Temporal Resection Research Articles

Temporal Lobe Surgery in Pediatric Patients: From Temporal Lobe Epilepsy to Temporal Plus Epilepsy

Purpose: Temporal lobe resection can be categorized as either temporal lobe epilepsy (TLE), which involves cortical resection confined to the temporal lobe, or temporal plus epilepsy (TPE), which entails temporal resection along with involvement of additional extratemporal regions. We compared these forms within a pediatric population.Methods: We identified 136 patients who underwent temporal resection over a 17-year period and investigated the differences in the clinical profiles and seizure outcomes between TLE and TPE.Results: Of the total sample, 110 patients (80.9%) presented with TLE and 26 (19.1%) with TPE. Significant differences were observed between the groups in age at seizure onset (TLE: 6.3 years, TPE: 0.9 years; P=0.001), age at epilepsy surgery (TLE: 14.2 years, TPE: 9.2 years; P=0.002), the proportion of patients with a history of infantile epileptic spasm syndrome (IESS) (TLE: 6 [5.5%], TPE: 8 [30.3%]; P<0.001), electroclinical presentation with IESS or Lennox-Gastaut syndrome (LGS) (TLE: 11 [10.0%], TPE: 13 [50.0%]; P<0.001), the presence of focal temporal hypometabolism on positron emission tomography (TLE: 74 [68.5%], TPE: 11 [44.0%], P=0.021), and the use of intracranial electroencephalogram monitoring (TLE: 58 [52.7%], TPE: 21 [80.8%]; P=0.009). Furthermore, multivariate analysis identified the epileptic presentation of IESS or LGS as a significant predictor of TPE (P=0.049). The rates of seizure outcomes of International League Against Epilepsy class 1–3 at 1 year of follow-up were 83.8% for the entire cohort, 89.1% for TLE, and 61.5% for TPE (P=0.002).Conclusion: TPE appears to represent a substantial subset of pediatric temporal resections. The variation in seizure outcomes between groups underscores the importance of predicting TPE in advance, with implications for effective treatment planning.

Temporal PLGG and epilepsy.

Temporal lobe epilepsy in children is often secondary to various low-grade glial and glioneural tumors and rarely secondary to mesial temporal sclerosis. Despite the benign nature, tumor-associated TLE in children often becomes refractory over time. Abundant literature has shown the significant advantage of tumor resection compared to conservative treatment, in achieving seizure control, as well as the rates of antiseizure medication reduction. Despite these advantages, several considerations are to be related to when considering surgery. These include the impact of surgery on linguistic and neurocognitive development, especially at the younger age; the extent of resection and the role of ECoG; and the need for mesial temporal resection. Over recent years, traditional resection has been complemented with newer treatment options such as laser ablation and biological treatment, and these should be taken into account depending on the exact location and the ability to perform extensive resection in eloquent regions. In this overview manuscript, we discuss the various considerations treating tumor-associated pediatric temporal epilepsy.

Surgical cavity dilatation after resection of IDH-mutated astrocytoma of the mesial temporal lobe: illustrative cases.

Space-occupying tumor bed cysts may exceptionally happen after the resection of diffuse low-grade glioma. Their mechanism and management remain debated. The authors report two cases of tumor bed cysts occurring after the resection of a left temporal diffuse low-grade glioma with two different evolutions. The first patient showed a spontaneous decrease in the cyst volume and did not report any symptoms. In contrast, the second patient showed a progressive increase in the cyst volume and reported headaches and difficulties in finding words. Endoscopic cyst fenestration was performed and led to symptom relief and normalization of the surgical cavity. A tumor bed cyst is a rare complication of temporal low-grade glioma resection. Its formation is due to entrapment of the choroid plexus in the temporal horn widely opened into the surgical cavity. Endoscopic cyst fenestration should be offered only in symptomatic cases. https://thejns.org/doi/10.3171/CASE23674.

