Temporal Resection Research Articles

RTHP-30. DOES THE TEMPORAL LOBECTOMY CAVITY NEED TO BE IRRADIATED? PATTERNS OF RECURRENCE AND IMPLICATIONS FOR POSTOPERATIVE RADIATION TREATMENT FIELD DESIGN FOR TEMPORAL LOBE GLIOMAS.

Abstract BACKGROUND Treatment of temporal lobe glioma (TLG) frequently includes partial or complete temporal lobectomy (TL) followed by radiotherapy (RT). However, there are two approaches for temporal resection cavity RT, 1) standard target volumes (STV) targeting the entire TL resection cavity, dura, and peri-tumoral brain parenchyma or 2) modified target volumes (MTV) targeting only the adjacent peri-tumoral brain parenchyma. We report patterns of failure and a dosimetric comparison of these approaches. MATERIALS AND METHODS This was a retrospective review of 49 patients with WHO grade II-IV TLG who underwent partial or complete TL and post-operative RT between 1998 and 2018. Progression-free survival (PFS) was estimated using the Kaplan-Meier method. RESULTS The median patient age was 56 years (range,21–76). Patients were diagnosed with glioblastoma (n=32,65%), anaplastic glioma (n=10,20%) and low-grade glioma (n=7,14%). Treatment included partial TL with STV (n=33,67%), partial TL with MTV (n=5,10%), complete TL with STV (n=8,16%) and complete TL with MTV (n=3,6%). Mean RT dose was 60 Gy (range,40–76) in 30 fractions (range,15–39). At median follow-up time of 18 months (range, 3–161), 44 patients (90%) experienced recurrence: 34 (77%) in-field, 5 (11%) out-of-field, and 5 (11%) both in- and out-of-field. Among the 39 in-field failures, the location of recurrence included brain parenchyma (n=38,97%), ventricle (n=6,15%), and dura (n=5,13%). No patient experienced isolated dural recurrence regardless of tumor grade, extent of TL, or radiation volume. Median PFS was 20 months (95% confidence interval [CI]: 15–24). RT volume (STV vs. MTV) was not associated with worsened PFS (hazard ratio: 1.1, 95% CI: 0.5–2.6). MTV was associated with significant reductions in mean or max doses to brain stem, optic chiasm, optic nerves, hippocampus, and pituitary compared to STV. CONCLUSION Omitting RT to the entire TL cavity may reduce dose to multiple normal tissues with no detriments in dural recurrence or PFS.

Extracranial Metastasis of an Anaplastic Ependymoma, RELA Fusion-Positive: A Rare Occurrence

Primary intracranial ependymomas originate from ependymal cells. They may migrate mainly in the spinal cord but rarely metastasize outside the central nervous system. Metastases outside the central nervous system are rare. Metastatic diffusion from the central nervous system is low due to the unique interaction of the brain and the tumor with the blood-brain barrier. Nevertheless, three main hypotheses have been mentioned in the literature, the tumor growth, the surgical manipulation (which may be considered to be the case in our patient), and the aggressiveness of the tumor according to the Ki67 index. We report the case of a 16-year-old female, who underwent complete surgical removal of a left occipital 2007 WHO grade II ependymoma. 3 years later, the patient presented multiple cervical and occipital indurated masses. MRI showed a left hemispheric meningeal infiltration, with multiple nodules located on the neck, occiput and mastoid. Histopathological study of a left temporal surgical biopsy and resection of an occipital subcutaneous nodule turned to be metastases of an anaplastic ependymoma. The ependymoma considered as a benign tumor could very quickly turn into malignancy by its metastatic potential. Early diagnosis and longer follow-up of patients would be recommended for a rapid management.

Regional Connectivity Changes According to Seizure Outcome of Temporal Epilepsy Surgery: A Magnetoencephalography Study

For patients with medically intractable temporal lobe epilepsy (TLE), anterior temporal resection has been mostly frequent treatment...

Decision-making in temporal lobe epilepsy surgery based on invasive stereo-electroencephalography (sEEG).

