OBJECTIVE: Focal cortical dysplasia (FCD) is the most common malformation causing refractory focal epilepsy. Surgical removal of the entire dysplastic cortex is crucial for achieving a seizure-free outcome. Precise presurgical distinctions between FCD types by neuroimaging are difficult, mainly in patients with normal magnetic resonance imaging findings. However, the FCD type is important for planning the extent of surgical approach and counselling. METHODS: This study included patients with focal drug-resistant epilepsy and definite histopathological FCD type I or II diagnoses who underwent intracranial electroencephalography (iEEG). We detected interictal epileptiform discharges (IEDs) and their recruitment into repetitive discharges (RDs) to compare electrophysiological patterns characterizing FCD types. RESULTS: Patients with FCD type II had a significantly higher IED rate (p < 0.005), a shorter inter-discharge interval within RD episodes (p < 0.003), sleep influence on decreased RD periodicity (p < 0.036), and longer RD episode duration (p < 0.003) than patients with type I. A Bayesian classifier stratified FCD types with 82% accuracy. CONCLUSION: Temporal characteristics of IEDs and RDs reflect the histological findings of FCD subtypes and can differentiate FCD types I and II. SIGNIFICANCE: Presurgical prediction of FCD type can help to plan a more tailored surgical approach in patients with normal magnetic resonance findings.

• Klíčová slova
• Epilepsy, Focal cortical dysplasia, Interictal epileptiform discharges, Intracranial EEG, Repetitive discharges, Weibull mixture model,
• MeSH
• Bayesova věta MeSH
• elektroencefalografie škodlivé účinky   MeSH
• elektrokortikografie škodlivé účinky   MeSH
• epilepsie * chirurgie   MeSH
• fokální kortikální dysplazie * MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• malformace mozkové kůry * diagnostické zobrazování   chirurgie   komplikace   MeSH
• refrakterní epilepsie * diagnostické zobrazování   chirurgie   etiologie   MeSH
• retrospektivní studie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Focal cortical dysplasias (FCDs) are a range of malformations of cortical development each with specific histopathological features. Conventional radiological assessment of standard structural MRI is useful for the localization of lesions but is unable to accurately predict the histopathological features. Quantitative MRI offers the possibility to probe tissue biophysical properties in vivo and may bridge the gap between radiological assessment and ex-vivo histology. This review will cover histological, genetic and radiological features of FCD following the ILAE classification and will explain how quantitative voxel- and surface-based techniques can characterise these features. We will provide an overview of the quantitative MRI measures available, their link with biophysical properties and finally the potential application of quantitative MRI to the problem of FCD subtyping. Future research linking quantitative MRI to FCD histological properties should improve clinical protocols, allow better characterisation of lesions in vivo and tailored surgical planning to the individual.

• Klíčová slova
• Biophysical tissue properties, Epilepsy surgery, Focal cortical dysplasia, Histology, MRI, Malformation of cortical development, Quantitative MRI, Quantitative mapping, Radiology, qMRI,
• MeSH
• fenotyp * MeSH
• lidé MeSH
• magnetická rezonanční tomografie metody   statistika a číselné údaje   MeSH
• malformace mozkové kůry diagnostické zobrazování   genetika   patologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

