Lesional Epilepsy Research Articles

A meta-analysis of case-reports and case-series of dacrystic epilepsy in children and adolescence

This meta-analysis aimed to advance our knowledge about dacrystic epilepsy in children in the present time. PubMed searches for peer-reviewed case reports and case series were conducted using the keywords “dacrystic epilepsy”, “dacrystic seizures”, “crying epilepsy”, “ictal crying”, “crying seizures”. The databases were developed in accordance with preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. The author collected relevant information to characterise the study population including clinical outcome. Eleven studies out of 353 citations between 1998 and 26 May 2021 met the inclusion criteria, including both single cases and series pertaining to dacrystic epilepsy. Eight case reports and three case series were eligible for this meta-analysis and included twenty one cases. The seizure patterns were dacrystic seizures alone in seven cases (33%), and a combination of dacrystic seizures and gelastic seizures in fourteen cases (67%). Neuroimaging revealed structural abnormality in 95% cases. Hypothalamic hamartoma was found in most of the cases (79%) with combined dacrystic seizures and gelastic seizures, whereas it was found in one case (16%) with dacrystic seizures alone. The other underlying lesions in children with dacrystic seizures alone were subependymal nodules and cortical hamartomas (17%), left mesial temporal sclerosis (33%), and cortical dysplasia (17%). Regarding outcome, antiepileptic drugs alone achieved seizure freedom in four cases (22%) only and others (78%) were difficult to treat cases excluding three cases where treatments were not mentioned. Six cases underwent surgical intervention and two cases received ablative radiotherapy. Lesional dacrystic epilepsy is predominant and pharmaco-resistant in children. However, antiepileptic drugs lead to achieving seizure remission in few cases.

A multimodal neuroimaging approach to non lesional frontal lobe epilepsy

Frontal Lobe Epilepsy (FLE) is a common form of epilepsy usually caused by structural lesions on frontal areas. Some FLE patients are defined “non-lesional” (nlFLE) because of the absence of clearly identifiable abnormalities on qualitative brain MRI. Our aim was to investigate nlFLE patients to identify possible microstructural abnormalities, through advanced neuroimaging techniques.

Does the Modified Arrhenius Model Reliably Predict Area of Tissue Ablation After Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for Pediatric Lesional Epilepsy?

Commercial magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) systems utilize a generalized Arrhenius model to estimate the area of tissue damage based on the power and time of ablation. However, the reliability of these estimates in Vivo remains unclear. To determine the accuracy and precision of the thermal damage estimate (TDE) calculated by commercially available MRgLITT systems using the generalized Arrhenius model. A single-center retrospective review of pediatric patients undergoing MRgLITT for lesional epilepsy was performed. The area of each lesion was measured on both TDE and intraoperative postablation, postcontrast T1 magnetic resonance images using ImageJ. Lesions requiring multiple ablations were excluded. The strength of the correlation between TDE and postlesioning measurements was assessed via linear regression. A total of 32 lesions were identified in 19 patients. After exclusion, 13 pairs were available for analysis. Linear regression demonstrated a strong correlation between estimated and actual ablation areas (R2=.97, P<.00001). The TDE underestimated the area of ablation by an average of 3.92% overall (standard error (SE)=4.57%), but this varied depending on the type of pathologic tissue involved. TDE accuracy and precision were highest in tubers (n=3), with average underestimation of 2.33% (SE=0.33%). TDE underestimated the lesioning of the single hypothalamic hamartoma in our series by 52%. In periventricular nodular heterotopias, TDE overestimated ablation areas by an average of 13% (n=2). TDE reliability is variably consistent across tissue types, particularly in smaller or periventricular lesions. Further investigation is needed to understand the accuracy of this emerging minimally invasive technique.