In medical refractory temporal lobe epilepsy (TLE), the epileptogenic zone can be difficult to identify and therefore difficult to treat, especially in the absence of clear MRI pathologies and specific results from presurgical evaluation. Invasive monitoring with stereo-electroencephalography (sEEG) is a tool for a better determination of the epileptogenic zone. Here, we investigate the impact of sEEG on decision-making in temporal lobe epilepsy surgery. We reviewed patients with TLE who underwent further investigation with sEEG in our epilepsy unit. We examined specifically how sEEG findings influenced our decision regarding indication for a surgical procedure and resection volume. From 2013 to 2017, we performed 152 temporal resections in epilepsy patients. Twenty-one of these patients were designated for further preoperative investigation with sEEG due to incongruent findings in presurgical evaluation. Six patients were implanted bitemporally. In five cases, the hypothesis for the epileptogenic zone and localization had to be changed due to sEEG findings and resulted in a different tailored resection than intended. In three cases, sEEG findings led to the cancelation of the originally intended temporal resection as the epileptogenic zone was not definable or bilateral. In another three cases, the prognosis for reduction of seizures postoperatively had to be reduced due to the sEEG findings. However, the resection was performed after interdisciplinary discussion and informed consent of the patient. The examination by sEEG led to a change of plan for further treatment in 13 patients (61.9%) suffering TLE in total. Invasive monitoring with sEEG electrodes had a strong impact on decision-making for further treatment in patients suffering from temporal lobe epilepsy with incongruent findings in presurgical examination designated for epilepsy surgery. This applies to resection volumes as well as to prediction of seizure outcome.

Are low-grade gliomas of mesial temporal area alone?

Background:Temporal neocortex which appears normal on magnetic resonance imaging (MRI) may have pathological tissues in low-grade gliomas (LGG) of pure mesial temporal area. Resection of the cortex may be required together with mesial temporal glioma for satisfactory seizure and oncological outcome. The aim of this study was to explore the presence of any pathological tissue on the temporal cortex that appeared normal on preoperative MRI in patients with pure mesial temporal LGGs.Methods:This prospective study included 10 patients who underwent surgical resection of temporal lobe for LGG of mesial temporal area. The temporal neocortex with normal appearance on MRI and mesial temporal area were resected separately, and histopathological diagnosis was performed.Results:LGGs of the mesial temporal area were diagnosed with glioneuronal tumors in 7 (70%) and low-grade astrocytoma in 2 (20%) patients. Regarding the temporal cortex, gliosis and focal cortical dysplasia were found in 7 (70%) and 2 (20%) patients. In one patient temporal cortex did not contain any pathological tissue. All were seizure-free and no tumor recurrence was noted at the last follow-up.Conclusion:Mesial temporal LGGs are not alone and a high proportion of temporal neocortex appeared normal on preoperative MRI, may contain dual pathology. Thus, anterior temporal resection should be performed to have satisfactory seizure and oncological outcomes.

Multicenter validation of automated trajectories for selective laser amygdalohippocampectomy.

ObjectiveLaser interstitial thermal therapy (LITT) is a novel minimally invasive alternative to open mesial temporal resection in drug‐resistant mesial temporal lobe epilepsy (MTLE). The safety and efficacy of the procedure are dependent on the preplanned trajectory and the extent of the planned ablation achieved. Ablation of the mesial hippocampal head has been suggested to be an independent predictor of seizure freedom, whereas sparing of collateral structures is thought to result in improved neuropsychological outcomes. We aim to validate an automated trajectory planning platform against manually planned trajectories to objectively standardize the process.MethodsUsing the EpiNav platform, we compare automated trajectory planning parameters derived from expert opinion and machine learning to undertake a multicenter validation against manually planned and implemented trajectories in 95 patients with MTLE. We estimate ablation volumes of regions of interest and quantify the size of the avascular corridor through the use of a risk score as a marker of safety. We also undertake blinded external expert feasibility and preference ratings.ResultsAutomated trajectory planning employs complex algorithms to maximize ablation of the mesial hippocampal head and amygdala, while sparing the parahippocampal gyrus. Automated trajectories resulted in significantly lower calculated risk scores and greater amygdala ablation percentage, whereas overall hippocampal ablation percentage did not differ significantly. In addition, estimated damage to collateral structures was reduced. Blinded external expert raters were significantly more likely to prefer automated to manually planned trajectories.SignificanceRetrospective studies of automated trajectory planning show much promise in improving safety parameters and ablation volumes during LITT for MTLE. Multicenter validation provides evidence that the algorithm is robust, and blinded external expert ratings indicate that the trajectories are clinically feasible. Prospective validation studies are now required to determine if automated trajectories translate into improved seizure freedom rates and reduced neuropsychological deficits.

