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The Socialist Republic of Vietnam is a developing country with an estimated population of 96.2 million as of 2019. The prevalence rate of epilepsy is between 4.4 and 14 per 1000 population. The care of epileptic patients in Vietnam is suboptimal for many reasons: insufficient resources, poor infrastructure, lack of education (to both patients and physicians), and inadequate offer of medical and surgical treatment options for epilepsy.

OBJECTIVEOperculoinsular cortectomy (also termed operculoinsulectomy) is increasingly recognized as a therapeutic option for perisylvian refractory epilepsy. However, most neurosurgeons are reluctant to perform the technique because of previously experienced or feared neurological complications. The goal of this study was to quantify the incidence of basic neurological complications (loss of primary nonneuropsychological functions) associated with operculoinsular cortectomies for refractory epilepsy, and to identify factors predicting these complications.METHODSClinical, imaging, and surgical data of all patients investigated and surgically treated by our team for refractory epilepsy requiring an operculoinsular cortectomy were retrospectively reviewed. Patients with tumors and encephalitis were excluded. Logistic regression analysis was used for uni- and multivariate statistical analyses.RESULTSForty-four operculoinsular cortectomies were performed in 43 patients. Although postoperative neurological deficits were frequent (54.5% of procedures), only 3 procedures were associated with a permanent significant neurological deficit. Out of the 3 permanent deficits, only 1 (2.3%; a sensorimotor hemisyndrome) was related to the technique of operculoinsular cortectomy (injury to a middle cerebral artery branch), while the other 2 (arm hypoesthesia and hemianopia) were attributed to cortical resection beyond the operculoinsular area. With multivariate analysis, a postoperative neurological deficit was associated with preoperative insular hypometabolism on PET scan. Postoperative motor deficit (29.6% of procedures) was correlated with fewer years of neurosurgical experience and frontal operculectomies, but not with corona radiata ischemic lesions. Ischemic lesions in the posterior two-thirds of the corona radiata (40.9% of procedures) were associated with parietal operculectomies, but not with posterior insulectomies.CONCLUSIONSOperculoinsular cortectomy for refractory epilepsy is a relatively safe therapeutic option but temporary neurological deficits after surgery are frequent. This study highlights the role of frontal/parietal opercula resections in postoperative complications. Corona radiata ischemic lesions are not clearly related to motor deficits. There were no obvious permanent neurological consequences of losing a part of an epileptic insula, including on the dominant side for language. A low complication rate can be achieved if the following conditions are met: 1) microsurgical technique is applied to spare cortical branches of the middle cerebral artery; 2) the resection of an opercula is done only if the opercula is part of the epileptic focus; and 3) the neurosurgeon involved has proper training and experience.

OBJECTIVEPatients with refractory epilepsy of operculoinsular origin are often denied potentially effective surgical treatment with operculoinsular cortectomy (also termed operculoinsulectomy) because of feared complications and the paucity of surgical series with a significant number of cases documenting seizure control outcome. The goal of this study was to document seizure control outcome after operculoinsular cortectomy in a group of patients investigated and treated by an epilepsy team with 20 years of experience with this specific technique.METHODSClinical, imaging, surgical, and seizure control outcome data of all patients who underwent surgery for refractory epilepsy requiring an operculoinsular cortectomy were retrospectively reviewed. Tumors and progressive encephalitis cases were excluded. Descriptive and uni- and multivariate analyses were done to determine seizure control outcome and predictors.RESULTSForty-three patients with 44 operculoinsular cortectomies were studied. Kaplan-Meier estimates of complete seizure freedom (first seizure recurrence excluding auras) for years 0.5, 1, 2, and 5 were 70.2%, 70.2%, 65.0%, and 65.0%, respectively. With patients with more than 1 year of follow-up, seizure control outcome Engel class I was achieved in 76.9% (mean follow-up duration 5.8 years; range 1.25–20 years). With multivariate analysis, unfavorable seizure outcome predictors were frontal lobe–like seizure semiology, shorter duration of epilepsy, and the use of intracranial electrodes for invasive monitoring. Suspected causes of recurrent seizures were sparing of the language cortex part of the focus, subtotal resection of cortical dysplasia/polymicrogyria, bilateral epilepsy, and residual epileptic cortex with normal preoperative MRI studies (insula, frontal lobe, posterior parieto-temporal, orbitofrontal).CONCLUSIONSThe surgical treatment of operculoinsular refractory epilepsy is as effective as epilepsy surgeries in other brain areas. These patients should be referred to centers with appropriate experience. A frontal lobe–like seizure semiology should command more sampling with invasive monitoring. Recordings with intracranial electrodes are not always required if the noninvasive investigation is conclusive. The complete resection of the epileptic zone is crucial to achieve good seizure control outcome.

Background: We aimed to evaluate heart rate variability (HRV) changes in insulo-opercular epilepsy (IOE) and after insulo-opercular surgery. Methods: We analyzed 5-min resting HRV of IOE patients before and after surgery. Patients’ SUDEP-7 risk inventory scores were also calculated. Results were compared with age- and sex-matched patients with temporal lobe epilepsy (TLE) and healthy individuals. Results: There were no differences in HRV measurements between IOE, TLE, and healthy control groups (and within each IOE group and TLE group) in preoperative and postoperative periods. In IOE patients, the SUDEP-7 score was positively correlated with pNN50 (percentage of successive RR intervals that differ by more than 50 ms) (p = 0.008) and RMSSD (root mean square of successive RR interval differences) (p = 0.019). We stratified IOE patients into those whose preoperative RMSSD values were below (Group 1a = 7) versus above (Group 1b = 9) a cut-off threshold of 31 ms (median value of a healthy population from a previous study). In group 1a, all HRV values significantly increased after surgery. In group 1b, time-domain parameters significantly decreased postoperatively. Conclusions: Our results suggest that in IOE, HRV may be either decreased in parasympathetic tone or increased globally in both sympathetic and parasympathetic tones. We found no evidence that insulo-opercular surgeries lead to major autonomic dysfunction when a good seizure outcome is reached. The increase in parasympathetic tone observed preoperatively may be of clinical concern, as it was positively correlated with the SUDEP-7 score.

Background Operculoinsular cortectomy is increasingly recognized as a therapeutic avenue for perisylvian refractory epilepsy. However, most neurosurgeons are reluctant to perform this type of procedure because of feared neurological complications, especially in the language-dominant hemisphere, as the insula is involved in speech and language processes. The goal of this retrospective study is to quantify the incidence and types of speech and language deficits associated with operculoinsulectomies in the dominant hemisphere for language, and to identify factors associated with these complications. Methods Clinical, imaging, and surgical data of all patients who had an operculoinsulectomy for refractory epilepsy at our center between 1998 and 2018 were reviewed. Language lateralization was determined by functional magnetic resonance imaging (fMRI) and/or Wada test. Speech and language assessments were carried out by neurosurgeons, neurologists, neuropsychologists and/or speech language pathologists, before surgery, during the first week after surgery, and at least 6 months after surgery. Results Amongst 44 operculoinsulectomies, 13 were performed in the language-dominant hemisphere. 46% of these patients presented with transient aphasia post-surgery. However, a few months later, the patients’ performances on language assessments were not statistically different from before surgery, thus suggesting a complete recovery of speech and language functions. Conclusion Temporary aphasias after operculoinsulectomy for refractory epilepsy in the language-dominant hemisphere are frequent, but eventually subside. Potential mechanisms underlying this recovery are discussed.

