Search

Objective: To determine the incidence rates of sudden unexpected death in epilepsy (SUDEP) in different epilepsy populations and address the question of whether risk factors for SUDEP have been identified. Methods: Systematic review of evidence; modified Grading Recommendations Assessment, Development and Evaluation process for developing conclusions; recommendations developed by consensus. Results: Findings for incidence rates based on 12 Class I studies include the following: SUDEP risk in children with epilepsy (aged 0-17 years) is 0.22/1,000 patient-years (95% CI 0.16-0.31) (high confidence in evidence). SUDEP risk increases in adults to 1.2/1,000 patient-years (95% CI 0.64-2.32) (low confidence in evidence). The major risk factor for SUDEP is the occurrence of generalized tonic-clonic seizures (GTCS); the SUDEP risk increases in association with increasing frequency of GTCS occurrence (high confidence in evidence). Recommendations: Level B: Clinicians caring for young children with epilepsy should inform parents/guardians that in 1 year, SUDEP typically affects 1 in 4,500 children; therefore, 4,499 of 4,500 children will not be affected. Clinicians should inform adult patients with epilepsy that SUDEP typically affects 1 in 1,000 adults with epilepsy per year; therefore, annually 999 of 1,000 adults will not be affected. For persons with epilepsy who continue to experience GTCS, clinicians should continue to actively manage epilepsy therapies to reduce seizures and SUDEP risk while incorporating patient preferences and weighing the risks and benefits of any new approach. Clinicians should inform persons with epilepsy that seizure freedom, particularly freedom from GTCS, is strongly associated with decreased SUDEP risk. [ABSTRACT FROM AUTHOR]

To study the role of magnetoencephalography (MEG) in the surgical evaluation of children with recurrent seizures after epilepsy surgery. We studied 17 children with recurrent seizures after epilepsy surgery using interictal and ictal scalp EEG, intracranial video EEG (IVEEG), MRI, and MEG. We analyzed the location and distribution of MEG spike sources (MEGSSs) and the relationship of MEGSSs to the margins of previous resections and surgical outcome. Clustered MEGSSs occurred at the margins of previous resections within two contiguous gyri in 10 patients (group A), extended spatially from a margin by ≤3 cm in three patients (group B), and were remote from a resection margin by >3 cm in six patients (group C). Two patients had concomitant group A and C clusters. Thirteen patients underwent second surgeries. IVEEG was used in four patients. Six of seven patients with group A MEGSS clusters did not require IVEEG for second surgeries. Follow-up periods ranged from 0.6 to 4.3 years (mean: 2.6 years). Eleven children, including eight who became seizure-free, achieved Engel class I or II. Our data demonstrate the utility of MEG for evaluating patients with recurrent seizures after epilepsy surgery. Specific MEGSS cluster patterns delineate epileptogenic zones. Removing cluster regions adjacent to the margins of previous resections, in addition to removing recurrent lesions, achieves favorable surgical outcome. Cluster location and extent identify which patients require IVEEG, potentially eliminating IVEEG for some. Patients with remotely located clusters require IVEEG for accurate assessment and localization of the entire epileptogenic zone. [ABSTRACT FROM AUTHOR]

Purpose: To characterize the spatial and temporal course of ictal high-frequency oscillations (HFOs) recorded by subdural EEG in children with intractable neocortical epilepsy. Methods: We retrospectively studied nine children (four girls, five boys; 4–17 yr) who presented with intractable extrahippocampal localization-related epilepsy and who underwent extraoperative video subdural EEG (1000 Hz sampling rate) and cortical resection. We performed multiple band frequency analysis (MBFA) to evaluate the frequency, time course, and distribution of ictal HFOs. We compared ictal HFO changes before and after clinical onset and postsurgical seizure outcomes. Results: Seventy-eight of 79 seizures showed HFOs. We observed wide-band HFOs (∼250Hz, ∼120 electrodes) in six patients either with partial seizures alone (three patients) or with epileptic spasms (three patients). Three patients with partial seizures that secondarily generalized had wide-band HFOs (∼170 Hz) before clinical onset and sustained narrow-band HFOs (60–164 Hz) with electrodecremental events after clinical onset (∼28 electrodes). In four postoperatively seizure-free patients, more electrodes recorded higher-frequency HFOs inside the resection area than outside before and after clinical seizure onset. In five patients with residual seizures, electrodes recorded more HFOs that were of higher or equal frequency outside the surgical area than inside after clinical onset. Conclusion: For partial seizures alone and epileptic spasms, more electrodes recorded only wide-band HFOs; for partial seizures that secondarily generalized, fewer electrodes recorded wide-band HFOs, but in these seizures electrodes also recorded subsequent sustained narrow-band ictal HFOs. Resection of those brain regions having electrodes with ictal, higher HFOs resulted in postsurgical seizure-free outcomes. [ABSTRACT FROM AUTHOR]

