Funktionelle Organisation expressiver Sprache bei der mesialen Temporallappenepilepsie: fMRT Studie zum Vergleich hippocampaler Aktivierung bei freier Wortproduktion gegenüber Standard-Wortflüssigkeitsaufgaben

语言几乎是人类物种独有的。它在日常生活和社会运作中具有重大意义。言语交流能力对生活质量有着至关重要的影响。因此，语言在临床神经科学中具有很高的兴趣。传统上，语言表达功能与额叶皮质(如Broca区)有关，但最近的研究也指出与颞叶结构(如海马体)的功能相关。内侧颞叶癫痫(MTLE)是影响海马区功能的病变模型。这项fMRI项目旨在研究MTLE患者的词汇流畅性作为一种表达语言功能。单词流畅度通常是通过对给定首字母(音素流畅度)或给定类别(语义流畅度)的单词生成来考察的。然而，自由、不受限制的词汇生成在健康志愿者的fMRI上显示出海马区的激活。这种海马体的激活在精神分裂症患者中减弱，精神分裂症伴随着(除其他病理外)颞叶皮质的结构异常。左半球MTLE患者通常以语言为主，与精神分裂症患者有进一步的共同特征：两者都表现出言语记忆缺陷，而且更有可能出现非典型(双侧或右半球)语言优势。非典型语言优势被认为是神经可塑性导致的功能重组过程的结果。是什么导致了这种重组，目前还不清楚。这项研究旨在增加关于海马体在表达语言中的作用的实质性知识，并旨在更好地表征特定脑损伤患者皮质语言表征的决定因素。语言功能磁共振成像经常应用于癫痫手术的候选患者，以在手术前识别口才皮质。作为一种临床影响，拟议的研究结果将有助于改进目前的功能磁共振语言评估范式。

Language is almost unique to the human species. It is of major relevance in every day life and social functioning. Verbal communication abilities crucially influence quality of life. Therefore, language is of high interest in clinical neuroscience. Expressive language function is classically associated with frontal lobe cortex (e.g. Broca`s area) but recent studies also point towards functional relevance of temporal lobe structures (e.g. the hippocampus). Mesial temporal lobe epilepsy (mTLE) constitutes a lesion model for hippocampal function. This fMRI project aims to study word fluency as an expressive language function in mTLE patients. Word fluency is usually investigated with word generation to a given initial letter (phonemic fluency) or to a given category (semantic fluency). However, free, unrestricted word generation has shown hippocampal activation on fMRI in healthy volunteers. This hippocampal activation was attenuated in schizophrenia, which is accompanied (among other pathology) by structural abnormalities of temporal cortex. Patients with mTLE of the left hemisphere, which is usually language dominant, share further characteristics with schizophrenia patients: Both exhibit verbal memory deficits and have a higher probability of atypical (bilateral or right hemispheric) language dominance. Atypical language dominance is considered a result of functional reorganization processes due to neural plasticity. What leads to such reorganisation is not yet clearly understood. This study intends to add substantial knowledge about the role of the hippocampus in expressive language and aims to better characterize determinants of cortical language representation in patients with specific brain lesions. Language fMRI is frequently applied to patients who are candidates for epilepsy surgery to preoperatively identify eloquent cortex. As a clinical impact, results of the proposed study shall contribute to improve current paradigms for fMRI language assessment.