OBJECTIVE:Asymmetric temporal deformity is a common yet often underrecognized complication following craniofacial and neurosurgical procedures. The optimal method for its accurate characterization remains debated, with no universally accepted standard. This study aimed to assess subjective perceptions of temporal asymmetry among professionals and laypersons, objectively evaluate temporal asymmetry using morphometric techniques, and examine whether subjective and objective evaluations correlate. METHODS:This cross-sectional study included magnetic resonance imaging-derived 3-dimensional craniofacial images from 64 adults who underwent a pretemporal approach for the surgical treatment of drug-resistant temporal lobe epilepsy at a tertiary-level multidisciplinary epilepsy center. Temporal asymmetry was evaluated using a 4-point Likert scale by professionals (n = 36) and laypersons (n = 40), based on preoperative and 12-month postoperative frontal images. Subjective ratings were correlated with objective morphometric parameters commonly used to quantify temporal asymmetry-specifically, automatically computed differences in volume (cm³) and contour area (cm²) between the left and right temporal regions. Higher subjective scores and objective values indicated greater asymmetry. RESULTS:Postoperative temporal asymmetry significantly increased (all P <0.001) in volume (from 27.73±8.87 to 55.30±30.13 cm³), contour (from 6.63±2.27 to 13.95±8.23 cm²), and subjective scores (from 1.30±0.22 to 2.20±0.70). Professional and lay scores did not differ significantly (all P >0.05), and both panels showed moderate-to-strong positive correlations ( rho = 0.43-0.83; all P <0.001) with volume and contour measures, regardless of surgical status. CONCLUSIONS:Professional and lay raters demonstrated comparable perceptions of temporal asymmetry, which showed varying correlation with objective measures.

Background:Resective surgery through pterional approach is an effective treatment for drug-resistant temporal lobe epilepsy, but it may lead to temporal asymmetry in the craniofacial region. Nonetheless, recent systematic reviews showed that there is no gold standard method for the discrimination of a clinically visible abnormal temporal asymmetry from a normal fluctuating asymmetry. This study compares the ability of trained and untrained observers to detect temporal asymmetry and establishes a threshold for clinically detecting abnormal asymmetry. Methods:Standardized magnetic resonance imaging (MRI)-derived three-dimensional (3D) frontal views of adult patients who underwent temporal lobe epilepsy surgery were used to create a continuum spectrum of preoperative (n = 96) and 12-month postoperative (n = 96) craniofacial images. A panel of 32 untrained lay observers (family members and laypeople) and 32 trained clinicians (surgeons and clinical specialists) independently appraised randomly displayed 3D craniofacial soft-tissue images to assess the presence or absence of temporal asymmetry. Objective linear quantifications of temporal thickness differences were obtained from each preoperative and postoperative MRI scan to identify a potential threshold for subjective asymmetry detection. Temporal asymmetry was further categorized into severity levels I to IV based on incremental asymmetry values. Results:The temporal thickness difference was significantly (P < 0.001) greater in postoperative images (18.3% ± 9.6%) compared to preoperative images (4.6% ± 1.9%). As temporal asymmetry increased from Level I to IV, a significantly higher proportion of 3D craniofacial images were perceived as asymmetrical by all observer categories (P < 0.001). Both trained clinicians and untrained observers-including surgeons, clinical specialists, family members, and laypeople-demonstrated increased (P < 0.001) detection rates with increasing asymmetry severity. A temporal thickness difference exceeding 10% was clinically detected with over 90% accuracy across all observer categories (P < 0.001), establishing a 10% threshold for the clinical perception of temporal asymmetry.

