Visual phenomena and anatomo-electro-clinical correlations in occipital lobe seizures.

BACKGROUND: Occipital lobe seizure are underrepresented in epilepsy surgery cases series. This may reflect the fear for post-surgical functional deficits but also the doubt about the ability of anatomo-electro-clinical correlations to localize precisely the epileptogenic zone in occipital lobe seizure. METHODS: In this expert opinion paper, we review first the general clinical characteristics of occipital lobe seizures, describe the repertoire of visual phenomena and oculo-motor signes in occipital seizures, describe inter-ictal and ictal EEG and finally the possible schemes of epileptogenic zone organization. RESULTS: Visual and oculo-motor semiology points towards occipital onset seizures but is neither pathognomonic nor constant. Eyes version and unilateral ictal discharge have a strong lateralizing value but inter-ictal spikes as well as eyes version can be falsely lateralizing. CONCLUSION: Although visual and oculo-motor phenomena are characteristic of occipital lobe seizures, they may be discrete, overlooked and should therefore be carefully assessed. There are no clear electro-clinical correlations of a sublobar organization of occipital seizures but the clinical pattern of propagation might help to differentiate complex occipito-temporal from occipito-parietal initial epileptogenic network.

Epilepsy surgery for drug-resistant temporal lobe epilepsy in over-50 year-olds: Seizure outcome, surgical complications and neuropsychological outcome.

OBJECTIVE: Surgery is an effective treatment for drug-resistant temporal-lobe epilepsy (TLE), but is still underutilized for older patients because of a perceived higher rate of perioperative complications, cognitive decline and worse seizure outcome. METHODS: We retrospectively screened all patients operated on in our institution for drug-resistant TLE between 2007 and 2019. Data of patients aged ≥50 years versus <50 years at surgery were compared. The primary endpoint was freedom from disabling seizure (Engel I) at 2 years postoperatively. RESULTS: In patients aged ≥50 years (n=19), mean age at surgery was 54.9 years and mean disease duration was 36.6 years. At 2 years postoperatively, rates of Engel I seizure outcome were not significantly different between the two groups (73.9% in the <50 years group versus 94.4% in the ≥50 years group). Although surgical complications were significantly (47.4%) in the older patients, neurological deficit was permanent in only 5.3% of cases. At 1 year postoperatively, neuropsychological outcome did not significantly differ between the two groups. CONCLUSIONS: Patients aged ≥50 years had an excellent seizure outcome at 2 years postoperatively. Early postoperative complications were more frequent in patients aged ≥50 years but were mostly transient. Cognitive outcome was similar to that in younger patients. These findings strongly suggest that age ≥50 years should not be an exclusion criterion for resective epilepsy surgery in patients with drug-resistant TLE.

Psychogenic nonepileptic seizures: characterization of two distinct patient profiles on the basis of trauma history.

This prospective study investigated and compared psychiatric features of 25 consecutive patients with psychogenic nonepileptic seizures (PNES) on the basis of presence of reported trauma. The "trauma" group comprised 19 patients (76%) and the "no-trauma" group comprised 6 patients (34%). We compared history of PNES, psychiatric comorbidity, alexithymia, and symptoms of dissociation. The study clearly characterized two distinct profiles of patients with PNES on the basis of trauma history. Patients with trauma had at least one psychiatric comorbidity or antecedent (vs 0% in the no-trauma group NT, P<0.001) and a higher median score of dissociation (P<0.001). Patients without trauma had more frequent "frustration situations" as a factor triggering PNES and subsequent sick leaves as perpetuating factors (P=0.001). Trauma antecedents correlated with a high rate of psychiatric comorbidity and a strong dissociative mechanism. Patients without trauma had no psychiatric comorbidity and a weaker dissociative mechanism.

Drug-resistant temporal lobe epilepsy is associated with postural control abnormalities.

Epilepsy is responsible for falls that are not systematically associated with seizures and that therefore suggest postural impairment. There are very few studies of postural control in patients with epilepsy and none of them focus on temporal lobe epilepsy (TLE), although part of the vestibular cortex is located in the temporal cortex. The aim of this study was to evaluate the characteristics of postural control in a homogeneous population of patients with complex partial TLE. Twenty-six patients with epilepsy and 26 age-matched healthy controls underwent a sensory organization test combining six conditions, with and without sensory conflicting situations. Patients with epilepsy displayed poorer postural control, especially in situations where vestibular information is necessary to control balance. In addition to potential antiepileptic drug side effects, vestibular dysfunction could be related to the temporal pathology. Our study allows for a better understanding of the mechanism underlying falls in this population of patients.

