Publications by authors named "Jason Buroker"

Article Synopsis
  • The study investigates how different areas of the cerebral cortex exhibit varying daily rhythms of high-frequency oscillations (HFOs) in patients with drug-resistant epilepsy.
  • Stereotactic electroencephalography (EEG) was used to analyze HFOs across different brain regions, while filtering out data affected by seizures or artifacts.
  • Five distinct clusters were identified based on HFO patterns, which aligned with specific resting-state brain networks, suggesting a link between time-of-day variations in brain activity and functional connectivity.
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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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Objective: We investigated the role of transverse temporal gyrus and adjacent cortex (TTG+) in facial expressions and perioral movements.

Methods: In 31 patients undergoing stereo-electroencephalography monitoring, we describe behavioral responses elicited by electrical stimulation within the TTG+. Task-induced high-gamma modulation (HGM), auditory evoked responses, and resting-state connectivity were used to investigate the cortical sites having different types of responses on electrical stimulation.

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Objective: Seizures are known to occur with diurnal and other rhythms. To gain insight into the neurophysiology of periodicity of seizures, we tested the hypothesis that intracranial high-frequency oscillations (HFOs) show diurnal rhythms and sleep-wake cycle variation. We further hypothesized that HFOs have different rhythms within and outside the seizure-onset zone (SOZ).

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Background: Improvement in visual naming abilities throughout the childhood and adolescence supports development of higher-order linguistic skills. We investigated neuronal circuits underlying improvement in the speed of visual naming with age, and age-related dynamics of these circuits.

Methods: Response times were electronically measured during an overt visual naming task in epilepsy patients undergoing stereo-EEG monitoring.

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Objective: Cerebral spatiotemporal dynamics of visual naming were investigated in epilepsy patients undergoing stereo-electroencephalography (SEEG) monitoring.

Methods: Brain networks were defined by Parcel-Activation-Resection-Symptom matching (PARS) approach by matching high-gamma (50-150 Hz) modulations (HGM) in neuroanatomic parcels during visual naming, with neuropsychological outcomes after resection/ablation of those parcels. Brain parcels with >50% electrode contacts simultaneously showing significant HGM were aligned, to delineate spatiotemporal course of naming-related HGM.

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Introduction: Stereotactic electroencephalography (SEEG) has emerged as the preferred modality for intracranial monitoring in drug-resistant epilepsy (DRE) patients being evaluated for neurosurgery. After implantation of SEEG electrodes, it is important to determine the neuroanatomic locations of electrode contacts (ECs), to localize ictal onset and propagation, and integrate functional information to facilitate surgical decisions. Although there are tools for coregistration of preoperative MRI and postoperative CT scans, identification, sorting, and labeling of SEEG ECs is often performed manually, which is resource intensive.

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Objective: A novel analytic approach for task-related high-gamma modulation (HGM) in stereo-electroencephalography (SEEG) was developed and evaluated for language mapping.

Methods: SEEG signals, acquired from drug-resistant epilepsy patients during a visual naming task, were analyzed to find clusters of 50-150 Hz power modulations in time-frequency domain. Classifier models to identify electrode contacts within the reference neuroanatomy and electrical stimulation mapping (ESM) speech/language sites were developed and validated.

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Objective: We evaluated stereo-EEG electrical stimulation mapping (ESM) for localization of anatomic sensorimotor parcels in pediatric patients with drug-resistant epilepsy. We also analyzed sensorimotor and after-discharge thresholds, and the somatotopy of sensorimotor responses.

Methods: ESM was performed with 50 Hz, biphasic, 2-3 s trains, using 1-9 mA current.

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Objective: We prospectively validated stereo-electroencephalography (EEG) electrical stimulation mapping (ESM) of language against a reference standard of meta-analytic functional magnetic resonance imaging (fMRI) framework (Neurosynth).

Methods: Language ESM was performed using 50 Hz, biphasic, bipolar, stimulation at 1-8 mA, with a picture naming task. Electrode contacts (ECs) were scored as ESM+ if ESM interfered with speech/language function.

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Objective: We studied age-related dynamics of information sharing among cortical language regions with electrocorticographic high-gamma modulation during picture-naming and story-listening tasks.

Methods: Seventeen epilepsy patients aged 4-19 years, undergoing extraoperative monitoring with left-hemispheric subdural electrodes, were included. Mutual information (MI), a nondirectional measure of shared information, between 16 pairs of cortical regions of interest, was computed from trial-averaged 70-150 Hz power modulations during language tasks.

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Background: Language mapping with high-gamma modulation (HGM) has compared well with electrical cortical stimulation mapping (ESM). However, there is limited prospective data about its functional validity. We compared changes in neuropsychological evaluation (NPE) performed before and 1-year after epilepsy surgery, between patients with/without resection of cortical sites showing HGM during a visual naming task.

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Article Synopsis
  • - This study compared high-gamma modulation (HGM) during a story-listening task to conventional electrical stimulation mapping (ESM) for identifying language areas in children with drug-resistant epilepsy who were undergoing brain monitoring.
  • - Results showed that HGM could effectively pinpoint language locations in the left hemisphere with high specificity and accuracy, especially when combined with a visual naming task, outperforming ESM in some aspects.
  • - This suggests that HGM from passive listening can be a valuable tool for presurgical language mapping in pediatric patients, enhancing the understanding of language localization in the brain.
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Objective: This prospective study compared presurgical language localization with visual naming-associated high-γ modulation (HGM) and conventional electrical cortical stimulation (ECS) in children with intracranial electrodes.

Methods: Patients with drug-resistant epilepsy who were undergoing intracranial monitoring were included if able to name pictures. Electrocorticography (ECoG) signals were recorded during picture naming (overt and covert) and quiet baseline.

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Introduction: This study describes development of a novel language mapping approach using high-γ modulation in electrocorticograph (ECoG) during spontaneous conversation, and its comparison with electrical cortical stimulation (ECS) in childhood-onset drug-resistant epilepsy.

Methods: Patients undergoing invasive pre-surgical monitoring and able to converse with the investigator were eligible. ECoG signals and synchronized audio were acquired during quiet baseline and during natural conversation between investigator and the patient.

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