Laser interstitial thermal therapy for medically intractable mesial temporal lobe epilepsy

Accounting for repeat intervention costs in the economic comparison of laser interstitial thermal therapy and anterior temporal lobectomy for treatment of refractory temporal lobe epilepsy

OBJECTIVE

Laser interstitial thermal therapy (LITT) is an alternative to anterior temporal lobectomy (ATL) for the treatment of temporal lobe epilepsy that has been found by some to have a lower procedure cost but is generally regarded as less effective and sometimes results in a subsequent procedure. The goal of this study is to incorporate subsequent procedures into the cost and outcome comparison between ATL and LITT.

METHODS

This single-center, retrospective cohort study includes 85 patients undergoing ATL or LITT for temporal lobe epilepsy during the period September 2015 to December 2022. Of the 40 patients undergoing LITT, 35 % (N = 14) underwent a subsequent ATL. An economic cost model is derived, and difference in means tests are used to compare the costs, outcomes, and other hospitalization measures.

RESULTS

Our model predicts that whenever the percentage of LITT patients undergoing subsequent ATL (35% in our sample) exceeds the percentage by which the LITT procedure alone is less costly than ATL (7.2% using total patient charges), LITT will have higher average patient cost than ATL, and this is indeed the case in our sample. After accounting for subsequent surgeries, the average patient charge in the LITT sample ($103,700) was significantly higher than for the ATL sample ($88,548). A second statistical comparison derived from our model adjusts for the difference in effectiveness by calculating the cost per seizure-free patient outcome, which is $108,226 for ATL, $304,052 for LITT only, and $196,484 for LITT after accounting for the subsequent ATL surgeries.

SIGNIFICANCE

After accounting for the costs of subsequent procedures, we found in our cohort that LITT is not only less effective but also results in higher average costs per patient than ATL as a first course of treatment. While cost and effectiveness rates will vary across centers, we also provide a model for calculating cost effectiveness based on individual center data.

A Potential Risk of Radiation-Induced Cavernous Malformations Following Adjuvant Gamma Knife Radiosurgery for Mesial Temporal Lobe Epilepsy

OBJECTIVE

Several clinical studies have explored the feasibility and efficacy of radiosurgical treatment for mesial temporal lobe epilepsy, but the long-term safety of this treatment has not been fully characterized. This study aims to report and describe radiation-induced cavernous malformation as a delayed complication of radiosurgery in epilepsy patients.

METHODS

The series includes 20 patients with mesial temporal lobe epilepsy who underwent Gamma Knife radiosurgery (GKRS). The majority received a prescribed isodose of 24 Gy as an adjuvant treatment after anterior temporal lobectomy.

RESULTS

In this series, we identified radiation-induced cavernous malformation in three patients, resulting in a cumulative incidence of 18.4% (95% confidence interval, 6.3% to 47.0%) at an 8-year follow-up. These late sequelae of vascular malformation occurred between 6.9 and 7.6 years after GKRS, manifesting later than other delayed radiation-induced changes, such as radiation necrosis. Neurological symptoms attributed to intracranial hypertension were present in those three cases involving cavernous malformation. Of these, two cases, which initially exhibited an insufficient response to radiosurgery, ultimately demonstrated seizure remission following the successful microsurgical resection of the cavernous malformation.

CONCLUSION

All things considered, the development of radiation-induced cavernous malformation is not uncommon in this population and should be acknowledged as a potential long-term complication. Microsurgical resection of cavernous malformation can be preferentially considered in cases where the initial seizure outcome after GKRS is unsatisfactory.

EEG Ictal Power Dynamics, Function-Structure Associations, and Epilepsy Surgical Outcomes

BACKGROUND AND OBJECTIVES

Postoperative seizure control in drug-resistant temporal lobe epilepsy (TLE) remains variable, and the causes for this variability are not well understood. One contributing factor could be the extensive spread of synchronized ictal activity across networks. Our study used novel quantifiable assessments from intracranial EEG (iEEG) to test this hypothesis and investigated how the spread of seizures is determined by underlying structural network topological properties.

METHODS

We evaluated iEEG data from 157 seizures in 27 patients with TLE: 100 seizures from 17 patients with postoperative seizure control (Engel score I) vs 57 seizures from 10 patients with unfavorable surgical outcomes (Engel score II-IV). We introduced a quantifiable method to measure seizure power dynamics within anatomical regions, refining existing seizure imaging frameworks and minimizing reliance on subjective human decision-making. Time-frequency power representations were obtained in 6 frequency bands ranging from theta to gamma. Ictal power spectrums were normalized against a baseline clip taken at least 6 hours away from ictal events. Electrodes' time-frequency power spectrums were then mapped onto individual T1-weighted MRIs and grouped based on a standard brain atlas. We compared spatiotemporal dynamics for seizures between groups with favorable and unfavorable surgical outcomes. This comparison included examining the range of activated brain regions and the spreading rate of ictal activities. We then evaluated whether regional iEEG power values were a function of fractional anisotropy (FA) from diffusion tensor imaging across regions over time.

RESULTS

Seizures from patients with unfavorable outcomes exhibited significantly higher maximum activation sizes in various frequency bands. Notably, we provided quantifiable evidence that in seizures associated with unfavorable surgical outcomes, the spread of beta-band power across brain regions is significantly faster, detectable as early as the first second after seizure onset. There was a significant correlation between beta power during seizures and FA in the corresponding areas, particularly in the unfavorable outcome group. Our findings further suggest that integrating structural and functional features could improve the prediction of epilepsy surgical outcomes.

DISCUSSION

Our findings suggest that ictal iEEG power dynamics and the structural-functional relationship are mechanistic factors associated with surgical outcomes in TLE.

Impact of white matter networks on risk for memory decline following resection versus ablation in temporal lobe epilepsy

BACKGROUND

With expanding neurosurgical options in epilepsy, it is important to characterise each options' risk for postoperative cognitive decline. Here, we characterise how patients' preoperative white matter (WM) networks relates to postoperative memory changes following different epilepsy surgeries.

METHODS

Eighty-nine patients with temporal lobe epilepsy with T1-weighted and diffusion-weighted imaging as well as preoperative and postoperative verbal memory scores (prose recall) underwent either anterior temporal lobectomy (ATL: n=38) or stereotactic laser amygdalohippocampotomy (SLAH; n=51). We computed laterality indices (ie, asymmetry) for volume of the hippocampus and fractional anisotropy (FA) of two deep WM tracts (uncinate fasciculus (UF) and inferior longitudinal fasciculus (ILF)).

RESULTS

Preoperatively, left-lateralised FA of the ILF was associated with higher prose recall (p<0.01). This pattern was not observed for the UF or hippocampus (ps>0.05). Postoperatively, right-lateralised FA of the UF was associated with less decline following left ATL (p<0.05) but not left SLAH (p>0.05), while right-lateralised hippocampal asymmetry was associated with less decline following both left ATL and SLAH (ps<0.05). After accounting for preoperative memory score, age of onset and hippocampal asymmetry, the association between UF and memory decline in left ATL remained significant (p<0.01).

CONCLUSIONS

Asymmetry of the hippocampus is an important predictor of risk for memory decline following both surgeries. However, asymmetry of UF integrity, which is only severed during ATL, is an important predictor of memory decline after ATL only. As surgical procedures and pre-surgical mapping evolve, understanding the role of frontal-temporal WM in memory networks could help to guide more targeted surgical approaches to mitigate cognitive decline.

Stereo-electroencephalography-guided three-dimensional radiofrequency thermocoagulation for mesial temporal lobe epilepsy with hippocampal sclerosis: A retrospective study with long-term follow-up

OBJECTIVE

Stereo-electroencephalography-guided three-dimensional radiofrequency thermocoagulation (SEEG-3D RFTC) is a minimally invasive treatment for mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). This study aimed to investigate the long-term prognosis after SEEG-3D RFTC treatment in patients with MTLE-HS.

METHODS

This single-center retrospective study included 28 patients with MTLE-HS treated with SEEG-3D RFTC from January 2016 to May 2018. Postoperative curative effects were evaluated using the Engel classification, and the patients were followed up for 5 years.

RESULTS

The proportions of patients categorized as Engel I between 1 and 5 years after surgery were 72.41% (12 months after surgery), 67.86% (18 months after surgery), 62.07% (24 months after surgery), 50.00% (36 months after surgery), 42.86% (48 months after surgery), and 42.86% (60 months after surgery), respectively. Regarding long-term efficacy, based on the Engel classification, SEEG-3D RFTC showed room for improvement.

SIGNIFICANCE

This was the first study to evaluate the efficacy of SEEG-3D RFTC for MTLE-HS with long-term follow-up. SEEG-3D RFTC is a promising alternative for patients with MTLE-HS.

PLAIN LANGUAGE SUMMARY

This study explored the potential of stereoelectroencephalography-guided three-dimensional radiofrequency thermocoagulation, a minimally invasive approach, for treating medial temporal lobe epilepsy with hippocampal sclerosis. Involving 28 patients, the research tracked the treatment's success over five years using the Engel classification. Initial results were promising, with 72.41% of patients achieving the most favorable outcome (Engel I) at one year. While there was a gradual decrease in this proportion over time, 42.86% of patients maintained this positive outcome at five years, highlighting the treatment's potential for long-term efficacy.

