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.

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.

Recovery of glymphatic system function in patients with temporal lobe epilepsy after surgery.

OBJECTIVES: To investigate the recovery of human glymphatic system (GS) function in patients with temporal lobe epilepsy (TLE) after successful anterior temporal lobectomy (ATL) using diffusion tensor image analysis along the perivascular space (DTI-ALPS). METHODS: We retrospectively analysed DTI-ALPS index in 13 patients with unilateral TLE before and after ATL, and compared the index with 20 healthy controls (HCs). Two-sample t tests and paired t tests were performed to analyse differences in the DTI-ALPS index between patients and HCs. The Pearson correlation analysis was used to observe the relationship between the disease duration and GS function. RESULTS: The DTI-ALPS index before ATL was significantly lower in the hemisphere ipsilateral to the epileptogenic foci than in the contralateral hemisphere of the patients (p < 0.001, t = - 4.81) and in the ipsilateral hemisphere of the HCs (p = 0.007, t = - 2.90). A significant increase in the DTI-ALPS index was found in the hemisphere ipsilateral to the epileptogenic foci after successful ATL (p = 0.01, t = - 3.01). In addition, the DTI-ALPS index of the lesion side before ATL was significantly correlated with disease duration (p = 0.04, r = - 0.59). CONCLUSIONS: DTI-ALPS may be used as a quantitative biomarker evaluating surgical outcomes and TLE disease duration. DTI-ALPS index may also help localise epileptogenic foci in unilateral TLE. Overall, our study suggests that GS may potentially serve as a new method for the management of TLE and a new direction for investigating the mechanism of epilepsy. KEY POINTS: • DTI-ALPS index may contribute to epileptogenic foci lateralisation in TLE. • DTI-ALPS index is a potential quantitative feature evaluating surgical outcomes and TLE disease duration. • The GS provides a new perspective for the study of TLE.

Drug-resistant temporal lobe epilepsy with temporal encephaloceles: How far to resect.

PURPOSE: This study sought to evaluate the impact of surgical extent on seizure outcome in drug-resistant temporal lobe epilepsy (DR-TLE) with temporal encephaloceles (TE). METHODS: This was a single-institution retrospective study of patients who underwent surgery for DR-TLE with TE between January 2008 and December 2020. The impact of surgical extent on seizure outcome was evaluated. In a subset with dominant DR-TLE, the impact of surgical extent on neuropsychometric outcome was evaluated. RESULTS: Thirty-four patients were identified (female, 56%; median age at surgery, 43 years). TE were frequently overlooked on initial magnetic resonance imaging (MRI), with encephaloceles only detected after repeat or expert re-review of MRI, additional multi-modal imaging, or intra-operatively in 31 (91%). Sixteen (47%) underwent limited resections, including encephalocele resection only (n = 5) and encephalocele resection with more extensive temporal corticectomy sparing the amygdala and hippocampus (n = 11). The remainder (n = 18, 53%) underwent standard anterior temporal lobectomy and amygdalohippocampectomy (ATLAH). Limited resection was performed more frequently on the left (12/17 vs. 4/17, p = 0.015). Twenty-seven patients (79%) had a favourable outcome (Engel I/II), and 17 (50%) were seizure-free at the last follow-up (median seizure-free survival of 27.3 months). There was no statistically significant difference in seizure-free outcomes between limited resection and ATLAH. In dominant DR-TLE, verbal memory decline was more likely after ATLAH than limited resection (3/4 vs. 0/9, p = 0.014). CONCLUSION: Expert re-review of imaging and multi-modal advanced imaging improved TE identification. There was no statistical difference in seizure-free outcomes based on surgical extent. Preservation of verbal memory supports limited resection in dominant temporal cases.

Avoidance of Pitfalls and Complications During Surgery for Temporal Lobe Epilepsy.