A-41 Verbal Fluency and Switching Accuracy Differences in Pediatric Epilepsy Pre- and Post- Surgery

Abstract Objective In patients with epilepsy, research is variable with regard to language difficulties. Previous research generally focuses on phonemic and semantic verbal fluency in pediatric populations post-surgery; however, few studies examine category switching accuracy. This study compared phonemic fluency, categorical fluency, switching accuracy, and the number of switches among pre-surgical and post-surgical groups. Methods Participants included 31 epilepsy patients (age 5-20 years old; M = 12.23 years pre-surgery; M = 14.72 years post-surgery; 20 males, 11 females) who underwent neuropsychological evaluations prior to and following open brain resection surgery (i.e., temporal lobectomy, temporal resection, frontal lobectomy). Verbal Fluency was assessed by the Delis-Kaplan Executive Functioning System (D-KEFS), measuring phonemic fluency, categorical fluency, switching accuracy, and the number of switches. Results Statistically significant differences were found between groups on the D-KEFS Verbal Fluency subtest using a one-way ANOVA. Specifically, switching accuracy decreased following surgery, F(1,25) = 6.470, p = 0.02 (M = 104.44 pre-surgery, M = 89.44 post-surgery). Further, a downward trend was noted regarding the number of switches between the two groups, F (1, 26) = 3.172, p = 0.09; however, no differences were found in phonemic, F(1,34) = 0.854, p = 0.63, and categorical, F(1,35) = 0.828, p = 0.37, fluency tasks. Conclusions Results from this study revealed a decrease in the participants ability to accurately switch between verbal categories following brain resection surgery. Similarly, a downward trend was noted for number of switches completed pre- and post- surgery. Consistent with previous research, phonemic and semantic verbal fluency tasks remain unchanged post-surgery. Implications of this study highlight the need to assess executive functioning after surgery as it has an impact on treatment outcome and school planning.

A-38 Examining Cognitive Differences of Pre- and Post- Surgery in Pediatric Epilepsy

Abstract Objective Intractable epilepsy is often associated with cognitive difficulties in the language domain. Few studies examining verbal domains of cognitive functioning indicate a small increase of verbal skills post-surgery. The current study compared Verbal IQ and Performance IQ domains in pediatric populations before and after open resection surgery. Method Participants included 31 epilepsy patients (age 5-20 years old; M = 12.23 years pre-surgery; M = 14.72 years post-surgery; 20 males, 11 females) who underwent neuropsychological evaluations prior to and following an open brain resection surgery (i.e., temporal lobectomy, temporal resection, frontal lobectomy). Cognitive ability was assessed by Weschler Abbreviated Scale of Intelligence (WASI) in order to analyze differences between pre-surgical and post-surgical cognitive function, specifically verbal comprehension and perceptual reasoning ability. Results No statistically significant differences were found, using a One-way ANOVA, between the two groups; however, a downward trend was noted for the Verbal IQ (VIQ) domain, F(1, 25) = 2.624, p = 0.118, including the verbal subtests vocabulary, F(1, 23) = 2.203, p = 0.151, and similarities, F(1, 24) = 1.678, p = 0.207. No differences or trends were noted within the Performance IQ (PIQ) domain, block design, or matrix reasoning. Conclusions Findings indicated that participants verbal ability decreased after epilepsy surgery when compared to prior evaluations. This is not consistent with previous research, which stated an increase in verbal abilities following surgical resection. Variable time between surgery and re-evaluation might account for discrepancies. Further, no differences in nonverbal reasoning abilities were noted. Results indicated a need for further research in open brain resection surgeries and the outcome of verbal processing.

Ictal High-Frequency Oscillation for Lateralizing Patients With Suspected Bitemporal Epilepsy Using Wavelet Transform and Granger Causality Analysis.

