Resection Of Cortex Research Articles

Chloride deregulation and GABA depolarization in MTOR related malformations of cortical development.

Focal Cortical Dysplasia, Hemimegalencephaly and Cortical Tuber are pediatric epileptogenic malformations of cortical development (MCDs) frequently pharmaco-resistant and mostly surgically treated by the resection of epileptic cortex. Availability of cortical resection samples allowed significant mechanistic discoveries directly from human material. Causal brain somatic or germline mutations in the AKT/PI3K/DEPDC5/MTOR genes were identified. GABAa mediated paradoxical depolarization, related to altered chloride (Cl-) homeostasis, was shown to participate to ictogenesis in human pediatric MCDs. However, the link between genomic alterations and neuronal hyperexcitability is still unclear. Here we studied the post translational interactions between the mTOR pathway and the regulation of cation-chloride cotransporters (CCC), KCC2 and NKCC1, that are largely responsible for controlling intracellular Cl- and ultimately GABAergic transmission. For this study, 35 children (25 MTORopathies and 10 pseudo controls, diagnosed by histology plus genetic profiling) were operated for drug resistant epilepsy. Postoperative cortical tissues were recorded on multielectrode array (MEA) to map epileptic activities. CCC expression level and phosphorylation status of the WNK1/SPAK-OSR1 pathway was measured during basal conditions and after pharmacological modulation. Direct interactions between mTOR and WNK1 pathway components were investigated by immunoprecipitation. Membranous incorporation of MCD samples in Xenopus laevis oocytes enabled Cl- conductance and equilibrium potential (EGABA) for GABA measurement. Of the 25 clinical cases, half harbored a somatic mutation in the mTOR pathway, while pS6 expression was increased in all MCD samples. Spontaneous interictal discharges were recorded in 65% of the slices. CCC expression was altered in MCDs, with a reduced KCC2/NKCC1 ratio and decreased KCC2 membranous expression. CCC expression was regulated by the WNK1/SPAK-OSR1 kinases through direct phosphorylation of Thr906 on KCC2, that was reversed by WNK1 and SPAK antagonists (NEM and Staurosporine). mSIN1 subunit of MTORC2 was found to interact with SPAK-OSR1 and WNK1. Interactions between these key epileptogenic pathways could be reversed by the mTOR specific antagonist Rapamycin, leading to a dephosphorylation of CCCs and recovery of the KCC2/NKCC1 ratio. The functional effect of such recovery was validated by the restoration of the depolarizing shift in EGABA by rapamycin, measured after incorporation of MCD membranes to X. laevis oocytes, in line with a reestablishment of normal ECl-. Our study deciphers a protein interaction network through a phosphorylation cascade between MTOR and WNK1/SPAK-OSR1 leading to chloride cotransporters deregulation, increased neuronal chloride levels and GABAa dysfunction in malformations of Cortical Development, linking genomic defects and functional effects and paving the way to target epilepsy therapy.

Holistic processing and face expertise after pediatric resection of occipitotemporal cortex

The nature and extent of hemispheric lateralization and its potential for reorganization continues to be debated, although there is general agreement that there is a right hemisphere (RH) advantage for face processing in human adults. Here, we examined face processing and its lateralization in individuals with a single preserved occipitotemporal cortex (OTC), either in the RH or left hemisphere (LH), following early childhood resection for the management of drug-resistant epilepsy. The matched controls and those with a lesion outside of OTC evinced the standard superiority in processing upright over inverted faces and the reverse sensitivity to a nonface category (bicycles). In contrast, the LH and the RH patient groups were significantly less accurate than the controls and showed mild orientation sensitivities at best (and not always in the predicted directions). For the two patient groups, the accuracies of face and bicycle processing did not differ from each other and were not obviously related to performance on intermediate level global form tasks with, again, poorer thresholds for both patient groups than controls and no difference between the patient groups. These findings shed light on the complexity of hemispheric lateralization and face and nonface object processing in individuals following surgical resection of OTC. Overall, this study highlights the unique dynamics and potential for plasticity in those with childhood cortical resection.

