Fifty Consecutive Hemispherectomies

Abstract BACKGROUND: Techniques for achieving hemispheric disconnection in patients with epilepsy continue to evolve. OBJECTIVE: To review the outcomes of the first 50 hemispherectomy surgeries performed by a single surgeon with an emphasis on outcomes, complications, and how these results led to changes in practice. METHODS: The first 50 hemispherectomy cases performed by the lead author were identified from a prospectively maintained database. Patient demographics, surgical details, clinical outcomes, and complications were critically reviewed. RESULTS: From 2004 to 2012, 50 patients underwent hemispherectomy surgery (mean follow-up time, 3.5 years). Modified lateral hemispherotomy became the preferred technique and was performed on 44 patients. Forty patients (80%) achieved complete seizure freedom (Engel I). Presurgical and postsurgical neuropsychological evaluations demonstrated cognitive stability. Two cases were performed for palliation only. Previous hemispherectomy surgery was associated with worsened seizure outcome (2 of 6 seizure free; P .005). The use of Avitene was associated with a higher incidence of postoperative hydrocephalus (56% vs 18%; P = .03). In modified lateral hemispherotomy patients without the use of Avitene, the incidence of hydrocephalus was 13%. Complications included infection (n = 3), incomplete disconnection requiring reoperation (n = 1), reversible ischemic neurological deficit (n = 1), and craniosynostosis (n = 1). There were no (unanticipated) permanent neurological deficits or deaths. Minor technique modifications were made in response to specific complications. CONCLUSION: The modified lateral hemispherotomy is effective and safe for both initial and revision hemispherectomy surgery. Avitene use appears to result in a greater incidence of postoperative hydrocephalus.

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Seizure outcome and complications following hypothalamic hamartoma treatment in adults: endoscopic, open, and Gamma Knife procedures

Journal of Neurosurgery ◽

10.3171/2012.5.jns112256 ◽

2012 ◽

Vol 117 (2) ◽

pp. 255-261 ◽

Cited By ~ 36

Author(s):

Cornelia Drees ◽

Kevin Chapman ◽

Erin Prenger ◽

Leslie Baxter ◽

Rama Maganti ◽

...

Keyword(s):

Mental Retardation ◽

Weight Gain ◽

Gamma Knife ◽

Third Ventricle ◽

Intractable Epilepsy ◽

Adult Patients ◽

Neurological Deficits ◽

Hypothalamic Hamartoma ◽

Seizure Outcome ◽

Seizure Freedom

Object This study aimed at identifying outcomes with respect to seizures, morbidity, and mortality in adult patients undergoing resective or Gamma Knife surgery (GKS) to treat intractable epilepsy associated with hypothalamic hamartoma (HH). Methods Adult patients undergoing surgical treatment for HH-related epilepsy were prospectively monitored at a single center for complications and seizure outcome by using a proprietary database. Preintervention and postintervention data for patients 18 years of age and older, and with at least 1 year of follow-up, were analyzed, with specific attention to seizure control, complications, hormonal status, and death. Results Forty adult patients were found in the database (21 were women). The median HH volume was 0.54 cm3. In 70% of patients, it was located inside the third ventricle, attached unilaterally and vertically to the hypothalamus (Delalande Type II). Most patients (26) underwent an endoscopic resection, 10 patients had a transcallosal or other type of open (pterional or orbitozygomatic) resection, and 4 patients chose GKS. Twenty-nine percent became seizure free in the long term, and overall a majority of patients (55%) reported at least > 90% seizure improvement. Only 3 patients were ultimately able to discontinue anticonvulsants, whereas most patients were taking an average of 2 antiepileptic drugs pre- and postoperatively. The only factor significantly correlated with seizure-free outcome was the absence of mental retardation. The HH volume, HH type, and amount of resection or disconnection were not correlated to seizure freedom. A total of 4 patients (10%) died, 2 immediately after surgery and 2 later. All of them had undergone a resection, as opposed to GKS, and still had seizures. Postoperatively, persistent neurological deficits were seen in 1 patient; 34% of patients had mild hormonal problems; and 59% experienced weight gain of at least 6.8 kg (average gain 12.7 kg). Conclusions Surgical or GKS procedures in adults with HH provided seizure freedom in one-third of patients. The only significant favorable prognostic factor was the absence of mental retardation. The overall mortality rate was high, at 10%. Other important morbidities were persistent hormonal disturbances and weight gain.