Anterior temporal lobectomy with amygdalohippocampectomy is the most common epilepsy surgery, which, in cases of mesial temporal lobe epilepsy caused by mesial temporal sclerosis, usually leads to improvements in seizure control, cognitive function, and quality of life. Nevertheless, while the primary goal of intervention is achieved in a large majority of patients, a small number of them, unfortunately, encounter complications. Some morbidity is nonspecific and may be noted after any craniotomy (e.g., surgical site infections, meningitis, bone flap osteomyelitis, and operative site or craniotomy-related hematomas). On the other hand, certain complications are specifically associated with surgery for temporal lobe epilepsy and can be discussed from the etiological standpoint: mechanical injuries of the brain; injury of eloquent neuronal structures; arterial and venous injuries; cerebral venous thrombosis; remote cerebellar hemorrhage; and postoperative hydrocephalus, seizures, and psychiatric disorders. In many cases, these complications are manifested in the early postoperative period by alterations of consciousness and a focal neurological deficit, and it may require immediate decisions on their appropriate management.

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.

3D4K exoscope in epilepsy surgery: a seminal experience.

BACKGROUND AND OBJECTIVES: To report the progressive introduction of the exoscope (EX) from surface lesionectomy to antero-mesial temporal lobectomy (AMTL) in an epilepsy surgery practice. METHODS: We describe a population of ten consecutive patients undergoing EX surgery, with a minimum follow-up of 6 months, that was compared to a similar population of patients referred to operative microscopic surgery (OM). RESULTS: All surgeries were performed with the use of EX or OM alone. Transient neurological complications for surgery in eloquent regions were recorded in one patient for each population. Nine and seven patients undergoing, respectively, EX and OM surgery resulted in Engel class Ia (90% vs. 70%). The mean duration of EX and OM surgery resulted in 265.5 and 237.9 min, respectively, with a mean of 308.3 and 253.3 min for AMTL cases, respectively. CONCLUSIONS: This preliminary study revealed that ORBEYE EX can be safe and effective in different types of epilepsy surgeries. The transition from OM to EX is fast, even though it is slower for the more challenging mesial temporal structure removal. Ergonomic and operative team interaction is improved by the use of EX. Our data need to be confirmed by larger studies.

Quantitative analysis of visually reviewed normal scalp EEG predicts seizure freedom following anterior temporal lobectomy.

OBJECTIVE: Anterior temporal lobectomy (ATL) is a widely performed and successful intervention for drug-resistant temporal lobe epilepsy (TLE). However, up to one third of patients experience seizure recurrence within 1 year after ATL. Despite the extensive literature on presurgical electroencephalography (EEG) and magnetic resonance imaging (MRI) abnormalities to prognosticate seizure freedom following ATL, the value of quantitative analysis of visually reviewed normal interictal EEG in such prognostication remains unclear. In this retrospective multicenter study, we investigate whether machine learning analysis of normal interictal scalp EEG studies can inform the prediction of postoperative seizure freedom outcomes in patients who have undergone ATL. METHODS: We analyzed normal presurgical scalp EEG recordings from 41 Mayo Clinic (MC) and 23 Cleveland Clinic (CC) patients. We used an unbiased automated algorithm to extract eyes closed awake epochs from scalp EEG studies that were free of any epileptiform activity and then extracted spectral EEG features representing (a) spectral power and (b) interhemispheric spectral coherence in frequencies between 1 and 25 Hz across several brain regions. We analyzed the differences between the seizure-free and non-seizure-free patients and employed a Naïve Bayes classifier using multiple spectral features to predict surgery outcomes. We trained the classifier using a leave-one-patient-out cross-validation scheme within the MC data set and then tested using the out-of-sample CC data set. Finally, we compared the predictive performance of normal scalp EEG-derived features against MRI abnormalities. RESULTS: We found that several spectral power and coherence features showed significant differences correlated with surgical outcomes and that they were most pronounced in the 10-25 Hz range. The Naïve Bayes classification based on those features predicted 1-year seizure freedom following ATL with area under the curve (AUC) values of 0.78 and 0.76 for the MC and CC data sets, respectively. Subsequent analyses revealed that (a) interhemispheric spectral coherence features in the 10-25 Hz range provided better predictability than other combinations and (b) normal scalp EEG-derived features provided superior and potentially distinct predictive value when compared with MRI abnormalities (>10% higher F1 score). SIGNIFICANCE: These results support that quantitative analysis of even a normal presurgical scalp EEG may help prognosticate seizure freedom following ATL in patients with drug-resistant TLE. Although the mechanism for this result is not known, the scalp EEG spectral and coherence properties predicting seizure freedom may represent activity arising from the neocortex or the networks responsible for temporal lobe seizure generation within vs outside the margins of an ATL.