Identifying lateralization of bilateral temporal lobe epilepsy (TLE) is a challenging issue; scalp electroencephalography (EEG) and routine band electrocorticography (ECoG) fail to reveal the epileptogenic focus for further temporal lobectomy treatment. High-frequency oscillations (HFOs) can be utilized as a biomarker for lateralizing the onset zone in suspected bitemporal epilepsy. Except subjective vision detect the HFOs, objective verification should be performed to raise the accuracy. In the present research, we prospectively studied 10 patients with refractory temporal seizures and who underwent ECoG with wide-band frequency amplifiers (2,048 Hz); all patients had a class I outcome after temporal resection. Pre- and ictal HFOs will be analyzed by wavelet transform (WT) and Granger causality (GC) to objectively verify lateralization of the seizure onset zone (SOZ). WT analysis showed ictal HFOs in 10 patients mainly covered from 80 to 115 Hz (average, 92.59 ± 10.23 Hz), and there was distinct bandpass boundary between pre-ictal HFOs and ictal HFOs. GC analysis showed five patients (2, 4, 5, 6, and 7), no matter the pre-ictal or ictal state, had the highest GC degree in SOZ itself. The remaining patients (1, 3, 8, 9, and 10) had the highest GC degree in SOZ with its adjacent regions in the pre-ictal and ictal stages. GC analysis further confirmed the result of the WT and suggested HFOs are initiated and propagated in the local brain region mainly, afterward, transmitting to adjacent brain regions. These results indicated that the combination of WT and GC analyses significantly contributes to accurate lateralization in patients with suspected bitemporal epilepsy.

Use of three-dimensional printing for reconstruction of a cranial surgical defect for mucormycosis with a preformed titanium cranial mesh implant

Background: Introduction It is important to reconstruct the skull for the recovery of a patient's quality of life. There are different methods and materials available for cranioplasty. Points to be considered are the resistance to stress of the material, good adaptation to the contour of the cranial defect, surgical operating time, risk of infection and aesthetic results. Clinical case A fifty three year old male patient presented with a severe cranial defect after right fronto orbito temporal and orbito zygomatic partial resection for mucormycosis. He had undergone three surgical procedures of resection. He had also received specific antimycotic treatment with good response but showed severe craniofacial sequelae.

Gyratory seizures as a presentation of temporal encephalocele.

Gyratory seizures (GS) are rare and have been reported in focal (frontal and temporal) as well as generalized epilepsies. The exact neuroanatomical substrate of gyration during a seizure is not clearly understood, but is thought to be due to the involvement of the basal ganglia. The direction of gyration occurring without head version is thought to have ipsilateral cerebral origins, while gyrational seizures preceded by forced head version are suggestive of seizure onset contralateral to the direction of gyration or the presence or absence of forced head version is thought to have important implications for lateralization of seizure origins from the direction of gyration. This case describes gyratory seizures in a young boy with a temporal encephalocele. Report of MRI brain initially indicated no abnormalities, but careful review revealed a left temporal encephalocele. PET scan showed left temporal hypometabolism. The patient underwent a left anterior temporal resection with amygdalohippocampectomy (ATL + AH) and is seizure‐free for 18 months. Temporal encephalocele is the most commonly iatrogenic but may also be spontaneous, post‐traumatic, or in relation to chronic otitis media. This case suggests that gyratory seizures may be a unique presentation of temporal encephalocele and this possibility warrants investigation in patients with medically refractory epilepsy.

Determinants of IQ outcome after focal epilepsy surgery in childhood: A longitudinal case-control neuroimaging study.

Intelligence quotient (IQ) outcomes after pediatric epilepsy surgery show significant individual variation. Clinical factors such as seizure cessation or antiepileptic medication discontinuation have been implicated, but do not fully account for the heterogeneity seen. Less is known about the impact of neurobiological factors, such as brain development and resection location. This study examines clinical and neuroimaging factors associated with cognitive outcome after epilepsy surgery in childhood. Fifty-two children (28 boys, 24 girls) were evaluated for epilepsy surgery and reassessed on average 7.7years later. In the intervening time, 13 were treated pharmacologically and 39 underwent focal surgery (17 temporal, 16 extratemporal, six multilobar; mean age at surgery = 14.0years). Pre- and postsurgical assessments included IQ tests and T1-weighted brain images. Predictors of IQ change were investigated, including voxel-based analyses of resection location, and gray and white matter volume change. Overall modest IQ improvement was seen in children treated surgically, but not in those treated pharmacologically only. Applying a ≥10-point change threshold, 39% of the surgically treated children improved, whereas 10% declined. Clinical factors associated with IQ increases were lower preoperative IQ and longer follow-up duration, whereas seizure and antiepileptic medication cessation were not predictive. Among neuroimaging factors, we observed that left anterior temporal resections impacted negatively on verbal reasoning, linked to full-scale IQ decline. In contrast, gray matter volume change in ipsi- and contralesional hemispheres was positively correlated with IQ change. Voxel-based morphometry identified the gray matter volume change in the contralesional dorsolateral frontal cortex as most strongly associated with IQ improvement. We show that a variety of factors are likely to contribute to patterns of postsurgical change in IQ. Neuroimaging results indicate that left anterior temporal resections constrain development of verbal cognition, whereas simultaneously cortical growth after surgical treatment can support improvements in IQ.