[Memory improvement in patients with temporal lobe epilepsy at one-year postoperative]. / Amélioration mnésique postopératoire un an après traitement chirurgical de l'épilepsie du lobe temporal.

INTRODUCTION: Several studies have assessed the impact of surgery on both anterograde and remote memory in patients with temporal lobe epilepsy (TLE). The majority of results have shown an extensive memory deficit in patients after temporal resection (TL). However, few protocols have used a prospective longitudinal design. Moreover, the postoperative delays were variable from one study to the next, instead of regular monitoring to identify the potential effect of time elapsed after surgery on memory performance. In addition, some studies have not used strict inclusion criteria to establish homogeneous patient groups. Finally, the impact of surgery on memory has been often assessed by comparing memory skills between epileptic patients and healthy controls. Our aim was to examine the impact of TL on memory in patients with TLE, recruited according to clear-cut clinical criteria. Moreover, we focused on memory performance progression per se in epileptic patients pre- and postoperatively, rather than on memory performance analysis expressed as "deficient" or "normal". METHODS: We assessed 30 patients with unilateral TLE (17 right TLE and 13 left TLE) on four anterograde memory tests and six remote memory tasks. Patients completed all tests preoperatively, and 5 and 12 months after TL. RESULTS: Five months after surgery, performance was equivalent to the preoperative scores for both groups in anterograde memory tasks and remote memory tests. One year after TL, patients with right TLE showed enhanced performance in the verbal anterograde memory tests and in retrieving recent autobiographical memories. Results for left TL showed improved scores only in a recognition memory test of faces. CONCLUSIONS: In the present study, surgical patients were "double winners" gaining seizure freedom and potential of memory stability or recovery. The gain was observed only 12 months after surgery and following temporal resection lateralisation. Our data showed postoperative memory improvement in patients with temporal lobe epilepsy presenting with specific clinical characteristics.

Automated cortical projection of EEG sensors: anatomical correlation via the international 10-10 system.

Several studies have described cranio-cerebral correlations in accordance with the 10-20 electrode placement system. These studies have made a significant contribution to human brain imaging techniques, such as near-infrared spectroscopy and trans-magnetic stimulation. With the recent development of high resolution EEG, an extension of the 10-20 system has been proposed. This new configuration, namely the 10-10 system, allows the placement of a high number (64-256) of EEG electrodes. Here, we describe the cranio-cerebral correlations with the 10-10 system. Thanks to the development of a new EEG-MRI sensor and an automated algorithm which enables the projection of electrode positions onto the cortical surface, we studied the cortical projections in 16 healthy subjects using the Talairach stereotactic system and estimated the variability of cortical projections in a statistical way. We found that the cortical projections of the 10-10 system could be estimated with a grand standard deviation of 4.6 mm in x, 7.1 mm in y and 7.8 mm in z. We demonstrated that the variability of projections is greatest in the central region and parietal lobe and least in the frontal and temporal lobes. Knowledge of cranio-cerebral correlations with the 10-10 system should enable to increase the precision of surface brain imaging and should help electrophysiological analyses, such as localization of superficial focal cortical generators.

[Risk of epilepsy after a first epileptic seizure in adults: Can we predict the future?]. / Prise en charge d'une première crise épileptique de l'adulte : peut-on prévoir l'avenir ?

The new definition of epilepsy recently proposed by an international panel of experts relies on the association of a first clinically certain seizure and of an enduring predisposition of the brain increasing the likelihood of future seizures. In the first part of this review, we will expose and organize into a hierarchical order the risk factors of subsequent recurrence. The major factors are: seizure(s) prior to presentation, paroxysmal abnormalities on early EEG, a remote symptomatic etiology. In the second part of this review, we will address the issue of clinical uncertainty when assessing the epileptic origin of a first clinical paroxysmal event, the reasons of uncertainty and the means to minimize it. We will analyze successively: the accuracy of eyewitness observations of transient loss of consciousness, the reliability and predictive validity of clinical criteria used for seizure assessment, the issue of overlapping clinical features between seizure and other non epileptic paroxysmal events (such as psychogenic non epileptic seizures), and finally the reliability and diagnostic value of early EEG for seizure assessment. To conclude, seizure assessment and diagnosis of epilepsy cannot be dissociated from syndrome and etiology diagnosis, which should be periodically reassessed towards a greater accuracy during the course of the disease.