Comparison of minimally invasive to standard temporal lobectomy approaches to epilepsy surgery: Seizure relief and visual confrontation naming outcomes

The purpose of this study was to systematically examine three different surgical approaches in treating left medial temporal lobe epilepsy (mTLE) (viz., subtemporal selective amygdalohippocampectomy [subSAH], stereotactic laser amygdalohippocampotomy [SLAH], and anterior temporal lobectomy [ATL]), to determine which procedures are most favorable in terms of visual confrontation naming and seizure relief outcome. This was a retrospective study of 33 adults with intractable mTLE who underwent left temporal lobe surgery at three different epilepsy surgery centers who also underwent pre-, and at least 6-month post-surgical neuropsychological testing. Measures included the Boston Naming Test (BNT) and the Engel Epilepsy Surgery Outcome Scale. Fisher's exact tests revealed a statistically significant decline in naming in ATLs compared to SLAHs, but no other significant group differences. 82% of ATL and 36% of subSAH patients showed a significant naming decline whereas no SLAH patient (0%) had a significant naming decline. Significant postoperative naming improvement was seen in 36% of SLAH patients in contrast to 9% improvement in subSAH patients and 0% improvement in ATLs. Finally, there were no statistically significant differences between surgical approaches with regard to seizure freedom outcome, although there was a trend towards better seizure relief outcome among the ATL patients. Results support a possible benefit of SLAH in preserving visual confrontation naming after left TLE surgery. While result interpretation is limited by the small sample size, findings suggest outcome is likely to differ by surgical approach, and that further research on cognitive and seizure freedom outcomes is needed to inform patients and providers of potential risks and benefits with each.

Circumscribing Laser Cuts Attenuate Seizure Propagation in a Mouse Model of Focal Epilepsy

In partial onset epilepsy, seizures arise focally in the brain and often propagate. Patients frequently become refractory to medical management, leaving neurosurgery, which can cause neurologic deficits, as a primary treatment. In the cortex, focal seizures spread through horizontal connections in layers II/III, suggesting that severing these connections can block seizures while preserving function. Focal neocortical epilepsy is induced in mice, sub-surface cuts are created surrounding the seizure focus using tightly-focused femtosecond laser pulses, and electrophysiological recordings are acquired at multiple locations for 3-12 months. Cuts reduced seizure frequency in most animals by 87%, and only 5% of remaining seizures propagated to the distant electrodes, compared to 80% in control animals. These cuts produced a modest decrease in cortical blood flow that recovered and left a ≈20-µm wide scar with minimal collateral damage. When placed over the motor cortex, cuts do not cause notable deficits in a skilled reaching task, suggesting they hold promise as a novel neurosurgical approach for intractable focal cortical epilepsy.

The fasciola cinereum of the hippocampal tail as an interventional target in epilepsy

Targeted tissue ablation involving the anterior hippocampus is the standard of care for patients with drug-resistant mesial temporal lobe epilepsy. However, a substantial proportion continues to suffer from seizures even after surgery. We identified the fasciola cinereum (FC) neurons of the posterior hippocampal tail as an important seizure node in both mice and humans with epilepsy. Genetically defined FC neurons were highly active during spontaneous seizures in epileptic mice, and closed-loop optogenetic inhibition of these neurons potently reduced seizure duration. Furthermore, we specifically targeted and found the prominent involvement of FC during seizures in a cohort of six patients with epilepsy. In particular, targeted lesioning of the FC in a patient reduced the seizure burden present after ablation of anterior mesial temporal structures. Thus, the FC may be a promising interventional target in epilepsy.

Impact of intracranial subclinical seizures on seizure outcomes after SLAH in patients with mesial temporal lobe epilepsy

OBJECTIVE

To investigate the association between subclinical seizures detected on intracranial electroencephalographic (i-SCSs)recordings and mesial temporal sclerosis (MTS), as well as their impact on surgical outcomes of stereotactic laser amygdalohippocampotomy (SLAH).

METHODS

A retrospective review was conducted on 27 patients with drug-resistant mesial temporal lobe epilepsy (MTLE) who underwent SLAH. The number of seizures detected on scalp EEG and iEEG was assessed. Patients were followed for a minimum of 3 years after SLAH.

RESULTS

Of the 1715 seizures recorded from mesial temporal regions, 1640 were identified as i-SCSs. Patients with MTS were associated with favorable short- and long-term surgical outcomes. Patients with MTS had a higher number of i-SCSs compared to patients without MTS. The numbers of i-SCSs were higher in patients with Engel I-II outcomes, but no significant statistical difference was found. However, it was observed that patients with MTS who achieved Engel I-II classification had higher numbers of i-SCSs than patients without MTS (P < 0.05).

CONCLUSION

Patients with MTS exhibited favorable short-term and long-term surgical outcome after SLAH. A higher number of i-SCSs was significantly associated with MTS in patients with MTLE. The number of i-SCSs tended to be higher in patients with Engel Ⅰ-Ⅱ surgical outcomes.

SIGNIFICANCE

The association between i-SCSs, MTS, and surgical outcomes in MTLE patients undergoing SLAH has significant implications for understanding the underlying mechanisms and identifying potential therapeutic targets to enhance surgical outcomes.

Predictors of seizure outcomes in stereo-electroencephalography-guided radio-frequency thermocoagulation for MRI-negative epilepsy

Background

One-third of intractable epilepsy patients have no visually identifiable focus for neurosurgery based on imaging tests [magnetic resonance imaging (MRI)-negative cases]. Stereo-electroencephalography-guided radio-frequency thermocoagulation (SEEG-guided RF-TC) is utilized in the clinical treatment of epilepsy to lower the incidence of complications post-open surgery.

Objective

This study aimed to identify prognostic factors and long-term seizure outcomes in SEEG-guided RF-TC for patients with MRI-negative epilepsy.

Design

This was a single-center retrospective cohort study.

Methods

We included 30 patients who had undergone SEEG-guided RF-TC at Sanbo Brain Hospital, Capital Medical University, from April 2015 to December 2019. The probability of remaining seizure-free and the plotted survival curves were analyzed. Prognostic factors were analyzed using log-rank tests in univariate analysis and the Cox regression model in multivariate analysis.

Results

With a mean time of 31.07 ± 2.64 months (median 30.00, interquartile range: 18.00-40.00 months), 11 out of 30 patients (36.7%) were classified as International League Against Epilepsy class 1 in the last follow-up. The mean time of remaining seizure-free was 21.33 ± 4.55 months [95% confidence interval (CI) 12.41-30.25], and the median time was 3.00 ± 0.54 months (95% CI 1.94-4.06). Despite falling in the initial year, the probability of remaining seizure-free gradually stabilizes in the subsequent years. The patients were more likely to obtain seizure freedom when the epileptogenic zone was located in the insular lobe or with one focus on the limbic system (p = 0.034, hazard ratio 5.019, 95% CI 1.125-22.387).

Conclusion

Our findings may be applied to guide individualized surgical interventions and help clinicians make better decisions.

Magnetic resonance-guided laser interstitial thermal therapy vs. open surgery for drug-resistant mesial temporal lobe epilepsy: a propensity score matched retrospective cohort study

BACKGROUND

Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) and traditional open surgery (OS) are effective and safe options for patients with drug-resistant mesial temporal lobe epilepsy (DR-mTLE). However, their superiority in seizure control and preservation of functional abilities remains unclear. This study aimed to compare the surgical outcomes of MRgLITT and OS.

MATERIALS AND METHODS

This multicenter retrospective cohort study included patients with DR-mTLE who underwent MRgLITT or OS at three centres between 2015 and 2023. The data on patient demographics, presurgical non-invasive evaluation, stereoelectroencephalography (SEEG) implantation, memory alteration, and seizure outcomes were collected. Propensity score matching (PSM) analysis was conducted for the comparison of seizure control and functional preservation between two surgical approaches.

RESULTS

Of the 244 individuals who met the study criteria, 33 underwent MRgLITT and 211 OS. The median (interquartile range) age at seizure onset was 22.0 (13.0) and 12.3 (10.0) years in the MRgLITT and OS groups, respectively. The first PSM, based on demographic and non-invasive information, resulted in 26 matched pairs for the primary analysis. There were no significant differences in memory preservation ( P = 0.95) or surgical outcomes ( P = 0.96) between the groups. The second PSM, based on demographics and SEEG implantation, yielded 32 matched pairs for the sensitivity analysis, showing similar results. Subset analysis of early and late MRgLITT cases revealed no statistically significant differences in the proportion of patients with memory decline ( P = 0.42) or seizure control ( P = 1.00). Patients who underwent SEEG implantation were 96% less likely to achieve seizure freedom after MRgLITT ( P = 0.02).

CONCLUSION

Minimally invasive MRgLITT is associated with memory preservation and seizure control, similar to traditional OS. MRgLITT is effective and safe for DR-mTLE and is relevant for future prospective randomized trials on dominant-side mTLE, providing practical implications for guiding neurosurgeons in the selection of surgical approaches.

Advancements in Glioma Care: Focus on Emerging Neurosurgical Techniques

BACKGROUND

Despite significant advances in understanding the molecular pathways of glioma, translating this knowledge into effective long-term solutions remains a challenge. Indeed, gliomas pose a significant challenge to neurosurgical oncology because of their diverse histopathological features, genetic heterogeneity, and clinical manifestations. Relevant sections: This study focuses on glioma complexity by reviewing recent advances in their management, also considering new classification systems and emerging neurosurgical techniques. To bridge the gap between new neurosurgical approaches and standards of care, the importance of molecular diagnosis and the use of techniques such as laser interstitial thermal therapy (LITT) and focused ultrasound (FUS) are emphasized, exploring how the integration of molecular knowledge with emerging neurosurgical approaches can personalize and improve the treatment of gliomas.