Introducción: Los pacientes con convulsiones intratables que no son candidatos para la cirugía de resección focal están indicados para un procedimiento quirúrgico paliativo, la callosotomía. Este procedimiento se basa en la hipótesis de que el cuerpo calloso es una importante vía para la propagación interhemisférica de la actividad epiléptica y, para la epilepsia resistente a fármacos. Presenta relativamente baja morbilidad permanente y una eficacia en el control de las convulsiones. Sobre la base de la literatura, la callostomía mejora la calidad de vida de los pacientes que tiene la indicación para realizar este procedimiento, ya que permite reducir la frecuencia de las crisis, ya sean tónica o átona, tónico-clónicas, ausencia o lóbulo frontal crisis parciales complejas. Objetivo: El objetivo de esta revisión de la literatura es discutir los detalles técnicos, modalidades, riesgos, complicaciones, resultados y de pronóstico de callosotomía basado en la revisión crítica de la literatura y la experiencia de los autores. Casuística y Métodos: Se realizó la consulta bibliográfica, utilizando la base de datos MEDLINE, LILACS, SciELO, que utiliza el lenguaje como criterios de selección, la elección de los artículos recientes preferiblemente en portugués, español o Inglés, con el año de publicación superior a 2000. Conclusión: De acuerdo con la experiencia y las referencias del autor, callosotomía es un procedimiento seguro cuando indicado para casos seleccionados y la tasa de éxito es proporcional a la extensión de la resección del cuerpo calloso. A mayor resección puede reducir la frecuencia de las crisis, sin embargo, la morbilidad puede ser también mayor. No hay ningún estudio que compara la estimulación del nervio vago frente a frente callosotomía VNS más callososotomy, lo que sería la futura necesaria para una importante fuente de datos sobre este tema.

Objectives: With the current trend of aging of the population, neurosurgeons will be more and more confronted to surgical decision-making involving the elderly. Faced with this increasing demand and frailty of aged patients, a better understanding on the post-operative outcome of this growing population is warranted. The objective of the present study is to assess the post-operative outcome in regard of complications of elderly patients undergoing a craniotomy. Patients and methods: The files of consecutive patients aged 80 years old and more who underwent a craniotomy at a single institution were retrospectively reviewed. Data on demographics, surgical indication, length of surgery, operative blood loss, urgency of surgery, comorbidities using the Elixhauser comorbidity index and post-operative complications were gathered. We performed a multivariate analysis in search of risk factors for post-operative complications. Results: A total of 53 patients were included in the study. The mean age of all patients was 84 years old with the main indication for surgery being subdural hematoma. The overall complication rate was 62%, with 34% of patients suffering from a major complication and 47% from a minor complication. The mean Elixhauser comorbidity index, operative time and operative blood loss were similar to those reported in adult craniotomy series. None of the studied variables were statistically associated with the occurrence of complications in the multivariate analysis. Conclusion: Patients 80 years-old and more were found to harbour a high complication rate following craniotomy when compared to literature. Our study suggests increasing age itself remains an important risk factor for postoperative complications. Keywords: Comorbidity, Complication, Craniotomy, Elderly, Outcome

Background Epilepsy surgery is likely underutilised. Our goal was to study the utilisation of epilepsy surgery in the general population, using Canada as a model of a high-income country with universal medical coverage. Methods We systematically identified all epilepsy surgery centres in Canada that were active in 2015. A standardised questionnaire was completed by every centre. Descriptive statistics are reported. Comparisons were made to a 2003 survey of paediatric epilepsy surgery. Results Twelve adult and 11 paediatric epilepsy surgery centres were identified, performing a total of 456 and 206 surgical procedures, respectively, in 2015. Adult centres were in only six of 10 provinces; paediatric centres were in seven. Two thirds of adult centres and one third of paediatric centres were high-volume centres. Per capita volume per province varied between 7.0 and 20.5 therapeutic surgeries per million adult residents, and between 7.8 and 48.4 per million paediatric residents. Temporal lobe resections accounted for 59.8% and 33.5% of all adult and paediatric treatments, respectively. Eleven adult and nine paediatric centres possessed facilities to carry out intracranial investigations but only six and two, respectively, performed at least six intracranial implantations in 2015. There was a modest increase in the per capita number of paediatric surgeries between 2003 and 2015. Conclusions There is dramatic inter-centre and interprovincial variability in the epilepsy services available and the type of surgical interventions performed with significant gaps identified in some regions. Our findings are pivotal for the future optimisation of care offered to this vulnerable patient population.

Introduction: To date, clinical trials of deep brain stimulation (DBS) for refractory chronic pain have yielded unsatisfying results. Recent evidence suggests that the posterior insula may represent a promising DBS target for this indication. Methods: We present a narrative review highlighting the theoretical basis of posterior insula DBS in patients with chronic pain. Results: Neuroanatomical studies identified the posterior insula as an important cortical relay center for pain and interoception. Intracranial neuronal recordings showed that the earliest response to painful laser stimulation occurs in the posterior insula. The posterior insula is one of the only regions in the brain whose low-frequency electrical stimulation can elicit painful sensations. Most chronic pain syndromes, such as fibromyalgia, had abnormal functional connectivity of the posterior insula on functional imaging. Finally, preliminary results indicated that high-frequency electrical stimulation of the posterior insula can acutely increase pain thresholds. Conclusion: In light of the converging evidence from neuroanatomical, brain lesion, neuroimaging, and intracranial recording and stimulation as well as non-invasive stimulation studies, it appears that the insula is a critical hub for central integration and processing of painful stimuli, whose high-frequency electrical stimulation has the potential to relieve patients from the sensory and affective burden of chronic pain.

BACKGROUND Facial palsy is a rare, unexpected complication of temporal lobectomy (TL) for intractable epilepsy. Even without direct manipulation, the facial nerve fibers may be at risk of injury during supratentorial surgery, including TL. OBSERVATIONS The authors presented two cases of facial palsy after unremarkable TL. In the first case, the palsy appeared in a delayed fashion and completely resolved within weeks. In the second case, facial nerve dysfunction was observed immediately after surgery, followed by progressive recovery over 2 years. The second patient had a dehiscence of the roof of the petrous bone overlying the geniculate ganglion, which put the facial nerve at risk of bipolar coagulation thermal injury. LESSONS Two major mechanisms could explain the loss of facial nerve function after TL: surgery-related indirect inflammation of the nerve resulting in herpesvirus reactivation and delayed dysfunction (Bell’s palsy) or indirect thermal damage to the geniculate ganglion through a dehiscent petrous roof.

