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Ding J, Yang Q, Drossinos N, Guo Q. Advances in semantic dementia: Neuropsychology, pathology & neuroimaging. Ageing Res Rev 2024; 99:102375. [PMID: 38866186 DOI: 10.1016/j.arr.2024.102375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 06/03/2024] [Accepted: 06/04/2024] [Indexed: 06/14/2024]
Abstract
Semantic dementia is a kind of neurodegenerative disorder, characterized by prominent semantic impairments and anterior temporal lobe atrophy. Since 2010, more studies have devoted to this rare disorder, revealing that it is more complex than we think. Clinical advances include more specific findings of semantic impairments and other higher order cognitive deficits. Neuroimaging techniques can help revealing the different brain networks affected (both structurally and functionally) in this condition. Pathological and genetic studies have also found more complex situations of semantic dementia, which might explain the huge variance existing in semantic dementia. Moreover, the current diagnosis criteria mainly focus on semantic dementia's classical prototype. We further delineated the features of three subtypes of semantic dementia based on atrophy lateralization with three severity stages. In a broader background, as a part of the continuum of neurodegenerative disorders, semantic dementia is commonly compared with other resembling conditions. Therefore, we summarized the differential diagnosis between semantic dementia and them. Finally, we introduced the challenges and achievements of its diagnosis, treatment, care and cross cultural comparison. By providing a comprehensive picture of semantic dementia on different aspects of advances, we hope to deepen the understanding of semantic dementia and promote more inspirations on both clinical and theoretical studies about it.
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Affiliation(s)
- Junhua Ding
- Department of Gerontology, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Department of Psychology, University of Edinburgh, Edinburgh, UK
| | - Qing Yang
- Department of Rehabilitation, Hushan Hospital, Fudan University, Shanghai, China
| | - Niki Drossinos
- Division of Psychology, Communication and Human Neuroscience, University of Manchester, Manchester, UK
| | - Qihao Guo
- Department of Gerontology, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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Marier A, Dadar M, Bouhali F, Montembeault M. Irregular word reading as a marker of semantic decline in Alzheimer's disease: implications for premorbid intellectual ability measurement. Alzheimers Res Ther 2024; 16:96. [PMID: 38698406 PMCID: PMC11064305 DOI: 10.1186/s13195-024-01438-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 03/25/2024] [Indexed: 05/05/2024]
Abstract
BACKGROUND Irregular word reading has been used to estimate premorbid intelligence in Alzheimer's disease (AD) dementia. However, reading models highlight the core influence of semantic abilities on irregular word reading, which shows early decline in AD. The primary objective of this study is to ascertain whether irregular word reading serves as an indicator of cognitive and semantic decline in AD, potentially discouraging its use as a marker for premorbid intellectual abilities. METHOD Six hundred eighty-one healthy controls (HC), 104 subjective cognitive decline, 290 early and 589 late mild cognitive impairment (EMCI, LMCI) and 348 AD participants from the Alzheimer's Disease Neuroimaging Initiative were included. Irregular word reading was assessed with the American National Adult Reading Test (AmNART). Multiple linear regressions were conducted predicting AmNART score using diagnostic category, general cognitive impairment and semantic tests. A generalized logistic mixed-effects model predicted correct reading using extracted psycholinguistic characteristics of each AmNART words. Deformation-based morphometry was used to assess the relationship between AmNART scores and voxel-wise brain volumes, as well as with the volume of a region of interest placed in the left anterior temporal lobe (ATL), a region implicated in semantic memory. RESULTS EMCI, LMCI and AD patients made significantly more errors in reading irregular words compared to HC, and AD patients made more errors than all other groups. Across the AD continuum, as well as within each diagnostic group, irregular word reading was significantly correlated to measures of general cognitive impairment / dementia severity. Neuropsychological tests of lexicosemantics were moderately correlated to irregular word reading whilst executive functioning and episodic memory were respectively weakly and not correlated. Age of acquisition, a primarily semantic variable, had a strong effect on irregular word reading accuracy whilst none of the phonological variables significantly contributed. Neuroimaging analyses pointed to bilateral hippocampal and left ATL volume loss as the main contributors to decreased irregular word reading performances. CONCLUSIONS While the AmNART may be appropriate to measure premorbid intellectual abilities in cognitively unimpaired individuals, our results suggest that it captures current semantic decline in MCI and AD patients and may therefore underestimate premorbid intelligence. On the other hand, irregular word reading tests might be clinically useful to detect semantic impairments in individuals on the AD continuum.