Delineating abnormal individual structural covariance brain network organization in pediatric epilepsy with unilateral resection of visual cortex

Although several previous studies have used resting-state functional magnetic resonance imaging and diffusion tensor imaging to report topological changes in the brain in epilepsy, it remains unclear whether the individual structural covariance network (SCN) changes in epilepsy, especially in pediatric epilepsy with visual cortex resection but with normal functions. Herein, individual SCNs were mapped and analyzed for seven pediatric patients with epilepsy after surgery and 15 age-matched healthy controls. A whole-brain individual SCN was constructed based on an automated anatomical labeling template, and global and nodal network metrics were calculated for statistical analyses. Small-world properties were exhibited by pediatric patients after brain surgery and by healthy controls. After brain surgery, pediatric patients with epilepsy exhibited a higher shortest path length, lower global efficiency, and higher nodal efficiency in the cuneus than those in healthy controls. These results revealed that pediatric epilepsy after brain surgery, even with normal functions, showed altered topological organization of the individual SCNs, which revealed residual network topological abnormalities and may provide initial evidence for the underlying functional impairments in the brain of pediatric patients with epilepsy after surgery that can occur in the future.

Extent of piriform cortex resection in children with temporal lobe epilepsy.

A greater extent of resection of the temporal portion of the piriform cortex (PC) has been shown to be associated with higher likelihood of seizure freedom in adults undergoing anterior temporal lobe resection (ATLR) for drug-resistant temporal lobe epilepsy (TLE). There have been no such studies in children, therefore this study aimed to investigate this association in a pediatric cohort. A retrospective, neuroimaging cohort study of children with TLE who underwent ATLR between 2012 and 2021 was undertaken. The PC, hippocampal and amygdala volumes were measured on the preoperative and postoperative T1-weighted MRI. Using these volumes, the extent of resection per region was compared between the seizure-free and not seizure-free groups. In 50 children (median age 9.5 years) there was no significant difference between the extent of resection of the temporal PC in the seizure-free (median = 50%, n = 33/50) versus not seizure-free (median = 40%, n = 17/50) groups (p = 0.26). In a sub-group of 19 with ipsilateral hippocampal atrophy (quantitatively defined by ipsilateral-to-contralateral asymmetry), the median extent of temporal PC resection was greater in children who were seizure-free (53%) versus those not seizure-free (19%) (p = 0.009). This is the first study demonstrating that, in children with TLE and hippocampal atrophy, more extensive temporal PC resection is associated with a greater chance of seizure freedom-compatible with an adult series in which 85% of patients had hippocampal sclerosis. In a combined group of children with and without hippocampal atrophy, the extent of PC resection was not associated with seizure outcome, suggesting different epileptogenic networks within this cohort.

Intact speech perception after resection of dominant hemisphere primary auditory cortex for the treatment of medically refractory epilepsy: illustrative case.

In classic speech network models, the primary auditory cortex is the source of auditory input to Wernicke's area in the posterior superior temporal gyrus (pSTG). Because resection of the primary auditory cortex in the dominant hemisphere removes inputs to the pSTG, there is a risk of speech impairment. However, recent research has shown the existence of other, nonprimary auditory cortex inputs to the pSTG, potentially reducing the risk of primary auditory cortex resection in the dominant hemisphere. Here, the authors present a clinical case of a woman with severe medically refractory epilepsy with a lesional epileptic focus in the left (dominant) Heschl's gyrus. Analysis of neural responses to speech stimuli was consistent with primary auditory cortex localization to Heschl's gyrus. Although the primary auditory cortex was within the proposed resection margins, she underwent lesionectomy with total resection of Heschl's gyrus. Postoperatively, she had no speech deficits and her seizures were fully controlled. While resection of the dominant hemisphere Heschl's gyrus/primary auditory cortex warrants caution, this case illustrates the ability to resect the primary auditory cortex without speech impairment and supports recent models of multiple parallel inputs to the pSTG.

