Outcome of emergency neurosurgery in patients with refractory and super-refractory status epilepticus: a systematic review and individual participant data meta-analysis.

Background: Refractory (RSE) and super-refractory status epilepticus (SRSE) are serious neurological conditions requiring aggressive management. Beyond anesthetic agents, there is a lack of evidence guiding management in these patients. This systematic review and individual participant data meta-analysis (IPDMA) seeks to evaluate and compare the currently available surgical techniques for the acute treatment of RSE and SRSE. Methods: A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Individual Participant Data (PRISMA-IPD). Only patients who underwent surgery while in RSE and SRSE were included. Descriptive statistics were used to compare various subgroups. Multivariable logistic regression models were constructed to identify predictors of status epilepticus (SE) cessation, long-term overall seizure freedom, and favorable functional outcome (i.e., modified Rankin score of 0-2) at last follow-up. Results: A total of 87 studies including 161 participants were included. Resective surgery tended to achieve better SE cessation rate (93.9%) compared to non-resective techniques (83.9%), but this did not reach significance (p = 0.071). Resective techniques were also more likely to achieve seizure freedom (69.1% vs. 34.4%, p = <0.0001). Older age at SE (OR = 1.384[1.046-1.832], p = 0.023) was associated with increased likelihood of SE cessation, while longer duration of SE (OR = 0.603[0.362-1.003], p = 0.051) and new-onset seizures (OR = 0.244[0.069-0.860], p = 0.028) were associated with lower likelihood of SE cessation, but this did not reach significance for SE duration. Only shorter duration of SE prior to surgery (OR = 1.675[1.168-2.404], p = 0.0060) and immediate termination of SE (OR = 3.736 [1.323-10.548], p = 0.014) were independently associated with long-term seizure status. Rates of favorable functional outcomes (mRS of 0-2) were comparable between resective (44.4%) and non-resective (44.1%) techniques, and no independent predictors of outcome were identified. Conclusion: Our findings suggest that emergency neurosurgery may be a safe and effective alternative in patients with RSE/SRSE and may be considered earlier during the disease course. However, the current literature is limited exclusively to small case series and case reports with high risk of publication bias. Larger clinical trials assessing long-term seizure and functional outcomes are warranted to establish robust management guidelines.

Cross-bispectrum connectivity of intracranial EEG: A novel approach to seizure onset zone localization.

Connectivity analyses of intracranial electroencephalography (iEEG) could guide surgical planning for epilepsy surgery by improving the delineation of the seizure onset zone. Traditional approaches fail to quantify important interactions between frequency components. To assess if effective connectivity based on cross-bispectrum -a measure of nonlinear multivariate cross-frequency coupling- can quantitatively identify generators of seizure activity, cross-bispectrum connectivity between channels was computed from iEEG recordings of 5 patients (34 seizures) with good postsurgical outcome. Personalized thresholds of 50% and 80% of the maximum coupling values were used to identify generating electrode channels. In all patients, outflow coupling between α (8-15 Hz) and ß (16-31 Hz) frequencies identified at least one electrode inside the resected seizure onset zone. With the 50% and 80% thresholds respectively, an average of 5 (44.7%; specificity = 82.6%) and 2 (22.5%; specificity = 99.0%) resected electrodes were correctly identified. Results show promise for the automatic identification of the seizure onset zone based on cross-bispectrum connectivity analysis.

Anterior Cingulate Epilepsy: A Review.

SUMMARY: In this review, the semiology, and characteristics of noninvasive investigations suggestive of anterior cingulate and anterior midcingulate epilepsy are detailed by the authors. The clinical presentation is representative of a recently recognized rostrocaudal gradient of functional connectivity with seizures of the anterior cingulate cortex manifesting emotional and interoceptive aura followed by a hyperkinetic or complex motor seizures. The few reports of anterior midcingulate epilepsy show a trend toward a higher proportion of sensory auras and premotor semiology. Ictal pouting, vocalizations, and, in particular, laughter are strong indicators of epilepsy arising or spreading to this region. Although scalp EEG was traditionally thought to provide little information, the data provided in this review demonstrate that most patients will have abnormalities over the frontal or frontotemporal regions. Frontotemporal abnormalities at least interictally provide valuable information regarding lateralization. The etiology of epilepsy arising from the anterior cingulate region seems to be most frequently secondary to focal cortical dysplasia (FCD), followed by neoplasms and vascular lesions, particularly cavernomas, although one cannot rule out a publication bias. Findings of nuclear medicine imaging is seldomly reported but both positron emission tomography and ictal single-photon computed tomography can identify the generator or the network often showing abnormalities extending to the frontal regions. The few available magnetoencephalography (MEG) studies reveal mixed results, sometimes providing false lateralization of the focus. Anterior cingulate epilepsy is difficult to recognize, but the features summarized in this review should prompt suspicion in clinical practice.