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Multiple Subpial Transections for Medically Refractory Epilepsy: A Disaggregated Review of Patient-Level Data

Neurosurgery ◽

10.1093/neuros/nyx311 ◽

2017 ◽

Vol 82 (5) ◽

pp. 613-620 ◽

Cited By ~ 10

Author(s):

John D Rolston ◽

Hansen Deng ◽

Doris D Wang ◽

Dario J Englot ◽

Edward F Chang

Keyword(s):

Confidence Interval ◽

Odds Ratio ◽

Refractory Epilepsy ◽

Seizure Type ◽

Seizure Outcome ◽

Seizure Freedom ◽

Patient Level Data ◽

Patient Demographics ◽

Patient Level ◽

Level Data

Abstract BACKGROUND Multiple subpial transections (MST) are a treatment for seizure foci in nonresectable eloquent areas. OBJECTIVE To systematically review patient-level data regarding MST. METHODS Studies describing patient-level data for MST procedures were extracted from the Medline and PubMed databases, yielding a synthetic cohort of 212 patients from 34 studies. Data regarding seizure outcome, patient demographics, seizure type, surgery type, and complications were extracted and analyzed. RESULTS Seizure freedom was achieved in 55.2% of patients undergoing MST combined with resection, and 23.9% of patients undergoing MST alone. Significant predictors for seizure freedom were a temporal lobe focus (odds ratio 4.9; 95% confidence interval 1.71, 14.3) and resection of portions of the focus, when feasible (odds ratio 3.88; 95% confidence interval 2.02, 7.45). Complications were frequent, with transient mono- or hemiparesis affecting 19.8% of patients, transient dysphasia 12.3%, and permanent paresis or dysphasia in 6.6% and 1.9% of patients, respectively. CONCLUSION MST is an effective treatment for refractory epilepsy in eloquent cortex, with greater chances of seizure freedom when portions of the focus are resected in tandem with MST. The reported rates of seizure freedom with MST are higher than those of existing neuromodulatory therapies, such as vagus nerve stimulation, deep brain stimulation, and responsive neurostimulation, though these latter therapies are supported by randomized-controlled trials, while MST is not. The reported complication rate of MST is higher than that of resection and neuromodulatory therapies. MST remains a viable option for the treatment of eloquent foci, provided a careful risk-benefit analysis is conducted.

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Impact of intraoperative 3-T MRI with diffusion tensor imaging on hemispherectomy

Journal of Neurosurgery Pediatrics ◽

10.3171/2016.4.peds15568 ◽

2017 ◽

Vol 19 (1) ◽

pp. 63-69 ◽

Cited By ~ 5

Author(s):

Gun-Ha Kim ◽

Joo Hee Seo ◽

Seema Schroff ◽

Po-Ching Chen ◽

Ki Hyeong Lee ◽

...

Keyword(s):

Diffusion Tensor Imaging ◽

Diffusion Tensor ◽

Outcome Data ◽

Seizure Outcome ◽

Seizure Freedom ◽

Cross Sectional ◽

Additional Surgery ◽

Class 1 ◽

Patients With Epilepsy

OBJECTIVE Hemispherectomy can produce remarkable seizure control of medically intractable hemispheric epilepsy in children, but some patients continue to have seizures after surgery. A frequent cause of treatment failure is incomplete surgical disconnection of the abnormal hemisphere. This study explores whether intraoperative 3-T MRI with diffusion tensor imaging (DTI) during hemispherectomy can identify areas of incomplete disconnection and allow complete disconnection during a single surgery. METHODS The charts of 32 patients with epilepsy who underwent hemispherectomy between January 2012 and July 2014 at the Florida Hospital for Children were reviewed. Patients were grouped as having had curative or palliative hemispherectomy. To assess the completeness of disconnection when the surgeon considered the operation completed, intraoperative 3-T MRI-DTI was performed. If incomplete disconnection was identified, additional surgery was performed until MRI-DTI sequences confirmed satisfactory disconnection. Seizure outcome data were collected via medical records at last follow-up. RESULTS Of 32 patients who underwent hemispherectomy, 23 had curative hemispherectomy and 9 had palliative hemispherectomy. In 11 of 32 surgeries, the first intraoperative MRI-DTI sequences suggested incomplete disconnection and additional surgery followed by repeat MRI-DTI was performed. Complete disconnection was accomplished in 30 of 32 patients (93.8%). Two of 32 disconnections (6.3%) were incomplete on postoperative imaging. Cross-sectional results showed that 21 of 23 patients (91.3%) who had curative hemispherectomy remained free of seizures (International League Against Epilepsy Class 1) at a median follow-up of 1.7 years (range 0.4–2.9 years). The longitudinal seizure freedom after curative hemispherectomy was 95.2% (SE 0.05) at 6 months, 90.5% (SE 0.06) at 1 year, and 90.5% (SE 0.05) at 2 years. CONCLUSIONS Intraoperative 3-T MRI-DTI sequences can identify incomplete disconnection during hemispherectomy and allow higher rates of complete disconnection in a single surgery. Higher rates of complete disconnection seem to achieve better seizure-free outcome following modified functional hemispherectomy.