CONCLUSIONS

The choice between LITT and FUS should be tailored to each case, considering factors such as tumor characteristics and patient health. LITT is favored for larger, complex tumors, while FUS is standard for smaller, deep-seated ones. Both techniques are equally effective for small and superficial tumors. Our study provides clear guidance for treating pediatric low-grade gliomas and highlights the crucial roles of LITT and FUS in managing high-grade gliomas in adults. This research sets the stage for improved patient care and future developments in the field of neurosurgery.

Interictal intracranial EEG asymmetry lateralizes temporal lobe epilepsy

Patients with drug-resistant temporal lobe epilepsy often undergo intracranial EEG recording to capture multiple seizures in order to lateralize the seizure onset zone. This process is associated with morbidity and often ends in postoperative seizure recurrence. Abundant interictal (between-seizure) data is captured during this process, but these data currently play a small role in surgical planning. Our objective was to predict the laterality of the seizure onset zone using interictal (between-seizure) intracranial EEG data in patients with temporal lobe epilepsy. We performed a retrospective cohort study (single-center study for model development; two-center study for model validation). We studied patients with temporal lobe epilepsy undergoing intracranial EEG at the University of Pennsylvania (internal cohort) and the Medical University of South Carolina (external cohort) between 2015 and 2022. We developed a logistic regression model to predict seizure onset zone laterality using interictal EEG. We compared the concordance between the model-predicted seizure onset zone laterality and the side of surgery between patients with good and poor surgical outcomes. 47 patients (30 women; ages 20-69; 20 left-sided, 10 right-sided, and 17 bilateral seizure onsets) were analyzed for model development and internal validation. 19 patients (10 women; ages 23-73; 5 left-sided, 10 right-sided, 4 bilateral) were analyzed for external validation. The internal cohort cross-validated area under the curve for a model trained using spike rates was 0.83 for a model predicting left-sided seizure onset and 0.68 for a model predicting right-sided seizure onset. Balanced accuracies in the external cohort were 79.3% and 78.9% for the left- and right-sided predictions, respectively. The predicted concordance between the laterality of the seizure onset zone and the side of surgery was higher in patients with good surgical outcome. In conclusion, interictal EEG signatures are distinct across seizure onset zone lateralities. Left-sided seizure onsets are easier to distinguish than right-sided onsets. A model trained on spike rates accurately identifies patients with left-sided seizure onset zones and predicts surgical outcome.

Value of ultralong-term subcutaneous EEG monitoring for treatment decisions in temporal lobe epilepsy: A case report

Treatment decisions in epilepsy critically depend on information on the course of the disease, its severity and options for specific local interventions. We here report a patient with pharmaco-resistant non-lesional temporal lobe epilepsy with evidence for predominant right temporal epileptogenesis. While seizure frequency had been grossly underestimated for many years, ultralong-term monitoring with a subcutaneous EEG device revealed actual seizure frequency (66 over 11 months vs four patient-documented seizures), providing objective data on treatment efficacy and additional supportive lateralizing information that played a decisive role for the choice of surgical treatment, which had been rejected by the patient prior to this information.

Long-term outcomes of mesial temporal laser interstitial thermal therapy for drug-resistant epilepsy and subsequent surgery for seizure recurrence: a multi-centre cohort study

BACKGROUND

Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive alternative to surgical resection for drug-resistant mesial temporal lobe epilepsy (mTLE). Reported rates of seizure freedom are variable and long-term durability is largely unproven. Anterior temporal lobectomy (ATL) remains an option for patients with MRgLITT treatment failure. However, the safety and efficacy of this staged strategy is unknown.

METHODS

This multicentre, retrospective cohort study included 268 patients consecutively treated with mesial temporal MRgLITT at 11 centres between 2012 and 2018. Seizure outcomes and complications of MRgLITT and any subsequent surgery are reported. Predictive value of preoperative variables for seizure outcome was assessed.

RESULTS

Engel I seizure freedom was achieved in 55.8% (149/267) at 1 year, 52.5% (126/240) at 2 years and 49.3% (132/268) at the last follow-up ≥1 year (median 47 months). Engel I or II outcomes were achieved in 74.2% (198/267) at 1 year, 75.0% (180/240) at 2 years and 66.0% (177/268) at the last follow-up. Preoperative focal to bilateral tonic-clonic seizures were independently associated with seizure recurrence. Among patients with seizure recurrence, 14/21 (66.7%) became seizure-free after subsequent ATL and 5/10 (50%) after repeat MRgLITT at last follow-up≥1 year.

CONCLUSIONS

MRgLITT is a viable treatment with durable outcomes for patients with drug-resistant mTLE evaluated at a comprehensive epilepsy centre. Although seizure freedom rates were lower than reported with ATL, this series represents the early experience of each centre and a heterogeneous cohort. ATL remains a safe and effective treatment for well-selected patients who fail MRgLITT.

Progress in TLE treatment from 2003 to 2023: scientific measurement and visual analysis based on CiteSpace

Objective

Temporal lobe epilepsy (TLE) is the most common cause of drug-resistant epilepsy and can be treated surgically to control seizures. In this study, we analyzed the relevant research literature in the field of temporal lobe epilepsy (TLE) treatment to understand the background, hotspots, and trends in TLE treatment research.

Methods

We discussed the trend, frontier, and hotspot of scientific output in TLE treatment research in the world in the last 20 years by searching the core collection of the Web of Science database. Excel and CiteSpace software were used to analyze the basic data of the literature.

Result

We identified a total of 2,051 publications on TLE treatment from 75 countries between 2003 and 2023. We found that the publication rate was generally increasing. The United States was the most publishing country; among the research institutions on TLE treatment, the University of California system published the most relevant literature and collaborated the most with other institutions. The co-citation of literature, keyword co-occurrence, and its clustering analysis showed that the early studies focused on open surgical treatment, mainly by lobectomy. In recent years, the attention given to stereotactic, microsurgery, and other surgical techniques has gradually increased, and the burst analysis indicated that new research hotspots may appear in the future in the areas of improved surgical procedures and mechanism research.

Outcomes after laser interstitial thermal ablation for temporal lobe epilepsy: a systematic review and meta-analysis

Epilepsy is a common condition that affects approximately 1% of the world's population, with about one-third being refractory epilepsy. Temporal lobe epilepsy is the most common type of drug-resistant epilepsy, and laser interstitial thermal therapy (LITT) is an innovative treatment. In this systematic review and meta-analysis, we aimed to summarize the current evidence on outcomes after LITT, including seizure freedom rate, complication rate, and neurocognitive outcome. PubMed and OVID Medline search engines were systematically searched for all indexed publications in the English language up to July15, 2023. The search was limited to human studies. Proportions and 95% confidence interval (CI) values were calculated for seizure, neurocognitive outcome, and complication rate. A total of 836 patients were included. Overall seizure outcomes, regardless of the pathology, included Engel I outcome in 56% (95% CI, 52.4-59.5%), Engel II outcome in 19.2% (95% CI, 15.4-23.6%), Engel III outcome in 17.3% (95% CI, 13.5-21.8%), and Engel IV outcome in 10.5% (95% CI 6.3-17%) of the patients. The overall decline in verbal and visual memory regardless of laterality was 24.2 (95% CI 8.6-52%) and 25.2% (8.3-55.8%). For naming, the decline was 13.4% (6.6-25.4%). The results of the pooled analysis in comparison with available data in the literature showed that seizure outcomes after LITT were slightly inferior to published data after temporal lobectomy. Data on cognitive outcomes after LITT are scarce and heterogeneous.

Intraventricular SEEG and laser ablation for the treatment of infantile spasm: Technical note

OBJECTIVES

Infantile spasm (IS) is an epileptic encephalopathy with ongoing neurological damage due to seizures and epileptiform abnormalities. Epilepsy surgery is considered for children refractory to drug therapy, especially when there is a focal brain lesion. In this study, we investigated the feasibility and efficacy of intraventricular stereotactic electroencephalography (SEEG) and laser ablation for the treatment of IS children with focal brain lesions.

METHODS

We performed the first reported study using ventriculoscopic laser ablation to treat IS. Seven IS children with drug-resistant epilepsy and definite encephalomalacia on brain magnetic resonance imaging scan were included in this study. Ablation was performed after confirmation of epileptiform discharges by SEEG under the surveillance of ventriculoscope.

RESULTS

The median follow-up time for the cohort was 3.1 years and 86% (6/7) of the children had an Engel class ≤III epilepsy at the final follow-up. Five (71%) children had a reduction in seizure medication usage, and the other two were on the same amount as preablation. None of the children experienced serious new neurological deficits. Laser ablation might result in seizure freedom by destroying the local brain network and blocking the spread of abnormal discharges.

CONCLUSIONS

Intraventricular SEEG and laser ablation was feasible and effective for the treatment of IS. Further studies are warranted.

Seizure and anatomical outcomes of repeat laser amygdalohippocampotomy for temporal lobe epilepsy: A single-institution case series

OBJECTIVE

In patients with treatment-refractory temporal lobe epilepsy (TLE), a single stereotactic laser interstitial thermotherapy (LITT) procedure is sometimes insufficient to ablate epileptogenic tissue, particularly the medial structures often implicated in TLE. In patients with seizure recurrence after initial ablation, the extent to which a second ablation may achieve improved seizure outcomes is uncertain. The objective of this study was to investigate the feasibility and potential efficacy of repeat LITT amygdalohippocampotomy as a worthwhile strategy for intractable temporal lobe epilepsy by quantifying changes to targeted mesial temporal lobe structures and seizure outcomes.

