Engel Class Research Articles

Frontal lobe epilepsy and mild malformation with oligodendroglial hyperplasia: Further observations on electroclinical and imaging phenotypes, and surgical perspectives.

Mild malformation with oligodendroglial hyperplasia (MOGHE) is a recently described clinicopathologic entity, associated with drug-resistant epilepsy and extensive epileptogenic networks. Knowledge is accumulating about particular electroclinical phenotypes, correlations with imaging, and potential prognostic significance for surgical outcomes. The study adds relevant information by documenting the presence of a hyperkinetic frontal lobe seizure phenotype in adolescents and an epileptic encephalopathy phenotype in young children. Five cases were subjected to a structured presurgical evaluation protocol, including EEG-FMRI, chronic and acute invasive EEG, subjected to frontal lobe surgery with postoperative follow-up between 15 months and 7 years. In the two adult cases, surface EEG demonstrated lateralized widespread frontal lobe epileptogenicity and hyperkinetic semiological features. MRI demonstrated cortical white matter blurring and deeper white matter abnormalities. EEG-FMRI suggested concordant frontal lobe involvement. iEEG demonstrated a widespread frontal lobe epilepsy network. The three young children demonstrated a diffuse epileptic encephalopathy phenotype, with nonlocalizing, nonlateralizing surface EEG, and "spasms" as the main seizure type. MRI demonstrated extensive frontal lobe subcortical gray and white matter abnormalities, consistent with MOGHE literature for this age, while EEG-FMRI, in 2/3, demonstrated concordant frontal lobe involvement. They did not undergo chronic iEEG, and the resection was assisted by acute intraoperative ECoG. All cases were subjected to extensive frontal lobectomies with Engel class IA (2/5), IB (1/5), and IIB (2/5) outcomes. The study confirms the presence of frontal lobe epilepsy and epileptic encephalopathy phenotypes, in accordance with epilepsy phenotypes already described in MOGHE literature. Presurgical evaluation studies, including EEG-FMRI, can provide strong lateralizing and localizing evidence of the epileptogenic networks involved. All responded favorably to extensive frontal lobe resections, despite widespread epileptic activity recorded by surface and intracranial EEG pre- and postoperatively; an epileptic encephalopathy phenotype, in the first years of life, should not discourage such a resection.

An Initial Experience of Completion Hemispherotomy via Magnetic Resonance-Guided Laser Interstitial Therapy

Introduction: In carefully selected patients with medically refractory epilepsy, disconnective hemispherotomy can result in significant seizure freedom; however, incomplete disconnection can result in ongoing seizures and poses a significant challenge. Completion hemispherotomy provides an opportunity to finish the disconnection. We describe the use of magnetic resonance-guided laser interstitial thermal ablation (MRgLITT) for completion hemispherotomy. Methods: Patients treated with completion hemispherotomy using MRgLITT at our institution were identified. Procedural and seizure outcomes were evaluated retrospectively. Results: Five patients (3 males) underwent six MRgLITT procedures (one child treated twice) for completion hemispherotomy at a median age of 6 years (range 1.8–12.9). Two children had hemimegalencephaly, two had Rasmussen encephalitis, and one had polymicrogyria. All five children had persistent seizures likely secondary to incomplete disconnection after their functional hemispherotomy. The mean time from open hemispherotomy to MRgLITT was 569.5 ± 272.4 days (median 424, range 342–1,095). One patient underwent stereoelectroencephalography before MRgLITT. The mean number of ablation targets was 2.3 ± 0.47 (median 2, range 2–3). The mean length of the procedure was 373 min ± 68.9 (median 374, range 246–475). Four of the five patients were afforded improvement in their neurocognitive functioning and speech performance after ablation, with mean daily seizure frequency at 1 year of 1.03 ± 1.98 (median 0, range 0–5). Two patients achieved Engel Class I outcomes at 1 year after ablation, one was Engel Class III, and two were Engel Class IV. The mean follow-up time was 646.8 ± 179.5 days (median 634, range 384–918). No MRgLITT-related complications occurred. Delayed retreatment (>1 year) occurred in three patients: one child underwent redo ablation and two underwent anatomic hemispherectomy. Conclusion: We have demonstrated the feasibility of a minimally invasive approach for completion hemispherotomy using MRgLITT. Delayed retreatment was needed in three patients; thus, further study of this technique with comparison to other surgical techniques is warranted.