Voxel-based morphometric magnetic resonance imaging postprocessing in non-lesional pediatric epilepsy patients using pediatric normal databases.

Pre-surgical evaluation of pediatric patients with drug-resistant focal epilepsy and negative (non-lesional) magnetic resonance imaging (MRI) is particularly challenging. Focal cortical dysplasia (FCD), a frequent pathological substrate in such setting, may be subtle on MRI and evade detection. The aim of this study was to use voxel-based MRI postprocessing to improve the detection of subtle FCD in pediatric surgical candidates. A consecutive cohort of pediatric patients undergoing pre-surgical evaluation with a negative MRI by visual analysis was included. MRI postprocessing was performed using a voxel-based morphometric analysis program (MAP) on T1-weighted volumetric MRI, with comparison to an age-specific normal pediatric database. The pertinence of MAP-positive areas was confirmed by surgical outcome and pathology. A total of 78 patients were included. Forty-four patients (56%) had positive MAP regions. Complete resection of the MAP-positive regions was positively associated with seizure-free outcome compared with the no/partial resection group (P < 0.001). Patients with no/partial resection of the MAP-positive regions had worse seizure outcomes than the MAP-negative group (P = 0.002). The MAP-positive rate was 100%, 77%, 63% and 40% in the 3-5, 5-10, 10-15 and 15-21 year age groups, respectively. MAP-positive rates were 45% in patients with temporal resection and 63% in patients with extratemporal resection. Complete resection of the MAP-positive regions was positively associated with seizure-free outcome in the extratemporal group (P = 0.001) but not in the temporal group (P = 0.070). Our data suggest the importance of using MRI postprocessing in the pre-surgical evaluation process of pediatric epilepsy patients with apparently normal MRI.

Improved Detection of Subtle Mesial Temporal Sclerosis: Validation of a Commercially Available Software for Automated Segmentation of Hippocampal Volume.

Identification of mesial temporal sclerosis is critical in the evaluation of individuals with temporal lobe epilepsy. Our aim was to assess the performance of FDA-approved software measures of hippocampal volume to identify mesial temporal sclerosis in patients with medically refractory temporal lobe epilepsy compared with the initial clinical interpretation of a neuroradiologist. Preoperative MRIs of 75 consecutive patients who underwent a temporal resection for temporal lobe epilepsy from 2011 to 2016 were retrospectively reviewed, and 71 were analyzed using Neuroreader, a commercially available automated segmentation and volumetric analysis package. Volume measures, including hippocampal volume as a percentage of total intracranial volume and the Neuroreader Index, were calculated. Radiologic interpretations of the MR imaging and pathology from subsequent resections were classified as either mesial temporal sclerosis or other, including normal findings. These measures of hippocampal volume were evaluated by receiver operating characteristic curves on the basis of pathologic confirmation of mesial temporal sclerosis in the resected temporal lobe. Sensitivity and specificity were calculated for each method and compared by means of the McNemar test using the optimal threshold as determined by the Youden J point. Optimized thresholds of hippocampal percentage of a structural volume relative to total intracranial volume (<0.19%) and the Neuroreader Index (≤-3.8) were selected to optimize sensitivity and specificity (89%/71% and 89%/78%, respectively) for the identification of mesial temporal sclerosis in temporal lobe epilepsy compared with the initial clinical interpretation of the neuroradiologist (50% and 87%). Automated measures of hippocampal volume predicted mesial temporal sclerosis more accurately than radiologic interpretation (McNemar test, P < .0001). Commercially available automated segmentation and volume analysis of the hippocampus accurately identifies mesial temporal sclerosis and performs significantly better than the interpretation of the radiologist.

