Search

Highlights • Significance of auras on surgical outcome in drug-resistant temporal lobe epilepsy was studied. • Presence or absence of auras had no bearing on surgical outcome after anterior temporal lobectomy. • Auditory and vertiginous auras are red herrings while selecting candidates for ATL. • Ictal onset zone should be delineated in patients with auditory and vertiginous auras before ATL. Abstract Purpose The success of epilepsy surgery lies in identifying the ictal onset zone accurately. The significance of auras has little been explored on surgical outcome in drug-resistant epilepsy. This study focuses on the clinicopathological correlation of aura(s) and its role in predicting surgical outcome in drug-resistant temporal lobe epilepsy (TLE). We compared surgical outcome in TLE between patients with and without aura and identified the clinico-pathological, radiological and surgical differences between the two groups. Methods Consecutive patients who underwent presurgical evaluation from January 2009 to December 2014 for drug-resistant TLE who underwent anterior temporal lobectomy (ATL) were included. Patients were followed up at 3months, 12 months and then annually. Results Among 456 patients, 344(75%) had aura. Multivariate logistic regression showed that prototype EEG pattern at ictal onset (OR 2.12, 95% CI 1.18–3.06, p = 0.012) and right sided epileptogenic zone (OR 1.82 95% CI 1.18–3.78, p = 0.007) were significantly associated with presence of aura. There was no difference in surgical outcome between those with and without aura. But patients with auditory aura (OR 7.28, CI 2.80–18.95, p = 0.0002) and vertiginous aura (OR 3.01, CI 1.55–7.85, p = 0.028) had a poor surgical outcome. Bivariate analysis showed that normal MRI (p = 0.028) and normal/indeterminate pathology (p = 0.001) were significantly more common with auditory/vertiginous auras. Conclusions Mere presence of aura does not affect outcome after TLE surgery. However, auditory and vertiginous auras are predictors of poor surgical outcome. These patients require more extensive screening for an ictal onset zone beyond standard limits of ATL before surgery. [ABSTRACT FROM AUTHOR]

Drug-resistant focal epilepsy is a common occurrence in patients with gray matter nodular heterotopia (NH), and surgical treatment is often considered in these cases. NH-related epileptogenicity is sustained by complex networks, which may involve the nodules and extralesional cortex in various combinations. Therefore, invasive EEG is usually required to identify the structures involved in seizure generation. It has been reported that surgery may be effective in cases with unilateral lesions, whereas bilateral cases are not optimal candidates for surgical success. Furthermore, violation of cortical and subcortical structures for approaching deep-seated nodules may result in neurological deficits. For these reasons, selective stereotactic ablation with radiofrequency thermocoagulation (RFTC) has been proposed as an alternative option in these patients. In particular, RFTC may be performed by using the same recording intracerebral electrodes implanted for stereo-electro-encephalo-graphy (SEEG) monitoring, with the advantage of a reliable electro-clinical guide. Excellent results on seizures have been initially reported following coagulation of single, unilateral NH. Subsequent experience has indicated that, basing on the evidence of SEEG recording, promising results may be obtained also in more extended unilateral and bilateral cases. In more complex cases, coagulation of both the nodules and of the involved extralesional cortical structures is often required. In a recently reported series, 67% of patients experienced sustained seizure freedom after the procedure. However, post RFTC seizure outcome in complex cases (NH plus other malformations of cortical development) is not as good as in other patterns of NH. RFTC, especially if guided by SEEG evaluation, should be considered as a first-line treatment option in NH-related epilepsy. Satisfactory results may be obtained also in cases not amenable to traditional surgery. The procedure is safe and does not prevent eventual resective surgery in case of failure in seizure control. For these reasons, in patients undergoing SEEG evaluation, electrode arrangement should be planned with the aim to cover as extensively as possible the heterotopic and extralesional areas, which will presumably be the targets of RFTC. [ABSTRACT FROM AUTHOR]

