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Neuroimaging, neuropsychological, and psychophysical evidence indicates that concept retrieval selectively engages specific sensory and motor brain systems involved in the acquisition of the retrieved concept. However, it remains unclear which supramodal cortical regions contribute to this process and what kind of information they represent. Here, we used representational similarity analysis of two large fMRI data sets, with a searchlight approach, to generate a detailed map of human brain regions where the semantic similarity structure across individual lexical concepts can be reliably detected. We hypothesized that heteromodal cortical areas typically associated with the “default mode network” encode multimodal experiential information about concepts, consistent with their proposed role as cortical integration hubs. In two studies involving different sets of concepts and different participants (both sexes), we found a distributed, bihemispheric network engaged in concept representation, composed of high-level association areas in the anterior, lateral, and ventral temporal lobe; inferior parietal lobule; posterior cingulate gyrus and precuneus; and medial, dorsal, ventrolateral, and orbital prefrontal cortex. In both studies, a multimodal model combining sensory, motor, affective, and other types of experiential information explained significant variance in the neural similarity structure observed in these regions that was not explained by unimodal experiential models or by distributional semantics (i.e., word2vec similarity). These results indicate that, during concept retrieval, lexical concepts are represented across a vast expanse of high-level cortical regions, especially in the areas that make up the default mode network, and that these regions encode multimodal experiential information.Significance StatementConceptual knowledge includes information acquired through various modalities of experience, such as visual, auditory, tactile, and emotional information. We investigated which brain regions encode mental representations that combine information from multiple modalities when participants think about the meaning of a word. We found that such representations are encoded across a widely distributed network of cortical areas in both hemispheres, including temporal, parietal, limbic, and prefrontal association areas. Several areas not traditionally associated with semantic cognition were also implicated. Our results indicate that the retrieval of conceptual knowledge during word comprehension relies on a much larger portion of the cerebral cortex than previously thought, and that multimodal experiential information is represented throughout the entire network.

Background Theta burst stimulation (TBS), a patterned repetitive transcranial magnetic stimulation (rTMS) protocol with shorter simulation duration and lower stimulus intensity, could be a better protocol for individuals with autism spectrum disorder (ASD). Our study aimed to explore the impacts of intermittent TBS (iTBS) over the bilateral posterior superior temporal sulcus (pSTS) on intellectually able adults with ASD. Material and methods In this randomized, single-blinded, sham-controlled crossover trial, 13 adults with ASD completed iTBS for 5 consecutive days over the bilateral pSTS and inion (as a sham control) in a 16-weeks interval and in a randomly assigned order. The neuropsychological function was measured with the Wisconsin Card Sorting Test (WCST) for cognitive flexibility while the clinical outcomes were measured with both self-rate and parents-rate Autism Spectrum Quotient (AQ) before and after 5-day iTBS interventions. Results The results revealed significantly immediate effects of multi-session iTBS over the bilateral pSTS on parent-rate autistic symptoms in adults with ASD. The post-hoc analysis revealed the impacts of multi-session iTBS on cognitive flexibility were affected by baseline social-communicative impairment and baseline cognitive performance. Besides, the impacts of multi-session iTBS on clinical symptoms was affected by the concurrent psychotropic medication use and baseline autistic symptoms. Conclusions Given the caveat of the small sample size and discrepancy of multiple informants, this pilot study suggests the therapeutic potential of 5-day multi-session iTBS over the pSTS in adults with ASD. Individual factors modulating the response to rTMS should be explicitly considered in the future trial.

OBJECTIVE Tailored surgery to extensively resect epileptogenic lesions using intraoperative electrocorticography (ioECoG) may improve seizure outcomes. However, resection of large areas is associated with decreased memory function postoperatively. The authors assessed whether ioECoG could provide useful information on how to minimize the focus resection and obtain better seizure outcomes without memory deterioration. They examined the postoperative seizure-free period and memory alteration in a retrospective cohort of patients with mesial temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS) in whom the extent of removal was determined using ioECoG findings. METHODS The authors enrolled 82 patients with TLE associated with HS who were treated surgically. Transsylvian amygdalohippocampectomy was indicated as the first step. When visual inspection identified interictal epileptic discharges from the lateral temporal lobe on ioECoG, anterior temporal lobectomy (ATL) was eventually performed. The patients were divided into the selective amygdalohippocampectomy (SA, n = 40) and ATL (n = 42) groups. Postoperative seizure outcomes were assessed at 1, 2, 3, 5, and 7 years postoperatively using the International League Against Epilepsy classification. The Kaplan-Meier survival analysis was applied to evaluate the period of seizure recurrence between the SA and ATL groups. Factors attributed to seizure recurrence were analyzed using the Cox proportional hazards model, and they were as follows: epileptic focal laterality; age at seizure onset (< 10 or ≥ 10 years old); seizure frequency (more than weekly or less than weekly seizures); history of focal to bilateral tonic-clonic seizure; infectious etiology; and surgical procedure. The Wechsler Memory Scale–Revised was used to evaluate memory function pre- and postoperatively. RESULTS Seizure outcomes were significantly worse in the SA group than in the ATL group at 2 years postoperatively (p = 0.045). The International League Against Epilepsy class 1 outcomes at 7 years postoperatively in the SA and ATL groups were 63% and 81%, respectively. Kaplan-Meier analysis showed that seizure recurred significantly earlier in the SA group than in the ATL group (p = 0.031). The 2-way ANOVA analysis was used to compare the SA and ATL groups in each memory category, and revealed that there was no significant difference regardless of the side of surgery. CONCLUSIONS Visual assessment of ioECoG cannot be used as an indicator to minimize epileptic focus resection in patients with TLE associated with HS. ATL is more effective in obtaining seizure-free outcomes; however, both ATL and SA can preserve memory function.