Contralateral synaptic changes following severe unilateral brain injury

The brain is highly integrated and thus unilateral injury can impact the contralateral hemisphere. However, further research is needed to clarify the changes in the response of the contralateral homotopic area to ipsilateral injury. We hypothesized that severe unilateral brain injury would be accompanied by contralateral synaptic changes that are related to functional recovery. To test this, we divided rats into sham and experimental groups. In the experimental group, we performed right motor cortex resection. These rats were further divided into three subgroups according to post-injury time: 7 days, 14 days, and 30 days post-injury. Rats in each group were evaluated using a beam walking test to quantify the recovery of motor function, and all rats received an injection of adeno-associated virus-containing green fluorescent protein (GFP). Finally, we conducted morphological and histological analyses to identify synaptic changes. Over time, the behavior of the rats that underwent right motor cortex resection recovered. Furthermore, in contrast to the sham group, the experimental groups exhibited an increase in the spine density and expression of synaptic proteins in layer V of the contralateral motor cortex, which was consistent with the GFP-labeled neurons. Moreover, more immature spines were observed 7 days post-injury. Notably, spine morphology matured from 7 to 30 days, and the increase in Synapsin-1 intensity in layer V peaked 14 days after the resection, whereas PSD-95 intensity continued to increase until day 30. Our findings suggested that following motor function recovery from unilateral brain injury, spine morphology and synaptic proteins change dynamically in the contralateral hemisphere.

Piriform Cortex Ablation Volume Is Associated With Seizure Outcome in Mesial Temporal Lobe Epilepsy

Growing evidence suggests that piriform cortex resection during anterior temporal lobectomy is important for achieving good seizure outcome in mesial temporal lobe epilepsy (mTLE). However, the relationship between seizure outcome and piriform cortex ablation during MR-guided laser interstitial thermal therapy (MRgLITT) remains unclear. To determine whether ablation of piriform cortex was associated with seizure outcome in patients with mTLE undergoing MRgLITT. We performed preablation and postablation volumetric analyses of hippocampus, amygdala, piriform cortex, and ablation volumes in patients with mTLE who underwent MRgLITT at our institution from 2014 to 2019. Thirty nine patients with mTLE were analyzed. In univariate logistic regression, percent piriform cortex ablation was associated with International League Against Epilepsy (ILAE) class 1 at 6 months (odds ratio [OR] 1.051, 95% CI [1.001-1.117], P = .045), whereas ablation volume, percent amygdala ablation, and percent hippocampus ablation were not ( P > .05). At 1 year, ablation volume was associated with ILAE class 1 (OR 1.608, 95% CI [1.071-2.571], P = .021) while percent piriform cortex ablation became a trend (OR 1.050, 95% CI [0.994-1.109], P = .054), and both percent hippocampus ablation and percent amygdala ablation were not significantly associated with ILAE class 1 ( P > .05). In multivariable logistic regression, only percent piriform cortex ablation was a significant predictor of seizure freedom at 6 months (OR 1.085, 95% CI [1.012-1.193], P = .019) and at 1 year (OR 1.074, 95% CI [1.003-1.178], P = .041). Piriform cortex ablation volume is associated with seizure outcome in patients with mTLE undergoing MRgLITT. The piriform cortex should be considered a high yield ablation target to achieve good seizure outcome.

Decreased self-reported appetite following insular cortex resection in patients with epilepsy

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.

Cognitive and developmental outcomes after pediatric insular epilepsy surgery for focal cortical dysplasia.

Cognitive risk associated with insular cortex resection is not well understood. The authors reviewed cognitive and developmental outcomes in pediatric patients who underwent resection of the epileptogenic zone involving the insula. A review was conducted of 15 patients who underwent resective epilepsy surgery involving the insular cortex for focal cortical dysplasia, with a minimum follow-up of 12 months. The median age at surgery was 5.6 years (range 0.3-13.6 years). Developmental/intelligence quotient (DQ/IQ) scores were evaluated before surgery, within 4 months after surgery, and at 12 months or more after surgery. Repeated measures multivariate ANOVA was used to evaluate the effects on outcomes of the within-subject factor (time) and between-subject factors (resection side, anterior insular resection, seizure control, and antiepileptic drug [AED] reduction). The mean preoperative DQ/IQ score was 60.7 ± 22.8. Left-side resection and anterior insular resection were performed in 9 patients each. Favorable seizure control (International League Against Epilepsy class 1-3) was achieved in 8 patients. Postoperative motor deficits were observed in 9 patients (permanent in 6, transient in 3). Within-subject changes in DQ/IQ were not significantly affected by insular resection (p = 0.13). Postoperative changes in DQ/IQ were not significantly affected by surgical side, anterior insular resection, AED reduction, or seizure outcome. Only verbal function showed no significant changes before and after surgery and no significant effects of within-subject factors. Resection involving the insula in children with impaired development or intelligence can be performed without significant reduction in DQ/IQ, but carries the risk of postoperative motor deficits.

