- Department of Neurosurgery, Division of Pediatric Neurosurgery, Baylor College of Medicine/Texas Children’s Hospital, Houston, Texas,
- Department of Neurosurgery, Division of Pediatric Neurosurgery, Northwestern University Feinberg School of Medicine/Ann and Robert H Lurie Children’s Hospital, Chicago, IL, USA.
Sandi K. Lam
Department of Neurosurgery, Division of Pediatric Neurosurgery, Northwestern University Feinberg School of Medicine/Ann and Robert H Lurie Children’s Hospital, Chicago, IL, USA.
DOI:10.25259/SNI_418_2019Copyright: © 2019 Surgical Neurology International This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-Share Alike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms.
How to cite this article: Nisha Gadgil, Matthew Muir, Melissa A. Lopresti, Sandi K. Lam. An update on pediatric surgical epilepsy: Part II. 27-Dec-2019;10:258
How to cite this URL: Nisha Gadgil, Matthew Muir, Melissa A. Lopresti, Sandi K. Lam. An update on pediatric surgical epilepsy: Part II. 27-Dec-2019;10:258. Available from: https://surgicalneurologyint.com/surgicalint-articles/9820/
Background: Recent advances may allow surgical options for pediatric patients with refractory epilepsy not previously deemed surgical candidates. This review outlines major technological developments in the field of pediatric surgical epilepsy.
Methods: The literature was comprehensively reviewed and summarized pertaining to stereotactic electroencephalography (sEEG), laser ablation, focused ultrasound (FUS), responsive neurostimulation (RNS), and deep brain stimulation (DBS) in pediatric epilepsy patients.
Results: sEEG allows improved seizure localization in patients with widespread, bilateral, or deep-seated epileptic foci. Laser ablation may be used for destruction of deep-seated epileptic foci close to eloquent structures; FUS has a similar potential application. RNS is a palliative option for patients with eloquent, multiple, or broad epileptogenic foci. DBS is another palliative approach in children unsuitable for respective surgery.
Conclusion: The landscape of pediatric epilepsy is changing due to improved diagnostic and treatment options for patients with refractory seizures. These interventions may improve seizure outcomes and decrease surgical morbidity, though further research is needed to define the appropriate role for each modality.
Keywords: Epilepsy surgery, Innovation, Minimally invasive, Pediatric, Technology
Pediatric epilepsy has a worldwide prevalence of 1%, and 20–30% are diagnosed with drug-resistant epilepsy (DRE) (persistent seizures despite treatment with two first-line antiepileptic medications).[
Recent developments allow surgical options for patients previously not deemed candidates, such as those with bilateral, deep, eloquent, or poorly localizing epileptogenic foci. The American Academy of Neurology now recommends early surgery for select patients with DRE. Nevertheless, there is still substantial delay between diagnosis and surgical referral.[
Complete removal of the epileptogenic zone (EZ) is the most important factor associated with postsurgical seizure freedom. Accurate localization of the EZ is therefore critical, as is information obtained from semiology, EEG, structural magnetic resonance imaging (MRI), and other advanced testing.[
There are two main types of intracranial electrode monitoring: subdural strip/grid recordings, and stereotactically placed depth electrodes implanted through burr holes (sEEG). Robotic assistance has a 1–3 mm level of accuracy for placement of electrodes and allows safe trajectories with reduced operating time [
Patients with DRE may be considered for sEEG in the following situations: no structural lesion identified on MRI and scalp EEG nonlocalizing, suspected multifocal/multilesional epilepsy, conflicting noninvasive data, suspected widespread seizure network, or EZ in close proximity to eloquent structures.[
sEEG is a minimally invasive approach for seizure localization that provides significant advantages over subdural electrodes such as sampling of extended regions, interrogation of deep structures not accessible to subdural electrodes,[
After the seizure focus has been appropriately localized, there are multiple surgical options, including open surgical resection and minimally invasive stereotactic techniques such as radiofrequency thermo-coagulation and stereotactic radiosurgery. However, radiofrequency thermo-coagulation does not allow real-time monitoring of tissue destruction and is less effective than open microsurgical resection.[
MR-guided LITT is used to treat mesial temporal sclerosis, hypothalamic hamartoma, and deep periventricular lesions.[
In pediatrics, hypothalamic hamartoma is the most frequently reported indication for LITT, allowing disconnection of these deep-seated lesions while avoiding damage to surrounding structures [
Intraoperative T2-weighted coronal magnetic resonance imaging of a child undergoing laser ablation for intractable gelastic epilepsy resulting from hypothalamic hamartoma. The laser cannula is in place with the tip terminating in the hamartoma, allowing focused delivery of heat that can be monitored in real-time using magnetic resonance thermography.
FUS is another minimally invasive modality used to create targeted tissue ablation by delivering high-intensity ultrasound waves through external transducer elements which cause irreversible coagulation. FUS creates a 2–6 mm diameter intracranial lesion with 1 mm precision. Tissue ablation can be monitored in real-time using MR thermography. FUS avoids the need for skin incision or burr holes and carries a reduced complication rate compared to open microsurgery or LITT.[
The current primary application of FUS is for treating essential tremor, Parkinson’s disease, and neuropathic pain, and more recently, deep brain tumors.[
RNS adapts therapeutic stimulation in response to a continuous feedback loop. Depth or strip electrodes within the ictal onset zone continuously monitor electrocorticography activity; the device uses a programmed algorithm to detect incipient seizures. Once an abnormal activity is detected, the device supplies responsive therapeutic electrical stimulation designed to reduce or abort the seizures.[
NeuroPace RNS (Neuropace, Mountain View, CA) is the first and only FDA-approved RNS device available to patients aged 18 years or older.[
RNS has been used off-label in pediatric patients with DRE in those with no surgical resection options (bilateral or eloquent epileptogenic foci).[
An example of RNS placement is demonstrated in
DBS is an open-loop neuromodulatory program that involves the delivery of electrical stimulation to deep brain structures through implanted electrodes connected to a pulse generator. The safety profile is similar to DBS for movement disorders.[
Advances in diagnostic capabilities and minimally invasive treatments, including stereotaxy, surgical robotics, laser ablation, and neurostimulation may improve seizure outcomes while minimizing surgical morbidity.
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