Chronologic Changes in Transcranial Motor Evoked Potential During Anterior Temporal Lobectomy in Patients with Temporal Lobe Epilepsy: A Single-Center Cross-Sectional Analytic Study

Despite the benefits of anterior temporal lobectomy with amygdalohippocampectomy in patients with temporal lobe epilepsy (TLE), approximately up to 5% may have hemiparesis as its postoperative complication. This paper aims to describe which step/s of the anterior temporal lobectomy with amygdalohippocampectomy have the highest probability of having the greatest decrease in motor evoked potential (MEP) amplitude. This study used a cross-sectional design of obtaining data from TLE patients who underwent anterior temporal lobectomy with amygdalohippocampectomy with transcranial MEP monitoring. Each of the following steps were evaluated for reduction in MEP amplitude: 1) dural opening, 2) opening the inferior horn, 2) vertical temporal lobe resection 3) subpial dissection, 4) temporal lobe stem resection, 5) lateral temporal lobe resection, 6) hippocampal resection, 7) amygdala resection, 8) uncus resection, and 9) dural closure. Nineteen patients were included in the study. Based on the Friedman Test, 1 or more steps had significantly different average MEP amplitude reductions (Friedman= 50.7, P= 0.0001). When compared with baseline (100%, cutoff P= 0.005), hippocampal resection (z= -3.81, P < 0.0001), T1 subpial dissection (z= -3.2, P= 0.0010), uncus resection (z= -3.48, P= 0.0002), temporal stem resection (z= -3.26, P= 0.001), lateral temporal lobe resection (z= -3.13, P= 0.002), and amygdalectomy (-z= -3.37, P= 0.0005) were significantly lower. Of these, hippocampal resection, uncus resection, and amygdalectomy were deemed highly significant. MEP amplitude tends to decrease during amygdala, hippocampal, and uncal resection because of surgical manipulation of anterior choroidal arteries, which can potentially cause hemiparesis. Careful attention should be paid to changes in MEP during these steps.

P.122 Left temporal aneurysm resection: surgical approach in Pial-Pial collateral formation from the posterior temporal artery secondary to left internal artery occlusion

Background: The formation of pial-pial collateral network aneurysms due to carotid occlusion is a rare neurological phenomenon. This case details a 69-year-old male who developed a pial-pial collateral network aneurysm secondary to left internal carotid artery occlusion, leading to intracranial hemorrhage. Methods: The patient presented with altered consciousness due to left temporal intracerebral hemorrhage, subdural hematoma, and intraventricular hemorrhage. Cerebral angiography revealed an occluded left internal carotid artery, with superficial temporal artery (STA) and superior orbital artery anastomosis, and extensive pial-pial collaterals from the posterior temporal artery. A 4 mm aneurysm arising from this collateral network was identified. Surgical intervention involved a left temporal craniectomy and excision of the aneurysm, prioritizing the preservation of the STA. N.B., Informed patient consent was obtained in this study. Results: Successful aneurysm removal and preservation of collateral pathways were confirmed by postoperative imaging. The patient exhibited rapid neurological improvement; by postoperative day (POD) one, the patient showed limited response to stimuli. He was extubated by POD4 and discharged on POD27, where he conversed well, was independently ambulatory, and needed minimal to no assistance in activities of daily living. Conclusions: This case highlights the need for careful preoperative planning and intraoperative precision, especially in preserving vital collateral vascular pathways.

Outcomes of stereoelectroencephalography following failed epilepsy surgery in children.

Stereoelectroencephalography (SEEG) is valuable for delineating the seizure onset zone (SOZ) in pharmacoresistant epilepsy when non-invasive presurgical techniques are inconclusive. Secondary epilepsy surgery after initial failure is challenging and there is limited research on SEEG following failed epilepsy surgery in children. The objective of this manuscript is to present the outcomes of children who underwent SEEG after failed epilepsy surgery. In this single-institution retrospective study, demographics, previous surgery data, SEEG characteristics, management, and follow-up were analyzed for pediatric patients who underwent SEEG after unsuccessful epilepsy surgery between August 2016 and February 2023. Fifty three patients underwent SEEG investigation during this period. Of this, 13 patients were identified who had unsuccessful initial epilepsy surgery (24%). Of these 13 patients, six patients (46%) experienced unsuccessful resective epilepsy surgery that targeted the temporal lobe, six patients (46%) underwent surgery involving the frontal lobe, and one patient (8%) had laser interstitial thermal therapy (LITT) of the right insula. SEEG in two thirds of patients (4/6) with initial failed temporal resections revealed expanded SOZ to include the insula. All 13 patients (100%) had a subsequent surgery after SEEG which was either LITT (54%) or surgical resection (46%). After the subsequent surgery, a favorable outcome (Engel class I/II) was achieved by eight patients (62%), while five patients experienced an unfavorable outcome (Engel class III/IV, 38%). Of the six patients with secondary surgical resection, four patients (67%) had favorable outcomes, while of the seven patients with LITT, two patients (29%) had favorable outcomes (Engel I/II). Average follow-up after the subsequent surgery was 37 months ±23 months. SEEG following initial failed resective epilepsy surgery may help guide next steps at identifying residual epileptogenic cortex and is associated with favorable seizure control outcomes.