Outcome of epilepsy surgery in lesional epilepsy: Experiences from a developing country

BackgroundOur aim was to report the postoperative seizure outcome and associated factors in patients with lesional epilepsy, in a low-income setting. MethodsThis longitudinal prospective study included patients who underwent epilepsy surgery at Kashani Comprehensive Epilepsy Center between 2014 and 2019. Post-surgical outcomes were reported according to the Engel score, and patients were classified into two groups of seizure free (SF) and not-seizure free (NSF). ResultsA total of 148 adult patients, with a mean age of 30.45 ± 9.23 years were included. The SF outcome was reported in 86.5% of patients and antiepileptic drugs (AEDs) were reduced or discontinued in 45.9%. The mean follow-up duration was 26.7 ± 14.9 months. Temporal lobe lesions (76.3%) and mesial temporal sclerosis (MTS) (56.7%) were the most frequent etiologies. Temporal lesion (Incidence relative risk (IRR): 1.76, 95% CI [1.08–2.87], p = 0.023), prior history of CNS infection (IRR:1.18, 95% CI [1.03–1.35], p = 0.019), use of intra-operative ECoG (IRR:1.73, 95% CI [1.06–2.81], p = 0.028), and absence of IEDs in postoperative EEG (IRR: 1.41, 95% CI [1.18–1.70], p < 0.001) were positive predictors for a favorable outcome. ConclusionMany patients with drug-resistant lesional epilepsy showed a favorable response to surgery. We believe that resective epilepsy surgery in low-income settings is a major treatment option. The high frequency of patients with drug-resistant epilepsy in developing countries is associated with high rates of morbidity and mortality. Hence, strategies to increase access to epilepsy surgery in these settings are urgently needed.

Adopting MR-guided stereotactic laser ablations for epileptic lesions: initial clinical experience and lessons learned.

MR-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive technique for ablating brain lesions under real-time MRI feedback and control of the ablation process. The Medtronic Visualase system was recently approved for use in Europe and Israel. We report our initial technical experience using the system in the first 16 cases in which the system was used to ablate focal epileptogenic lesions. We included all consecutive patients with intractable epilepsy who underwent MRgLITT procedures between 2018 and 2020. We reviewed medical charts and imaging studies of patients. Post-ablation MRIs were used to calculate ablation volumes. Seventeen MRgLITT procedures were performed in 16 patients. One cooling catheter/laser fiber assemblies were placed per patient. Indications for surgery were intractable epilepsy due to TLE (n = 7),suspected low-grade glioma (n = 4), radiological cortical dysplasia (n = 1), hypothalamic hamartoma (n = 1), and MR-negative foci (n = 3). Ablations were made using 30 to 70% of the maximal energy of the Visualase system. We used serial ablations as needed along the tract of the catheter by pulling back the optic fiber; the length of the lesion ranged between 7.4 and 38.1mm. Ablation volume ranged between 0.27 and 6.78 mm3. Immediate post-ablation MRI demonstrated good ablation of the epileptic lesion in 16/17 cases. In one case with mesial temporal sclerosis, no ablation was performed due to suboptimal position of the catheter. That patient was successfully reoperated at a later date. Mean follow-up was 14.9months (± 11.6months). Eleven patients had follow-up longer than 12months. Good seizure control (Engel I, A) was achieved in 7/11 patients (63%) and 1/11 (9%) had significant improvement in seizure frequency (Angle IIIa). Three patients (27%) did not experience improvement in their seizure frequency (Engel IV, B), and one of these patients died during the follow-up period from sudden unexpected death of epilepsy (SUDEP). No immediate or delayed neurological complications were documented in any of the cases during the follow-up period. MRgLITT is a promising technique and can be used safely as an alternative to open resection in both lesional and non-lesional intractable epilepsy cases. In our local series, the success rate of epilepsy surgery was comparable to recent publications.