Introduction: Electrophysiological and neuroimaging studies have demonstrated that large-scale brain networks are affected during the development of epilepsy. These networks can be investigated by using diffusion magnetic resonance imaging (dMRI). The most commonly used model to analyze dMRI is diffusion tensor imaging (DTI). However, DTI metrics are not specific to microstructure or pathology and the DTI model does not take into account crossing fibers, which may lead to erroneous results. To overcome these limitations, a more advanced model based on multi-shell multi-tissue constrained spherical deconvolution was used in this study to perform tractography with more precise fiber orientation estimates and to assess changes in intra-axonal volume by using fixel-based analysis. Methods: dMRI images were acquired before and at several time points after induction of status epilepticus in the intraperitoneal kainic acid (IPKA) rat model of temporal lobe epilepsy. Tractography was performed, and fixel metrics were calculated in several white matter tracts. The tractogram was analyzed by using the graph theory. Results: Global degree, global and local efficiency were decreased in IPKA animals compared with controls during epileptogenesis. Nodal degree was decreased in the limbic system and default-mode network, mainly during early epileptogenesis. Further, fiber density (FD) and fiber-density-and-cross-section (FDC) were decreased in several white matter tracts. Discussion: These results indicate a decrease in overall structural connectivity, integration, and segregation and decreased structural connectivity in the limbic system and default-mode network. Decreased FD and FDC point to a decrease in intra-axonal volume fraction during epileptogenesis, which may be related to neuronal degeneration and gliosis. Impact statement To the best of our knowledge, this is the first longitudinal multi-shell diffusion magnetic resonance imaging study that combines whole-brain tractography and fixel-based analysis to investigate changes in structural brain connectivity and white matter integrity during epileptogenesis in a rat model of temporal lobe epilepsy. Our findings present better insights into how the topology of the structural brain network changes during epileptogenesis and how these changes are related to white matter integrity. This could improve the understanding of the basic mechanisms of epilepsy and aid the rational development of imaging biomarkers and epilepsy therapies.

We evaluated a 39-year-old pregnant woman with right temporal lobe epilepsy. During the second trimester, seizure deterioration was responsive to an increased daily dose of levetiracetam (LEV). However, immediately after delivery, new non-habitual seizures emerged along with a sharply increased LEV concentration. The frequency of habitual seizures also slightly increased. The non-habitual seizures completely disappeared, and the frequency of the habitual seizures improved to the baseline level after the LEV dosage was reduced. Thus, a paradoxical effect of an increased LEV blood concentration was assumed to be a potential cause of these events. Peripartum pharmacokinetic fluctuations in LEV levels should be monitored carefully.

Objective The investigators aimed to explore the clinical characteristics, immunotherapy, and outcomes of patients with antileucine-rich glioma-inactivated-1 (anti-LGI1) encephalitis. Methods Data on participants' clinical characteristics, laboratory findings, radiological and electroencephalogram (EEG) features, treatment, and outcomes from January 2012 to December 2016 were collected. Statistical analysis was conducted to assess the factors associated with patient functional outcome. Forty-three patients were enrolled in the study, with a predominance of males (65.1%). The median age at onset was 57 years (interquartile range [IQR]: 44.0-65.0). The median time from onset to diagnosis was 60 days (IQR: 37.0-127.0). Results The main clinical manifestations included epilepsy (100%), faciobrachial dystonic seizures (FBDS; 44.2%), cognitive dysfunction (95.3%), neuropsychiatric disturbances (76.7%), sleep disorders (58.1%), and disturbance of consciousness (48.8%). Twenty-two patients (51.2%) had hyponatremia, 31 (72.1%) had abnormal EEG results, and 30 (69.8%) had abnormal brain MRI scans, mainly involving the hippocampus (76.7%) or temporal lobe (40%). Twenty of 34 patients (58.8%) in a follow-up MRI examination exhibited hippocampal atrophy. Twenty-five patients (58.2%) were administered corticosteroids and intravenous immunoglobulin, whereas 17 patients were treated only with corticosteroids. Forty-one patients (95.3%) had favorable outcomes after a median of 21.5 months (IQR: 7-43) of follow-up. Serum sodium level was a factor associated with a disabled status (odds ratio=0.81, 95% CI=0.66, 0.98, p=0.03). Anti-LGI1 encephalitis patients were characterized by seizures, FBDS, cognitive deficits, neuropsychiatric disturbances, and hyponatremia. Conclusions Most patients with anti-LGI1 encephalitis are nonparaneoplastic, have low recurrence rates, and have favorable prognostic outcomes. Rapid evaluation, prompt immunotherapy, and long-term follow-up are essential in the care of anti-LGI1 encephalitis patients.

OBJECTIVE Changes of dream ability and content in patients with brain lesions have been addressed in only about 100 case reports. All of these reports lack data regarding prelesional baseline dream content. Therefore, it was the objective of this study to prospectively assess dream content before and after anterior temporal lobectomy. METHODS Using the Hall and Van de Castle system, 30 dreams before and 21 dreams after anterior temporal lobectomy for drug-resistant epilepsy were analyzed. Fifty-five dreams before and 60 dreams after stereoelectroencephalography served as controls. RESULTS After anterior temporal lobectomy, patients had significantly less physical aggression in their dreams than preoperatively (p < 0.01, Cohen’s h statistic). Dream content of patients undergoing stereoelectroencephalography showed no significant changes. CONCLUSIONS Within the default dream network, the temporal lobe may account for aggressive dream content. Impact of general anesthesia on dream content, as a possible confounder, was ruled out.

Rationale and Objective To investigate age-related brain morphological changes of boys with high functioning autism (HFA). Materials and Methods Forty-six medication-naive boys with HFA and 48 age-matched typically developing boys (4–12 years old) were included in this study. Structural brain images were processed with FreeSurfer to calculate the brain morphometric features including regional volume, surface area, average cortical thickness, and Gaussian curvature. General linear model was used to identify significant effects of diagnosis and age-by-diagnosis interaction. Correlations between age and the brain morphometric variables of significant clusters were explored. Results Primarily, most of the regions with statistically significant intergroup differences were located in the temporal lobe gyri. Importantly, the volume of bilateral superior temporal gyrus (STG) and the average cortical thickness of the right STG demonstrated significantly age-related intergroup differences. Further age-stratified analysis also revealed morphological alterations of STG among subgroups of preschool and school-aged children with or without HFA. Conclusion The findings demonstrated abnormal age-related volume and cortical thickness atrophy of the STG in HFA children, which reflect brain development trajectories of ASD may initiate to diverge from early overgrowth in childhood period. The anatomical localization of specific brain regions would help us better understand the neurobiology alterations of HFA patients and indicate the effect of age should be carefully delineated and examined in future studies about HFA.