Several surgical options are available for treating hypothalamic hamartoma-related epilepsy but their respective efficacy and safety profiles are poorly defined. A literature search identified English-language articles reporting series of patients (minimum 3 patients with a follow-up ≥12 months) operated on by either microsurgery, endoscopic surgery, radiosurgery, radiofrequency thermocoagulation or laser interstitial thermal therapy for hypothalamic hamartoma-related epilepsy. The unit of analysis was each selected study. Pooled rates of seizure freedom and of neurological and endocrinological complications were analyzed using meta-analysis to calculate both fixed and random effects. The results of meta-analyses were compared. Thirty-nine studies were included. There were 568 and 514 participants for seizure outcome and complication analyses, respectively. The pairwise comparison showed that: i) the proportion of seizure-free cases was significantly lower for radiosurgery as compared to microsurgery, radiofrequency thermocoagulation and laser ablation, and significantly lower for endoscopic surgery as compared to radiofrequency thermocoagulation; ii) the proportion of permanent hypothalamic dysfunction was significantly higher for microsurgery as compared to all other techniques, and significantly lower for endoscopic surgery as compared to radiofrequency thermocoagulation and laser ablation; iii) the incidence of permanent neurological disorders was significantly higher for microsurgery as compared to endoscopic surgery, radiosurgery and radiofrequency thermocoagulation, and significantly lower for radiosurgery as compared to laser ablation. Minimally invasive surgical techniques, including endoscopic surgery, radiofrequency thermocoagulation and laser ablation, represent an acceptable compromise between efficacy and safety in the treatment of hypothalamic hamartoma-related epilepsy. Microsurgery and radiosurgery should be considered in carefully selected cases. • Open microsurgery, despite a favorable impact on seizures, presents with the highest risks of complications. • Radiosurgery has the most favorable safety profile at the expense of the poorest seizure outcome. • Endoscopic surgery, radiofrequency thermocoagulation and laser ablation represent a compromise between safety and efficacy. • Customizing the choice of the surgical technique, based on patient features, should be the direction of future research. [ABSTRACT FROM AUTHOR]

Purpose To determine the factors predicting seizure outcome in children who underwent anterior temporal lobectomy (ATL) for drug-resistant temporal lobe epilepsy (TLE). Methods Among the 664 patients who underwent ATL for TLE from 1995 to 2008, there were 134 children. “Excellent” outcome in them was defined as seizure freedom during the entire follow-up (Engel class I a); “good outcome”, if in remission last 2 years, and the rest as “unfavorable outcome”. To identify the potential predictors of seizure recurrence, the attributes of recurred and non-recurred groups was compared by univariate and multivariate analysis. Results Of the 134 children, at a mean post-operative follow-up of 8.1 years, there were 82 (61.1%) with excellent outcome and 26 (19.4%) with good outcome (category-1; seizure-free, 80.6%). Drugs could be successfully withdrawn in 69 (63.9%). 26 patients (22.4%) had seizure recurrence, (category-2, treatment/surgical failure).Whereas, of the 530 adults who underwent ATL during this time period, only 46.8% never had seizures (category-1) and 53.2% had seizure recurrence in the form of acute post-operative seizures or auras or habitual or non-habitual seizures ( category-2).The hazard of seizure recurrence in children increased with positive family history of seizures and /or epilepsy, normal neuroimaging, spikes in post-operative EEG at 3-months, normal histopathology and duration of epilepsy ≥5 years. Conclusions The information on the predictive factors causing seizure recurrence/freedom in children with drug-resistant TLE is important in surgical selection. Surgery for pediatric TLE results in favorable outcome, hence one should subject children for resective surgery at the earliest especially in lesions known to cause refractoriness. [ABSTRACT FROM AUTHOR]

Objective Hippocampal sclerosis (HS) is the most prevalent pathology in temporal lobe epilepsy (TLE) characterized by segmental neuronal cell loss in the cornu ammonis (CA) 1–4. In addition, migration of granule cells and reorganization of their axons is observed, known as granule cell dispersion (GCD) and mossy fiber sprouting (MFS). The loss of mossy fibers` (MF) target cells in CA4 and CA3 was considered to be causative for MFS. The ILAE HS (International League Against Epilepsy) classification identifies three subtypes with different cell loss patterns in CA1-4. We studied the relation of ILAE HS subtypes to GCD and MFS to corroborate clinico-pathological subgroups in a large retrospective single-center series. Material and methods Hippocampal specimen of 319 patients were screened, 214 could be used for analysis. Immunohistochemical stainings for semi-quantitative analysis of neuronal cell loss (NeuN) and MFS (synaptoporin) were performed. Presurgical data were available from patient files and seizure outcome was classified according to Engel score after surgery. Results In 39 patients (18%) no neuronal cell loss (ILAE no-HS), no GCD and no MFS was observed. In 154 patients (72%) severe neuronal cell loss was seen in CA1, CA4 and CA3 (ILAE HS 1, typical HS); in addition extensive GCD and MFS was observed. In 17 patients (8%) cell loss was seen predominantly in CA1 (ILAE HS 2); despite different cell loss pattern these hippocampi also showed GCD and MFS. In 4 patients (2%) cell loss was predominately detected in CA3 and CA4 (ILAE HS type 3), consecutively GCD and MFS were observed. Longer epilepsy duration and younger age at surgery was more often associated with ILAE HS 2 and febrile convulsions were completely absent in ILAE no-HS. Yet, seizure onset, age at initial precipitating injury and postsurgical seizure outcome did not show any significant association with ILAE HS subtypes. Conclusion GCD and MFS might develop independently from the neuronal cell loss of MF target cells. [ABSTRACT FROM AUTHOR]

In the surgical management of epilepsy, the resection of cortex exhibiting interictal fast ripples (250–500 Hz) on electrocorticography has been linked to postoperative seizure-freedom. Although fast ripples appear to accurately identify the epileptogenic zone—the minimum tissue that must be removed at surgery to achieve seizure-freedom—it has not been established that fast ripples are a superior biomarker in comparison with multimodal presurgical neuroimaging and other electrocorticography abnormalities. Hence, in the prediction of postoperative seizure-freedom, we compared the value of fast ripples with other intraoperative electocorticography abnormalities including focal slowing, paroxysmal fast activity, intermittent spike discharges, continuous epileptiform discharges, focal attenuation, and intraoperative seizures, as well as complete resection of the lesion defined by MRI and other neuroimaging. In a cohort of 60 children with lesional epilepsy and median postsurgical follow-up exceeding 4 years, who underwent resective epilepsy surgery with intraoperative electrocorticography, we evaluated the extent to which removal of each intraoperative electrocorticography abnormality impacts time to first postoperative seizure using the Kaplan-Meier method and Cox proportional hazards regression. Secondly, we contrasted the predictive value of resection of each competing electrocorticography abnormality using standard test metrics (sensitivity, specificity, positive predictive value, and negative predictive value). In contrast with all other intraoperative electrocorticography abnormalities, fast ripples demonstrated the most favorable combination of positive predictive value (100%) and negative predictive value (76%) in the prediction of postoperative seizures. Among all candidate electrocorticography features, time to first postoperative seizure was most strongly associated with incomplete resection of fast ripples (hazard ratio = 19.8, p < 0.001). In multivariate survival analyses, postoperative seizures were independently predicted by incomplete resection of cortex generating fast ripples (hazard ratio = 25.4, 95%CI 6.71–96.0, p < 0.001) and focal slowing (hazard ratio = 5.79, 95%CI 1.76–19.0, p = 0.004), even after adjustment for the impact of an otherwise complete resection. All children with incomplete resection of interictal FR-generating cortex exhibited postoperative seizures within six months. Notably, this cohort included many patients with large resections and thus limited opportunity to exhibit unresected fast ripples. Future study in a cohort with small resection volume, or a clinical trial in which resection margins are guided by fast ripple distribution, would likely yield a more precise estimate of the risk posed by unresected fast ripples. With a high detection rate during brief intraoperative electrocorticography and favorable positive and negative predictive value, interictal fast ripple characterization during surgery is a feasible and useful adjunct to standard methods for epilepsy surgery planning, and represents a valuable spatially-localizing biomarker of the epileptogenic zone, without the need for prolonged extraoperative electrocorticography. [ABSTRACT FROM AUTHOR]

Objective To describe the surgery outcomes of RE patients in one centerto identify the indication for surgical treatment that results in the most favorable outcome. Method Forty-five RE patients from a single center were retrospectively reviewed. Preoperative evaluations included assessments of clinical manifestations, cognitive status, a physical examination, MRI, positron emission tomography (PET), electroencephalography (EEG), and magnetoencephalography (MEG). The surgical outcomes included seizure outcome, neurological function, EEG, a cognitive evaluation, and antiepileptic drug withdrawal. Results A total of 45 children (29 male) with RE were included in this study. The mean follow-up period from the first operation was 31.7months (range 6–96). The patients who underwent anatomical hemispherectomy or hemisphere disconnection had better seizure outcomes without greater perioperative complications compared with the patients who underwent functional hemispherectomy. Reoperative hemispherectomy was a safe and effective treatment for patients with postoperative epilepsy recurrence. After the last surgery, 34 patients (74.4%) were evaluated as Engel class I. Most of the patients had favorable neurological outcomes. Analysis revealed that the patientswith IQs greater 70 who underwent operations were more likely to suffer from IQ declines but were also more likely to have higher IQs in the future. Significance Compared with functional hemispherectomy and hemisphere disconnection, anatomical hemispherectomy elicited better seizure outcomes with an acceptable level of complications. Early stage operations might lead to better cognitive status, but they are associated with a high risk of IQ decline. [ABSTRACT FROM AUTHOR]

Objective The most frequent finding in temporal lobe epilepsy is hippocampal sclerosis, characterized by selective cell loss of hippocampal subregions CA1 and CA4 as well as mossy fiber sprouting (MFS) towards the supragranular region and granule cell dispersion. Although selective cell loss is well described, its impact on mossy fiber sprouting and granule cell dispersion remains unclear. Materials and methods In a single center series, we examined 319 human hippocampal specimens, collected in a 15-years period. Hippocampal specimens were stained for neuronal loss, granule cell dispersion (Wyler scale I–IV, Neu-N, HE) and mossy fiber sprouting (synaptoporin-immunohistochemistry). For seizure outcome Engel score I–IV was applied. Results In Wyler I and II specimens, mossy fibers were found along their natural projection exclusively in CA4 and CA3. In Wyler III and IV, sprouting of mossy fibers into the molecular layer and a decrease of mossy fibers in CA4 and CA3 was detected. Mean granule cell dispersion was extended from 121 μm to 185 μm and correlated with Wyler III-IV as well as mossy fiber sprouting into the molecular layer. Wyler grade, mossy fiber sprouting and granule cell dispersion correlated with longer epilepsy duration, late surgery and higher preoperative seizure frequency. Parameters analyzed above did not correlate with postoperative seizure outcome. Discussion Mossy fiber sprouting might be a compensatory phenomenon of cell death of the target neurons in CA4 and CA3 in Wyler III–IV. Axonal reorganization of granule cells is accompanied by their migration and is correlated with the severity of cell loss and epilepsy duration. [ABSTRACT FROM AUTHOR]

Objective We hypothesized that the extensive epileptic network in patients with tuberous sclerosis complex (TSC) manifests as clustered and scattered distributions of magnetoencephalography spike sources (MEGSS). Methods We retrospectively analyzed pre-surgical MEG in 15 patients with TSC. We performed single moving dipole analysis to localize and classify clustered and scattered MEGSS. We compared the number of electrodes within the resected area (RA) and the proportions of clustered and scattered MEGSS within RA with the seizure outcome. Results The number of electrodes within RA ranged from 29 to 83 (mean = 51). The MEGSS were distributed over multiple lobes (3–8; mean = 5.9) and bilaterally in 14 patients. Clusters of MEGSS ranged from 1 to 4 (mean = 1.4). The number of MEGSS ranged in total from 28 to 139 (mean = 70); in the clusters, 10–128 (mean = 49); and in the scatters, 0–45 (mean = 21). Four patients achieved an Engel class I surgical outcome, four, a class II outcome; five, a class III outcome; and two, a class IV outcome. The proportion of MEGSS ranged in total from 0 to 92% (mean = 57%) within RA; 0–100% (mean = 67%) in the resection hemisphere; 0–100% (mean = 63%) in the clusters; and 0–81% (mean = 28%) in the scatters. Univariate ordinal logistic regression analyses showed that the proportion of scattered MEGSS within RA (p = 0.049) significantly correlated with seizure outcomes. Multivariate analyses using three covariates (number of electrodes, proportions of clustered and scattered MEGSS within RA) showed that only the proportion of scattered MEGSS within RA significantly correlated with seizure outcomes (p = 0.016). Significance MEG data showed a wide distribution of multilobar MEGSS in patients with TSC. The seizure outcome was not related to the clustered MEGSS within RA, since the grids were essentially planned to cover and resect the clustered MEGSS surrounding tubers. The maximal possible resection of scattered MEGSS correlated with improved seizure outcome in TSC. Some parts of the epileptogenic zone disrupted by multiple tubers did not have a sufficiently large area to produce clustered MEGSS. Although the wide distribution of scattered MEGSS is not interpreted as epileptogenic, they might be interrelated with clustered MEGSS to project a complex epilepsy network and be part of the extensive epileptogenic zones found in TSC. [ABSTRACT FROM AUTHOR]

Objective Fast ripples (FR, 250–500 Hz) are proposed biomarkers of the epileptogenic zone on the basis of several retrospective reports linking postoperative seizure freedom to their complete resection. There are no clinical trials or prospective reports validating the use of FR as characterized by electrocorticography (ECoG), to guide the scope of epilepsy surgery, and to inform prognosis thereafter. We set out to prospectively evaluate the utility of FR resection to predict postoperative epilepsy outcomes, and examine the feasibility of “live” intraoperative FR ascertainment. Methods FR were prospectively reviewed in 30 consecutive pediatric cases including 11 reviewed “live” during surgery. Intraoperative ECoG studies were recorded at 2000 Hz sampling rate, interpreted conventionally to guide surgical resection, and visually inspected for FR. Seizure outcome was tallied for all 30 children. Results Median age at surgery was 9.1 years (interquartile range [IQR] 4.7–13.2), median ECoG duration was 10.5 min (IQR 8.0–13.2), and median postoperative follow-up was 58.4 months (IQR 25.7–79.0). FR were identified in 24 of 30 ECoG studies. The incomplete resection of FR was strongly linked to postoperative seizures (hazard ratio 11.6, p = 0.005). “Live” ECoG review in the operating room to ascertain FR proved feasible and did not differ from conventional FR ascertainment. Significance: In a prospective fashion, including “live” review, FR were detected in 80% of pediatric ECoG studies, and incomplete resection of FR cortex predicted postoperative seizures. These findings extend the notion that interictal FR are surrogate markers of the epileptogenic zone, and that their intraoperative localization could be used to inform prognosis and guide surgical resections in children. [ABSTRACT FROM AUTHOR]

Object The intention of our study was to identify predictive characteristics for long-term seizure control and running down phenomenon after surgical treatment of pharmacoresistant mesiotemporal lobe epilepsy (mTLE) with and without associated cortical dysplasia. Materials and methods Our study comprises a consecutive series of 458 patients who underwent surgical treatment for intractable mTLE at the Epilepsy Center Freiburg. Data evaluated included semiology, duration and frequency of seizures, results of presurgical diagnostics including video-EEG monitoring, MRI, PET and SPECT as well as postoperative seizure outcome. Results were evaluated forming two groups: Group A consisted of isolated mesiotemporal lesions. Group B comprised patients with mTLE and additional focal cortical dysplasia (FCD). Statistical evaluation was based on the Kaplan Meier survival analysis, using log-rank-tests and a multivariate regression model. Postoperative running down phenomenon was defined as seizure freedom after a period of gradual reduction of postoperative seizure frequency. This was compared to patients with ongoing epilepsy. Results Complete seizure freedom was achieved in 65.0% of investigated patients at 1 year and in 56.5% at long-term follow-up of ≥5 years after surgery. Corresponding results were 64.2% and 56.8% at 1 and ≥5 years, respectively in group A and 66.4% and 56.0%, respectively in group B. Predictive for favorable postoperative outcome in the total group were younger age at surgery, shorter duration of epilepsy, absence of secondarily generalized tonic-clonic seizures (SGTCS), presence of strictly ipsilateral temporal interictal epileptiform discharges (IEDs), complete resection of the lesion as well as absence of postoperative epileptiform activity and of early postoperative seizures. In subgroup analyses, patients of group A demonstrated longer postoperative seizure-free intervals with adolescent age at surgery, short duration of epilepsy before surgery and absence of SGTCS, whereas in patients of group B ipsilateral temporal seizure onset and strictly unilateral IEDs in EEG as well as complete resection were predictors for favorable seizure outcome. Furthermore, absence of early postoperative seizures and of spikes in EEG were predictive factors for long-term seizure-freedom in both subgroups. The running down phenomenon was found in 33 (7.2%) patients. None of the parameters evaluated demonstrated significant predictive power. Only late seizure onset and neoplastic lesions showed a trend for postoperative gradual seizure reduction in multivariate analyses. Conclusion Depending on the presence or absence of focal cortical dysplasia in addition to mesiotemporal structural alterations, predictors of long-term seizure control differed regarding the relevant clinical and electrophysiological features. This is important for specific patient counseling in respective groups. [ABSTRACT FROM AUTHOR]

Purpose To evaluate the long-term safety and seizure outcome in Japanese patients with Lennox–Gastaut syndrome (LGS) receiving adjunctive rufinamide therapy. Subjects and methods We conducted an open-label extension study following a 12-week multicenter, randomized, double-blind, placebo-controlled study of adjunctive rufinamide therapy in Japanese patients with LGS. Fifty-four patients participated in the extension study. Seizure frequency was evaluated until 52 weeks after the start of the extension study. Adverse events (AEs) were evaluated throughout both studies. Key findings Of the 54 patients, 41 (75.9%) completed the extension study. The median duration of exposure to rufinamide was 818.0 days in all 54 patients, and 38 patients (70.4%) received rufinamide for 2 years or more. The median percent change in the frequency of tonic–atonic seizures relative to the frequency at the start of the double-blind study was −39.3% (12 weeks), −40.6% (24 weeks), −46.8% (32 weeks), −47.6% (40 weeks), and −36.1% (52 weeks). Reduction of total seizure frequency was also maintained until 52 weeks. Frequent treatment-related AEs were somnolence (20.4%), decreased appetite (16.7%), transient seizure aggravation including status epilepticus (13.0%), vomiting (11.1%), and constipation (11.1%). Adverse events were mild or moderate, except for transient seizure aggravation in three patients. Adverse events resulting in discontinuation of rufinamide were decreased appetite, drug eruption, and worsening of underlying autism. When clinically notable weight loss was defined as a decrease ≥7% relative to baseline, 22 patients (40.7%) experienced weight loss at least once during long-term observation, although weight loss was reported as an AE in only three patients. Significance This study demonstrated a long-term benefit of rufinamide as adjunctive therapy for Japanese patients with LGS. Exacerbation of seizures and decreased appetite/weight loss should be monitored carefully. [ABSTRACT FROM AUTHOR]

Summary We analyzed peri-ictal electrocorticography below 70 Hz by a semiautomatic quantitative method. Thirty-four patients with medically intractable temporal lobe epilepsy underwent chronic electrocorticography using subdural electrodes. The resection extent of cortices with maximum amplitude activities were compared between seizure outcome groups. In detected activity significantly related to seizure outcome, we analyzed waveforms with automated waveform amplitude analysis. Mann–Whitney U tests were used. Mean follow-up duration was 49.7 ± 18.2 months. The resection extents of maximum amplitude activities in theta bands during the period between −10 and −5 s from the ictal onset were significantly different between seizure outcome groups (adjusted p = 0.01, the Benjamini–Hochberg correction). Delta, alpha and beta bands were related to seizure outcome only without multiple comparison corrections (unadjusted p = 0.02, 0.03 and 0.04). Waveform peak amplitudes greater than 200 μV tended to be more common in the seizure free group than in the non-seizure-free group (unadjusted p = 0.06). Waveform peak amplitudes greater than 350 μV were significantly more common in the cortical dysplasia type I group than in the hippocampal sclerosis group (unadjusted p = 0.03). The resection of theta band activities during the preictal period was most important for good seizure outcome in temporal lobe epilepsy. [ABSTRACT FROM AUTHOR]

Summary Intracranial electroencephalographic monitoring with subdural and/or depth electrodes is widely used for the surgical localization of epileptic foci in patients with intractable partial epilepsy; however, data on safety and surgical outcome with this technique are still inadequate. The aims of this study were to assess the morbidity of intracranial recordings and the surgical outcomes in epileptic children. We retrospectively reviewed the clinical data for 137 children with epilepsy (mean age at implantation: 12.6 ± 3.8 years) who underwent intracranial monitoring with the implantation of strip or grid subdural electrodes and/or intracerebral depth electrodes from September 2004 to September 2011 at a tertiary epilepsy center in China. Complications were classified using five grades of severity (including mortality) and were further classified as either minor or severe. Outcome was classified according to Engel's classification. Regression analysis was performed to identify risk factors for complications. The mean duration of implantation was 5.3 ± 1.3 days. Among the 133 patients who underwent resection, 65 (48.9%) were seizure free (Engel Class I) at last known follow-up, which was >2 years after surgery for all patients. Also, 31 (23.3%) patients had a significant reduction in seizures (Engel Class II). Complications of any type were documented in 29 (21.7%) patients; 15 of these patients had intracranial hematoma. The results of multivariate analysis showed that the only independent risk factor for intracranial hematoma was number of electrode contacts. The most common pathologic diagnosis was focal cortical dysplasia ( n = 58). Our results showed that intracranial electroencephalographic monitoring in children provides good surgical outcomes and the level of risk is acceptable. When using this technique strategies such as using as few electrode contacts as possible should be adopted to minimize the risk of intracranial hematoma. [ABSTRACT FROM AUTHOR]

Highlights: [•] Study population consisted of uniform group of patients with MTLE. [•] Majority (87%) had pathologically verified hippocampal sclerosis. [•] Selection for surgery was not influenced by Wada results. [•] One of the largest study to report the seizure outcome in patients with Wada failure. [•] Wada test was found to be only modestly useful for predicting seizure outcome. [ABSTRACT FROM AUTHOR]

Summary: Purpose: In some patients, resective epilepsy surgery can be planned based on a non-invasive work-up. However, in many cases, invasive monitoring with intracranial electrodes is required prior to recommending a resective procedure. Although the results of intracranial recordings are usually conclusive, a small group of patients may require additional electrodes to better define the seizure onset or propagation. Methods: One hundred and seventy seven patients who underwent intracranial electrode insertion between January 2000 and June 2005 were reviewed. Twelve of these patients required a supplementary implantation prior to making a recommendation about resective surgery. We report the nature of implantation as well as the outcomes in these 12 patients. Results: The mean age of these patients was 35 years (7 males). An average of 2.5 additional strip electrodes were required resulting in a mean of 9 strip type electrodes per patient, for a mean total of an additional 20 days. For most patients (9/12) this subsequent procedure identified an area of epileptic cortex other than that originally hypothesized. Seven patients went on to surgery of which three experienced a significant improvement in seizure control. Conclusions: The addition of supplementary electrodes to an ongoing invasive electrode investigation can be a useful means of clarifying a patient''s suitability for a resective surgical procedure. While the surgical outcomes may not be as favorable as in patients in whom the investigations are simpler, a proportion of these patients do benefit from the eventual resective procedure. In cases where the supplementary electrodes lead to the conclusion that surgery is not indicated, these patients can be satisfied that the surgical option has been explored to the fullest extent possible. [Copyright &y& Elsevier]

Summary: Purpose: Studies of adults who underwent temporal lobectomy for intractable temporal lobe epilepsy (TLE) demonstrated declining seizure free rates over time. Using seizure and social parameters, we followed patients who had temporal lobe surgery (TLS) in childhood to determine long-term outcomes. Methods: We identified 42 patients who underwent TLS for medically intractable epilepsy during childhood. Follow-up data were collected from 10 to 20 years after surgery (median, 12 years). We studied histopathology, seizure outcome, employment, school enrolment, and driver''s licensing. Patients or parents graded their satisfaction with TLS. Results: Number of Engel class I patients was 34 (81%) after 6months; 32 (76%) after 1 year; 30 (71%) after 5 years; and 28 (67%) at last ≥10 years follow-up. Nineteen (79%) of 24 children with tumors or cavernous angioma achieved class I outcomes in contrast to 9 (50%) of 18 children with other pathologies (p <0.05). Ten (56%) of 18 recurrent seizure patients experienced seizures within the first year; 4 required reoperation for seizure freedom. More seizure free patients (24, 86%) than residual seizure patients (8, 57%) were employed or in school (p =0.05). Twelve (63%) of 19 eligible patients obtained driver''s licenses. Twenty-three (82%) of 28 seizure free patients discontinued anticonvulsants. Surgery grading averaged “satisfied.” Class I patients reported greater satisfaction than class III/IV patients (p <0.001). Conclusion: Two-thirds of children who underwent TLS achieved seizure freedom at ≥10 year follow-up. Children with tumors or cavernous angiomas achieved better long-term outcomes than those with other histopathologies. Long-term seizure free patients were most often satisfied with surgery and employed or in school. [Copyright &y& Elsevier]

• TPO and frontal disconnection are effective treatments for epilepsy in children. • A brain lesion contained within the disconnection is associated with good outcomes. • Younger patients appear more likely to experience favourable post-op outcomes. In this study, we investigate the seizure outcomes of temporo-parieto-occipital (TPO) and frontal disconnections or resections in children with drug-resistant epilepsy (DRE) in order to determine factors which may predict surgical results. Children with DRE, who underwent either TPO or frontal disconnection or resection at Great Ormond Street Hospital for Children between 2000 and 2017, were identified from a prospectively collated operative database. Demographic data, age at surgery, type of surgery, scalp EEGs and operative histopathology were collected. Magnetic resonance imaging (MRI) was assessed to determine completeness of disconnection and presence of radiological lesion beyond the disconnection margins. Seizure outcome at 6, 12, and 24 months post-surgery was assessed using the Engel Scale (ES). Logistic regression was used to identify relationships between data variables and seizure outcome. 46 children (males = 28, females = 18; age range 0.5–16.6 years) who underwent TPO (n = 32, including a re-do disconnection) or frontal disconnection or resection (n = 15) were identified. Patients in the TPO treatment group had more favourable seizure outcomes than those in the frontal treatment group (ES I–II in 56 % vs 47 % at 6 months, 52 % vs 46 % at 12 months). Presence of the lesion beyond disconnection boundaries and older age at the time of surgery were associated with poorer seizure outcome. Gender, surgery type, completeness of disconnection, scalp EEG findings and underlying pathology were not related to seizure outcome, but subgroup numbers were small. Both TPO and frontal disconnection are effective treatments for selected children with posterior multi-lobar or diffuse frontal lobe epilepsy. Confinement of the MRI lesion within the disconnection margins and a younger age at surgery are associated with favourable seizure outcomes. Further studies are required to elucidate these findings. [ABSTRACT FROM AUTHOR]

• Anterior partial corpus callosotomy (ACC) was insufficient to control drop attacks. • Total corpus callosotomy (TCC) yielded more favorable seizure outcomes. • The maximum period for full ADL recovery was approximately two months after TCC. • TCC is preferred for adolescents and young adults with severe mental retardation. The aim of this study was to evaluate seizure outcomes and postoperative neurologic complications, with an emphasis on the recovery period of activities of daily living (ADL) between anterior partial corpus callosotomy (ACC) and total corpus callosotomy (TCC) in adolescent and young adults with drop attacks and severe mental retardation. We retrospectively reviewed the clinical records of consecutive patients with intractable epilepsy who underwent corpus callosotomy (CC) for drop attacks between 2010 and 2019 in the Department of Neurosurgery, Hiroshima University hospital, with a minimum follow-up of one year. Inclusion criteria of this study were 1) age at surgery: 11–39 years, 2) preoperative intelligence quotient <35, and 3) preoperative Barthel index (BI) ≥30. Postoperative full ADL recovery was defined as complete recovery to the preoperative BI score. We compared the postoperative days required for 1) recovery of oral intake ability, 2) discharge from our hospital, 3) returning home from any hospital, 4) returning home with full ADL recovery, and 5) seizure outcomes in patients with ACC versus those with one-stage TCC. Ten patients with ACC and 14 patients with one-stage TCC met the inclusion criteria. The period for returning home with full ADL recovery was a median of 15 days (range 9−45 days) after ACC, while the median was 21.5 days (range 10−62 days) after one-stage TCC (p = 0.2904). Although there was a tendency for the ADL recovery period to be longer after one-stage TCC, there were no statistically significant differences in any category of ADL recovery period. Eleven of 14 (78.6 %) patients who received a one-stage TCC showed favorable seizure outcomes, with drop attack cessation, which was significantly better than 1 of 10 (10 %) patients with ACC (p = 0.0009). From the viewpoint of postoperative seizure outcomes and ADL recovery period, one-stage TCC is preferred to ACC for adolescent and young adults with severe mental retardation. [ABSTRACT FROM AUTHOR]

• Some patients experience a switch from diurnal to predominantly nocturnal seizures after surgery. • Once established, it is unusual for a nocturnal seizure pattern to revert back to diurnal seizures. • The nocturnal group was older and had a later age of seizure onset. • Half the sample were confirmed as driving, a major contributor to quality of life. To describe the characteristics of a patient group who, after temporal lobectomy for predominantly diurnal seizures, experience a postoperative conversion from diurnal to predominantly nocturnal seizures, and compare this group to those who continue to have a diurnal seizure pattern postoperatively. From a cohort of 470 surgical cases with long-term follow-up, we retrospectively identified 16 patients with a predominantly nocturnal seizure pattern, including five with nocturnal seizures only (median follow-up 21 years) and compared them with 20 predominantly diurnal seizure patients. Sustained postoperative improvement in seizure frequency was observed in 14/16 cases. Seizure recurrence after surgery occurred within the first postoperative year in 13/16 cases. In all but 3 cases the seizures were all predominantly nocturnal from the time of recurrence, whereas in 3 there was a period of diurnal seizures during the early postoperative years. One patient lapsed back to diurnal seizures after 16 years of predominantly nocturnal seizures. Compared to the predominantly diurnal group, these patients had a significantly later age at seizure onset and were older at the time of surgery. Patients with predominantly nocturnal seizures comprise a small but distinct post-operative outcome category. Although not formally assessed, this outcome appears associated with improved quality of life, such as with eligibility to drive, with 50% of the sample confirmed as driving. This finding may help with providing prognostic information and counseling to these patients when they are identified postoperatively. [ABSTRACT FROM AUTHOR]