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Ulugut H, Dijkstra AA, Scarioni M, Barkhof F, Scheltens P, Rozemuller AJM, Pijnenburg YAL. Right temporal variant frontotemporal dementia is pathologically heterogeneous: a case-series and a systematic review. Acta Neuropathol Commun 2021; 9:131. [PMID: 34344452 PMCID: PMC8330072 DOI: 10.1186/s40478-021-01229-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 07/12/2021] [Indexed: 12/11/2022] Open
Abstract
Although the right temporal variant frontotemporal dementia (rtvFTD) is characterised by distinct clinical and radiological features, its underlying histopathology remains elusive. Being considered a right-sided variant of semantic variant primary progressive aphasia (svPPA), TDP-43 type C pathology has been linked to the syndrome, but this has not been studied in detail in large cohorts. In this case report and systematic review, we report the autopsy results of five subjects diagnosed with rtvFTD from our cohort and 44 single rtvFTD subjects from the literature. Macroscopic pathological evaluation of the combined results revealed that rtvFTD demonstrated either a frontotemporal or temporal evolution, even if the degeneration started in the right temporal lobe initially. FTLD-TDP type C was the most common underlying pathology in rtvFTD, however, in 64% of rtvFTD, other underlying pathologies than FTLD-TDP type C were present, such as Tau-MAPT and FTLD-TDP type A and B. Additionally, accompanying motor neuron or corticospinal tract degeneration was observed in 28% of rtvFTD patients. Our results show that in contrast to the general assumption, rtvFTD might not be a pure FTLD-TDP type C disorder, unlike its left temporal counterpart svPPA. Large sample size pathological studies are warranted to understand the diverse pathologies of the right and left temporal variants of frontotemporal dementia.
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Pascual B, Funk Q, Zanotti-Fregonara P, Cykowski MD, Veronese M, Rockers E, Bradbury K, Yu M, Nakawah MO, Román GC, Schulz PE, Arumanayagam AS, Beers D, Faridar A, Fujita M, Appel SH, Masdeu JC. Neuroinflammation is highest in areas of disease progression in semantic dementia. Brain 2021; 144:1565-1575. [PMID: 33824991 DOI: 10.1093/brain/awab057] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 11/25/2020] [Accepted: 12/10/2020] [Indexed: 12/11/2022] Open
Abstract
Despite epidemiological and genetic data linking semantic dementia to inflammation, the topography of neuroinflammation in semantic dementia, also known as the semantic variant of primary progressive aphasia, remains unclear. The pathology starts at the tip of the left temporal lobe where, in addition to cortical atrophy, a strong signal appears with the tau PET tracer 18F-flortaucipir, even though the disease is not typically associated with tau but with TDP-43 protein aggregates. Here, we characterized the topography of inflammation in semantic variant primary progressive aphasia using high-resolution PET and the tracer 11C-PBR28 as a marker of microglial activation. We also tested the hypothesis that inflammation, by providing non-specific binding targets, could explain the 18F-flortaucipir signal in semantic variant primary progressive aphasia. Eight amyloid-PET-negative patients with semantic variant primary progressive aphasia underwent 11C-PBR28 and 18F-flortaucipir PET. Healthy controls underwent 11C-PBR28 PET (n = 12) or 18F-flortaucipir PET (n = 12). Inflammation in PET with 11C-PBR28 was analysed using Logan graphical analysis with a metabolite-corrected arterial input function. 18F-flortaucipir standardized uptake value ratios were calculated using the cerebellum as the reference region. Since monoamine oxidase B receptors are expressed by astrocytes in affected tissue, selegiline was administered to one patient with semantic variant primary progressive aphasia before repeating 18F-flortaucipir scanning to test whether monoamine oxidase B inhibition blocked flortaucipir binding, which it did not. While 11C-PBR28 uptake was mostly cortical, 18F-flortaucipir uptake was greatest in the white matter. The uptake of both tracers was increased in the left temporal lobe and in the right temporal pole, as well as in regions adjoining the left temporal pole such as insula and orbitofrontal cortex. However, peak uptake of 18F-flortaucipir localized to the left temporal pole, the epicentre of pathology, while the peak of inflammation 11C-PBR28 uptake localized to a more posterior, mid-temporal region and left insula and orbitofrontal cortex, in the periphery of the damage core. Neuroinflammation, greatest in the areas of progression of the pathological process in semantic variant primary progressive aphasia, should be further studied as a possible therapeutic target to slow disease progression.