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Seizure outcome in temporal glioblastoma surgery: lobectomy as a supratotal resection regime outclasses conventional gross-total resection

Journal of Neuro-Oncology ◽

10.1007/s11060-021-03705-x ◽

2021 ◽

Author(s):

Valeri Borger ◽

Motaz Hamed ◽

Inja Ilic ◽

Anna-Laura Potthoff ◽

Attila Racz ◽

...

Keyword(s):

Tumor Resection ◽

Temporal Lobectomy ◽

Secondary Outcome ◽

Seizure Outcome ◽

Seizure Freedom ◽

Secondary Outcome Measure ◽

Total Resection ◽

Class 1 ◽

Postoperative Seizure ◽

The Impact

Abstract Introduction The postoperative seizure freedom represents an important secondary outcome measure in glioblastoma surgery. Recently, supra-total glioblastoma resection in terms of anterior temporal lobectomy (ATL) has gained growing attention with regard to superior long-term disease control for temporal-located glioblastoma compared to conventional gross-total resections (GTR). However, the impact of ATL on seizure outcome in these patients is unknown. We therefore analyzed ATL and GTR as differing extents of resection in regard of postoperative seizure control in patients with temporal glioblastoma and preoperative symptomatic seizures. Methods Between 2012 and 2018, 33 patients with preoperative seizures underwent GTR or ATL for temporal glioblastoma at the authors’ institution. Seizure outcome was assessed postoperatively and 6 months after tumor resection according to the International League Against Epilepsy (ILAE) classification and stratified into favorable (ILAE class 1) versus unfavorable (ILAE class 2–6). Results Overall, 23 out of 33 patients (70%) with preoperative seizures achieved favorable seizure outcome following resection of temporal located glioblastoma. For the ATL group, postoperative seizure freedom was present in 13 out of 13 patients (100%). In comparison, respective rates for the GTR group were 10 out of 20 patients (50%) (p = 0.002; OR 27; 95% CI 1.4–515.9). Conclusions ATL in terms of a supra-total resection strategy was associated with superior favorable seizure outcome following temporal glioblastoma resection compared to GTR. Regarding above mentioned survival benefit following ATL compared to GTR, ATL as an aggressive supra-total resection regime might constitute the surgical modality of choice for temporal-located glioblastoma.

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The influence of lesion volume, perilesion resection volume, and completeness of resection on seizure outcome after resective epilepsy surgery for cortical dysplasia in children

Journal of Neurosurgery Pediatrics ◽

10.3171/2014.10.peds14282 ◽

2015 ◽

Vol 15 (6) ◽

pp. 644-650 ◽

Cited By ~ 30

Author(s):

Chima O. Oluigbo ◽

Jichuan Wang ◽

Matthew T. Whitehead ◽

Suresh Magge ◽

John S. Myseros ◽

...

