Identification of Negative BOLD Responses in Epilepsy Using Windkessel Models.

Alongside positive blood oxygenation level-dependent (BOLD) responses associated with interictal epileptic discharges, a variety of negative BOLD responses (NBRs) are typically found in epileptic patients. Previous studies suggest that, in general, up to four mechanisms might underlie the genesis of NBRs in the brain: (i) neuronal disruption of network activity, (ii) altered balance of neurometabolic/vascular couplings, (iii) arterial blood stealing, and (iv) enhanced cortical inhibition. Detecting and classifying these mechanisms from BOLD signals are pivotal for the improvement of the specificity of the electroencephalography-functional magnetic resonance imaging (EEG-fMRI) image modality to identify the seizure-onset zones in refractory local epilepsy.

The diagnostic utility of 3D-ESI rotating and moving dipole methodology in the pre-surgical evaluation of MRI-negative childhood epilepsy due to focal cortical dysplasia.

Objective: This study investigates whether a combined rotating dipole (RD) and moving dipole (MD) solution enhances three-dimensional electroencephalography (EEG) source imaging (3D-ESI) localization in magnetic resonance imaging (MRI)-negative pediatric patients with focal cortical dysplasia (FCD).

Methods: We retrospectively selected 14 MRI-negative patients with FCD from a cohort of 60 pediatric patients previously used to evaluate the diagnostic utility of 3D-ESI in epilepsy surgery. Patients were younger than 18 years at time of surgery and had at least 1 year of outcome data.

The diagnostic utility of 3D electroencephalography source imaging in pediatric epilepsy surgery.

Objective: The aim of this study was to investigate the utility of three-dimensional electroencephalography source imaging (3D-ESI) with low-resolution electroencephalographic data in the pediatric noninvasive presurgical evaluation, and to compare the findings with positron emission tomography (PET) and ictal single-photon emission computed tomography (iSPECT).

Methods: We retrospectively selected 60 patients from a database of 594 patients who underwent excisional surgery for drug-resistant epilepsy. Patients were <18 years at time of surgery, had at least one presurgical volumetric brain magnetic resonance imaging (MRI), and at least 1 year of outcome data.

The diagnostic utility of intracranial EEG monitoring for epilepsy surgery in children.

Objective: There are limited data on the indications for the use of chronic invasive electroencephalography (EEG) monitoring (IEM) for pediatric epilepsy surgery.

Methods: We retrospectively studied 102 children who underwent intracranial monitoring to map critical cortex, localize the epileptogenic region, or resolve divergent findings. We assessed IEM utility based on changes to the resection plan following analysis of noninvasive data.

Low-grade focal cortical dysplasia is associated with prenatal and perinatal brain injury.

Purpose: Prenatal and perinatal adverse events are reported to have a pathogenetic role in focal cortical dysplasia (FCD). However, no data are available regarding the prevalence and significance of this association. A cohort of children with significant prenatal and perinatal brain injury and histologically proven mild malformations of cortical development (mMCD) or FCD was analyzed.

Agenesis of the arcuate fasciculi in congenital bilateral perisylvian syndrome: a diffusion tensor imaging and tractography study.

Objective: To describe the absence of the arcuate fasciculi in 2 cases of congenital bilateral perisylvian syndrome (CBPS).

Design: Case series.

Setting: Pediatric referral hospital-based study.

Different features of histopathological subtypes of pediatric focal cortical dysplasia.

Objective: Focal cortical dysplasia (FCD) is the most frequent pathological finding in pediatric epilepsy surgery patients. Several histopathological types of FCD are distinguished. The aim of the study was to define distinctive features of FCD subtypes.

Epilepsy surgery in patients with normal or nonfocal MRI scans: integrative strategies offer long-term seizure relief.

Purpose: Excisional surgery achieves seizure freedom in a large proportion of children with intractable lesional epilepsy, but the outcome for children without a focal lesion on MRI is less clear. We report the outcome of a cohort predominantly of children with nonlesional intractable partial epilepsy undergoing resective surgery.

