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"semantic dementia"

David Playfoot, Jac Billington, Jeremy J Tree
This paper describes longitudinal testing of two Semantic Dementia (SD) cases. It is common for patients with SD to present with deficits in reading aloud irregular words (i.e. surface dyslexia), and in lexical decision. Theorists from the connectionist tradition (e.g. Woollams, et al., 2007) argue that in SD cases with concurrent surface dyslexia, the deterioration of irregular word reading and recognition performance is related to the extent of the deterioration of the semantic system. The Dual Route Cascaded model (DRC; Coltheart et al...
February 9, 2018: Neuropsychologia
Mariko Sakai, Hiroaki Kazui, Kazue Shigenobu, Kenjiro Komori, Manabu Ikeda, Takashi Nishikawa
Objective: To investigate the gustatory function in patients with semantic dementia (SD). Methods: Detection and recognition thresholds of the 4 basic tastes (sweet, salty, sour, and bitter), taste discrimination, and taste identification were evaluated in 18 patients with SD, 18 patients with Alzheimer disease (AD), and 22 healthy controls. Results: Total detection and recognition threshold values were significantly higher in the SD and AD groups than in the control group...
September 2017: Dementia and Geriatric Cognitive Disorders Extra
Yumi Takano, Keiko Kunitoki, Yasuko Tatewaki, Tatsushi Mutoh, Tomoko Totsune, Hideo Shimomura, Manabu Nakagawa, Hiroyuki Arai, Yasuyuki Taki
BACKGROUND Semantic dementia (SD) is a type of primary progressive aphasia with prominent language dysfunction, mostly within the spectrum of frontotemporal lobar degeneration (FTLD). Although there is an overlap in clinical manifestations of SD attributable to FTLD and neuropathologically proven Alzheimer disease (AD), clinical diagnostic clues are not readily available. We present a characteristic finding based on a single-photon emission computed tomography (SPECT)-based regional cerebral blood flow study and its statistical imaging analysis for a rare case of SD with AD-like pathology...
February 12, 2018: American Journal of Case Reports
Jennifer M Harris, Jennifer A Saxon, Matthew Jones, Julie S Snowden, Jennifer C Thompson
The differentiation of subtypes of primary progressive aphasia (PPA) remains challenging. We aimed to identify optimum neuropsychological measures for characterizing PPA, to examine the relationship between behavioural change and subtypes of PPA and to determine whether characteristic profiles of language, working memory, and behavioural changes occur in PPA. Forty-seven patients with PPA and multi-domain Alzheimer's disease (AD) together with 19 age-matched controls underwent a large battery of working memory and language tests...
February 8, 2018: Journal of Neuropsychology
Fiona Kumfor, Agustin Ibañez, Rosalind Hutchings, Jessica L Hazelton, John R Hodges, Olivier Piguet
The importance of assessing social cognition to characterize dementia syndromes is increasingly recognized, with lower social cognition capacity associated with reduced functional independence and greater carer burden. Emotion recognition is impaired in both behavioural-variant frontotemporal dementia and semantic dementia, yet the social and behavioural changes observed in these syndromes in everyday situations varies. To date, most studies have investigated isolated, context-free stimuli indexing recognition of facial emotions only...
January 31, 2018: Brain: a Journal of Neurology
Hannah E Thompson, Azizah Almaghyuli, Krist A Noonan, Ohr Barak, Matthew A Lambon Ralph, Elizabeth Jefferies
Semantic cognition, as described by the controlled semantic cognition (CSC) framework (Rogers et al., , Neuropsychologia, 76, 220), involves two key components: activation of coherent, generalizable concepts within a heteromodal 'hub' in combination with modality-specific features (spokes), and a constraining mechanism that manipulates and gates this knowledge to generate time- and task-appropriate behaviour. Executive-semantic goal representations, largely supported by executive regions such as frontal and parietal cortex, are thought to allow the generation of non-dominant aspects of knowledge when these are appropriate for the task or context...
January 3, 2018: Journal of Neuropsychology
Anna M Woollams, Karalyn Patterson
Semantic dementia (SD) is a condition in which atrophy to the anterior temporal lobes (ATL) produces a selective deterioration of conceptual knowledge. As this atrophy is always bilateral but usually asymmetrical, differences in performance of the two SD subgroups-with left > right (L > R) versus right > left (R > L) atrophy-constitute a major source of evidence regarding the roles of the left and right sides of this region. We explored this issue using large scale case-series methodology, with a pool of 216 observations of neuropsychological data from 72 patients with SD...