Efficacy of Cannabidiol in Pediatric Patients: Postmarket Experience at a Single Center

AbstractThe purpose of this research was to determine the postmarket efficacy and safety of cannabidiol in pediatric patients with Lennox–Gastaut's syndrome (LGS), Dravet's syndrome (DS), and other drug-resistant epilepsy (DRE). This was a single-center, retrospective cohort study in pediatric patients who received prescription cannabidiol at a single center. The primary outcome was the reduction in seizure frequency of all seizure types as measured by the Engel outcome scale at 3 months after initiation of cannabidiol. Thirty-six patients were included. The most common outcome in all three groups was an Engel Class III outcome 3 months following initiation of cannabidiol. Most patients in all groups experienced some clinical benefit and only 33% of patients experienced no clinical benefit. The maximum tolerated dose of cannabidiol at 3 months ranged from 5 to 31 mg/kg/d with a median of 17.9, 13.2, and 18.0 mg/kg/d in the LGS, DS, and DRE (other) groups, respectively. Eight patients discontinued cannabidiol at 3 months and only two patients were hospitalized after initiation of therapy. Seventy-five percent of patients did not report any adverse side effects. Based on the Engel outcome scale utilized within this study, pediatric patients with LGS, DS, and DRE (other) may experience a worthwhile improvement in seizure frequency while on cannabidiol. Further studies are needed to determine the long-term efficacy and safety of cannabidiol and discern predictors of response to therapy.

Impact of Etiology on Seizure and Quantitative Functional Outcomes in Children with Cerebral Palsy and Medically Intractable Epilepsy Undergoing Hemispherotomy/Hemispherectomy

To compare functional and seizure outcomes in children with vascular and dysplastic etiologies of cerebral palsy and medically intractable epilepsy following functional hemispherotomy or anatomic hemispherectomy. Consecutive patients satisfying inclusion criteria from 07/01/2015 to 12/01/2019 were reviewed for demographic data and seizure (Engel classification) and functional (Functional Independence Measure for Children) outcomes. After a mean follow-up of 2years 8months (1year 2months), 11 of 18 patients achieved post-operative seizure freedom without significant difference between vascular (5/7) and dysplastic (6/11) etiologies (P= 0.64). Functional assessments were completed for 15 of 18 of subjects, split comparably between groups. Mean change in the Functional Independence Measure for Children from pre-operative baseline to inpatient rehabilitation admission (vascular,-35.3 [13.2]; malformation of cortical development{MCD},-34.5 [25.0]; P= 0.69), inpatient rehabilitation admission to discharge (vascular, 18.7 [9.0]; MCD, 20.8 [11.4]; P= 0.60), and pre-operative evaluation to clinic follow-up (vascular,-7.6 [9.7]; MCD,-3.6 [19.3]; P= 0.61) did not differ between groups. Quantitative functional and seizure outcomes following functional hemispherotomy or anatomic hemispherectomy did not differ significantly between vascular and dysplastic etiologies of cerebral palsy and medically intractable epilepsy in this study. Hemispheric surgery resulted in minor functional declines from baseline following comprehensive multidisciplinary therapy.

Mesial temporal lobe epilepsy with amygdalar hamartoma-like lesion: Is it a distinct syndrome?

IntroductionWe examined the clinical, semiological, scalp electroencephalographic (EEG), and neuropsychological features of patients with amygdalar hamartoma-like lesion (AHL) without hippocampal sclerosis (HS). MethodsThis retrospective study included 9 patients with mesial temporal lobe epilepsy (MTLE) who had an amygdalar lesion on preoperative MRI; underwent mesial temporal resection; were diagnosed with amygdalar hamartoma-like lesion (AHL) without hippocampal sclerosis (HS); were followed up for at least 2 years after surgery; and had a favourable postoperative seizure outcome (Engel Class I). There were 5 women and 4 men, and age at surgery ranged from 19 to 54 (mean, 36.6) years. Clinical characteristics, auras, video-recorded seizure semiology, interictal and ictal EEG, and preoperative neuropsychological data were reviewed. Twenty patients with MTLE with HS who had favourable postoperative seizure outcomes (Engel Class I) were selected as controls. ResultsAge at seizure onset was significantly higher in patients with AHL without HS than in those with HS. Fear was more frequently seen in patients with AHL (44 %) than in those with HS (5 %) (P = 0.022). There were no significant differences in interictal epileptiform discharges or ictal EEG pattern. Preoperative full-scale IQ score was significantly higher in the AHL group than in the HS group (mean, 92.9 v. 74.8, P = 0.004), as was preoperative memory quotient score (mean 100.7 v. 85.1, P = 0.028). ConclusionWe clarified the clinical, semiological, and neuropsychological features of patients with MTLE-AHL. These findings may be useful for preoperative evaluation, especially of patients with suspected MTLE but without apparent HS on preoperative MRI.

Metabolic profiles and correlation with surgical outcomes in mesial versus neocortical temporal lobe epilepsy.