High-frequency oscillations (HFOs) represent an electrographic biomarker of endogenous epileptogenicity and seizure-generating tissue that proved clinically useful in presurgical planning and delineating the resection area. In the neocortex, the clinical observations on HFOs are not sufficiently supported by experimental studies stemming from a lack of realistic neocortical epilepsy models that could provide an explanation of the pathophysiological substrates of neocortical HFOs. In this study, we explored pathological epileptiform network phenomena, particularly HFOs, in a highly realistic murine model of neocortical epilepsy due to focal cortical dysplasia (FCD) type II. FCD was induced in mice by the expression of the human pathogenic mTOR gene mutation during embryonic stages of brain development. Electrographic recordings from multiple cortical regions in freely moving animals with FCD and epilepsy demonstrated that the FCD lesion generates HFOs from all frequency ranges, i.e., gamma, ripples, and fast ripples up to 800 Hz. Gamma-ripples were recorded almost exclusively in FCD animals, while fast ripples occurred in controls as well, although at a lower rate. Gamma-ripple activity is particularly valuable for localizing the FCD lesion, surpassing the utility of fast ripples that were also observed in control animals, although at significantly lower rates. Propagating HFOs occurred outside the FCD, and the contralateral cortex also generated HFOs independently of the FCD, pointing to a wider FCD network dysfunction. Optogenetic activation of neurons carrying mTOR mutation and expressing Channelrhodopsin-2 evoked fast ripple oscillations that displayed spectral and morphological profiles analogous to spontaneous oscillations. This study brings experimental evidence that FCD type II generates pathological HFOs across all frequency bands and provides information about the spatiotemporal properties of each HFO subtype in FCD. The study shows that mutated neurons represent a functionally interconnected and active component of the FCD network, as they can induce interictal epileptiform phenomena and HFOs.

• Klíčová slova
• Epilepsy, Fast ripples, Focal cortical dysplasia, Gamma oscillations, High-frequency oscillations, Ripples, mTOR,
• MeSH
• elektroencefalografie MeSH
• epilepsie * MeSH
• fokální kortikální dysplazie * MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• TOR serin-threoninkinasy MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• TOR serin-threoninkinasy MeSH

Our inability to adequately treat many patients with refractory epilepsy caused by focal cortical dysplasia (FCD), surgical inaccessibility and failures are significant clinical drawbacks. The targeting of physiologic features of epileptogenesis in FCD and colocalizing functionality has enhanced completeness of surgical resection, the main determinant of outcome. Electroencephalography (EEG)-functional magnetic resonance imaging (fMRI) and magnetoencephalography are helpful in guiding electrode implantation and surgical treatment, and high-frequency oscillations help defining the extent of the epileptogenic dysplasia. Ultra high-field MRI has a role in understanding the laminar organization of the cortex, and fluorodeoxyglucose-positron emission tomography (FDG-PET) is highly sensitive for detecting FCD in MRI-negative cases. Multimodal imaging is clinically valuable, either by improving the rate of postoperative seizure freedom or by reducing postoperative deficits. However, there is no level 1 evidence that it improves outcomes. Proof for a specific effect of antiepileptic drugs (AEDs) in FCD is lacking. Pathogenic mutations recently described in mammalian target of rapamycin (mTOR) genes in FCD have yielded important insights into novel treatment options with mTOR inhibitors, which might represent an example of personalized treatment of epilepsy based on the known mechanisms of disease. The ketogenic diet (KD) has been demonstrated to be particularly effective in children with epilepsy caused by structural abnormalities, especially FCD. It attenuates epigenetic chromatin modifications, a master regulator for gene expression and functional adaptation of the cell, thereby modifying disease progression. This could imply lasting benefit of dietary manipulation. Neurostimulation techniques have produced variable clinical outcomes in FCD. In widespread dysplasias, vagus nerve stimulation (VNS) has achieved responder rates >50%; however, the efficacy of noninvasive cranial nerve stimulation modalities such as transcutaneous VNS (tVNS) and noninvasive (nVNS) requires further study. Although review of current strategies underscores the serious shortcomings of treatment-resistant cases, initial evidence from novel approaches suggests that future success is possible.