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Affiliation(s)
- Anna Marier
- Douglas Research Centre & Department of Psychiatry, McGill University, 6875 Boulevard LaSalle, Montréal, QC, H4H 1R3, Canada
- Department of Psychology, Université de Montréal, Succursale Centre-Ville, Montréal, QC, C.P. 6128, H3C 3J7, Canada
| | - Mahsa Dadar
- Douglas Research Centre & Department of Psychiatry, McGill University, 6875 Boulevard LaSalle, Montréal, QC, H4H 1R3, Canada
| | | | - Maxime Montembeault
- Douglas Research Centre & Department of Psychiatry, McGill University, 6875 Boulevard LaSalle, Montréal, QC, H4H 1R3, Canada.
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Lan F, Roquet D, Dalton MA, El-Omar H, Ahmed RM, Piguet O, Irish M. Exploring graded profiles of hippocampal atrophy along the anterior-posterior axis in semantic dementia and Alzheimer's disease. Neurobiol Aging 2024; 135:70-78. [PMID: 38232501 DOI: 10.1016/j.neurobiolaging.2024.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 01/07/2024] [Accepted: 01/09/2024] [Indexed: 01/19/2024]
Abstract
Mounting evidence indicates marked hippocampal degeneration in semantic dementia (SD) however, the spatial distribution of hippocampal atrophy profiles in this syndrome remains unclear. Using a recently developed parcellation approach, we extracted hippocampal volumes from four distinct subregions running from anterior to posterior along the longitudinal axis (anterior, intermediate rostral, intermediate caudal, and posterior). Volumetric differences in hippocampal subregions were compared between 21 SD, 24 matched Alzheimer's disease (AD), and 27 healthy older Control participants. Despite comparable overall hippocampal volume loss, SD and AD groups diverged in terms of the magnitude of atrophy along the anterior-posterior axis of the hippocampus. Global hippocampal atrophy was observed in AD, with no discernible gradation or lateralisation. In contrast, SD patients displayed graded bilateral hippocampal atrophy, most pronounced on the left-hand side, and concentrated in anterior relative to posterior subregions. Finally, we found preliminary evidence that disease-specific vulnerability along the anterior-posterior axis of the hippocampus was associated with canonical clinical features of these syndromes.
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Affiliation(s)
- Fang Lan
- The University of Sydney, Brain and Mind Centre, Sydney, New South Wales, Australia; The University of Sydney, School of Psychology, Sydney, New South Wales, Australia
| | - Daniel Roquet
- The University of Sydney, Brain and Mind Centre, Sydney, New South Wales, Australia; The University of Sydney, School of Psychology, Sydney, New South Wales, Australia
| | - Marshall A Dalton
- The University of Sydney, Brain and Mind Centre, Sydney, New South Wales, Australia; The University of Sydney, School of Psychology, Sydney, New South Wales, Australia
| | - Hashim El-Omar
- The University of Sydney, Brain and Mind Centre, Sydney, New South Wales, Australia
| | - Rebekah M Ahmed
- The University of Sydney, Brain and Mind Centre, Sydney, New South Wales, Australia; Memory and Cognition Clinic, Department of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Olivier Piguet
- The University of Sydney, Brain and Mind Centre, Sydney, New South Wales, Australia; The University of Sydney, School of Psychology, Sydney, New South Wales, Australia
| | - Muireann Irish
- The University of Sydney, Brain and Mind Centre, Sydney, New South Wales, Australia; The University of Sydney, School of Psychology, Sydney, New South Wales, Australia.