[Medicoeconomic assessment of epilepsy surgery in adults with medically intractable partial epilepsy. Three-year outcomes from a multicenter French cohort]. / Evaluation médicoéconomique de la chirurgie des épilepsies partielles pharmacorésistantes de l'adulte. Résultats à trois ans d'une étude prospective multicentrique française.

PURPOSE: To compare resective surgery and medical therapy in a cost-effectiveness analysis in a multicenter cohort of adult patients with partial intractable epilepsy. POPULATION AND METHODS: Adult patients with partial, medically intractable, potentially operable epilepsy were eligible and followed every year over five years. Effectiveness was defined as one year without seizure. The long-term costs and effectiveness were extrapolated over the patients' lifetime with a Markov model. Productivity (indirect costs) and quality of life (QOLIE-31, SEALS) were also assessed. Changes before and after surgery were compared between the two groups. RESULTS: Two hundred and eighty-nine patients were included (119 with surgery, 161 medically treated, six not eligible, three lost to follow-up). One year after surgery, 81% of the patients were seizure-free; at two and three years, this rate was 78%. In the medical group, these rates were 10, 18, and 15%, respectively. The cost of the explorations was euro 8464; including surgery, it was euro 19,700. In the medical group, the average annual direct costs were between 3500 and euro 6000. At two years after surgery, the annual direct cost decreased to euro 2768, at three years, it was euro 1233, predominately antiepileptic drug costs. Surgery became cost-effective between seven and eight years. In the surgical group, all the quality-of-life scores improved at one year after surgery and were stable during the second and third years. CONCLUSION: Surgical therapy was cost-effective at the middle term even though indirect costs were not considered.

Spatial localization of EEG electrodes.

AIM OF THE STUDY: An important goal for EEG-based functional brain studies is to estimate the location of brain sources that produce the scalp-recorded signals. Such source localization requires locating precisely the position of the EEG sensors. This review describes and compares different methods that are used for localizing EEG sensors. RESULTS: Five different methods have been described in literature. Manual methods consist in manual measurements to calculate the 3D coordinates of the sensors. Electromagnetic and ultrasound digitization permit localization by using trade devices. The photogrammetry system consists in taking pictures of the patient's head with the sensors. The last method consists in directly localizing the EEG sensors in the MRI volume. DISCUSSION AND CONCLUSIONS: The spatial localization of EEG sensors is an important step in performing source localization. This method should be accurate, fast, reproducible, and cheap. Currently, electromagnetic digitization is the most currently used method but MRI localization could be an interesting way because no additional method or device needs to be used to locate the EEG sensors.

[Rectal amputation by pure perineal approach with laparoscopic colostomy: a palliative therapeutic option for low rectal or anal cancers for elderly patients with multiple comorbidities]. / Amputation du rectum par voie périnéale pure avec colostomie coelio-assistée: une option thérapeutique palliative pour les cancers du bas rectum ou de l'anus chez le sujet âgé ou multitaré.

Rectal syndrome caused by locoregional evolution of low rectal cancers and anal cancers is prevented and treated by surgical resection. But, for old patients with multiple tares, carcinologic surgical resection as abdominoperineal amputation can not be considered. Management of rectal syndrome becomes a therapeutic challenge. We reported a prospective serie of 5 patients more than 80 years old with multiple tares, treated by rectal amputation by pure perineal approach with laparoscopic colostomy. This surgery avoided for all patients trying rectal symptoms and maintained acceptable quality of life with fast coming back at home. The palliative treatment of low rectal cancers or anal cancers combining rectal amputation by pure perineal approach with laparoscopic colostomy may be an interesting therapeutic option for patients who cannot undergoing aggressive carcinologic surgical treatment.

Surgery combined with peritonectomy procedures and intraperitoneal chemohyperthermia in abdominal cancers with peritoneal carcinomatosis: a phase II study.