The insular cortex is now well-established as a potential site of epileptogenesis in patients with drug-resistant epilepsy, and its resection has been associated with good outcomes in terms of seizure control. However, given the role of the insula in sensory processing and in visceral information integration, it remains unclear whether insular cortex epilepsy and its surgery are associated with disturbances in sensory information processing and visceral sensation processes as experienced in daily life. In the present study, we examined such sensory disturbances in a group of patients (n = 17) who underwent epilepsy surgery involving a resection of the insula and compared them to a lesion-control group of patients with temporal epilepsy surgery (n = 22) and a healthy control group (n = 29) matched for age, gender, and education. Participants were assessed on the self-report “Adolescent/Adult Sensory Profile” questionnaire at least four months after surgery. Our series of one-way analyses of variance (ANOVAs) revealed that insular and temporal resections in patients with drug-refractory epilepsy were associated with a low “sensation seeking” behavior reflecting a lack of engagement with sensory inputs from the environment. Furthermore, insular resections were associated with impairments in the “active behavioral responses” for the gustatory/olfactory modalities. These preliminary findings suggest that insular resections may be associated with mild to moderate alterations in sensory processing.

Entrenched deep within the Sylvian fissure, the insula has long been considered one of the least understood regions of the human brain, in part due to its restricted accessibility. However, recent evidence suggests that the insula plays a key role in gustation, interoception, cognitive and emotional processes, and likely integrates these different functions to contribute to the homeostatic control of food intake. In the past decade, our team has identified the insula as a potential site of epileptogenicity, which can be successfully treated by microsurgical resection. While most surgeries are successful in controlling insular epileptic seizures and lead to few postoperative deficits, the subtle changes that may occur in food-related experiences are still unknown. Using a self-report questionnaire, the present study sought to fill this gap by assessing changes in appetite in patients who underwent unilateral partial or complete insular resections (n = 17) as part of their epilepsy surgery. We compared them to a group of patients who underwent temporal lobe epilepsy surgery (n = 22) as a lesion-control group. A majority (59%) of the insular patients reported an alteration in appetite, with most of these changes being characterized by a persistent reduction. Such changes were rarely reported following temporal lobectomy (14%). While they significantly differed in terms of appetite changes, both groups were similar when examining post-surgical changes in weight, diet, exercise and eating habits. Insular patients with altered appetite also showed behavioral signs of dysfunctional interoceptive and gustatory functions, corroborating the idea that these systems play a role in the regulation of feeding behaviours. This research pushes our understanding of the mechanisms underlying food intake and could lead to avenues for the treatment of eating disorders.

Three decades after its introduction as an adjuvant therapeutic option in the management of selective drug-resistant epilepsy cases (DRE), vagus nerve stimulation (VNS) retains growing interest. An implantable device was first approved for epilepsy in Europe in 1994 and in the United States (US) in 1997. Subsequent modifications improved the safety and the efficacy of the system. The most recent application of vagal neurostimulation is represented by transcutaneous devices that are claimed to have strong therapeutic potential. In this review, we sought to analyze the most meaningful available data describing the indications, safety and efficacy of the different approaches of VNS in clinical practice. Therefore, we identified studies reporting VNS efficacy and/or safety in epilepsy and its comorbidities from January 1990 to February 2020 from various databases including PubMed, Scopus, Cochrane, US government databases and VNS manufacturer published resources. In general, VNS efficacy becomes optimal around the sixth month of treatment and a 50-100 % seizure frequency reduction is achieved in approximately 45-65 % of the patients. However, some clinically relevant differences have been reported with specific factors such as epilepsy etiology or type, patient age as well as the delay of VNS therapy onset. VNS efficacy on seizure frequency has been demonstrated in both children and adults, in lesional and non-lesional cases, in focal and generalized epilepsies, on both seizures and epilepsy comorbidities. Regarding the latter, VNS can lead to an improvement of about 25-35 % in depression scores, 35 % in anxiety scores and 25 % in mood assessment scores. If non-invasive devices are undeniably safer, their efficacy is limited due to the scarcity of large cohort studies and the disparity of methodological approaches (study design and stimulation parameters). Overall, we believe that there is a progress margin for improving the safety of implantable devices and, above all, the effectiveness of the various VNS approaches.

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.

We present an intraoperative hyperspectral imaging system and the hemodynamics data acquired in 12 epileptic patients, allowing detection of the hemodynamic response function associated with interictal spikes, and localization of the area with the highest epileptic activity.

Objective For patients with nonlesional refractory focal epilepsy (NLRFE), localization of the epileptogenic zone is more arduous, and intracranial electroencephalography (EEG) (icEEG) is frequently required. Planning for icEEG is dependent on combined data from multiple noninvasive modalities. We report the negative impact of lack of integration of magnetoencephalography (MEG) in the presurgical workup in NLRFE. Methods Observational MEG case series involving 31 consecutive patients with NLRFE in an academic epilepsy center. For various reasons, MEG data were not analyzed in a timely manner to be included in the decision-making process. The presumed impact of MEG was assessed retrospectively. Results Magnetoencephalography would have changed the initial management in 21/31 (68%) had MEG results been available by reducing the number of intracranial electrodes, modifying their position, allowing for direct surgery, canceling the intracranial study, or providing enough evidence to justify one. Good surgical outcome was achieved in 11 out of 17 patients who proceeded to epilepsy surgery. Nine out of eleven had MEG clusters corresponding to the resection area, and MEG findings would have allowed for direct surgery (avoiding icEEG) in 2/11. Six patients had poor outcome including three patients where MEG would have significantly changed the outcome by modifying the resection margin. Magnetoencephalography provided superior information in 3 patients where inadequate coverage precluded accurate mapping of the epileptogenic zone. Conclusion In this single center retrospective study, MEG would have changed patient management, icEEG planning, and surgical outcome in a significant percentage of patients with NLRFE and should be considered in the presurgical workup in those patients.

Background: In temporal lobe epilepsy (TLE), advanced neuroimaging techniques reveal anomalies extending beyond the temporal lobe such as thinning of fronto-central cortices. Operculo-insular epilepsy (OIE) is an under-recognized and poorly characterized condition with the potential of mimicking TLE. In this work, we investigated insular and extra-insular cortical thickness (CT) changes in OIE. Methods: All participants (14 patients with refractory OIE, 9 age- and sex-matched patients with refractory TLE and 26 healthy controls) underwent a T1-weighted acquisition on a 3 T MRI. Anatomical images were processed with Advanced Normalization Tools. Between-group analysis of CT was performed using a two-sided t-test (threshold of p

Operculo-insular seizures are heterogeneous and may resemble seizures originating from the temporal, frontal, or parietal lobe. Although surface and invasive EEG recordings are often necessary to detect operculo-insular seizures, electrophysiological features of operculo-insular epilepsies remain poorly characterized. This study describes the EEG findings of patients with operculo-insular epilepsy.We reviewed electrophysiological data of all patients (n = 9) with operculo-insular seizures revealed by intracranial EEG and for whom operculo-insular epilepsy was confirmed by good seizure outcome after resective or radiosurgery at our center between 2005 and 2013. Patients were divided according to whether their seizure focus involved the anterior (group 1; n = 4) or posterior (group 2; n = 5) portion of the insula.Interictal scalp EEG was lateralizing and showed distinct topographical spike patterns between groups: frontal and temporal in group 1, temporal in group 2. Intracranial recordings showed abundant spikes limited to the operculo-insular region or involving distant areas in the frontal/temporal (group 1) and temporal/parietal lobes (group 2). Ictal intracranial EEG revealed discharges limited to the insula or simultaneously involving extrainsular contacts at onset, notably the orbitofrontal cortex (group 1) and the frontal and parietal opercula (group 2), and propagating to the frontal and temporal lobes in group 1 and to parietal and temporal lobes in group 2.Spike distribution and seizure propagation in operculo-insular epilepsy follows an anterior-to-posterior pattern mirroring an anterior or posterior insular focus localization. When presented with frontal and/or temporal epileptiform abnormalities, an operculo-insular focus should be considered.