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Lang M, Colby S, Ashby-Padial C, Bapna M, Jaimes C, Rincon SP, Buch K. An imaging review of the hippocampus and its common pathologies. J Neuroimaging 2024; 34:5-25. [PMID: 37872430 DOI: 10.1111/jon.13165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 10/07/2023] [Accepted: 10/12/2023] [Indexed: 10/25/2023] Open
Abstract
The hippocampus is a complex structure located in the mesial temporal lobe that plays a critical role in cognitive and memory-related processes. The hippocampal formation consists of the dentate gyrus, hippocampus proper, and subiculum, and its importance in the neural circuitry makes it a key anatomic structure to evaluate in neuroimaging studies. Advancements in imaging techniques now allow detailed assessment of hippocampus internal architecture and signal features that has improved identification and characterization of hippocampal abnormalities. This review aims to summarize the neuroimaging features of the hippocampus and its common pathologies. It provides an overview of the hippocampal anatomy on magnetic resonance imaging and discusses how various imaging techniques can be used to assess the hippocampus. The review explores neuroimaging findings related to hippocampal variants (incomplete hippocampal inversion, sulcal remnant and choroidal fissure cysts), and pathologies of neoplastic (astrocytoma and glioma, ganglioglioma, dysembryoplastic neuroepithelial tumor, multinodular and vacuolating neuronal tumor, and metastasis), epileptic (mesial temporal sclerosis and focal cortical dysplasia), neurodegenerative (Alzheimer's disease, progressive primary aphasia, and frontotemporal dementia), infectious (Herpes simplex virus and limbic encephalitis), vascular (ischemic stroke, arteriovenous malformation, and cerebral cavernous malformations), and toxic-metabolic (transient global amnesia and opioid-associated amnestic syndrome) etiologies.
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Affiliation(s)
- Min Lang
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Samantha Colby
- Department of Neurosurgery, University of Utah Health, Salt Lake City, Utah, USA
| | | | - Monika Bapna
- School of Medicine, Georgetown University, Washington, DC, USA
| | - Camilo Jaimes
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Sandra P Rincon
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Karen Buch
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
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Marier A, Dadar M, Bouhali F, Montembeault M. Irregular word reading as a marker of cognitive and semantic decline in Alzheimer's disease rather than an estimate of premorbid intellectual abilities. RESEARCH SQUARE 2023:rs.3.rs-3381469. [PMID: 37841870 PMCID: PMC10571618 DOI: 10.21203/rs.3.rs-3381469/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Background Irregular word reading has been used to estimate premorbid intelligence in Alzheimer's disease (AD) dementia. However, reading models highlight the core influence of semantic abilities on irregular word reading, which shows early decline in AD. The general aim of this study is to determine whether irregular word reading is a valid estimate of premorbid intelligence, or a marker of cognitive and semantic decline in AD. Method 681 healthy controls (HC), 104 subjective cognitive decline, 290 early and 589 late mild cognitive impairment (EMCI, LMCI) and 348 AD participants from the Alzheimer's Disease Neuroimaging Initiative were included. Irregular word reading was assessed with the American National Adult Reading Test (AmNART). Multiple linear regressions were conducted predicting AmNART score using diagnostic category, general cognitive impairment and semantic tests. A generalized logistic mixed-effects model predicted correct reading using extracted psycholinguistic characteristics of each AmNART words. Deformation-based morphometry was used to assess the relationship between AmNART scores and voxel-wise brain volumes, as well as with the volume of a region of interest placed in the left anterior temporal lobe (ATL). Results EMCI, LMCI and AD patients made significantly more errors in reading irregular words compared to HC, and AD patients made more errors than all other groups. Across the AD continuum, as well as within each diagnostic group, irregular word reading was significantly correlated to measures of general cognitive impairment / dementia severity. Neuropsychological tests of lexicosemantics were moderately correlated to irregular word reading whilst executive functioning and episodic memory were respectively weakly and not correlated. Age of acquisition, a primarily semantic variable, had a strong effect on irregular word reading accuracy whilst none of the phonological variables significantly contributed. Neuroimaging analyses pointed to bilateral hippocampal and left ATL volume loss as the main contributors to decreased irregular word reading performances. Conclusions Irregular word reading performances decline throughout the AD continuum, and therefore, premorbid intelligence estimates based on the AmNART should not be considered accurate in MCI or AD. Results are consistent with the theory of irregular word reading impairments as an indicator of disease severity and semantic decline.