PURPOSE: To evaluate the tolerance of peritonectomy procedures (PP) combined with intraperitoneal chemohyperthermia (IPCH) in patients with peritoneal carcinomatosis (PC), a phase II study was carried out from January 1998 to September 2001. PATIENTS AND METHODS: Fifty-six patients (35 females, mean age 49.3) were included for PC from colorectal cancer (26 patients), ovarian cancer (seven patients), gastric cancer (six patients), peritoneal mesothelioma (five patients), pseudomyxoma peritonei (seven patients), and miscellaneous reasons (five patients). Surgeries were performed mainly on advanced patients (40 patients stages 3 and 4 and 16 patients stages 2 and 1) and were synchronous in 36 patients. All patients underwent surgical resection of their primary tumor with PP and IPCH (with mitomycin C, cisplatinum, or both) with a closed sterile circuit and inflow temperatures ranging from 46 degrees to 48 degrees C. Three patients were included twice. RESULTS: A macroscopic complete resection was performed in 27 cases. The mortality and morbidity rates were one of 56 and 16 of 56, respectively. The 2-year survival rate was 79.0% for patients with macroscopic complete resection and 44.7% for patients without macroscopic complete resection (P =.001). For the patients included twice, two are alive without evidence of disease, 54 and 47 months after the first procedure. CONCLUSION: IPCH and PP are able to achieve unexpected long-term survival in patients with bulky PC. However, one must be careful when selecting the patients for such an aggressive treatment, as morbidity rate remains high even for an experienced team.

Influence of the interval between preoperative radiation therapy and surgery on downstaging and on the rate of sphincter-sparing surgery for rectal cancer: the Lyon R90-01 randomized trial.

PURPOSE: The optimal timing of surgery after preoperative radiotherapy in rectal cancer is unknown. The aim of this trial was to evaluate the role of the interval between preoperative radiotherapy and surgery. PATIENTS AND METHODS: Patients with rectal carcinoma accessible to rectal digital examination, staged T2 to T3, NX, M0, were randomized before radiotherapy (39 Gy in 13 fractions) into two groups: in the short interval (SI) group, surgery had to be performed within 2 weeks after completion of radiation therapy, compared with 6 to 8 weeks in the long interval (LI) group. Between 1991 and 1995, 201 patients were enrolled onto the study. RESULTS: A long interval between preoperative radiotherapy and surgery was associated with a significantly better clinical tumor response (53. 1% in the SI group v 71.7% in the LI group, P =.007) and pathologic downstaging (10.3% in the SI group v 26% in the LI group, P =.005). At a median follow-up of 33 months, there were no differences in morbidity, local relapse, and short-term survival between the two groups. Sphincter-preserving surgery was performed in 76% of cases in the LI group versus 68% in the SI group (P = 0.27). CONCLUSION: A long interval between preoperative irradiation and surgery provides increased tumor downstaging with no detrimental effect on toxicity and early clinical results. When sphincter preservation is questionable, a long interval may increase the chance of a successful sphincter-saving surgery.

Intraoperative radiation therapy combined with limited lymph node resection in gastric cancer: an alternative to extended dissection?

PURPOSE: To describe the results of a series of 63 Western patients presenting with gastric adenocarcinoma and treated with surgery and intraoperative radiation therapy (IORT) over a 8-year period and to discuss the role of IORT when combined with limited lymph node dissection. METHODS AND MATERIALS: From 1986 to 1993, 63 patients with gastric adenocarcinoma have been operated in the department of radiation oncology of the Hospices Civils de Lyon. The stage was: I in 17, II in 11, IIIA in 9, IIIB in 20, and IV in 6. The lymph node dissection was considered to be limited in 56 patients and extended in 7. The IORT dose ranged from 12 to 23 Gy (median: 15). Thirty patients also underwent a postoperative external beam irradiation with a standard dose of 44-46 Gy. RESULTS: The postoperative mortality rate was 4.8%. The 5-year overall survival in the entire series was 47% and was 82, 55, 78, 20, and 0% in Stages I, II, IIIA, IIIB, and IV, respectively. Loco-regional relapse occurred in 15 of 63 patients and metastases in 15 of 63. CONCLUSION: In Western patients treated by gastrectomy for adenocarcinoma of the stomach, IORT combined with limited lymph node dissection may provide overall survival similar to that observed after gastrectomy with extended lymph node dissection but with less postoperative mortality.