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Affiliation(s)
- Belen Pascual
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Quentin Funk
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Paolo Zanotti-Fregonara
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Matthew D Cykowski
- Department of Pathology and Genomic Medicine, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA.,Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Mattia Veronese
- Centre for Neuroimaging Sciences, King's College London, London, UK
| | - Elijah Rockers
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Kathleen Bradbury
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Meixiang Yu
- Cyclotron and Radiopharmaceutical Core, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Mohammad O Nakawah
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Gustavo C Román
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Paul E Schulz
- Department of Neurology, McGovern Medical School of UT Health, Houston, TX, USA
| | - Anithachristy S Arumanayagam
- Department of Pathology and Genomic Medicine, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - David Beers
- Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Alireza Faridar
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Masahiro Fujita
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Stanley H Appel
- Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Joseph C Masdeu
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
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Ruksenaite J, Volkmer A, Jiang J, Johnson JC, Marshall CR, Warren JD, Hardy CJ. Primary Progressive Aphasia: Toward a Pathophysiological Synthesis. Curr Neurol Neurosci Rep 2021; 21:7. [PMID: 33543347 PMCID: PMC7861583 DOI: 10.1007/s11910-021-01097-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2021] [Indexed: 12/14/2022]
Abstract
PURPOSE OF REVIEW The term primary progressive aphasia (PPA) refers to a diverse group of dementias that present with prominent and early problems with speech and language. They present considerable challenges to clinicians and researchers. RECENT FINDINGS Here, we review critical issues around diagnosis of the three major PPA variants (semantic variant PPA, nonfluent/agrammatic variant PPA, logopenic variant PPA), as well as considering 'fragmentary' syndromes. We next consider issues around assessing disease stage, before discussing physiological phenotyping of proteinopathies across the PPA spectrum. We also review evidence for core central auditory impairments in PPA, outline critical challenges associated with treatment, discuss pathophysiological features of each major PPA variant, and conclude with thoughts on key challenges that remain to be addressed. New findings elucidating the pathophysiology of PPA represent a major step forward in our understanding of these diseases, with implications for diagnosis, care, management, and therapies.
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Affiliation(s)
- Justina Ruksenaite
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, 8 - 11 Queen Square, London, WC1N 3BG, UK
| | - Anna Volkmer
- Division of Psychology and Language Sciences, University College London, London, UK
| | - Jessica Jiang
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, 8 - 11 Queen Square, London, WC1N 3BG, UK
| | - Jeremy Cs Johnson
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, 8 - 11 Queen Square, London, WC1N 3BG, UK
| | - Charles R Marshall
- Preventive Neurology Unit, Wolfson Institute of Preventive Medicine, Queen Mary University of London, London, UK
| | - Jason D Warren
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, 8 - 11 Queen Square, London, WC1N 3BG, UK
| | - Chris Jd Hardy
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, 8 - 11 Queen Square, London, WC1N 3BG, UK.
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Tse NY, Chen Y, Irish M, Cordato NJ, Landin-Romero R, Hodges JR, Piguet O, Ahmed RM. Cerebellar contributions to cognition in corticobasal syndrome and progressive supranuclear palsy. Brain Commun 2021; 2:fcaa194. [PMID: 33381758 PMCID: PMC7753056 DOI: 10.1093/braincomms/fcaa194] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 10/05/2020] [Accepted: 10/13/2020] [Indexed: 01/02/2023] Open
Abstract
Mounting evidence suggests an association between cerebellar atrophy and cognitive impairment in the main frontotemporal dementia syndromes. In contrast, whether cerebellar atrophy is present in the motor syndromes associated with frontotemporal lobar degeneration (corticobasal syndrome and progressive supranuclear palsy) and the extent of its contribution to their cognitive profile remain poorly understood. The current study aimed to comprehensively chart profiles of cognitive impairment in relation to cerebellar atrophy in 49 dementia patients (corticobasal syndrome = 33; progressive supranuclear palsy = 16) compared to 33 age-, sex- and education-matched healthy controls. Relative to controls, corticobasal syndrome and progressive supranuclear palsy patients demonstrated characteristic cognitive impairment, spanning the majority of cognitive domains including attention and processing speed, language, working memory, and executive function with relative preservation of verbal and nonverbal memory. Voxel-based morphometry analysis revealed largely overlapping patterns of cerebellar atrophy in corticobasal syndrome and progressive supranuclear palsy relative to controls, primarily involving bilateral Crus II extending into adjacent lobules VIIb and VIIIa. After controlling for overall cerebral atrophy and disease duration, exploratory voxel-wise general linear model analysis revealed distinct cerebellar subregions differentially implicated across cognitive domains in each patient group. In corticobasal syndrome, reduction in grey matter intensity in the left Crus I was significantly correlated with executive dysfunction. In progressive supranuclear palsy, integrity of the vermis and adjacent right lobules I-IV was significantly associated with language performance. These results are consistent with the well-established role of Crus I in executive functions and provide further supporting evidence for vermal involvement in cognitive processing. The current study presents the first detailed exploration of the role of cerebellar atrophy in cognitive deficits in corticobasal syndrome and progressive supranuclear palsy, offering insights into the cerebellum's contribution to cognitive processing even in neurodegenerative syndromes characterized by motor impairment.
