Irene Elliott

Magnetoencephalographic localization in pediatric epilepsy surgery: Comparison with invasive intracranial electroencephalography

The object of this study was to determine the concordance of the anatomical location of interictal magnetoencephalographic (MEG) spike foci with the location of ictal onset zones identified by invasive ictal intracranial electroencephalographic recordings in children undergoing evaluation for epilepsy surgery. MEG was performed in 11 children with intractable, nonlesional, extratemporal, localization‐related epilepsy. Subsequently, chronic invasive intracranial electroencephalographic monitoring was performed by using subdural electrodes to localize the ictal onset zone and eloquent cortex. Based on the invasive monitoring data, all children had excision of, or multiple subpial transections through, ictal onset cortex and surrounding irritative zones. In 10 of 11 patients, the anatomical location of the epileptiform discharges as determined by MEG corresponded to the ictal onset zone established by ictal intracranial recordings. In all children, the anatomical location of the somatosensory hand area, determined by functional mapping through the subdural electrode array, was the same as that delineated by MEG. Nine of 11 patients became either seizure‐free or had a greater than 90% reduction in seizures after surgery, with a mean follow‐up of 24 months. MEG is a powerful and accurate tool in the presurgical evaluation of children with refractory nonlesional extratemporal epilepsy.

Dynamic Changes of Ictal High‐Frequency Oscillations in Neocortical Epilepsy: Using Multiple Band Frequency Analysis

Summary:  Purpose: To characterize the spatial and temporal course of ictal high‐frequency oscillations (HFOs) recorded by subdural EEG in children with intractable neocortical epilepsy.

MEG predicts epileptic zone in lesional extrahippocampal epilepsy: 12 pediatric surgery cases.

Summary:  Purpose: To discover whether the spatial distribution of spike sources determined by magnetoencephalography (MEG) provides reliable information for planning surgery and predicting outcomes in pediatric patients with lesional extrahippocampal epilepsy.

Focal resection of fast ripples on extraoperative intracranial EEG improves seizure outcome in pediatric epilepsy

Purpose:  High‐frequency oscillations (HFOs), termed ripples at 80–200 Hz and fast ripples (FRs) at >200/250 Hz, recorded by intracranial electroencephalography (EEG), may be a valuable surrogate marker for the localization of the epileptogenic zone. We evaluated the relationship of the resection of focal brain regions containing high‐rate interictal HFOs and the seizure‐onset zone (SOZ) determined by visual EEG analysis with the postsurgical seizure outcome, using extraoperative intracranial EEG monitoring in pediatric patients and automated HFO detection.

Cognitive, psychosocial, and family function One year after pediatric epilepsy surgery

Summary:  Purpose: Assumptions regarding the benefits of seizure control after pediatric epilepsy surgery for cognitive, psychosocial, and family function were explored in a prospective study of 51 children with intractable epilepsy.

I just want to be normal: A qualitative study exploring how children and adolescents view the impact of intractable epilepsy on their quality of life

This qualitative study explores how children and adolescents with medically refractory seizures experience the impact of epilepsy on their quality of life (QOL) within the domains of physical, emotional/behavioral, social, and cognitive/academic function. Semi-structured, open-ended interviews were conducted with 49 participants (7-18 years old). These narratives constituted our data source. Analyses involved inductive generation of themes/subthemes and connection of these themes to generate a theoretical representation of their relationships. These themes reflected the negative impact of epilepsy on QOL: physical-excessive fatigue as a barrier to academic and social pursuits; emotional/behavioral-intermittent emotional distress heightened by epilepsy-related factors such as unpredictability of seizures; social-profound social isolation; and cognitive/academic-discontinuous, fragmented learning. Youths perceive seizures as the major barrier to their sense of normalcy, setting them apart from others. Findings provide direction for assessment and evidence for developing or enhancing clinical interventions and community/school-based programs that might mitigate some of these negative experiences.

Temporal lobe surgery for intractable epilepsy in children: an analysis of outcomes in 126 children.

OBJECTIVETemporal lobectomy is a well-established neurosurgical procedure for temporal lobe epilepsy. In this study, we conducted a retrospective review of children with drug-resistant temporal lobe epilepsy to evaluate seizure outcome after temporal lobe surgery. METHODSWe reviewed the medical records of 126 children who had surgery for temporal lobe epilepsy at The Hospital for Sick Children between 1983 and 2003. The records were examined for preoperative and intraoperative factors that could predict patient outcome after surgery. RESULTSThe mean age at seizure onset was 5.9 years. The mean seizure duration before surgery was 5.6 years. All patients had preoperative computed tomographic scans, magnetic resonance imaging scans, or both. The mean age at the time of surgery was 13.5 years. Sixty-two patients underwent left temporal resections and 64 patients underwent right temporal resections. The histopathology of the temporal resections revealed low-grade brain tumors in 65 children (52%) and cavernous malformations in four children. Ganglioglioma and astrocytoma were the most common tumors encountered. Mesial temporal sclerosis was found in 16 patients (13%), astrogliosis in 15 patients (12%), and cortical dysplasia in eight patients (7%). Postoperative follow-up of at least 2 years was available for 106 patients and ranged up to 13.0 years. Seventy-four percent of patients had an Engel Class I or II outcome. Patients with temporal lobe lesions had better outcomes compared with those without lesions (P < 0.05). Patients without a history of secondary generalization of seizures also had a better outcome when compared with those with secondary generalization. Complications in the form of contralateral homonymous hemianopsia, dysphasia, and infection were found in 5% of patients. Twelve patients had a second temporal lobe procedure for intractable recurrent seizures. After a second procedure, seven patients returned to a seizure-free state. CONCLUSIONTemporal lobe resections for epilepsy in children are effective and safe procedures, with a favorable impact on seizure control. Repeat temporal resections for recurrent seizures may also be effective in restoring a seizure-free outcome to children.

Cognitive Skills in Children with Intractable Epilepsy: Comparison of Surgical and Nonsurgical Candidates

Summary:  Purpose: To compare neuropsychological performance of two groups of children with intractable epilepsy: those who are surgical candidates, and those who are not.

Confirmation of two magnetoencephalographic epileptic foci by invasive monitoring from subdural electrodes in an adolescent with right frontocentral epilepsy.

Summary: Purpose: To report our evaluation of interictal two epileptic spike fields on magnetoencephalography (MEG) by using invasive intracranial monitoring in a patient without lesion on magnetic resonance imaging (MRI).

Utility of Magnetoencephalography in the Evaluation of Recurrent Seizures after Epilepsy Surgery

Purpose: To study the role of magnetoencephalography (MEG) in the surgical evaluation of children with recurrent seizures after epilepsy surgery.