抽动-秽语综合征内隐和外显记忆的研究

目的：研究抽动－秽语综合征的外显记忆与内隐记忆特点。方法：采用配对病例对照研究设计，选取确诊的抽动－秽语综合征患者及匹配健康对照各26例，用加工、分离程度的方法测定其意识性提取及自动提取在丙认测验中的贡献。结果：与健康对照组相比，抽动－秽语综合征患者的外显记忆显著低于对照组，内隐记忆差异无显著性。按年龄分层比较后，病例组7－8岁年龄段的外显记忆与同年龄对照组相比差异有显著性，其他年龄段差异无显著性。结论：抽动－秽语综合征患者的外显记忆受损而内隐记忆正常，说明外显记忆与内隐记忆属于两个独立的记忆系数。     

Memory lateralization in medial temporal lobe epilepsy assessed by functional MRI

PURPOSE: To determine the utility of functional magnetic resonance imaging (fMRI) in preoperative lateralization of memory function in patients with medial temporal lobe epilepsy (MTLE). METHODS: Nine patients with MTLE underwent standard preoperative assessment including video-EEG and intracarotid amytal testing (IAT). fMRI was performed while subjects encoded four types of stimuli (patterns, faces, scenes, and words). Activation maps were created for each subject representing areas more active for novel than for repeated stimuli. Regions of interest were drawn around the MTL in individual subjects, suprathreshold voxels were counted, and an asymmetry index was calculated. RESULTS: In eight of nine subjects, lateralization of memory encoding by fMRI was concordant with that obtained from the IAT. Group-level analysis demonstrated greater activation in the MTL contralateral to the seizure focus such that in the left MTLE group, verbal encoding engaged the right MTL, whereas in the right MTLE group, nonverbal encoding engaged the left MTL. CONCLUSIONS: fMRI is a valid tool for assessing of memory lateralization in patients with MTLE and may therefore allow noninvasive preoperative evaluation of memory lateralization. FMRI revealed that memory encoding may be reorganized to the contralateral MTL in patients with MTLE.     

Verbal semantic memory in temporal lobe epilepsy

OBJECTIVES: Temporal lobe epilepsy (TLE) may determine memory difficulties not explained by episodic memory impairment. The present study was aimed to verify the presence of specific semantic memory dysfunctions in TLE and to explore their relations to epilepsy variables. SUBJECTS AND METHODS: Forty-seven patients with lateralized temporal (n = 26) or extra-temporal lobe epilepsy (n = 21) and 23 healthy subjects were compared. Picture Naming and Pointing to a Picture were used to explore expressive and receptive vocabulary and the Semantic Questionnaire evaluated semantic judgment of verbally presented items. The Selective Reminding Procedure for word list learning and Story Recall were used to assess episodic memory. Spontaneous speech and the Token Test controlled for language disturbances, and Raven's Coloured Progressive Matrices were used to evaluate abstract reasoning ability. RESULTS: Multivariate analysis of variance of test scores showed significant impairment of semantic memory in patients with left TLE compared to healthy controls, whereas episodic memory was impaired in left temporal and extra-temporal epilepsy (as measured by word learning) and all epilepsy groups (as measured by Story Recall). In the TLE groups, naming abilities were more compromised than single-word comprehension and semantic judgment - which were not significantly affected. No deficits in language abilities or in abstract reasoning were found in any patient group. Factor analysis of memory tests scores in the patients produced two factors, one semantic and the other episodic. Regression analysis revealed that the semantic factor was related to abstract reasoning, left hemisphere lateralization of seizures, and age of seizure onset; while the episodic factor was related to age. CONCLUSIONS: Left TLE may determine significant verbal semantic memory compromise, maybe due to impaired access to the semantic-lexical storage. In non-aphasic epilepsy patients, comparison of performance on semantic and episodic memory tests may be useful for assessing the nature of memory failures, and may complement clinical and neurophysiological means for defining the epileptic center.     