P 20. Stimulus-dependent behavioural disorder in patients with ANT-DBS for Epilepsy

Deep brain stimulation (DBS) targeting the anterior nucleus of the thalamus (ANT) is as an effective and safe treatment option for patients with resistant epilepsy. A SANTE Study reported that there was a gradual improvement in selected neuropsychological test results in patient with DBS in ANT. Among those improvements there were reported a number of psychiatric adverse affects. However little is studied about immediate neuropsychological effects of DBS in ANT. Recently demonstrated Voges B. et. al (2015) a stimulus- and voltage-dependent effect interrupting sleep and leading to the occurrence of neuropsychiatric symptoms (npS) (e.g. depression, mood instability, disturbed sleep) during ATN-DBS. We here present one patient with a voltage-independent developing of npS during ANT-DBS. The 45-year-old right-handed female patient with mental retardation with autistic spectrum disorder presented with focal not lesional refractory epilepsy. The average seizure frequency was 6.1 per day with a range of 1 to 16 seizures daily. After failure of 13 AED“s, a DBS-ANT was initiated at the age of 44. Follow up simultaneous EEG- video recording from 26 surface electrode contacts after beginning to stimulate with standard parameters (unipolar cyclic (1min ON/5min OFF) stimulation with 5 V stimulation amplitude, 120 Hz stimulation frequency and a pulse width of 90 μs) there were seen a directly dependence of neuropsychiatric symptoms (stereotypical movements with sitting down, torso wiggling (Body rocking) with or without singing) and impulse onset. In video-EEG monitoring we determined, that the duration of npS was also the same as impulse lasts. A clinical response to stimulation was 84 %. We improve adverse effects changing the programming settings: the amplitude was gradually reduced to two volts, the stimulation frequency 120 Hz and a pulse width of 90 μs where the same. Actual case report devoted to immediate complex behavioural disorder, which does not fulfil criteria for a complex focal seizure, and is strongly associated with unipolar bilateral stimulation of ANT. The actual clinical presentation of the DBS induced behavioural disorder semiologically coincide with the term “stereotypic movement disorder”. We hypothesize that impaired function of ARAS lead to reduced behavioural suppression of impulse mediated behaviour in the patient with mental retardation. We analysed her video-EEG before she was being stimulated and noticed, that she already had a typical body movement (body rocking) but much less frequently. Obviously a DBS of ANT had had a strong influence on behavioural disorder of our patient and was reversible after adjusting the stimulation parameters.

TEMPORAL LOBE EPILEPSY (PAST, PRESENT, AND THE FUTURE)

Background: The temporal lobe is the most epileptogenic region of the human brain. There are two types of temporal lobe epilepsy (TLE), the medial involves the medial or internal structures, and neocortical involves the outer portion of the temporal lobe. It can be associated with a magnetic resonance imaging (MRI) lesion or be non-lesional. The main causes of lesional TLE are Herpes simplex, benign tumors, vascular malformations, cortical development malformations, and post-traumatic or post-infectious gliosis. Objective: To discuss temporal lobe epilepsy with all its different causes, evaluating different modalities of treatment, obstacles in applying all modalities in developing countries, and ways to overcome these obstacles with future scope of epilepsy treatment especially temporal lobe epilepsy. Patients and methods: The study performed on twenty patients admitted to Al-Hussein and Sayed Galal University hospitals, and Al-Ahrar teaching hospital. There were pre-surgical evaluations by a multidisciplinary team of neurologists, clinical neurophysiologists, neuroradiologist, epileptologists, psychologists, psychiatrists, and neurosurgeons. Most of cases were temporal lobe lesional epilepsy. Surgical management was carried out for the included patients according to present pathology. Results: Our patients' ages ranged from 7 to 55 years old with the mean age of 21.2 ± 13.79 years. 60% were in 2nd decade. 70% of patients were males and 30% were females, 90% were right handed and 10% left handed. The range of duration of the disease was 2-8 years with the mean 4.1 ± 2.125 years. As regard MRI pathological findings; 10% normal, 10% left temporal sclerosis, 10% right insular dysplasia, 5% right temporal encephalomalacia, 10% temporal covernoma, 10% temporal arachnoid cyst, 5% right temporal epidermoid cyst and 40% temporal neoplastic lesions of MRI findings. 55% Left temporal epileptic discharge, 25% right temporal epileptic discharge, 10% bilateral temporal epileptogenic activity with tendency to generalization and 10% normal of EEG. 65% lesional excision, 10% excision and fenestration of cyst to subarachnoid space, 15% amygdalohippocampectomy, and 15% temporal lobectomy. Among the patients surgically operated, 4 patients (20%) had temporarily complications. Conclusion: Temporal lobe epilepsy surgeries provided a good chance for seizure control when the clinical and radiological data were concordant with seizure semiology, in particular with tumor-related epilepsy. TLE surgery can be safe when performed by experienced surgeons.