Differentiating mesial temporal lobe epilepsy (MTLE) and neocortical temporal lobe epilepsy (NTLE) remains challenging. Our study characterized the metabolic profiles between MTLE and NTLE and their correlation with surgical prognosis using 18 F-FDG-PET. A total of 137 patients with intractable temporal lobe epilepsy (TLE) and 40 age-matched healthy controls were recruited. Patients were divided into the MTLE group (N = 91) and the NTLE group (N = 46). 18 F-FDG-PET was used to measure the metabolism of regional cerebra, which was analyzed using statistical parametric mapping. The volume of abnormal metabolism in cerebral regions and their relationship with surgical prognosis were calculated for each surgical patient. The cerebral hypometabolism of MTLE was limited to the ipsilateral temporal and insular lobes (p < 0.001, uncorrected). The NTLE patients showed hypometabolism in the ipsilateral temporal, frontal, and parietal lobes (p < 0.001, uncorrected). The MTLE patients showed extensive hypermetabolism in cerebral regions (p < 0.001, uncorrected). Hypermetabolism in NTLE was limited to the contralateral temporal lobe and cerebellum, ipsilateral frontal lobe, occipital lobe, and bilateral thalamus (p < 0.001, uncorrected). Among patients who underwent resection of epileptic lesions, 51 (67.1%) patients in the MTLE group and 10 (43.5%) in the NTLE group achieved Engel class IA outcome (p = 0.041). The volumes of metabolic increase for the frontal lobe or thalamus in the MTLE group were larger in non-Engel class IA patients than Engel class IA patients (p < 0.05). The spatial metabolic profile discriminated NTLE from MTLE. Hypermetabolism of the thalamus and frontal lobe in MTLE may facilitate preoperative counseling and surgical planning.

Cavernoma-Related Epilepsy: Postoperative Epilepsy Outcome and Analysis of the Predictive Factors, Case Series.

Epilepsy is common in patients harboring cavernous malformation, and surgery is reported to be an effective treatment. However, few patients still experience seizures after surgery. We analyzed the outcome and predictive factors after cavernoma-related epilepsy (CRE) surgery. A database was created for all patients with CRE treated surgically from 2003 to 2020 at a university hospital. A chart review, perioperative epilepsy workup, surgical strategies, and postoperative and follow-up notes were analyzed. Postoperative seizure outcome was evaluated according to the Engel classification. Thirty-seven patients (40.5% women; mean age 39.1 ± 14.5 years) were studied. The mean follow-up time was 5.6 ± 3.9 years. Among 37 patients, 32 (86.5%) achieved Engel class I at the last follow-up. Engel class II was found in 1 (2.7%), Engel class III in 1 (2.7%), and Engel class IV in 3 (8.1%) cases. Engel class Ia was observed in 23 patients (62.2%). None of the patients had a worse seizure outcome after the operation (Engel class IVc). Univariate and multivariate analysis showed that short-standing, sporadic, or low-frequent (≤3) seizures were the only variables significantly associated with seizure freedom, whereas longstanding, drug-resistant, or high-frequent seizure history were associated with worse seizure outcomes. Surgical treatment results in favorable seizure control in most patients after CRE surgery. Long duration of epilepsy before surgery, high seizure frequency, and drug-resistant epilepsy could have a negative effect on seizure outcome (Engel class II-IV). Therefore, early surgical resection of the cavernoma after careful presurgical planning is recommended to achieve an optimal result.

Outcome Predictors of Lesional Posterior Cortex Epilepsy Surgery.

Lesional posterior cortex epilepsy (PCE) is often drug resistant and may benefit from surgical intervention. In this study, we aimed to identify potential predictive factors associated with seizure recurrence after epilepsy surgery in lesional PCE. We retrospectively reviewed patients with PCE who underwent surgery between 1998 and 2021. They were divided into 2 groups according to seizure outcome; the seizure-free group (group 1) and the non-seizure-free group (group 2). The relationship among clinical factors, electroencephalography (EEG) or cranial magnetic resonance imaging findings, disease, and seizure outcome was investigated. A total of 60 patients, with a mean age of 27.26 ± 12.35 years (range, 9-61 years), were included in the study. There were 31 patients (51.66%) in group 1 (Engel class I) and 29 patients (48.33%) in group 2 (13 [21.66%], 10 [16.66%], and 6 [10%] patients in Engel class II, III, and IV, respectively), with a mean follow-up of 8.95 ± 6.96 years (range, 1-24 years). No difference was observed regarding age, gender, age at seizure onset, operation type, treatment gap, and presence of bilateral lesions between the groups (P > 0.05). However, bilateral findings on interictal EEG and gliosis as the underlying disease were predictors of seizure recurrence (P < 0.05). More than half of the patients (including 2 with bilateral magnetic resonance imaging lesions) were seizure free at long-term follow-up. However, patients with bilateral findings on interictal EEG and gliosis were more likely to have recurrent seizures after surgery. Because lesional PCE is almost always drug resistant and has a potential for favorable outcomes, epilepsy surgery should be considered early.