颞叶癫痫对前瞻性记忆的影响

目的 探讨颞叶癫痫对基于事件的前瞻性记忆(event-based prospective memory,EBPM)和基于时间的前瞻性记忆(time-based prospective memory,TBPM)的影响,验证颞叶参与前瞻性记忆的神经机制假说.方法 采用McDaniel等建立的前瞻性记忆神经心理学试验方法,测试62例颞叶癫痫患者(33例服用抗癫痫药物和29例未服用药物,颞叶癫痫组)和年龄、教育程度相匹配的30名健康者(健康对照组)的EBPM和TBPM.结果 颞叶癫痫组简易精神状态检查(MMSE)、数字广度测试(DS)、词汇流畅性测试(VFT)的成绩均低于健康对照组,且MMSE、VFT两组间差异有统计学意义.与健康对照组[ EBPM测试(6.83±1.34)分,TBPM测试(5.00±1.70)分]相比,颢叶癫痫组的EBPM测试[(3.95±2.77)分]和TBPM测试[(3.08±2.42)分]的成绩差异均有统计学意义(t=6.72、4.39,均P＜0.01),且TBPM测试得分均低于EBPM.其中服药和未服药两组间EBPM测试成绩[(3.82±2 70)、(4.10±2.90)分]差异无统计学意义(t=-0.40,P ＞0.05),两组间TBPM测试成绩[(2.55±2.20)、(3.69±2.55)分]差异亦无统计学意义(t=-1.90,P＞0.05).结论 颞叶癫痫患者存在前瞻性记忆损害,提示颞叶参与前瞻性记忆的神经机制过程;与EBPM相比,TBPM损害更明显,提示TBPM需要更多的自我发动过程.     

Material-specific lateralization of working memory in the medial temporal lobe

Mnemonic deficits in patients with medial temporal lobe (MTL) damage arising from temporal lobe epilepsy (TLE) are traditionally constrained to long-term episodic memory, sparing short-term and working memory (WM). This view of WM as being independent of MTL structures has recently been challenged by a small number of patient and neuroimaging studies, which have focused primarily on visual and visuospatial WM. In the present study we investigated material-specific lateralization of WM in 96 patients with unilateral damage to MTL stemming from TLE (56 left) and 30 control subjects using a pair of matched verbal and visuospatial supraspan tasks. Patients with unilateral TLE were impaired on both verbal and visuospatial WM tasks irrespective of the affected hemisphere. Patients with unilateral right TLE showed an additional deficit for visuospatial WM capacity when contrasted with patients with left TLE, whereas patients with unilateral left TLE showed increased intrusion errors on the verbal task when compared to patients with right TLE. These findings suggest a material-specific lateralization of WM in the MTL.     

Involvement of the medial temporal lobe in priming for new associations

This study was addressed to the question of whether the medial temporal lobe (MTL) plays a critical role in implicit memory for new associations. Priming for new associations was examined in two different tasks in 18 patients with focal lesions all involving the MTL. In Experiment 1, following a study phase for pairs of unrelated words, subjects performed a perceptual identification task on old, recombined, and new pairs of words presented at brief exposure durations. In contrast to control subjects, and despite a normal level of item priming, the patients failed to show superior identification of the old pairs relative to the recombined pairs, the measure of associative priming. In Experiment 2, subjects engaged in speeded naming of the print color for previously studied words presented in the original color or in a different old color, and for unstudied words. Again, in contrast to control subjects and despite a normal level of item facilitation on color naming reaction time (RT), the patients failed to show priming for recently experienced new associations between words and colors. Explicit recognition memory by the patients was abnormal in both experiments. This study records an absence of priming for new associations, in two different tasks in which the nature of the stimuli was considerably different, in a large group of patients with lesions in the MTL. Although some previous research has reported significant associative priming in other tasks for patients with MTL lesions, the present results suggest that this region is critical for forming new associations of the types assessed here.     

