Impact of seizure onset zone and intracranial electroencephalography ictal characteristics on epilepsy surgery outcomes in tuberous sclerosis complex.

Ninety percent of tuberous sclerosis complex (TSC) patients have seizures, with ∼50 % developing drug refractory epilepsy. Surgical intervention aims to remove the seizure onset zone (SOZ). This retrospective study investigated the relationship of SOZ size, ictal pattern, and extent of resection with surgical outcomes.

Emotional facial expression and perioral motor functions of the human auditory cortex.

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.

Neuronal Circuits Supporting Development of Visual Naming Revealed by Intracranial Coherence Modulations.

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.

A distributed network supports spatiotemporal cerebral dynamics of visual naming.

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.

Subtraction ictal SPECT co-registered to MRI (SISCOM) patterns in children with temporal lobe epilepsy.

Objective: We evaluated SISCOM patterns and their relationship with surgical outcome in children with temporal lobe epilepsy (TLE) who had undergone a temporal lobe surgery.

Methods: This was an observational study evaluating SISCOM patterns in 40 children with TLE. We classified SISCOM patterns into 4 categories; (i) unilateral anteromesial and/or anterolateral temporal pattern; (ii) unilateral anteromesial and/or anterolateral temporal plus posterior extension pattern; (iii) bilateral anteromesial and/or anterolateral temporal pattern; and (iv) atypical pattern.

Fast Automated Stereo-EEG Electrode Contact Identification and Labeling Ensemble.

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.

High-gamma modulation language mapping with stereo-EEG: A novel analytic approach and diagnostic validation.

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.

Electrical stimulation sensorimotor mapping with stereo-EEG.

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.

Electrical stimulation mapping of language with stereo-EEG.

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.

Development of information sharing in language neocortex in childhood-onset drug-resistant epilepsy.

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.

Neuropsychological outcomes after resection of cortical sites with visual naming associated electrocorticographic high-gamma modulation.

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.

Impact of radiotracer injection latency and seizure duration on subtraction ictal SPECT co-registered to MRI (SISCOM) performance in children.

Objective: We evaluated the impact of radiotracer injection latency and post-injection seizure duration on subtraction ictal SPECT co-registered to MRI (SISCOM) test performance in identifying the epileptogenic zone (EZ) in children with drug-resistant epilepsy who had undergone a resective epilepsy surgery.

Methods: SISCOM concordance with the EZ was retrospectively reviewed to evaluate its performance in 113 children. The impact of radiotracer injection latency and post-injection seizure duration was evaluated for their predictive value of SISCOM localization accuracy.

Ictal connectivity in childhood absence epilepsy: Associations with outcome.

Objective: The understanding of childhood absence epilepsy (CAE) has been revolutionized over the past decade, but the biological mechanisms responsible for variable treatment outcomes are unknown. Our purpose in this prospective observational study was to determine how pretreatment ictal network pathways, defined using a combined electroencephalography (EEG)-functional magnetic resonance imaging (EEG-fMRI) and magnetoencephalography (MEG) effective connectivity analysis, were related to treatment response.

Methods: Sixteen children with newly diagnosed and drug-naive CAE had 31 typical absence seizures during EEG-fMRI and 74 during MEG.

Presurgical language localization with visual naming associated ECoG high- gamma modulation in pediatric drug-resistant epilepsy.

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.

Clinical factors predict surgical outcomes in pediatric MRI-negative drug-resistant epilepsy.

Purpose: Lack of a potentially epileptogenic lesion on brain magnetic resonance imaging (MRI) is a poor prognostic marker for epilepsy surgery. We present a single-center series of childhood-onset MRI-negative drug-resistant epilepsy (DRE) and analyze surgical outcomes and predictors.

Methods: Children with MRI-negative DRE who had resective surgery from January 2007 to December 2013 were identified using an institutional database.

Prospective detection of cortical dysplasia on clinical MRI in pediatric intractable epilepsy.

Background: Cortical dysplasia is the most common cause of pediatric refractory epilepsy. MRI detection of epileptogenic lesion is associated with good postsurgical outcome. Additional electrophysiological information is suggested to be helpful in localization of cortical dysplasia.

Long-term outcomes of resective epilepsy surgery after invasive presurgical evaluation in children with tuberous sclerosis complex and bilateral multiple lesions.

Object: Tuberous sclerosis complex (TSC) with medically refractory epilepsy is characterized by multifocal brain abnormalities, traditionally indicating poor surgical candidacy. This single-center, retrospective study appraised seizurerelated, neuropsychological, and other outcomes of resective surgery in TSC patients with medically refractory epilepsy, and analyzed predictors for these outcomes.

Methods: Patients with multilesional TSC who underwent epilepsy surgery between 2007 and 2012 were identified from an electronic database.

Cerebral glucose hypometabolism is associated with mitochondrial dysfunction in patients with intractable epilepsy and cortical dysplasia.

Objectives: Metabolic imaging studies, such as positron emission tomography (PET), allow for an assessment of physiologic functioning of the brain, and [(18)F]fluoro-2-deoxyglucose (FDG)-PET is now a commonly used technique in presurgical epilepsy evaluations. Focal interictal decreases in glucose consumption are often but inconsistently concordant with the ictal onset area, and the underlying mechanisms are poorly understood. The current study tests the hypothesis that areas of glucose hypometabolism, determined by FDG-PET, are associated with mitochondrial dysfunction in patients with medically intractable epilepsy associated with isolated focal cortical dysplasia (FCD).

Real-time functional mapping with electrocorticography in pediatric epilepsy: comparison with fMRI and ESM findings.

SIGFRIED (SIGnal modeling For Real-time Identification and Event Detection) software provides real-time functional mapping (RTFM) of eloquent cortex for epilepsy patients preparing to undergo resective surgery. This study presents the first application of paradigms used in functional magnetic resonance (fMRI) and electrical cortical stimulation mapping (ESM) studies for shared functional cortical mapping in the context of RTFM. Results from the 3 modalities are compared.

Bereitschaft (readiness potential) and supplemental motor area interaction in movement generation: spinal cord injury and normal subjects.

The readiness potential (BP) consists of movement-related cortical potentials (MRCPs) peaking in the motor potential (MP). Our objective was to better understand the role of the BP and MP in the production of voluntary movements and to help define the relative roles of the supplementary motor area (SMA) and the BP in the generation of self-paced and passive finger movements. The ultimate goal was to relate the BP (or the SMA) to external devices via conversion of potentials to a language "understood" by the receiving devices.