We aim to report the epidemiology, surgical outcomes, and survival rates of pediatric patients with posterior fossa tumors in a large single-center case series. A retrospective analysis was conducted on pediatric patients who underwent surgical treatment for posterior fossa tumors between January 2011 and January 2019. A total of 135 pediatric patients, with an average age of 7.5 years at diagnosis and a mean follow-up of 35.7 months, were included in the study. Most tumors were located within the midline, with ventriculomegaly observed in 71.4

Background: Diffuse gliomas are common primary tumors of the central nervous system. The current diagnosis of such lesions, which include astrocytomas, depends on molecular features, including the presence of mutation in the enzyme isocitrate dehydrogenase(IDH). The wild isoforms of IDH-1(cytosolic) and 2(mitochondrial) convert isocitrate into α-ketoglutarate(αCG), promoting the reduction of NADP+ to NADPH. Both αCG and NADPH are antioxidants. The most common mutant form of IDH1(R132H) has a gain of function in which αCG is converted into D2-hydroxyglutarate, an oncogenic compound that consumes NADPH. Thus, a functional relationship is observed between IDH1, IDH2 and IDH1R132H. Objective: To perform neuropathological characterization of diffuse astrocytomas in adults as well as to investigate the immunostaining and possible alteration in tissue distribution of IDH1, IDH2 and IDH1R132H, considering the presence of the R132H mutation and histological grade. Methods: We evaluated 25 surgical specimens from adults with diffuse gliomas, which were molecularly and immunophenotypically characterized as astrocytomas of low- or high-grade (2 (n=10) or 4 (n=15), respectively), according to the World Health Organization current criteria. We also analyzed the immunostaining pattern of IDH1, IDH2 and IDH1R132H, as well as their tissue distribution (mean % of positivity assessed by using ImageJ® software), considering the R132H mutation and the lesion histological grade. Results: Regarding age at diagnosis(< or ≥55 years) and R132H immunopositivity, the lesions were classified as: astrocytoma, IDH-mutant, grade 2 (5/25); astrocytoma, not otherwise specified (NOS), grade 2 (5/25); glioblastoma, IDH-wildtype, grade 4 (9/25) or astrocytoma, NOS, grade 4 (6/25). IDH1, IDH2 and IDH1R132H showed a diffuse cytoplasmic staining pattern, regardless of grade. When comparing low- and high-grade lesions, the tissue distribution of IDH1 was lower in the former (14.20±1.70% and 16.40±1.60%, respectively; p=0.0051), no difference being observed for IDH2 (15.10±1.80% and 14.90±2.0%; p=0.6773) and R132H (5.20±5.60% and 1.80±4.80%; p=0.1234). Specifically, low-grade lesions with (5/10) or without (5/10) the mutation showed no differences regarding tissue distribution of IDH1 (14.40±2.30% and 14.10±0.90%, respectively; p=0.2963) or IDH2(15.60±1.0% and 14.70±2.40%; p=0.8345). Irrespective of the histological grade, there was correlation neither between tissue expressions of R132H and IDH1 nor between R132H and IDH2. Conclusion: In the present series, IDH1R132H was more frequent in grade 2 than in grade 4 lesions. Furthermore, our data suggest that (1) such mutation does not interfere with tissue expression of wild-type IDH1 and IDH2, and (2) the wild-type IDH1 allele would ensure protein synthesis at physiological levels.

Focal Cortical Dysplasia (FCD) is a neurodevelopmental condition characterized by malformations of the cerebral cortex that often cause drug-resistant epilepsy. In this study, we performed multi-omics single-nuclei profiling to map the chromatin accessibility and transcriptome landscapes of FCD type II, generating a comprehensive multimodal single-nuclei dataset comprising 61,525 cells from 11 clinical samples of lesions and controls. Our findings revealed profound chromatin, transcriptomic, and cellular alterations affecting neuronal and glial cells in FCD lesions, including the selective loss of upper-layer excitatory neurons, significant expansion of oligodendrocytes and immature astrocytic populations, and a distinct neuronal subpopulation harboring dysmorphic neurons. Furthermore, we uncovered activated microglia subsets, particularly in FCD IIb cases. This comprehensive study unveils neuronal and glial cell states driving FCD development and epileptogenicity, enhancing our understanding of FCD and offering directions for targeted therapy development.