• Klíčová slova
• Drug resistance, EEG, Epilepsy surgery, Epileptogenesis, Focal cortical dysplasia, MRI, PET,
• MeSH
• antikonvulziva terapeutické užití   MeSH
• elektroencefalografie metody   MeSH
• lidé MeSH
• magnetická rezonanční tomografie metody   MeSH
• malformace mozkové kůry diagnóza   epidemiologie   terapie   MeSH
• refrakterní epilepsie diagnóza   epidemiologie   terapie   MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• antikonvulziva MeSH

PURPOSE: Focal cortical dysplasia (FCD) represents a common cause of refractory epilepsy. It is considered a sporadic disorder, but its occasional familial occurrence suggests the involvement of genetic mechanisms. METHODS: Siblings with intractable epilepsy were referred for epilepsy surgery evaluation. Both patients were examined using video-EEG monitoring, MRI examination and PET imaging. They underwent left anteromedial temporal lobe resection. RESULTS: Electroclinical features pointed to left temporal lobe epilepsy and MRI examination revealed typical signs of left-sided hippocampal sclerosis and increased white matter signal intensity in the left temporal pole. PET examination confirmed interictal hypometabolism in the left temporal lobe. Histopathological examination of resected tissue demonstrated the presence FCD type IIIa, i.e. hippocampal sclerosis and focal cortical dysplasia in the left temporal pole. CONCLUSION: We present a unique case of refractory mesial temporal lobe epilepsy in siblings, characterized by an identical clinical profile and histopathology of FCD type IIIa, who were successfully treated by epilepsy surgery. The presence of such a high concordance between the clinical and morphological data, together with the occurrence of epilepsy and febrile seizures in three generations of the family pedigree points towards a possible genetic nature of the observed FCD type IIIa.

• Klíčová slova
• Epilepsy surgery, Familial temporal lobe epilepsy, Focal cortical dysplasia, Genetics of epilepsy,
• MeSH
• dospělí MeSH
• epilepsie temporálního laloku etiologie   genetika   patologie   patofyziologie   MeSH
• lidé MeSH
• malformace mozkové kůry komplikace   genetika   patologie   patofyziologie   MeSH
• mozek diagnostické zobrazování   patologie   patofyziologie   chirurgie   MeSH
• napětím řízený sodíkový kanál, typ 1 genetika   MeSH
• radioisotopová scintigrafie MeSH
• sourozenci MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH
• Názvy látek
• napětím řízený sodíkový kanál, typ 1 MeSH
• SCN1A protein, human MeSH Prohlížeč

OBJECTIVE: Patients with tuberous sclerosis complex (TSC) present with drug-resistant epilepsy in about 60% of cases, and evaluation for epilepsy surgery may be warranted. Correct delineation of the epileptogenic zone (EZ) among multiple dysplastic lesions on MRI represents a challenging step in pre-surgical evaluation. METHODS: Two experienced neuroradiologists evaluated pre- and post-surgical MRIs of 28 epilepsy surgery patients with TSC, assessing characteristics of tubers, cysts, calcifications, and focal cortical dysplasia (FCD)-resembling lesions. Utilizing multiple metrics, we compared MRI features of the EZ-defined as the resected area in TSC patients who achieved seizure-freedom 2 years after epilepsy surgery-with features of other brain areas. Using combinatorial analysis, we identified combinations of dysplastic features that are most frequently observed in the epileptogenic zone in TSC patients. RESULTS: All TSC-associated dysplastic features were more frequently observed in the EZ than in other brain areas (increased cortical thickness, gray-white matter blurring, transmantle sign, calcifications, and tubers; Kendal's tau 0.35, 0.25, 0.27, 0.26, and 0.23, respectively; P value <.001 in all). No single feature could reliably and independently indicate the EZ in all patients. Conversely, the EZ was indicated by the presence of the combination of three of the following features: tubers, transmantle sign, increased cortical thickness, calcifications, and the largest FCD-affected area. Out of these, the largest FCD-affected area emerged as the most reliable indicator of the EZ, combined either with calcifications or tubers. SIGNIFICANCE: The epileptogenic zone in TSC patients harbors multiple dysplastic features, consistent with focal cortical dysplasia. A specific combination of these features can indicate the EZ and aid in pre-surgical MRI evaluation in epilepsy surgery candidates with TSC.

