# Seizure localization for epilepsy surgery using high frequency electrophysiological markers

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA-IRVINE · 2022 · $342,434

## Abstract

PROJECT SUMMARY/ABSTRACT
In the most severe cases of epilepsy, where seizures persist despite multiple trials of anti-seizure medications,
patients may benefit from surgical removal of seizure-generating brain tissue. Prior to surgery, electrodes are
often implanted directly into or onto the patient’s brain and are used to continuously record electrical brain
activity over days. This is done to capture seizure activity and determine its point of origin, i.e. the seizure
onset zone. If the seizure onset zone is identified, clinicians then use this information, in combination with the
results of brain imaging and other testing, to guide removal of the corresponding brain tissue. While epilepsy
surgery may lead to seizure freedom, 70-90% of surgery patients remain on anti-seizure medications and
roughly 50% of patients continue to have seizures. The long-term goal of this work is to improve the outcomes
of patients undergoing epilepsy surgery by developing more accurate methods to localize seizure-generating
tissue. High frequency oscillations (HFOs) have garnered considerable excitement for their potential to identify
and localize epileptogenic brain tissue. HFOs are short bursts of high-frequency electrical activity that occur in
the brains of patients with epilepsy. They occur more frequently in the epileptogenic zone (EZ, the hypothetical
area that must be excised to attain post-operative seizure freedom), and surgically removing HFO-generating
brain tissue increases the likelihood of seizure freedom. While ongoing clinical trials are attempting to assess
their prospective value for epilepsy surgery planning, there are multiple barriers to their widespread use. While
group-level results are robust, HFO analysis is not yet predictive for single subjects. Recordings lack the
sensitivity to reliably measure HFOs in every patient, and the occurrence of non-epileptic HFOs confounds the
results. Therefore, HFOs are poised to revolutionize epilepsy surgery, but there is a critical need to optimize
their measurement and maximize single-subject accuracy. The overall objective of this proposal is to improve
EZ localization accuracy through systematic determination of the optimal HFO measurement methodology,
coupled with novel, robust methods for HFO analysis. The rationale is that developing these novel methods
with improved measurement techniques will increase the accuracy and robustness of HFOs as a biomarker of
the seizure onset zone, thus improving the surgical management of epilepsy. To attain our objective, we will
pursue three specific aims: (1) Demonstrate that electrode size is a crucial factor in HFO measurement. (2)
Develop an automated method for patient-specific localization of the EZ based on HFOs. (3) Evaluate the
effects of electrode size and HFO analysis method on EZ localization. The proposed research is significant
because it will provide specific recommendations for the measurement and analysis of HFOs, enabling
accurate, detailed loca...

## Key facts

- **NIH application ID:** 10368114
- **Project number:** 5R01NS116273-02
- **Recipient organization:** UNIVERSITY OF CALIFORNIA-IRVINE
- **Principal Investigator:** Beth Ann Lopour
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $342,434
- **Award type:** 5
- **Project period:** 2021-03-15 → 2026-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10368114

## Citation

> US National Institutes of Health, RePORTER application 10368114, Seizure localization for epilepsy surgery using high frequency electrophysiological markers (5R01NS116273-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10368114. Licensed CC0.

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