Deep brain stimulation for seizure control in drug-resistant epilepsy

Antiepileptic drugs prevent morbidity and death in a large number of patients suffering from epilepsy. However, it is estimated that approximately 30% of epileptic patients will not have adequate seizure control with medication alone. Resection of epileptogenic cortex may be indicated in medically refractory cases with a discrete seizure focus in noneloquent cortex. For patients in whom resection is not an option, deep brain stimulation (DBS) may be an effective means of seizure control. Deep brain stimulation targets for treating seizures primarily include the thalamic nuclei, hippocampus, subthalamic nucleus, and cerebellum. A variety of stimulation parameters have been studied, and more recent advances in electrical stimulation to treat epilepsy include responsive neurostimulation. Data suggest that DBS is effective for treating drug-resistant epilepsy.

Neural Networks Mediating High-Level Mentalizing in Patients With Right Cerebral Hemispheric Gliomas.

Mentalizing is the ability to understand others’ mental state through external cues. It consists of two networks, namely low-level and high-level metalizing. Although it is an essential function in our daily social life, surgical resection of right cerebral hemisphere disturbs mentalizing processing with high possibility. In the past, little was known about the white matter related to high-level mentalizing, and the conservation of high-level mentalizing during surgery has not been a focus of attention. Therefore, the main purpose of this study was to examine the neural networks underlying high-level mentalizing and then, secondarily, investigate the usefulness of awake surgery in preserving the mentalizing network. A total of 20 patients with glioma localized in the right hemisphere who underwent awake surgery participated in this study. All patients were assigned to two groups: with or without intraoperative assessment of high-level mentalizing. Their high-level mentalizing abilities were assessed before surgery and 1 week and 3 months after surgery. At 3 months after surgery, only patients who received the intraoperative high-level mentalizing test showed the same score as normal healthy volunteers. The tract-based lesion symptom analysis was performed to confirm the severity of damage of associated fibers and high-level mentalizing accuracy. This analysis revealed the superior longitudinal fascicles (SLF) III and fronto-striatal tract (FST) to be associated with high-level mentalizing processing. Moreover, the voxel-based lesion symptom analysis demonstrated that resection of orbito-frontal cortex (OFC) causes persistent mentalizing dysfunction. Our study indicates that damage of the OFC and structural connectivity of the SLF and FST causes the disorder of mentalizing after surgery, and assessing high-level mentalizing during surgery may be useful to preserve these pathways.

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BACKGROUND: Of the ~50 million cases of epilepsy worldwide, an estimated 80% originate from cortical areas implicated in language. Although the precise language loci can vary significantly across individuals, electrical stimulation mapping for eloquent areas has become standard of care in resective surgery for frontotemporal epilepsies. Although considerable work has been done to establish the minimum necessary resection distance from these sites to preserve language, no previous work has shown how these representations are affected by proximal resections. METHODS: Between 1967 and 2005, 22 patients [seizure onset (y): 11.5 (0.2–33); age at initial resection (y): 27.7 (10–39); time between operations (y): 8.4 (1–20.3); sex: 14 females; hemisphere: 21 left] underwent repeated perisylvian resective epilepsy surgeries of the language-dominant hemisphere. Each set of operations comprised intraoperative language mapping and cortical photographs. Using this data, a Bayesian hierarchical model was used to estimate the variability of language localization pre-resection Versus post-resection. RESULTS: The statistical model shows the posterior median difference in cortical location of language sites preresection Versus postresection is 0.6 cm, with a posterior 95% CI of 0.4 cm, 0.9 cm. CONCLUSION: This work suggests permanence in cortical language centers following resection of infringing cortex, while providing a reasonable statistical method to impute unobserved sites during the mappings, and confirming the validity of using proximity sites defined by shortest distance in the current literature.

Neurologic Outcome After Resection of Parietal Lobe Including Primary Somatosensory Cortex: Implications of Additional Resection of Posterior ParietalCortex.