December 5, 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
Camilla N Clark, Hannah L Golden, Oliver McCallion, Jennifer M Nicholas, Miriam H Cohen, Catherine F Slattery, Ross W Paterson, Phillip D Fletcher, Catherine J Mummery, Jonathan D Rohrer, Sebastian J Crutch, Jason D Warren
Aberrant rule- and reward-based processes underpin abnormalities of socio-emotional behaviour in major dementias. However, these processes remain poorly characterised. Here we used music to probe rule decoding and reward valuation in patients with frontotemporal dementia syndromes and Alzheimer's disease relative to healthy age-matched individuals. We created short melodies that were either harmonically resolved ('finished') or unresolved ('unfinished'); the task was to classify each melody as finished or unfinished (rule processing) and rate its subjective pleasantness (reward valuation)...
November 24, 2017: Social Cognitive and Affective Neuroscience
Guillaume T Vallet, Carol Hudon, Nathalie Bier, Joël Macoir, Rémy Versace, Martine Simard
Embodiment has highlighted the importance of sensory-motor components in cognition. Perception and memory are thus very tightly bound together, and episodic and semantic memories should rely on the same grounded memory traces. Reduced perception should then directly reduce the ability to encode and retrieve an episodic memory, as in normal aging. Multimodal integration deficits, as in Alzheimer's disease, should lead to more severe episodic memory impairment. The present study introduces a new memory test developed to take into account these assumptions...
2017: Frontiers in Psychology
Catherine Merck, Isabelle Corouge, Pierre-Yves Jonin, Béatrice Desgranges, Jean-Yves Gauvrit, Serge Belliard
After demonstrating the relative preservation of fruit and vegetable knowledge in patients with semantic dementia (SD), we sought to identify the neural substrate of this unusual category effect. Nineteen patients with SD performed a semantic sorting task and underwent a morphometric 3T MRI scan. The grey-matter volumes of five regions within the temporal lobe were bilaterally computed, as well as those of two recently described areas (FG1 and FG2) within the posterior fusiform gyrus. In contrast to the other semantic categories we tested, fruit and vegetable scores were only predicted by left FG1 volume...
September 23, 2017: Neuropsychologia
Julie S Snowden, Jennifer M Harris, Jennifer C Thompson, Christopher Kobylecki, Matthew Jones, Anna M Richardson, David Neary
Semantic dementia, a circumscribed disorder of semantic knowledge, provides a unique model for understanding the neural basis for semantic representation. The study addressed areas of contention: the relative roles of the left and right temporal lobe, the contribution of anterior versus posterior temporal cortex and the status of the anterior temporal lobes as amodal hub. Naming and word comprehension was examined in 41 semantic dementia patients, 31 with left-predominant and 10 right-predominant atrophy. In keeping with expectation, naming and comprehension were significantly poorer in left-predominant patients...
August 31, 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
W R Bevan-Jones, Thomas E Cope, P Simon Jones, Luca Passamonti, Young T Hong, Tim D Fryer, Robert Arnold, Kieren S J Allinson, Jonathan P Coles, Franklin I Aigbirhio, Karalyn Patterson, John T O'Brien, James B Rowe
INTRODUCTION: Semantic dementia, including the semantic variant of primary progressive aphasia (svPPA), is strongly associated with TAR-DNA binding protein 43 (TDP-43) type C pathology. It provides a useful model in which to test the specificity of in vivo binding of the putative tau ligand [(18)F]AV-1451, which is elevated in frontotemporal lobar degeneration tauopathies. METHODS AND RESULTS: Seven patients (five with svPPA and two with 'right' semantic dementia) and 12 healthy controls underwent positron emission tomography brain imaging with [(18)F]AV-1451...
September 14, 2017: Journal of Neurology, Neurosurgery, and Psychiatry
Zhihong Shi, Shuai Liu, Ying Wang, Shuling Liu, Tong Han, Li Cai, Yuying Zhou, Shuo Gao, Yong Ji
The aim of the study was to obtain an overview of the clinical and neuroimaging features of Chinese patients with subtypes of frontotemporal lobe degeneration (FTLD).We evaluated the demographic features, clinical presentation, and lobe atrophy depicted by magnetic resonance imaging (MRI) in 133 patients with FTLD. Two positron emission tomography (PET) scans were performed at baseline: [C]Pittsburgh compound B PET to assess amyloid-β plaque load and [F]fluorodeoxyglucose (FDG) PET to assess glucose metabolism...
September 2017: Medicine (Baltimore)
Kalyan B Bhattacharyya
James Papez worked on the anatomical substrates of emotion and described a circuit, mainly composed of the hippocampus, thalamus and cingulum, and published his observations in 1937. However, such an idea existed before him, as evidenced by the rudimentary indications from Paul Broca, and Paul MacLean added some other structures like, septum, amygdala, and hypothalamus in its ambit and called it the limbic system. Paul Ivan Yakovlev, proposed a circuit which also referred to orbitofrontal, insular, anterior temporal lobe, and other nuclei of thalamus...