Ictal cerebral blood flow in seizures originating in the posterolateral cortex.

UNLABELLED: In selecting patients for epilepsy surgery, it is important to distinguish mesial temporal seizures from seizures originating in the posterolateral cortex. We studied ictal cerebral perfusion in five patients with complex partial seizures with clear posterior EEG ictal onsets and clinical seizures semiology suggesting seizure origin in the posterolateral cortex. METHODS: Ictal SPECT was performed during video EEG monitoring using 99mTc-HMPAO as a cerebral perfusion tracer and a rotating gamma camera to acquire images. RESULTS: Three patterns of ictal hyperperfusion were seen: pattern A = temporoparieto-occipital junction extending into the lateral temporal cortex, involving the mesial temporal cortex and basal ganglia to a lesser degree and a small area of hyperperfusion in the contralateral parietal cortex (two patients); pattern B = pattern A but with no hyperperfusion of the mesial temporal cortex (one patient); and pattern C = localized hyperperfusion in the area of the temporoparieto-occipital junction (two patients). CONCLUSION: Our results suggest distinct patterns of ictal perfusion in seizures with posterolateral ictal EEG onsets. Ictal SPECT may be useful in distinguishing such seizures.

Pattern of failures in gastric cancer patients with lymph node involvement treated by surgery, intraoperative and external beam radiotherapy.

AIMS: High local failure rates in gastric cancer have been reported, up to 67%. To achieve a better local control, we evaluated intraoperative radiotherapy (IORT) and external beam radiotherapy (EBRT) in association with surgery for gastric cancer patients with lymph node involvement. We report here the analysis of the patterns of failure for patients involved in this IORT protocol. MATERIAL AND METHODS: Forty-two positive lymph node (N+) gastric cancer patients were operated on (31 total, three subtotal and eight extended gastrectomies) with IORT procedure between 1985 and 1997 (33 males, nine females, mean age 61.3 years). IORT was focused on coeliac area (mean dose 15 Gy), followed by EBRT (46 Gy) in 36 patients. Ten patients were pN1 and 32 were pN2. A concurrent systemic chemotherapy (five Fluoro-Uracil and Cisplatinum) was performed in 14 patients. RESULTS: One patient died postoperatively. Actuarial pN+ 10 year survival rate was 44.8%. The 5 year actuarial local control and disease-free survival rates were 78.8 and 47.5%, respectively. As far as patterns of failure were explored, 5 patients have a local coeliac recurrence (12%) and 12 have distant metastases with no evidence of coeliac recurrence. CONCLUSION: This retrospective analysis suggests a potential effect of IORT and/or EBRT in promoting local control and long-term survival in gastric cancer patients with lymph node involvement.

Long-term results of surgical treatment for gastroesophageal reflux in asthmatic patients.

We report the long-term results of surgical repair of gastroesophageal reflux in 44 asthmatic patients who underwent surgery more than five years earlier (mean = 7.9 +/- 1.5 years). The severe asthma was associated with clinically evident reflux, and repair was attempted by surgical technique Nissen transabdominal gastropexy, with the following results: total cure, 11 cases (25 percent); marked improvement, 7 (16 percent); moderate improvement, 11 (25 percent); no improvement, 15 (34 percent). Cure was attained in intrinsic asthma with a predominance of nocturnal crises, associated with nocturnal tracheitis and with significant reflux, objective signs of which had appeared before the beginning of the asthma. Other results concerned asthmas complicated secondarily by GER in which it was impossible to determine whether the reflux was only a complication, without effect on the respiratory illness, or exacerbating the asthma. The question of surgery in these patients should be considered with care, being reserved for cases of severe asthma, poorly controlled by antiasthmatic drugs, and complicated by a severe reflux that encompasses ulcerative esophagitis.

Cytoreductive surgery and intraperitoneal chemohyperthermia for peritoneal carcinomatosis arising from gastric cancer.