Postoperative neurologic outcomes after primary somatosensory cortex (S1) resection have not been well documented. This study was designed to evaluate the neurologic deterioration that follows resection of the S1 areas and to assess the risk factors associated with these morbidities. We reviewed 48 consecutive patients with medically intractable epilepsy who underwent resection of the S1 and/or the adjacent cortex. The 48 patients were categorized into 4 groups according to the resected area as seen on postoperative magnetic resonance images: group 1 (resection of S1 only; n= 4), 2 (the posterior parietal cortex [PPC] only; n= 24), 3 (S1 and PPC; n= 10), and 4 (S1 and precentral gyrus; n= 10). After the resection of S1 areas, 19 patients (40%) experienced neurologic worsening, including 6 (13%) with permanent and 13 (27%) with transient deficits. Patients with permanent deficits included 2 with motor dysphasia, 1 with dysesthesia, 2 with equilibrium impairments, and 1 with fine movement disturbance of the hand. The overall and permanent neurologic risks were 25% and 0% in group 1, 17% and 4% in group 2, 80% and 20% in group 3, and 60% and 30% in group 4, respectively. Multivariate analysis determined that the resection of both S1 and PPC was the only significant risk factor for neurologic deficits (P= 0.002). The neurologic risk of the resection of S1 and/or its adjacent cortical areas was 40%. The additional resection of the PPC was significantly associated with the development of postoperative neurologic impairments.

Insular Cortex Surgery for the Treatment of Refractory Epilepsy.

Focal epilepsy originating from the insular cortex is rare. One reason is the small amount of cortical tissue compared with other lobes of the brain. However, the incidence of insular epilepsy might be underestimated because of diagnostic difficulties. The semiology and the surface EEG are often not meaningful or even misleading, and elaborated imaging might be necessary. The close connections of the insular cortex with other potentially epileptogenic areas, such as the temporal lobe or frontal/central cortex, is increasingly recognized as possible reason for failure of epilepsy surgery for temporal or extratemporal seizures. Therefore, some centers consider invasive EEG recording of the insular cortex not only in case of insular epilepsy but also in other focal epilepsies with nonconclusive results from the presurgical work-up. The surgical approach to and resection of insular cortex is challenging because of its deep location and proximity to highly eloquent brain structures. Over the last decades, technical adjuncts like navigation tools, electrophysiological monitoring and intraoperative imaging have improved the outcome after surgery. Nevertheless, there is still a considerable rate of postoperative transient or permanent deficits, in some cases as unavoidable and calculated deficits. In most of the recent series, seizure outcome was favorable and comparable with extratemporal epilepsy surgery or even better. Up to now, the data volume concerning long-term follow-up is limited. This review focusses on the surgical challenges of resections to treat insular epilepsy, on prognostic factors concerning seizure outcome, on postoperative deficits and complications. Moreover, less invasive surgical techniques to treat epilepsy in this highly eloquent area are summarized.

Treatment of low-grade malignant bone tumor of limb by half-side cortical resection and inactivated replantation

Objective To study the curative effect of side bone cortex resection and inactivated replantation in the treatment of low limb malignant bone tumor. Methods 58 patients who diagnosed and treated for low limb malignant bone tumor were selected as the research subjects, and they were randomly divided into observation group and control group, each group in 29 cases.The artificial joint replacement was used in patients with the ordinary routine therapy, the observation group received side a thorough treatment of the wounded inactivated bone cortex excision.The clinical curative effect, operation indicators, and postoperative infection were compared and analyzed in the two groups. Results The total effective rate of the observation group was 96.55% (17 cases had marked effect, effective in 11 cases, failure in 1 case). The total effective rate of the control group was 72.41% (9 cases had marked effect, effective in 12 cases, failure in 8 cases), the clinical curative effect of the observation group was significantly higher than the control group (χ2=6.44, P<0.05). In addition, the anxiety and the operation indicators between the two groups had statistically significant differences (t1=5.47, t2=5.47, all P<0.05, the former is superior to the latter). Conclusion Side bone cortex inactivated replantation in the treatment of low-grade malignant bone tumor resection patients can effectively shorten the operation time and reduce the intraoperative blood loss, bad mood, and also can alleviate patients to obtain ideal therapeutic effect, clinical should be vigorously promoted. Key words: The wounded side of cortical bone resection inactivated; Bone neoplasms; The curative effect

Intraoperative fast ripples independently predict postsurgical epilepsy outcome: Comparison with other electrocorticographic phenomena