Long-term seizure outcome with the surgically remediable syndrome of frontal lobe epilepsy associated with superior frontal sulcus-related dysplasia.

To assess the long-term outcome of the surgically remediable syndrome of frontal lobe epilepsy (FLE) associated with superior frontal sulcus (SFS)-related dysplasia. We retrospectively reviewed the medical charts and surgical features of 31 patients with drug-resistant frontal lobe epilepsy in our centers between 2016 and 2018. All patients underwent surgical resection. According to the epileptogenic zone (EZ), localization and resection extent were classified as (1) pure SFS group (PS group), (2) associated SFS group (AS group), and (3) no SFS group (NS group). The general characteristics, neuroradiological findings, morbidity, pathology, and long-term seizure outcome after surgery were analyzed to extract the potential value of the surgery for SFS-related dysplasia. Of 31 patients with FLE who underwent epilepsy surgery, 15 patients (nine men) were included PS group, five patients (five men) in the AS group, and 11 patients (eight men) in the NS group. Eleven patients detected abnormal focal signals in the presurgical MRI. Six patients in the PS group demonstrated the suspected focal cortical dysplasia (FCD) in the SFS detected with MRI. All patients demonstrated focal abnormal hypometabolism foci in the PET-MR co-registration. Twenty-five patients (80.6%) were seizure-free since surgery, including all 15 patients (100%) of the PS group, three in five patients (60%) of the AS group, and seven in 11 patients (63.6%) of the NS group. The difference in outcome between different groups was significant (p = 0.004, PS vs. AS group; p = 0.005, PS vs. NS group). As of the last follow-up (mean 66.2 ± 9.7months), 25 patients (80.6%) were seizure-free since surgery (Engel's class I). In addition, antiseizure medication was withdrawn in 19 patients (61.3%). Histologic examination of resected specimens revealed FCD in all 31 patients. The percentage of FCD II type was 100, 60, and 63.6% in the three different groups, respectively. SFS-related dysplasia is a neuropathologic entity with a favorable postoperative outcome. FCD II is the most common type of SFS-related dysplasia. FDG-PET co-registered with MRI should be performed in patients with suspected SFS-related dysplasia, since it may depict areas of hypometabolism suggestive of dysplasia in the absence of MRI abnormalities.

Stereo-electroencephalography (SEEG)-Guided Surgery in Epilepsy With Cingulate Gyrus Involvement: Electrode Implantation Strategies and Postoperative Seizure Outcome.

Surgical treatment of cingulate gyrus epilepsy is associated with good results on seizures despite its rarity and challenging aspects. Invasive EEG monitoring is often mandatory to assess the epileptogenic zone in these patients. To date, only small surgical series have been published, and a consensus about management of these complex cases did not emerge. The authors retrospectively analyzed a large surgical series of patients in whom at least part of the cingulate gyrus was confirmed as included in the epileptogenic zone by means of stereo-electroencephalography and was thus resected. One hundred twenty-seven patients were selected. Stereo-electroencephalography-guided implantation of intracerebral electrodes was performed in the right hemisphere in 62 patients (48.8%) and in the left hemisphere in 44 patients (34.7%), whereas 21 patients (16.5%) underwent bilateral implantations. The median number of implanted electrodes per patient was 13 (interquartile range 12-15). The median number of electrodes targeting the cingulate gyrus was 4 (interquartile range 3-5). The cingulate gyrus was explored bilaterally in 19 patients (15%). Complication rate was 0.8%. A favorable outcome (Engel class I) was obtained in 54.3% of patients, with a median follow-up of 60 months. The chance to obtain seizure freedom increased in cases in whom histologic diagnosis was type-IIb focal cortical dysplasia or tumor (mostly ganglioglioma or dysembryoplastic neuroepithelial tumor) and with male gender. Higher seizure frequency predicted better outcome with a trend toward significance. Our findings suggest that stereo-electroencephalography is a safe and effective methodology in achieving seizure freedom in complex cases of epilepsy with cingulate gyrus involvement.

Epilepsy surgery for dominant-side mesial temporal lobe epilepsy without hippocampal sclerosis