Altered Resting State Networks Before and After Temporal Lobe Epilepsy Surgery.

OBJECTIVES: To explore the resting state networks (RSNs) alterations in patients with unilateral mesial temporal lobe epilepsy (mTLE) before and after successful surgery. METHODS: Resting-state functional MRI and T1-weighted structural MRI were obtained in 37 mTLE patients who achieved seizure freedom after anterior temporal lobectomy. Patients were scanned before surgery and at two years after surgery. Twenty-eight age- and sex-matched healthy controls were scanned once. Functional connectivity (FC) changes within and between ten common RSNs before and after surgery, and FC changes between hippocampus and RSNs were explored. RESULTS: Before surgery, decreased FC was found within visual network and basal ganglia network, while after surgery, FC within basal ganglia network further decreased but FC within sensorimotor network and dorsal attention network increased. Before surgery, between-network FC related to basal ganglia network, visual network and dorsal attention network decreased, while between-network FC related to default mode network increased. After surgery, between-network FC related to visual network and dorsal attention network significantly increased. In addition, before surgery, ipsilateral hippocampus showed decreased FC with visual network, basal ganglia network, sensorimotor network, default mode network and frontoparietal network, while contralateral rostral hippocampus showed increased FC with salience network. After surgery, no obvious FC changes were found between contralateral hippocampus and these RSNs. CONCLUSION: MTLE patients showed significant RSNs alterations before and after surgery. Basal ganglia network showed progressive decline in functional connectivity. Successful surgery may lead to RSNs reorganization. These results provide preliminary evidence for postoperative functional remodeling at whole-brain-network level.

Depression and suicide after temporal lobe epilepsy surgery: A systematic review.

Psychiatric comorbidities, including depression and suicide, contribute substantially to the illness burden of patients with refractory temporal lobe epilepsy (TLE). The aim of this systematic review was to synthesize the existing literature assessing the effect of TLE surgery on (1) depression prevalence and (2) severity, and estimating the incidence of (3) de novo depression and (4) attempted and completed suicide following TLE surgery. A literature search was performed using Ovid Medline, Embase, Clarivate Web of Science, Cochrane Library, and ProQuest Dissertations and Theses. Studies of patients with TLE who underwent TLE surgery and reported estimates of at least one of the following outcomes were included: pre- and postoperative depression prevalence or severity, the incidence of postoperative de novo depression, or attempted or completed suicide. The search yielded 2,127 citations related to TLE surgery and postoperative depression or suicide. After a full-text review of 98 articles, 18 met the final eligibility criteria. Most studies reported a reduced or similar prevalence (n = 12) and severity of depression (n = 5) postoperatively, compared with the preoperative period. Eleven studies reported the incidence of postoperative de novo depression, which ranged from 0 % to 38 % over follow-up periods of three months to nine years. Four studies assessed the incidence of postoperative attempted or completed suicide, with completed suicide incidence ranging from 0 % to 3 % over follow-up periods of one to four years. Overall, the effect of TLE surgery on depression and suicide remains unclear, as many studies did not assess the statistical significance of depression prevalence or severity changes following TLE surgery. Therefore, timely psychosocial follow-up for patients after TLE surgery should be considered. Future longitudinal studies with consistent measures are needed to elucidate the effect of TLE surgery on the prevalence and severity of depression and estimate the incidence of de novo depression and suicide following surgery.

A simulation study to investigate the use of concentric tube robots for epilepsy surgery.