In the surgical management of epilepsy, the resection of cortex exhibiting interictal fast ripples (250–500Hz) on electrocorticography has been linked to postoperative seizure-freedom. Although fast ripples appear to accurately identify the epileptogenic zone—the minimum tissue that must be removed at surgery to achieve seizure-freedom—it has not been established that fast ripples are a superior biomarker in comparison with multimodal presurgical neuroimaging and other electrocorticography abnormalities. Hence, in the prediction of postoperative seizure-freedom, we compared the value of fast ripples with other intraoperative electocorticography abnormalities including focal slowing, paroxysmal fast activity, intermittent spike discharges, continuous epileptiform discharges, focal attenuation, and intraoperative seizures, as well as complete resection of the lesion defined by MRI and other neuroimaging. In a cohort of 60 children with lesional epilepsy and median postsurgical follow-up exceeding 4 years, who underwent resective epilepsy surgery with intraoperative electrocorticography, we evaluated the extent to which removal of each intraoperative electrocorticography abnormality impacts time to first postoperative seizure using the Kaplan-Meier method and Cox proportional hazards regression. Secondly, we contrasted the predictive value of resection of each competing electrocorticography abnormality using standard test metrics (sensitivity, specificity, positive predictive value, and negative predictive value). In contrast with all other intraoperative electrocorticography abnormalities, fast ripples demonstrated the most favorable combination of positive predictive value (100%) and negative predictive value (76%) in the prediction of postoperative seizures. Among all candidate electrocorticography features, time to first postoperative seizure was most strongly associated with incomplete resection of fast ripples (hazard ratio=19.8, p<0.001). In multivariate survival analyses, postoperative seizures were independently predicted by incomplete resection of cortex generating fast ripples (hazard ratio=25.4, 95%CI 6.71–96.0, p<0.001) and focal slowing (hazard ratio=5.79, 95%CI 1.76–19.0, p=0.004), even after adjustment for the impact of an otherwise complete resection. All children with incomplete resection of interictal FR-generating cortex exhibited postoperative seizures within six months. Notably, this cohort included many patients with large resections and thus limited opportunity to exhibit unresected fast ripples. Future study in a cohort with small resection volume, or a clinical trial in which resection margins are guided by fast ripple distribution, would likely yield a more precise estimate of the risk posed by unresected fast ripples. With a high detection rate during brief intraoperative electrocorticography and favorable positive and negative predictive value, interictal fast ripple characterization during surgery is a feasible and useful adjunct to standard methods for epilepsy surgery planning, and represents a valuable spatially-localizing biomarker of the epileptogenic zone, without the need for prolonged extraoperative electrocorticography.

Study on establishment of spastic cerebral palsy model of macaque by partial resection of motor cortex

Objective To establish spastic cerebral palsy model of macaque by partial resection of motor cortex and explore its evaluation method. Methods Four individuals of 3-month-old macaques were divided into healthy control group and operation model group according to random number table.Partial resection of the motor cortex was carried out in operation model group, in which precentral gyrus cortex from above the right lateral cerebral fissure to the inter-hemicerebral fissure, together with the posterior- superior frontal gyrus (about 0.3 to 0.5 cm in front of the anterior median sulcus) cortex were removed with the depth of about 0.5 to 0.6 cm.After the operation, the continuous camera shooting was used to record whether left limb motor dysfunction and abnormal posture existed or not.Muscle tension was assessed by manual examination of muscle tone with reference to the modified Ashworth scale.The quantitative indexes of the two groups were detected by using the gross motor and fine motor assessment scale.9.4T magnetic resonance imaging (MRI) was used to detect the brain imaging changes. Results After operation, the macaque in the operation model group immediately showed left hemiparesis, left upper limb abnormal lifting, left lower limb paralysis, left limb claudication, and eating mainly relied on the right side of the body.After 6 weeks of operation, left limb activity of the operation model group was significantly lower than that of the healthy control group, and the gross motor scores and fine motor scores were significantly lower than those of the healthy control group(Friedman test: χ2=33.939, P<0.05; χ2=37.526, P<0.05). The macaque in the operation model group showed some symptoms that abnormal posture mainly tilted to the left for the rest, sitting in a corner of the monkey cage, left arm was put on the cage to maintain postural balance, and movement was left slightly inclined, which had simulated the typical clinical manifestations of human spastic hemiplegic cerebral palsy.Muscle tension was checked by hand, and the left limb paralysis and muscle tension decreased after operation in the model group, and the left muscle tension increased gradually after 5 weeks, and gradually increased to score 4 points and the score remained 3 after 10 weeks.Brain MRI of 3 weeks postoperatively suggested scar tissue formation after right motor cortex resection, which supported the pathological changes of the hemiplegic cerebral palsy models. Conclusions Through the partial resection of the motor cortex, the model of spastic cerebral palsy was established successfully.The results of behavioral evaluation and MRI showed that the model was consis-tent with spastic hemiplegia. Key words: Macaque; Cerebral palsy; Animal model; Spastic cerebral palsy; Brain injury

Extratemporal resections in pediatric epilepsy surgery-an overview.