Although anterior temporal lobectomy (ATL) is an established surgery for medically intractable mesial temporal lobe epilepsy (MTLE), it can harm memory function, especially in dominant-side MTLE patients without hippocampal sclerosis (HS). To avoid this complication, multiple hippocampal transection (MHT) was developed, but its efficacy has not been fully elucidated. We report the detailed treatment results of MHT compared with that of ATL. We retrospectively analysed the records of 30 patients who underwent surgery for dominant-side MTLE. ATL was completed for 23 patients with HS, and MHT was completed for 7 patients without HS. The seizure control status, number of anti-seizure medicines, neurocognitive function, and psychiatric disorders of each patient were reviewed. The mean follow-up period was 70 months. Seizure control of Engel class I was achieved in 16 patients (70%) in the ALT group versus 5 patients (71%) in the MHT group. The mean number of anti-seizure medicines administered in the ATL group changed significantly from 2.4 to 1.9 (p = 0.01), while that in the MHT group was unchanged (from 2.1 to 2.0, p = 0.77). Eleven patients (48%) in the ATL group developed psychiatric disorders during the postoperative follow-up period, whereas no psychological complications were observed in the MHT group. Neither group showed neurocognitive decline after the surgery in any of the WAIS-III or WMS-R subtests. In conclusion, MHT may achieve reasonable postoperative seizure reduction, preserve neurocognitive function, and reduce postoperative psychiatric complications. Therefore, it can be considered as a therapeutic option for dominant-side MTLE without HS.

Prognostic analysis in children with focal cortical dysplasia II undergoing epilepsy surgery: Clinical and radiological factors.

The aim of this study was to investigate the value of clinical profiles and radiological findings in assessing postsurgical outcomes in children with focal cortical dysplasia (FCD) II while exploring prognostic predictors of this disease. We retrospectively reviewed 50 patients with postoperative pathologically confirmed FCD II from January 2016 to June 2021. The clinical profiles and preoperative radiological findings were measured and analyzed. The patients were classified into four classes based on the Engel Class Outcome System at the last follow-up. For the analysis, the patients were divided into two categories based on Engel I and Engel II-IV, namely, seizure-free and non-seizure-free groups. Qualitative and quantitative factors were subsequently compared by groups using comparative statistics. Receiver operating characteristic (ROC) curves were used to identify the predictors of prognosis in children with FCD II. Thirty-seven patients (74%) had Engel class I outcomes. The minimum postsurgical follow-up was 1 year. At the epilepsy onset, patients who attained seizure freedom were older and less likely to have no apparent lesions on the preoperative MRI ("MRI-negative"). The non-seizure-free group exhibited a higher gray matter signal intensity ratio (GR) on 3D T1-MPRAGE images (p = 0.006), with a lower GR on T2WI images (p = 0.003) and FLAIR images (p = 0.032). The ROC curve indicated that the model that combined the GR value of all MRI sequences (AUC, 0.87; 95% CI, 0.77-0.97; p < 0.001; 86% sensitivity, 85% specificity) was able to predict prognosis accurately. A lower age at the onset or the MRI-negative finding of FCD lesions suggests a poor prognosis for children with FCD II. The model consisting of GR values from three MRI sequences facilitates the prognostic assessment of FCD II patients with subtle MRI abnormalities to prevent worse outcomes.

Magnetic resonance imaging-guided stereotactic laser ablation therapy for the treatment of pediatric epilepsy: a retrospective multiinstitutional study.

The authors of this study evaluated the safety and efficacy of stereotactic laser ablation (SLA) for the treatment of drug-resistant epilepsy (DRE) in children. Seventeen North American centers were enrolled in the study. Data for pediatric patients with DRE who had been treated with SLA between 2008 and 2018 were retrospectively reviewed. A total of 225 patients, mean age 12.8 ± 5.8 years, were identified. Target-of-interest (TOI) locations included extratemporal (44.4%), temporal neocortical (8.4%), mesiotemporal (23.1%), hypothalamic (14.2%), and callosal (9.8%). Visualase and NeuroBlate SLA systems were used in 199 and 26 cases, respectively. Procedure goals included ablation (149 cases), disconnection (63), or both (13). The mean follow-up was 27 ± 20.4 months. Improvement in targeted seizure type (TST) was seen in 179 (84.0%) patients. Engel classification was reported for 167 (74.2%) patients; excluding the palliative cases, 74 (49.7%), 35 (23.5%), 10 (6.7%), and 30 (20.1%) patients had Engel class I, II, III, and IV outcomes, respectively. For patients with a follow-up ≥ 12 months, 25 (51.0%), 18 (36.7%), 3 (6.1%), and 3 (6.1%) had Engel class I, II, III, and IV outcomes, respectively. Patients with a history of pre-SLA surgery related to the TOI, a pathology of malformation of cortical development, and 2+ trajectories per TOI were more likely to experience no improvement in seizure frequency and/or to have an unfavorable outcome. A greater number of smaller thermal lesions was associated with greater improvement in TST. Thirty (13.3%) patients experienced 51 short-term complications including malpositioned catheter (3 cases), intracranial hemorrhage (2), transient neurological deficit (19), permanent neurological deficit (3), symptomatic perilesional edema (6), hydrocephalus (1), CSF leakage (1), wound infection (2), unplanned ICU stay (5), and unplanned 30-day readmission (9). The relative incidence of complications was higher in the hypothalamic target location. Target volume, number of laser trajectories, number or size of thermal lesions, or use of perioperative steroids did not have a significant effect on short-term complications. SLA appears to be an effective and well-tolerated treatment option for children with DRE. Large-volume prospective studies are needed to better understand the indications for treatment and demonstrate the long-term efficacy of SLA in this population.