ObjectiveWe present a semi-automated method for quantifying structural changes after epilepsy surgery that accounts for tissue deformation caused by resection. We demonstrate its utility by comparing the remote structural effects of two surgical approaches, the anterior temporal lobectomy (ATL) and the selective amygdalohippocampectomy (SAH).MethodsWe studied 37 temporal lobe epilepsy (TLE) patients who underwent resective surgery. Patients were treated with either an anterior temporal lobectomy (ATL, N=21) or a selective amygdalohippocampectomy (SAH, N=16). All patients received same-scanner MR imaging preoperatively and postoperatively (5+ months after surgery). To analyze structural changes in remote brain regions, we (1) implemented an automated method for segmenting resections with manual review, (2) applied cost function masking to the resection zone, and (3) estimated longitudinal cortical thickness changes using Advanced Normalization Tools (ANTs). We then compared post-operative changes in cortical thickness between the two surgical groups in brain regions outside the resected area.ResultsPatients treated with ATL exhibited significantly greater cortical thinning globally when compared to patients treated with SAH (p = 0.049). There were significant focal differences between the two treatment groups in the ipsilateral frontal lobe (superior medial and medial orbital regions) and insula (p > 0.001, α = 0.05 Bonferroni corrected). No significant effects were seen in the contralateral hemisphere.SignificanceWe present and share a semi-automated pipeline for quantifying remote longitudinal changes in cortical thickness after neurosurgery. The technique is applicable to a broad array of applications, including surgical planning and mapping neuropsychological function to brain structure. Using this tool, we demonstrate that patients treated with SAH for refractory temporal lobe epilepsy have less postoperative cortical thinning in remote brain regions than those treated with ATL. We share all algorithm code and results to accelerate collaboration and clinical translation of our work.KEY POINTS BOXDifferent epilepsy surgical approaches lead to distinct patterns of postoperative cortical atrophy in remote brain regionsPatients treated with SAH have less postoperative cortical thinning than patients treated with ATLThe insula and frontal lobe demonstrated the greatest focal differences in postoperative cortical thinning when comparing SAH and ATLPostoperative cortical thinning analyses may inform surgical planning and our understanding of cognitive sequelae

BACKGROUND Recent studies suggest gliomas location may be correlated with specific biological signatures. Our purpose was to focus on the possible correlation between MGMT metilation status and Ki67 positivity with patient age, glioma location and lateralization. METHODS We performed a retrospective evaluation to assess the correlation between MGMT metilation status and Ki67 index positivity with patient age, glioma location and lateralization. RESULTS The study included 174 supratentorial gliomas. Of these, 144 tumors were high grade gliomas (HGGs) and 30 tumors were low grade gliomas (LGGs). In HGG group we detected an association between tumor location and MGMT status. Those GBMs located in the frontal lobe were significantly associated with MGMT methylated status (MGMT+) and Ki67

OBJECTIVE The optimal treatment paradigm for large arteriovenous malformations (AVMs) is controversial. One approach is volume-staged stereotactic radiosurgery (VS-SRS). The authors previously reported efficacy of VS-SRS for large AVMs in a multiinstitutional cohort; here they focus on risk of symptomatic adverse radiation effects (AREs). METHODS This is a multicentered retrospective review of patients treated with a planned prospective volume staging approach to stereotactically treat the entire nidus of an AVM, with volume stages separated by intervals of 3–6 months. A total of 9 radiosurgical centers treated 257 patients with VS-SRS between 1991 and 2016. The authors evaluated permanent, transient, and total ARE events that were symptomatic. RESULTS Patients received 2–4 total volume stages. The median age was 33 years at the time of the first SRS volume stage, and the median follow-up was 5.7 years after VS-SRS. The median total AVM nidus volume was 23.25 cm3 (range 7.7–94.4 cm3), with a median margin dose per stage of 17 Gy (range 12–20 Gy). A total of 64 patients (25%) experienced an ARE, of which 19 were permanent. Rather than volume, maximal linear dimension in the Z (craniocaudal) dimension was associated with toxicity; a threshold length of 3.28 cm was associated with an ARE, with a 72.5% sensitivity and a 58.3% specificity. In addition, parietal lobe involvement for superficial lesions and temporal lobe involvement for deep lesions were associated with an ARE. CONCLUSIONS Size remains the dominant predictor of toxicity following SRS, but overall rates of AREs were lower than anticipated based on baseline features, suggesting that dose and size were relatively dissociated through volume staging. Further techniques need to be assessed to optimize outcomes.

OBJECTIVE Ischemic events within the territory of the choroidal artery are an important cause of morbidity after temporal lobe epilepsy (TLE) surgery. The aim of the present study was to evaluate the rate of these ischemic events, their clinical presentation, and impact on patients’ health-related quality of life (HRQoL) after TLE surgery. METHODS Four hundred twenty-two consecutive patients undergoing temporal resections for drug-resistant TLE were retrospectively analyzed. All patients underwent presurgical multidisciplinary assessment using a standard protocol comprising clinical, neuroradiological, neuropsychological, and EEG data. Postoperative complications with corresponding imaging, neurological deficits, and disease-specific HRQoL questionnaires were evaluated. RESULTS The overall complication rate was 7.8% (n = 33). Fourteen patients (3.3%) suffered from ischemic events causing 6 permanent motor deficits, 3 with permanent aphasias, and 6 visual field defects that exceeded quadrantanopia. In 8 patients with anterior choroidal artery infarction, accounting for 57% of all ischemic events, infarction volume correlated positively with the occurrence of new permanent neurological deficits (8666 vs 1692 mm3, p = 0.032). Despite the occurrence of ischemic events, HRQoL improved in 71% of patients. However, infarction volume showed a negative correlation trend with HRQoL (Pearson’s r = −0.390, p = 0.094). There was a trend toward increased risk for ischemic events in patients who underwent selective amygdalohippocampectomy compared to patients who underwent anterior temporal lobectomy or temporal lesionectomy (RR 0.96, 95% CI 0.93–0.99, p = 0.08). CONCLUSIONS Choroidal artery infarctions are rare but relevant complications after TLE surgery, presenting with variable clinical courses ranging from devastating neurological deterioration to complete recovery. Despite the occurrence of postoperative infarction, most patients report improvement of HRQoL after TLE surgery. This study showed that the type of surgery appears to modulate the risk for these ischemic events.