BACKGROUND AND PURPOSE Recent studies suggest that a nonnegligible proportion of drug-resistant epilepsy surgery candidates have an epileptogenic zone that involves the insula. We aimed to examine the value of proton magnetic resonance spectroscopy (1 H-MRS) in identifying patients with insular cortex epilepsy. METHODS Patients with possible nonlesional drug-refractory insular epilepsy underwent a voxel-based 1 H-MRS study prior to an intracranial electroencephalographic (EEG) study. Patients were then divided into two groups based on invasive EEG findings: the insular group with evidence of insular seizures and the noninsular group with no evidence of insular seizures. Sixteen age-matched healthy controls were also scanned for normative data. RESULTS Twenty-two epileptic patients were recruited, 12 with insular seizures and 10 with extra-insular seizures. Ipsilateral and contralateral insular N-acetyl-aspartate concentrations ([NAA]) and NAA/Cr ratios were found to be similar in both patient groups. No significant differences in [NAA] or NAA/Cr ratios were found between the insular group, noninsular group, and healthy controls. [NAA] and NAA/Cr asymmetry indices correctly lateralized the seizure focus in only 16.7% and 0% of patients, respectively. CONCLUSIONS Our preliminary findings suggest that 1 H-MRS fares poorly in identifying patients with nonlesional insular epilepsy.

International audience; The presence of B lymphocyte-associated oligoclonal immunoglobulins in the cerebrospinal fluid is a classic hallmark of multiple sclerosis (MS). The clinical efficacy of anti-CD20 therapies supports a major role for B lymphocytes in MS development. Although activated oligoclonal populations of pathogenic B lymphocytes are able to traffic between the peripheral circulation and the central nervous system (CNS) in patients with MS, molecular players involved in this migration have not yet been elucidated. In this study, we demonstrated that activated leukocyte cell adhesion molecule (ALCAM/CD166) identifies subsets of proinflammatory B lymphocytes and drives their transmigration across different CNS barriers in mouse and human. We also showcased that blocking ALCAM alleviated disease severity in animals affected by a B cell-dependent form of experimental autoimmune encephalomyelitis. Last, we determined that the proportion of ALCAM+ B lymphocytes was increased in the peripheral blood and within brain lesions of patients with MS. Our findings indicate that restricting access to the CNS by targeting ALCAM on pathogenic B lymphocytes might represent a promising strategy for the development of next-generation B lymphocyte-targeting therapies for the treatment of MS. © 2019 The Authors.

Epilepsy is a neurological disorder characterized by chronic excessive neuronal discharges. Epilepsy surgery may be considered in patients who are resistant to drug treatment, and several tests are used during pre-operative planning to locate the epileptic focus to be resected (MRI, PET, SPECT, EEG, MEG). In some cases, intracranial EEG monitoring or intraoperative electrocorticography is required to confirm and better delineate the area to be resected. Despite available tests, epilepsy surgery outcome remains modest. We present a multimodal imaging platform connected to a neurosurgical microscope allowing intraoperative detection of intrinsic optical brain biomarkers for surgical guidance during epilepsy surgery. Hyperspectral imaging (HSI) allows detection of the hemodynamic response associated with epileptic activity, spatial frequency domain imaging (SFDI) is used for optical properties reconstruction (absorption and reduced scattering), and auto-fluorescence imaging (AFI) allows metabolic markers identification. Validation of SFDI and AFI systems was performed on optical phantoms. Acquisitions on ex vivo tissue samples demonstrate the capabilities of the system to produce fluorescence intensity maps, calibrated with optical properties obtained from SFDI to account for tissue attenuation. In vivo acquisition during epilepsy surgery with HSI allows characterization of the hemodynamic response associated with epileptic spikes.

Insular epilepsy is increasingly recognized in epilepsy surgery centers. Recent studies suggest that resection of an epileptogenic zone that involves the insula as a treatment for drug-resistant seizures is associated with good outcomes in terms of seizure control. However, despite the existing evidence of a role of the insula in emotions and affective information processing, the long-term psychological outcome of patients undergoing these surgeries remain poorly documented. A group of 27 adults (18 women) who underwent an insulo-opercular resection (in combination with a part of the temporal lobe in 10, and of the frontal lobe in 5) as part of epilepsy surgery at our center between 2004 and 2019 completed psychometric questionnaires to assess depression (Beck Depression Inventory - 2nd edition; BDI-II), anxiety (State-Trait Anxiety Inventory, Trait Version; STAI-T), and quality of life (Patient Weighted Quality of Life In Epilepsy; QOLIE-10-P). Scores were compared to those of patients who had standard temporal lobe epilepsy (TLE) surgery with similar socio-demographic and disease characteristics. Seizure control after insular epilepsy surgery was comparable to that observed after TLE surgery, with a majority of patients reporting being seizure free (insular: 63.0%; temporal: 63.2%) or having rare disabling seizures (insular: 7.4%; temporal: 18.4%) at the time of questionnaire completion. Statistical comparisons revealed no significant group difference on scores of depression, anxiety, or quality of life. Hemisphere or extent of insular resection had no significant effect on the studied variables. In the total sample, employment status and seizure control, but not location of surgery, significantly predicted quality of life. Self-reported long-term psychological status after insulo-opercular resection as part of epilepsy surgery thus appears to be similar to that observed after TLE surgery, which is commonly performed in epilepsy surgery centers.

Intraventricular rupture of a colloid cyst is a rare phenomenon and has been proposed as a mechanism for sudden death in patients with colloid cysts. Imaging of a colloid cyst during rupture has been described in only one other instance. The authors report a highly unusual case of a 53-year-old man who presented with acute onset headaches and imaging findings of hydrocephalus caused by a colloid cyst originating from the septum pellucidum and superior surface of the roof of the third ventricle. Interestingly, the colloid cyst revealed imaging signs of intraventricular rupture characterized by a tail-like drainage of cystic contents into the occipital horn of the lateral ventricle. The patient was surgically treated with a craniotomy and transcallosal approach to the colloid cyst, where it was noted that the cyst wall was spontaneously open. This rare case highlights unique imaging findings of a rare event in an infrequent pathology confirmed with intraoperative microscopy. The authors further document the process of cyst rupture and speculate on its pathomechanisms.