Focal cortical dysplasia (FCD) is a brain malformation that causes medically refractory epilepsy. FCD is classified into three categories based on structural and cellular abnormalities, with FCD type II being the most common and characterized by disrupted organization of the cortex and abnormal neuronal development. In this study, we employed cell-type deconvolution and single-cell signatures to analyze bulk RNA-seq from multiple transcriptomic studies, aiming to characterize the cellular composition of brain lesions in patients with FCD IIa and IIb subtypes. Our deconvolution analyses revealed specific cellular changes in FCD IIb, including neuronal loss and an increase in reactive astrocytes (astrogliosis) when compared to FCD IIa. Astrogliosis in FCD IIb was further supported by a gene signature analysis and histologically confirmed by glial fibrillary acidic protein (GFAP) immunostaining. Overall, our findings demonstrate that FCD II subtypes exhibit differential neuronal and glial compositions, with astrogliosis emerging as a hallmark of FCD IIb. These observations, validated in independent patient cohorts and confirmed using immunohistochemistry, offer novel insights into the involvement of glial cells in FCD type II pathophysiology and may contribute to the development of targeted therapies for this condition.

Mesial temporal lobe epilepsy is the most frequent type of focal epilepsy in young adults and the most commonly reported in surgical series worldwide.1,2 When seizures become refractory to drug therapy, they are unlikely to remit spontaneously, and for the 30% of patients with epilepsy that is refractory to antiepileptic drugs, resection of the mesial temporal lobe structures provides seizure control rates of 70%-80%.3,4 The transsylvian route for amygdalohippocampectomy has been used at our institution for many years, evolving from the first description of Yasargil through the inferior circular sulcus of insula to the most recent one through the amygdala trying to preserve the temporal stem.5,6 Despite good outcomes according to the Engel classification, analysis of late postoperative magnetic resonance imaging scans of our patients showed a high incidence of temporal pole atrophy and potential gliosis.7,8 Therefore, we decided to keep the transsylvian route, but we removed a portion of the temporal pole anterior to the limen insula, resulting in a temporopolar amygdalohippocampectomy.4,9 Temporopolar amygdalohippocampectomy demonstrated good temporal stem preservation, good visual outcomes, and good memory results.4 We also advocate that the transsylvian route has the potential to provide a superior view and resection of the piriform cortex, that is associated with seizure outcome after surgery.10 We present a case of a 42-year-old woman who had refractory seizures secondary to mesial temporal lobe epilepsy and underwent temporopolar amygdalohippocampectomy with a good outcome, remaining seizure-free (Engel IA) (Video 1). The patient provided consent for surgery and video publication.

Introduction Focal cortical dysplasia (FCD) is a common cause of pharmacoresistant epilepsy. According to the 2022 International League Against Epilepsy classification, FCD type II is characterized by dysmorphic neurons (IIa and IIb) and may be associated with balloon cells (IIb). We present a multicentric study to evaluate the transcriptomes of the gray and white matters of surgical FCD type II specimens. We aimed to contribute to pathophysiology and tissue characterization. Methods We investigated FCD II (a and b) and control samples by performing RNA-sequencing followed by immunohistochemical validation employing digital analyses. Results We found 342 and 399 transcripts differentially expressed in the gray matter of IIa and IIb lesions compared to controls, respectively. Cholesterol biosynthesis was among the main enriched cellular pathways in both IIa and IIb gray matter. Particularly, the genes HMGCS1, HMGCR, and SQLE were upregulated in both type II groups. We also found 12 differentially expressed genes when comparing transcriptomes of IIa and IIb lesions. Only 1 transcript (MTRNR2L12) was significantly upregulated in FCD IIa. The white matter in IIa and IIb lesions showed 2 and 24 transcripts differentially expressed, respectively, compared to controls. No enriched cellular pathways were detected. GPNMB, not previously described in FCD samples, was upregulated in IIb compared to IIa and control groups. Upregulations of cholesterol biosynthesis enzymes and GPNMB genes in FCD groups were immunohistochemically validated. Such enzymes were mainly detected in both dysmorphic and normal neurons, whereas GPNMB was observed only in balloon cells. Discussion Overall, our study contributed to identifying cortical enrichment of cholesterol biosynthesis in FCD type II, which may correspond to a neuroprotective response to seizures. Moreover, specific analyses in either the gray or the white matter revealed upregulations of MTRNR2L12 and GPNMB, which might be potential neuropathological biomarkers of a cortex chronically exposed to seizures and of balloon cells, respectively.