Magnetic source imaging in presurgical evaluation of paediatric focal drug-resistant epilepsy and its predictive value of surgical outcome in lesional cases: A single-centre experience from South India

ObjectiveThis study aims to evaluate the utility of magnetoencephalography in presurgical planning and in predicting post-surgical seizure outcome. MethodsThis study included a cohort of 231 children (1–18 years) with focal drug-resistant epilepsy who underwent MEG as a part of their presurgical workup. Characteristics of MEG observations were described in all children. The concordance and agreement of Magnetic Source Imaging (MSI) of interictal discharges (IED) was estimated with either of the 3 subgroups - MRI lesion; presumed epileptogenic zone (EZ); or resection cavity. In operated children group, MEG dipole characteristics between good and poor outcome groups were assessed. ResultsA total of 153 cases (66.2%) showed frequent IEDs (60 spikes/60 min). Of the 173 cases where MSI showed clusters (74.9%), 151 had lesions and 22 were non-lesional. amongst patients with lesional epilepsy and MEG clusters, class I concordance (MEG localization either completely included or overlapped at least 60% with the MRI lesion) was seen in 60.92% with a Cohen's kappa of 0.608. In non-lesional epilepsy, class I concordance of MEG with presumed EZ was found in (81.81%) with an agreement of 0.317. Fifty-three children underwent surgery of whom 39 (73.58%) showed a good outcome (Engel I). In operated children, concordance between MEG focus and resection cavity was observed in 23 (58.97%) with good outcome and in 12 (86.72%) with poor outcome with no significant difference (p>0.05). However, MEG cluster regular organization and clusterectomy are associated with good seizure outcome postoperatively (p< 0.05). Presence of scatters were associated with poor outcome (p<0.05) in children with focal cortical dysplasia. ConclusionsMEG provides useful information that can serve as a biomarker for prognosticating the surgical outcome in paediatric epilepsy. Cluster removal and regular cluster organization shows predictive power in post-surgical prognostication in children and the presence of scatters predicts poor outcome in children with focal cortical dysplasia.

All that glitters: Contribution of stereo-EEG in patients with lesional epilepsy

ObjectiveTo determine the contribution of stereo-EEG for localization purpose in patients with a visible lesion on MRI. BackgroundIntracranial EEG is often used to localize the epileptogenic focus in patients with non-lesional focal epilepsy. Its role in cases where a lesion is visible on MRI can be even more complex and the relationship between the lesion and the seizure onset has rarely been addressed. MethodsAll consecutive patients between February 2013 and May 2018 who underwent stereo-EEG and had a lesion visible on MRI were included. We assessed the localization of the seizure onset and its relationship with the lesion. Clinical, radiological, and electrographic analyses were performed. ResultsStereo-EEG revealed a seizure onset with either partial or no overlap with the lesion seen on MRI in 42 (56 %) of the 75 lesions included. Mesial temporal sclerosis was the only lesion type associated with an exclusively lesional seizure onset (p = 0.003). ConclusionEpilepsy surgery in MRI-positive cases should rely not only the results of lesions seen on MRI, which might be potentially misleading; SEEG is a gold standard method in these cases to define resective borders.

Robotic-Guided Stereoelectroencephalography for Refractory Epilepsy: Technique and Nuances.

Stereoelectroencephalography (SEEG) has become an integral part of epilepsy surgery, often used in the localization of the epileptogenic zone. It is an essential modality not only in the evaluation of nonlesional but also lesional drug refractory epilepsy, especially in the presence of anatomo-electro-clinical discordance. To describe our technique and the operative nuances involved in the performance of robotic SEEG placement. A 28-year lady with seizure onset at the age of 15 years presented with two types of seizures: one was associated with an aura of chest discomfort, palpitations along with oral and bilateral automatisms. There was associated speech and behavioral arrest along with ictal urinary incontinence. The other type has head turning to the right with secondary generalization lasting up to 1 min. Multimodality investigations showed bilateral temporal origin of seizures. SEEG evaluation revealed left amygdala and anterior temporal neocortical (ATL) origin of seizures. The patient underwent left ATL and amygdalectomy. Histopathology revealed focal cortical dysplasia (FCD type Ib). The patient became seizure free (ILAE Class 1) at 1-year follow up. Robotic-guided SEEG is a safe and accurate method of evaluating complex MRI negative epilepsy.

Assessment of the response to antiepileptic drugs in epileptic patients with structural lesion(s) on neuroimaging

BackgroundFocal epilepsy is the most common form of epilepsy in adults. Advances in brain imaging allowed better identification of different structural lesions underlying focal epilepsy. However, the response to antiepileptic drugs in lesional epilepsy is heterogeneous and difficult to anticipate. This study aimed to evaluate the response to antiepileptic drugs (AED) in patients with lesional epilepsy and to identify the predictors for poor seizure control.MethodsOne hundred and sixty-five patients with lesional epilepsy were included; the clinical diagnosis of epilepsy and seizure classification was based on the revised criteria of the International League Against Epilepsy (ILAE). Patients were subjected to full clinical assessment, MRI brain imaging epilepsy protocol, and EEG monitoring. All subjects were followed in the epilepsy clinic for at least 6 months.Results75.8% of patients with lesional epilepsy showed poor response to antiepileptic medications. Cerebromalatic lesions related to brain trauma was the most frequently encountered (21.8%). Malformations of cortical development were significantly associated with poor response to AED (p = 0.040). Polytherapy and the combined use of 1st- and 2nd-generation AED were higher in the poor response group. Logistic regression analysis revealed that younger age at seizure onset and abnormal EEG findings was 0.965 times and 2.5 times more associated with poor seizure control, respectively.ConclusionThis study revealed that patients with lesional epilepsy who develop seizures in their early life, who suffer from malformations of cortical development, or who show abnormal EEG findings are more suspected to show poor response to AED.

Perampanel as add-on therapy in epilepsies with known etiology: A single center experience with long-term follow-up.

We report a retrospective monocentric study performed on 63 patients affected by epilepsy with known etiology, receiving perampanel as add-on therapy with at least 12-month follow-up. The purpose of our study was to evaluate efficacy and tolerability of perampanel in this group of epilepsies. Patients were classified into 2 groups based on the presence/absence of a single focal brain lesion on MRI, as epilepsy etiology: 48 subjects were affected by focal lesional epilepsy and 15 by non-focal lesional epilepsy. The retention rate was 76.2% and 53.9% at 12 and 24months respectively. At 12months, at least 40% of patients resulted responders, with a significant reduction in seizure frequency (p=0.01), confirmed at 24months. Considering epilepsy etiology, we found a better PER response in patients with focal lesional epilepsy. A significant correlation was observed between responderrates and EEG pattern. Only 30% of patients reported mild-moderate adverse events. Efficacy and tolerability of PER, in our study, are in line with the results reported in other real-world studies. Our data suggest the possibility of better PER response in patients with focal brain lesions, which indicates that this drug could be a therapeutic option in this population.

Patterns and predictors of language representation and the influence of epilepsy surgery on language reorganization in children and young adults with focal lesional epilepsy.

Mapping brain functions is crucial for neurosurgical planning in patients with drug-resistant seizures. However, presurgical language mapping using either functional or structural networks can be challenging, especially in children. In fact, most of the evidence on this topic derives from cross-sectional or retrospective studies in adults submitted to anterior temporal lobectomy. In this prospective study, we used fMRI and DTI to explore patterns of language representation, their predictors and impact on cognitive performances in 29 children and young adults (mean age at surgery: 14.6 ± 4.5 years) with focal lesional epilepsy. In 20 of them, we also assessed the influence of epilepsy surgery on language lateralization. All patients were consecutively enrolled at a single epilepsy surgery center between 2009 and 2015 and assessed with preoperative structural and functional 3T brain MRI during three language tasks: Word Generation (WG), Rhyme Generation (RG) and a comprehension task. We also acquired DTI data on arcuate fasciculus in 24 patients. We first assessed patterns of language representation (relationship of activations with the epileptogenic lesion and Laterality Index (LI)) and then hypothesized a causal model to test whether selected clinical variables would influence the patterns of language representation and the ensuing impact of the latter on cognitive performances. Twenty out of 29 patients also underwent postoperative language fMRI. We analyzed possible changes of fMRI and DTI LIs and their clinical predictors. Preoperatively, we found atypical language lateralization in four patients during WG task, in one patient during RG task and in seven patients during the comprehension task. Diffuse interictal EEG abnormalities predicted a more atypical language representation on fMRI (p = 0.012), which in turn correlated with lower attention (p = 0.036) and IQ/GDQ scores (p = 0.014). Postoperative language reorganization implied shifting towards atypical language representation. Abnormal postoperative EEG (p = 0.003) and surgical failures (p = 0.015) were associated with more atypical language lateralization, in turn correlating with worsened fluency. Neither preoperative asymmetry nor postoperative DTI LI changes in the arcuate fasciculus were observed. Focal lesional epilepsy associated with diffuse EEG abnormalities may favor atypical language lateralization and worse cognitive performances, which are potentially reversible after successful surgery.

Stereotactic MRI-guided laser interstitial thermal therapy for extratemporal lobe epilepsy.

Magnetic resonance imaging (MRI)-guided laser interstitial thermal therapy (MRg-LITT) is an alternative to open epilepsy surgery. We assess safety and effectiveness of MRg-LITT for extratemporal lobe epilepsy (ETLE) in patients who are considered less favorable for open resection. We retrospectively reviewed sequential cases of patients with focal ETLE who underwent MRg-LITT between 2012 and 2019. Epileptogenic zones were determined from standard clinical and imaging data±stereoelectroencephalography (SEEG). Standard stereotactic techniques, MRI thermometry, and a commercial laser thermal therapy system were used for ablations. Anatomic MRI was used to calculate ablation volumes. Clinical outcomes were determined longitudinally. Thirty-five patients with mean epilepsy duration of 21.3±12.2years underwent MRg-LITT for focal ETLE at a mean age 36.4±12.7years. A mean 2.59±1.45 trajectories per patient were used to obtain ablation volumes of 8.8±7.5cm3 . Mean follow-up was 27.3±19.5months. Of 32 patients with >12months of follow-up, 17 (53%) achieved good outcomes (Engel class I+II) of whom 14 (44%) were Engel class I. Subgroup analysis revealed better outcomes for patients with lesional ETLE than for those who were nonlesional, multifocal, or who had failed prior interventions (P=.02). Of 13 patients showing favorable seizure-onset patterns (localized low voltage fast activity or rhythmic spiking on SEEG) prior to ablation, 9 (69%) achieved good outcomes, whereas only 3 of 11 (27%) who show other slower onset patterns achieved good outcomes. Minor adverse events included six patients with transient sensorimotor neurologic deficits and four patients with asymptomatic hemorrhages along the fiber tract. Major adverse events included one patient with a brain abscess that required stereotactic drainage and one patient with persistent hypothalamic obesity. Three deaths-two seizure-associated and one suicide-were unrelated to surgical procedures. MRI-guided laser interstitial thermal therapy (or MRg-LITT) was well-tolerated and yielded good outcomes in a heterogeneous group of ETLE patients. Lesional epilepsy and favorable seizure-onset patterns on SEEG predicted higher likelihoods of success.

Epilepsy subtype-specific copy number burden observed in a genome-wide study of 17 458 subjects.

Cytogenic testing is routinely applied in most neurological centres for severe paediatric epilepsies. However, which characteristics of copy number variants (CNVs) confer most epilepsy risk and which epilepsy subtypes carry the most CNV burden, have not been explored on a genome-wide scale. Here, we present the largest CNV investigation in epilepsy to date with 10 712 European epilepsy cases and 6746 ancestry-matched controls. Patients with genetic generalized epilepsy, lesional focal epilepsy, non-acquired focal epilepsy, and developmental and epileptic encephalopathy were included. All samples were processed with the same technology and analysis pipeline. All investigated epilepsy types, including lesional focal epilepsy patients, showed an increase in CNV burden in at least one tested category compared to controls. However, we observed striking differences in CNV burden across epilepsy types and investigated CNV categories. Genetic generalized epilepsy patients have the highest CNV burden in all categories tested, followed by developmental and epileptic encephalopathy patients. Both epilepsy types also show association for deletions covering genes intolerant for truncating variants. Genome-wide CNV breakpoint association showed not only significant loci for genetic generalized and developmental and epileptic encephalopathy patients but also for lesional focal epilepsy patients. With a 34-fold risk for developing genetic generalized epilepsy, we show for the first time that the established epilepsy-associated 15q13.3 deletion represents the strongest risk CNV for genetic generalized epilepsy across the whole genome. Using the human interactome, we examined the largest connected component of the genes overlapped by CNVs in the four epilepsy types. We observed that genetic generalized epilepsy and non-acquired focal epilepsy formed disease modules. In summary, we show that in all common epilepsy types, 1.5-3% of patients carry epilepsy-associated CNVs. The characteristics of risk CNVs vary tremendously across and within epilepsy types. Thus, we advocate genome-wide genomic testing to identify all disease-associated types of CNVs.

Relationship between PET metabolism and SEEG epileptogenicity in focal lesional epilepsy.

This study aims to evaluate the performance of 18F-FDG PET for distinguishing the epileptogenic zone (EZ) from propagation and non-involved zones at brain area level, as defined using stereo-EEG (SEEG), in patients with pharmacoresistant epilepsy due to malformations of cortical development (MCD). Additionally, we seek to determine the relationship between 18F-FDG-PET data and post-surgical seizure outcome. Thirty-eight patients with MCD were explored with 18F-FDG PET and SEEG. We compared PET metabolism of each patient to a control population of healthy subjects. Based on MRI and SEEG, we separated 4 distinct zones at individual level: lesional, epileptogenic non-lesional, propagation, and non-involved. Then, we analysed (1) difference of PET metabolism within these four distinct zones; (2) performance of PET in defining the EZ within the SEEG-sampled areas; and (3) relation between extension of PET hypometabolism and post-surgical seizure outcome. We found (1) a gradient of PET hypometabolism from non-involved to propagation, then to epileptogenic and lesional zones (p < 0.001); (2) good performance of PET in defining the EZ (AUC of ROC curve = 0.82); (3) poorer post-surgical prognosis associated with PET hypometabolism extension beyond SEEG sampling (p = 0.024). 18F-FDG-PET has good accuracy in determining EZ in patients with MCD even if the hypometabolism is not limited to the EZ. Furthermore, hypometabolic extension is unfavourably associated with post-surgical prognosis.

Congruence and Discrepancy of Interictal and Ictal EEG With MRI Lesions in Pediatric Epilepsies.

Purpose. To evaluate the congruence or discrepancy of the localization of magnetic resonance imaging (MRI) lesions with interictal epileptiform discharges (IEDs) or epileptic seizure patterns (ESPs) in surface EEG in lesional pediatric epilepsy patients. Methods. We retrospectively analyzed presurgical MRI and video-EEG monitoring findings of patients up to age 18 years. Localization of MRI lesions were compared with ictal and interictal noninvasive EEG findings of patients with frontal, temporal, parietal, or occipital lesions. Results. A total of 71 patients were included. Localization of ESPs showed better congruence with MRI in patients with frontal lesions (n = 21, 77.5%) than in patients with temporal lesions (n = 24; 40.7%) (P = .009). No significant IED distribution differences between MRI localizations could be found. Conclusions. MRI lesions and EEG findings are rarely fully congruent. Congruence of MRI lesions and ESPs was highest in children with frontal lesions. This is in contrast to adults, in whom temporal lesions showed the highest congruency with the EEG localization of ESP. Lesional pediatric patients should be acknowledged as surgical candidates despite incongruent findings of interictal and ictal surface EEG.

Seizures following surgery for supratentorial extratemporal low-grade tumors in children: a multicenter retrospective study.

Resection of brain tumors may lead to new-onset seizures but may also reduce seizure rates in patients presenting with seizures. Seizures are seen at presentation in about 24% of patients with brain tumors. For lesional epilepsy in general, early resection is associated with improved seizure control. However, the literature is limited regarding the occurrence of new-onset postoperative seizures, or rates of seizure control in those presenting with seizures, following resections of extratemporal low-grade gliomas (LGGs) in children. Data were collected retrospectively from 4 large tertiary centers for children (< 18 years of age) who underwent resection of a supratentorial extratemporal (STET) LGG. The patients were divided into 4 groups based on preoperative seizure history: no seizures, up to 2 seizures, more than 2 seizures, and uncontrolled or refractory epilepsy. The authors analyzed the postoperative occurrence of seizures and the need for antiepileptic drugs (AEDs) over time for the various subgroups. The study included 98 children. Thirty patients had no preoperative seizures, 18 had up to 2, 16 had more than 2, and 34 had refractory or uncontrolled epilepsy. The risk for future seizures was higher if the patient had seizures within 1 month of surgery. The risk for new-onset seizures among patients with no seizures prior to surgery was low. The rate of seizures decreased over time for children with uncontrolled or refractory seizures. The need for AEDs was higher in the more active preoperative seizure groups; however, it decreased with time. The resection of STET LGGs in children is associated with a low rate of postoperative new-onset epilepsy. For children with preoperative seizures, even with uncontrolled epilepsy, most have a significant improvement in the seizure activity, and many may be weaned off their AEDs.

Treatments for the prevention of Sudden Unexpected Death in Epilepsy (SUDEP).

Treatments for the prevention of Sudden Unexpected Death in Epilepsy (SUDEP).

Safety of the paramedian supracerebellar-transtentorial approach for selective amygdalohippocampectomy.

The goal of this study was to assess the reproducibility and safety of the recently introduced paramedian supracerebellar-transtentorial (PST) approach for selective amygdalohippocampectomy (SA). The authors performed a retrospective analysis of prospectively collected data originating from their surgical register of patients undergoing SA via a PST approach for lesional medial temporal lobe epilepsy. All patients received thorough pre- and postoperative clinical (neurological, neuropsychological, psychiatric) and instrumental (ictal and long-term EEG, invasive EEG if needed, MRI) workup. Surgery-induced complications were assessed at discharge and at every follow-up thereafter and were classified according to Clavien-Dindo grade (CDG). Epilepsy outcome was defined according to Engel classification. Data were reported according to common descriptive statistical methods. Between May 2015 and May 2018, 17 patients underwent SA via a PST approach at the authors' institution (hippocampal sclerosis in 13 cases, WHO grade II glioma in 2 cases, and reactive gliosis in 2 cases). The median postoperative follow-up was 7 months (mean 9 months, range 3-19 months). There was no surgery-related mortality and no complication (CDG ≥ 2) in the whole series. Transitory CDG 1 surgical complications occurred in 4 patients and had resolved in all of them by the first postoperative follow-up. One patient showed a deterioration of neuropsychological performance with new slight mnestic deficits. No patient experienced a clinically relevant postoperative visual field defect. No morbidity due to semisitting position was recorded. At last follow-up 13/17 (76.4%) patients were in Engel class I (9/17 [52.9%] were in class IA). The PST approach is a reproducible and safe surgical route for SA. The achievable complication rate is in line with the best results in the literature. Visual function outcome particularly benefits from this highly selective, neocortex-sparing approach. A larger patient sample and longer follow-up will show in the future if the seizure control rate and neuropsychological outcome also compare better than those achieved with current common surgical techniques.