Objective To investigate the involvement of interleukin (IL)-26 in neuroinflammatory processes in multiple sclerosis (MS), in particular in blood-brain barrier (BBB) integrity. Methods Expression of IL-26 was measured in serum, CSF, in vitro differentiated T helper (T-H) cell subsets, and postmortem brain tissue of patients with MS and controls by ELISA, quantitative PCR, and immunohistochemistry. Primary human and mouse BBB endothelial cells (ECs) were treated with IL-26 in vitro and assessed for BBB integrity. RNA sequencing was performed on IL-26-treated human BBB ECs. Myelin oligodendrocyte glycoprotein(35-55) experimental autoimmune encephalomyelitis (EAE) mice were injected IP with IL-26. BBB leakage and immune cell infiltration were assessed in the CNS of these mice using immunohistochemistry and flow cytometry. Results IL-26 expression was induced in T-H lymphocytes by T(H)17-inducing cytokines and was upregulated in the blood and CSF of patients with MS. CD4(+)IL-26(+) T lymphocytes were found in perivascular infiltrates in MS brain lesions, and both receptor chains for IL-26 (IL-10R2 and IL-20R1) were detected on BBB ECs in vitro and in situ. In contrast to IL-17 and IL-22, IL-26 promoted integrity and reduced permeability of BBB ECs in vitro and in vivo. In EAE, IL-26 reduced disease severity and proinflammatory lymphocyte infiltration into the CNS, while increasing infiltration of Tregs. Conclusions Our study demonstrates that although IL-26 is preferentially expressed by T(H)17 lymphocytes, it promotes BBB integrity in vitro and in vivo and is protective in chronic EAE, highlighting the functional diversity of cytokines produced by T(H)17 lymphocytes. This work was funded by a grant from the Canadian Institutes of Health Research (MOP136980). A. Prat holds a senior Canada Research Chair in Multiple Sclerosis. M. Charabati held a postdoctoral studentship from the Fonds de recherche du Quebec-Sante (FRQS) and is now supported by a doctoral scholarship from the Multiple Sclerosis Society of Canada (MSSC). E. Peelen and S. Zandee held a postdoctoral studentship from the FRQS/MSSC Partnership Award. B. Broux held a postdoctoral studentship from Fonds Wetenschappelijk Onderzoek-Vlaanderen. L. Hachehouche held PhD studentships from the MSSC, FRQS, and Neuroinflammation Training Program. Prat, A (corresponding author), Univ Montreal, Fac Med, Multiple Sclerosis Clin, Res Ctr,Ctr Hosp Univ Montreal CRCHUM,Dept Neuros, Montreal, PQ, Canada. a.prat@umontreal.ca

OBJECTIVEFor patients with nonlesional refractory focal epilepsy (NLRFE), localization of the epileptogenic zone may be more arduous than for other types of epilepsy and frequently requires information from multiple noninvasive presurgical modalities and intracranial EEG (icEEG). In this prospective, blinded study, the authors assessed the clinical added value of magnetic source imaging (MSI) in the presurgical evaluation of patients with NLRFE.METHODSThis study prospectively included 57 consecutive patients with NLRFE who were considered for epilepsy surgery. All patients underwent noninvasive presurgical evaluation and then MSI. To determine the surgical plan, discussion of the results of the presurgical evaluation was first undertaken while discussion participants were blinded to the MSI results. MSI results were then presented. MSI influence on the initial management plan was assessed.RESULTSMSI results influenced patient management in 32 patients. MSI results led to the following changes in surgical strategy in 14 patients (25%): allowing direct surgery in 6 patients through facilitating the detection of subtle cortical dysplasia in 4 patients and providing additional concordant diagnostic information to other presurgical workup in another 2 patients; rejection of surgery in 3 patients originally deemed surgical candidates; change of plan from direct surgery to icEEG in 2 patients; and allowing icEEG in 3 patients deemed not surgical candidates. MSI results led to changed electrode locations and contact numbers in another 18 patients. Epilepsy surgery was performed in 26 patients influenced by MSI results and good surgical outcome was achieved in 21 patients.CONCLUSIONSThis prospective, blinded study showed that information provided by MSI allows more informed icEEG planning and surgical outcome in a significant percentage of patients with NLRFE and should be included in the presurgical workup in those patients.

PURPOSE Operculoinsular epilepsy (OIE) can be challenging to diagnose. While the value of SPECT cerebral blood flow and PET F-FDG studies for presurgical evaluation of patients with medial temporal lobe epilepsy (MTLE) is well established, it remains unclear whether they can help identify an operculoinsular epileptic focus. This study assesses the value of interictal/ictal regional cerebral blood flow (rCBF) SPECT and FDG PET for OIE diagnosis. METHODS Eighteen patients with proven OIE who underwent interictal/ictal rCBF SPECT and/or FDG-PET prior to epilepsy surgery were identified from our clinical database and were compared with a group of 18 patients who underwent MTLE surgery. Regional cerebral blood flow SPECT and FDG PET images were reevaluated visually by an expert reader blind to clinical data. RESULTS Interictal/ictal rCBF SPECT correctly identified an operculoinsular focus in 11 (65%) of 17 OIE patients and was misleading in 3 cases (18%). Secondary activation in areas connected to the insula was often observed. In the MTLE group, the area of maximal increased perfusion was congruent in 12 (75%) of 16 patients and extended to the ipsilateral insula in 1 patient. FDG PET findings were concordant with the epileptic focus in 8 (47%) of 17 OIE patients and were misleading in 4 (24%), whereas they were concordant in all MTLE patients. CONCLUSIONS Interictal/ictal rCBF SPECT can identify a concordant operculoinsular focus in a significant proportion of OIE patients and offers a valuable diagnostic tool in nonlesional cases. By contrast, the value of interictal FDG PET in this population is more equivocal.

The insula is now regarded as a potential site of epileptogenesis in drug-resistant epilepsy, and the advent of microsurgical techniques has allowed insular cortectomy to become a treatment of choice when the insular cortex is involved in the seizure focus. However, considering the evidence of an insular role in socio-emotional processing, it remains unknown whether these cortical resections disturb personality and social behavior as experienced in daily life. We examined such changes in a group of patients (n = 19) who underwent epilepsy surgery involving partial or complete resection of the insula, and compared them to a group of patients who underwent standard temporal lobe epilepsy (TLE) surgery (n = 19) as a lesion-control group. Participants were assessed on the Iowa Scales of Personality Change, filled by a close relative at least six months after surgery. While postoperative changes did not significantly differ between groups on any of the ISPC items, insular resections were associated with mild but significant increases in irritability, emotional lability, anxiety, and frugality postoperatively, which, apart from anxiety, were not significant among TLE patients. Our results are congruent with the idea that the insula contributes to emotion processing. To our knowledge, this study is the first to systematically assess personality changes in a consecutive sample of patients with insular resections.

Background Epilepsy surgeries requiring an operculoinsulectomy pose significant difficulties because the perisylvian area is highly vascular, deep, and functional. Objective To report the operative technique and results of epilepsy surgeries requiring an operculoinsular cortectomy at our institution. Methods The data of all consecutive patients who had undergone an epilepsy surgery requiring an operculoinsular cortectomy with a minimum follow-up of 1 yr were reviewed. Tumor and vascular malformation cases were excluded. Surgical techniques are described based on findings during surgery. Results Twenty-five patients underwent an epilepsy surgery requiring an operculoinsular cortectomy: mean age at surgery was 35 y (9-51), mean duration of epilepsy was 19 y (5-36), 14 were female, and mean duration of follow-up was 4.7 y (1-16). Magnetic resonance imaging of the operculoinsular area was normal or revealed questionable nonspecific findings in 72% of cases. Investigation with intracranial EEG electrodes was done in 17 patients. Surgery was performed on the dominant side for language in 7 patients. An opercular resection was performed in all but 2 patients who only had an insulectomy. Engel class I seizure control was achieved in 80% of patients. Postoperative neurological deficits (paresis, dysphasia, alteration of taste, smell, hearing, pain, and thermal perceptions) were frequent (75%) but always transient except for 1 patient with persistent mild alteration of thermal and pain perception. Conclusion Surgical treatment of operculoinsular epilepsy is effective in achieving seizure control and is associated with an acceptable long-term complication rate.