Traumatic atlanto-occipital dislocation (TAOD) are uncommon injuries associated with high immediate mortality rate and occurs more than twice in children than adults, due to biomechanical properties and immaturity of children's cervical spine. We report a pediatric patient with TAOD, who underwent occipitocervical stabilization and also developed a late hydrocephalus requiring a shunt procedure. A six-year-old boy was admitted to the emergency department after a car accident with refractory cervical pain. A cervical computed tomography (CT) scan showed an anterior C1–C2 level hematoma, and a dynamic CT scan demonstrated an increasing basion-dens interval on extension. Cervical magnetic resonance imaging (MRI) showed discontinuity of the tectorial membrane and diffused hyperintense signal on the left alar ligament. These findings were attributed to TAOD, and an occipitocervical fusion was performed. The pain and neurological status improved after surgery, but after 3 months he returned with persistent vomiting, headache, and a CT scan showing hydrocephalus. Then, a ventriculoperitoneal shunt was performed, improving the symptoms. One year after the injury, the patient remained asymptomatic, and a later radiography demonstrated satisfactory bone fusion. In conclusion, the decision-making process regarding treatment should consider several clinical and radiographic findings. Occipitocervical fusion is the treatment of choice, while hydrocephalus is not an unusual complication in children.

ABSTRACT Background: The correlation between angioarchitecture and clinical presentation of brain arteriovenous malformation (bAVM) remains a subject of debate. Objective: The main purpose of the present study was to assess the correlation between angioarchitectural characteristics of bAVM and clinical presentation. Methods: A retrospective review of all consecutive patients presenting a bAVM who underwent a cerebral angiography at Beneficencia Portuguesa Hospital in São Paulo between January 2006 and October 2016 was carried out. Patients were divided in five groups: group 1 - hemorrhage; group 2 - seizure; group 3 - headache; group 4 - progressive neurological deficits (PND); group 5 - incidental). Results: A total of 183 patients were included, with group 1 comprising 56 cases, group 2 49 cases, group 3 41 cases, group 4 28 cases, and group 5 9 cases. Regarding hemorrhage presentation, a statistical correlation was observed with female gender (P < 0.02), Spetzler-Martin 3B (P < .0015), and lesions with low flow (P < 0.04). A positive association was found between group 2 and age less than 36 years (P < 0.001), male sex (P < 0.018), presence of superficial lesions not classified as SM 3B (P < 0.002), presence of venous ectasia (p <0.03), and arterial steal phenomenon (P < 0.03). Group 4 was associated with older age (P < 0.01). Conclusions: Angioarchitectural characteristics can be correlated with some clinical presentations as well as with some clinical data, making it possible to create predictive models to differentiate clinical presentations.

Major histocompatibility complex class I (MHC-I) has been implicated in several types of neuroplasticity phenomena. Interferon beta-1b (IFN-β) increases MHC-I expression by motoneurons after sciatic nerve crush in mice, improving axonal growth and functional recovery. Additionally, IFN-β induces glial hypertrophy associated with upregulation of glial fibrillary acidic protein (GFAP) and MHC-I in murine astrocytes in vitro. As knowledge about MHC-I and its role in synaptic plasticity in human astrocytes (HAs) is scarce, we investigated these aspects in mature HAs obtained from the neocortex of patients undergoing surgery due to hippocampal sclerosis. Cells were exposed to media in the absence (0 IU/ml) or presence of IFN-β for 5 days (500 IU/ml). Beta-2 microglobulin (β2m), a component of the MHC-I, GFAP and vimentin proteins, was quantified by flow cytometry (FC) and increased by 100%, 60% and 46%, respectively, after IFN-β exposure. We also performed qRT–PCR gene expression analyses for β2m, GFAP, vimentin, and pro- and anti-inflammatory cytokines. Our data showed that IFN-β-treated astrocytes displayed β2m and GFAP gene upregulation. Additionally, they presented a proinflammatory profile with increase in the IL-6 and IL-1β genes and a tendency to upregulate TNF-α. Moreover, we evaluated the effect of HAs conditioned medium (CM) on the formation/maintenance of neurites/synapses by the PC12 lineage. Synaptophysin protein expression was quantified by FC. The CM of IFN-β-activated astrocytes was not harmful to PC12 neurites, and there was no change in synaptophysin protein expression. Therefore, IFN-β activated HAs by increasing GFAP, vimentin and MHC-I protein expression. Like MHC-I modulation and astrocyte activation may be protective after peripheral nerve damage and in some neurodegenerative conditions, this study opens perspectives on the pathophysiological roles of astroglial MHC-I in the human CNS.