HYPOTHESIS: The most common cause of palliative resection and recurrence in gastric cancer is peritoneal seeding. This study evaluates the efficacy of intraperitoneal chemohyperthermia after cytoreductive surgery in patients with peritoneal carcinomatosis arising from gastric cancer. DESIGN: Prospective clinical trial. SETTING: Surgical department at a university academic hospital. PATIENTS: Forty-nine consecutive patients with peritoneal carcinomatosis treated between January 1, 1989, and February 29, 2000. INTERVENTIONS: All patients underwent intraperitoneal chemohyperthermia with mitomycin C (40-60 mg); 21 patients had previously undergone extensive cytoreductive surgery. MAIN OUTCOME MEASURES: Clinicopathologic factors that affect overall survival rates. RESULTS: With median follow-up of 99 months, overall median survival was 10.3 months. Two factors were significant independent predictors of survival by multivariate analysis: preoperative ascites (P =.04) and completeness of cancer resection (CCR) by cytoreductive surgery (P<.001). Median survival was 21.3 months for patients with CCR-0 (macroscopic complete resection) or CCR-1 (diameter of residual nodules <5 mm) and 6.1 months for patients with CCR-2 (diameter of residual nodules >5 mm) (P<.001). Four patients survived longer than 5 years. CONCLUSIONS: An aggressive management strategy combining intraperitoneal chemohyperthermia with cytoreductive surgery is effective for patients with peritoneal carcinomatosis arising from gastric cancer. In highly selected patients (good general status, resectable primary tumor, resectable peritoneal carcinomatosis), this therapy may result in long-term survival.

Non-supervised spatio-temporal analysis of interictal magnetic spikes: comparison with intracerebral recordings.

OBJECTIVE: Our main goal was to evaluate the accuracy of an original non-supervised spatio-temporal magnetoencephalography (MEG) localization method used to characterize interictal spikes generators. METHODS: MEG and stereotactic intracerebral recordings (stereo-electro-encephalographic exploration, SEEG) data were analyzed independently in 4 patients. MEG localizations were performed with and without anatomical constraints. RESULTS: We analyzed 1326 interictal spikes recorded using MEG. For each patient, 2-3 typical source patterns were described. These source configurations were compared with SEEG. SEEG findings and MEG spatio-temporal localization results were remarkably coherent in our 4 patients. Most of the MEG patterns were similar to interictal SEEG patterns from a spatio-temporal point of view. CONCLUSIONS: We were able to evaluate the usefulness of our non-invasive localization method. This approach described correctly the part of the epileptogenic network involved in the generation of interictal events. Our results demonstrate the potential of MEG in the non-invasive spatio-temporal characterization of generators of interictal spikes.

Seizures of temporal lobe epilepsy: identification of subtypes by coherence analysis using stereo-electro-encephalography.

OBJECTIVES: Two subtypes of temporal lobe epilepsy (TLE) according to the structures initially involved during seizures are currently recognized: medial TLE (MTLE) and lateral (or neocortical) TLE (LTLE). A few reports have suggested that the classification of TLE subtypes might be larger according to variations in the interactions between medial structures and the neocortex. In this study, we analyzed these interactions using coherence analysis of stereo-encephalographic (SEEG) signals during spontaneous seizures. METHODS: Twenty-seven patients with drug-resistant TLE, diagnosed from ictal SEEG recordings obtained during pre-surgical evaluation, were studied. Orthogonally implanted depth electrodes with multiple leads according to Talairach's method were used to sample medial and neocortical structures. Coherence analysis of ictal discharges was performed between two SEEG bipolar signals from adjacent leads located either in medial structures (amygdala and hippocampus) or in neocortical regions of the temporal lobe. A new algorithm, which was designed to reduce the bias inherent in coherence estimation, was used to compute the coherence. RESULTS: We were able to classify TLE seizures (TLES) into 4 distinct categories: (1) 'medial' TLES, characterized by medial onset with later involvement of the neocortex in the form of a 'phasic' discharge. High ictal coherence values were observed between medial structures; (2) 'medial-lateral' TLES which started in medial structures with a fast low-voltage discharge (FLVD) which rapidly affects the neocortex (< or = 3 s). High coherence values were observed between medial and lateral structures; (3) 'lateral-medial' TLES, which are different from medial-lateral TLES in that the FLVD starts in the lateral neocortex and involves the amygdala and/or hippocampus almost immediately after; (4) 'lateral' TLES: characterized by a neocortical onset, a delayed involvement of medial structures (when present), and high coherence values between neocortical structures. CONCLUSIONS: These results demonstrate the existence of numerous interactions between medial limbic structures and the neocortex during TLE seizures. Such findings could have implications for surgical strategies and the prognosis of epilepsy surgery, particularly when limited resection is indicated.