METHODS

Patients who underwent two LITT procedures for drug-resistant mesial TLE at our institution were included in the study. Lesion volumes for both procedures were calculated by comparing post-ablation intraoperative sequences to preoperative anatomy. Clinical outcomes after the initial procedure and repeat procedure were classified according to Engel scores.

RESULTS

Five consecutive patients were included in this retrospective case series: 3 with right- and 2 with left-sided TLE. The median interval between LITT procedures was 294 days (range: 227-1918). After the first LITT, 3 patients experienced class III outcomes, 1 experienced a class IV, and 1 experienced a class IB outcome. All patients achieved increased seizure freedom after a second procedure, with class I outcomes (3 IA, 2 IB).

CONCLUSIONS

Repeat LITT may be sufficient to achieve satisfactory seizure outcomes in some individuals who might otherwise be considered for more aggressive resection or palliative neuromodulation. A larger study to establish the potential value of repeat LITT amygdalohippocampotomy vs. other re-operation strategies for persistent, intractable temporal lobe epilepsy is worth pursuing.

A cost analysis of MR-guided laser interstitial thermal therapy for adult refractory epilepsy

OBJECTIVE

MR-guided laser interstitial thermal therapy (LITT) is used increasingly for refractory epilepsy. The goal of this investigation is to directly compare cost and short-term adverse outcomes for adult refractory epilepsy treated with temporal lobectomy and LITT, as well as to identify risk factors for increased costs and adverse outcomes.

METHODS

The National Inpatient Sample (NIS) was queried for patients who received LITT between 2012 and 2019. Patients with adult refractory epilepsy were identified. Multivariable mixed-effects models were used to analyze predictors of cost, length of stay (LOS), and complications.

RESULTS

LITT was associated with reduced LOS and overall cost relative to temporal lobectomy, with a statistical trend toward lower incidence of postoperative complications. High-volume surgical epilepsy centers had lower LOS overall. Longer LOS was a significant driver of increased cost for LITT, and higher comorbidity was associated with non-routine discharge.

SIGNIFICANCE

LITT is an affordable alternative to temporal lobectomy for adult refractory epilepsy with an insignificant reduction in inpatient complications. Patients may benefit from expanded access to this treatment modality for both its reduced LOS and lower cost.

Magnetic resonance-guided laser interstitial thermal therapy for drug-resistant epilepsy: A systematic review and individual participant data meta-analysis

Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has emerged as a popular minimally invasive alternative to open resective surgery for drug-resistant epilepsy (DRE). We sought to perform a systematic review and individual participant data meta-analysis to identify independent predictors of seizure outcome and complications following MRgLITT for DRE. Eleven databases were searched from January 1, 2010 to February 6, 2021 using the terms "MR-guided ablation therapy" and "epilepsy". Multivariable mixed-effects Cox and logistic regression identified predictors of time to seizure recurrence, seizure freedom, operative complications, and postoperative neurological deficits. From 8705 citations, 46 studies reporting on 450 MRgLITT DRE patients (mean age = 29.5 ± 18.1 years, 49.6% female) were included. Median postoperative seizure freedom and follow-up duration were 15.5 and 19.0 months, respectively. Overall, 240 (57.8%) of 415 patients (excluding palliative corpus callosotomy) were seizure-free at last follow-up. Generalized seizure semiology (hazard ratio [HR] = 1.78, p = .020) and nonlesional magnetic resonance imaging (MRI) findings (HR = 1.50, p = .032) independently predicted shorter time to seizure recurrence. Cerebral cavernous malformation (CCM; odds ratio [OR] = 7.97, p < .001) and mesial temporal sclerosis/atrophy (MTS/A; OR = 2.21, p = .011) were independently associated with greater odds of seizure freedom at last follow-up. Operative complications occurred in 28 (8.5%) of 330 patients and were independently associated with extratemporal ablations (OR = 5.40, p = .012) and nonlesional MRI studies (OR = 3.25, p = .017). Postoperative neurological deficits were observed in 53 (15.1%) of 352 patients and were independently predicted by hypothalamic hamartoma etiology (OR = 5.93, p = .006) and invasive electroencephalographic monitoring (OR = 4.83, p = .003). Overall, MRgLITT is particularly effective in treating patients with well-circumscribed lesional DRE, such as CCM and MTS/A, but less effective in nonlesional cases or lesional cases with a more diffuse epileptogenic network associated with generalized seizures. This study identifies independent predictors of seizure freedom and complications following MRgLITT that may help further guide patient selection.

Psychiatric changes after stereotactic laser amygdalohippocampotomy for medial temporal lobe epilepsy

PURPOSE

Stereotactic laser amygdalohippocampotomy (SLAH) is a minimally invasive surgical treatment for drug-resistant temporal lobe epilepsy (TLE) that has comparable rates of seizure freedom to traditional open resective TLE surgery. The objective of this study was to determine psychiatric outcome (i.e., depression and anxiety changes, psychosis) after SLAH, to explore possible contributory factors to these changes, and to determine the prevalence of de novo psychopathology.

METHODS

We explored mood and anxiety in 37 adult patients with TLE undergoing SLAH using the Beck psychiatric symptoms scales (i.e., Beck Depression Inventory-II [BDI-II] and Beck Anxiety Inventory [BAI]) preoperatively and 6 months following surgery. Multivariable regression analysis was conducted to identify predictors of worse depression or anxiety symptoms following SLAH. The prevalence of de novo psychopathology following SLAH was also determined.

RESULTS

We found a significant decrease in BDI-II (mean decline from 16.3 to 10.9, p = 0.004) and BAI (mean decline from 13.3 to 9.0, p = 0.045) scores following SLAH at the group level. While the rate of resolution of depression (from 62% to 49%) did not achieve statistical significance (p = 0.13, McNemar's), the rate of resolution of anxiety (from 57% to 35%) was statistically significant (p = 0.03, McNemar's). The de novo rate of psychopathology (i.e., new onset depression or anxiety) following SLAH was 1 of 7 (14%). Using a metric of meaningful change rather than complete symptom resolution, 16 of 37 (43%) patients experienced improvement in depression and 6 of 37 (16%) experienced worsening. For anxiety, 14 of 37 (38%) experienced meaningful improvement and 8 of 37 (22%) experienced worsening. Baseline performance on the Beck Scales was the only factor contributing to outcome status.

DISCUSSION

In one of the first studies to evaluate psychiatric outcomes after SLAH, we found promising overall trends toward stability or significant improvement in symptom burden at the group level for both depression and anxiety. There was also a significant improvement in clinical anxiety, though the decrease in clinical depression was not significant, likely owing to the limitations of sample size. SLAH may improve overall psychiatric symptoms, similarly to traditional resective TLE surgery, but de novo psychopathology and postoperative psychiatric morbidity remain significant issues, and larger samples are necessary to determine causal contributory factors.

Automated subfield volumetric analysis of amygdala, hippocampus, and thalamic nuclei in mesial temporal lobe epilepsy

Purpose

Identifying relationships between clinical features and quantitative characteristics of the amygdala-hippocampal and thalamic subregions in mesial temporal lobe epilepsy (mTLE) may offer insights into pathophysiology and the basis for imaging prognostic markers of treatment outcome. Our aim was to ascertain different patterns of atrophy or hypertrophy in mesial temporal sclerosis (MTS) patients and their associations with post-surgical seizure outcomes. To assess this aim, this study is designed in 2 folds: (1) hemispheric changes within MTS group and (2) association with postsurgical seizure outcomes.

Methods and materials

27 mTLE subjects with mesial temporal sclerosis (MTS) were scanned for conventional 3D T1w MPRAGE images and T2w scans. With respect to 12 months post-surgical seizure outcomes, 15 subjects reported being seizure free (SF) and 12 reported continued seizures. Quantitative automated segmentation and cortical parcellation were performed using Freesurfer. Automatic labeling and volume estimation of hippocampal subfields, amygdala, and thalamic subnuclei were also performed. The volume ratio (VR) for each label was computed and compared between (1) between contralateral and ipsilateral MTS using Wilcoxon rank-sum test and (2) SF and not seizure free (NSF) groups using linear regression analysis. False Discovery rate (FDR) with significant level of 0.05 were used in both analyses to correct for multiple comparisons.

Results

Amygdala: The medial nucleus of the amygdala was the most significantly reduced in patients with continued seizures when compared to patients who remained seizure free. Hippocampus: Comparison of ipsilateral and contralateral volumes with seizure outcomes showed volume loss was most evident in the mesial hippocampal regions such as CA4 and hippocampal fissure. Volume loss was also most explicit in the presubiculum body in patients with continued seizures at the time of their follow-up. Ipsilateral MTS compared to contralateral MTS analysis showed the heads of the ipsilateral subiculum, presubiculum, parasubiculum, dentate gyrus, CA4, and CA3 were more significantly affected than their respective bodies. Volume loss was most noted in mesial hippocampal regions. Thalamus: VPL and PuL were the most significantly reduced thalamic nuclei in NSF patients. In all statistically significant areas, volume reduction was observed in the NSF group. No significant volume reductions were noted in the thalamus and amygdala when comparing ipsilateral to contralateral sides in mTLE subjects.

Conclusions

Varying degrees of volume loss were demonstrated in the hippocampus, thalamus, and amygdala subregions of MTS, especially between patients who remained seizure-free and those who did not. The results obtained can be used to further understand mTLE pathophysiology.