Keyword(s):

Epilepsy Surgery ◽

Seizure Control ◽

Brain Mri ◽

Age At Onset ◽

Cortical Dysplasia ◽

Complete Resection ◽

Seizure Outcome ◽

Seizure Freedom ◽

Lesion Volume ◽

Resection Volume

OBJECT Focal cortical dysplasia (FCD) is one of the most common causes of intractable epilepsy leading to surgery in children. The predictors of seizure freedom after surgical management for FCD are still unclear. The objective of this study was to perform a volumetric analysis of factors shown on the preresection and postresection brain MRI scans of patients who had undergone resective epilepsy surgery for cortical dysplasia and to determine the influence of these factors on seizure outcome. METHODS The authors reviewed the medical records and brain images of 43 consecutive patients with focal MRI-documented abnormalities and a pathological diagnosis of FCD who had undergone surgical treatment for refractory epilepsy. Preoperative lesion volume and postoperative resection volume were calculated by manual segmentation using OsiriX PRO software. RESULTS Forty-three patients underwent first-time surgery for resection of an FCD. The age range of these patients at the time of surgery ranged from 2 months to 21.8 years (mean age 7.3 years). The median duration of follow-up was 20 months. The mean age at onset was 31.6 months (range 1 day to 168 months). Complete resection of the area of an FCD, as adjudged from the postoperative brain MR images, was significantly associated with seizure control (p = 0.0005). The odds of having good seizure control among those who underwent complete resection were about 6 times higher than those among the patients who did not undergo complete resection. Seizure control was not significantly associated with lesion volume (p = 0.46) or perilesion resection volume (p = 0.86). CONCLUSIONS The completeness of FCD resection in children is a significant predictor of seizure freedom. Neither lesion volume nor the further resection of perilesional tissue is predictive of seizure freedom.

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Association Between Anatomical Location of Surgically Induced Lesions and Postoperative Seizure Outcome in Temporal Lobe Epilepsy

Neurology ◽

10.1212/wnl.0000000000013033 ◽

2021 ◽

pp. 10.1212/WNL.0000000000013033

Author(s):

Ezequiel Gleichgerrcht ◽

Daniel L. Drane ◽

Simon Sean Keller ◽

Kathryn A. Davis ◽

Robert Gross ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Anterior Commissure ◽

Piriform Cortex ◽

Seizure Outcome ◽

Seizure Freedom ◽

Anatomical Location ◽

Surgical Interventions ◽

Postoperative Seizure ◽

Promising Source

Objective:To determine the association between surgical lesions of distinct grey and white structures and connections with favorable post-operative seizure outcomes.Methods:Patients with drug-resistant temporal lobe epilepsy (TLE) from three epilepsy centers were included. We employed a voxel-based and connectome-based mapping approach to determine the association between favorable outcomes and surgery-induced temporal lesions. Analyses were conducted controlling for multiple confounders, including total surgical resection/ablation volume, hippocampal volumes, side of surgery, and site where the patient was treated.Results:The cohort included 113 patients with TLE [54 women; 86 right-handed; 16.5 (SD = 11.9) age at seizure onset, 54.9% left] who were 61.1% free of disabling seizures (Engel class 1) at follow-up. Postoperative seizure freedom in TLE was associated with 1) surgical lesions that targeted the hippocampus as well as the amygdala-piriform cortex complex and entorhinal cortices; 2) disconnection of temporal, frontal, and limbic regions through loss of white matter tracts within the uncinate fasciculus, anterior commissure, and fornix; and 3) functional disconnection of the frontal (superior and middle frontal gyri, orbitofrontal region) and temporal (superior and middle pole) lobes.Conclusions:Better postoperative seizure freedom are associated with surgical lesions of specific structures and connections throughout the temporal lobes. These findings shed light on the key components of epileptogenic networks in TLE and constitute a promising source of new evidence for future improvements in surgical interventions.Classification of Evidence:This study provides Class II evidence that for patients with temporal lobe epilepsy, postoperative seizure freedom is associated with surgical lesions of specific temporal lobe structures and connections.

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Tumor-Associated Epilepsy in Patients With Brain Metastases: Necrosis-to-Tumor Ratio Forecasts Postoperative Seizure Freedom

10.21203/rs.3.rs-241560/v1 ◽

2021 ◽

Author(s):

Majd Bahna ◽

Muriel Heimann ◽

Christian Bode ◽

Valeri Borger ◽

Lars Eichhorn ◽

...

