# Dissecting the Cognitive Roles of Hippocampus and Other Temporal Lobe Structures in Patients Undergoing Epilepsy Surgery

> **NIH NIH R01** · EMORY UNIVERSITY · 2023 · $601,964

## Abstract

Project Summary:
 We have conducted the largest prospective comparative study of laser amygdalohippocampotomy (SLAH), a
minimally invasive procedure ablating the amygdalo-hippocampal complex (AHC) versus selective and standard
open resection (OR) epilepsy surgery (N=425+). We demonstrated that SLAH is superior to OR in 1-year
cognitive outcomes in adults (including episodic verbal memory & perceptual (semantic) recognition or name
retrieval of objects/faces), while achieving comparable seizure control. We will extend our analysis
longitudinally in an unprecedented manner (5-10 year outcome) leveraging this unique cohort of well-studied
patients including neuropsychological (NP), structural and functional neuroimaging and seizure outcomes.
 We have also amassed a large sample of cases involving stereotactic laser ablation [SLA] of non-AHC
structures. The heterogeneity of these SLA cases and the focal nature of the laser ablation surgical zones create
an amazing opportunity for lesion-behavioral analyses. We will expand our neuroimaging analyses to include
rigorous voxel lesion symptom mapping (VLSM) and novel methods of connectivity modeling with diffusion
tensor imaging and resting state fMRI. We will focus on the neural circuitry responsible for declarative memory
and language, while determining the optimal surgical zones to produce the best long-term cognitive and seizure
outcomes. VLSM allows us to determine which temporal lobe regions are critical for specific cognitive
functions, while connectivity analyses will reveal the interconnectedness of these regions in the individual
patient (allowing us to determine the relative risk of decline at the patient level).
 Our preliminary findings indicate that: 1) SLAH patients exhibit unexpected improvement in multiple
cognitive functions, which is unparalleled in their OR counterparts, and 2) SLA procedures sparing the AHC
and broader medial TL regions frequently lead to severe decline in verbal memory/naming, particularly in
cases of focal ablations of the language dominant temporal pole or fusiform gyrus. This suggests that verbal
declarative memory depends upon a broad network extending beyond the AHC, which is a paradigm shift for
surgical planning (i.e., regions thought to be expendable during surgical approach are actually critical to
function). This knowledge is fundamentally important from mechanistic and clinical translational points of
view, and our data and planned analyses provide a unique and feasible way to draw robust conclusions on these
long-standing knowledge gaps. Our data raise pivotal questions about existing declarative memory models and
the mechanism of recovery underlying the superior cognitive outcomes in many SLAH/SLA cases (e.g.,
functional sparing vs. reorganization), which we will address in this renewal by following our patients over
time. Finally, while more epilepsy centers are employing SLA due to its improved cognitive outcomes, ultimate
clinical adoption rests on se...

## Key facts

- **NIH application ID:** 10604348
- **Project number:** 5R01NS088748-09
- **Recipient organization:** EMORY UNIVERSITY
- **Principal Investigator:** DANIEL L DRANE
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $601,964
- **Award type:** 5
- **Project period:** 2014-07-01 → 2025-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10604348

## Citation

> US National Institutes of Health, RePORTER application 10604348, Dissecting the Cognitive Roles of Hippocampus and Other Temporal Lobe Structures in Patients Undergoing Epilepsy Surgery (5R01NS088748-09). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10604348. Licensed CC0.

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