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

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

Clinical utility of intraoperative electrocorticography for epilepsy surgery: A systematic review and meta-analysis.

Despite the widespread use of intraoperative electrocorticography (iECoG) during resective epilepsy surgery, there are conflicting data on its overall efficacy and inability to predict benefit per pathology. Given the heterogeneity of iECoG use in resective epilepsy surgery, it is important to assess the utility of interictal-based iECoG. This individual patient data (IPD) meta-analysis seeks to identify the benefit of iECoG during resective epilepsy surgery in achieving seizure freedom for various pathologies. Embase, Scopus, and PubMed were searched from inception to January 31, 2021 using the following terms: "ecog", "electrocorticography", and "epilepsy". Articles were included if they reported seizure freedom at ≥12-month follow-up in cohorts with and without iECoG for epilepsy surgery. Non-English articles, noncomparative iECoG cohorts, and studies with <10% iECoG use were excluded. This meta-analysis followed the PRISMA 2020 guidelines. The primary outcome was seizure freedom at last follow-up and time to seizure recurrence, if applicable. Forest plots with random effects modeling assessed the relationship between iECoG use and seizure freedom. Cox regression of IPD was performed to identify predictors of longer duration of seizure freedom. Kaplan-Meier curves with log-rank test were created to visualize differences in time to seizure recurrence. Of 7504 articles identified, 18 were included for study-level analysis. iECoG was not associated with higher seizure freedom at the study level (relative risk = 1.09, 95% confidence interval [CI] = 0.96-1.23, p = .19, I2  = 64%), but on IPD (n = 7 studies, 231 patients) iECoG use was independently associated with more favorable seizure outcomes (hazard ratio = 0.47, 95% CI = .23-.95, p = .037). In Kaplan-Meier analysis of specific pathologies, iECoG use was significantly associated with longer seizure freedom only for focal cortical dysplasia (FCD; p < .001) etiology. Number needed to treat for iECoG was 8.8, and for iECoG in FCD it was 4.7. We show iECoG seizure freedom is not achieved uniformly across centers. iECoG is particularly beneficial for FCD etiology in improving seizure freedom.

Predictors of outcomes after surgery for medically intractable insular epilepsy: A systematic review and individual participant data meta-analysis.

Insular epilepsy (IE) is an increasingly recognized cause of drug-resistant epilepsy amenable to surgery. However, concerns of suboptimal seizure control and permanent neurological morbidity hamper widespread adoption of surgery for IE. We performed a systematic review and individual participant data meta-analysis to determine the efficacy and safety profile of surgery for IE and identify predictors of outcomes. Of 2483 unique citations, 24 retrospective studies reporting on 312 participants were eligible for inclusion. The median follow-up duration was 2.58 years (range, 0-17 years), and 206 (66.7%) patients were seizure-free at last follow-up. Younger age at surgery (≤18 years; HR = 1.70, 95% CI = 1.09-2.66, P = .022) and invasive EEG monitoring (HR = 1.97, 95% CI = 1.04-3.74, P = .039) were significantly associated with shorter time to seizure recurrence. Performing MR-guided laser ablation or radiofrequency ablation instead of open resection (OR = 2.05, 95% CI = 1.08-3.89, P = .028) was independently associated with suboptimal or poor seizure outcome (Engel II-IV) at last follow-up. Postoperative neurological complications occurred in 42.5% of patients, most commonly motor deficits (29.9%). Permanent neurological complications occurred in 7.8% of surgeries, including 5% and 1.4% rate of permanent motor deficits and dysphasia, respectively. Resection of the frontal operculum was independently associated with greater odds of motor deficits (OR = 2.75, 95% CI = 1.46-5.15, P = .002). Dominant-hemisphere resections were independently associated with dysphasia (OR = 13.09, 95% CI = 2.22-77.14, P = .005) albeit none of the observed language deficits were permanent. Surgery for IE is associated with a good efficacy/safety profile. Most patients experience seizure freedom, and neurological deficits are predominantly transient. Pediatric patients and those requiring invasive monitoring or undergoing stereotactic ablation procedures experience lower rates of seizure freedom. Transgression of the frontal operculum should be avoided if it is not deemed part of the epileptogenic zone. Well-selected candidates undergoing dominant-hemisphere resection are more likely to exhibit transient language deficits; however, the risk of permanent deficit is very low.