PURPOSE: Patients with pharmacoresistant refractory epilepsy may require epilepsy surgery to prevent future seizure occurrences. Conventional surgery consists of a large craniotomy with straight rigid tools with associated outcomes of morbidity, large tissue resections, and long post-operative recovery times. Concentric tube robots have recently been developed as a promising application to neurosurgery due to their nonlinear form and small diameter. The authors present a concept study to explore the feasibility of performing minimally invasive hemispherotomy with concentric tube robots. METHODS: A model simulation was used to achieve the optimal design and surgical path planning parameters of the concentric tube robot for corpus callosotomy and temporal lobectomy. A single medial burr hole was chosen to access the lateral ventricles for both white matter disconnections. RESULTS: The concentric tube robot was able to accurately reach the designated surgical paths on the corpus callosum and the temporal lobe. CONCLUSION: In a model simulation, the authors demonstrated the feasibility of performing corpus callosotomy and temporal lobectomy using concentric tube robots. Further advancements in the technology may increase the applicability of this technique for epilepsy surgery to better patient outcomes.

Fully automated delineation of the optic radiation for surgical planning using clinically feasible sequences.

Quadrantanopia caused by inadvertent severing of Meyer's Loop of the optic radiation is a well-recognised complication of temporal lobectomy for conditions such as epilepsy. Dissection studies indicate that the anterior extent of Meyer's Loop varies considerably between individuals. Quantifying this for individual patients is thus an important step to improve the safety profile of temporal lobectomies. Previous attempts to delineate Meyer's Loop using diffusion MRI tractography have had difficulty estimating its full anterior extent, required manual ROI placement, and/or relied on advanced diffusion sequences that cannot be acquired routinely in most clinics. Here we present CONSULT: a pipeline that can delineate the optic radiation from raw DICOM data in a completely automated way via a combination of robust pre-processing, segmentation, and alignment stages, plus simple improvements that bolster the efficiency and reliability of standard tractography. We tested CONSULT on 696 scans of predominantly healthy participants (539 unique brains), including both advanced acquisitions and simpler acquisitions that could be acquired in clinically acceptable timeframes. Delineations completed without error in 99.4% of the scans. The distance between Meyer's Loop and the temporal pole closely matched both averages and ranges reported in dissection studies for all tested sequences. Median scan-rescan error of this distance was 1 mm. When tested on two participants with considerable pathology, delineations were successful and realistic. Through this, we demonstrate not only how to identify Meyer's Loop with clinically feasible sequences, but also that this can be achieved without fundamental changes to tractography algorithms or complex post-processing methods.

Low prevalence of amyloid and tau pathology in drug-resistant temporal lobe epilepsy.

OBJECTIVE: Cognitive impairment is common in patients with chronic drug-resistant temporal lobe epilepsy (TLE). Hyperphosphorylated tau (pTau) and amyloid-ß (Aß) plaques, pathological hallmarks of Alzheimer disease, have been hypothesized to play a mechanistic role. We investigated Aß plaques and pTau prevalence in TLE patients who underwent resective surgery and correlated their presence with preoperative psychometric test scores and clinical factors. METHODS: Patients were retrospectively selected from the epilepsy surgery register of the Royal Melbourne Hospital, Australia. Sections from the resected temporal lobe were immunostained for pTau and Aß plaques (antibodies: AT8, 1E8). The presence and severity of pathology were correlated with clinical characteristics, and verbal and visual learning functions as measured by the Verbal Pair Associates (VPA) test and Rey Complex Figure Test. RESULTS: Fifty-six patients (55% female) aged 20-68 years (median = 34 years) at surgery were included. Aß plaques were detected in four patients (7%), all at the moderate level. There was no difference in duration, age at onset of epilepsy, or side of resection between patients with and without Aß plaques. Sparse pTau was found in two patients (3.5%). Both had moderate Aß plaques and were >50 years of age. Patients with Aß plaques had a lower median score for the VPA hard assessment compared to those without (0 vs. 4; p = .02). There was otherwise no correlation between pathology and psychometric test scores. SIGNIFICANCE: Aß plaques and pTau were uncommon in the resected brain tissue of patients who have undergone temporal lobectomy, and did not correlate with clinical characteristics or preoperative psychometric test scores, except for a lower VPA median score in patients with Aß plaques. Therefore, considering the low prevalence of Aß plaques and pTau herein observed, it is unlikely that cognitive impairment in TLE is driven by the same mechanisms as in Alzheimer disease.

Dynamic gray matter and intrinsic activity changes after epilepsy surgery.