Most patients with pharmacoresistant mesial temporal lobe epilepsy (MTLE) have hippocampal sclerosis on the postoperative histopathological examination. Although most patients with MTLE do not refer to a family history of the disease, familial forms of MTLE have been reported. We studied surgical specimens from patients with MTLE who had epilepsy surgery for medically intractable seizures. We assessed and compared gene expression profiles of the tissue lesion found in patients with familial MTLE ( n = 3) and sporadic MTLE ( n = 5). In addition, we used data from control hippocampi obtained from a public database ( n = 7). We obtained expression profiles using the Human Genome U133 Plus 2.0 (Affymetrix) microarray platform. Overall, the molecular profile identified in familial MTLE differed from that in sporadic MTLE. In the tissue of patients with familial MTLE, we found an over-representation of the biological pathways related to protein response, mRNA processing, and synaptic plasticity and function. In sporadic MTLE, the gene expression profile suggests that the inflammatory response is highly activated. In addition, we found enrichment of gene sets involved in inflammatory cytokines and mediators and chemokine receptor pathways in both groups. However, in sporadic MTLE, we also found enrichment of epidermal growth factor signaling, prostaglandin synthesis and regulation, and microglia pathogen phagocytosis pathways. Furthermore, based on the gene expression signatures, we identified different potential compounds to treat patients with familial and sporadic MTLE. To our knowledge, this is the first study assessing the mRNA profile in surgical tissue obtained from patients with familial MTLE and comparing it with sporadic MTLE. Our results clearly show that, despite phenotypic similarities, both forms of MTLE present distinct molecular signatures, thus suggesting different underlying molecular mechanisms that may require distinct therapeutic approaches.

This is a surgical technique video of a right peri-insular hemispherotomy in a child with Rasmussen’s encephalitis. The patient is a 5-year-old boy with focal onset impaired awareness seizures started 6 months before surgery, developing different subtypes of focal seizures and evolving to drug-resistant epilepsy. In neurological examination, he already had a left-sided hemiparesis with pyramidal signs. Magnetic resonance imaging showed right-sided cortical atrophy and fronto-insular subcortical hyperintensity signal areas. The preoperative electroencephalogram revealed frequent right-sided central mid temporal spikes. The history and complementary exams raised a hypothesis of Rasmussen’s encephalitis, a rare neurological condition, characterized by unilateral chronic inflammation of the cerebral cortex, causing drug-resistant epilepsy, and evolving to progressive neurological decline1. The hemispherotomy is an effective procedure aimed to isolate the entire hemisphere functionally with minimal removal of brain tissue, and remains the only cure for seizures caused by Rasmussen’s encephalitis2,3. Long-term seizure freedom may be achieved in around 80% of patients and improves quality of life4. It’s already accepted that briefer duration of epilepsy preceding the surgery is associated to better adaptive functioning postoperatively due to the high neuroplasticity of young patients4. Three years after surgery, the patient remains seizure free, walking without help.