Asymmetry index in anatomically symmetrized FDG-PET for improved epileptogenic focus detection in pharmacoresistant epilepsy.

Positron emission tomography (PET) imaging has assumed an essential role in the presurgical evaluation of epileptogenic foci in drug-resistant epilepsy by identifying the hypometabolic cerebral cortex. The authors herein designed a pilot study to test a novel technique of PET asymmetry after anatomical symmetrization coregistered to MRI (PASCOM), utilizing interhemispheric metabolic asymmetry on interictal fluorine 18-labeled fluorodeoxyglucose (FDG)-PET to better localize the epileptogenic zone. The authors analyzed interictal FDG-PET scans from 23 patients with drug-resistant epilepsy, mean (± SD) age 20.9 ± 13.1 years old, who had an Engel class I postsurgical outcome while followed up for > 12 months. T1-weighted and FLAIR MRI were used to create a patient-specific, structurally symmetrical template. The asymmetry index (AI) image was computed to detect the cerebral region of hypometabolism using different z-score threshold criteria to optimize sensitivity and specificity. The detected regions were compared with the resection cavity on postoperative MRI using predefined anatomical labels. PASCOM was compared with the visual analysis of FDG-PET by a nuclear medicine consultant blinded to other clinical data (VIS) and visual analysis during multidisciplinary team discussion (MDT). The efficacy of each technique was compared based on a performance score (S), sensitivity, specificity, and correct lateralization of epileptogenicity. The mean S was maximum (1.30 ± 1.23) for AI images when thresholded at z > 4 and retaining the cluster of more than 100 voxels containing the peak AI value (Z4C) with 73.03% sensitivity and 96.43% specificity. The mean S was minimum for VIS (0.27 ± 0.31). The mean sensitivity was maximum for MDT (85.04%) and minimum for Z5C (AI images thresholded at z > 5 and clustered; 59.47%), whereas the mean specificity was maximum for Z5C (97.77%) and minimum for VIS (64.60%). Z3C (AI images thresholded at z > 3 and clustered) and Z4C were able to correctly identify the side of epileptogenicity in all the patients. The PASCOM technique with a Z4C threshold had a maximum performance score with good sensitivity and specificity in localizing and lateralizing the epileptogenic zone. The described technique outperformed the conventional visual analysis of FDG-PET and hence warrants further prospective verification.

Stereoelectroencephalography followed by combined electrode removal and MRI-guided laser interstitial thermal therapy or open resection: a single-center series in pediatric patients with medically refractory epilepsy.

Stereoelectroencephalography (SEEG) and MRI-guided laser interstitial thermal therapy (MRgLITT) have emerged as safe, effective, and less invasive alternatives to subdural grid placement and open resection, respectively, for the localization and treatment of medically refractory epilepsy (MRE) in children. Reported pediatric experience combining these complementary techniques is limited, with traditional workflows separating electrode removal and ablation/resection. The authors describe the largest reported series of pediatric epilepsy patients who underwent MRgLITT following SEEG contrasted with a cohort that underwent craniotomy following SEEG, combining ablation/resection with electrode explantation as standard practice. The medical records of all patients with MRE who had undergone SEEG followed by MRgLITT or open resection/disconnection at Boston Children's Hospital between November 2015 and December 2020 were retrospectively reviewed. Primary outcome variables included surgical complication rates, length of hospital stay following treatment, and Engel classification at the last follow-up. Of 74 SEEG patients, 27 (median age 12.1 years, 63% female) underwent MRgLITT and 47 (median age 12.1 years, 49% female) underwent craniotomy. Seventy patients (95%) underwent SEEG followed by combined electrode removal and treatment. Eight MRgLITT cases (30%) and no open cases targeted the insula (p < 0.001). Complication rates did not differ, although trends toward more subdural/epidural hematomas, infarcts, and permanent unanticipated neurological deficits were evident following craniotomy, whereas a trend toward more temporary unanticipated neurological deficits was seen following MRgLITT. The median duration of hospitalization after treatment was 3 and 5 days for MRgLITT and open cases, respectively (p = 0.078). Seizure outcomes were similar between the cohorts, with 74% of MRgLITT and craniotomy patients attaining Engel class I or II outcomes (p = 0.386) at the last follow-up (median 1.1 and 1.9 years, respectively). MRgLITT and open resection following SEEG can both effectively treat MRE in pediatric patients and generally can be performed in a two-surgery workflow during a single hospitalization. In appropriately selected patients, MRgLITT tended to be associated with shorter hospitalizations and fewer complications following treatment and may be best suited for focal deep-seated targets associated with relatively challenging open surgical approaches.