Little is known about the relation of alpha rhythms and object recognition. Alpha has been generally proposed to be associated with attention and memory and to be particularly important for the mediation of long-distance communication between neuronal populations. However, how these apply to object recognition is still unclear. This study aimed at describing the spatiotemporal dynamics of alpha rhythms while recognizing fragmented images of objects presented for the first time and presented again 24 hr later. Intracranial electroencephalography was performed in six epileptic patients undergoing presurgical evaluation. Time–frequency analysis revealed a strong alpha activity, mainly of the evoked type, propagating from posterior cerebral areas to anterior regions, which was similar whether the objects were recognized or not. Phase coherence analysis, however, showed clear phase synchronization specific for the moment of recognition. Twenty-four hr later, frontal regions displayed stronger alpha activity and more distributed phase synchronization than when images were presented for the first time. In conclusion, alpha amplitude seems to be related to nonspecific mechanism. Phase coherence analysis suggests a communicational role of alpha activity in object recognition, which may be important for the comparison between bottom–up representations and memory templates.

Approximately one in three patients with a successful epilepsy surgery will have seizure recurrence following antiepileptic drugs (AED) withdrawal. The value of postoperative testing for predicting seizure relapse after AED tapering is not clear. The purpose of this study was to review the literature for evidence on the use of postoperative investigations before AED discontinuation after successful epilepsy surgery. We were unable to identify studies on the prognostic value of postoperative magnetic resonance imaging and AED blood levels. The literature review yielded seven studies on the predictive value of electroencephalography. Four studies found no association between interictal discharges (IED) and seizure relapse. These studies suffered from various limitations due to their retrospective design and generally small cohorts. Two of the three studies reporting a positive association were prospective and provided strong evidence of an increased risk of seizure recurrence with presence of postoperative IED in successfully operated patients undergoing AED withdrawal.

Vagal nerve stimulation (VNS) therapy is an effective adjunctive treatment for chronic or recurrent treatment resistant depression. Although considered a safe procedure, increasing output current can be associated with stimulation induced side effects. We report the first case of dry cough induced by speech and mild exercise, occurring in the off mode following implantation of a vagal nerve stimulator (VNSor). We discuss the possible pathophysiology and the potential treatment options of this rare complication.

Using light, we are able to visualize the hemodynamic behavior of the brain to better understand neurovascular coupling and cerebral metabolism. In vivo optical imaging of tissue using endogenous chromophores necessitates spectroscopic detection to ensure molecular specificity as well as sufficiently high imaging speed and signal-to-noise ratio, to allow dynamic physiological changes to be captured, isolated, and used as surrogate of pathophysiological processes. An optical imaging system is introduced using a 16-bands on-chip hyperspectral camera. Using this system, we show that up to three dyes can be imaged and quantified in a tissue phantom at video-rate through the optics of a surgical microscope. In vivo human patient data are presented demonstrating brain hemodynamic response can be measured intraoperatively with molecular specificity at high speed.

Following normal neuronal activity, there is an increase in cerebral blood flow and cerebral blood volume to provide oxygenated hemoglobin to active neurons. For abnormal activity such as epileptiform discharges, this hemodynamic response may be inadequate to meet the high metabolic demands. To verify this hypothesis, we developed a novel hyperspectral imaging system able to monitor real-time cortical hemodynamic changes during brain surgery. The imaging system is directly integrated into a surgical microscope, using the white-light source for illumination. A snapshot hyperspectral camera is used for detection (4x4 mosaic filter array detecting 16 wavelengths simultaneously). We present calibration experiments where phantoms made of intralipid and food dyes were imaged. Relative concentrations of three dyes were recovered at a video rate of 30 frames per second. We also present hyperspectral recordings during brain surgery of epileptic patients with concurrent electrocorticography recordings. Relative concentration maps of oxygenated and deoxygenated hemoglobin were extracted from the data, allowing real-time studies of hemodynamic changes with a good spatial resolution. Finally, we present preliminary results on phantoms obtained with an integrated spatial frequency domain imaging system to recover tissue optical properties. This additional module, used together with the hyperspectral imaging system, will allow quantification of hemoglobin concentrations maps. Our hyperspectral imaging system offers a new tool to analyze hemodynamic changes, especially in the case of epileptiform discharges. It also offers an opportunity to study brain connectivity by analyzing correlations between hemodynamic responses of different tissue regions.

Activation of specific cortical territories by certain stimuli is known to trigger focal seizures. We report three cases of well documented operculo-insular reflex seizures, triggered by somatosensory stimuli in two and loud noises in the third. Limited operculoinsular resection resulted in an excellent outcome for all. We discuss these observations in regard to the literature on reflex epilepsy and known functions of the insula. [Published with video sequences online].

Background Precise localization of an epileptic focus in the perisylvian/insular area is a major challenge. The difficult access and the high density of blood vessels within the sylvian fissure have lead to poor coverage of intrasylvian (opercular and insular) cortex by available electrodes. Objective To report the creation of a novel electrode designed to record epileptic activity from both the insular cortex and the hidden surfaces of the opercula. Methods The hybrid operculo-insular electrode was fabricated by Ad-Tech Medical Instrument Corporation (Racine, Wisconsin). It was used in combination with regular subdural and depth electrodes for long-term intracranial recordings. The hybrid electrode, which contains both a depth and a strip (opercular) component, is inserted after microsurgical opening of the sylvian fissure. The depth component is implanted directly into the insular cortex. The opercular component has 1 or 2 double-sided recording contacts that face the hidden surfaces of the opercula. Results The hybrid operculo-insular electrode was used in 5 patients. This method of invasive investigation allowed including (2 patients) or excluding (3 patients) the insula as part of the epileptic focus and the surgical resection. It also allowed extending the epileptogenic zone to include the hidden surface of the frontal operculum in 1 patient. There were no complications related to the insertion of this new electrode. Conclusion The new hybrid operculo-insular electrode can be used for intracranial investigation of perisylvian/insular refractory epilepsy. It can contribute to increasing cortical coverage of this complex region and may allow better definition of the epileptic focus.