OBJECTIVES: To explore the dynamic changes of gray matter volume and intrinsic brain activity following anterior temporal lobectomy (ATL) in patients with unilateral mesial temporal lobe epilepsy (mTLE) who achieved seizure-free for 2 years. MATERIALS AND METHODS: High-resolution T1-weighted MRI and resting-state functional MRI data were obtained in ten mTLE patients at five serial timepoints: before surgery, 3, 6, 12, and 24 months after surgery. The gray matter volume (GMV) and amplitude of low-frequency fluctuations (ALFF) were compared among the five scans to depict the dynamic changes after ATL. RESULTS: After successful ATL, GMV decreased in several ipsilateral brain regions: ipsilateral insula, thalamus, and putamen showed gradual gray matter atrophy from 3 to 24 months, while ipsilateral superior temporal gyrus, middle temporal gyrus, inferior temporal gyrus, middle occipital gyrus, inferior occipital gyrus, caudate nucleus, lingual gyrus, and fusiform gyrus showed significant GMV decrease at 3 months follow-up, without further changes. Ipsilateral insula showed gradual ALFF decrease from 3 to 24 months after surgery. Ipsilateral superior temporal gyrus showed ALFF decrease at 3 months follow-up, without further changes. Ipsilateral thalamus and cerebellar vermis showed obvious ALFF increase after surgery. CONCLUSIONS: Surgical resection may lead to a short-term reduction of gray matter volume and intrinsic brain activity in neighboring regions, while the progressive gray matter atrophy may be due to possible intrinsic mechanism of mTLE. Dynamic ALFF changes provide evidence that disrupted focal spontaneous activities were reorganized after successful surgery.

Recovery of cortical atrophy in patients with temporal lobe epilepsy after successful anterior temporal lobectomy.

The aims of this study were to investigate whether the cortical atrophy caused by temporal lobe epilepsy (TLE) was reversible after successful anterior temporal lobectomy (ATL) and to further observe whether possible changes are related to age at surgery and cognitive changes. Twelve patients with unilateral mesial TLE who received ATL and remained seizure free in one year follow-up were included. They underwent two MRI scans few days before and oneyear after surgery. Thirty age- and sex-matched healthy participants were recruited as controls. Group comparisons were used to test the differences in cortical thickness (CTh) between the pre-/postsurgical patients and controls. Longitudinal test was used to directly show postsurgical changes of the patients. Besides, the correlations between regional cortical volume (CVo) changes and age at surgery or cognitive changes were also tested. Compared with controls, the patients with TLE showed dispersed cortical thinning especially in the bilateral frontal lobes before surgery and no significant cortical thinning except for cortices near the resected areas after surgery. The longitudinal analysis showed CTh increment in the ipsilateral precentral and postcentral gyrus, cuneus and widespread in the contralateral cortex. In the volumetric analysis, the CVo changes in the contralateral hemisphere were negatively correlated with age at surgery and positively correlated with MoCA score changes. This study suggests that the cortical atrophy caused by TLE could recover after successful ATL. The recovery ability is greater in younger subjects and is positively related to cognitive recovery. These findings could serve as new clues that patients with TLE can benefit from timely and successful ATL.

Consequences of mesial temporal sparing temporal lobe surgery in medically refractory epilepsy.

OBJECTIVE: We compared long-term seizure outcome, neuropsychological outcome, and occupational outcome of anterior temporal lobectomy (ATL) with and without sparing of mesial structures to determine whether mesial sparing temporal lobectomy prevents memory decline and thus disability, with acceptable seizure outcome. METHODS: We studied patients (n = 21) and controls (n = 21) with no evidence of mesial temporal sclerosis (MTS) on MRI who had surgery to treat drug-resistant epilepsy. Demographic and pre- and postsurgical clinical characteristics were compared. Patients had neuropsychological assessment before and after surgery. Neuropsychological analyses were limited to patients with left-sided surgery and available data (n = 14 in each group) as they were at risk of verbal memory impairment. The California Verbal Learning Test II (CVLT-II) (sum of trials 1-5, delayed free recall) and the Logical Memory subtest of the Wechsler Memory Scale III or IV (WMS-III or WMS-IV) (learning and delayed recall of prose passages) were used to assess verbal episodic learning and memory. Seizure and occupational outcomes were assessed. RESULTS: The chance of attaining seizure freedom was similar in the two groups, so sparing mesial temporal structures did not lessen the chance of stopping seizures. Sparing mesial temporal structures mitigated the extent of postoperative verbal memory impairment, though some of these individuals suffered decline as a consequence of surgery. Occupational outcome was similar in both groups. SIGNIFICANCE: Mesial temporal sparing resections provide a similar seizure outcome as ATL, while producing a better memory outcome. Anterior temporal lobectomy including mesial structure resection did not increase the risk of postoperative disability.