Diagnostic Accuracy of Epilepsy-dedicated MRI with Post-processing

PurposeTo evaluate the diagnostic accuracy of epilepsy-dedicated 3 Tesla MRI including post-processing by correlating MRI, histopathology, and postsurgical seizure outcomes.Methods3 Tesla-MRI including a magnetization-prepared two rapid acquisition gradient echo (MP2RAGE) sequence for post-processing using the morphometric analysis program MAP was acquired in 116 consecutive patients with drug-resistant focal epilepsy undergoing resection surgery. The MRI, histopathology reports and postsurgical seizure outcomes were recorded from the patient’s charts.ResultsThe MRI and histopathology were concordant in 101 and discordant in 15 patients, 3 no hippocampal sclerosis/gliosis only lesions were missed on MRI and 1 of 28 focal cortical dysplasia (FCD) type II associated with a glial scar was considered a glial scar only on MRI. In another five patients, MRI was suggestive of FCD, the histopathology was uneventful but patients were seizure-free following surgery. The MRI and histopathology were concordant in 20 of 21 glioneuronal tumors, 6 cavernomas, and 7 glial scars. Histopathology was negative in 10 patients with temporal lobe epilepsy, 4 of them had anteroinferior meningoencephaloceles. Engel class IA outcome was reached in 71% of patients.ConclusionThe proposed MRI protocol is highly accurate. No hippocampal sclerosis/gliosis only lesions are typically MRI negative. Small MRI positive FCD can be histopathologically missed, most likely due to sampling errors resulting from insufficient harvesting of tissue.

Pediatric epilepsy surgery in patients with Lennox-Gastaut syndrome after viral encephalitis.

To analyse the surgical outcomes of pediatric patients with Lennox-Gastaut syndrome (LGS) secondary to viral encephalitis. We retrospectively analyzed the data of four patients with LGS secondary to viral encephalitis who underwent surgery at the pediatric epilepsy center of Peking University First Hospital from January 2014 to December 2019. Preoperative evaluations included a detailed history, long-term video electroencephalography (VEEG), brain magnetic resonance imaging (MRI), positron emission tomography (PET) and a neuropsychological test. All patients were followed up at 1, 3, and 6 months and then yearly. The surgical outcome was evaluated according to the Engel classification. Among the four children, the surgeries were right temporo-parieto-occipital disconnection (case 1), corpus callosotomy (case 2), left temporo-parieto-occipital disconnection (case 3), and left temporal lobectomy (case 4). The pathology was gliosis secondary to viral encephalitis. The median follow-up time was 4 years (3-5 years). At the last follow-up, one case had Engel I, two cases had Engel III, and one case had Engel IV. Preliminary observations shows that surgical treatment may be challenging for patients with LGS secondary to viral encephalitis. However, suitable surgical candidacy and approaches have a significant impact on the prognosis of the patients.

Hippocampal volumetry to determine the resection side in patients with intractable non-lesional bilateral temporal lobe epilepsy

Bilateral Temporal lobe epilepsy (BTLE) cases may result in poor surgical outcomes due to the difficulty in determining/localizing the epileptogenic zone. In this study, we investigated whether hippocampal volume (HV) would be useful for the determination of the best resection side in BTLE. Eighteen cases of BTLE determined by a scalp video electroencephalogram (SVEEG) underwent resection via intracranial electroencephalography (IVEEG). Patients with lesions or semiologically determined focus lateralization were excluded. In addition to SVEEG, an epilepsy protocol magnetic resonance imaging (MRI) including hippocampus fluid-attenuated inversion recovery (FLAIR) and HV, 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), single-photon emission computed tomography with 123I-iomazenil (IMZ-SPECT), and magnetoencephalography (MEG) were performed for the preoperative evaluation of the lateralization. The resection side was determined based on the IVEEG results, and the seizure outcome at two years postoperatively was classified as either a well-controlled seizure outcome (Engel class I), or residual (classes II–V). We used a Fisher's exact test to compare the concordance between the determination of the epileptic focus by each modality and the resected side where patients achieved a well-controlled seizure outcome. Seizures were well controlled in 9/18 patients after surgery. Eight out of 11 patients (72.7%), in whom the HV results (strongly atrophic side) and the resection side were matched, had well-controlled seizure outcomes (P = 0.0498). The concordance of other presurgical evaluations with the resection side was not significantly related to a well-controlled seizure outcome. HV may be a useful method to determine the optimal resection side of the epileptic focus/foci in cases of suspected BTLE.

