain affecting disease were used. CR+ neurons were located predominantly in superficial cortical layers both in controls and pathological samples. Similarly, the morphology of CR+ neurons was unaffected in pathological samples. The overall density of CR+ neurons was significantly decreased in FCD type I (to approximately 70% of control values) and even more in FCD type II (to approximately 50% of controls). In nHSTN, no change compared to controls was found in CR+ neuronal density. Our results may contribute to the better understanding of the role of individual interneuronal populations in epileptogenesis., (2009 Elsevier B.V. All rights reserved.)

We performed a retrospective, multicenter, open-label study to evaluate the efficacy of vagus nerve stimulation (VNS) in all patients in the Czech Republic who have received this treatment for at least 5 years (n=90). The mean last follow-up was 6.6+/-1.1 years (79+/-13 months). The median number of seizures among all patients decreased from 41.2 seizures/month in the prestimulation period to 14.9 seizures/month at 5 years follow-up visit. The mean percentage of seizure reduction was 55.9%. The responder rate in these patients is in concordance with the decrease of overall seizure frequency. At 1 year after beginning the stimulation, 44.4% of patients were responders; this percentage increased to 58.7% after 2 years. At the 5 years last follow-up 64.4% of patients were responders, 15.5% experienced > or = 90% seizure reduction, and 5.5% were seizure-free. A separate analysis of patients younger than 16 years of age showed lower efficacy rates of VNS in comparison to the whole group. Complications and chronic adverse effects occurred in 13.3% of patients. VNS is an effective and safe method to refractory epilepsy in common clinical practice.

Background: Mesial temporal lobe epilepsy (MTLE) with hippocampal sclerosis (HS) constitutes a distinct clinical syndrome with variable pathogenesis. Extrahippocampal regions may be affected in MTLE/HS, association with cortical dysplasia is common and temporal polar cortex is frequently involved in seizure onset. Patients with dual pathology may have favourable outcome from the surgery provided that both pathologies are removed. The aim of the study was to review clinical variables of MTLE/HS patients in order to distinguish preoperatively patients with associated microscopic cortical dysplasia in the temporal pole., Methods: A series of 38 patients with the clinical diagnosis of MTLE and histopathologically proven HS were analysed. Patients were divided into two groups on the basis of histopathological finding in the temporal polar cortex: HS associated with malformation of cortical development (group HS+, n = 19) and a group with isolated HS (group HS, n = 19). Demographic, clinical, electrographic and seizure semiology variables were obtained and their prevalence compared between both groups., Results: At least one insult was identified in early childhood history of 18 patients in the HS group in comparison to 10 patients in the HS+ group (p < 0.01). Complicated febrile seizures were found in both groups with similar prevalence, the history of early childhood CNS infection prevailed in the HS group (p < 0.01). Absence of aura was reported in HS group only. Patients in the the HS+ group had earlier surgery (p < 0.05) but the seizure outcome was comparable between groups., Conclusions: Microscopic dual pathology is common in MTLE/HS patients. This group of patients is difficult to distinguish preoperatively on the basis of noninvasive electrographic features or ictal clinical semiology. Detailed information regarding the possible precipitating insult in the history may be of critical importance.

Proton magnetic resonance spectroscopy ((1)H MRS) is beneficial in the lateralization of the epileptogenic zone in temporal lobe epilepsy; however, its role in extratemporal and, especially, MRI-negative epilepsy has not been established. This study seeks to verify how (1)H MRS could help in localizing the epileptogenic zone in patients with MRI-negative extratemporal epilepsy. Seven patients (8-23 years) with MRI-negative refractory focal epilepsy were studied using (1)H MRS on a 1.5T MR system. Chemical shift imaging sequence in the transversal plane was directed towards the suspected epileptogenic zone localized by seizure semiology, scalp video/EEG, ictal SPECT and (18)FDG-PET. Spectra were evaluated using the program CULICH, and the coefficient of asymmetry was used for quantitative lateralization. MRS detected lateralization in all patients and was able to localize pathology in five. The most frequent findings were decreased ratios of N-acetylaspartate to choline compounds characterized by increasing choline concentration. The localization of the (1)H MRS abnormality correlated well with ictal SPECT and subdural mapping. In all cases, histopathological analysis revealed MRI-undetected focal cortical dysplasias. (1)H MRS could be more sensitive for the detection of discrete malformations of cortical development than conventional MRI. It is valuable in the presurgical evaluation of patients without MRI-apparent lesions.