Despite optimized medical treatment, approximately one third of all patients with epilepsy continue to have seizures and by definition have medically resistant epilepsy (MRE). For these patients, surgical disruption of the epileptogenic network may enable freedom or great improvement in control of their seizures. The success of surgery is dependent on accurate localization of the epileptogenic zone and network. Epilepsy arising from regions of cortical dysplasia within the neocortex of the frontal, parietal, and occipital lobes show a propensity for reorganization and progressive decline in seizure freedom and consequent poorer surgical outcome. These procedures often require staged investigation with intracranial electrodes via subdural grids or stereoelectroencephalography (SEEG) and are considered extratemporal resections (ETRs). Central concepts include the following: (1) localization of epileptogenic and eloquent functional regions, (2) safe and effective placement of intracranial electrode arrays, (3) resection of epileptogenic cortex, and (4) avoidance of complications. Each of these concepts is summarized and developed in this summary paper.

Neuronavigated Fiber Dissection with Pial Preservation: Laboratory Model to Simulate Opercular Approaches to Insular Tumors

Advances in the oncologic and functional results of insular surgery have been reported recently. Such successes have been made possible by the advent of the transopercular approach under awake monitoring and by improved anatomic and functional knowledge of white matter pathways surrounding the insula. Nonetheless, given the rarity of insular tumors, it is difficult to get familiar with the complex 3-dimensional anatomy of the different neuronal and vascular structures encountered during a transopercular insular resection. We thus propose to develop a laboratory model allowing to train transopercular approaches of the insula. Two hemispheres prepared with Klinger's technique were dissected under light microscope, preserving all pial membranes. The different steps of the dissection were video recorded. Preservation of pial membranes enabled us to simulate subpial resection, both during operculum removal and during insular cortex resection. The medial wall of the resection was defined by the inferior-fronto-occipital fasciculus, protecting from the lenticulostriate arteries. In this paper, we show that Klinger dissection with preservation of pial membranes provides a realistic model of insular surgery, allowing surgeons to learn and train on this highly specialized surgery.

Prospective and “live” fast ripple detection and localization in the operating room: Impact on epilepsy surgery outcomes in children

ObjectiveFast ripples (FR, 250–500Hz) are proposed biomarkers of the epileptogenic zone on the basis of several retrospective reports linking postoperative seizure freedom to their complete resection. There are no clinical trials or prospective reports validating the use of FR as characterized by electrocorticography (ECoG), to guide the scope of epilepsy surgery, and to inform prognosis thereafter. We set out to prospectively evaluate the utility of FR resection to predict postoperative epilepsy outcomes, and examine the feasibility of “live” intraoperative FR ascertainment. MethodsFR were prospectively reviewed in 30 consecutive pediatric cases including 11 reviewed “live” during surgery. Intraoperative ECoG studies were recorded at 2000Hz sampling rate, interpreted conventionally to guide surgical resection, and visually inspected for FR. Seizure outcome was tallied for all 30 children. ResultsMedian age at surgery was 9.1 years (interquartile range [IQR] 4.7–13.2), median ECoG duration was 10.5min (IQR 8.0–13.2), and median postoperative follow-up was 58.4 months (IQR 25.7–79.0). FR were identified in 24 of 30 ECoG studies. The incomplete resection of FR was strongly linked to postoperative seizures (hazard ratio 11.6, p=0.005). “Live” ECoG review in the operating room to ascertain FR proved feasible and did not differ from conventional FR ascertainment. Significance:In a prospective fashion, including “live” review, FR were detected in 80% of pediatric ECoG studies, and incomplete resection of FR cortex predicted postoperative seizures. These findings extend the notion that interictal FR are surrogate markers of the epileptogenic zone, and that their intraoperative localization could be used to inform prognosis and guide surgical resections in children.