Physician distress when treatments fail. Survey on physician distress when treating persons with drug-resistant epilepsy and knowledge of neuropalliative care

ObjectiveDrug-resistant epilepsy can be difficult to cure and may pose emotional challenges for epilepsy providers. Neuropalliative care (NPC) can augment quality of life (QOL) in persons with neurological diseases and may add meaningful elements to the treatment repertoire of epilepsy specialists even if seizures continue. However, NPC has not been widely implemented in epilepsy. Our study aimed to determine whether physicians of persons with drug-resistant epilepsy (PWDRE) experience distress when faced with treatment failure (Engel class ≥ 2), either failure of medications-only (PWDREmo) or of both medications and surgery (procedures with curative intent (PWDREms)). Furthermore, we evaluated physician knowledge about and referrals to NPC following treatment failures to help improve patient QOL despite ongoing seizures. MethodsAn anonymous online survey was distributed to US epilepsy physicians through the American Epilepsy Society website and personal email to assess levels of distress experienced when caring for PWDREmo and PWDREms (7-point Likert scale [“1” = “no distress”, “7” = “most distress ever felt”]), and knowledge and use of NPC. ResultsEighty-two physicians completed the survey. Most experienced distress when epilepsy treatments failed: 59% felt moderate distress (≥4) with PWDREmo (median “4”, mean 3.74, range 1–7), 90% suffered moderate to severe distress (5, 5.17, 1–7) with PWDREms. Distress over PWDREms was significantly greater than distress over PWDREmo (p < 0.0001). Forty-three percent reported confidence in their knowledge about NPC. Only 15% were likely to refer PWDREmo to NPC, while 44% would consider it for PWDREms. ConclusionAmong survey responders, physician distress was high when confronted with treatment failures, especially the failure of epilepsy surgery. Fewer than half of responders were likely to refer patients to NPC. Further research is necessary to determine extent, reasons, and effects of physician distress and whether improved understanding of and patient access to NPC would help alleviate physician distress when faced with treatment failures in PWDRE.

Functional outcomes of pediatric hemispherotomy: Impairment, activity, and medical service utilization

ObjectiveThe purpose of this study was to describe the functional outcomes of hemispherotomy in a pediatric cohort, including impairments, activity limitations, utilization of therapies and medical specialist services, and subsequent surgical intervention. MethodsWe conducted a retrospective review of patients who underwent hemispherotomy at UPMC Children’s Hospital of Pittsburgh from 2001 to 2021. Data on impairments, activity limitations in mobility, self-care, and communication, and use of re/habilitative therapies and medical specialist services were collected pre-operatively and at 1, 5, 10, and 15 years postoperatively. Seizure outcomes were reported via Engel classification at the longest follow-up interval and subsequent surgical procedures were documented through the latest follow-up interval. ResultsA total of 28 patients who underwent hemispherotomy were assessed prior to surgery, 26 at 1 year post-op, 13 at 5 years, 9 at 10 years, and 5 at 15 years. Seizure outcomes at the longest follow-up interval showed that 84.6% of patients were seizure-free. Assessment of impairments to body structure & function from baseline to 1-year post-op revealed increased impairment in 73% of patients, while most patients saw no change in impairment at 5 years (69%), 10 years (100%), and 15 years (100%) post-op compared to the previous time point. Muscle tone abnormalities (100%), hemiparesis (92%), and visual field deficits (85%) were the most frequently observed impairments in the first year following surgery. Most patients saw no change in developmental or cognitive-affective impairments at 1 (65%), 5 (85%), 10 (89%), and 15 years (80%) post-op compared to the previous time point. The only qualitative reports of decreased ability occurred in 2/26 patients whose medical records indicated decreased mobility at the 1-year mark. All further qualitative reports of ability in mobility, self-care, and communication domains indicated increases or no change in ability for all patients at each of the subsequent follow-up intervals. Exploration of the utilization of re/habilitative therapy services shows that 84% of patients received at least one therapy service at baseline, 100% at1 year, 92% at 5 years, 100% at 10 years, and 80% at 15 years post-op. Patients were followed, on average (m), by multiple medical specialist services at baseline (m = 2.58) as well as the 1- (m = 1.70), 5- (m = 2.15), 10- (m = 3.00) and 15-year (m = 3.40) follow-up intervals. Following hemispherotomy, 15 (53.6%) patients required an average of 2.21 additional surgeries. Most often required was orthopedic surgical intervention (n = 16 procedures), followed by shunt placement (n = 7) and revision (n = 14) targeting hydrocephalus. SignificanceThis retrospective study demonstrates expected increases in impairments such as hemiparesis and visual field deficits (i.e., homonymous hemianopia) in the context of increased activity and favorable seizure outcomes for 28 pediatric patients who underwent hemispherotomy for drug-resistant epilepsy. Most patients required rehabilitative therapies prior to surgery and continued to require these services post-operatively. Reported baseline functional status, the persistence of impairments following surgery, and comorbidities among this cohort underscore the medical complexity of this patient population and the importance of multidisciplinary care both pre-and post-operatively.