High frequency oscillations in the intra-operative ECoG to guide epilepsy surgery ("The HFO Trial"): study protocol for a randomized controlled trial

作者：Klooster Maryse A van 't^*; Leijten Frans S S; Huiskamp Geertjan; Ronner Hanneke E; Baayen Johannes C; van Rijen Peter C; Eijkemans Martinus J C; Braun Kees P J; Zijlmans Maeike

来源：Trials, 2015, 16(1): 422.

DOI：10.1186/s13063-015-0932-6

• Epilepsy surgery
• Intra-operative electrocorticography
• ECoG
• Pediatric epilepsy
• Epileptogenic zone
• High frequency oscillations
• HFOs
• Randomized controlled trial

Background: Intra-operative electrocorticography, based on interictal spikes and spike patterns, is performed to optimize delineation of the epileptogenic tissue during epilepsy surgery. High frequency oscillations (HFOs, 80-500 Hz) have been identified as more precise biomarkers for epileptogenic tissue. The aim of the trial is to determine prospectively if ioECoG-tailored surgery using HFOs, instead of interictal spikes, is feasible and will lead to an equal or better seizure outcome.
Methods\Design: We present a single-blinded multi-center randomized controlled trial "The HFO Trial" including patients with refractory focal epilepsy of all ages who undergo surgery with intra-operative electrocorticography. Surgery is tailored by HFOs (arm 1) or interictal spikes (arm 2) in the intra-operative electrocorticography. Primary outcome is post-operative outcome after 1 year, dichotomized in seizure freedom (Engel 1A and 1B) versus seizure recurrence (Engel 1C-4). Secondary outcome measures are the volume of resected tissue, neurologic deficits, surgical duration and complications, cognition and quality of life. The trial has a non-inferiority design to test feasibility and at least equal performance in terms of surgical outcome. We aim to include 78 patients within 3 years including 1 year follow-up. Results are expected in 2018.
Discussion: This trial provides a transition from observational research towards clinical interventions using HFOs. We address methodological difficulties in designing this trial. We expect that the use of HFOs as a biomarker for tailoring will increase the success rate of epilepsy surgery while reducing resection volume. This may reduce neurological deficits and yield a better quality of life. Future technical developments, such as validated automatic online HFO identification, could, together with the attained clinical knowledge, lead to a new objective tailoring approach in epilepsy surgery.

• 出版日期2015-9-23