Sensorimotor outcomes after resection for perirolandic drug-resistant epilepsy: a systematic review and individual patient data meta-analysis.

OBJECTIVE: The prevalence of long-term postoperative sensorimotor deficits in children undergoing perirolandic resective epilepsy surgery is unclear. The risk of developing these deficits must be weighed against the potential reduction in seizure frequency after surgery. In this study, the authors investigated the prevalence of sensorimotor deficits after resective surgery at ≥ 1 year postoperatively. METHODS: A systematic review and individual patient data meta-analysis was conducted using PubMed, Embase, and Scopus databases. Subgroups of patients were identified and categorized according to their outcomes as follows: group A patients were denoted as seizure free with no postoperative sensorimotor deficits; group B patients experienced seizure recurrence with no deficit; group C patients were seizure free with deficits; and group D patients were not seizure free and with deficits. Rates of sensory deficits were examined in patients undergoing postcentral gyrus resection, and rates of motor deficits were aggregated in patients undergoing precentral gyrus resection. RESULTS: Of 797 articles resulting from the database searches, 6 articles including 164 pediatric patients at a mean age of 7.7 ± 5.2 years with resection for drug-resistant perirolandic epilepsy were included in the study. Seizure freedom was observed in 118 (72.9%) patients at a mean follow-up of 3.4 ± 1.8 years. In total, 109 (66.5%) patients did not develop sensorimotor deficits at last follow-up, while 55 (33.5%) had permanent deficits. Ten (14.3%) of 70 patients with postcentral gyrus resection had permanent sensory deficits. Of the postcentral gyrus resection patients, 41 (58.6%) patients were included in group A, 19 (27.1%) in group B, 7 (10.0%) in group C, and 3 (4.3%) in group D. Forty (37.7%) of 106 patients with precentral resections had permanent motor deficits. Of the precentral gyrus resection patients, 50 (47.2%) patients were in group A, 16 (15.1%) in group B, 24 (22.6%) in group C, and 16 (15.1%) in group D. Patients without focal cortical dysplasia were more likely to have permanent motor deficits relative to those with focal cortical dysplasia in the precentral surgery cohort (p = 0.02). CONCLUSIONS: In total, 58.6% of patients were seizure free without deficit, 27.1% were not seizure free and without deficit, 10.0% were seizure free but with deficit, and 4.3% were not seizure free and with deficit. Future studies with functional and quality-of-life data, particularly for patients who experience seizure recurrence with no deficits (as in group B in the present study) and those who are seizure free with deficits (as in group C) after treatment, are necessary to guide surgical decision-making.

Neuroimaging of Epilepsy.

PURPOSE OF REVIEW: This article provides an overview of imaging modalities, important imaging pathologies, and the role each imaging modality can play in the diagnosis, evaluation, and treatment of epilepsy, including epilepsy surgery. RECENT FINDINGS: The Harmonized Neuroimaging of Epilepsy Structural Sequences (HARNESS-MRI) protocol was proposed to standardize MRI imaging for all patients with seizures. The role of 7-Tesla MRI in finding previously occult epileptogenic lesions is under investigation, and the technique is increasingly used. Developing MRI postprocessing techniques can increase the sensitivity of MRI. Improvements in functional imaging techniques such as EEG-functional MRI (fMRI) and magnetic source imaging provide complementary methods of identifying seizure foci. New epileptogenic pathologies such as multinodular and vacuolating neuronal tumors (MVNT) are being discovered, and the importance of others, such as encephaloceles, is better appreciated. SUMMARY: Brain imaging is a critical component of the diagnosis and evaluation of patients with epilepsy. Structural imaging modalities such as MRI and CT allow for the identification of a wide variety of potentially epileptogenic lesions. For patients with drug-resistant epilepsy under consideration for resective surgery, both structural and functional neuroimaging may be needed for focus identification and surgical planning for preservation of neurologic function.

Validity and reliability of global ratings of satisfaction with epilepsy surgery.

OBJECTIVE: We aimed to assess the reliability and validity of single-item global ratings (GR) of satisfaction with epilepsy surgery. METHODS: We recruited 240 patients from four centers in Canada and Sweden who underwent epilepsy surgery ≥1 year earlier. Participants completed a validated questionnaire on satisfaction with epilepsy surgery (the ESSQ-19), plus a single-item GR of satisfaction with epilepsy surgery twice, 4-6 weeks apart. They also completed validated questionnaires on quality of life, depression, health state utilities, epilepsy severity and disability, medical treatment satisfaction and social desirability. Test-retest reliability of the GR was assessed with the intra-class correlation coefficient (ICC). Construct and criterion validity were examined with polyserial correlations between the GR measure of satisfaction and validated questionnaires and with the ESSQ-19 summary score. Non-parametric rank tests evaluated levels of satisfaction, and ROC analysis assessed the ability of GRs to distinguish among clinically different patient groups. RESULTS: Median age and time since surgery were 42 years (IQR 32-54) and 5 years (IQR 2-8), respectively. The GR demonstrated good to excellent test-retest reliability (ICC = 0.76; 95% CI 0.67-0.84) and criterion validity (0.85; 95% CI 0.81-0.89), and moderate correlations in the expected direction with instruments assessing quality of life (0.59; 95% CI 0.51-0.63), health utilities (0.55; 95% CI 0.45-0.65), disability (-0.51; 95% CI -0.41, -0.61), depression (-0.48; 95% CI -0.38, -0.58), and epilepsy severity (-0.48; 95% CI -0.38, -0.58). As expected, correlations were lower for social desirability (0.40; 95% CI 0.28-0.52) and medical treatment satisfaction (0.33; 95% CI 0.21-0.45). The GR distinguished participants who were seizure-free (AUC 0.75; 95% CI 0.67-0.82), depressed (AUC 0.75; 95% CI 0.67-0.83), and self-rated as having more severe epilepsy (AUC 0.78; 95% CI 0.71-0.85) and being more disabled (AUC 0.82; 95% CI 0.74-0.90). SIGNIFICANCE: The GR of epilepsy surgery satisfaction showed good measurement properties, distinguished among clinically different patient groups, and appears well-suited for use in clinical practice and research.

Predicting postoperative epilepsy surgery satisfaction in adults using the 19-item Epilepsy Surgery Satisfaction Questionnaire and machine learning.

OBJECTIVE: The 19-item Epilepsy Surgery Satisfaction Questionnaire (ESSQ-19) is a validated and reliable post hoc means of assessing patient satisfaction with epilepsy surgery. Prediction models building on these data can be used to counsel patients. METHODS: The ESSQ-19 was derived and validated on 229 patients recruited from Canada and Sweden. We isolated 201 (88%) patients with complete clinical data for this analysis. These patients were adults (≥18 years old) who underwent epilepsy surgery 1 year or more prior to answering the questionnaire. We extracted each patient's ESSQ-19 score (scale is 0-100; 100 represents complete satisfaction) and relevant clinical variables that were standardized prior to the analysis. We used machine learning (linear kernel support vector regression [SVR]) to predict satisfaction and assessed performance using the R2 calculated following threefold cross-validation. Model parameters were ranked to infer the importance of each clinical variable to overall satisfaction with epilepsy surgery. RESULTS: Median age was 41 years (interquartile range [IQR] = 32-53), and 116 (57%) were female. Median ESSQ-19 global score was 68 (IQR = 59-75), and median time from surgery was 5.4 years (IQR = 2.0-8.9). Linear kernel SVR performed well following threefold cross-validation, with an R2 of .44 (95% confidence interval = .36-.52). Increasing satisfaction was associated with postoperative self-perceived quality of life, seizure freedom, and reductions in antiseizure medications. Self-perceived epilepsy disability, age, and increasing frequency of seizures that impair awareness were associated with reduced satisfaction. SIGNIFICANCE: Machine learning applied postoperatively to the ESSQ-19 can be used to predict surgical satisfaction. This algorithm, once externally validated, can be used in clinical settings by fixing immutable clinical characteristics and adjusting hypothesized postoperative variables, to counsel patients at an individual level on how satisfied they will be with differing surgical outcomes.