Keyword(s):

Risk Factors ◽

Brain Metastases ◽

Volume Ratio ◽

Seizure Outcome ◽

Seizure Freedom ◽

Treatment Regimes ◽

Related Quality ◽

Health Related ◽

Neurosurgical Treatment ◽

Postoperative Seizure

Abstract Surgical resection is highly effective in the treatment of tumor-related epilepsy (TRE) in patients with brain metastases (BM). Nevertheless, some patients suffer from postoperative persistent epilepsy which negatively impacts health-related quality of life. Therefore, early identification of patients with potentially unfavorable seizure outcome after BM resection is important. Patients with TRE that had undergone surgery for BM at the authors’ institution between 2013 and 2018 and were analyzed with regard to preoperatively identifiable risk factors for unfavorable seizure outcome. Tumor tissue and tumor necrosis ratios were assessed volumetrically. According to the classification of the International League Against Epilepsy (ILAE), seizure outcome was categorized as favorable (ILAE 1) and unfavorable (ILAE 2 - 6) after 3 months in order to avoid potential interference with adjuvant cancer treatment.Among all 38 patients undergoing neurosurgical treatment for BM with concomitant TRE, 34 patients achieved a favorable seizure outcome (90%). Unfavorable seizure outcome was significantly associated with larger tumor volumes (p=0.012), a midline shift > 7 mm (p=0.025), and a necrosis/tumor volume ratio > 0.2 (p=0.047).The present study identifies preoperatively collectable risk factors for unfavorable seizure outcome in patients with BM and TRE. This might enable to preselect for highly vulnerable patients with postoperative persistent epilepsy who might benefit from accompanying neuro-oncological expertise during further systemical treatment regimes.

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A-78 Interdisciplinary Consultation in a Case of Herpes Simplex Encephalitis with Unique Neuropsychiatric Symptoms

Archives of Clinical Neuropsychology ◽

10.1093/arclin/acab062.96 ◽

2021 ◽

Vol 36 (6) ◽

pp. 1121-1122

Author(s):

Danielle Kaplan ◽

John B O'Hara ◽

Carolina Posada ◽

Kristin E Slyne

Keyword(s):

Herpes Simplex ◽

Herpes Simplex Encephalitis ◽

Neuropsychiatric Symptoms ◽

Executive Dysfunction ◽

Brain Inflammation ◽

Neurological Deficits ◽

Cognitive Changes ◽

Fluid Analysis ◽

Intravenous Acyclovir ◽

Neuropsychological Evaluations

Abstract Objective Herpes simplex encephalitis (HSE) is a rare neurological condition (~2–4 per million) marked by brain inflammation caused by herpes simplex virus (HSV). HSE is associated with both cognitive and neuropsychiatric symptoms, particularly memory and executive dysfunction. We present the case of a 63-year-old, right-handed, St. Lucian female who completed serial neuropsychological evaluations (NPE). Method The patient presented with a six-day history (per collateral) of fever, confusion, and nausea. The patient denied cognitive changes. Magnetic Resonance Imaging (MRI) revealed leptomeningeal enhancement in the right sylvian fissure, multiple right temporal sulci, and inferior right frontal lobe (Figure 1). There was no indication of seizures. Cerebrospinal fluid analysis was positive for HSV-1. A two-week course of intravenous acyclovir was initiated on hospital day three. Results (Table 1). Initial NPE results (day five) revealed global cognitive impairment with sparing of auditory attention; exam was limited secondary to significant fatigue. Following completion of antivirals, subsequent NPE (day 17) revealed similar findings, despite improved alertness; left neglect (Figure 2) and significant anosagnosia (i.e., lack of disease awareness) and anosodiaphoria (i.e., indifference reaction to neurological deficits) were noted. Two-month outpatient follow-up NPE revealed marginal improvement in aspects of language and learning, but continued memory impairment, dense anosagnosia, and anosodiaphoria. Conclusion In this case, the patient presented with salient neuropsychiatric sequelae of HSE that have not been commonly associated with this condition in the extant literature. Her denial of cognitive symptoms may have initially confounded the differential diagnosis, emphasizing the importance of multi-specialty collaboration. Limitations of available normative data also complicated examination.

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Application of the APE2-CHN and RITE2-CHN scores for autoimmune epilepsy in Chinese patients: a retrospective study

10.21203/rs.3.rs-18039/v1 ◽

2020 ◽

Author(s):

Wei-ping Liu ◽

Mian Wang ◽

Chen Zhang ◽

Charlie Weige Zhao ◽

Bo Xiao ◽

...

