Abstracts

Pre-operative Language fMRI as a Predictor of Memory Decline Following Pediatric Epilepsy Surgery

Abstract number : 3.44
Submission category : 5. Neuro Imaging / 5B. Functional Imaging
Year : 2023
Submission ID : 1425
Source : www.aesnet.org
Presentation date : 12/4/2023 12:00:00 AM
Published date :

Authors :
Presenting Author: Lauren Reppert, BA – Children's National Hospital

Manu Krishnamurthy, BS – Children's National Hospital; Maria Chroneos, BS – Children's National Hospital; Venkata Sita Priyanka Illapani, MS – Children's National Hospital; Chima Oluigbo, MD – Children's National Hospital; Sara Inati, Md – NINDS; William Theodore, MD – NINDS; william Gaillard, MD – Children's National Hospital; Madison Berl, PhD – Children's National Hospital; Xiaozhen You, PhD – Children's National Hospital; Leigh Sepeta, PhD – Children's National Hospital

Rationale:
Deficits in memory functioning occur after epilepsy surgery. Language fMRI has been shown to predict memory outcomes in adults (Binder et al. 2008, 2010). In pediatric epilepsy, pre-operative language fMRI may help to evaluate MTL functioning (Sepeta et al. 2016) and could potentially predict memory ability post-operatively. In this study, we aim to determine if the activation resected during a language fMRI task predicts post-operative memory decline.

Methods:
A total of 20 epilepsy patients (ages 5.5-20; Table 1; 13 temporal lobe epilepsy (TLE)) completed memory neuropsychological evaluation (Table 2) both before and after surgery. Post-surgical change in memory functioning was determined via difference scores (post- minus pre-surgical). Pre-operative language fMRI (auditory decision description task) was conducted to determine language dominance. We utilized automatically generated resection masks to compute the overlap amount of activation (magnitude) within the memory network (Neurosynth “episodic memory” mask, including hippocampus, parahippocampus, posterior cingulate, and additional limbic, frontal, and parietal regions.) We then used linear regression to predict post-operative memory functioning from this overlap.

Results:
Pre and post operative memory scores were not different (all p’s > 0.05); however, 6/20 declined at least a standard deviation on one memory measure. 18/20 patients showed activation in the MTL during language fMRI and all 20 patients had signification activation within the memory network during the language fMRI task. A total of 16 patients (80%) had overlap between their surgical resection and memory network activation. This overlap predicted post-operative decline on stories immediate only (R2 =.23, p=0.32). Examining only temporal resections, eleven patients (92%) demonstrated overlap between resection and memory network activation, and eight (40%) patients had overlap between MTL activation and resection. However, the overlap did not predict memory outcomes in temporal resections.

Conclusions:
In the larger surgical sample, eighty percent of patients had memory network resected and this activation predicted memory outcomes (Stories Immediate). Language fMRI may provide an assessment of risk for memory impairment when activation regions within the memory network are removed to pursue seizure freedom. In the future, we will explore more clinical epilepsy variables in this population and use reliable change index to characterize post-operative memory functioning.

Funding:
K23 NINDS NS093152; NINDS Division of Intramural Research

Neuro Imaging