Clinical relevance/application

In the future, we hope these results can be used to deepen the understanding of mTLE pathophysiology, leading to improved patient outcomes and treatments.

Protocol of a prospective multicenter randomized controlled trial of robot-assisted stereotactic lesioning in the treatment of focal drug-resistant epilepsy

BACKGROUND

This protocol describes the design of a multicenter randomized controlled trial of robot-assisted stereotactic lesioning versus epileptogenic foci resection. Typical causes of focal epilepsy include hippocampal sclerosis and focal cortical dysplasia. These patients usually present with drug resistance and require surgical treatment. Although epileptogenic foci resection is still the most commonly used treatment for such focal epilepsy, there is increasing evidence that epileptogenic focus resection may lead to neurological impairment. The treatment of epilepsy with a robot-assisted stereotactic lesioning mainly includes two new minimally invasive surgical methods: radiofrequency thermocoagulation (RF-TC) and laser interstitial thermal therapy (LITT). Seizure-free is less likely to be achieved by these two procedures, but neurologic preservation is better. In this study, we aimed to compare the safety and efficacy of RF-TC, LITT, and epileptogenic foci resection for focal drug-resistant epilepsy.

METHODS

This is a multicenter, three-arm, randomized controlled clinical trial. The study will include patients older than 3 years of age with epilepsy who have had medically refractory seizures for at least 2 years and are eligible for surgical treatment with an epileptogenic focus as determined by multidisciplinary evaluation prior to randomization. The primary outcome measure is seizure outcome (quantified by seizure remission rate) at 3-month, 6-month, and 1-year follow-up after treatment. Postoperative neurologic impairment, spectrum distribution change of video electroencephalogram, quality of life, and medical costs will also be assessed as secondary outcomes.

TRIAL REGISTRATION

Chinese Clinical Trials Registry ChiCTR2200060974. Registered on June 14, 2022. The status of the trial is recruiting, and the estimated study completion date is December 31, 2024.

Tailored Hemispherotomy Using Tractography-Guided Laser Interstitial Thermal Therapy

BACKGROUND

Medically refractory hemispheric epilepsy is a devastating disease with significant lifetime costs and social burden. Functional hemispherotomy is a highly effective treatment for hemispheric epilepsy but is associated with significant complication rates. Percutaneous hemispherotomy through laser interstitial thermal therapy (LITT) based on morphological MRI has been recently described in a single patient but not replicated in the literature.

OBJECTIVE

To describe the first 2 cases of tractography-guided interstitial laser hemispherotomy and their short-term outcomes.

METHODS

Two 11-year-old male patients with medically refractory epilepsy secondary to perinatal large vessel infarcts were referred for hemispherotomy. Both patients underwent multitrajectory LITT to disconnect the remaining pathological hemisphere, using tractography to define targets and assess structural outcomes.

RESULTS

Both cases had minor complication of small intraventricular/subarachnoid hemorrhage not requiring additional intervention. Both patients remain seizure-free at all follow-up visits.

CONCLUSION

LITT hemispherotomy can produce seizure freedom with short hospitalization and recovery. Tractography allows surgical planning to be tailored according to individual patient anatomy, which often is distorted in perinatal stroke. Minimally invasive procedures offer the greatest potential for seizure freedom without the risks of an open hemispherotomy.

Seizure onset patterns predict outcome after stereo-electroencephalography-guided laser amygdalohippocampotomy

OBJECTIVE

Stereotactic laser amygdalohippocampotomy (SLAH) is an appealing option for patients with temporal lobe epilepsy, who often require intracranial monitoring to confirm mesial temporal seizure onset. However, given limited spatial sampling, it is possible that stereotactic electroencephalography (stereo-EEG) may miss seizure onset elsewhere. We hypothesized that stereo-EEG seizure onset patterns (SOPs) may differentiate between primary onset and secondary spread and predict postoperative seizure control. In this study, we characterized the 2-year outcomes of patients who underwent single-fiber SLAH after stereo-EEG and evaluated whether stereo-EEG SOPs predict postoperative seizure freedom.

METHODS

This retrospective five-center study included patients with or without mesial temporal sclerosis (MTS) who underwent stereo-EEG followed by single-fiber SLAH between August 2014 and January 2022. Patients with causative hippocampal lesions apart from MTS or for whom the SLAH was considered palliative were excluded. An SOP catalogue was developed based on literature review. The dominant pattern for each patient was used for survival analysis. The primary outcome was 2-year Engel I classification or recurrent seizures before then, stratified by SOP category.

RESULTS

Fifty-eight patients were included, with a mean follow-up duration of 39 ± 12 months after SLAH. Overall 1-, 2-, and 3-year Engel I seizure freedom probability was 54%, 36%, and 33%, respectively. Patients with SOPs, including low-voltage fast activity or low-frequency repetitive spiking, had a 46% 2-year seizure freedom probability, compared to 0% for patients with alpha or theta frequency repetitive spiking or theta or delta frequency rhythmic slowing (log-rank test, p = .00015).

SIGNIFICANCE

Patients who underwent SLAH after stereo-EEG had a low probability of seizure freedom at 2 years, but SOPs successfully predicted seizure recurrence in a subset of patients. This study provides proof of concept that SOPs distinguish between hippocampal seizure onset and spread and supports using SOPs to improve selection of SLAH candidates.

Transfrontal Approach to the Amygdala for Ablation With Laser Interstitial Thermal Therapy: An Epilepsy Case Report

BACKGROUND AND IMPORTANCE

Stereotactic laser amygdalohippocampotomy (SLAH) using laser interstitial thermal therapy is a minimally invasive surgery used to treat mesial temporal lobe epilepsy. It uses laser probes inserted through occipital and temporo-occipital trajectories to ablate the hippocampus and amygdala. However, these trajectories are limited in their ability to ablate the superior amygdala and entorhinal cortex (ERC). We present a trajectory through the middle frontal gyrus as an alternative to the temporo-occipital trajectory, which provides more complete ablation of the amygdala and anterior ERC through a single pass.

CLINICAL PRESENTATION

A 70-year-old woman with seizures characterized by fear were localized to the left superomedial amygdala on intracranial electroencephalography. They developed after resection of a left temporal arteriovenous malformation and were refractory to medication. Her age and prior craniotomy made open resection less desirable. A frontal and occipital SLAH achieved Engel 1a at 1-year follow-up without decline in neuropsychological performance scores.

CONCLUSION

Typical SLAH uses trajectories that have limited ability to ablate the superior and medial amygdala and ERC in a single passage. A combined approach using an occipital and frontal trajectory allows more complete ablation of the amygdala, hippocampus, and ERC.

Long-term Outcome of Seizure Control and Neurologic Performance After Limited Hippocampal Radiofrequency Thermocoagulation for Mesial Temporal Lobe Epilepsy

OBJECTIVE

Limited hippocampal radiofrequency thermocoagulation (RFTC) for patients with mesial temporal lobe epilepsy was associated with good short-term seizure control and few complications. We aimed to demonstrate the neuropsychologic outcomes and assess the prognostic factors of long-term seizure control in these patients.

METHODS

We included all patients with mesial temporal lobe epilepsy who underwent limited hippocampal RFTC from January 2016 to December 2020. Clinical data of age, sex, seizure control before and after operation were all corrected. Pre- and postoperative neuropsychologic function including full-scale intelligence quotient (FSIQ), memory quotient, and the Mini-Mental State Examination was used.

RESULTS

Thirty-one patients (17 female and 14 male) with a mean epilepsy duration of 22.3 years and seizure frequency of 5.7 times per month were included. The intraoperative seizure rate was 19.3%, and a higher preoperative seizure frequency (P = 0.001) and longer duration of epilepsy (P = 0.042) were associated with the occurrence of intraoperative seizures. The postoperative FSIQ scores were significantly better than preoperative scores (mean 92.1 vs. 89.7, P = 0.014). Nine patients (29%) who underwent limited hippocampal RFTC were seizure-free at 1 year of follow-up. Responders represented 58% (n = 18) of patients at 1 year. The mean follow-up period was 34.7 ± 13.3 months. Five patients remained seizure free and 13 patients are still responders at the last follow-up visits. Long-term seizure frequency was 2.32 ± 2.86 times per month.

CONCLUSIONS

Limited hippocampal RFTC is a safe stereotactic minimal invasive procedure with good neuropsychologic outcome and acceptable efficacy of seizure reduction in appropriately selected patients.

Laser Interstitial Thermal Therapy for Epilepsy

Laser interstitial thermal therapy is an important new technique with a diverse use in epilepsy. This article gives an up-to-date evaluation of the current use of the technique within epilepsy, as well as provides some guidance to novice users appropriate clinical cases for its use.

Feasibility of Transcranial Motor Evoked Potentials and Electromyography during MRI-Guided Laser Interstitial Thermal Therapy for Glioblastoma

BACKGROUND

Intraoperative neuromonitoring (IONM) is routinely used during neurosurgical procedures. Magnetic resonance imaging (MRI)-guided laser interstitial thermal therapy (LITT) is increasingly being used in patients with various brain lesions. Use of IONM (transcranial motor evoked potential [TcMEP] and electromyography [EMG]) during LITT of a brain lesion has not been described previously.

METHODS

In this report, we describe a 70-year-old man who presented with motor weakness in whom imaging revealed a left thalamic lesion. Due to the difficulty in accessing the lesion and proximity to the motor tracts, patient was offered MRI-guided LITT using TcMEP and EMG.