Multispectral diffuse reflectance can discriminate blood vessels and bleeding during neurosurgery based on low-frequency hemodynamics.

SIGNIFICANCE: The practicality of optical methods detecting tissue optical contrast (absorption, elastic and inelastic scattering, fluorescence) for surgical guidance is limited by interferences from blood pooling and the resulting partial or complete inability to interrogate cortex and blood vessels. AIM: A multispectral diffuse reflectance technique was developed for intraoperative brain imaging of hemodynamic activity to automatically discriminate blood vessels, cortex, and bleeding at the brain surface. APPROACH: A manual segmentation of blood pooling, cortex, and vessels allowed the identification of a frequency range in hemoglobin concentration variations associated with high optical signal in blood vessels and cortex but not in bleeding. Reflectance spectra were then used to automatically segment areas with and without hemodynamic activity as well as to discriminate blood from cortical areas. RESULTS: The frequency range associated with low-frequency hemodynamics and respiratory rate (0.03 to 0.3 Hz) exhibits the largest differences in signal amplitudes for bleeding, blood vessels, and cortex. A segmentation technique based on simulated reflectance spectra initially allowed discrimination of blood (bleeding and vessels) from cortical tissue. Then, a threshold applied to the low-frequency components from deoxyhemoglobin allowed the segmentation of bleeding from vessels. A study on the minimum acquisition time needed to discriminate all three components determined that ∼25 s was necessary to detect changes in the low-frequency range. Other frequency ranges such as heartbeat (1 to 1.7 Hz) can be used to reduce the acquisition time to few seconds but would necessitate optimizing instrumentation to ensure larger signal-to-noise ratios are achieved. CONCLUSIONS: A method based on multispectral reflectance signals and low-frequency hemoglobin concentration changes can be used to distinguish bleeding, blood vessels, and cortex. This could be integrated into fiber optic probes to enhance signal specificity by providing users an indication of whether measurements are corrupted by blood pooling, an important confounding factor in biomedical optics applied to surgery.

Development and validation of the Epilepsy Surgery Satisfaction Questionnaire (ESSQ-19).

OBJECTIVE: No validated tools exist to assess satisfaction with epilepsy surgery. We aimed to develop and validate a new measure of patient satisfaction with epilepsy surgery, the 19-item Epilepsy Surgery Satisfaction Questionnaire (ESSQ-19). METHODS: An initial 31-item measure was developed based on literature review, patient focus groups, thematic analysis, and Delphi panels. The questionnaire was administered twice, 4-6 weeks apart, to 229 adults (≥18 years old) who underwent epilepsy surgery ≥1 year earlier, at three centers in Canada and one in Sweden. Participants also completed seven validated questionnaires to assess construct validity. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) assessed the factorial structure of the questionnaire. Cronbach alpha and intraclass correlation coefficients (ICCs) assessed the internal consistency and test-retest reliability of the ESSQ-19. Spearman and polyserial correlations assessed construct validity. RESULTS: Median age of participants and time since surgery were 42 years (interquartile range [IQR] = 32-54) and 5 years (IQR = 2-8.75), respectively. EFA and CFA yielded 18 items that segregated into four domains (mean score [SD]), namely, seizure control (76.4 [25]), psychosocial functioning (67.3 [26]), surgical complications (84 [22]), and recovery from surgery (73 [24]), one global satisfaction item, and a summary global score (74 [21]). The domain and summary scores demonstrated good to excellent internal reliability (Cronbach ⍺ range = .84-.95) and test-retest reliability (ICC range = 0.71-0.85). Construct validity was supported by predicted correlations with other instruments. SIGNIFICANCE: The ESSQ-19 is a new, valid, and reliable measure of patient satisfaction with epilepsy surgery that can be used in clinical and research settings.

Large-Scale Desynchronization During Interictal Epileptic Discharges Recorded With Intracranial EEG.