476 Middle Cranial Fossa Encephaloceles With Temporal Lobe Epilepsy: An Underdiagnosed Entity

INTRODUCTION: Temporal lobe epilepsy with encephalocele (TLEE) is a lesional epilepsy increasingly recognized as underdiagnosed. Here we report our experience with TLEE-associated epilepsy managed with both traditional ATL with AH compared to a targeted lesionectomy of the encephalocele. METHODS: We used a prospectively maintained database of surgical epilepsy patients to identify all patients with TLEE-associated epilepsy managed over a 13-year interval using ATL with AH, ATL only, or a targeted encephalocele-only lesionectomy. Details regarding epilepsy, neuropsychology, management, complications, and outcomes at the last follow-up were compiled. RESULTS: 793 surgical epilepsy patients were evaluated, with 56 (7.1%) demonstrating TLEE. The average age of epilepsy onset was 31.7 years (range 2-57); the age at the time of surgery was 38.3 years (range 15-69). Twenty-one patients (37.5%) were managed with ATL with AH, 20 (35.7%) with temporal pole resection without AH, and 15 (26.7%) with targeted lesionectomy/LITT of the temporal encephalocele. Forty-seven patients (84%) had good surgical epilepsy outcomes with no significant difference in modality. Targeted lesionectomy demonstrated significantly greater language preservation (p = 0.046) and verbal memory (p = 0.038) when compared to more extensive surgical resections. CONCLUSIONS: TLEE is an overlooked and underreported etiology of epilepsy. In select cases, good surgical epilepsy outcomes can be achieved with targeted lesionectomy of the encephalocele when the epilepsy network is not widespread.

Virtual Surgical Planning and Customized CAD/CAM Cranial Implants: Preoperative and Intraoperative Strategies for Temporal Intraosseous Meningioma Resection.

Primary intraosseous meningioma (PIM) is a rare subtype of extradural meningiomas, with the indication for surgical resection in most cases. With an increasing demand for efficient workflows with optimal functional and cosmetical results, techniques for bone reconstruction after resection are developing rapidly. The authors present 2 cases with one-stage cranioplasty after resection of PIM, using 3D technology for preplanned patient-specific implants. In the first case, a premanufactured patient-specific PEEK implant was used for reconstruction; in the second case, a 3-dimensional (3D)-based premanufactured silicon mold was used to produce a customized PMMA implant intraoperatively. Both techniques enabled the surgeons to achieve optimal intraoperative fit of the implant after craniectomy, leading to satisfying functional and cosmetic results. The use of 3D technology, such as Computer-Aided Design and Computer-Aided Manufacturing (CAD/CAM) for the production of patient-specific implants can optimize 1-stage cranioplasty after PIM resection.

Pure amnestic seizure: A clinico-intracranial EEG study.