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Affiliation(s)
- Anna Marier
- Department of Psychology, Université de Montréal, C.P. 6128, succursale Centre-Ville, Montréal, QC, Canada, H3C 3J7
| | - Mahsa Dadar
- Douglas Research Centre & Department of Psychiatry, McGill University, 6875 Boulevard LaSalle, Montréal, QC, Canada, H4H 1R3
| | | | - Maxime Montembeault
- Douglas Research Centre & Department of Psychiatry, McGill University, 6875 Boulevard LaSalle, Montréal, QC, Canada, H4H 1R3
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Mendez MF, Nasir I. Distinguishing Semantic Variant Primary Progressive Aphasia from Alzheimer’s Disease. J Alzheimers Dis Rep 2023; 7:227-234. [PMID: 37090957 PMCID: PMC10116168 DOI: 10.3233/adr-230010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 03/01/2023] [Indexed: 03/30/2023] Open
Abstract
The differentiation of semantic variant primary progressive aphasia from dementia and Alzheimer’s disease can be difficult, particularly when the semantic anomia is pronounced. This report describes a patient who presented with complaints of memory loss and proved to have prominent semantic loss of all types of nouns, common and proper, concrete and abstract, yet continued to live independently and maintain his activities of daily living. The evaluation was consistent for semantic variant primary progressive aphasia with degradation of semantic knowledge and focal anterior temporal atrophy and hypometabolism. This report summarizes the literature and discusses the differential diagnosis of this disorder from Alzheimer’s disease and related dementias.
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Affiliation(s)
- Mario F. Mendez
- Department of Neurology, Department of Psychiatry and Behavioral Sciences, David Geffen School of Medicine, University of California Los Angeles (UCLA), Neurology Service, Neurobehavior Unit, V.A. Greater Los Angeles Healthcare System, Los Angeles, CA, USA
- Correspondence to: Mario F. Mendez, MD, PhD, Neurobehavior Unit, V.A. Greater Los Angeles Healthcare Center, 11301 Wilshire Blvd., Los Angeles, CA 90073, USA. Tel.: +1 310 478 3711/Ext. 42696; Fax: +1 310 268 4181; E-mail:
| | - Imaad Nasir
- Department of Neurology, Department of Psychiatry and Behavioral Sciences, David Geffen School of Medicine, University of California Los Angeles (UCLA), Neurology Service, Neurobehavior Unit, V.A. Greater Los Angeles Healthcare System, Los Angeles, CA, USA
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Boccalini C, Carli G, Tondo G, Polito C, Catricalà E, Berti V, Bessi V, Sorbi S, Iannaccone S, Esposito V, Cappa SF, Perani D. Brain metabolic connectivity reconfiguration in the semantic variant of primary progressive aphasia. Cortex 2022; 154:1-14. [PMID: 35717768 DOI: 10.1016/j.cortex.2022.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 03/16/2022] [Accepted: 05/09/2022] [Indexed: 11/30/2022]
Abstract
Functional network-level alterations in the semantic variant of Primary Progressive Aphasia (sv-PPA) are relevant to understanding the clinical features and the neural spreading of the pathology. We assessed the effect of neurodegeneration on brain systems reorganization in early sv-PPA, using advanced brain metabolic connectivity approaches. Forty-four subjects with sv-PPA and forty-four age-matched healthy controls (HC) were included. We applied two multivariate approaches to [18F]FDG-PET data - i.e., sparse inverse covariance estimation and seed-based interregional correlation analysis - to assess the integrity of (i) the whole-brain metabolic connectivity and (ii) the connectivity of brain regions relevant for cognitive and behavioral functions. Whole-brain analysis revealed a global-scale connectivity reconfiguration in sv-PPA, with widespread changes in metabolic connections of frontal, temporal, and parietal regions. In comparison to HC, the seed-based analysis revealed a) functional isolation of the left anterior temporal lobe (ATL), b) decreases in temporo-occipital connections and contralateral homologous regions, c) connectivity increases to the dorsal parietal cortex from the spared posterior temporal cortex, d) a disruption of the large-scale limbic brain networks. In sv-PPA, the severe functional derangement of the left ATL may lead to an extensive connectivity reconfiguration, encompassing several brain regions, including those not yet affected by neurodegeneration. These findings support the hypothesis that in sv-PPA the focal vulnerability of the core region (i.e., ATL) can potentially drive the widespread cerebral connectivity changes, already present in the early phase.
