皮层脑电图监测在致痫灶切除术中的应用(附96例报告)

目的 探讨皮层脑电图(ECoG)监测在癫痫手术中指导切除致痫灶的价值.,方法 2005年12月至2008年6月期间,96例难治性癫痫患者在经过详细的术前评估后,进行了手术治疗.术中先切除癫痫病灶,再行描记EcoG,监测异常放电是否消失;若癫痫波仍大量存在,则进一步切除病灶周围的致痫灶,直至EcoG监测异常放电消失或明显减少.结果 术后随访12～44个月.根据Engel疗效分级标准进行疗效评价.Engel Ⅰ级45例,Ⅱ级22例,Ⅲ级17例,Ⅳ级12例.手术有效率达到87.50%.结论 术中应用EcoG监测能大大提高致痫灶空间定位的准确性,有效地指导癫痫的手术.     

Language lateralization and cognitive control across the menstrual cycle assessed with a dichotic-listening paradigm

Lateralization has been shown to vary across the menstrual cycle, however, the underlying mechanisms are not fully understood, and results are inconsistent. Additionally, it has been suggested that estradiol enhances cognitive control. By modulating attention in a consonant-vowel dichotic listening test, the current study aims to investigate the effects of cycle-related changes on language lateralization (non-forced condition), as well as the effects of estradiol-modulated cognitive control (forced left condition) on the ear advantage. Fifteen women and fifteen men tested three times on the dichotic listening test, women once in menstrual, follicular, and luteal phase (verified by hormone assays). Whereas the results from the non-forced and forced-right condition remained stable, results from the forced left condition changed across the cycle, where women in the follicular phase compared to both menstrual and luteal phases showed a stronger left ear advantage, i.e. better cognitive control performance. The increase in performance from menstrual to follicular phase correlated negatively with increase in estradiol levels, indicating a shift from a stimulus-driven right ear advantage (indicating a left hemispheric asymmetry for language) when estradiol levels were low toward a cognitively controlled left ear advantage when estradiol levels were high. This finding strongly suggests an active role of estradiol on cognitive control. The study further suggests that the degree of cognitive control demands of a given task is important to consider when investigating lateralization across the menstrual cycle.     

结节性硬化所致婴儿痉挛症发作期脑电局灶或一侧优势现象31例报告

目的：探讨结节性硬化症（TS）所致婴儿痉挛症患者发作期脑电活动局灶改变及其分布优势侧的特征现象,以及与术后疗效的关系。方法：回顾分析了31例TS术前脑电图定位在发作期呈现的局灶、一侧多灶,或双侧均有病灶而以一侧占优势的脑电图现象,并结合术后随访结果对比分析其差异。结果：局灶性放电（单灶）6例,一侧多灶14例,双侧改变以一侧占优势的11例。经统计学处理,局灶与一侧多灶比较差异有显著意义（P〈0．05）．与两侧均有以一侧占优势相比差异有极显著意义（P〈0．01）。结论：TS所致婴儿痉挛症患者间歇期表现为多灶性弥散放电甚至高度失律,但发作期起源灶相对明确,呈现局灶、一侧多灶或者两侧均有以一侧占优势,给外科干预提供有力的依据,并获得良好疗效,尤其对于发作期局灶改变者效果尤好。     

Intralesional recordings and epileptogenic zone in focal polymicrogyria

PURPOSE: Polymicrogyria (PMG) is recognized as an epileptogenic lesion but few data concerning organization of the epileptogenic zone (EZ) are available. METHODS: We analyzed the distribution of the EZ according to Stereo-EEG (SEEG) with intralesional recordings in four patients evaluated for intractable partial epilepsy associated with focal unilateral PMG, involving the posterior temporal region in two, the perisylvian area in one and the temporoparietal junction in the other. All had ictal scalp EEG, high-resolution structural and functional MRI, fluorodeoxyglucose positron emission tomography (FDG-PET), and SEEG. For each patient, several depth electrodes were implanted both within the PMG and in extralesional areas. RESULTS: In three patients, the PMG displayed high-frequency spiking activity. However, interictal and ictal recordings demonstrated a large epileptogenic network, which was more widespread than the PMG, including the mesial temporal structures in two. In another patient, interictal spiking and seizure onset site were located within the hippocampus and outside of the PMG, although it was rapidly involved during seizure spread. Overall, EZ was considered to be larger than the PMG in all patients although hypometabolic areas detected by PET were concordant with EZ. Three patients underwent extensive surgery including the PMG and are seizure free with a follow-up >2 years. DISCUSSION: Although intralesional recordings demonstrated intrinsic epileptogenicity in PMG, our data provide evidence that unilateral focal PMG belongs to a large epileptogenic network extending beyond the MRI lesion. SEEG may be helpful for planning surgery with favorable outcome, providing large resections are feasible, even in apparently focal PMG.     