Enduring anterograde amnesia is caused by lesions in bilateral mesial temporal lobes. However, whether transient dysfunction of bilateral mesial temporal regions induces reversible amnesia has not been proven. We investigated this association in patients with epilepsy and analyzed the electroclinical correlation during pure amnestic seizures (PAS). PAS are defined as seizures with anterograde amnesia as the only ictal manifestation, accompanied by preserved responsiveness and other cognitive functions. We retrospectively searched our intracranial EEG database to find PAS. Pure ictal amnesia was confirmed by immediate and comprehensive ictal examinations. Among 401 patients who underwent intracranial EEG recording, three patients with temporal lobe epilepsy (TLE) manifesting PAS were identified. The patients talked and behaved normally during seizure but did not remember the episodes afterwards. Ictal discharges were confined to bilateral mesial temporal regions, with no or mild involvement of surrounding structures. Spread of low-voltage fast activities to bilateral mesial temporal regions corresponded to onset of ictal anterograde amnesia. Two patients underwent unilateral mesial temporal resection and became seizure-free with improvement in cognitive functions. PAS is a rare ictal semiology in TLE. Bilateral mesial temporal regions that play a critical role in memory encoding are presumably the symptomatogenic zones for PAS.

Impairment of unconscious emotional processing after unilateral medial temporal structure resection

The role of the amygdala in unconscious emotional processing remains a topic of debate. Past lesion studies have indicated that amygdala damage leads to impaired electrodermal activity in response to subliminally presented emotional stimuli. However, electrodermal activity can reflect both emotional and nonemotional processes. To provide behavioral evidence highlighting the critical role of the amygdala in unconscious emotional processing, we examined patients (n = 16) who had undergone unilateral resection of medial temporal lobe structures, including the amygdala. We utilized the subliminal affective priming paradigm in conjunction with unilateral visual presentation. Fearful or happy dynamic facial expressions were presented in unilateral visual fields for 30 ms, serving as negative or positive primes. Subsequently, neutral target faces were displayed, and participants were tasked with rating the valence of these targets. Positive primes, compared to negative ones, enhanced valence ratings of the target to a greater extent when they stimulated the intact hemisphere (i.e., were presented in the contralateral visual field of the intact hemisphere) than when they stimulated the resected hemisphere (i.e., were presented in the contralateral visual field of the resected hemisphere). These results suggest that the amygdala is causally involved in unconscious emotional processing.

Indirect structural changes and reduced controllability after temporal lobe epilepsy resection.

To understand the potential behavioral and cognitive effects of mesial temporal resection for temporal lobe epilepsy (TLE) a method is required to characterize network-wide functional alterations caused by a discrete structural disconnection. The objective of this study was to investigate network-wide alterations in brain dynamics of patients with TLE before and after surgical resection of the seizure focus using average regional controllability (ARC), a measure of the ability of a node to influence network dynamics. Diffusion-weighted imaging (DWI) data were acquired in 27 patients with drug-resistant unilateral mesial TLE who underwent selective amygdalohippocampectomy. Imaging data were acquired before and after surgery and a presurgical and postsurgical structural connectome was generated from whole-brain tractography. Edge-wise strength, node strength, and node ARC were compared before and after surgery. Direct and indirect edge-wise strength changes were identified using patient-specific simulated resections. Direct edges were defined as primary edges disconnected by the resection zone itself. Indirect edges were secondary measured edge strength changes. Changes in node strength and ARC were then related to both direct and indirect edge changes. We found nodes with significant postsurgical changes in both node strength and ARC surrounding the resection zone (paired t tests, p < .05, Bonferroni corrected). ARC identified additional postsurgical changes in nodes outside of the resection zone within the ipsilateral occipital lobe, which were associated with indirect edge-wise strength changes of the postsurgical network (Fisher's exact test, p < .001). These indirect edge-wise changes were facilitated through the "hub" nodes including the thalamus, putamen, insula, and precuneus. Discrete network disconnection from TLE resection results in widespread structural and functional changes not predicted by disconnection alone. These can be well characterized by dynamic controllability measures such as ARC and may be useful for investigating changes in brain function that may contribute to seizure recurrence and behavioral or cognitive changes after surgery.

Who are the Better Candidates for Epilepsy Surgery?