Background Although aspects of brain morphology have been associated with chronic posttraumatic stress disorder (PTSD), limited work has investigated multimodal patterns in brain morphology that are linked to acute posttraumatic stress severity. In the present study, we utilized multimodal magnetic resonance imaging to investigate if structural covariance networks (SCNs) assessed acutely following trauma were linked to acute posttraumatic stress severity. Methods Structural magnetic resonance imaging data were collected around 1 month after civilian trauma exposure in 78 participants. Multimodal magnetic resonance imaging data fusion was completed to identify combinations of SCNs, termed structural covariance profiles (SCPs), related to acute posttraumatic stress severity collected at 1 month. Analyses assessed the relationship between participant SCP loadings, acute posttraumatic stress severity, the change in posttraumatic stress severity from 1 to 12 months, and depressive symptoms. Results We identified an SCP that reflected greater gray matter properties of the anterior temporal lobe, fusiform face area, and visual cortex (i.e., the ventral visual stream) that varied curvilinearly with acute posttraumatic stress severity and the change in PTSD symptom severity from 1 to 12 months. The SCP was not associated with depressive symptoms. Conclusions We identified combinations of multimodal SCNs that are related to variability in PTSD symptoms in the early aftermath of trauma. The identified SCNs may reflect patterns of neuroanatomical organization that provide unique insight into acute posttraumatic stress. Furthermore, these multimodal SCNs may be potential candidates for neural markers of susceptibility to both acute posttraumatic stress and the future development of PTSD.

BackgroundDisrupted whole-brain resting-state functional connectivity (RSFC) of the posterior cingulate (PCC) has been highlighted to associate with cognitive and affective dysfunction in major depressive disorder (MDD). However, prior findings showed certain inconsistency about the RSFC of the PCC in MDD. This study aims to investigate the aberrant RSFC of the PCC in MDD using anisotropic effect-size version of seed-based d mapping (AES-SDM). MethodsWeb of Science and PubMed were searched for studies investigating PCC-based RSFC in MDD. A total of 17 studies, involving 804 patients and 724 healthy controls (HCs), fit our selection criteria. Additionally, to seek for the link between functional and structural differences, we did a meta-analysis on the studies in conjunction with Voxel-based morphology (VBM) analysis. ResultsThe PCC showed higher RSFC with the left middle temporal gyrus (MTG) and the right middle frontal gyrus (MFG), and lower RSFC with the left superior frontal gyrus (SFG) and the left precuneus in patients with MDD than HCs. Notably, the left MTG and the left MFG were the overlapped regions of aberrant VBM and RSFC results.ConclusionsOur results indicated that the aberrant RSFC between the PCC and brain regions sub-serving cognitive control and emotional regulation in patients with MDD. And such functional alterations may have structural basis. These findings may underlie the mechanisms of deficits in cognitive control and emotional regulation of MDD.

Objective: to study cognitive, psychoemotional state and brain neuroimaging in middle-aged patients with chronic forms of cerebrovascular diseases on the background of the metabolic syndrome; to explore the clinical efficacy, safety, effects on cognitive performance, anxiety of Vitaxon® national drug in patients with chronic forms of cerebrovascular diseases on the background of metabolic syndrome. Materials and methods. An open controlled study involved 60 patients aged 42 to 61 years (Me = 52 [Q1 = 54; Q3 = 60]) with metabolic syndrome. Patients of the main group (n = 30) received Vitaxon® in addition to the standard treatment. In the control group (n = 30), patients received only basic therapy. The criterion for inclusion in the study was the presence of anxiety and cognitive disorders in patients with І–ІІ degree dyscirculatory encephalopathy against the background of metabolic syndrome. There was performed clinical and laboratory examination and neuropsychological testing by scales: МoСА; Spielberger; Beck; Schulte tables. Using volumetric method, on MRI scanner Toshiba Vantage Titan 1.5 we have evaluated the state of the brain in 41 patients. A correlation analysis has been conducted between indicators of cortical volume and white matter of the frontal and temporal lobes and cognitive and anxiety disorders in patients with metabolic syndrome and without it. Results. After 24 days of treatment, there was an improvement of cognitive functions by MoCA scale in both groups (in the main group before and after the treatment: by 1.5 points; in the control one — by 0.5 points), in the group, in which patients received Vitaxon®, the results achieved probability (p < 0.05). Indicators of reactive anxiety by Spielberger scale improved in the intervention group (42.4 ± 3.4 points and 24.6 ± 2.8 points on day 24), in the control the figures did not differ significantly (41.2 ± 3.2 points and 39.1 ± 2.1 points). Analysis of the results of testing by Schulte tables showed a probable decrease in task performance after treatment in the group received Vitaxon® (p < 0.05). Indicators of depression by HADS scale improved after treatment in both groups, but the degree of statistical probability is not reached. The analysis of volumetric studies showed a deterioration of cognitive functions by MoCA scale while reducing the volume of the cortex in the frontal and temporal lobes. There has been determined the correlation between indicators of cortical volume of frontal and temporal lobes and the results of cognitive function evaluation by MoCA scale. The index of correlation (r) was 0.49 for temporal lobe and 0.43 — for frontal lobes. Modules of correlation coefficients were of medium strength. Conclusions. Patients with metabolic syndrome showed a reduction in the volume of gray matter in the frontal and temporal lobes, which correlated with cognitive deficit by MoCA scale. These data suggest in a greater degree a mixed cognitive impairment — vascular and degenerative. Volumetric research in combination with neuropsychological one allows to predict subsequent development of the disease on the stage of mild cognitive impairment. The presence of neurotropic positive effect on cognitive and anxiety symptoms and no significant side effects enables to recommend Vitaxon® for the treatment of chronic cerebrovascular diseases in patients with metabolic syndrome.

Impaired semantic knowledge is a characteristic feature of some forms of frontotemporal dementia (FTD), particularly the sporadic disorder semantic dementia. Less is known about semantic cognition in the genetic forms of FTD caused by mutations in the genes MAPT, C9orf72, and GRN. We developed a modified version of the Camel and Cactus Test (mCCT) to investigate the presence of semantic difficulties in a large genetic FTD cohort from the Genetic FTD Initiative (GENFI) study. Six-hundred-forty-four participants were tested with the mCCT including 67 MAPT mutation carriers (15 symptomatic, and 52 in the presymptomatic period), 165 GRN mutation carriers (33 symptomatic, 132 presymptomatic), and 164 C9orf72 mutation carriers (56 symptomatic, 108 presymptomatic) and 248 mutation-negative members of FTD families who acted as a control group. The presymptomatic mutation carriers were further split into those early and late in the presymptomatic period (more than vs. within 10 years of expected symptom onset). Groups were compared using a linear regression model, adjusting for age and education, with bootstrapping. Performance on the mCCT had a weak negative correlation with age (rho = −0.20) and a weak positive correlation with education (rho = 0.13), with an overall abnormal score (below the 5th percentile of the control population) being below 27 out of a total of 32. All three of the symptomatic mutation groups scored significantly lower than controls: MAPT mean 22.3 (standard deviation 8.0), GRN 24.4 (7.2), C9orf72 23.6 (6.5) and controls 30.2 (1.6). However, in the presymptomatic groups, only the late MAPT and late C9orf72 mutation groups scored lower than controls (28.8 (2.2) and 28.9 (2.5) respectively). Performance on the mCCT correlated strongly with temporal lobe volume in the symptomatic MAPT mutation group (rho > 0.80). In the C9orf72 group, mCCT score correlated with both bilateral temporal lobe volume (rho > 0.31) and bilateral frontal lobe volume (rho > 0.29), whilst in the GRN group mCCT score correlated only with left frontal lobe volume (rho = 0.48). This study provides evidence for presymptomatic impaired semantic knowledge in genetic FTD. The different neuroanatomical associations of the mCCT score may represent distinct cognitive processes causing deficits in different groups: loss of core semantic knowledge associated with temporal lobe atrophy (particularly in the MAPT group), and impaired executive control of semantic information associated with frontal lobe atrophy. Further studies will be helpful to address the longitudinal change in mCCT performance and the exact time at which presymptomatic impairment occurs.

Background: Default mode network (DMN) is recognized to be involved in generation and propagation of epileptic activities in various epilepsies. Converging evidence has suggested disturbed functional connectivity (FC) in epilepsies, which was inferred to be related to underlying pathological mechanisms. However, abnormal changes of FC in DMN revealed by different studies are controversial, which obscures the role of DMN in distinct epilepsies. Objective: The present work aims to investigate the voxel-wise FC in DMN across epilepsies. Methods: A systematic review was conducted on 22 published articles before October 2020 indexed in PubMed and Web of Science. A meta-analysis with a random-effect model was performed using the effect-size signed differential mapping approach. Subgroup analyses were performed in three groups: idiopathic generalized epilepsy (IGE), mixed temporal lobe epilepsy (TLE), and mixed focal epilepsy (FE) with different foci. Results: The meta-analysis suggested common decreased FC in mesial prefrontal cortices across different epilepsies. Additional decreased FC in posterior DMN was observed in IGE. The TLE showed decreased FC in temporal lobe regions and increased FC in dorsal posterior cingulate cortex. Interestingly, an opposite finding in ventral and dorsal middle frontal gyrus was observed in TLE. The FE demonstrated increased FC in cuneus. Conclusion: The current findings revealed both common and specific alterations of FC in DMN across different epilepsies, highlighting the contribution of these dysfunctions to epileptic activities and cognitive behaviors in patients. Furthermore, the current study provided powerful evidence to support DMN as a potential candidate for effective intervention in epilepsy.

OBJECTIVE We sought to determine whether extracranial carotid atherosclerotic disease (ECAD) is associated with increased key neurodegenerative pathology such as neurofibrillary tangle (NFT), beta-amyloid plaque, or cerebral amyloid angiopathy (CAA) accumulation, findings associated with Alzheimer's disease (AD) and other dementias. METHODS Our prospective, longitudinal, clinicopathologic study, the AZSAND (Arizona study of aging and neurodegenerative disorders) and Brain and Body Donation Program, recorded the presence or absence of clinically diagnosed ECAD and performed semiquantitative density estimates of NFT, beta-amyloid plaque, and CAA at death. After adjusting for potential confounding factors determined by logistic regression analysis, histopathology density scores were evaluated in individuals with ECAD (n = 66) and those without ECAD (n = 125). RESULTS We found that the presence of ECAD was associated with a 21% greater NFT burden at death compared with no ECAD (P = .02). Anatomically, an increased NFT burden was seen throughout the brain regions evaluated but was significant in the temporal lobe (P < .05) and entorhinal cortex (P = .02). In addition, we found that subjects who had undergone carotid endarterectomy (CEA), the surgical treatment of ECAD (n = 32), had decreased NFT densities compared with those with ECAD who had not undergone CEA (n = 66; P = .04). In contrast to NFT, ECAD was not associated with beta-amyloid plaques or CAA density. CONCLUSIONS These findings indicate that ECAD is associated with the NFT burden in the temporal lobe and entorhinal cortex, which has clinical significance for AD and non-AD dementias and cognitive dysfunction. Further understanding of whether ECAD increases the risk of neurodegenerative brain changes is highly relevant because ECAD is a treatable disease that has not, otherwise, been evaluated for nor specifically treated as a dementia risk factor.

Contrary to traditional theories of declarative memory, it has recently been shown that novel, arbitrary associations can be rapidly and directly integrated into cortical memory networks by means of a learning procedure called fast mapping (FM), possibly bypassing time-consuming hippocampal-neocortical consolidation processes. In the typical FM paradigm, a picture of a previously unknown item is presented next to a picture of a previously known item and participants answer a question referring to an unfamiliar label. It is assumed that they thereby incidentally create associations between the unknown item and the label. However, contradictory findings have been reported and factors moderating rapid cortical integration through FM yet need to be identified. In the context of previous behavioral results showing rapid semantic integration through FM especially if the unknown and the known item shared many features, we propose that due to its computational mechanisms during the processing of complex and particularly highly similar objects, the perirhinal cortex might be especially qualified to support the rapid incorporation of these associations into cortical memory networks within the FM paradigm. We therefore expected that a high degree of feature overlap between the unknown and the known item would trigger strong engagement of the perirhinal cortex at encoding, which in turn might enhance rapid cortical integration of the novel picture-label associations. Within an fMRI experiment, we observed stronger activation for subsequent hits than misses during encoding in the perirhinal cortex and an associated anterior temporal network if the items shared many features than if they shared few features, indicating that the perirhinal cortex indeed contributes to the acquisition of novel associations by means of FM if feature overlap is high.

Background The relatively isolated atrophy of the temporal lobes leads to a clinical radiological pattern, referred to as the temporal variant of frontotemporal dementia. While semantic dementia and behavioral variant frontotemporal dementia are classically related to this syndrome, the logopenic variant of primary progressive aphasia has been less commonly reported. This case report aims to give a pictorial description of a case in which a patient with asymmetric temporal lobe atrophy presented with the logopenic variant of primary progressive aphasia and complex rituals of cleanliness. Case presentation We report on the case of a 68-year-old, right-handed White woman with complex rituals and progressive speech impairment. The obsessive–compulsive rituals represented an exacerbation of lifelong preoccupations with cleanliness and orderliness that were praised by her relatives. Neuropsychological assessment revealed a striking impairment of language and memory, with relative sparing of tool-use praxis and visuospatial skills. Magnetic resonance imaging and 18fluorodeoxyglucose-positron emission tomography scans showed bilateral asymmetrical temporal lobe atrophy and hypometabolism. A year later, she was still able to entertain conversation for a short while, but her vocabulary and fluency had further declined. Praxis and visuospatial skills remained intact. She did not experience pathological elation, delusions, or hallucinations. The disease followed a relentless progression into a partial Klüver–Bucy syndrome, abulia, and terminal dementia. She died from acute myocardial infarction 8 years after the onset of aphasia. The symptoms and their temporal course supported a diagnosis of logopenic variant of primary progressive aphasia due to asymmetric temporal variant frontotemporal lobar degeneration. Conclusions This report gives a pictorial description of a temporal variant of frontotemporal dementia in a patient who presented with worsening of a lifelong obsessive–compulsive disorder and logopenic variant of primary progressive aphasia.

OBJECTIVE The aim of this study was to investigate the epidemiological characteristics, associated risk factors, and prognostic value of glioma-related epilepsy in patients with diffuse high-grade gliomas (DHGGs) that were diagnosed after the 2016 updated WHO classification was released. METHODS Data from 449 patients with DHGGs were retrospectively collected. Definitive diagnosis was reaffirmed according to the 2016 WHO classification. Seizure outcome was assessed using the Engel classification at 12 months after surgery. Univariate and multivariate analyses were performed to identify risk factors associated with preoperative and postoperative glioma-related epilepsy. Lastly, the prognostic value of glioma-related epilepsy was evaluated by Kaplan-Meier and Cox analysis. RESULTS The incidence of glioma-related epilepsy decreased gradually as the malignancy of the tumor increased. Age < 45 years (OR 2.601, p < 0.001), normal neurological function (OR 3.024, p < 0.001), and lower WHO grade (OR 2.028, p = 0.010) were independently associated with preoperative glioma-related epilepsy, while preoperative glioma-related epilepsy (OR 7.554, p < 0.001), temporal lobe involvement (OR 1.954, p = 0.033), non–gross-total resection (OR 2.286, p = 0.012), and lower WHO grade (OR 2.130, p = 0.021) were identified as independent predictors of poor seizure outcome. Furthermore, postoperative glioma-related epilepsy, rather than preoperative glioma-related epilepsy, was demonstrated as an independent prognostic factor for overall survival (OR 0.610, p = 0.010). CONCLUSIONS The updated WHO classification seems conducive to reveal the distribution of glioma-related epilepsy in DHGG patients. For DHGG patients with high-risk predictors of poor seizure control, timely antiepileptic interventions could be beneficial. Moreover, glioma-related epilepsy (especially postoperative glioma-related epilepsy) is associated with favorable overall survival.

Introduction Temporal engagement may persist after etiologic surgical treatment of acute subdural hematoma (ASH) without clinical improvement despite normalized intracranial pressure (ICP). The aim of this study was to assess the feasibility of secondary direct temporal lobe disengagement (DTLD) after surgery for supratentorial ASH and to evaluate clinical outcome. Materials and methods This was a retrospective analysis of 4 patients undergoing secondary DTLD. Patient data were recorded at admission, pre- and postoperatively and at 6 months’ follow-up (FU): age, gender, Rotterdam score, Glasgow Coma Scale (GCS), neurological deficits, oculomotor nerve palsy (ONP), ICP, midline shift, complications and Extended Glasgow Outcome Scale (GOS-E). Results At postoperative evaluation 48 h after DTLD, we observed a significant improvement in GCS score (initial 6 ± 3, preoperative 7 ± 3, postoperative 14 ± 1; P = 0.02), midline shift (initial 16 ± 3 mm, preoperative 13 ± 5 mm, postoperative 9 ± 2 mm; P = 0.049) and ONP (P = 0.01). In all cases, early postoperative imaging documented visualization of a patent ipsilateral peri-mesencephalic cistern. At 6-month FU, GOS-E showed 75% good recovery and 25% disability. Complete ONP recovery was observed in 75% of patients (P = 0.01). Neurological deficits were present at FU in 25% of patients. No surgery-related complications or mortality were recorded. Conclusions In traumatic brain injury, secondary DTLD may allow simple, effective and safe management of trans-tentorial uncal herniation, avoiding more challenging procedures. Clinical results are promising, as this technique seems to favorably influence neurological outcome in this selected subgroup of patients with persistent clinical and radiological signs of temporal engagement after etiological treatment with normal ICP values.

Background Laser interstitial thermal therapy (LITT) is a minimally invasive alternative to anterior temporal lobectomy (ATL) for treatment of temporal lobe epilepsy. It has gained popularity as familiarity with technique increases and outcomes are better characterized. There has been no direct cost comparison between the 2 techniques in literature to date. The current study directly compares hospital costs associated with LITT with those of ATL patients and analyzes the factors potentially responsible for those costs. Methods Patients who underwent ATL (27) and LITT (15) were retrospectively reviewed for total hospital costs along with demographic, surgical, and postoperative factors potentially affecting cost. T-tests were used to compare costs and independent linear regressions, and hierarchical regressions were used to examine predictors of cost for each procedure. Results Mean hospital costs of admission for single-trajectory LITT ($104,929.88) were significantly less than for ATL ($134,980.04) (P = 0.001). In addition, length of stay, anesthesia costs, operative room costs, and postoperative hospitalization costs were all significantly lower in LITT. Conclusions Given the minimally invasive nature of LITT, it is associated with shorter length of stay and lower hospital costs than ATL in the first head-to-head comparison of procedural costs in literature to date. Long-term efficacy as it relates to these costs associated with LITT and ATL should be further investigated to better characterize the utility of LITT in temporal lobe epilepsy patients.

Objective: We aimed to determine the association between a polymorphism in the promoter region of the IL-1beta gene resulting in enhanced gene transcription and the clinical phenotype of temporal lobe epilepsy with hippocampal sclerosis (TLE+HS). Materials and Methods: The frequency of a single nucleotide polymorphism (SNP) that results in a C>T transition of 511 base pairs that are five prime to the transcription start site of the IL-1beta gene in a group of 21 patients with TLE+HS, 21 patients with temporal lobe epilepsy without hippocampal sclerosis (TLE-HS), and 23 healthy volunteers. Results: The frequency of the -511T allele was 11/21 in the TLE-HS group, 13/21 in the TLE+HS group, and 12/23 in the control group. Chi-square analysis of genotype and allele distribution showed no significant difference between the patients in TLE+HS, TLE-HS, and control group Conclusion: There was no association between the -511/C>T SNP variation and TLE+HS.

Temporal lobe epilepsy (TLE) often occurs in childhood and is the most common type of epilepsy. Studies have confirmed that long non-coding RNAs (lncRNAs) can affect the progression of neurological diseases. This study explored the expression level of lncRNA TUG1 in TLE children and its clinical significance and investigated its role in hippocampal neurons. 86 healthy individuals and 88 TLE children were recruited. The expressions of lncRNA TUG1 and miR-199a-3p in serum were detected by qRT-PCR. Hippocampal neurons were treated with non-Mg2+ to establish TLE cell model. MTT assay and flow cytometry assay was used to detect the effect of lncRNA TUG1 on the proliferation and apoptosis of hippocampal neurons. A dual-luciferase reporter assay was done to confirm the target relationship. The expression of lncRNA TUG1 was increased in TLE children compared with the control group. The diagnostic potential was reflected by the receiver operator characteristic (ROC) curve, with the AUC of 0.915 at the cutoff value of 1.256. Elevated levels of TUG1 were detected in TLE cell models, and TUG1 knockout could enhance cell activity and inhibit cell apoptosis. MiR-199a-3p was the target of TUG1. Clinically, the serum miR-199a-3p levels showed a negative association with TUG1. LncRNA TUG1 may be a biomarker of TLE diagnosis in children, and can regulate hippocampal neuron cell activity and apoptosis via sponging miR-199a-3p.

Drug-resistant temporal lobe epilepsy (TLE) is a potential candidate for surgery; however, nearly one-third subjects had a poor surgical prognosis. We studied the underlying neuromechanism related to the surgical prognosis using graph theory based on metabolic brain network. Sixty-four unilateral TLE subjects with preoperative 18F-fluorodeoxyglucose (FDG) PET scanning were retrospectively enrolled and divided into Ia (Engel class Ia, n = 32) and non-Ia (Engel class Ib-IV, n = 32) groups according to more than 3-year follow-up after unilateral anterior temporal lobectomy (ATL). The metabolic brain network was constructed and the changed metabolic connectivity of Ia and non-Ia was detected compared with 15 matched healthy controls (HCs). Further, the network properties, including small-worldness and global efficiency, were calculated and hub nodes were also identified for the 3 groups respectively. Non-Ia group exhibited increased connectivity between contralateral fusiform gyrus and contralateral lingual gyrus; while Ia showed decreased connectivity mainly among bilateral frontal, temporal and parietal cortex. Graph theoretical analysis revealed that non-Ia group showed increased small-worldness (35% L p (P = 0.05) compared to Ia group. Ia group showed reduced C p (55%

This article analyzes data from scientific publications (mainly reviews) concerning the link between human neurocysticercosis and epilepsy. Along with data from our own studies on experimental hippocampal sclerosis induced by a Taenia crassiceps metacestode factor in mice, it explores the connection between mechanisms that likely favor the development of epilepsy in cases of human neurocysticercosis. The data from both sources suggest the idea that the T. solium metacestode factor causes hippocampal sclerosis and later epilepsy in humans with neurocysticercosis.

Objective To determine the predictive power for seizure-freedom of 19-channels EEG, measured both before and after three months the initiation of the use of Levetiracetam (LEV), in a cohort of people after a new diagnosis of temporal-lobe epilepsy (TLE) using a machine-learning approach. Methods Twenty-three individuals with TLE were examined. We dichotomized clinical outcome into seizure-free (SF) and non-seizure-free (NSF) after two years of LEV. EEG effective power in different frequency bands was compared using baseline EEG (T0) and the EEG after three months of LEV therapy (T1) between SF and NSF patients. Partial Least Square (PLS) analysis was used to test and validate the prediction of the model for clinical outcome. Results A total of 152 features were extracted from the EEG recordings. When considering only the features calculated at T1, a predictive power for seizure-freedom (AUC = 0.750) was obtained. When employing both T0 and T1 features, an AUC = 0.800 was obtained. Conclusions This study provides a proof-of-concept pipeline for predicting the clinical response to anti-seizure medications in people with epilepsy. Significance Future studies may benefit from the pipeline proposed in this study in order to develop a model that can match each patient to the most effective anti-seizure medication.

Objective To highlight specific characteristics of seizure semiology and EEG features associated with different subtypes of autoimmune encephalitis (AE). Methods We systematically reviewed the seizure semiology and all the EEG recordings from patients with AE managed in a tertiary referral centre for epilepsy and a neuro-intensive care unit. Each characteristic across the different subtypes of AE was compared by post hoc analysis. Results We identified 66 patients with anti-neuronal antibody-mediated AE or Rasmussen's encephalitis (RE) experiencing seizures, which were the most frequent symptom at onset. Anti-NMDAR and anti-LGI1 AE accounted for the majority of patients; 41% and 24%, respectively. We isolated specific semiological features, such as early tonic-clonic seizures (TCS) in anti-NMDAR AE, early mesial temporal lobe seizures with emotional symptoms in anti-GAD AE, somatosensory seizures in RE, and a lower frequency of TCS in anti-LGI1 AE. EEG analysis also provided additional insights into distinguishing the subtypes based on: (1) generalized rhythmic delta activity, which was more sensitive than extreme delta brush in identifying anti-NMDAR AE among all subtypes; and (2) temporal interictal epileptiform activity and temporal seizures on EEG in anti-GAD AE. We identified a new EEG pattern consisting of temporal low-voltage and periodic spikes associated with ipsilateral hippocampal abnormalities on MRI, which could be a sign of inflammatory mesial temporal involvement. Significance Specific clinical and EEG features can be useful in guiding the diagnosis of a subtype of AE with acute symptomatic seizures, particularly before the results of anti-neuronal antibody testing are available.

Background: Evidence suggests that cortical anatomy may be aytpical in autism spectrum disorder. The wingless-type MMTV integration site family, member 2 (WNT2), a candidate gene for autism spectrum disorder, may regulate cortical development. However, it is unclear whether WNT2 variants are associated with altered cortical thickness in autism spectrum disorder. Methods: In a sample of 118 people with autism spectrum disorder and 122 typically developing controls, we investigated cortical thickness using FreeSurfer software. We then examined the main effects of the WNT2 variants and the interactions of group × SNP and age × SNP for each hemisphere and brain region that was altered in people with autism spectrum disorder. Results: Compared to neurotypical controls, people with autism spectrum disorder showed reduced mean cortical thickness in both hemispheres and 9 cortical regions after false discovery rate correction, including the right cingulate gyrus, the orbital gyrus, the insula, the inferior frontal gyrus (orbital part and triangular part), the lateral occipitotemporal gyrus, the posterior transverse collateral sulcus, the lateral sulcus and the superior temporal sulcus. In the full sample, 2 SNPs of WNT2 (rs6950765 and rs2896218) showed age × SNP interactions for the mean cortical thickness of both hemispheres, the middle-posterior cingulate cortex and the superior temporal cortex. Limitations: We examined the genetic effect for each hemisphere and the 9 regions that were altered in autism spectrum disorder. The age effect we found in this cross-sectional study needs to be examined in longitudinal studies. Conclusion: Based on neuroimaging and genetic data, our findings suggest that WNT2 variants might be associated with altered cortical thickness in autism spectrum disorder. Whether and how these WNT2 variants might involve cortical thinning requires further investigation. Trial registration: ClinicalTrials.gov no. NCT01582256. Protocol registration: National Institutes of Health no. NCT00494754.

Background : Neuroimaging studies have revealed abnormal cortical folding pattern and disruptive functional connectivity in major depressive disorder (MDD). Combining structure and function in the same population may further our understanding of the neuropathological mechanisms of MDD. Method : Sixty-two patients with MDD and 61 healthy controls (HCs) underwent structural and resting-state functional magnetic resonance imaging (MRI). Group differences in the cortical folding (measured by local gyrification index (LGI)) were analyzed in FreeSurfer. Taking the brain regions with significant group differences in LGI as seed regions, the resting-state functional connectivity analysis was further conducted to explore the corresponding functional connectivity alterations. Results : Comparing with HCs, patients with MDD showed significantly decreased LGI in the right fusiform gyrus (cohen's d = 0.70). In the seed-based functional connectivity analysis, we found that compared with HCs, patients with MDD showed decreased functional connections between the right fusiform gyrus with sensorimotor areas (precentral and postcentral gyrus) (cohen's d = 1.32) and right superior temporal gyrus (cohen's d = 0.94). Limitations : Main limitations are the relatively small sample size and the cross-sectional study design. Conclusion : Decreased LGI in the right fusiform gyrus, as well as decreased functional connectivity between the right fusiform gyrus and the sensorimotor area and right superior temporal gyrus, appears to play a role in the pathophysiology of MDD.

Cognitive control and working memory (WM) processes are essential for goal-directed behaviour. Cognitive control and WM are probably based on overlapping neurophysiological mechanisms. For example, theta-band activity (TBA) plays an important role in both functions. For cognitive control processes, it is known that different aspects of information about stimulus content, motor processes and stimulus-response relationships are encoded simultaneously in the TBA. All this information is probably processed during WM gating processes and must be controlled during them. However, direct data for this are lacking. This question is investigated in this study by combining methods of EEG temporal signal decomposition, time-frequency decomposition and beamforming. We show that portions of stimulus-related information, motor response-related information and information related to the interaction between the stimulus and motor responses in the TBA are influenced in parallel and to a similar extent by WM gate opening and gate closing processes. Nevertheless, it is stimulus-related information in the theta signal in particular that modulates behavioural performance in WM-gating. The data suggest that the identified processes are implemented in specific neuroanatomical structures. In particular, the medial frontal cortex, temporal cortical regions and insular cortex are involved in these dynamics. The study shows that principles of information coding relevant to cognitive control processes are also crucial for understanding WM gating.

In order to navigate in our complex social world successfully, it is crucial to maintain and practice cognitive skills that are dedicated to adaptive social functioning. Emerging evidence suggests that besides deficits in declarative memory, executive functions, and language, impairments in social cognition (SC, e.g., emotion recognition, theory of mind) are also present in temporal lobe epilepsy (TLE). The organic and psycho-social consequences of epilepsy surgery might have additional implications regarding this deficit. Here we qualitatively synthesize longitudinal and cross-sectional findings on SC after TLE surgery. A literature search using PubMed and Scopus identified 275 potential articles. Studies were eligible if they (1) included patients with a diagnosis of TLE, (2) included a healthy comparison group, (3) reported original research, (4) were published in peer-reviewed journals and in English language, (5) reported the intervention of epilepsy surgery. Articles that (1) were case studies, (2) did not focus on SC abilities, (3) used interviews or self-report questionnaires to examine SC functions were excluded. A total of 16 original studies assessing emotion recognition (ER) and/or theory of mind (ToM) matched our criteria. The literature suggests that neither ER nor ToM abilities change after surgery: post-surgery patients show similar impairment patterns to pre-surgery patients. Nevertheless, individual improvement or decline could be masked by group comparisons and results should be considered in light of methodological heterogeneity among studies.

Introduction: compression of the labyrinthine segment of the facial nerve by edema has been considered as an important pathology in the majority of the cases of idiopathic facial nerve paralysis. Hence, it is suggested that total decompression of the facial nerve should also include the labyrinthine segment by a middle fossa approach. However, the middle fossa approach requires craniotomy and temporal lobe retraction, which increases the morbidity. The labyrinthine segment of the facial nerve can also be reached through mastoidectomy. However, many ear surgeons are not familiar with this approach due to the lack of anatomical data on this surgical area. Objective: to study the anatomical limitations of decompression of the labyrinthine segment via transmastoid approach. Methods: complete mastoidectomy was performed in six adult cadavers heads. Dissection was extended in the zygomatic root and posterior bony wall of the external auditory canal to visualize the incudomallear joint completely. The bone between tympanic segment, lateral and superior semicircular canal's ampullas and middle fossa dural plate was removed. Fine dissection was carried out over tympanic segment of the facial nerve in an anterosuperomedial direction the labyrinthine segment was reached. Results: all the mastoids were well pneumatized. Distances between the labyrinthine segment and middle fossa dura, and between the labyrinthine segment and superior semicircular canal, were 2.5 and 4.5 mm on average, respectively. In addition, distances between the middle fossa dura and dome of the lateral semicircular canal, and between the middle fossa dura and tympanic segment were 4.6 mm and 4.3 mm on average, respectively. Conclusion: it is possible to expose the labyrinthine segment of the facial nerve through mastoidectomy by dissecting the bone in the area between the tympanic segment of the facial nerve, middle fossa dural plate and ampullary ends of the lateral and superior semicircular canals., NA