[Surgical treatment of drug-resistant epilepsy following hippocampal sclerosis]. / Khirurgicheskoe lechenie farmakorezistentnoi epilepsii pri skleroze gippokampa.

Surgery is an effective approach for drug-resistant temporal lobe epilepsy following hippocampal sclerosis. There is still no clear and unanimous opinion about advantages and disadvantages of certain surgical technique. MATERIAL AND METHODS: There were 103 surgical interventions in 101 patients. Females prevailed (1.45:1). Age of patients ranged from 16 to 56 years (median 28). Anteromedial temporal lobectomy and selective amygdaloghippocampectomy were performed in 49 (47.6%) and 54 (52.4%) patients, respectively. In the latter group, 30 patients were operated via a 14-mm burr hole-subtemporal approach. Postoperative outcomes were assessed using the Engel grading system. The follow-up period ranged from 2 to 8 years (median 4 years). RESULTS: By the 2nd year, Engel class I was observed in 74 (72%) patients, Engel II, III and IV - in 20 (19.4%), 6 (5.8%) and 3 (2.9%) patients, respectively. Engel class I was achieved after anteromedial temporal lobectomy in 68% of cases, selective amygdaloghippocampectomy via standard approaches in 75% of cases, amygdaloghippocampectomy via subtemporal burr hole approach - in 80% of cases. Neurocognitive impairments after anteromedial lobectomy and selective amygdaloghippocampectomy were similar. At the same time, mental disorders de novo prevailed in the group of anteromedial lobectomy (p<0.05). There were no severe visual field disorders after subtemporal burr-hole access. In other cases, these disorders occurred in 36.2% of patients (p<0.05). There were 8 (7.8%) postoperative complications: 5 (10.2%) - after anterior temporal lobectomy, 3 (5.5%) - after selective surgeries via standard approaches. There were no complications after burr-hole surgery. CONCLUSION: Selective amygdaloghippocampectomy is not inferior to anteromedial lobectomy. Moreover, this procedure is associated with a lower risk of complications and adverse events.

Anterior temporal encephaloceles: Elusive, important, and rewarding to treat.

OBJECTIVE: To investigate the etiology and longitudinal clinical, neuropsychological, psychosocial, and surgical outcome profile of patients with medication refractory epilepsy and temporal encephaloceles with a view to highlight diagnostic clues and management strategies. METHODS: The comprehensive epilepsy program databases at two surgical epilepsy centers from January 2000 to October 2018 were reviewed for this observational study, to identify patients with encephaloceles causing temporal lobe epilepsy (TLE) and treated with surgical resection. Their clinical, radiological, neuropsychological, psychiatric, and surgical data were obtained. Body mass index (BMI) data were also reviewed due to possible correlation between idiopathic intracranial hypertension and encephaloceles. RESULTS: Thirteen patients (eight female) were identified; only three were recognized on initial magnetic resonance imaging (MRI) report. Temporal encephaloceles were identified on the left in eight patients, on the right in three patients, and bilaterally in two patients. One patient had a strong family history of encephaloceles. The median BMI for patients with seizure onset ≤20 years of age was 22.4, whereas for patients with onset >20 years median BMI was 32.6 (P = .06). Five patients underwent a focal lesionectomy, three patients had limited temporal lobectomy, and five patients had standard anterior temporal lobectomy. Median postoperative follow-up was 5.5 years. All but one patient were free of disabling seizures. Nine of ten neuropsychologically tested patients had no discernable cognitive decline postoperatively. Postoperative psychosocial adjustment features were present in four patients. SIGNIFICANCE: Genetic factors and a possible association with idiopathic intracranial hypertension (given female predominance and elevated BMI) may contribute to the causation of temporal lobe encephaloceles. It is notable that a targeted surgical approach in the management of patients with TLE associated with encephaloceles has an excellent long-term clinical and neuropsychological outcome. Subtle encephaloceles should be actively searched for in patients with drug-resistant TLE because they significantly change surgical strategy and prognostication.