Purpose: To understand the rapid dynamic changes of ictal intracranial high-frequency oscillations (HFOs) in neocortical epilepsy. Methods: We integrated multiple band frequency analysis and brain-surface topographic maps of HFOs from ictal subdural EEG (SDEEG) recordings. We used SDEEG to record partial seizures consisting of right-arm jerks with secondary generalization in a 17-year-old right-handed girl. We selected 20-s EEG sections that included preclinical seizure recordings. We averaged the HFO power between 60 and 120 Hz for 25 selected electrodes, made topographic maps from these averaged powers, and superimposed the maps on the brain-surface image. We filmed consecutive HFO maps at a 10-ms frame rate. Results: Before clinical seizure onset, high-power HFOs emerged at the superior portion of the left precentral gyrus, then appeared in the middle of the left postcentral gyrus, and subsequently reverberated between both regions as well as the posterior portion of the left postcentral gyrus. Right-arm extension and facial grimacing started as the HFO power decreased. As generalized tonic–clonic seizures evolved, HFO power increased but remained within the central region. Conclusions: Topographic movies of intracranial HFOs on the brain surface allow visualization of the dynamic ictal changes in neocortical epilepsy. [ABSTRACT FROM AUTHOR]

Abstract Objective Limited evidence on the relationship between antiepileptic drug (AED) tapering and the likelihood of a seizure during an Epilepsy Monitoring Unit (EMU) admission is available, and no evidence specific to the pediatric population has been published. Our study sought to determine whether AED tapering leads to increased seizure likelihood in a pediatric EMU setting. Methods We performed a retrospective chart review of children admitted to the pediatric EMU at the Hospital for Sick Children in Toronto between June 1, 2014 and June 1, 2016. Data collected included demographics, reason for EMU referral, and epilepsy and medical characteristics. Among those with nondaily seizures, Kaplan–Meier curves were fit to compare probability of EMU seizure in those who were tapered fully from at least one AED to those not tapered. A Cox proportional hazards model was fit to evaluate this relationship after adjustment for subject sex, distance traveled to hospital, epilepsy duration, seizure frequency, time since last seizure, whether EMU referral was part of presurgical planning, magnetic resonance imaging (MRI) findings, and number of prescribed AEDs. An interaction between medication taper and number of prescribed AEDs was also included. Terms not significant at p < 0.3 were removed from the model, and the reduced model was recomputed. Results Of the 281 children included in the study, 159 had nondaily seizures. Kaplan–Meier curves indicated fully tapering at least one AED was associated with increased likelihood of seizure during EMU; however, after adjustment for confounding variables, this association was not preserved. Abnormal MRI findings, referral for presurgical evaluation, and shorter (≤ 3 months) time since last seizure were associated with increased likelihood of seizure during EMU. Significance Short-term AED tapering in pediatric patients may not be effective for increasing seizure likelihood in the EMU. Highlights • Evaluates the efficacy of AED tapering in a pediatric EMU setting • Fully tapering AED(s) in EMU patients was not associated with seizure likelihood. • Associated factors: MRI findings, presurgical referral, and time since last seizure [ABSTRACT FROM AUTHOR]

Highlights: [•] Annual percent of potentially eligible population who actually have surgery is only 1%. [•] Time from first seizure to EMU referral was approximately 4.6 years. [•] Time from EMU referral to surgery 1.6 years with iEEG and 1.1 years without iEEG. [•] Surgical patients: 95% reduced seizure frequency and 74% seizure free one year post-surgery. [ABSTRACT FROM AUTHOR]