Sidhu Meneka K, Stretton Jason, Winston Gavin P, McEvoy Andrew W, Symms Mark, Thompson Pamela J, Koepp Matthias J, Duncan John S
1 Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK 2 Epilepsy Society MRI Unit, Chesham Lane, Chalfont St. Peter SL9 0RJ, Buckinghamshire, UK.
1 Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK 2 Epilepsy Society MRI Unit, Chesham Lane, Chalfont St. Peter SL9 0RJ, Buckinghamshire, UK 3 MRC Cognition and Brain Science Unit, Chaucer Road, Cambridge, CB2 7EF, UK.
Brain. 2016 Feb;139(Pt 2):415-30. doi: 10.1093/brain/awv365. Epub 2016 Jan 10.
Anterior temporal lobe resection can control seizures in up to 80% of patients with temporal lobe epilepsy. Memory decrements are the main neurocognitive complication. Preoperative functional reorganization has been described in memory networks, but less is known of postoperative reorganization. We investigated reorganization of memory-encoding networks preoperatively and 3 and 12 months after surgery. We studied 36 patients with unilateral medial temporal lobe epilepsy (19 right) before and 3 and 12 months after anterior temporal lobe resection. Fifteen healthy control subjects were studied at three equivalent time points. All subjects had neuropsychological testing at each of the three time points. A functional magnetic resonance imaging memory-encoding paradigm of words and faces was performed with subsequent out-of-scanner recognition assessments. Changes in activations across the time points in each patient group were compared to changes in the control group in a single flexible factorial analysis. Postoperative change in memory across the time points was correlated with postoperative activations to investigate the efficiency of reorganized networks. Left temporal lobe epilepsy patients showed increased right anterior hippocampal and frontal activation at both 3 and 12 months after surgery relative to preoperatively, for word and face encoding, with a concomitant reduction in left frontal activation 12 months postoperatively. Right anterior hippocampal activation 12 months postoperatively correlated significantly with improved verbal learning in patients with left temporal lobe epilepsy from preoperatively to 12 months postoperatively. Preoperatively, there was significant left posterior hippocampal activation that was sustained 3 months postoperatively at word encoding, and increased at face encoding. For both word and face encoding this was significantly reduced from 3 to 12 months postoperatively. Patients with right temporal lobe epilepsy showed increased left anterior hippocampal activation on word encoding from 3 to 12 months postoperatively compared to preoperatively. On face encoding, left anterior hippocampal activations were present preoperatively and 12 months postoperatively. Left anterior hippocampal and orbitofrontal cortex activations correlated with improvements in both design and verbal learning 12 months postoperatively. On face encoding, there were significantly increased left posterior hippocampal activations that reduced significantly from 3 to 12 months postoperatively. Postoperative changes occur in the memory-encoding network in both left and right temporal lobe epilepsy patients across both verbal and visual domains. Three months after surgery, compensatory posterior hippocampal reorganization that occurs is transient and inefficient. Engagement of the contralateral hippocampus 12 months after surgery represented efficient reorganization in both patient groups, suggesting that the contralateral hippocampus contributes to memory outcome 12 months after surgery.
颞叶前部切除术可控制高达80%的颞叶癫痫患者的癫痫发作。记忆减退是主要的神经认知并发症。术前已在记忆网络中描述了功能重组,但对术后重组的了解较少。我们研究了术前、术后3个月和12个月时记忆编码网络的重组情况。我们对36例单侧内侧颞叶癫痫患者(19例右侧)在颞叶前部切除术前、术后3个月和12个月进行了研究。在三个等效时间点对15名健康对照者进行了研究。所有受试者在三个时间点均进行了神经心理学测试。采用功能磁共振成像的单词和面孔记忆编码范式,并随后进行扫描外识别评估。在单一灵活析因分析中,将每个患者组各时间点激活的变化与对照组的变化进行比较。各时间点记忆的术后变化与术后激活情况相关,以研究重组网络的效率。左侧颞叶癫痫患者在术后3个月和12个月时,相对于术前,右侧前海马和额叶在单词和面孔编码时的激活增加,术后12个月左侧额叶激活减少。左侧颞叶癫痫患者术后12个月时右侧前海马激活与术前至术后12个月时言语学习的改善显著相关。术前,左侧后海马有显著激活,在单词编码时术后3个月持续存在,在面孔编码时增加。对于单词和面孔编码,术后3至12个月时这种激活均显著减少。右侧颞叶癫痫患者在术后3至12个月时,相对于术前,在单词编码时左侧前海马激活增加。在面孔编码时,术前和术后12个月均存在左侧前海马激活。左侧前海马和眶额皮质激活与术后12个月时设计和言语学习的改善相关。在面孔编码时,左侧后海马激活显著增加,术后3至12个月时显著减少。左侧和右侧颞叶癫痫患者在言语和视觉领域的记忆编码网络中均出现术后变化。术后3个月发生的代偿性后海马重组是短暂且低效的。术后12个月对侧海马的参与在两个患者组中均代表有效重组,表明对侧海马在术后12个月对记忆结果有贡献。