Keyword(s):

Retrospective Study ◽

Sensitivity And Specificity ◽

Chinese Patients ◽

Unknown Etiology ◽

Thyroid Peroxidase ◽

Seizure Outcome ◽

Receptor Antibody ◽

Autoimmune Epilepsy ◽

Patients With Epilepsy ◽

New Onset

Abstract Background : Autoimmune epilepsy is recognized as a distinct entity of epilepsy with underestimated incidence. Our previous study reported that prompt diagnosis and early-initiated immunotherapy led to better outcome. We proposed to assess the feasibility and reasonability of the Antibody Prevalence in Chinese Patients with Epilepsy and Encephalopathy (APE 2 -CHN) and Response to Immunotherapy in Chinese Patients with Epilepsy and Encephalopathy (RITE 2 -CHN) scores in predicting Chinese patients with autoimmune epilepsy. Methods : We conducted a retrospective study of consecutive patients from Xiangya Hospital, Central South University (01/01/2017-02/28/2019) whose serum and/or cerebrospinal fluid (CSF) samples were examined for autoimmune encephalitis antibodies. Of these, patients with new-onset epilepsy or established epilepsy of unknown etiology were selected in our study. An APE 2 -CHN score was assigned to each patient and a RITE 2 -CHN score was calculated for each patient who received immunotherapy. Results : 191 patients meeting the diagnostic criteria for epilepsy were enrolled in our study. 36 were subsequently identified with specific etiologies. The rest of the 155 patients had an unknown etiology. Central nervous system-specific antibodies were detected in 76 (49.0%) of them, after excluding solely thyroid peroxidase antibody or glutamic acid decarboxylase antibody. N-methyl-D-aspartate receptor antibody (48.7%, 37/76) was the most common antibody specificity, followed by γ-aminobutyric acid type B receptor antibody (14.5%, 11/76). Certain clinical features such as new-onset epilepsy, autonomic dysfunction, viral prodrome, facio-brachial dystonic seizures/oral dyskinesia, inflammatory CSF profile, and mesial temporal magnetic resonance imaging abnormalities correlated with positive antibody results. Sensitivity and specificity of an APE 2 -CHN score ≥ 5 to predict the presence of specific neural auto-antibodies in our study were 85.5% and 58.9%, respectively. In the subset of patients who received immunotherapy (n = 112), sensitivity and specificity of a RITE 2 -CHN score ≥ 8 to predict favorable seizure outcome were 98.6% and 63.2% respectively. Conclusion : The APE 2 -CHN and RITE 2 -CHN scores were preferable tools in predicting positive serologic findings and prognosis of autoimmune epilepsy in Chinese patients with epilepsy.

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Lesion Network Localization of Seizure Freedom following MR-guided Laser Interstitial Thermal Ablation

Scientific Reports ◽

10.1038/s41598-019-55015-y ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Karim Mithani ◽

Alexandre Boutet ◽

Jurgen Germann ◽

Gavin J. B. Elias ◽

Alexander G. Weil ◽

...

Keyword(s):

Resting State ◽

Target Selection ◽

Brain Regions ◽

Seizure Outcome ◽

Seizure Freedom ◽

Anatomical Location ◽

Treatment Resistant ◽

Resting State Functional Connectivity ◽

Network Localization ◽

Subcortical Regions

AbstractTreatment-resistant epilepsy is a common and debilitating neurological condition, for which neurosurgical cure is possible. Despite undergoing nearly identical ablation procedures however, individuals with treatment-resistant epilepsy frequently exhibit heterogeneous outcomes. We hypothesized that treatment response may be related to the brain regions to which MR-guided laser ablation volumes are functionally connected. To test this, we mapped the resting-state functional connectivity of surgical ablations that either resulted in seizure freedom (N = 11) or did not result in seizure freedom (N = 16) in over 1,000 normative connectomes. There was no difference seizure outcome with respect to the anatomical location of the ablations, and very little overlap between ablation areas was identified using the Dice Index. Ablations that did not result in seizure-freedom were preferentially connected to a number of cortical and subcortical regions, as well as multiple canonical resting-state networks. In contrast, ablations that led to seizure-freedom were more functionally connected to prefrontal cortices. Here, we demonstrate that underlying normative neural circuitry may in part explain heterogenous outcomes following ablation procedures in different brain regions. These findings may ultimately inform target selection for ablative epilepsy surgery based on normative intrinsic connectivity of the targeted volume.

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