Is additional mesial temporal resection necessary for intractable epilepsy with cavernous malformations in the temporal neocortex?

PurposeCavernous malformation (CM) in the temporal neocortex causes intractable epilepsy. Whether to resect additional mesial temporal structures in addition to the lesionectomy is a still controversial issue. To clarify the need for the procedure, we retrospectively analyzed pre- and postoperative clinical data of patients with surgically removed CM. Subjects and methodsWe included data from 18 patients with CM in the temporal neocortex who presented with intractable epilepsy. Eleven patients of our early series were treated with extended resection, i.e., lesionectomy and the resection of additional mesial temporal structures. Seven patients underwent lesionectomy, i.e., removal of the CM and of hemosiderin-stained surrounding brain tissue. Pathological assessments of the resected hippocampus were performed. Chronic intracranial electroencephalography (EEG) recordings were obtained in 6 patients. We performed perioperative neuropsychological assessments in all patients. ResultsThe seizure outcome was recorded as Engel class I in 17 patients (94.4%); Ia = 12 (66.7%) Ib = 2 (11.1%), Ic = 1 (5.6%), Id = 2 (11.1%), and class IIb in one patient (5.6%). Adding resection of the mesial temporal structures to lesionectomy did not alter the seizure outcome. Pathology of hippocampus revealed limited neuronal loss in CA4. Ictal onsets in the ipsilateral lateral cortex were detected in all 6 patients who underwent intracranial EEG. In 4 patients each, we also detected ictal onsets from the ipsilateral mesial temporal structures and from the contralateral temporal lobe. Postoperatively, in the patients where their CM was located in the language-dominant hemisphere (n = 10), the full-scale intelligence quotient (IQ) and the performance IQ increased (p < 0.05), whereas the verbal memory (WMS-R) deteriorated in two of 5 patients. ConclusionExcellent seizure outcomes were obtained even the lesionectomy alone. To confirm appropriate surgical strategy for lateral temporal CM with intractable epilepsy, further studies in large sample size are needed.

Association of Seizure Spread With Surgical Failure in Epilepsy

Seizures recur in as many as half of patients who undergo surgery for drug-resistant temporal lobe epilepsy (TLE). Understanding why TLE is resistant to surgery in some patients may reveal insights into epileptogenic networks and direct new therapies to improve outcomes. To characterize features of surgically refractory TLE. Medical records from a comprehensive epilepsy center were retrospectively reviewed for 131 patients who received a standard anteromedial temporal resection by a single surgeon from January 1, 2000, to December 31, 2015. Thirteen patients were excluded for having less than 1 year of follow-up. Patients at the highest risk for seizure recurrence were identified. Intracranial electroencephalogram (iEEG) analyses generated 3-dimensional seizure spread representations and quantified rapid seizure spread. The final analyses of seizure outcome and follow-up data were performed in June 2017. The Engel class seizure outcome following surgery was evaluated for all patients, defining seizure recurrence as Engel class II or greater. Intracranial recordings of neocortical grids/strips and depth electrodes were analyzed visually for seizure spread. Fast β power was projected onto reconstructions of patients' brain magnetic resonance imaging scans to visualize spread patterns and was quantified to compare power within vs outside resective margins. Of 118 patients with 1 year of follow-up or more (mean [SD], 6.5 [4.6] years), 66 (55.9%) were women and 52 (44.1%) were men (median age, 39 years [range, 4-66 years]). The cumulative probability of continuous Engel class I seizure freedom since surgery at postoperative year 10 and afterward was 65.6%, with 92% of recurrences in years 1 to 3. Multivariable statistical analyses found that the selection for iEEG study was the most reliable predictor of seizure recurrence, with a mixed-effects model estimating that the Engel score in the iEEG cohort was higher by a mean (SD) of 1.1 (0.33) (P = .001). In patients with iEEG results, rapid seizure spread in less than 10 seconds was associated with recurrence (hazard ratio, 5.99; 95% CI, 1.7-21.1; P < .01). In the first 10 seconds of seizures, fast β power activity outside the resective margins in the lateral temporal cortex was significantly greater in patients whose seizures recurred compared with patients who were seizure-free (mean [SEM], 137.5% [16.8%] vs 93.4% [4.6%]; P < .05). Rapid seizure spread outside anteromedial temporal resection resective margins plays a significant role in the surgical failure of drug-resistant TLE. Seizure control after epilepsy surgery might be improved by investigating areas of early spread as candidates for resection or neuromodulation.