• Klíčová slova
• epilepsy surgery, focal cortical dysplasia, magnetic resonance imaging, pre-surgical evaluation, tuberous sclerosis complex,
• MeSH
• dítě MeSH
• epilepsie * komplikace   etiologie   MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• malformace mozkové kůry * komplikace   diagnostické zobrazování   patologie   MeSH
• mozek patologie   MeSH
• tuberózní skleróza * komplikace   diagnostické zobrazování   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Variants of GATOR1-genes represent a recognised cause of focal cortical dysplasia (FCD), the most common structural aetiology in paediatric drug-resistant focal epilepsy. Reports on familial cases of GATOR1-associated FCD are limited, especially with respect to epilepsy surgery outcomes. METHODS: We present phenotypical manifestations of four unrelated patients with drug-resistant focal epilepsy, FCD and a first-degree relative with epilepsy. All patients underwent targeted gene panel sequencing as a part of the presurgical work up. Literature search was performed to compare our findings to previously published cases. RESULTS: The children (probands) had a more severe phenotype than their parents, including drug-resistant epilepsy and developmental delay, and they failed to achieve seizure freedom post-surgically. All patients had histopathologically confirmed FCD (types IIa, IIb, Ia). In Patient 1 and her affected father, we detected a known pathogenic NPRL2 variant. In patients 2 and 3 and their affected parents, we found novel likely pathogenic germline DEPDC5 variants. In family 4, we detected a novel variant in NPRL3. We identified 15 additional cases who underwent epilepsy surgery for GATOR1-associated FCD, with a positive family history of epilepsy in the literature; in 8/13 tested, the variant was inherited from an asymptomatic parent. CONCLUSION: The presented cases displayed a severity gradient in phenotype with children more severely affected than the parents. Although patients with GATOR1-associated FCD are considered good surgical candidates, post-surgical seizure outcome was poor in our familial cases, suggesting that accurate identification of the epileptogenic zone may be more challenging in this subgroup of patients.

• Klíčová slova
• Epilepsy surgery, Focal cortical dysplasia, Focal epilepsy, GATOR1, Malformations of cortical development, Targeted gene panel sequencing,
• MeSH
• dítě MeSH
• fenotyp MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• malformace mozkové kůry genetika   chirurgie   MeSH
• mladiství MeSH
• nádorové supresorové proteiny genetika   MeSH
• proteiny aktivující GTPasu genetika   MeSH
• refrakterní epilepsie genetika   MeSH
• retrospektivní studie MeSH
• zárodečné mutace MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• DEPDC5 protein, human MeSH Prohlížeč
• nádorové supresorové proteiny MeSH
• NPRL2 protein, human MeSH Prohlížeč
• NPRL3 protein, human MeSH Prohlížeč
• proteiny aktivující GTPasu MeSH

AIMS: To assess the localizing value of ictal SPECT in very young epilepsy surgery candidates when cerebral haemodynamic responses are known to be immature. METHODS: We retrospectively studied 13 infants with intractable focal epilepsy caused by focal cortical dysplasia (FCD). Completeness of resection of the (1) ictal SPECT hyperperfusion zone and (2) cerebral cortex with prominent ictal and interictal abnormalities on intracranial EEG (ECoG or long-term invasive monitoring) and the MRI lesion, when present, were correlated with postoperative seizure outcome. RESULTS: All five patients with complete resection of the ictal SPECT hyperperfusion zone were seizure-free compared to only one of eight patients with incomplete or no excision of hyperperfusion zones (p=0.00843). Similar results were noted for the MRI/iEEG-defined epileptogenic region; five of six patients with complete removal were seizure-free, whereas only one of seven incompletely resected patients was seizure-free (p=0.02914). All four patients who underwent complete resection of both regions were seizure-free compared to none of the six with incomplete resection (p=0.01179). CONCLUSION: Despite age-related differences in cerebral perfusion, ictal SPECT provides useful localization data in infants with FCD. Complete resection of the hyperperfused regions is a strong predictor of favourable outcome. The added information may alleviate the need for invasive EEG evaluations in some patients.