Prosopagnosia associated with a left occipitotemporal lesion

Acquired prosopagnosia is usually associated with bilateral or right-sided lesions of the occipital or temporal lobes. In rare cases of prosopagnosia after left-sided lesions in left-handed subjects, it is attributed to a reversed hemispheric specialization for face processing. This study examines the face-processing functions of a left-handed prosopagnosic patient with a left-sided lesion affecting the region of the occipital face area and possibly the fusiform face area, to contrast his deficits with those of prosopagnosic patients with right-hemispheric lesions. Similar to those patients, he has a moderately severe reduction in familiarity judgments, is impaired in processing face configuration, and shares with some of those patients a greater failure to process eye than mouth information, indicating an altered pattern of facial saliency. He has a mild reduction in the identification of exemplars of non-face objects. Unlike those patients, he has better residual familiarity on a two-alternative forced-choice task and can processing facial configuration if given more time, indicating a reduction in efficiency rather than a severe limitation. He has more difficulty accessing semantic-biographic information from names. He has trouble with facial feature imagery but not imagery for global face shape. Thus this subject's deficits represent a combination of impaired familiarity and configuration processing (normally right-sided functions in right-handed subjects), and impaired feature processing and access to semantic-biographic information (normally left-sided functions). His prosopagnosia likely reflects partially anomalous rather than reversed lateralization of hemispheric perceptual functions.     

Categorical and coordinate spatial representations within object-location memory

An important aspect of spatial memory is the ability to remember the positions of objects around us. There is evidence that spatial information can be represented in different ways, involving a coordinate representation (fine-grained, metric information) and a categorical representation (above/below, right/left relations). The current study is aimed at investigating possible lateralization effects for categorical and coordinate information when encoding position information alone and when integrating position information and object information in memory. Twenty-five patients who had suffered from a stroke and 36 healthy controls were tested with different tests assessing categorical and coordinate position memory, and categorical and coordinate object-to-position memory. The identity task that was used by (Laeng, 1994) was included as well as a control task for measuring lateralization effect for categorical and coordinate information. Moreover, object-recognition and visuo-spatial perception were assessed. The results showed that processing categorical and coordinate spatial information were impaired by a lesion in the left and right hemisphere, respectively. No lateralization effects were found when spatial information had to be integrated with object information. These results bear on the functional components of object-location memory and their underlying hemispheric basis.     

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目的对上颌前牙区颌骨的骨量及唇侧骨皮质厚度进行测量分析,为正畸治疗植入微种植支抗钉的安全区提供参考依据。方法对2010年9月至2011年6月来大连市口腔医院就诊的25例成人患者行锥形束CT扫描及三维重建,测量距上颌牙槽嵴顶3、6、9、12mm4个水平上颌中切牙、侧切牙、尖牙根间区近远中向、唇腭向的距离以及唇侧骨皮质厚度。结果 (1)在距上颌牙槽嵴顶3、6、9mm水平中切牙根间近远中向距离均最宽,唇侧骨皮质均最薄;(2)在距牙槽嵴顶9mm水平中切牙与侧切牙根间近远中向距离最窄;(3)在4个测量水平侧切牙与尖牙根间唇侧骨皮质均最厚;(4)唇腭向在距牙槽嵴顶9mm及以上水平,中切牙根间骨厚度最薄,中切牙与侧切牙根间骨厚度最厚。25例中仅3例前牙区各牙根长度超过12mm,在距牙槽嵴顶12mm水平能测出根间近远中向距离,均较宽。结论通过对扫描后颌骨影像的分析,明确了前牙区颌骨的骨量及唇侧骨皮质厚度,为植入微种植支抗钉的安全区提供参考依据。     

PET对癫痫致痫区定位的研究进展

正电子发射型计算机断层显像（Positron Emission Computed Tomography ，PET ）是一种探测放射性示踪剂在体内分布及动态变化情况的显像技术，在神经功能影像学检查方法中，PET 目前被认为是癫痫外科术前评估的最佳无创性功能性影像检查方法［1］。 PET 利用不同种类的示踪剂，来探究脑组织葡萄糖代谢、氧代谢、脑血流灌注、神经受体分布、生化和蛋白合成等方面的变化，尤其对于结构影像学检查阴性的癫痫患者有很大的定位诊断价值［2－3］。