Face memory in MRI-positive and MRI-negative temporal lobe epilepsy

PURPOSE: Effects of MRI-positive (MRI(+)) as compared to MRI-negative (MRI(-)) temporal lobe epilepsy (TLE) on face memory are not yet known. METHODS: We studied 24 MRI(-) (11 right/13 left) and 20 MRI(+) (13 right/7 left) TLE patients, 12 generalized epilepsy patients, and 12 healthy subjects undergoing diagnostic workup with 24-72-h Video-EEG-monitoring. Twenty faces were shown, and had to be recognized from 40 faces immediately and after a 24-h delay. RESULTS: MRI(+) and MRI(-) right TLE (RTLE) patients showed deficits in face recognition compared to controls or generalized epilepsy, consistent with right temporal lobe dominance for face recognition. MRI(+) RTLE patients had deficits in both immediate and delayed recognition, while MRI(-) RTLE patients showed delayed recognition deficits only. The RTLE groups showed comparable delayed recognition deficits. Separate analyses in which the MRI(+) group included patients with hippocampal sclerosis only, did not alter results. Furthermore, MRI(-) RTLE had a worse delayed recognition than MRI(-) left TLE (LTLE). On the other hand, MRI(+) RTLE did not differ from MRI(+) LTLE in delayed recognition. Combining MRI(-) and MRI(+) TLE groups, we found differences between RTLE and LTLE in delayed, but not immediate face recognition. CONCLUSIONS: Our results suggest that a delayed recognition condition might be superior to immediate recognition tests in detecting face memory deficits in MRI(-) RTLE patients. This might explain why former studies in preoperative patients did not observe an immediate face recognition dominance of the right temporal lobe when combining MRI(-) and MRI(+) TLE patients. Our data further point to an important role of the right mesial temporal region in face recognition in TLE.     

头颅MRI海马像异常与难治性内侧颞叶癫(癎)患者近期记忆损害

目的 探讨难治性内侧颞叶癫(癎)(MTLE)患者影像学异常及发作间期放电(IEDs)优势侧对近期记忆损害的影响.方法 纳入2006年9月至2007年4月我院癫(癎)中心门诊就诊的难治性MTLE患者50例,根据MRI海马像检查将其分为左侧MRI(+)组、右侧MRI(+)组、MRI(-)组及双侧MRI(+)组.综合多次IEDs结果进行评定,若一侧独立IEDs≥75%,则判为IEDs优势侧.采用临床记忆量表(CMS)对患者进行记忆评定.结果 年龄、性别、职业、文化程度、是否来自农村、病程、发作情况、药物治疗各因素在4组间的分布相匹配.各组记忆商(MQ)及分量表的年龄量表分比CMS正常均数差(P＜0.05).右侧MR[(+)组无意义图形再认得分(9.42±7.46)相对于左侧MRI(+)组(16.26±4.43)和MRI(-)组(18.26±5.49)低(F=4.281,P＜0.05).MRI(-)者中左侧IEDs、右侧IEDs、双侧IEDs 3组间MQ及各分量表的年龄量表分值均无统计学意义.结论 右侧MRI(+)MTLE患者在空间图形记忆方面的损害更加显著,无意义图形再认对于非语言记忆的评价有较高的特异性.     

Remote memory in temporal lobe epilepsy

PURPOSE: The present study aims at characterizing remote memory in patients with temporal lobe epilepsy (TLE); it also considers the impact of its most important variables (lateralization of the lesion, duration of epilepsy, age at onset, and seizure frequency) on remote memory. METHODS: We examined the performance of 38 patients with unilateral TLE (19 right TLE and 19 left TLE) and 35 healthy subjects on six remote memory tasks. Memory for personal events was assessed by using the Autobiographical Memory Interview and the Modified Crovitz Test. Memory for public events was evaluated by means of photographs of famous faces and famous scenes, questions about famous events, and the Dead/Alive Test. RESULTS: Both right-TLE and left-TLE groups had impaired memory for autobiographic episodes and public events relative to normal subjects. In contrast, personal semantic memory was preserved. In addition, an effect of laterality was recorded, with right-TLE patients obtaining significantly better scores than left-TLE patients on every test. Duration of epilepsy, age at onset, and seizure frequency did not influence performance on remote memory measures. CONCLUSIONS: The comprehensive neuropsychological study of 38 TLE patients showed that this neurologic condition affects remote memory systems differently. We discuss the different factors that could account for this pattern of performance on the bases of both functional brain organization and memory theories.     

