Current and Emerging Surgical Therapies for Severe Pediatric Epilepsies
Introduction
Nearly 30% of children with epilepsy have medically intractable seizures.1, 2, 3, 4 They are on multiple antiepileptic medications yet still suffer from seizures and associated debilitating conditions including developmental delay, cognitive decline, behavioral issues, psychosocial difficulties, and even physical injury during seizures. For these children, surgery often provides the best chance at seizure control.
According to the International League Against Epilepsy (ILAE) 2000 Standards, patients are considered medically refractory if they have “persistence of seizures despite adequate trial of anti-epileptic drugs (AEDs) with a minimum of two first-line drugs.”5 Overall, 2.9 million people in the United States alone have active epilepsy, including at least 450,000 children,6, 7 and approximately 800,000 have drug resistant, refractory epilepsy.2
Section snippets
Candidates for Epilepsy Surgery
Any patient with medically refractory epilepsy should be referred to a comprehensive epilepsy center to determine if they are a candidate for surgery. The most important determinant of a successful surgical outcome is good patient selection. Presurgical evaluation would try to determine the patientʼs seizure type and location of onset. The patient would undergo several days of constant electroencephalography (EEG) monitoring so that the epileptologists can study the seizure semiology.
In
Diagnostic Surgeries
When the location and borders of the epileptogenic lesion cannot be adequately determined with extracranial EEG, or if the epileptic focus appears very near to eloquent cortex, intracranial electrodes can provide vital information to determine if resection is safe and to guide the extent of resection. Subdural grids and strips or depth electrodes are placed over or in likely targets, and the patient is monitored in a video monitoring unit. Electrocorticography (ECoG) can determine the location
Resection
Once an epileptogenic focus is found, whether with noninvasive EEG and imaging, or through the use of intracranial electrodes, the patient can proceed to surgery. Temporal lobe resection is the most common procedure for epilepsy, including adult patients, and has a long record showing good rates of seizure freedom in carefully selected patients.
Temporal Lobe Epilepsy
In 2001, Wiebe et al16 published the first randomized controlled trial of anterior temporal lobectomy (ATL) vs. medical management for the treatment of
Corpus Callosotomy
Children who suffer from drop attacks may benefit from a corpus callosotomy in order to interrupt the spread of seizures. A callosotomy is intended as a palliative procedure, but about 75% of patients do notice a significant improvement in seizures.38, 39, 40 For some patients, their seizures change to a partial seizure that does not result in a fall, or they experience improvement in attention or language skills, so quality of life may significantly improve even if seizures persist.39, 40
Vagal Nerve Stimulators
Like the disconnection surgeries, the stimulation surgeries are generally more palliative than curative. Vagal nerve stimulation (VNS) delivers programmable scheduled intermittent electrical stimulation to the vagus nerve, and can be manually triggered to deliver a higher current when a patient is having a seizure to try to abort that seizure. The newest version of the generator (model 106) also offers heart rate detection with an option to provide increased stimulation in response to ictal
High Frequency Oscillations and Single-Pulse Electrical Stimulation
Successful resection of epileptic tissue requires accurate knowledge of the location and borders of that tissue. ECoG via intracranial electrodes monitors for epileptic spikes to determine if tissue should be removed. Recent studies have tried to refine the indicators to more accurately locate epileptic foci.
High frequency oscillations (HFOs) from 80-500 Hz, ictally and interictally, may correlate with epileptogenic zones.57, 58 HFOs may be more specific than spikes and might be able to more
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Cited by (15)
Localization of seizure onset zone with epilepsy propagation networks based on graph convolutional network
2022, Biomedical Signal Processing and ControlCitation Excerpt :Epilepsy is a common chronic neurological disorder. Nearly 30% of epilepsy patients are drug-resistant epilepsy and require surgical treatment [1,2]. In clinical practice, localization of the seizure onset zone (SOZ) is an important basis for surgical treatment of refractory focal epilepsy.
Seizure outcomes of large volume temporo-parieto-occipital and frontal surgery in children with drug-resistant epilepsy
2021, Epilepsy ResearchCitation Excerpt :Similarly, other factors such as gender and underlying pathologies do not relate in our analysis to seizure outcome. The small size of our samples and the heterogenous representation of the underlying conditions make it difficult to comment on any differences between pathologies; however, previous studies identified cortical dysplasia as a negative prognostic factor (Schmidt et al., 2004; Lee and Kim, 2013; Muh, 2016b), while neoplasia is more likely to result in favourable outcomes (Zaatreh et al., 2002; Schramm et al., 2001; Zentner et al., 1996). Pre-operative EEG reports did not appear to be predictive of outcomes.
Neuromodulation for the Treatment of Epilepsy: A Review of Current Approaches and Future Directions
2020, Clinical TherapeuticsCitation Excerpt :We omit a discussion of surgical selection because this is not our expertise and has been reviewed comprehensively elsewhere.76 Surgery does remain an important option for pediatric patients with drug-resistant epilepsy.77,78 In addition, it is noteworthy that current neuromodulatory approaches rarely achieve complete seizure freedom alone.
Laser interstitial thermotherapy (LiTT) in pediatric epilepsy surgery
2020, SeizureCitation Excerpt :Finally, (series of) open resections are a great burden for the affected children in cases of multiple epileptogenic foci like in TSC [15]. Several authors thus refer to the fact that the new stereotactic methods including LiTT exploit novel treatment options for new indications (e.g. [12,13,15,16]). One group has already moved to regard LiTT as the first-line therapy for HH [4].