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Affiliation(s)
- Cecilia Boccalini
- Vita-Salute San Raffaele University, Milan, Italy; In Vivo Human Molecular and Structural Neuroimaging Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Giulia Carli
- Vita-Salute San Raffaele University, Milan, Italy; In Vivo Human Molecular and Structural Neuroimaging Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Giacomo Tondo
- Vita-Salute San Raffaele University, Milan, Italy; In Vivo Human Molecular and Structural Neuroimaging Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Cristina Polito
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy; IRCCS Fondazione Don Carlo Gnocchi, Florence, Italy
| | | | - Valentina Berti
- Nuclear Medicine Unit, Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
| | - Valentina Bessi
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Sandro Sorbi
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy; IRCCS Fondazione Don Carlo Gnocchi, Florence, Italy
| | - Sandro Iannaccone
- Department of Rehabilitation and Functional Recovery, San Raffaele Hospital, Milan, Italy
| | | | - Stefano F Cappa
- University School for Advanced Studies (IUSS), Pavia, Italy; IRCCS Mondino Foundation, Pavia, Italy
| | - Daniela Perani
- Vita-Salute San Raffaele University, Milan, Italy; In Vivo Human Molecular and Structural Neuroimaging Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy; Nuclear Medicine Unit, San Raffaele Hospital, Milan, Italy.
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Meier EL. The role of disrupted functional connectivity in aphasia. HANDBOOK OF CLINICAL NEUROLOGY 2022; 185:99-119. [PMID: 35078613 DOI: 10.1016/b978-0-12-823384-9.00005-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Language is one of the most complex and specialized higher cognitive processes. Brain damage to the distributed, primarily left-lateralized language network can result in aphasia, a neurologic disorder characterized by receptive and/or expressive deficits in spoken and/or written language. Most often, aphasia is the consequence of stroke-termed poststroke aphasia (PSA)-yet, aphasia can also manifest due to neurodegenerative disease, specifically, a disorder called primary progressive aphasia (PPA). In recent years, functional connectivity neuroimaging studies have provided emerging evidence supporting theories regarding the relationships between language impairments, structural brain damage, and functional network properties in these two disorders. This chapter reviews the current evidence for the "network phenotype of stroke injury" hypothesis (Siegel et al., 2016) as it pertains to PSA and the "network degeneration hypothesis" (Seeley et al., 2009) as it pertains to PPA. Methodologic considerations for functional connectivity studies, limitations of the current functional connectivity literature in aphasia, and future directions are also discussed.
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Affiliation(s)
- Erin L Meier
- Department of Communication Sciences and Disorders, Northeastern University, Boston, MA, United States.
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Coemans S, Struys E, Vandenborre D, Wilssens I, Engelborghs S, Paquier P, Tsapkini K, Keulen S. A Systematic Review of Transcranial Direct Current Stimulation in Primary Progressive Aphasia: Methodological Considerations. Front Aging Neurosci 2021; 13:710818. [PMID: 34690737 PMCID: PMC8530184 DOI: 10.3389/fnagi.2021.710818] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 08/09/2021] [Indexed: 11/30/2022] Open
Abstract
A variety of tDCS approaches has been used to investigate the potential of tDCS to improve language outcomes, or slow down the decay of language competences caused by Primary Progressive Aphasia (PPA). The employed stimulation protocols and study designs in PPA are generally speaking similar to those deployed in post-stroke aphasic populations. These two etiologies of aphasia however differ substantially in their pathophysiology, and for both conditions the optimal stimulation paradigm still needs to be established. A systematic review was done and after applying inclusion and exclusion criteria, 15 articles were analyzed focusing on differences and similarities across studies especially focusing on PPA patient characteristics (age, PPA variant, language background), tDCS stimulation protocols (intensity, frequency, combined therapy, electrode configuration) and study design as recent reviews and group outcomes for individual studies suggest tDCS is an effective tool to improve language outcomes, while methodological approach and patient characteristics are mentioned as moderators that may influence treatment effects. We found that studies of tDCS in PPA have clinical and methodological and heterogeneity regarding patient populations, stimulation protocols and study design. While positive group results are usually found irrespective of these differences, the magnitude, duration and generalization of these outcomes differ when comparing stimulation locations, and when results are stratified according to the clinical variant of PPA. We interpret the results of included studies in light of patient characteristics and methodological decisions. Further, we highlight the role neuroimaging can play in study protocols and interpreting results and make recommendations for future work.