It is increasingly recognized that deep understanding of epileptic seizures requires both localizing and characterizing the functional network of the region where they are initiated, i. e., the epileptic focus. Previous investigations of the epileptogenic focus' functional connectivity have yielded contrasting results, reporting both pathological increases and decreases during resting periods and seizures. In this study, we shifted paradigm to investigate the time course of connectivity in relation to interictal epileptiform discharges. We recruited 35 epileptic patients undergoing intracranial EEG (iEEG) investigation as part of their presurgical evaluation. For each patient, 50 interictal epileptic discharges (IEDs) were marked and iEEG signals were epoched around those markers. Signals were narrow-band filtered and time resolved phase-locking values were computed to track the dynamics of functional connectivity during IEDs. Results show that IEDs are associated with a transient decrease in global functional connectivity, time-locked to the peak of the discharge and specific to the high range of the gamma frequency band. Disruption of the long-range connectivity between the epileptic focus and other brain areas might be an important process for the generation of epileptic activity. Transient desynchronization could be a potential biomarker of the epileptogenic focus since 1) the functional connectivity involving the focus decreases significantly more than the connectivity outside the focus and 2) patients with good surgical outcome appear to have a significantly more disconnected focus than patients with bad outcomes.

Decision-making impairments following insular and medial temporal lobe resection for drug-resistant epilepsy.

Besides the prefrontal cortex, the insula and medial structures of the temporal lobe are thought to be involved in risky decision-making. However, their respective contributions to decision processes remain unclear due to the lack of studies involving patients with isolated insular damage. We assessed adult patients who underwent resection of the insula (n = 13) or of the anterior temporal lobe (including medial structures) (n = 13) as part of their epilepsy surgery, and a group of healthy volunteers (n = 20), on the Iowa Gambling Task (IGT) and on the Cups Task. Groups were matched on sociodemographic, estimated-IQ and surgery-related factors. On the IGT, patients with temporal lobe resection performed significantly worse than both the insular and healthy control groups, as they failed to learn which decks were advantageous on the long-term. On the Cups Task, the insular and temporal groups both showed impaired sensitivity to expected value in the loss domain, when compared with healthy controls. These findings provide clinical evidence that the insula and mesiotemporal structures are specifically involved in risky decision-making when facing a potential loss, and that temporal structures are also involved in learning the association between behavior and consequences in the long-term.

Social information processing following resection of the insular cortex.

The insula has been implicated in social cognition and empathy in several neuroimaging paradigms. Impairments in social information processing, including specific deficits in disgust recognition, have been described following isolated insular damage, although the evidence remains limited to a few case studies. The present study examines social cognition and empathy in a group of fifteen patients for whom the insula was removed as part of their epilepsy surgery. These patients were compared to a lesion-control group of 15 epileptic patients who had a surgery in the anterior temporal lobe that spared the insula, and to 20 healthy volunteers matched on age, sex, and education. Participants were assessed on an Emotion Recognition Task (ERT), the Reading the Mind in the Eyes test, and a self-administered empathy questionnaire. Patients who underwent insular resection showed poorer ability to recognize facial expressions of emotions and had lower scores of perspective taking on the empathy questionnaire than healthy controls. Using results from healthy controls as normative data, emotion recognition deficits were more frequent in insular patients than in both other groups. Specific emotion analyses revealed impairments in fear recognition in both groups of patients, whereas happiness and surprise recognition was only impaired in patients with insular resection. There was no evidence for a deficit in disgust recognition. The findings suggest that unilateral damage to the operculo-insular region may be associated with subtle impairments in emotion recognition, and provide further clinical evidence of a role of the insula in empathic processes. However, the description of 15 consecutive cases of insula-damaged patients with no specific deficit in disgust recognition seriously challenges the assumptions, based on previous case reports, that the insula is specifically involved in disgust processing.

Neuropsychological performance before and after partial or complete insulectomy in patients with epilepsy.

