# The Role of Network Connectivity in Post-Surgical Seizure Recurrence in Temporal Lobe Epilepsy

> **NIH NIH R01** · VANDERBILT UNIVERSITY MEDICAL CENTER · 2022 · $491,476

## Abstract

PROJECT SUMMARY
Epileptic seizure burden decreases health related quality of life, and is associated with increased morbidity and
mortality. Temporal lobe epilepsy (TLE) is one of the most common forms of epilepsy. For about 60-70% of
these patients, anti-epileptic medication is a successful treatment. In a subset of TLE patients gold standard
clinical assessments identify the hippocampus as the seizure focus (mesial TLE or mTLE), and surgical
resection of this region is a potential treatment for those that are drug refractory. However, even in these
seemingly homogeneous patients with a well-defined seizure focus, seizure freedom rates from surgery range
from approximately 58% to 80% of patients. Our recent work suggests that while the seizure focus may be the
same across this group of patients, the network of seizure propagation may be variable. Using Magnetic
Resonance Imaging (MRI) a presurgical functional and structural model network was characterized in those
patients that were seizure free one year post surgery. Subsequent patients with networks that differed from this
model had unsuccessful outcomes with no improvement or worsening of seizures within the first year after
surgery. In patients with improvement from surgery whose presurgical propagation network was consistent with
the model, variations in a few specific connections were associated with length of time until seizure recurrence
(up to 3 years). This suggests a similar network is responsible for late seizure recurrence in these patients.
Furthermore, by identifying this unique cohort of mTLE patients with similar network properties in whom late
seizures may recur, we hypothesize that it is possible to quantify networks longitudinally as recurrence
develops after surgery. Therefore, the overall goal of this project is to quantify presurgical and post-surgical
MRI network connectivity and their relationship to seizure recurrence after mesial temporal lobe surgery. In
Aim 1 the previously defined presurgical MRI functional and structural connectivity model of mTLE will be
further developed and validated as a biomarker of long term seizure outcome. While the biomarker will include
only presurgical connectivity measures, the development will be informed by the knowledge of how networks
evolve after surgery as determined in Aims 2 and 3. In Aim 2 longitudinal post-surgical MRIs will be used to
quantify functional and structural network evolution for three years after surgery and localize networks
responsible for post-surgical seizures. Finally, Positron Emission Tomography (PET) will be used to localize
the seizure focus via hypometabolism after seizure recurrence to compare with and to inform the networks
identified in Aim 2. This work will ultimately result in the quantification of network evolution in seizure
recurrence, and biomarkers of long term seizure outcome in mTLE.

## Key facts

- **NIH application ID:** 10409633
- **Project number:** 5R01NS110130-04
- **Recipient organization:** VANDERBILT UNIVERSITY MEDICAL CENTER
- **Principal Investigator:** Victoria L Morgan
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $491,476
- **Award type:** 5
- **Project period:** 2018-09-30 → 2024-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10409633

## Citation

> US National Institutes of Health, RePORTER application 10409633, The Role of Network Connectivity in Post-Surgical Seizure Recurrence in Temporal Lobe Epilepsy (5R01NS110130-04). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10409633. Licensed CC0.

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