The resective epilepsy surgery can be the effective procedure to get seizure-free outcome in these drug resistant epilepsy (DRE) patients. Class I evidence firmly establishes the superiority of epilepsy surgery over medical treatments in both seizure control and quality of life for DRE patients. For the effective identification of optimal surgical candidates, it's essential to understand the prognostic factors of epilepsy surgery based on the surgical methods employed. Established positive prognostic indicators for temporal resection include the presence of hippocampal sclerosis on magnetic resonance imaging (MRI), focal lesions on MRI, unilateral temporal spikes, concordant ictal electroencephalography (EEG), and a history of prolonged febrile convulsion. Potential negative predictors encompass preoperative secondary generalized tonic-clonic seizures, a normal MRI, postoperative EEG spikes, and age at the time of surgery. For neocortical epilepsy, the prognostic factors identified through multivariate analysis were the presence of a discrete lesion, localized hypometabolism on Fluorodeoxyglucose positron emission tomography (FDG-PET), and localized ictal EEG. A significant correlation was found between achieving a seizure-free outcome in no visible lesion on MRI (MR-negative) epilepsy patients and having concordance in two or more presurgical evaluations, specifically in interictal EEG, ictal EEG, FDG-PET, and ictal single-photon emission computed tomography. There was a marked improvement in the seizure-free outcome in MR-negative temporal lobe epilepsy (TLE) by the application of this strategy. The better surgical candidates for epilepsy surgery are the followings: patients displaying a discrete lesion on MRI with concordant video-EEG monitoring (VEM) results, patients diagnosed with unilateral hippocampal sclerosis who have concordant VEM results, patients with unilateral hippocampal sclerosis but discordant VEM results, patients with focal cortical dysplasia and concordant VEM results, and patients diagnosed with MR-negative TLE who exhibit two or more consistent results from presurgical evaluations.

Investigating the effect of hippocampal sclerosis on parietal memory network.

We aimed to investigate differences in episodic memory networks between patients with temporal lobe epilepsy (TLE) due to hippocampal sclerosis and healthy controls, especially with regards to the parietal memory network (PMN), as well as their relation to neuropsychological memory performance after mesial temporal resection. 28 healthy subjects as well as 21 patients with TLE (12 left, 9 right) were investigated using a spatial memory fMRI paradigm, which has been shown to activate the PMN. Regions of interest (ROI) were defined based on the results of the second-level analyses and activations within the predefined ROIs were compared across groups and correlated with postoperative verbal and nonverbal memory scores. Healthy subjects showed activations within regions belonging to the dorsal visual stream and the PMN as well as the bilateral parahippocampal place area, the bilateral frontal eye field, and the bilateral middle frontal gyrus. Comparison between groups revealed that TLE patients activated significantly less in the left middle occipital gyrus and the right precuneus. The activation pattern in left TLE patients showed further reductions, mainly in areas belonging to the dorsal visual stream and the PMN within the left hemisphere. Activations within the left superior parietal lobulus, bilateral inferior parietal lobulus, bilateral middle temporal gyrus, left precuneus, left frontal eye field, and left middle frontal gyrus correlated significantly with postoperative verbal memory scores, and activations within the left superior parietal lobulus, left inferior parietal lobulus, left middle temporal gyrus, and left precuneus correlated significantly with higher performance in postoperative nonverbal memory scores. The PMN is involved in episodic memory encoding. Higher activations in areas belonging to the PMN and the dorsal visual stream, especially within the left hemisphere, before amygdalohippocampectomy may result in higher postoperative memory scores. This study aims to investigate the effects of epilepsy due to hippocampal sclerosis, i.e. scarring in the temporal lobe, on memory networks in the brain. We discovered that especially patients with left-sided hippocampal sclerosis show reduced brain activations in visual areas and memory networks within the left hemisphere of the brain during orientation in space. Importantly, higher activations within these areas may result in better memory after epilepsy surgery.