Digital signal processing techniques are often used for measurement of small time shifts between EEG signals. In our work we tested properties of linear cross-correlation and phase/coherence method. The last mentioned method was used in two versions. The first version used fast Fourier transform (FFT) algorithm and the second was based on autoregressive modeling with fixed or adaptive model order. Methods were compared on several testing signals mimicking real EEG signals. The accuracy index for each method was computed. Results showed that for long signal segments all methods bring comparably good results. Accuracy of FFT phase/coherence method significantly decreased when very short segments were used and also decreased with an increasing level of the additive noise. The best results were obtained with autoregressive version of phase/coherence. This method is more reliable and may be used with high accuracy even in very short signals segments and it is also resistant to additive noise.

Purpose: Focal cortical dysplasia (CD) is increasingly recognized as a common pathologic substrate of medically intractable epilepsy. As these lesions are often localized in the frontal lobe (therefore in potentially eloquent cortex), an understanding of the functional status of the involved region(s) and of its anatomic and pathologic correlates is of prime importance. The purpose of this study is to assess the function of focal CD in relation to magnetic resonance imaging (MRI) and histopathologic features., Methods: Eight patients operated on for medically intractable epilepsy with histologically proven focal CD involving putative eloquent cortex in the frontal lobe (perirolandic and Broca's areas) were included in the study. Functional regions (motor and language) and epileptogenic areas were assessed by extraoperative electrocorticographic recording and electrical cortical mapping. Cortical functions were correlated with the extent of epileptogenicity on electrocorticographic recordings, MRI features, and histologic characteristics., Results: Language or motor areas were colocalized with epileptogenic regions (n=6 of 8, 75%), but were not mapped in regions of increased signal on fluid-attenuated inversion recovery (FLAIR) MRI (when they were identified) on preoperative MRI (n=5 of 5, 100%). Histologically, balloon cells were almost exclusively found in nonfunctional regions with FLAIR MRI abnormalities. When resected, regions of motor cortex were characterized by cortical dyslamination, columnar disorganization, and dysmorphic neurons, but were devoid of balloon cells., Conclusions: We found an absence of language or motor functions in perirolandic and Broca's areas that showed decreased epileptogenicity, histopathological evidence of CD with balloon cells and FLAIR MRI signal increase. Language and motor functions were present in epileptogenic and dysplastic areas with no balloon cells and no FLAIR signal abnormalities. These findings have implications on options for epilepsy surgery in patients with CD.

The nocturnal eating syndrome (NES) is a nocturnal sleep disorder caused by repeated awakening and the inability to fall a sleep again unless the patient ingests some food or drinks something. In children the NES is frequent, in adults rather rare and may be associated with various pathological conditions. The latter include in particular somnabulism, periodic movements of the lower extremities, narcolepsy, chronic triazolam intoxication, probably anorexia nervosa, and other eating disorders. The authors submit two case-histories of middle aged women (30 and 37 years old) without disturbances of the day-time eating behaviour, without obvious psychopathology where the symptomatology of NES developed slowly from the age of 14 and 25 years resp. Both patients ate at night small amounts of easily consumed foods which they went to fetch in the kitchen as often as five times per night. Their behaviour was calm and aimed. Usually they did not remember the nocturnal eating. Polysomnographic examination in both patients revealed poor sleep with frequent changes of the sleep stages, with frequent awakenings, in both patients incl. even awakening from deep NREM sleep. The authors conclude that in these two patients NES with somnabulism is involved.