Technical aspects of pediatric epilepsy surgery: Report of a multicenter, multinational web‐based survey by the ILAE Task Force on Pediatric Epilepsy Surgery

Abstract

SUMMARYSurgical techniques may vary extensively between centers. We report on a web-based survey aimed at evaluating the current technical approaches in different centers around the world performing epilepsy surgery in children. The intention of the survey was to establish technical standards. A request was made to 88 centers to complete a web-based survey comprising 51 questions. There were 14 questions related to general issues, 13 questions investigating the different technical aspects for children undergoing epilepsy surgery, and 24 questions investigating surgical strategies in pediatric epilepsy surgery. Fifty-two centers covering a wide geographic representation completed the questionnaire. The median number of resective procedures per center per year was 47. Some important technical practices appeared (>80% of the responses) such as the use of prophylactic antibiotics (98%), the use of high-speed drills for bone opening (88%), nonresorbable material for bone flap closure (85%), head fixation (90%), use of the surgical microscope (100%), and of free bone flaps. Other questions, such as the use of drains, electrocorticography (ECoG) and preoperative withdrawal of valproate, led to mixed, inconclusive results. Complications were noted in 3.8% of the patients submitted to cortical resection, 9.9% hemispheric surgery, 5% callosotomy, 1.8% depth electrode implantation, 5.9% subdural grids implantation, 11.9% hypothalamic hamartoma resection, 0.9% vagus nerve stimulation (VNS), and 0.5% deep brain stimulation. There were no major differences across regions or countries in any of the subitems above. The present data offer the first overview of the technical aspects of pediatric epilepsy surgery worldwide. Surprisingly, there seem to be more similarities than differences. That aside many of the evaluated issues should be examined by adequately designed multicenter randomized controlled trials (RCTs). Further knowledge on these technical issues might lead to increased standardization and lower costs in the future, as well as definitive practice guidelines.

Unilobar surgery for symptomatic epileptic spasms

“…In previous series most patients with spasms achieving seizure freedom received multilobar or hemispheric resections/disconnections . Our results suggest that unilobar procedures, which carry lower rates of complications and postsurgical deficits compared to multilobar or hemispheric resections/disconnections, are effective in selected patients.…”

Subtraction Ictal SPECT coregistered to MRI (SISCOM) as a guide in localizing childhood epilepsy

“…Finally, the EZ does not always correspond to (or is not limited to) the epileptogenic lesion . At present, the gold standard for the identification of the EZ is invasive EEG . However, placement of intracranial and in particular subdural electrodes has a considerable burden of perioperative complications and several limitations in children .…”

“…10 At present, the gold standard for the identification of the EZ is invasive EEG. 11 However, placement of intracranial and in particular subdural electrodes has a considerable burden of perioperative complications and several limitations in children. 12 For these reasons, validation of noninvasive imaging techniques applied to the pediatric population for the identification of the EZ is essential.…”

Extratemporal resections in pediatric epilepsy surgery—an overview

“…The next step of localization incorporates a battery of functional imaging tests (e.g., ictal‐single‐photon emission computed tomography [SPECT/]/subtraction ictal spect co‐registered to MRI [SISCOM], magnetoencephalography [MEG], positron emission tomography [PET]) that serve to distinguish regions of hyperexcitability from background and thereby implicate possible regions of epileptogenesis. There are preferences between centers with regard to the number and choice of studies, but the unifying concept is that functional imaging studies sufficiently define regions of epileptogenesis to enable lateralization and localization of epileptogenic activity …”