• Klíčová slova
• epilepsy surgery, focal cortical dysplasia, ictal SPECT, infant,
• MeSH
• epilepsie parciální diagnostické zobrazování   chirurgie   MeSH
• jednofotonová emisní výpočetní tomografie normy   MeSH
• kojenec MeSH
• lidé MeSH
• malformace mozkové kůry komplikace   MeSH
• refrakterní epilepsie diagnostické zobrazování   chirurgie   MeSH
• retrospektivní studie MeSH
• výsledek terapie MeSH
• Check Tag
• kojenec MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Interictal high-frequency oscillations (HFO) were recently identified in recordings from depth macroelectrodes in epileptic patients. StereoEEG (SEEG) recordings were analyzed in four patients with medically intractable partial seizures due to focal cortical dysplasia type IIA. Characteristics of HFO within seizure onset zone (SOZ), irritative zone, and remote brain areas were investigated. Whilst the rate of occurrence for ripples (80-200 Hz) was significantly higher in recordings from within than outside the SOZ, the rate of fast ripples (200-450 Hz) was less reliable index of SOZ. Interestingly, the mean powers across subjects were significantly higher within than outside the SOZ in both ripple and fast ripple frequency ranges. Our study demonstrates a capacity of interictal HFO to detect the SOZ in focal cortical dysplasias.

• MeSH
• analýza rozptylu MeSH
• dospělí MeSH
• elektrody MeSH
• elektroencefalografie metody   MeSH
• lidé středního věku MeSH
• lidé MeSH
• magnetická rezonanční tomografie metody   MeSH
• malformace mozkové kůry komplikace   patologie   MeSH
• mapování mozku * MeSH
• mladiství MeSH
• mozek patofyziologie   MeSH
• počítačové zpracování signálu MeSH
• spektrální analýza MeSH
• záchvaty etiologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

OBJECTIVE: Epilepsy surgery fails in > 30% of patients with focal cortical dysplasia (FCD). The seizure persistence after surgery can be attributed to the inability to precisely localize the tissue with an endogenous potential to generate seizures. In this study, we aimed to identify the critical components of the epileptic network that were actively involved in seizure genesis. METHODS: The directed transfer function was applied to intracranial EEG recordings and the effective connectivity was determined with a high temporal and frequency resolution. Pre-ictal network properties were compared with ictal epochs to identify regions actively generating ictal activity and discriminate them from the areas of propagation. RESULTS: Analysis of 276 seizures from 30 patients revealed the existence of a seizure-related network reconfiguration in the gamma-band (25-170 Hz; p < 0.005) - ictogenic nodes. Unlike seizure onset zone, resecting the majority of ictogenic nodes correlated with favorable outcomes (p < 0.012). CONCLUSION: The prerequisite to successful epilepsy surgery is the accurate identification of brain areas from which seizures arise. We show that in FCD-related epilepsy, gamma-band network markers can reliably identify and distinguish ictogenic areas in macroelectrode recordings, improve intracranial EEG interpretation and better delineate the epileptogenic zone. SIGNIFICANCE: Ictogenic nodes localize the critical parts of the epileptogenic tissue and increase the diagnostic yield of intracranial evaluation.

• Klíčová slova
• Effective connectivity, Epilepsy, Intracranial EEG, Networks, Outcome, Seizure onset zone,
• MeSH
• dítě MeSH
• dospělí MeSH
• gama rytmus EEG fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• malformace mozkové kůry diagnostické zobrazování   patofyziologie   chirurgie   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mozková kůra diagnostické zobrazování   patofyziologie   chirurgie   MeSH
• následné studie MeSH
• nervová síť diagnostické zobrazování   patofyziologie   chirurgie   MeSH
• refrakterní epilepsie diagnostické zobrazování   patofyziologie   chirurgie   MeSH
• retrospektivní studie MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH