4,188 results match your criteria: "Neuroimaging in Epilepsy Surgery"

Mapping the basal temporal language network: a SEEG functional connectivity study.

Brain Lang

November 2024

Lorraine University, CHRU Nancy, Neurology Department, Nancy, France; Lorraine University, CNRS, IMoPA, F-54000, Nancy, France.

Article Synopsis
  • - The Basal Temporal Language Area (BTLA) is identified in epilepsy surgery when stimulation in the ventral temporal cortex (VTC) causes naming difficulties like anomia or paraphasia, highlighting the need for a better understanding of this language area.
  • - A study using cortico-cortical evoked potentials in nine epilepsy patients found strong connectivity in eloquent regions of the left VTC, indicating a structured basal temporal language network (BTLN) that interacts closely with brain areas like the amygdala and hippocampus.
  • - The fusiform gyrus serves as a multimodal integrator within this network, enhancing our comprehension of how the ventral temporal region processes language.
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Article Synopsis
  • Microsurgical resection of epilepsy-related lesions carries risks of motor impairment, prompting the exploration of less invasive options like MRI-guided laser interstitial thermal therapy (MRgLITT) which has shown improved neurological outcomes.
  • A case study of a 17-year-old athlete highlighted the use of advanced tractography techniques to map the corticospinal tract (CST), aiding in presurgical planning and guiding the MRgLITT procedure.
  • The integration of CST tractography proved to be effective in enhancing the MRgLITT process, allowing for successful tumor ablation while preserving motor function, although challenges in tractography accuracy and thermal output predictability remain to be addressed.
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Objective: Interictal biomarkers are critical for identifying the epileptogenic focus. However, spikes and ripples lack specificity while fast ripples lack sensitivity. These biomarkers propagate from more epileptogenic onset to areas of spread.

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Article Synopsis
  • Subcortical brain structures play a crucial role in various disorders, and a study analyzed the genetic basis of brain volumes in nearly 75,000 individuals of European ancestry, revealing 254 loci linked to these volumes.
  • The research identified significant gene expression in neural cells, relating to brain aging and signaling, and found that polygenic scores could predict brain volumes across different ancestries.
  • The study highlights genetic connections between brain volumes and conditions like Parkinson's disease and ADHD, suggesting specific gene expression patterns could be involved in neuropsychiatric disorders.
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Variability of cortico-cortical evoked potentials in the epileptogenic zone is related to seizure occurrence.

Ann Clin Transl Neurol

October 2024

Department of Neurology, Université libre de Bruxelles (ULB), Hôpital Universitaire de Bruxelles (HUB), Hôpital Erasme, Bruxelles, Belgium.

Article Synopsis
  • This study investigates the variability of cortico-cortical evoked potentials (CCEPs) during single-pulse electrical stimulations to understand their relationship with seizure activity in patients with epilepsy.
  • Researchers analyzed data from 20 patients with a focus on how CCEP measurements changed in relation to the location of the epileptogenic zone (EZ) and the occurrence of interictal discharges.
  • Findings indicate that increased seizure frequency correlates with decreased variability in CCEP measurements, suggesting that the epileptogenic network becomes more interconnected with frequent seizures, emphasizing the need for timely epilepsy surgery.
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Objective: The purpose of this study was to evaluate the performance and generalizability of an automated, interpretable surface-based MRI classifier for the detection of focal cortical dysplasia.

Methods: This was a retrospective cohort incorporating MRIs from the epilepsy surgery (FCD and MRI-negative) and neuroimaging (healthy controls) databases at Children's National Hospital (CNH), and a publicly-available FCD Type II dataset from Bonn, Germany. Clinical characteristics and outcomes were abstracted from patient records and/or existing databases.

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Article Synopsis
  • Pleomorphic xanthoastrocytoma (PXA) is a rare brain tumor first reported in 1979, mostly found in the temporoparietal lobe, and it usually has a good outcome.
  • The most common symptoms are seizures, but about 50-78% of patients may also have psychiatric issues like anxiety, depression, or even schizophrenia-like symptoms.
  • A recent case involved a 26-year-old man who had seizures and schizophrenia-like psychosis for 5 years; after surgery, his condition improved, showing how important surgery can be for this type of tumor.
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Article Synopsis
  • The study focused on patients with temporal lobe epilepsy and hippocampal sclerosis, comparing those with gray-white matter abnormalities (GMB+) to those without (GMB-).
  • Researchers analyzed 105 patients and 61 healthy controls using MRI and light microscopy, examining brain structure and connectivity related to their epilepsy.
  • Findings indicated that GMB+ patients showed more extensive white matter damage and a higher rate of certain types of hippocampal sclerosis, which may influence surgical treatment decisions.
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Background And Objectives: Complete resection of epileptogenic zone is the single most important determinant of favorable seizure outcomes in resective surgery. However, identifying and resecting this zone is challenging in patients harboring diffuse; MRI-occult malformations of cortical development, such as focal cortical dysplasia; or acquired pathology, such as Rasmussen encephalitis. Intraoperative adjuncts that can aid in identifying the lesion and/or epileptogenic zone can optimize the extent of resection and seizure outcome.

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During discourse comprehension, every new word adds to an evolving representation of meaning that accumulates over consecutive sentences and constrains the next words. To minimize repetition and utterance length, languages use pronouns, like the word "she," to refer to nouns and phrases that were previously introduced. It has been suggested that language comprehension requires that pronouns activate the same neuronal representations as the nouns themselves.

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Dynamic functional connectivity in verbal cognitive control and word reading.

Neuroimage

October 2024

Department of Pediatrics, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI 48201, United States; Department of Neurology, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI 48201, United States; Department of Pediatrics, Central Michigan University, Mt. Pleasant, MI 48858, United States; Translational Neuroscience Program, Wayne State University, Detroit, MI 48201, United States. Electronic address:

Cognitive control processes enable the suppression of automatic behaviors and the initiation of appropriate responses. The Stroop color naming task serves as a benchmark paradigm for understanding the neurobiological model of verbal cognitive control. Previous research indicates a predominant engagement of the prefrontal and premotor cortex during the Stroop task compared to reading.

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Article Synopsis
  • This study explored the interactions between temporal and frontal brain regions in patients with temporal lobe epilepsy (TLE), focusing on different disease durations.
  • It analyzed magnetoencephalography data from 36 seizure-free TLE patients and 21 healthy controls, dividing patients into long-term (more than 10 years) and short-term (10 years or less) based on disease duration.
  • The results highlighted increased coupling between brain wave phases and amplitudes in TLE patients, revealing positive correlations between this coupling and longer disease duration, as well as changes in connectivity directions between frontal and temporal regions.
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Resting state connectivity biomarkers of seizure freedom after epilepsy surgery.

Neuroimage Clin

November 2024

Epilepsy Center, Medical Center, University of Freiburg, Breisacher Str. 64, 79106 Freiburg im Breisgau, Germany.

Alterations in brain networks may cause the lowering of the seizure threshold and hypersynchronization that underlie the recurrence of unprovoked seizures in epilepsy. The aim of this work is to estimate functional network characteristics, which may help predicting outcome of epilepsy surgery. Twenty patients were studied (11 females, 9 males, mean age 33 years) with scalp-recorded HD-EEG in resting state (eyes closed, no interictal discharges) before intracranial evaluation, which allowed the precise determination of the epileptogenic zone.

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Discordant Wada and fMRI language lateralization: a case report.

J Int Med Res

September 2024

Key Laboratory of Brain Functional Genomics (MOE and Shanghai), Institute of Cognitive Neuroscience, School of Psychology and Cognitive Science, East China Normal University, Shanghai, China.

Functional MRI (fMRI) is gaining importance in the preoperative assessment of language for presurgical planning. However, inconsistencies with the Wada test might arise. This current case report describes a very rare case of an epileptic patient who exhibited bilateral distribution (right > left) in the inferior frontal gyrus (laterality index [LI] = -0.

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EEG Findings in a Patient with Holmes Tremor after AVM Surgery: A Case Report and Literature Review.

Clin EEG Neurosci

September 2024

Department of Neurosurgery, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, People's Republic of China.

Holmes tremor (HT) is a rare motor disorder characterized by high-amplitude and low-frequency resting, intentional, and postural tremors. HT typically arises from disruptions in neural pathways, including the dopaminergic system. Its causes include cerebrovascular incidents, neoplasms, demyelination, and infections.

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Unexpected seizures significantly decrease the quality of life in epileptic patients. Seizure attacks are caused by hyperexcitability and anatomical lesions of special regions of the brain, and cognitive impairments and memory deficits are their most common concomitant effects. In addition to seizure reduction treatments, medical rehabilitation involving brain-computer interfaces and neurofeedback can improve cognition and quality of life in patients with focal epilepsy in most cases, in particular when resective epilepsy surgery has been considered treatment in drug-resistant epilepsy.

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Spatiotemporal Neural Network for Sublexical Information Processing: An Intracranial SEEG Study.

J Neurosci

November 2024

National Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China

Words offer a unique opportunity to separate the processing mechanisms of object subcomponents from those of the whole object, because the phonological or semantic information provided by the word subcomponents (i.e., sublexical information) can conflict with that provided by the whole word (i.

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Region-specific MRI predictors of surgical outcome in temporal lobe epilepsy.