Methods: We studied 102 patients with nonlesional intractable partial epilepsy who underwent excisional surgery.

Near infrared spectroscopy in the management of status epilepticus in a young infant.

We report the medication management of electroencephalographic status epilepticus with subtle clinical manifestations in a young infant while simultaneously recording electroencephalographic activity and cerebral regional oxygen saturation (rSO(2)) index using near infrared spectroscopy (NIRS). We found that antiepileptic drugs equally influence the frequency of rSO(2) index fluctuations and electroencephalographic seizures. The purpose of this report is to illustrate the use of NIRS in the medication management of an infant with status epilepticus and subtle or no clinical manifestations; and to suggest that if future studies confirm our finding, NIRS may be reliably used to gauge the effects of antiepileptic medications in similar patients.

Near-infrared spectroscopy to define cognitive frontal lobe functions.

Near-infrared spectroscopy (NIRS) monitors changes in the regional cerebral oxygenation (rSO) and has been used to study cerebral physiologic functions in normal states and during epileptic seizures. Yet, the limitations and pitfalls of the technique are not fully understood. The authors evaluated NIRS changes over the frontal lobes during language tasks known to be associated with the integrity of the dominant frontal lobe in 17 normal adults (handedness: 14 right, 3 left).

Surgical outcomes and seizure control rates after resection of dysembryoplastic neuroepithelial tumors.

Object: In this study the authors review the outcomes in pediatric patients who presented with seizures and underwent resection of dysembryoplastic neuroepithelial tumors (DNETs). The authors focus on the diagnostic evaluation and surgical techniques that facilitate gross-total tumor resection and subsequent freedom from seizures.

Methods: Eighteen patients between the ages of 1 month and 13 years who presented with seizures underwent resection of DNETs between January 1992 and December 2004.

Seizure disorders: functional MR imaging for diagnostic evaluation and surgical treatment--prospective study.

Purpose: To prospectively evaluate effect of functional magnetic resonance (MR) imaging on diagnostic work-up and treatment planning in patients with seizure disorders who are candidates for surgical treatment.

Materials And Methods: Institutional review board approval was obtained; informed consent was obtained either from the patient or the parent or guardian in all patients. This study was conducted with Health Insurance Portability and Accountability Act compliance.

Surgery for epilepsy due to cortical malformations: ten-year follow-up.

Children with malformations of cortical development represent a significant proportion of pediatric epilepsy surgery candidates. From a cohort of 40 children operated on between 1980 and 1992 with malformation of cortical development, 38 were alive and had data 10 years after surgery. Age at surgery ranged from 6 months to 18 years (mean, 9.

Cerebral regional oxygen fluctuations and decline during clinically silent focal electroencephalographic seizures in a neonate.

We describe a neonate with tuberous sclerosis complex and right frontal cortical dysplasia who underwent simultaneous near-infrared spectroscopy and electroencephalography (EEG) during repetitive clinically silent right frontal EEG seizures. The seizures produced a progressive decline in regional oxygen saturation index and wider regional oxygen saturation index fluctuations in the right hemisphere than in the left hemisphere. We conclude that recurrent clinically silent focal EEG seizures in this neonate were associated with lateralizing near-infrared spectroscopy changes suggestive of relative cerebral hypoxia.

The use of stereotactic radiosurgery to treat intractable childhood partial epilepsy.

Purpose: Although conventional surgery is presently used to treat seizures of temporolimbic and neocortical origin, deep-seated lesions are often associated with morbidity. Stereotactic radiosurgery is a noninvasive procedure that effectively treats patients with vascular malformations and brain tumors, but its efficacy for epileptogenic foci is limited, especially in children.

Methods: Between 1995 and 1999, four candidates who had medically uncontrolled seizures and localized seizure foci were selected for stereotactic radiosurgery, with a mean age of 9.