38 Language and memory outcome after frontal or temporal resection for epilepsy

Objective:The purpose of this investigation was to examine neuropsychological functioning after frontal (FL) or temporal lobectomy (ATL) in patients with localization related epilepsy. Few studies have compared cognitive changes following FL and ATL. Past research found improvement on measures of verbal and visual memory along with confrontation naming after FL (Busch et al., 2017). In contrast, a number of studies have reported verbal memory and naming decline in those undergoing left ATL. The current study examined post-operative cognitive changes in epilepsy patients who underwent either a left or right FL or ATL.Participants and Methods:Subjects include 430 patients (204 men, 225 women, 1 gender not specified), who underwent surgical resection; Right FL = 25, Left FL = 26, Right ATL = 211, Left ATL = 168. Patients had a mean FSIQ = 90, ages ranging from 18 to 71 (mean age = 37 years), right (n=359), left (n=50), or mixed (n=18) handedness, and education ranging from 3 to 22 years (mean = 12.9 years of education). Change from pre- to post FL and ATL was examined in the following domains: learning and memory [Long Term Storage for Selective Reminding Tests (SRT), Wechsler’s Memory Scale (WMS): Logical Memory Delayed Recall (LM) and Visual Reproduction Delayed Recall (VR)], and language [Boston Naming Test (BNT)].Results:A one-way ANOVA was used to examine changes in language and memory. Our findings revealed statistically significant differences between resection groups for LM, SRT, and BNT. There were significant declines (p&lt;.001) for left ATL when compared to right ATL for LM, SRT, and BNT. There were significant declines for left ATL, when compared to the gains in both left (p&lt;.001; p=.002) and right (p=.018; p=.008) FL for LM and BNT. Left ATL also had significant declines when compared to gains in SRT (p&lt;.001) for right FL. There were significant declines for left FL when compared to right ATL for SRT (p=.007). Lastly, there were significant gains for right FL when compared to left FL for SRT (p=.020).Conclusions:The pre- to post-surgical neuropsychological change in learning, memory, and language is understudied in frontal lobe epilepsy (FLE); although several investigators reported some learning and memory impairments in FLE at either pre- or post-surgical time points (Johnson-Markve et al., 2011; Incisa Della Rocchetta et al., 1993). The current study suggests that resections of the frontal lobes are associated with better outcomes for naming and verbal memory (LM) when compared to left ATLs. Interestingly, verbal list learning declined more in left than right FL and right ATL patients suggesting a possible language based executive functioning component to this memory measure. As expected, our study further supports that left ATLs are associated with material specific memory declines. This pattern was not seen for those undergoing a right ATL (i.e., nonverbal memory did not decline in patients with right ATL).

H - 24 The Role of Bilingual Neuropsychologists in Presurgical Epilepsy Evaluations: La Evaluación Comprensiva en Español.

As neuropsychologists continually work to establish clinical standards of practice for evaluation of linguistically and culturally diverse children with epilepsy (Berrios-Siervo et al., 2023), this case study supports efforts to document complex assessment procedures with an adolescent who recently immigrated from Mexico to the U.S. A 16-year-old, right-handed, primarily Spanish-speaking, Hispanic male with intractable epilepsy (complex partial seizures) was referred for a presurgical neuropsychological evaluation. Medication was initiated in Mexico at age 11years, but increased frequency and severity of seizures prompted immigration to the U.S. at age 14 for further treatment. EEG and brain MRI indicated left hemisphere involvement. Magnetoencephalography results indicated right-hemisphere dominance for receptive language. Functional MRI (fMRI) indicated left-hemisphere dominance. Subsequent Wada and bilateral language mapping results supported left-hemisphere dominance. Personal history was significant for anxiety and depressed mood. Bilingual neuropsychologists completed a presurgical evaluation, fMRI, stereo EEG language mapping, and Wada in Spanish. He was seizure-free 6months post selective left temporal resection. He recently completed his1-year post-op evaluation. Baseline testing indicated average neurocognitive functioning, with select relative weaknesses lacking strong evidence for lateralization/localization. Post-operative consultation/ evaluation at 6 and 12months, respectively, revealed the patient was doing well academically with perceived improvements in attention and memory and minimal language difficulties. Reported improvements in mood were attributed to family reunification and increased social engagement. In addition to pre/post-surgical assessment in Spanish, bilingual neuropsychologists are uniquely positioned to contribute to the establishment of culturally-informed, standardized approaches to essential aspects of the presurgical workup (e.g., language mapping, Wada).

Extent of piriform cortex resection in children with temporal lobe epilepsy.