Functional and structural changes in the memory network associated with left temporal lobe epilepsy

Understanding functional plasticity in memory networks associated with temporal lobe epilepsy (TLE) is central to predicting memory decline following surgery. However, the extent of functional reorganization within memory networks remains unclear. In this preliminary study, we used novel analysis methods assessing network‐level changes across the brain during memory task performance in patients with TLE to test the hypothesis that hippocampal functions may not readily shift between hemispheres, but instead may show altered intra‐hemispheric organization with unilateral damage. In addition, we wished to relate functional differences to structural changes along specific fibre pathways associated with memory function. Nine pre‐operative patients with intractable left TLE and 10 healthy controls underwent functional MRI during complex scene encoding. Diffusion tensor imaging was additionally performed in the same patients. In our study, we found no evidence of inter‐hemispheric shifts in memory‐related activity in TLE using standard general linear model analysis. However, tensor independent component analysis revealed significant reductions in functional connectivity between bilateral MTL, occipital and left orbitofrontal regions among others in left TLE. This altered orbitofrontal activity was directly related to measures of fornix tract coherence in patients (P < 0.05). Our results suggest that specific fibre pathways, potentially affected by MTL neurodegeneration, may play a central role in functional plasticity in TLE and highlight the importance of network‐based analysis approaches. Relative to standard model‐based methods, novel objective functional connectivity analyses may offer improved sensitivity to subtle changes in the distribution of memory functions relevant for surgical planning in TLE. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.     

Quality of life and memory performance in patients with temporal lobe epilepsy

OBJECTIVE: To explore the contribution of memory performance to quality of life (QOL) in patients with left or right temporal lobe epilepsy (TLE). SUBJECTS AND METHODS: Sixty-five patients with left or right TLE compiled the QOL in Epilepsy-89 Inventory (QOLIE-89), the State-Trait Anxiety Inventory (STAI) and the Hopelessness Scale (BDI) for self-evaluation of QOL and mood. Memory was assessed by tests of verbal and non-verbal memory and the Questionnaire of Memory Efficiency (QME). A neuropsychological battery was also administered to assess general intelligence, attention, visual perception, language, set shifting, word fluency and conceptual-motor tracking. RESULTS: On factor analysis, the neuropsychological battery and mood scales consisted of six factors (Memory, Mental Speed, Mood, Praxis, Sorting and Perception), while the QOLIE-89 consisted of five factors (Psychosocial Satisfaction, Epilepsy-Related Effects, Role, Physical Performance, Cognition). On regression analysis, overall QOLIE-89 score was predicted by the factor Mood and QME score. The QOLIE-89 factor Cognition was predicted by QME score and the Memory, Mental Speed, Perception and Praxis factors of the neuropsychological battery. CONCLUSION: In TLE patients self-reported memory, as assessed by QME, is an important predictor of QOL, and also correlates with performance on memory tests. This suggests that memory improvement by specific training may help to improve QOL in these patients.     

The overall pathological status of the left hippocampus determines preoperative verbal memory performance in left mesial temporal lobe epilepsy

Studies on hippocampal cell loss in epilepsy have produced diverging evidence as to which subfields are specifically related to memory. This may be due to rather small and often heterogeneous samples, or to different memory measures. Therefore, the current study examined hippocampal cell densities and memory in a large sample of patients with solely mesial temporal lobe epilepsy (mTLE), employing measures with proven sensitivity to mesiotemporal pathology. In 104 patients who had undergone epilepsy surgery for mTLE, we evaluated the role of segmental hippocampal cell loss and its underlying factor structure with regard to presurgical verbal and figural memory while controlling for side‐of‐surgery and hemispheric dominance. First of all, patients showed material‐specific memory impairment concordant with the lateralization of epilepsy. Factor analysis of segmental cell loss revealed a single factor reflecting the overall integrity of the hippocampus. The overall pathological status of the left hippocampus correlated with verbal memory parameters (r = 0.33–0.34, P < 0.05), especially when controlling for atypical hemispheric dominance (r = 0.50–0.57, P < 0.01), and explained up to 33% of the observed variance. Further analyses revealed no superior role of a single subfield or cell loss pattern for memory performance. No systematic relations between neuronal cell densities of the right hippocampus and memory function were found, nor did left or right hippocampal pathology explain figural memory parameters. The results suggest that the overall pathological status of the left hippocampus – rather than a specific subfield pathology – is predictive for verbal memory in mTLE. The finding that figural memory parameters, although sensitive to right mTLE, were not related to neuronal cell densities of the right hippocampus, puts the left/right hippocampus verbal/nonverbal memory dichotomy into perspective. © 2014 Wiley Periodicals, Inc.     

Medial temporal lobe contributions to cued retrieval of items and contexts

Several models have proposed that different regions of the medial temporal lobes contribute to different aspects of episodic memory. For instance, according to one view, the perirhinal cortex represents specific items, parahippocampal cortex represents information regarding the context in which these items were encountered, and the hippocampus represents item–context bindings. Here, we used event-related functional magnetic resonance imaging (fMRI) to test a specific prediction of this model—namely, that successful retrieval of items from context cues will elicit perirhinal recruitment and that successful retrieval of contexts from item cues will elicit parahippocampal cortex recruitment. Retrieval of the bound representation in either case was expected to elicit hippocampal engagement. To test these predictions, we had participants study several item–context pairs (i.e., pictures of objects and scenes, respectively), and then had them attempt to recall items from associated context cues and contexts from associated item cues during a scanned retrieval session. Results based on both univariate and multivariate analyses confirmed a role for hippocampus in content-general relational memory retrieval, and a role for parahippocampal cortex in successful retrieval of contexts from item cues. However, we also found that activity differences in perirhinal cortex were correlated with successful cued recall for both items and contexts. These findings provide partial support for the above predictions and are discussed with respect to several models of medial temporal lobe function.     

丙泊酚Wada试验与功能磁共振在颞叶癫痫词汇记忆功能偏侧化评估中的应用

目的 比较丙泊酚Wada试验与功能磁共振(fMRI)在左颞叶癫痫患者术前记忆功能偏侧化预测中的一致性和敏感性. 方法 对广州军区广州总医院自2009年10月至2011年10月收治的8例左前颞叶切除的癫痫患者术前进行丙泊酚Wada试验和fMRI记忆功能偏侧化评估,结合韦氏记忆测验结果,比较两者记忆功能偏侧化评估的一致性与预测记忆变化的敏感性. 结果 fMRI词汇记忆半球、内侧颞叶功能偏侧化与Wada试验功能偏侧化判定的一致率分别为57.0％和71.4％,术后记忆商数、词汇匹配以及智力改变与fMRI词汇记忆内侧颞叶功能偏侧化指数呈显著相关(r=-0.314,P=0.037;r=-0.387,P=.013;r=0.116,P=0.020),与Wada试验功能偏侧化指数无相关性(r=-0.442,P=.077;r=-0.241,P=0.237;r=-0.070,P=0.107). 结论 丙泊酚Wada试验和fMRI记忆功能偏侧化评估一致性因感兴趣区选择方法不同而不同.相对于Wada试验,fMRI记忆功能偏侧化指数在预测患者术后词汇记忆下降的过程中敏感性更高.     

Postoperative recovery of hippocampal contralateral diffusivity in medial temporal lobe epilepsy

PURPOSE: To search for a recovery after surgery of mean diffusivity (MD) values in the contralateral nonsclerotic hippocampus of patients with medial temporal lobe epilepsy (MTLE) and hippocampal sclerosis (HS). METHODS: Twenty-four MTLE patients (12 right-sided and 12 left-sided MTLE) and 36 healthy volunteers were investigated using diffusion tensor imaging. A region-of-interest approach was used to measure pre- and postoperative interictal hippocampal MD values in patients. RESULTS: Diffusion abnormalities in contralateral nonsclerotic hippocampus recovered after surgery (p<0.0001). A subgroup of 14 patients exhibited a clear increase in MD values whereas the remaining 10 patients were stable. No significant difference was found between the two subgroups for each of the electroclinical data studied including early postoperative outcome, all patients being either seizure free or with rare persistent auras. CONCLUSIONS: This finding suggests that diffusion abnormalities in contralateral hippocampus may represent a functional mechanism linked to the active epileptic process.     

