Structural and functional effects of circumscribed temporal lobe resections

颞叶癫痫是最常见的难治性局灶性癫痫。虽然癫痫控制有效，但切除颞叶的海马（HC）使患者面临术后言语记忆下降的风险。对于海马外癫痫发作的TLE，“保留海马”手术旨在保留最大量的功能组织，降低神经心理恶化的风险。然而，我们最近证实了保留HC切除术后TLE患者的VM下降。此外，观察到显著的术后同侧海马体积损失，这与VM性能降低相关。由于HC是颞叶（TL）内分布式记忆网络的一部分，因此可以想象，即使是有限的TL切除也可能破坏该网络，最终通过传入脑区域的输入丢失导致HC萎缩。为了评价TL病灶切除术对局部和远距离脑结构和功能的影响，本研究将研究对象分为前TL切除术组（N=30）、HC-s病灶切除术组（N=20）和健康对照组（N=30）。结果将与神经心理学数据（对抗命名，言语流畅性，言语自由回忆，短期记忆）相关。此外，将使用线性模型来关联HC-s手术对通过TL内局部和大尺度扩散张量成像所欣赏的皮质连接的影响。此外，我们还将建立基于结构和功能连接指标的术后认知结果预测模型。术后记忆减退是TLE手术的严重并发症，严重影响术后生活质量。更好地了解手术对TL结构和功能网络的影响将有助于预测术后神经心理学表现。对于VM丢失的高风险患者，这将最终有助于术前咨询和临床决策

Temporal lobe epilepsy (TLE) is the most common drug-refractory focal epilepsy. While effective in seizure control, resection of the hippocampus (HC) of the dominant temporal lobe exposes patients to a risk of postoperative verbal memory decline. In TLE with extra-hippocampal seizure onset, “hippocampus-sparing” surgery aims at preserving the largest amount of functional tissue, reducing risks of neuropsychological deterioration. Nevertheless, we recently demonstrated VM decline in TLE patients after HC-sparing resections. Furthermore, significant postoperative ipsilateral hippocampal volume loss was observed, which correlated with reduced VM performance. Since the HC is part of a distributed memory network within the temporal lobe (TL), it is conceivable that even limited TL resection could disrupt this network, ultimately leading to HC atrophy through loss of input from afferent brain regions. To evaluate effects of TL lesionectomy on brain structure and function locally and at distance, the proposed project will target cohorts of patients with anterior TL resection (N=30), HC-s lesionectomy (N=20) and healthy controls (N=30).We will perform hippocampus subfield volumetry on pre- and post-operative MRI to evaluate subfield-specific postoperative alterations. Results will be correlated with neuropsychological data (confrontation naming, verbal fluency, verbal free recall, short-term memory). Additionally, linear models will be used to relate the impact of HC-s surgery on cortical connectivity appreciated through diffusion-tensor imaging locally within the TL and at large-scale. Moreover, we will build predictive models of post-operative cognitive outcome based on structural and functional connectivity metrics.Postoperative memory decline is a serious complication in TLE surgery, with strong impact on postoperative quality of life. Better understanding of the effects of surgery on TL structural and functional networks will allow for the prediction of postoperative neuropsychological performance. In patients at high-risk for VM loss, this will ultimately aid in preoperative counseling and clinical decision making