Naming in Frontotemporal Dementia and its neural correlates

The study sought to understand the basis for naming problems in the behavioural form of frontotemporal dementia (bvFTD) through direct comparison with semantic dementia (SD) and examination of neural correlates. The data addresses the question whether naming problems in bvFTD arise secondary to patients' frontal executive disorder or occur independently as additional linguistic deficits.
The data show test scores for 71 patients with bvFTD and 32 with SD on the Graded Naming test (a published challenging test of naming), the Manchester naming test (a less demanding test of picture naming) and a word-picture matching test that uses the same stimuli as the Manchester naming test (10 pictures of animals, 10 of fruits/vegetables, 10 articles of clothing and 10 household objects).

The nature of naming errors is indicated for each test item and are summarised as separate variables. Naming errors are classified in terms of the following types: semantic (e.g. "dog" for rabbit), superordinate category (e.g. "animal" for rabbit), associative (this includes descriptions of an object's function, gestural demonstrations of its use and associated information e.g. "in Australia" for kangaroo), visually related misidentifications, omissions (which includes generic responses that convey insufficient information to convey recognition) and viable alternative responses (e.g. "coat" for jacket).

The data also shows independent (blind) visual ratings of magnitude of atrophy based on coronal magnetic resonance scan images. Different regions of the frontal and temporal lobes are rated in accordance with the scheme defined by Davies et al Neuroradiology, 2009, 51, 491-503.

Background clinical data includes scores on standard executive tests: verbal fluency, Weigls block sorting and Brixton spatial anticipation test.

BvFTD patients, as expected, perform better than the SD group on the language test, but deficits are identified in about half of patients. There are strong inverse correlations between naming scores in both groups and atrophy in temporal lobe structures, particularly the temporal pole and fusiform gyrus, whereas comprehension in SD, measured by word picture matching, correlates more strongly with posterior than anterior temporal lobe atrophy. Error analysis shows a significant relationship in both groups between associative-type responses and temporal pole atrophy, whereas 'don't know' responses, suggestive of a loss of conceptual knowledge, correlates with more posterior temporal regions. There is some correlation in bvFTD between naming and executive performance but not frontal lobe atrophy.

The data support the view that naming problems in bvFTD can arise independently of 'frontal' executive deficits and highlight clinical overlap with bvFTD. The findings have implications for the hub-and-spoke model of semantic memory and argue against the notion of the temporal pole as a semantic hub.

本研究旨在通过直接对比语义痴呆（SD）并考察神经关联，探讨命名问题在额颞痴呆行为型（bvFTD）中的命名基础。数据集旨在解答bvFTD中的命名问题是否由患者的额叶执行功能障碍所继发，或作为独立的语言缺陷而独立出现。数据包括71名bvFTD患者和32名SD患者在分级命名测试（一种已发表的具有挑战性的命名测试）、曼彻斯特命名测试（一种对图片命名要求较低的测试）以及使用与曼彻斯特命名测试相同刺激的词汇-图片匹配测试（包括10张动物图片、10张水果/蔬菜图片、10件衣物和10件家居用品）中的测试分数。对于每个测试项目，命名错误的具体性质被指示并作为单独的变量进行总结。命名错误根据以下类型进行分类：语义错误（例如，将“狗”称为“兔子”），上位类别错误（例如，将“兔子”称为“动物”），联想错误（包括对物体功能的描述、使用时的手势演示及其相关信息，例如“在澳大利亚”用于“袋鼠”），视觉相关错误识别、遗漏（包括不足以传达识别的通用回答）和可行的替代回答（例如，“外套”用于“夹克”）。数据还显示了基于冠状磁共振扫描图像的独立（盲法）萎缩程度视觉评估。根据Davies等人在《神经放射学》（2009年，第51卷，第491-503页）中定义的方案，对额叶和颞叶的不同区域进行评分。背景临床数据包括标准执行测试的得分：语言流畅性、Weigl积木分类和Brixton空间预期测试。与预期一致，bvFTD患者在语言测试中的表现优于SD组，但约有一半的患者存在缺陷。两组患者在命名分数与颞叶结构（尤其是颞极和梭状回）的萎缩之间存在强烈的负相关，而SD组中的理解能力（通过词汇-图片匹配测量）与前颞叶萎缩的相关性不如后颞叶萎缩强。错误分析显示，两组中联想类型回答与颞极萎缩之间存在显著相关性，而“不知道”的回答，暗示概念知识的丧失，与更后颞叶区域的相关性更强。在bvFTD中，命名与执行表现之间存在一些相关性，但并非与额叶萎缩相关。这些数据支持了命名问题在bvFTD中可以独立于“额叶”执行缺陷出现的观点，并突出了与bvFTD的临床重叠。这些发现对语义记忆的枢纽-辐条模型有重要意义，并反对将颞极视为语义枢纽的观点。