RESULTS

The patient underwent satisfactory ablation of the lesion with successful recording of the TcMEP and EMG. Technical nuances related to the set-up and procedure is discussed in this report. No procedure-related complications were encountered.

CONCLUSIONS

We describe the first report of safety and feasibility of TcMEP and EMG during MRI-guided LITT for left thalamic glioblasatoma. This report paves the way for further prospective investigations regarding the utility of this technique for eloquent brain tumors.

Ablation of apparent diffusion coefficient hyperintensity clusters in mesial temporal lobe epilepsy improves seizure outcomes after laser interstitial thermal therapy

OBJECTIVE

Laser interstitial thermal therapy (LiTT) is a minimally invasive surgical procedure for intractable mesial temporal epilepsy (mTLE). LiTT is safe and effective, but seizure outcomes are highly variable due to patient variability, suboptimal targeting, and incomplete ablation of the epileptogenic zone. Apparent diffusion coefficient (ADC) is a magnetic resonance imaging (MRI) sequence that can identify potential epileptogenic foci in the mesial temporal lobe to improve ablation and seizure outcomes. The objective of this study was to investigate whether ablation of tissue clusters with high ADC values in the mesial temporal structures is associated with seizure outcome in mTLE after LiTT.

METHODS

Twenty-seven patients with mTLE who underwent LiTT at our institution were analyzed. One-year seizure outcome was categorized as complete seizure freedom (International League Against Epilepsy [ILAE] Class I) and residual seizures (ILAE Class II-VI). Volumes of hippocampus and amygdala were segmented from the preoperative T1 MRI sequence. Spatially distinct hyperintensity clusters were identified in the preoperative ADC map. Proportion of cluster volume and number ablated were associated with seizure outcomes.

RESULTS

The mean age at surgery was 37.5 years and the mean follow-up duration was 1.9 years. Proportions of hippocampal cluster volume (p = .013) and number (p = .03) ablated were significantly higher in patients with seizure freedom. For amygdala clusters, the proportion of cluster number ablated was significantly associated with seizure outcome (p = .026). In the combined amygdalohippocampal complex, ablation of amygdalohippocampal clusters reliably predicted seizure outcome by their volume ablated (area under the curve [AUC] = 0.7670, p = .02).

SIGNIFICANCE

Seizure outcome after LiTT in patients with mTLE was associated significantly with the extent of cluster ablation in the amygdalohippocampal complex. The results suggest that preoperative ADC analysis may help identify high-yield pathological tissue clusters that represent epileptogenic foci. ADC-based cluster analysis can potentially assist ablation targeting and improve seizure outcome after LiTT in mTLE.

Epileptic-network-based prediction and control of seizures in humans

Epilepsy is now conceptualized as a network disease. The epileptic brain network comprises structurally and functionally connected cortical and subcortical brain regions - spanning lobes and hemispheres -, whose connections and dynamics evolve in time. With this concept, focal and generalized seizures as well as other related pathophysiological phenomena are thought to emerge from, spread via, and be terminated by network vertices and edges that also generate and sustain normal, physiological brain dynamics. Research over the last years has advanced concepts and techniques to identify and characterize the evolving epileptic brain network and its constituents on various spatial and temporal scales. Network-based approaches further our understanding of how seizures emerge from the evolving epileptic brain network, and they provide both novel insights into pre-seizure dynamics and important clues for success or failure of measures for network-based seizure control and prevention. In this review, we summarize the current state of knowledge and address several important challenges that would need to be addressed to move network-based prediction and control of seizures closer to clinical translation.

Association Between Characteristics of National Association of Epilepsy Centers and Reported Utilization of Specific Surgical Techniques

BACKGROUND AND OBJECTIVE

Nearly one-third of persons with epilepsy will continue having seizures despite trialing multiple antiseizure medications. Epilepsy surgery may be beneficial in these cases, and evaluation at a comprehensive epilepsy center is recommended. Numerous palliative and potentially curative approaches exist, and types of surgery performed may be influenced by center characteristics. This article describes epilepsy center characteristics associated with epilepsy surgery access and volumes in the United States.

METHODS

We analyzed National Association of Epilepsy Centers 2019 annual report and supplemental survey data obtained with responses from 206 adult epilepsy center directors and 136 pediatric epilepsy center directors in the United States. Surgical treatment volumes were compiled with center characteristics, including US Census region. We used multivariable modeling with zero-inflated Poisson regression models to present ORs and incidence rate ratios of receiving a given surgery type based on center characteristics.

RESULTS

The response rate was 100% with individual element missingness less than 4% across 352 observations undergoing univariate analysis. Multivariable models included 319 complete observations. Significant regional differences were present. The rates of laser interstitial thermal therapy (LITT) were lower at centers in the Midwest (incidence rate ratio [IRR] 0.74, 95% CI 0.59-0.92; p = 0.006) and Northeast (IRR 0.77, 95% CI 0.61-0.96; p = 0.022) compared with those in the South. Conversely, responsive neurostimulation implantation rates were higher in the Midwest (IRR 1.45, 95% CI 1.1-1.91; p = 0.008) and West (IRR 1.91, 95% CI 1.49-2.44; p < 0.001) compared with the South. Center accreditation level, institution type, demographics, and resources were also associated with variations in access and rates of potentially curative and palliative surgical interventions.

DISCUSSION

Epilepsy surgery procedure volumes are influenced by US epilepsy center region and other characteristics. These variations may affect access to specific surgical treatments for persons with drug resistant epilepsy across the United States.

The efficacy of laser interstitial thermal therapy in the management of spinal metastases: a systematic review of the literature

BACKGROUND

In the last years, laser interstitial thermal therapy (LITT) has started to be used also in neurosurgical setting. Its efficacy for intracranial pathologies, namely, tumors and epilepsy, has been widely demonstrated. However, the literature evidences about the use of LITT for spinal lesions are recent, and it is still a topic of discussion regarding its efficacy. Here, the authors sought to present a systematic review of the literature investigating the utility of LITT for spinal lesions.

METHODS

Using PubMed, Scopus, and the Cochrane Library, the authors performed a systematic review of the literature focused on the use of spinal laser interstitial thermal therapy (sLITT). Included in the search were randomized controlled trials, cohort studies, and clinical series. Two independent reviewers conducted the study appraisal, data abstraction, and quality assessments of the studies.

RESULTS

Out of the initial 134 studies, 6 met the inclusion criteria for the systematic review, resulting in a total of 206 patients. All the patients have been treated with sLITT for compressive spinal metastases. Most of the lesions were thoracic (88.8%). All the studies reported an effective local control of the disease with a reduction of epidural compression at 30 days. Complication rate was 12.6%, but most of them were transient conditions, and only 3.4% patients needed a revision surgery.

CONCLUSION

sLITT is safe and provides effective local control for epidural compression from metastases, particularly in the thoracic spine. The authors propose considering sLITT as an alternative to open surgery in selected patients with spinal metastases.

Resting-State fMRI Can Detect Alterations in Seizure Onset and Spread Regions in Patients with Non-Lesional Epilepsy: A Pilot Study

Introduction

Epilepsy is defined as non-lesional (NLE) when a lesion cannot be localized via standard neuroimaging. NLE is known to have a poor response to surgery. Stereotactic electroencephalography (sEEG) can detect functional connectivity (FC) between zones of seizure onset (OZ) and early (ESZ) and late (LSZ) spread. We examined whether resting-state fMRI (rsfMRI) can detect FC alterations in NLE to see whether noninvasive imaging techniques can localize areas of seizure propagation to potentially target for intervention.

Methods

This is a retrospective study of 8 patients with refractory NLE who underwent sEEG electrode implantation and 10 controls. The OZ, ESZ, and LSZ were identified by generating regions around sEEG contacts that recorded seizure activity. Amplitude synchronization analysis was used to detect the correlation of the OZ to the ESZ. This was also done using the OZ and ESZ of each NLE patient for each control. Patients with NLE were compared to controls individually using Wilcoxon tests and as a group using Mann-Whitney tests. Amplitude of low-frequency fluctuations (ALFF), fractional ALFF (fALFF), regional homogeneity (ReHo), degree of centrality (DoC), and voxel-mirrored homotopic connectivity (VMHC) were calculated as the difference between NLE and controls and compared between the OZ and ESZ and to zero. A general linear model was used with age as a covariate with Bonferroni correction for multiple comparisons.

Results

Five out of 8 patients with NLE showed decreased correlations from the OZ to the ESZ. Group analysis showed patients with NLE had lower connectivity with the ESZ. Patients with NLE showed higher fALFF and ReHo in the OZ but not the ESZ, and higher DoC in the OZ and ESZ. Our results indicate that patients with NLE show high levels of activity but dysfunctional connections in seizure-related areas.

Discussion

rsfMRI analysis showed decreased connectivity directly between seizure-related areas, while FC metric analysis revealed increases in local and global connectivity in seizure-related areas. FC analysis of rsfMRI can detect functional disruption that may expose the pathophysiology underlying NLE.

Transcranial low-intensity ultrasound stimulation for treating central nervous system disorders: A promising therapeutic application

Transcranial ultrasound stimulation is a neurostimulation technique that has gradually attracted the attention of researchers, especially as a potential therapy for neurological disorders, because of its high spatial resolution, its good penetration depth, and its non-invasiveness. Ultrasound can be categorized as high-intensity and low-intensity based on the intensity of its acoustic wave. High-intensity ultrasound can be used for thermal ablation by taking advantage of its high-energy characteristics. Low-intensity ultrasound, which produces low energy, can be used as a means to regulate the nervous system. The present review describes the current status of research on low-intensity transcranial ultrasound stimulation (LITUS) in the treatment of neurological disorders, such as epilepsy, essential tremor, depression, Parkinson's disease (PD), and Alzheimer's disease (AD). This review summarizes preclinical and clinical studies using LITUS to treat the aforementioned neurological disorders and discusses their underlying mechanisms.

Corpus Callosotomy Is a Safe and Effective Procedure for Medically Resistant Epilepsy

Corpus callosotomy (CC) is an effective surgical treatment for medically resistant generalized or multifocal epilepsy (MRE). The premise of CC extrapolates from the observation that the corpus callosum is the predominant commissural pathway that allows spread and synchroneity of epileptogenic activity between the hemispheres. Candidacy for CC is typically reserved for patients seeking palliative epilepsy treatment with the goal of reducing the frequency of drop attacks, although reduction of other seizure semiologies (absence, complex partial seizures, and tonic-clonic) has been observed. A reduction in morbidity affiliated with evolution of surgical techniques to perform CC has improved the safety profile of the procedure without necessarily sacrificing efficacy.

Vascular and neuronal effects of general anesthesia on the brain: An fMRI study

BACKGROUND AND PURPOSE

A number of functional magnetic resonance imaging (fMRI) studies rely on application of anesthetic agents during scanning that can modulate and complicate interpretation of the measured hemodynamic blood oxygenation level-dependent (BOLD) response. The purpose of the present study was to investigate the effect of general anesthesia on two main components of BOLD signal including neuronal activity and vascular response.

METHODS

Breath-holding (BH) fMRI was conducted in wakefulness and under anesthesia states in 9 patients with drug-resistant epilepsy who needed to get scanned under anesthesia during laser interstitial thermal therapy. BOLD and BOLD cerebrovascular reactivity (BOLD-CVR) maps were compared using t-test between two states to assess the effect of anesthesia on neuronal activity and vascular factors (p < .05).

RESULTS

Overall, our findings revealed an increase in BOLD-CVR and decrease in BOLD response under anesthesia in several brain regions. The results proposed that the modulatory mechanism of anesthetics on neuronal and vascular components of BOLD signal may work in different ways.

CONCLUSION

This experiment for the first human study showed that anesthesia may play an important role in dissociation between neuronal and vascular responses contributed to hemodynamic BOLD signal using BH fMRI imaging that may assist the implication of general anesthesia and interpretation of outcomes in clinical setting.

Exoscope improves visualization and extent of hippocampal resection in temporal lobectomy

INTRODUCTION

Anterior temporal lobectomy (ATL) is a safe and well-validated procedure in the treatment of temporal lobe epilepsy (TLE), but is a challenging technique to master and still confers a risk of morbidity and mortality due to the complex anatomy of the mesial temporal lobe structures. Automated robotic 3D exoscopes have been developed to address limitations traditionally associated with microscopic visualization, allowing for ergonomic, high-definition 3D visualization with hands-free control of the robot. Given the potential advantages of using such a system for visualization of complex anatomy seen during mesial structure resection in ATL, this group sought to investigate impact on the percentage of hippocampal resection in both exoscope and microscope guided procedures.

METHODS

We conducted a retrospective analysis of 20 consecutive patients undergoing standard ATL for treatment of medically refractory TLE at our institution. Using pre-operative and post-operative imaging, the coronal plane cuts in which either the head, body, or tail of the hippocampus appeared were counted. The number of cuts in which the hippocampus appeared were multiplied by slice thickness to estimate hippocampal length.

RESULTS

Mean percentage of hippocampal resection was 61.1 (SD 13.1) and 76.5 (SD 6.5) for microscope and exoscope visualization, respectively (p = 0.0037).

CONCLUSION

Use of exoscope for mesial resection during ATL has provided good visualization for those in the operating room and the potential for a safe increase in hippocampal resection in our series. Further investigation of its applications should be evaluated to see if it will improve outcomes.

Completion of disconnective surgery for refractory epilepsy in pediatric patients using robot-assisted MRI-guided laser interstitial thermal therapy

OBJECTIVE

Since 2007, the authors have performed 34 hemispherotomies and 17 posterior quadrant disconnections (temporoparietooccipital [TPO] disconnections) for refractory epilepsy at Sant Joan de Déu Barcelona Children's Hospital. Incomplete disconnection is the main cause of surgical failure in disconnective surgery, and reoperation is the treatment of choice. In this study, 6 patients previously treated with hemispherotomy required reoperation through open surgery. After the authors' initial experience with real-time MRI-guided laser interstitial thermal therapy (MRIgLITT) for hypothalamic hamartomas, they decided to use this technique instead of open surgery to complete disconnective surgeries. The objective was to report the feasibility, safety, and efficacy of MRIgLITT to complete hemispherotomies and TPO disconnections for refractory epilepsy in pediatric patients.

METHODS

Eight procedures were performed on 6 patients with drug-resistant epilepsy. Patient ages ranged between 4 and 18 years (mean 10 ± 4.4 years). The patients had previously undergone hemispherotomy (4 patients) and TPO disconnection (2 patients) at the hospital. The Visualase system assisted by a Neuromate robotic arm was used. The ablation trajectory was planned along the residual connection. The demographic and epilepsy characteristics of the patients, precision of the robot, details of the laser ablation, complications, and results were prospectively collected.

RESULTS

Four patients underwent hemispherotomy and 2 underwent TPO disconnection. Two patients, including 1 who underwent hemispherotomy and 1 who underwent TPO disconnection, received a second laser ablation because of persistent seizures and connections after the first treatment. The average precision of the system (target point localization error) was 1.7 ± 1.4 mm. The average power used was 6.58 ± 1.53 J. No complications were noted. Currently, 5 of the 6 patients are seizure free (Engel class I) after a mean follow-up of 20.2 ± 5.6 months.

CONCLUSIONS

According to this preliminary experience, laser ablation is a safe method for complete disconnective surgeries and allowed epilepsy control in 5 of the 6 patients treated. A larger sample size and longer follow-up periods are necessary to better assess the efficacy of MRIgLITT to complete hemispherotomy and TPO disconnection, but the initial results are encouraging.

Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for Management of Low-Grade Gliomas and Radiation Necrosis: A Single-Institution Case Series

BACKGROUND

Laser interstitial thermal therapy (LITT) has emerged as a minimally invasive treatment modality for ablation of low-grade glioma (LGG) and radiation necrosis (RN).

OBJECTIVE

To evaluate the efficacy, safety, and survival outcomes of patients with radiographically presumed recurrent or newly diagnosed LGG and RN treated with LITT.

METHODS

The neuro-oncological database of a quaternary center was reviewed for all patients who underwent LITT for management of LGG between 1 January 2013 and 31 December 2020. Clinical data including demographics, lesion characteristics, and clinical and radiographic outcomes were collected. Kaplan-Meier analyses comprised overall survival (OS) and progression-free survival (PFS).

RESULTS

Nine patients (7 men, 2 women; mean [SD] age 50 [16] years) were included. Patients underwent LITT at a mean (SD) of 11.6 (8.5) years after diagnosis. Two (22%) patients had new lesions on radiographic imaging without prior treatment. In the other 7 patients, all (78%) had surgical resection, 6 (67%) had intensity-modulated radiation therapy and chemotherapy, respectively, and 4 (44%) had stereotactic radiosurgery. Two (22%) patients had lesions that were wild-type IDH1 status. Volumetric assessment of preoperative T1-weighted contrast-enhancing and T2-weighted fluid-attenuated inversion recovery (FLAIR) sequences yielded mean (SD) lesion volumes of 4.1 (6.5) cm³ and 26.7 (27.9) cm³, respectively. Three (33%) patients had evidence of radiographic progression after LITT. The pooled median (IQR) PFS for the cohort was 52 (56) months, median (IQR) OS after diagnosis was 183 (72) months, and median (IQR) OS after LITT was 52 (60) months. At the time of the study, 2 (22%) patients were deceased.

CONCLUSIONS

LITT is a safe and effective treatment option for management of LGG and RN, however, there may be increased risk of permanent complications with treatment of deep-seated subcortical lesions.

Minimally invasive surgical techniques in patients with intractable epilepsy with CT-guided stereotactic cryoablation as a superior alternative: a systematic review

Background

Stereotactic cryoablation is a minimally invasive surgical technique that has been used to treat disorders of the brain in the past; however, in current practice, it is primarily used for the treatment of liver, kidney, lung, prostate, and breast neoplasms. In this paper, currently used surgical methods to treat medically refractory seizure disorder are reviewed, and a case is made for the use of stereotactic cryoablation.

Main body

Anterior temporal lobectomy is the gold standard for temporal. There are also several variations of this procedure. Since this is a resective surgery, it can result in neurological defects. To obviate this problem, minimally invasive surgical techniques such as radio frequency ablation and laser interstitial thermal therapy are currently being used for intracranial targets. Cryoablation offers certain advantages over thermal ablations. Cryoablation studies in brain, renal, breast, and other neoplasms have shown that cryoablation has superior abilities to monitor the ablation zone in real time via computerized tomography imaging and also has the capability to create lesions of both smaller and larger sizes. This allows for safer and more effective tumor destruction.

Short conclusion

Based on the review, the authors conclude that further investigation of the use of stereotactic cryoablation in patients with medically intractable epilepsy is needed.