Cognitive outcomes more than 5 years after temporal lobe epilepsy surgery: Remarkable functional recovery when seizures are controlled

PurposeEpilepsy surgery can be a successful treatment option for temporal lobe epilepsy but there are concerns about accelerated memory decline in long-term follow-up. Method161 adult operated (77 right, 84 left temporal resections) versus a heterogeneous group of 208 non-operated patients with focal epilepsies were consecutively recruited and re-evaluated focusing on memory, executive functions, and vocational outcome after follow-up intervals of >5 years (5–22 years, mean 8 ± 3 years). ResultsMajor losses in the operated group manifest early, at one-year follow-up. Few patients declined further. Long-term changes after surgery did not differ from those observed without surgery. The factor “surgery” caused verbal memory decline, “seizure freedom” (operated 48%, non-operated 17%) was associated with recovery of verbal memory, and “drug reduction” positively affected the course of executive functions. In terms of the critical function of verbal memory, only 3–17% of seizure-free patients showed long-term decline whereas 16–20% showed improvement (operated and non-operated). Persistent seizures were associated with decline in 12–37% and improvement in 4–12% of patients. Improvement was related to longer retest intervals and was stronger in younger patients. Independent of surgery or seizure outcome, the vocational status remained unchanged or change was negative (22%) rather than positive (3%). ConclusionsPatients’ cognitive course 5–22 years after surgery is stable and may even be positive if epilepsy is controlled and drug load reduced. Depending on seizure outcome, recovery is more frequently observed than continuing decline. Recovery, however, takes time and age is a limiting factor.

P01.164 Cognitive and neuropsychological outcome after awake surgery for left frontal and left temporal tumor resection

P01.164 Cognitive and neuropsychological outcome after awake surgery for left frontal and left temporal tumor resection

B - 16Neuropsychological Functioning of Early Childhood Left Temporal Primary CNS Neoplasm Status-Post Resection: Evidence for the “Crowding Out” Hypothesis

B - 16Neuropsychological Functioning of Early Childhood Left Temporal Primary CNS Neoplasm Status-Post Resection: Evidence for the “Crowding Out” Hypothesis

Endoscopy in Temporal Lobe Glioma and Metastasis Resection: Is There a Role?

Surgical access to the temporal lobe is complex with many eloquent white fiber tracts, requiring careful preoperative surgical planning. Many microsurgical approaches to the temporal lobes are described, each with their own disadvantages. The adoption of the endoscope in neurosurgery has increased the options available when treating these difficult access tumors. We present our experience of a novel, minimally invasive, endoscopic approach to resect temporal lobe tumors. All patients undergoing endoscopic temporal lobe tumor resection between December 1, 2011 and December 1, 2017, with a single surgeon, were included. Tumors were resected through a minicraniotomy using a high-definition rigid endoscope with a 0- and 30-degree viewing angle. Bimanual resection was performed using standard microsurgical technique. There were 45 patients (22 men and 23 women) with a mean age of 53 years. There were 23 (51%) glioblastoma multiforme, 11 (24%) metastases, 7 (16%) astrocytoma, 3 (7%) anaplastic astrocytoma, and 1 (2%) World Health Organization grade I glioneuronal tumor. In 82.2% of cases (37/45), >95% resection was achieved and 42.2% (19/45) of patients achieving gross total resection. The endoscope has a role in temporallobe intraparenchymal tumor surgery, especiallyin3illustrative scenarios: 1) medial temporal, parahippocampal-gyruslow-grade nonenhancing gliomas, 2) subcortical high-gradeglioma and metastases medial to the sagittal stratum, and 3) recurrent gliomas with cystic resection cavity. The endoscope offers a safe and useful adjunct to the surgeons' armamentarium in brain tumor surgery. A minimally invasive approach also reduces surgical morbidity and length of stay.