OBJECTIVES:We compared the proteomic signatures of the hippocampal lesion induced in three different animal models of mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE+HS): the systemic pilocarpine model (PILO), the intracerebroventricular kainic acid model (KA), and the perforant pathway stimulation model (PPS).METHODS:We used shotgun proteomics to analyze the proteomes and find enriched biological pathways of the dorsal and ventral dentate gyrus (DG) isolated from the hippocampi of the three animal models. We also compared the proteomes obtained in the animal models to that from the DG of patients with pharmacoresistant MTLE+HS.RESULTS:We found that each animal model presents specific profiles of proteomic changes. The PILO model showed responses predominantly related to neuronal excitatory imbalance. The KA model revealed alterations mainly in synaptic activity. The PPS model displayed abnormalities in metabolism and oxidative stress. We also identified common biological pathways enriched in all three models, such as inflammation and immune response, which were also observed in tissue from patients. However, none of the models could recapitulate the profile of molecular changes observed in tissue from patients.SIGNIFICANCE:Our results indicate that each model has its own set of biological responses leading to epilepsy. Thus, it seems that only using a combination of the three models may one replicate more closely the mechanisms underlying MTLE+HS as seen in patients.

Focal cortical dysplasia is a highly epileptogenic cortical malformation with few treatment options. Here, we generated human cortical organoids from patients with focal cortical dysplasia type II. Using this human model, we mimicked some focal cortical dysplasia hallmarks, such as impaired cell proliferation, the presence of dysmorphic neurons and balloon cells, and neuronal network hyperexcitability. Furthermore, we observed alterations in the adherens junctions zonula occludens-1 and partitioning defective 3, reduced polarization of the actin cytoskeleton, and fewer synaptic puncta. Focal cortical dysplasia cortical organoids showed downregulation of the small GTPase RHOA, a finding that was confirmed in brain tissue resected from these patients. Functionally, both spontaneous and optogenetically-evoked electrical activity revealed hyperexcitability and enhanced network connectivity in focal cortical dysplasia organoids. Taken together, our findings suggest a ventricular zone instability in tissue cohesion of neuroepithelial cells, leading to a maturational arrest of progenitors or newborn neurons, which may predispose to cellular and functional immaturity and compromise the formation of neural networks in focal cortical dysplasia.

Abstract INTRODUCTION: Infratentorial tumors represent 45 to 60% of all brain tumors in children and are associated with hydrocephalus in 70 to 90% of cases. The aim of this study is to describe and analyze the surgical results and correlate them with the incidence of hydrocephalus, as well as identify predictive factors of hydrocephalus in patients underwent to a surgical treatment of posterior fossa tumors. METHODS: This is a retrospective observational study, based on demographic, clinical and radiological information of pediatric patients underwent to surgical resection of posterior fossa tumors by a single group between 2011 and 2019. RESULTS: We included 135 patients with a mean age of 7.56 years, mean follow-up of 35.7 months and overall survival of 18.8 months. Considering the histology, most tumors were pilocytic astrocytomas (34.1%), followed by medulloblastomas (27.4%) Total resection was achieved in 77.8% and tumor recurrence was observed in 16.2%. The rate of hydrocephalus was 36.3%, with most shunt procedures performed preoperatively. There was a high rate of complications associated with shunting (42.9%), mostly represented by infection (71.5%). Patients with hydrocephalus were younger (p = 0.001), showing a faster evolution between the onset of symptoms and diagnosis (p = 0.008). Tumor volume (p = 0.1) and location (p = 0.32) were not statistically significant for hydrocephalus, however, the presence of leptomeningeal disease (p = 0.001) was. The resection rate was also significant, with lesions totally resected showing the best results (p = 0.009). Regarding tumor histology, 33.3% of patients with medulloblastoma and 62.5% of patients with ependymoma were shunted. CONCLUSION: One third of children with posterior fossa tumors will require a shunt procedure. Some factors should guide the neurosurgeon during patient counseling and surgical planning to minimize the use of permanent shunts and avoid related complications.

