Tadokoro Award 2021 Best basic oral presentation

Abstract #385
Altered resting state networks before and after temporal lobe epilepsy surgery
W. LI1, Y. QIN1, L. ZHANG1, D. AN1, D. ZHOU1
1West China Hospital, Sichuan University, Chengdu, China

Purpose

To explore the resting state networks (RSNs) alterations in patients with unilateral mesial temporal lobe epilepsy (mTLE) before and after successful surgery.

Method

We obtained resting-state functional MRI and high-resolution T1-weighted structural MRI data in 37 refractory mTLE patients who achieved seizure-free for at least 24 months after anterior temporal lobectomy (ATL). They were scanned before surgery and at 24 months after surgery. We also recruited 28 age- and sex-matched healthy controls (HC) who were only scanned once. Independent component analysis (ICA) was adopted to analyze the functional network connectivity (FNC) alterations within and between ten common RSNs before and after surgery. Furthermore, we also studied dynamic functional connectivity (FC) changes between bilateral hippocampi and these RSNs.

Results

Before surgery, decreased FNC was found within visual network 1 (VN1) and basal ganglia network (BGN) when compared with HC, while after surgery, FNC within BGN further decreased and FNC within sensorimotor network (SMN) and dorsal attention network (DAN) increased. Before surgery, decreased FNC was found between BGN-VN1, BGN-visual network 2 (VN2), BGN-auditory network (AN), BGN-SMN, VN1-default mode network (DMN), VN1-left frontoparietal network (lFPN), DAN-AN, DAN-salience network (SN) and increased FNC was found between DMN-DAN, DMN-AN, DMN-lFPN, DMN-right frontoparietal network (rFPN) when compared with HC. After surgery, only increased FNC was found between VN1-VN2, VN1-DMN, VN1-lFPN, VN1-rFPN, VN2-DMN, DAN-AN, DAN-SMN. In addition, before surgery, FC between ipsilateral rostral hippocampus and SMN/VN1/VN2/BGN/DMN/rFPN, between ipsilateral caudal hippocampus and VN1/BGN/DMN/lFPN/rFPN, and between contralateral caudal hippocampus and VN1 significantly decreased when compared with HC, while FC between contralateral rostral hippocampus and SN increased. After surgery, there was a tendency that FNC between contralateral caudal hippocampus and VN1 increased.

Conclusion

MTLE patients showed significant within- and between-RSNs changes before and after successful ATL. These results provide preliminary evidence for postoperative functional remodeling at whole-brain-network level.