Mesial temporal resection following long-term ambulatory intracranial EEG monitoring with a direct brain-responsive neurostimulation system.

OBJECTIVE: To describe seizure outcomes in patients with medically refractory epilepsy who had evidence of bilateral mesial temporal lobe (MTL) seizure onsets and underwent MTL resection based on chronic ambulatory intracranial EEG (ICEEG) data from a direct brain-responsive neurostimulator (RNS) system. METHODS: We retrospectively identified all patients at 17 epilepsy centers with MTL epilepsy who were treated with the RNS System using bilateral MTL leads, and in whom an MTL resection was subsequently performed. Presumed lateralization based on routine presurgical approaches was compared to lateralization determined by RNS System chronic ambulatory ICEEG recordings. The primary outcome was frequency of disabling seizures at last 3-month follow-up after MTL resection compared to seizure frequency 3 months before MTL resection. RESULTS: We identified 157 patients treated with the RNS System with bilateral MTL leads due to presumed bitemporal epilepsy. Twenty-five patients (16%) subsequently had an MTL resection informed by chronic ambulatory ICEEG (mean = 42 months ICEEG); follow-up was available for 24 patients. After MTL resection, the median reduction in disabling seizures at last follow-up was 100% (mean: 94%; range: 50%-100%). Nine patients (38%) had exclusively unilateral electrographic seizures recorded by chronic ambulatory ICEEG and all were seizure-free at last follow-up after MTL resection; eight of nine continued RNS System treatment. Fifteen patients (62%) had bilateral MTL electrographic seizures, had an MTL resection on the more active side, continued RNS System treatment, and achieved a median clinical seizure reduction of 100% (mean: 90%; range: 50%-100%) at last follow-up, with eight of fifteen seizure-free. For those with more than 1 year of follow-up (N = 21), 15 patients (71%) were seizure-free during the most recent year, including all eight patients with unilateral onsets and 7 of 13 patients (54%) with bilateral onsets. SIGNIFICANCE: Chronic ambulatory ICEEG data provide information about lateralization of MTL seizures and can identify additional patients who may benefit from MTL resection.

Safety metric profiling in surgery for temporal glioblastoma: lobectomy as a supra-total resection regime preserves perioperative standard quality rates.

INTRODUCTION: Supra-total resection in terms of anterior temporal lobectomy (ATL) has gained growing attention with regard to superior long-term disease control for temporal-located glioblastoma. However, aggressive onco-surgical approaches-geared beyond conventional gross total resections (GTR)-may be associated with peri- and postoperative unfavorable events which significantly worsen initial favorable postoperative outcome. In the current study we analyzed our institutional database with regard to patient safety indicators (PSIs), hospital-acquired conditions (HACs) and specific cranial surgery-related complications (CSC) as high standard quality metric profiles in patients that had undergone surgery for temporal glioblastoma. METHODS: Between 2012 and 2018, 61 patients with temporal glioblastoma underwent GTR or temporal lobectomy at the authors' institution. Both groups of differing resection modalities were analyzed with regard to the incidence of PSIs, HACs and CSCs. RESULTS: Overall, we found 6 PSI and 2 HAC events. Postoperative hemorrhage (3 out of 61 patients; 5%) and catheter-associated urinary tract infection (2 out 61 patients; 3%) were identified as the most frequent PSIs and HACs. PSIs were present in 1 out of 41 patients (5%) for the temporal GTR and 2 out of 20 patients for the lobectomy group (p = 1.0). Respective rates for PSIs were 5 of 41 (12%) and 1 of 20 (5%) (p = 0.7). Further, CSCs did not yield significant differences between these two resection modalities (p = 1.0). CONCLUSION: With regard to ATL and GTR as differing onco-surgical approaches these data suggest ATL in terms of an aggressive supra-total resection strategy to preserve perioperative standard safety metric profiles.