Hippocampal sclerosis (HS) is a common cause of pharmacoresistant focal epilepsy. Here, we (1) performed a histological approach to the anterior temporal pole of patients with HS to evaluate cortical and white matter (WM) cell populations, alteration of myelin integrity and markers of neuronal activity, and (2) correlated microscopic data with magnetic resonance imaging (MRI) findings. Our aim was to contribute with the understanding of neuroimaging and pathophysiological mechanisms of temporal lobe epilepsy (TLE) associated with HS. We examined MRIs and surgical specimens from the anterior temporal pole from TLE-HS patients (n = 9) and compared them with 10 autopsy controls. MRIs from healthy volunteers (n = 13) were used as neuroimaging controls. Histological techniques were performed to assess oligodendrocytes, heterotopic neurons, cellular proliferative index, and myeloarchitecture integrity of the WM, as well as markers of acute (c-fos) and chronic (ΔFosB) activities of neocortical neurons. Microscopic data were compared with neuroimaging findings, including T2-weighted/FLAIR MRI temporopolar blurring and values of fractional anisotropy (FA) from diffusion-weighed imaging (DWI). We found a significant increase in WM oligodendrocyte number, both in hematoxylin and eosin, and in Olig2-stained sections. The frequencies of oligodendrocytes in perivascular spaces and around heterotopic neurons were significantly higher in patients with TLE–HS compared with controls. The percentage of 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase; a marker of myeloarchitecture integrity) immunopositive area in the WM was significantly higher in TLE-HS, as well as the numbers of c-fos- and ΔFosB-immunostained neocortical neurons. Additionally, we demonstrated a decrease in axonal bundle integrity on neuroimaging, with a significant reduction in the FA in the anterior temporal pole. No differences were detected between individuals with and without temporopolar blurring on visual MRI analysis, considering the number of oligodendroglial cells and percentage of WM CNPase-positive areas. Also, there was no relationship between T2 relaxometry and oligodendrocyte count. In conclusion, our histopathological data support the following: (1) the hypothesis that repetitive neocortical neuronal activity could induce changes in the WM cellular constitution and myelin remodeling in the anterior temporal pole from patients with TLE-HS, (2) that oligodendroglial hyperplasia is not related to temporal blurring or T2 signal intensity on MRI, and (3) that reduced FA is a marker of increase in Olig2-immunopositive cells in superficial temporopolar WM from patients with TLE-HS.

Objective: This study's objective was to compare the transinsular (TI-AH), transuncus (TU-AH), and temporopolar (TP-AH) amygdalohippocampectomy approaches regarding seizure control, temporal stem (TS) damage, and neurocognitive decline. Methods: We included 114 consecutive patients with unilateral hippocampal sclerosis (HS) who underwent TI-AH, TU-AH, or TP-AH between 2002 and 2017. We evaluated seizure control using Engel classification. We used diffusion tensor imaging and postoperative Humphrey perimetry to assess the damage of the TS. We also performed pre- and postoperative memory performance and intelligence quotient (IQ). Results: There were no significant differences in the proportion of patients free of disabling seizures (Engel IA+IB) among the three surgical approaches in the survival analysis. However, more patients were free of disabling seizures (Engel IA+IB) at 2 years of postsurgical follow-up with TP-AH (69.5%) and TI-AH (76.7%) as compared to the TU-AH (43.5%) approach (p = .03). The number of fibers of the inferior fronto-occipital fasciculus postoperatively was reduced in the TI-AH group compared with the TU-AH and TP-AH groups (p = .001). The rate of visual field defects was significantly higher with TI-AH (14/19, 74%) in comparison to the TU-AH (5/15, 33%) and TP-AH (13/40, 32.5%) approaches (p = .008). Finally, there was a significant postoperative decline in verbal memory in left-sided surgeries (p = .019) and delayed recall for both sides (p < .001) regardless of the surgical approach. However, TP-AH was the only group that showed a significant improvement in visual memory (p < .001) and IQ (p < .001) for both right- and left-sided surgeries. Significance: The TP-AH group had better short-term seizure control than TU-AH, a lower rate of visual field defects than TI-AH, and improved visual memory and IQ compared to the other groups. Our findings suggest that TP-AH is a better surgical approach for temporal lobe epilepsy with HS than TI-AH and TU-AH.

We aimed to better characterize the magnetic resonance imaging (MRI) findings of mild malformation of cortical development with oligodendroglial hyperplasia (MOGHE), a rare clinicopathological entity associated with pharmacoresistance recently described in patients with frontal lobe epilepsy.