Lateralizing value of memory tests in drug-resistant temporal lobe epilepsy

Our aim was to test the lateralizing value of a neuropsychological battery including several memory tests on a large sample of consecutive patients with drug-resistant temporal lobe epilepsy (TLE) evaluated for epilepsy surgery. We studied 73 right-handed patients (56% males, mean age 35.3 +/- 11.2 years, 49% left TLE) aged 16 years or older with normal IQ who underwent a preoperative neuropsychological assessment including several memory tests and were seizure-free after at least 1 year of follow-up. Forty-seven had TLE due to hippocampal sclerosis, whilst 26 had TLE secondary to tumors or other lesions. Receiver Operating Characteristic (ROC) analysis and discriminant function analysis were used to evaluate the lateralization value of selected tests and of the battery as a whole, respectively. In patients with TLE secondary to tumors or other lesions, no test showed significant lateralizing value. In patients with TLE due to hippocampal sclerosis, the immediate (P < 0.01) and delayed (P < 0.001) Rey Auditory Verbal Learning Test (RAVLT) displayed substantial discriminatory ability. The battery as a whole correctly classified 82% of patients with respect to side of epileptogenesis. Our findings suggest that a non-invasive, relatively short and unexpensive neuropsychological battery based on memory tests may profitably complement other well-established diagnostic procedures such as video-EEG or magnetic resonance imaging (MRI), at least in patients with drug-resistant TLE due to hippocampal sclerosis.     

y-氨基丁酸受体与颞叶癫痫的研究进展

颞叶癫痫（TemporalLobeEpilepsy,TLE）是最常见的一种癫痫综合征,根据发病位置分为内、外侧颞叶癫痫,其中内侧颞叶癫痫（MesialTLE,MTLE）以海马硬化为主要病理改变,与海马局部中间神经元功能障碍、环路重构,胶质增生以及大脑兴奋抑制失衡有关。TLE多数呈耐药性,严重影响患者的生活质量,对TLE的研究一直是学术界的热点。近年来发现7-氨基丁酸（GABA）受体改变与TLE关系密切。GABA作为哺乳动物脑内最主要的抑制性神经递质,在大脑广泛分布。现对GABA受体与TLE相关性的研究进展作一综述。     

颞叶癫痫大鼠病灶脑电的混沌特性

目的以相关维数(Dc)作为主要指标研究Wistar大鼠癫痫病灶脑电生理活动的混沌特性。方法15只健康Wistar雌性大鼠,体质量为210～260g,选择其中10只制备慢性癫痫模型作为实验组;另5只健康Wistar雌性大鼠为正常对照组。采用动态脑电图仪测量大鼠的脑电波波形,量化记录正常对照组和癫痫实验组大鼠的脑电生理活动,以G-P法计算不同状态下的相关维数,并用相关维数来表示相对应的大脑功能。对组间及组内两侧相关维数的比较进行统计学处理。结果对照组大鼠的相关维数值为6～8,而实验组大鼠在病灶处的相关维数值为2～6,组间相关维数分布范围差异具有显著性意义(P<0.01);对照组与实验组大鼠左右两侧相关维数的比较,则差异无显著性意义(均P>0.05)。结论正常大鼠与癫痫大鼠的大脑功能状态有所不同,正常大鼠的脑电生理活动复杂程度高于癫痫大鼠。     

小儿顽固性颞叶癫痫的病理特点研究

目的 研究小儿顽固性颞叶癫痫的临床病理学表现.方法 80例小儿顽固性颞叶癫痫患者行标准前颞叶切除术,切除组织送病理学检查.术后随访1-5年,根据Engel分级评估手术效果.结果 切除组织病理学表现以单纯海马硬化(26例)、良性肿瘤(20例)、局灶性皮层发育不良(10例)和海马硬化合并颞叶其他病变(9例)四大类型为主.癫痫发作控制结果提示EngelⅠ级58例,Ⅱ级11例,Ⅲ级6例,Ⅳ级5例.结论 小儿顽固性颞叶癫痫病理表现多样,以海马硬化、良性肿瘤和局灶性皮层发育不良最常见;颞叶切除疗效肯定;病理类型与手术效果之间的关系仍待更多研究.