A greater extent of resection of the temporal portion of the piriform cortex (PC) has been shown to be associated with higher likelihood of seizure freedom in adults undergoing anterior temporal lobe resection (ATLR) for drug-resistant temporal lobe epilepsy (TLE). There have been no such studies in children, therefore this study aimed to investigate this association in a pediatric cohort. A retrospective, neuroimaging cohort study of children with TLE who underwent ATLR between 2012 and 2021 was undertaken. The PC, hippocampal and amygdala volumes were measured on the preoperative and postoperative T1-weighted MRI. Using these volumes, the extent of resection per region was compared between the seizure-free and not seizure-free groups. In 50 children (median age 9.5 years) there was no significant difference between the extent of resection of the temporal PC in the seizure-free (median = 50%, n = 33/50) versus not seizure-free (median = 40%, n = 17/50) groups (p = 0.26). In a sub-group of 19 with ipsilateral hippocampal atrophy (quantitatively defined by ipsilateral-to-contralateral asymmetry), the median extent of temporal PC resection was greater in children who were seizure-free (53%) versus those not seizure-free (19%) (p = 0.009). This is the first study demonstrating that, in children with TLE and hippocampal atrophy, more extensive temporal PC resection is associated with a greater chance of seizure freedom-compatible with an adult series in which 85% of patients had hippocampal sclerosis. In a combined group of children with and without hippocampal atrophy, the extent of PC resection was not associated with seizure outcome, suggesting different epileptogenic networks within this cohort.

Epilepsy surgery in a neonate: Resection of Right Temporal Neocortical Focal Cortical Dysplasia in a Three-Week-Old Infant. (P10-9.003)

<h3>Objective:</h3> n/a <h3>Background:</h3> Epilepsy surgery offers opportunity for seizure remission in patients with focal epilepsy refractory to polytherapy. Traditionally, only small portion of patients with drug resistant epilepsy are referred for surgical consideration. The patients who are referred on average have had epilepsy for two decades or more, leading to seizure related complications. We present our case report of an infant with severe refractory epilepsy, who underwent right temporal neocortical resection for focal cortical dysplasia at day 21 of life <h3>Design/Methods:</h3> Baby born at 38 weeks, on day of life 3 had apneic events associated with movements of her mouth and eye deviation to left. On EEG monitoring showed focal motor seizures originating from right temporal region. MRI Head revealed area of cortical dysplasia in the right middle and inferior temporal gyrus. The seizures were initially controlled but had breakthrough seizures on polytherapy requiring readmission. Risk of ongoing seizures with potential risks of surgery at young age were reviewed by our multidisciplinary team. As resection of the lesion would be curative, parents agreed for the procedure. Patient had the surgery: right sided hippocampal sparing temporal neocortical resection on Day of life 21. Patient was monitored post procedure, there were no seizures, so patient was able to be weaned off phenobarbital and phenytoin. Patient had repeat EEG 3 weeks post procedure for facial twitching and they were not epileptic. In the past year, patient was able to be weaned to Topiramate monotherapy with no further seizures and normal development for age. <h3>Results:</h3> n/a <h3>Conclusions:</h3> We present this case to highlight the use of surgical resection in infants with refractory focal seizures, even within the first month of life. Our patient has had a seizure free first year of life, is now on monotherapy, and her development is normal. <b>Disclosure:</b> Dr. Gangishetti has nothing to disclose. Dr. Ilgarli has nothing to disclose. Mrs. Tadisetty has nothing to disclose. Dr. Mirza has nothing to disclose. Dr. Haghighat has nothing to disclose.

Outcomes of Surgical Resection and VNS in Patients with Medically Refractory Epilepsy and GAD65 Antibody Positivity (S40.004)