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Affiliation(s)
- Silke Coemans
- Clinical and Experimental Neurolinguistics, CLIEN, Vrije Universiteit Brussel, Brussels, Belgium
| | - Esli Struys
- Clinical and Experimental Neurolinguistics, CLIEN, Vrije Universiteit Brussel, Brussels, Belgium
- Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
| | - Dorien Vandenborre
- Department of Speech and Language Pathology, Thomas More University of Applied Sciences, Antwerp, Belgium
| | - Ineke Wilssens
- Department of Speech and Language Pathology, Thomas More University of Applied Sciences, Antwerp, Belgium
| | - Sebastiaan Engelborghs
- Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
- Department of Neurology, Universitair Ziekenhuis Brussel, Brussels, Belgium
- Reference Center for Biological Markers of Dementia, BIODEM, Institute Born-Bunge, Universiteit Antwerpen, Antwerp, Belgium
| | - Philippe Paquier
- Clinical and Experimental Neurolinguistics, CLIEN, Vrije Universiteit Brussel, Brussels, Belgium
- Center for Research in Cognition and Neurosciences (CRCN), Université Libre de Bruxelles, Antwerp, Belgium
- Department of Translational Neurosciences (TNW), Universiteit Antwerpen, Antwerp, Belgium
| | - Kyrana Tsapkini
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, United States
- Department of Cognitive Science, Johns Hopkins University, Baltimore, MD, United States
| | - Stefanie Keulen
- Clinical and Experimental Neurolinguistics, CLIEN, Vrije Universiteit Brussel, Brussels, Belgium
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Zhang J, Zhang Y, Pan Y, Xu Y, Xue Y. The neural foundation of associative memory: a dynamic functional connectivity study for right-handed young adults. Exp Brain Res 2021; 239:3527-3536. [PMID: 34537860 DOI: 10.1007/s00221-021-06222-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 09/12/2021] [Indexed: 11/30/2022]
Abstract
The medial temporal lobe (MTL) is the core neural construction related to associative memory. This study sought to explore the dynamic functional connectivity (dFC) between the subdivisions of MTL and other regions in the whole brain. Additionally, it sought to determine relationships between connectivity stability and associative memory function, to elucidate the neural foundation of associative memory from the perspectives of dFC. A Wechsler Memory Scale China revised edition (WMS-RC) measurement and a resting-state functional magnetic resonance imaging were conducted to clarify adults' function of associative memory and dFC patterns in subdivisions of the MTL. A multiple regression analysis was carried out to analyze the relationships described above. The results demonstrated that (i) connectivity in the left brain included the anterior hippocampus (aHIP) and right fusiform (Fusiform_R), middle hippocampus (mHIP) and right inferior parietal lobule (IPL_R), posterior hippocampus (pHIP) and left inferior parietal lobule (IPL_L), perirhinal cortex (PRC) and left supramarginal gyrus (SMG_L), entorhinal cortex (ERC) and [left middle temporal gyrus (MTG_L), left superior parietal lobule (SPL_L), right fusiform (Fusiform_R)], anterior parahippocampal cortex (aPHC) and right precentral gyrus (PCG_R); (ii) connectivity in the right brain included the aHIP and right supramarginal gyrus (SMG_R), mHIP and left paracentral lobule (PCL_L), pHIP and left superior occipital gyrus (SOG_L), PRC and left middle occipital gyrus (MOG_L), ERC and right middle occipital gyrus (MOG_R); (iii) for most connectivity patterns, the more stable the dFC, the better are the associative memory functions. This study elucidates the neural foundations of associative memory in terms of dFC patterns.
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Affiliation(s)
- Jian Zhang
- School of Psychology, Guizhou Normal University, Guiyang, People's Republic of China
| | - Yujia Zhang
- Department of Community Prevention, Tianjin Anding Hospital, Tianjin, People's Republic of China
| | - Yun Pan
- School of Psychology, Guizhou Normal University, Guiyang, People's Republic of China
| | - Yong Xu
- Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, 85 Jiefang South Road, Taiyuan, 030001, People's Republic of China. .,MDT Center for Cognitive Impairment and Sleep Disorders, First Hospital of Shanxi Medical University, Taiyuan, People's Republic of China.
| | - Yunzhen Xue
- Department of Humanities and Social Science, Shanxi Medical University, 56 Xinjian South Road, Taiyuan, 030001, People's Republic of China.