Neuroimage Clin

September 2024

Neuroimaging of Epilepsy Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada. Electronic address:

Objective: In drug-resistant temporal lobe epilepsy (TLE), it is not well-established in how far surgery should target morphological anomalies to achieve seizure freedom. Here, we assessed interactions between structural brain compromise and surgery to identify region-specific predictors of seizure outcome.

Methods: We obtained pre- and post-operative 3D T1-weighted MRI in 55 TLE patients who underwent selective amygdalo-hippocampectomy (SAH) or anterior temporal lobectomy (ATL) and 40 age and sex-matched healthy subjects.

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Article Synopsis
  • The study aimed to assess cognitive changes after surgery that involved removing areas of the brain with significant high-gamma power modulations (HGM) during a visual naming task, even though these areas were not identified as language-critical during standard electrical stimulation mapping.
  • Researchers analyzed the cognitive outcomes of 37 drug-resistant epilepsy patients one year after surgery, highlighting the effects of lesioning HGM language sites on various neuropsychological assessments, specifically measuring reliable change indices (RCIs).
  • Results showed that lesioning even one HGM language site was associated with significant declines in scores for vocabulary, working memory, and verbal learning, indicating that these areas play an important role in cognitive function, despite being categorized as non-language sites through electrical mapping.
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Introduction: Operculo-insular epilepsy (OIE) is a rare condition amenable to surgery in well-selected cases. Despite the high rate of neurological complications associated with OIE surgery, most postoperative deficits recover fully and rapidly. We provide insights into this peculiar pattern of functional recovery by investigating the longitudinal reorganization of structural networks after surgery for OIE in 10 patients.

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Transcranial magnetic stimulation and magnetoencephalography are feasible alternatives to invasive methods in optimizing responsive neurostimulation device placement.

Epilepsy Res

October 2024

Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, USA; Department of Pediatrics, Division of Pediatric Neurology, University of Tennessee Health Science Center, Memphis, TN, USA; Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA. Electronic address:

Article Synopsis
  • - Responsive neurostimulation (RNS) is an option for treating refractory epilepsy when surgery isn't viable, and this study explored using non-invasive methods like transcranial magnetic stimulation (TMS) and magnetoencephalography (MEG) for presurgical evaluations instead of invasive techniques.
  • - The study reviewed nine patients who underwent RNS placement, finding that MEG successfully characterized the irritative zone in eight patients, while TMS successfully mapped eloquent cortex areas in eight out of nine patients.
  • - The results indicated that patients evaluated with non-invasive methods saw an average seizure reduction of 77%, similar to the 75% experienced by those evaluated invasively, suggesting that TMS and MEG are promising alternatives for optimizing R
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Advances in MRI-based diagnosis of temporal lobe epilepsy: Correlating hippocampal subfield volumes with histopathology.

J Neuroimaging

November 2024

Centre for Neuroscience Studies, Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada.

Article Synopsis
  • Epilepsy affects about 0.5%-1% of people worldwide, with 30% of those patients not responding to treatment, particularly in cases of temporal lobe epilepsy linked to hippocampal sclerosis (HS).
  • HS is classified into three subtypes based on where cell loss and gliosis occur: Type 1 (most common), Type 2, and Type 3, each varying in affected hippocampal areas.
  • The study reviews how different MRI techniques, both in vivo and ex vivo, can help correlate observed brain patterns with HS subtypes, finding that certain high-resolution MRIs combined with segmentation methods can effectively diagnose these subtypes, highlighting the need for improved techniques in future research.
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Methods to quantify cortical hyperexcitability are of enormous interest for mapping epileptic networks in patients with focal epilepsy. We hypothesize that, in the resting state, cortical hyperexcitability increases firing-rate correlations between neuronal populations within seizure onset zones (SOZs). This hypothesis predicts that in the gamma frequency band (40-200 Hz), amplitude envelope correlations (AECs), a relatively straightforward measure of functional connectivity, should be elevated within SOZs compared to other areas.

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Introduction: Low-grade epilepsy-associated tumors are the second most common histopathological diagnoses in cases of drug-resistant focal epilepsy. However, the connection between neuroimaging features and genetic alterations in these tumors is unclear, prompting an investigation into genotype-relevant neuroimaging characteristics.

Methods: This study retrospectively analyzed neuroimaging and surgical specimens from 46 epilepsy patients with low-grade epilepsy-associated neuroepithelial tumors that had genetic mutations identified through panel sequencing to investigate their relationship to genotypes.

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Introduction: Mesial temporal lobe epilepsy (MTLE) is one of the most prevalent forms of focal epilepsy in surgical series, particularly among adults. Over the decades, different surgical strategies have been developed to address drug-resistant epilepsy while safeguarding neurological and cognitive functions. Among these strategies, anterior temporal lobectomy (ATL), involving the removal of the temporal pole and mesial temporal structures, has emerged as a widely employed technique.

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