Resection of the insular cortex is becoming more frequent as it is increasingly recognized that a nonnegligible proportion of surgical candidates with drug-resistant epilepsy have an epileptogenic zone that involves the insula. In the last decades, however, the insula has been proposed to be involved in several neuropsychological functions, and there is a lack of documentation on whether partial or complete insulectomy results in permanent cognitive impairments in this clinical population. In this study, we conducted standard preoperative and postoperative neuropsychological assessments in 18 patients undergoing epilepsy surgery that included the removal of the insula in the right (n=13) or the left (n=5) hemisphere. Postoperative testing was conducted at least five months after surgery. Cognitive impairments were common and heterogeneous prior to surgery, with language and verbal memory impairments being especially frequent among patients in whom epileptic seizures originated from the left hemisphere. After surgery, declines and improvements occurred on a variety of outcomes, although new deficits were relatively infrequent among patients who had obtained normal performance at baseline. Statistical comparisons between preoperative and postoperative assessments revealed significant deterioration of only one outcome - the color naming condition of the Stroop test - which relies on oro-motor speed and lexical access. These findings suggest that partial or complete resection of the insular cortex in patients with drug-refractory epilepsy can be conducted without major permanent neuropsychological impairments in a vast majority of patients. However, small decrements in specific cognitive functions can be expected, which should also be taken into account when considering the surgical option in this clinical population.

Prophylactic anticonvulsants for gliomas: a seven-year retrospective analysis.

BACKGROUND: The American Academy of Neurology (AAN) does not recommend routine use of prophylactic antiepileptic drugs (pAEDs) in patients with newly diagnosed brain tumors. If used in the perioperative setting, discontinuation is suggested after the first postoperative week. It is unclear whether such recommendations are followed. Our objective was to compare our perioperative and long-term pAED use in glioma patients with AAN practice parameters. METHODS: Retrospective chart review was performed on 578 glioma patients from 2006 to 2013. Seizures and AED use were assessed at surgery, 3 months postoperatively and death, last visit or 16 months postoperatively. Patients were divided into three groups at surgery: seizure-free with pAED, seizure-free without pAED, and seizure patients. Long-term pAED use was defined as continued use at 3 months postsurgery without seizures. pAEDs efficacy, factors influencing its use, and survival were examined. RESULTS: Out of 578 patients identified, 330 (57.1%) were seizure-naïve preoperatively. There were no significant differences in age, histology, tumor location or resection status between seizure-free populations with and without prophylaxis. Of 330 seizure-naïve patients, 205 (62.1%) received pAEDs at surgery. Ninety-six (46.9%) of those patients were still on pAEDs 3 months postsurgery (median use = 58 days). Rate of long-term prophylaxis use decreased by 13.5% over 6 years (70.3% in 2006; 56.8% in 2012). Phenytoin was preferred in 2006 (98.2%) with increasing use of levetiracetam over 6 years (44.6% in 2012). The only predictive factor for pAED use was complete resection (P = .0069). First seizure prevalence was similar in both seizure-free populations (P = .91). The seizure population had more men (P = .007), younger patients (P < .0001), lower-grade gliomas (P = .0003) and survived longer (P = .001) compared with seizure-free populations. CONCLUSIONS: In our center, long-term prophylactic AED use is high, deviating from current AAN Guidelines. Corrective measures are warranted.

Levetiracetam efficacy in refractory partial-onset seizures, especially after failed epilepsy surgery.

PURPOSE: We conducted a retrospective study to evaluate the efficacy of levetiracetam as adjunctive therapy in patients with localization-related epilepsy, and specifically in the subset of patients for whom epilepsy surgery failed. METHODS: Eighty-two patients with uncontrolled partial-onset seizures treated with levetiracetam were identified; epilepsy surgery had failed for 21 (25.6%; group I), and 61 (74.4%) had no prior surgery (group II). Group I and group II patients were comparable in age (mean, 40.7 vs. 41.5 years) and age at seizure onset (mean, 14.4 vs. 18.2 years). Patients who had >/=50% reduction in seizure frequency were considered responders; the remaining patients were considered nonresponders. RESULTS: In patients (group I) for whom surgery had failed, responder rate was 76.1% (16 of 21), including 10 (47.6%) patients who became seizure free. In nonsurgical patients (group II), responder rate was 34.3% (21 of 61), including nine (14.7%) patients who became seizure free. In group I, 11 (91.6%) of 12 temporal resection patients were responders, of whom eight were seizure free; of the remaining nine operated (extratemporal) patients, five (55.5%) were responders, and two were seizure free. In three responders, all in group I, a severe, delayed psychotic syndrome developed 4 to 9 months after levetiracetam introduction, leading to its discontinuation. CONCLUSIONS: These findings suggest that adjunctive levetiracetam therapy should be considered early after failed epilepsy surgery, especially after temporal resection, and may have implications for its use before surgical intervention. Patients should be under close psychiatric observation in this clinical setting.