<h3>Objective:</h3> To determine effectiveness of vagus nerve stimulator (VNS) and surgical resection in patients with drug-resistant epilepsy associated with glutamic acid decarboxylase 65 (GAD65) antibodies. <h3>Background:</h3> Epilepsy associated with high-titer GAD65 antibodies is often refractory to immunotherapies and antiseizure medications (ASMs), underscoring the need for alternate treatment strategies. <h3>Design/Methods:</h3> We retrospectively identified Mayo Clinic Rochester patients (January 2003 – April 2022) with drug-resistant epilepsy and high serum GAD65-antibody titers (&gt;20 nnmol/L) who underwent surgical resection and/or VNS implantation. A “favorable” surgical outcome was defined as Engel I-II, and a responder to VNS was defined as a &gt;50% reduction in seizure frequency from baseline. <h3>Results:</h3> We identified 15 patients (13 females, 86.7%) who underwent surgical resection (n=7), VNS implantation (n=6), and both (n=2). Patients had failed a median of 5.5 anti-seizure medications. Twelve patients had GAD65 tested in the CSF, all were positive (median titer 3.8). Of the nine patients who underwent surgical intervention (all involving the temporal region), three (33.3%) had a favorable outcome, which was sustained for at least 3.5 years in one, 10 years in another, and the third was lost to follow-up after 1 year. Pathology was available in four patients, only one had evidence of inflammation. Of the 8 patients who underwent VNS implantation, 3 (37.5%) were initially considered a responder, but this was not sustained in two of the three. No clinical factors were statistically associated with favorable surgical or VNS outcomes. <h3>Conclusions:</h3> Temporal surgical resection and VNS are not highly effective in drug-resistant autoimmune-associated epilepsy related to high-titer GAD65 antibodies. Additional therapies are greatly needed for this challenging clinical scenario. <b>Disclosure:</b> Dr. Zhao-Fleming has nothing to disclose. Dr. Britton has received personal compensation in the range of $0-$499 for serving as a Online course with American Clinical Neurophysiology Society. The institution of Dr. Dubey has received personal compensation in the range of $500-$4,999 for serving as a Consultant for UCB. The institution of Dr. Dubey has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Astellas. The institution of Dr. Dubey has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Argenx. Dr. Dubey has received personal compensation in the range of $0-$499 for serving on a Speakers Bureau for AGRIMS. Dr. Dubey has received personal compensation in the range of $0-$499 for serving on a Speakers Bureau for Advances in Neurology . Dr. Dubey has received personal compensation in the range of $0-$499 for serving on a Speakers Bureau for Moffit Cancer Center . Dr. Dubey has received research support from Department of Defense . Dr. Dubey has received intellectual property interests from a discovery or technology relating to health care. Dr. Dubey has received intellectual property interests from a discovery or technology relating to health care. Dr. Dubey has received intellectual property interests from a discovery or technology relating to health care. The institution of Dr. Smith has received research support from CURE Epilepsy.

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.

You Take the Low Road: Differential Outcomes After Tangential and Transcortical Approaches to Medial Temporal Brain Arteriovenous Malformations

Microsurgical resection of medial temporal brain arteriovenous malformations (AVMs) is typically conducted through 2 approaches: the orbitozygomatic-tangential and subtemporal-transcortical. Relative indications and outcomes for these techniques have not been formally compared. The cerebrovascular database of a quaternary center was reviewed for patients with medial temporal AVMs treated between January 1, 1997, and July 31, 2021. Demographic characteristics, lesion characteristics, surgical approaches, and outcomes were retrospectively analyzed and compared. Postoperative outcome testing was performed using the Montreal Cognitive Assessment and Global Quality of Life Scale. Fifty-nine patients were assessed. Mean (standard deviation) age was 31 (18) years; 30 (51%) patients were male. Of the AVMs, 29 (49%) were left-sided and 30 (51%) were right-sided. The tangential approach was selected in 20 (34%) cases, whereas the transcortical technique was preferred in 39 (66%). Improved modified Rankin Scale status was significantly associated with the tangential resection technique both in the early postoperative period (P= 0.02) and at last follow-up (P= 0.01). Differences between the tangential and transcortical approaches were not significant with respect to new postoperative deficits (5/20 [25%] vs. 12/39 [31%], P= 0.87) or the presence of residual AVM on follow-up angiography (1/20 [6%] vs. 5/39 [14%], P= 0.65). The orbitozygomatic-tangential strategy was associated with favorable functional and quality-of-life outcomes after medial temporal AVM resection. These benefits are likely to be attributable to minimization of temporal retraction, avoidance of brain transgression, and avoidance of traction on the vein of Labbé, rendering the orbitozygomatic-tangential approach the preferred option for cases that are anatomically amenable to either strategy.