Objectif: Il a ete bien demontre que l'hemicraniectomie decompressive (HD) diminue la mortalite chez les patients qui ont subi un infarctus malin dans le territoire de l'artere cerebrale moyenne (ACM). Plusieurs des patients qui survivent presentent une invalidite de moderee a severe. Il existe une controverse a savoir ce qui devrait etre considere comme etant un bon resultat. Nous avons evalue la qualite de vie (QV) de patients apres une HD effectuee suite a un infarctus malin dans le territoire de l'ACM dans notre milieu. Methode: Nous avons evalue le resultat chez tous les patients ayant subi une HD suite a un infarctus malin dans le territoire de l'ACM entre 2001 et 2009 au moyen d'une analyse retrospective de dossier et un suivi telephonique chez les survivants. Nous avons determine le resultat fonctionnel au moyen de la Glasgow outcome scale, de la modified Rankin scale (mRS) et du Bartel index (BI) et la QV au moyen de la Stroke Impact Scale. Resultats: Nous avons identifie 14 patients, 6 hommes et 8 femmes, dont l'âge moyen etait de 44 ans (ecart de 27 a 57 ans). Tous les patients avaient un niveau de conscience diminue avant la chirurgie. Cinq avaient subi un accident vasculaire cerebral de l'hemisphere dominant. L'intervalle median entre l'evenement et la chirurgie etait de 45 heures (ecart de 1 a 96 heures). Deux patients sont decedes et 1 patient n'a pas pu etre rejoint pour le suivi. Parmi les 11 survivants, l'issue fonctionnelle a ete favorable chez 7 patients (63,6%), soit un score mRS < 4. Aucun patient n'etait dans un etat vegetatif persistant. La majorite des patients dont nous avons fait l'entrevue et des soignants (7 de 8), incluant ceux qui avaient subi un AVC a l'hemisphere dominant, etaient satisfaits apres un suivi median de 18 mois (ecart de 6 a 43 mois) malgre une QV alteree, particulierement dans les domaines physiques. Conclusion: La plupart des patients rapportent une QV satisfaisante malgre une invalidite significative, meme ceux qui presentent une invalidite de moderee a severe et un AVC de l'hemisphere dominant. Un infarctus malin de l'ACM de l'hemisphere dominant ne devrait pas etre considere comme une contre-indication a l'HD.

Summary Purpose: We present two methods of implantation for the investigation of suspected insular and perisylvian epilepsy that combine depth and subdural electrodes to capitalize on the advantages of each technique. Methods: Retrospective study of all intracranial EEG studies that included insular electrodes from 2004–2010. Patients were divided according to the implantation scheme. The first method (type 1) consisted of a craniotomy, insertion of insular electrodes after microdissection of the sylvian fissure, orthogonal implantation of mesiotemporal structures with neuronavigation, and coverage of the adjacent lobes with subdural electrodes. The second method (type 2) consisted of magnetic resonance imaging (MRI)–stereotactic frame-guided depth electrode implantation into insula and hippocampus using sagittal axes, and insertion of subdural electrodes through burr holes to cover the adjacent lobes. The combined implantations were developed and performed by one neurosurgeon (AB). Key Findings: Nineteen patients had an intracranial study that sampled the insula, among other regions. Sixteen patients were implanted using the first method, which allowed a mean of 4, 5, 20, 15, and 42 contacts per patient to be positioned into/over the insular, mesial temporal, neocortical temporal, parietal, and frontal areas, respectively. The second method (three patients) allowed a mean of 8, 7, 16, 6, and 9 contacts per patient to sample the same areas, respectively. The four patients in whom transient neurologic deficits occurred were investigated with use of type 1 implantation. Significance: Combined depth and subdural electrodes can be used safely to investigate complex insular/perisylvian refractory epilepsy. Choice of implantation scheme should be individualized according to presurgical data and the need for functional localization.

In this article, we review recently published data on the role of the insula in refractory partial epilepsy and summarize our own experience in the investigation and treatment of this entity. Case studies and evoked responses obtained from insular cortical stimulation reveal a wide array of clinical manifestations which may mimic temporal, frontal or parietal lobe seizures. Clinicians should hence lower their threshold to sample the insula with intracerebral electrodes. Lack of recognition of insular seizures may explain part of epilepsy surgery failures. Advances in microneurosurgery open the way to safer insular resection.

Object The insular region has long been neglected in the investigation and treatment of refractory epilepsy. Surgery in the insular region is rarely performed because of the risk of injury to the opercula, the arteries transiting on the surface of the insula, and the deep structures such as the basal ganglia and the internal capsule. This study was undertaken to report the results of insular surgery using modern microsurgical techniques in patients with epilepsy. Methods The authors performed a retrospective study of cases involving patients who underwent surgery for insular lesions associated with epilepsy over the last 10 years. In the majority of patients, intracranial electrodes were implanted with neuronavigation guidance to confirm the localization of the epileptic foci. Results Nine patients underwent insular surgery: 7 for refractory epilepsy with no tumor and 2 for tumors associated with seizures. Four of the resections were performed in the left hemisphere. After an average follow-up of 54 months (range 14–122 months), Engel Class IA outcome had been achieved in 6 of 7 cases in the Epilepsy Surgery Group. The remaining patient had an Engel Class III outcome after partial insular resection but later became seizurefree (Engel Class IA) following insular Gamma Knife surgery. Postoperatively, the majority of patients suffered from minor reversible hemipareses that disappeared completely within a few months. There was no surgical mortality. Conclusions Insular surgery is both safe and beneficial when it is well planned and performed with modern microsurgical techniques and good anatomical knowledge. Insulectomy is associated with little permanent morbidity and a high rate of seizure control. To the authors' knowledge, this is the first series of insulectomies predominantly performed for refractory epilepsy since those performed by Penfield.

Background:Recently a high prevalence of asystole was found in individuals with refractory epilepsy.Objective:To measure the prevalence and characterize the pattern of ictal bradycardia (IB) in our cohort.Method:We analyzed ictal heart rate (HR) and seizure localization in 69 consecutive individuals with intractable epilepsy. Ictal bradycardia was defined by HR less than 60 beat per min (bpm) and a fall of more than 30 bpm.Results:Ictal bradycardia was observed in 1.9% of seizures and in five individuals (7.2%), who presented IB in 5.7% of their seizures. Four of them had also relative IB (a decrease of HR of more than10 bpm) in the majority of their seizures. Four additional individuals showed relative IB.Conclusion:Ictal bradycardia occurs more frequently than previously thought in individuals with refractory epilepsy. Recognition of individuals with small to moderate ictal HR decrease may help to identify those at greatest risk for asystole.

OBJECT Surgery in the insular region is considered challenging because of its vascular relationships, the proximity of functional structures, and its deep location in the sylvian fissure. The authors report the incidence and consequences of ischemic lesions after operculoinsular corticectomy for refractory epilepsy. METHODS The authors retrospectively reviewed the data of all patients who underwent an insular resection with or without an opercular resection for refractory epilepsy at their center. All patients underwent postoperative MRI, enabling a radiological analysis of the ischemic lesions as a result of the corticectomies. The resections were classified according to the location and extent of the insular corticectomy and the type of operculectomy. Each patient underwent clinical follow-up. RESULTS Twenty patients underwent surgery. All patients underwent insular corticectomy with or without an operculectomy. Ischemic lesions were identified in 12 patients (60%). In these patients, 11 ischemic lesions (55%) were related to the insular corticectomy, and 1 was related to the associated periinsular resection. The ischemic lesions associated with the insulectomies were typically located in the corona radiata running from the insula to the periventricular region. Nine patients (45%) developed a postoperative neurological deficit, among whom 6 (67%) had an insular corticectomy–related ischemic lesion. All reported neurological deficits were transient. Five patients (25%) had ischemic lesions without neurological deficit. CONCLUSIONS Operculoinsular corticectomies are associated with ischemic lesions in approximately 60% of patients. However, given that no patient had a definitive postoperative deficit, these ischemic lesions have few clinical consequences. Therefore, this surgical procedure can be considered reasonably safe for the treatment of refractory epilepsy.