July 2017: Annals of Indian Academy of Neurology
Camilla N Clark, Jennifer M Nicholas, Jennifer L Agustus, Christopher J D Hardy, Lucy L Russell, Emilie V Brotherhood, Katrina M Dick, Charles R Marshall, Catherine J Mummery, Jonathan D Rohrer, Jason D Warren
Impaired analysis of signal conflict and congruence may contribute to diverse socio-emotional symptoms in frontotemporal dementias, however the underlying mechanisms have not been defined. Here we addressed this issue in patients with behavioural variant frontotemporal dementia (bvFTD; n = 19) and semantic dementia (SD; n = 10) relative to healthy older individuals (n = 20). We created auditory scenes in which semantic and emotional congruity of constituent sounds were independently probed; associated tasks controlled for auditory perceptual similarity, scene parsing and semantic competence...
September 2017: Neuropsychologia
Anna M Woollams, Lee J Lindley, Gorana Pobric, Paul Hoffman
The bilateral anterior temporal lobes play a key role in semantic representation. This is clearly demonstrated by the performance of patients with semantic dementia, a disorder characterised by a progressive and selective decline in semantic memory over all modalities as a result of anterior temporal atrophy. Although all patients exhibit a progressive decline in both single-word production and comprehension, those with greater atrophy to the left anterior temporal lobe show a stronger decline in word production than comprehension...
November 2017: Brain Structure & Function
Junhua Ding, Keliang Chen, Weibin Zhang, Ming Li, Yan Chen, Qing Yang, Yingru Lv, Qihao Guo, Zaizhu Han
BACKGROUND: Semantic dementia (SD) is characterized by a selective decline in semantic processing. Although the neuropsychological pattern of this disease has been identified, its topological global alterations and symptom-relevant modules in the whole-brain anatomical network have not been fully elucidated. OBJECTIVE: This study aims to explore the topological alteration of anatomical network in SD and reveal the modules associated with semantic deficits in this disease...
2017: Journal of Alzheimer's Disease: JAD
Yvonne S Davidson, Andrew C Robinson, Louis Flood, Sara Rollinson, Bridget C Benson, Yasmine T Asi, Anna Richardson, Matthew Jones, Julie S Snowden, Stuart Pickering-Brown, Tammaryn Lashley, David M A Mann
Frontotemporal Lobar Degeneration (FTLD) encompasses certain related neurodegenerative disorders which alter personality and cognition. Heterogeneous ribonuclear proteins (hnRNPs) maintain RNA metabolism and changes in their function may underpin the pathogenesis of FTLD. Immunostaining for hnRNP E2 was performed on sections of frontal and temporal cortex with hippocampus from 80 patients with FTLD, stratified by pathology into FTLD-tau and FTLD-TDP type A, B and C subtypes, and by genetics into patients with C9orf72 expansions, MAPT or GRN mutations, or those with no known mutation, and on 10 healthy controls...
June 30, 2017: Acta Neuropathologica Communications
Roland Zahn, Sophie Green, Helen Beaumont, Alistair Burns, Jorge Moll, Diana Caine, Alexander Gerhard, Paul Hoffman, Benjamin Shaw, Jordan Grafman, Matthew A Lambon Ralph
Inappropriate social behaviour is an early symptom of frontotemporal lobar degeneration (FTLD) in both behavioural variant frontotemporal dementia (bvFTD) and semantic dementia (SD) subtypes. Knowledge of social behaviour is essential for appropriate social conduct. The superior anterior temporal lobe (ATL) has been identified as one key neural component for the conceptual knowledge of social behaviour, but it is unknown whether this is dissociable from knowledge of the consequences of social behaviour. Here, we used a newly-developed test of knowledge about long-term and short-term consequences of social behaviour to investigate its impairment in patients with FTLD relative to a previously-developed test of social conceptual knowledge...
August 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
Zubaida Shebani, Karalyn Patterson, Peter J Nestor, Lara Z Diaz-de-Grenu, Kate Dawson, Friedemann Pulvermüller
There is general agreement that perisylvian language cortex plays a major role in lexical and semantic processing; but the contribution of additional, more widespread, brain areas in the processing of different semantic word categories remains controversial. We investigated word processing in two groups of patients whose neurodegenerative diseases preferentially affect specific parts of the brain, to determine whether their performance would vary as a function of semantic categories proposed to recruit those brain regions...
August 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
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