Decision-making in stereotactic epilepsy surgery

Surgery can cure or significantly improve both the frequency and the intensity of seizures in patients with medication-refractory epilepsy. The set of diagnostic and therapeutic interventions involved in the path from initial consultation to definitive surgery is complex and includes a multidisciplinary team of neurologists, neurosurgeons, neuroradiologists, and neuropsychologists, supported by a very large epilepsy-dedicated clinical architecture. In recent years, new practices and technologies have emerged that dramatically expand the scope of interventions performed. Stereoelectroencephalography has become widely adopted for seizure localization; stereotactic laser ablation has enabled more focal, less invasive, and less destructive interventions; and new brain stimulation devices have unlocked treatment of eloquent foci and multifocal onset etiologies. This article articulates and illustrates the full framework for how epilepsy patients are considered for surgical intervention, with particular attention given to stereotactic approaches.

Mapping hippocampal glutamate in mesial temporal lobe epilepsy with glutamate weighted CEST (GluCEST) imaging

Temporal lobe epilepsy (TLE) is one of the most common subtypes of focal epilepsy, with mesial temporal sclerosis (MTS) being a common radiological and histopathological finding. Accurate identification of MTS during presurgical evaluation confers an increased chance of good surgical outcome. Here we propose the use of glutamate-weighted chemical exchange saturation transfer (GluCEST) magnetic resonance imaging (MRI) at 7 Tesla for mapping hippocampal glutamate distribution in epilepsy, allowing to differentiate lesional from non-lesional mesial TLE. We demonstrate that a directional asymmetry index, which quantifies the relative difference between GluCEST contrast in hippocampi ipsilateral and contralateral to the seizure onset zone, can differentiate between sclerotic and non-sclerotic hippocampi, even in instances where traditional presurgical MRI assessments did not provide evidence of sclerosis. Overall, our results suggest that hippocampal glutamate mapping through GluCEST imaging is a valuable addition to the presurgical epilepsy evaluation toolbox.

Volume-Based Radiofrequency Thermocoagulation for Pediatric Insulo-Opercular Epilepsy: A Feasibility Study

BACKGROUND

Stereotactic ablation surgeries including radiofrequency thermocoagulation (RFTC) and laser interstitial thermal therapy are recent less invasive treatment methods for insular epilepsy. Volume-based RFTC after stereoelectroencephalography was first proposed by a French group as a more effective method for seizure relief in insular epilepsy patients than stereoelectroencephalography-guided RFTC.

OBJECTIVE

To describe the feasibility and technical details about volume-based RFTC in patients with insulo-opercular epilepsy.

METHODS

We successfully treated 3- and 6-year-old patients with medically refractory insulo-opercular epilepsy with volume-based RFTC, in which the target volume of coagulation was flexibly designed by combining multiple spherical models of 5-mm diameter which is smaller than reported previously.

RESULTS

The insula was targeted by oblique trajectory from the frontoparietal area in one case, and the opercular cortex was targeted by perpendicular trajectories from the perisylvian cortex in the other case. The use of the small sphere model required more trajectories and manipulations but enabled more exhaustive coagulation of the epileptogenic zone, with 70% to 78% of the planned target volume coagulated without complications, and daily seizures disappeared after RFTC in both patients.

CONCLUSION

Volume-based RFTC planned with small multiple sphere models may improve the completeness of lesioning for patients with insulo-opercular epilepsy. Careful planning is necessary to reduce the risks of vascular injuries.

Robot-Assisted Radiofrequency Ablation Combined with Thermodynamic Simulation for Epilepsy Reoperations

Repeat craniotomies to treat recurrent seizures may be difficult, and minimally invasive radiofrequency ablation is an alternative therapy. On the basis of this procedure, we aimed to develop a more reliable methodology which is helpful for institutions where real-time image monitoring or electrophysiologic guidance during ablation are not available. We used simulation combined with a robot-assisted radiofrequency ablation (S-RARFA) protocol to plan and execute brain epileptic tissue lesioning. Trajectories of electrodes were planned on the robot system, and time-dependent thermodynamics was simulated with radiofrequency parameters. Thermal gradient and margin were displayed on a computer to calculate ablation volume with a mathematic equation. Actual volume was measured on images after the ablation. This small series included one pediatric and two adult patients. The remnant hippocampus, corpus callosum, and irritative zone around arteriovenous malformation nidus were all treated with S-RARFA. The mean error percentage of the volume ablated between preoperative simulation and postoperative measurement was 2.4 ± 0.7%. No complications or newly developed neurologic deficits presented postoperatively, and the patients had little postoperative pain and short hospital stays. In this pilot study, we preliminarily verified the feasibility and safety of this novel protocol. As an alternative to traditional surgeries or real-time monitoring, S-RARFA served as successful seizure reoperation with high accuracy, minimal collateral damage, and good seizure control.

Association of intraoperative end-tidal carbon dioxide level with ablation volume during magnetic resonance-guided laser interstitial thermal therapy for mesial temporal lobe epilepsy

OBJECTIVE

Maximal safe ablation of target structures during magnetic resonance-guided laser interstitial thermal therapy (MRgLiTT) is critical to achieving good seizure outcome in patients with mesial temporal lobe epilepsy (mTLE). The authors sought to determine whether intraoperative physiological variables are associated with ablation volume during MRgLiTT.

METHODS

Patients with mTLE who underwent MRgLiTT at our institution from 2014 to 2019 were retrospectively analyzed. Ablation volume was determined with volumetric analysis of intraoperative postablation MR images. Physiological parameters (systolic blood pressure [SBP], diastolic blood pressure [DBP], mean arterial pressure [MAP], end-tidal carbon dioxide [ETCO2]) measured 40 minutes prior to ablation were analyzed. Univariate and multivariate regression analyses were performed to determine independent predictors of ablation volume.

RESULTS

Forty-four patients met the inclusion criteria. The median (interquartile range) ablation volume was 4.27 (2.92-5.89) cm3, and median ablation energy was 7216 (6402-8784) J. The median MAP, SBP, DBP, and ETCO2 values measured during the 40-minute period leading up to ablation were 72.8 (66.2-81.5) mm Hg, 104.4 (96.4-114.4) mm Hg, 62.4 (54.1-69.8) mm Hg, and 34.1 (32.0-36.2) mm Hg, respectively. In univariate analysis, only total laser energy (r = 0.464, p = 0.003) and 40-minute average ETCO2 (r = -0.388, p = 0.012) were significantly associated with ablation volume. In multivariate analysis, only ETCO2 ≤ 33 mm Hg (p = 0.001) was significantly associated with ablation volume.

CONCLUSIONS

Total ablation energy and ETCO2, but not blood pressure, may significantly affect ablation volume in mTLE patients undergoing MRgLiTT. Mild hypocapnia was associated with increased extent of ablation. Intraoperative monitoring and modulation of ETCO2 may help improve extent of ablation, prediction of ablation volume, and potentially seizure outcome.

Noninvasive disconnection of targeted neuronal circuitry sparing axons of passage and nonneuronal cells

OBJECTIVE

Surgery can be highly effective for the treatment of medically intractable, neurological disorders, such as drug-resistant focal epilepsy. However, despite its benefits, surgery remains substantially underutilized due to both surgical concerns and nonsurgical impediments. In this work, the authors characterized a noninvasive, nonablative strategy to focally destroy neurons in the brain parenchyma with the goal of limiting collateral damage to nontarget structures, such as axons of passage.

METHODS

Low-intensity MR-guided focused ultrasound (MRgFUS), together with intravenous microbubbles, was used to open the blood-brain barrier (BBB) in a transient and focal manner in rats. The period of BBB opening was exploited to focally deliver to the brain parenchyma a systemically administered neurotoxin (quinolinic acid) that is well tolerated peripherally and otherwise impermeable to the BBB.

RESULTS

Focal neuronal loss was observed in targeted areas of BBB opening, including brain regions that are prime objectives for epilepsy surgery. Notably, other structures in the area of neuronal loss, including axons of passage, glial cells, vasculature, and the ventricular wall, were spared with this procedure.

CONCLUSIONS

These findings identify a noninvasive, nonablative approach capable of disconnecting neural circuitry while limiting the neuropathological consequences that attend other surgical procedures. Moreover, this strategy allows conformal targeting, which could enhance the precision and expand the treatment envelope for treating irregularly shaped surgical objectives located in difficult-to-reach sites. Finally, if this strategy translates to the clinic, the noninvasive nature and specificity of the procedure could positively influence both physician referrals for and patient confidence in surgery for medically intractable neurological disorders.

Technical challenges to anterior temporal lobectomy after laser interstitial thermal therapy for mesial temporal lobe epilepsy: technical note

Mesial temporal sclerosis (MTS) is a frequent cause of medically refractory epilepsy, for which laser interstitial thermal therapy (LITT) is an effective treatment. However, experience with the technical considerations posed by additional surgery after an initial LITT procedure is lacking. The authors present the case of a 12-year-old female with medically refractory temporal lobe epilepsy and left MTS who underwent LITT at a separate institution prior to referral. This patient had no change in early postoperative seizure control (Engel class IVB) and then her seizures worsened despite ongoing medical treatment (Engel class IVC). Post-LITT MRI revealed sparing of the mesial hippocampus head, a poor prognostic factor. The authors describe the technical details illustrated by this case of secondary, stereotactic electroencephalography-guided mesial temporal resection following LITT. The case was managed with anterior temporal lobectomy including the resection of residual hippocampus and amygdala.