Induction of cyclooxygenase-2 (COX-2) has been described in a wide range of neurological diseases including animal models of epilepsy. The present study was undertaken to assess COX-2 expression in hippocampal biopsies from patients with therapy-refractive temporal lobe epilepsy (TLE). For this purpose, hippocampal CA1 subfield was dissected from epileptic patients with (n=5) or without (n=2) hippocampal sclerosis (HS). COX-2 expression was investigated using immunohistochemistry and semi-quantitative RT-PCR. COX-2 immunoreactivity in TLE patient material in the absence of HS was restricted to a few neurons of the hippocampus. In the presence of HS, on the other hand, a significant induction of astrocytic COX-2 immunoreactivity associated with a concomitant increase in the steady-state level of COX-2 mRNA was observed in the CA1 subfield. These findings suggest that induction of astrocytic COX-2 is implicated in the pathogenesis of HS in TLE and is consistent with the previous findings of increased concentrations of prostaglandins in the cerebrospinal fluid of these patients.

Introduction To perform a systematic review and individual participant data meta-analysis, to determine the efficacy and safety of MR-guided laser interstitial thermoablative therapy (MRgLITT) for drug-resistant epilepsy. Our secondary objective was to determine the effect of patient's age and etiology on the success of the procedure. Material and methods We included cohort studies of consecutive participants undergoing MRgLITT that reported outcome. The outcome was defined as the time to seizure recurrence. We performed title, abstract and full text screening independently and in duplicate. We resolved disagreements through discussion. To identify independent predictors of outcome following MRgLITT, we performed univariate Cox proportional hazards regression analysis to identify variables with a P value of less than 0.2 to be entered into a multivariate Cox proportional hazards regression model. Results Of 4308 citations, 12 articles reporting on 92 participants were eligible. The median duration of follow-up was 12 (range 1–38.5) months and 53 (57.6%) participants were seizure-free (Engel class 1) at follow-up. The mean duration of seizure freedom following MRgLITT was 19.4 months (95% CI, 15.0–23.8). Patient age and history of prior surgery were not predictors of outcome on Cox regression univariate analysis. We identified a difference in efficacy dependent on etiology but we were underpowered to conclude a statistically significant difference. Hypothalamic hamartoma had better seizure freedom than MTS/MTA, and both were superior to FCD, although this was not statistically significant. There was no procedure-related mortality, but morbidity was experienced in 14 (15.2%) of participants mainly comprising probe/device malfunction, unexpected neurological deficit, hemorrhage, or cerebral edema. Conclusion The best available evidence suggests that MRgLITT is a variably effective procedure dependent on etiology, is associated with reduced length of stay postoperatively and has a moderate morbidity profile. It should be considered first line treatment in drug-resistant epilepsy due to hypothalamic hamartoma.

A 44-year-old male presented with a 3-week history of clumsiness and numbness of the left hemibody. CT scan and MRI revealed a 2 cm mass in the right hemisphere of the cerebellum. The patient underwent a sub-occipital craniotomy with gross total resection of the intra-parenchymal lesion. On pathology, the lesion was found to be compatible with a mesenchymal chondrosarcoma. The patient received adjuvant radiation treatment and remains free of disease 60 months after completion of treatment. Mesenchymal chondrosarcomas are neoplasms that rarely arise intra-cranially. Thirty cases have been found in the literature. Our case resembles more closely six of these cases because the tumour had no dural attachment. We describe our case in more detail and review similar cases found in the English literature.

Purpose. Somatosensory (SSA) and pharyngolaryngeal auras (PLA) may suggest an extratemporal onset (e.g., insula, second somatosensory area). We sought to determine the prognostic significance of SSA and PLA in temporal lobe epilepsy (TLE) patients undergoing epilepsy surgery. Methods. Retrospective review of all patients operated for refractory TLE at our institution between January 1980 and July 2007 comparing outcome between patients with SSA/PLA to those without. Results. 158 patients underwent surgery for pharmacoresistant TLE in our institution. Eleven (7%) experienced SSA/PLA as part of their seizures. All but one had lesional (including hippocampal atrophy/sclerosis) TLE. Compared to patients without SSA or PLA, these patients were older (P=0.049), had a higher prevalence of early ictal motor symptoms (P=0.022) and prior CNS infection (P=0.022), and were less likely to have a localizing SPECT study (P=0.025). A favorable outcome was achieved in 81.8% of patients with SSA and/or PLA and 90.4% of those without SSA or PLA (P>0.05). Conclusion. Most patients with pharmacoresistant lesional TLE appear to have a favorable outcome following temporal lobectomy, even in the presence of SSA and PLA.

Summary: Purpose: Intensive long-term monitoring (LTM) for patients with refractory seizures is common and expensive. Methods to decrease the length of stay would improve patient experience and reduce cost. Therefore, we prospectively analyzed seizure occurrence in 36 patients who had LTM. Methods: Antiepileptic drug (AED) levels and reduction were monitored and seizures were related to these changes. Patients were divided into temporal and extratemporal groups. Results: Twenty patients had partial seizures of temporal lobe origin. The temporal lobe partial seizures occurred between LTM days 1 and 16. All but 4 of the patients required reduction or discontinuation of a least one AED and had subtherapeutic levels of the tapered medications. In 16 patients with extratemporal partial seizures, seizures occurred between LTM days 1 and 8. Six of these patients required reduction of at least one AED, and 5 of the 6 had subtherapeutic levels of that medication. These differences between length of monitoring monitoring and AED reduction in temporal and extratemporal patients were statistically significant. The groups did not differ significantly with respect to number or identity of tapered or nontapered medications or levels of nontapered medications. Reported seizure frequency at home was significantly related to number of seizures recorded in the temporal group only. The only significant predictor of secondarily generalized seizure activity during monitoring was a history of such activity occurring at home. Conclusions: We conclude that patients with extratemporal partial seizures need little reduction of AED for seizures to be captured in a minimal time period. Patients with temporal lobe seizures, however, required drastic reduction of AEDs to allow capture of seizures in a long time period.

Induced gamma-band response (iGBR) has been linked to coherent perception of images and is thought to represent the synchronisation of neuronal populations mediating binding of elements composing the image and the comparisons with memory for proper recognition. This study uses fragmented images with intracranial electroencephalography to investigate the precise spatio-temporal dynamic of iGBR elicited by the recognition of objects presented for the first time and 24 h later. Results show an increased iGBR at recognition in regions involved in bottom-up processes such as the cuneus and the lateral occipital complex. Top-down facilitation involved the lingual gyrus, the precuneus and the superior parietal lobule when images were presented for the first time. Twenty-four hours later, top-down facilitation was mediated by frontal areas involved in retrieval from episodic memory. This study showed that the classically reported iGBR is related to object recognition and that top-down processes vary according to task demand.