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Abstract
BACKGROUND Semantic dementia (SD) is characterized by progressive semantic anomia extending to a multimodal loss of semantic knowledge. Although often considered an early-onset dementia, SD also occurs in later life, when it may be misdiagnosed as Alzheimer disease (AD). OBJECTIVE To evaluate late-onset SD in comparison to early-onset SD and to AD. METHODS We identified 74 individuals with SD and then compared those with late-onset SD (≥65 years of age) to those with early-onset SD (<65) on demographic and clinical features. We also compared a subgroup of 23 of the late-onset SD individuals with an equal number of individuals with clinically probable AD. RESULTS Twenty-six (35.1%) of the SD individuals were late onset, and 48 (64.9%) were early onset. There were no differences between the two groups on clinical measures, although greater asymmetry of temporal involvement trended to significance in the late-onset SD group. Compared to the 23 AD individuals, the subgroup of 23 late-onset SD individuals had worse performance on confrontational naming, irregular word reading, and face recognition; however, this subgroup displayed better verbal delayed recall and constructions. The late-onset SD individuals also experienced early personality changes at a time when most individuals with AD had not yet developed behavioral changes. CONCLUSIONS Approximately one-third of SD individuals may be late onset, and the differentiation of late-onset SD from AD can lead to better disease management, education, and prognosis. SD may be distinguished by screening for disproportionate changes in reading, face recognition, and personality.
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Chapleau M, Bedetti C, Devenyi GA, Sheldon S, Rosen HJ, Miller BL, Gorno-Tempini ML, Chakravarty MM, Brambati SM. Deformation-based shape analysis of the hippocampus in the semantic variant of primary progressive aphasia and Alzheimer's disease. Neuroimage Clin 2020; 27:102305. [PMID: 32544853 PMCID: PMC7298722 DOI: 10.1016/j.nicl.2020.102305] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 05/30/2020] [Accepted: 06/01/2020] [Indexed: 01/18/2023]
Abstract
BACKGROUND Increasing evidence shows that the semantic variant of primary progressive aphasia (svPPA) is characterized by hippocampal atrophy. However, less is known about disease-related morphological hippocampal changes. The goal of the present study is to conduct a detailed characterization of the impact of svPPA on global hippocampus volume and morphology compared with control subjects and patients with Alzheimer's disease (AD). METHODS We measured hippocampal volume and deformation-based shape differences in 22 patients with svPPA compared with 99 patients with AD and 92 controls. Multiple Automatically Generated Templates Brain Segmentation Algorithm (MAGeT-Brain) was used on MRI images obtained at the diagnostic visit. RESULTS Comparable left and right hippocampal atrophy were observed in svPPA and AD. Deformation-based shape analysis showed a common pattern of morphological deformation in svPPA and AD compared with controls. More specifically, both svPPA and AD showed inward deformations in the dorsal surface of the hippocampus, from head to tail on the left side, and more limited to the anterior portion of the body in the right hemisphere. These results also pointed out that both diseases are characterized by a lateral displacement of the central part (body) of the hippocampus. DISCUSSION Our study provides critical new evidence of hippocampal morphological changes in svPPA, similar to those found in AD. These findings highlight the importance of considering morphological hippocampal changes as part of the anatomical profile of patients with svPPA.
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Affiliation(s)
- Marianne Chapleau
- Department of Psychology, University of Montreal, Quebec, Canada; Research Center of l'Institut Universitaire de Gériatrie de Montréal, Quebec, Canada
| | - Christophe Bedetti
- Department of Psychology, University of Montreal, Quebec, Canada; Research Center of l'Institut Universitaire de Gériatrie de Montréal, Quebec, Canada
| | - Gabriel A Devenyi
- Computational Brain Anatomy Lab, Cerebral Imaging Center, Douglas Mental Health University Institute, Quebec, Canada; Department of Psychiatry, McGill University, Quebec, Canada
| | - Signy Sheldon
- Department of Psychology, McGill University, Quebec, Canada
| | - Howie J Rosen
- Memory and Aging Center, University of California in San Francisco, CA, USA
| | - Bruce L Miller
- Memory and Aging Center, University of California in San Francisco, CA, USA
| | | | - Mallar M Chakravarty
- Computational Brain Anatomy Lab, Cerebral Imaging Center, Douglas Mental Health University Institute, Quebec, Canada; Department of Psychiatry, McGill University, Quebec, Canada; Department of Biological and Biomedical Engineering, McGill University, Quebec, Canada
| | - Simona M Brambati
- Department of Psychology, University of Montreal, Quebec, Canada; Research Center of l'Institut Universitaire de Gériatrie de Montréal, Quebec, Canada.
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