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Affiliation(s)
- Nga Yan Tse
- Central Sydney Medical School and Brain and Mind Centre, The University of Sydney, Sydney, Australia
| | - Yu Chen
- School of Psychology and Brain and Mind Centre, The University of Sydney, Sydney, Australia
| | - Muireann Irish
- School of Psychology and Brain and Mind Centre, The University of Sydney, Sydney, Australia
| | - Nicholas J Cordato
- Faculty of Medicine, The University of New South Wales, Sydney, Australia.,The Department of Aged Care, St George Hospital, Kogarah, Australia.,Calvary Health Care Sydney, Kogarah, Australia
| | - Ramon Landin-Romero
- School of Psychology and Brain and Mind Centre, The University of Sydney, Sydney, Australia
| | - John R Hodges
- Central Sydney Medical School and Brain and Mind Centre, The University of Sydney, Sydney, Australia
| | - Olivier Piguet
- School of Psychology and Brain and Mind Centre, The University of Sydney, Sydney, Australia
| | - Rebekah M Ahmed
- Central Sydney Medical School and Brain and Mind Centre, The University of Sydney, Sydney, Australia.,Memory and Cognition Clinic, Department of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney, Australia
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Murley AG, Coyle-Gilchrist I, Rouse MA, Jones PS, Li W, Wiggins J, Lansdall C, Rodríguez PV, Wilcox A, Tsvetanov KA, Patterson K, Lambon Ralph MA, Rowe JB. Redefining the multidimensional clinical phenotypes of frontotemporal lobar degeneration syndromes. Brain 2020; 143:1555-1571. [PMID: 32438414 PMCID: PMC7241953 DOI: 10.1093/brain/awaa097] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 01/14/2020] [Accepted: 02/07/2020] [Indexed: 12/14/2022] Open
Abstract
The syndromes caused by frontotemporal lobar degeneration have highly heterogeneous and overlapping clinical features. There has been great progress in the refinement of clinical diagnostic criteria in the past decade, but we propose that a better understanding of aetiology, pathophysiology and symptomatic treatments can arise from a transdiagnostic approach to clinical phenotype and brain morphometry. In a cross-sectional epidemiological study, we examined 310 patients with a syndrome likely to be caused by frontotemporal lobar degeneration, including behavioural variant frontotemporal dementia, non-fluent, and semantic variants of primary progressive aphasia (PPA), progressive supranuclear palsy and corticobasal syndrome. We included patients with logopenic PPA and those who met criteria for PPA but not a specific subtype. To date, 49 patients have a neuropathological diagnosis. A principal component analysis identified symptom dimensions that broadly recapitulated the core features of the main clinical syndromes. However, the subject-specific scores on these dimensions showed considerable overlap across the diagnostic groups. Sixty-two per cent of participants had phenotypic features that met the diagnostic criteria for more than one syndrome. Behavioural disturbance was prevalent in all groups. Forty-four per cent of patients with corticobasal syndrome had progressive supranuclear palsy-like features and 30% of patients with progressive supranuclear palsy had corticobasal syndrome-like features. Many patients with progressive supranuclear palsy and corticobasal syndrome had language impairments consistent with non-fluent variant PPA while patients with behavioural variant frontotemporal dementia often had semantic impairments. Using multivariate source-based morphometry on a subset of patients (n = 133), we identified patterns of covarying brain atrophy that were represented across the diagnostic groups. Canonical correlation analysis of clinical and imaging components found three key brain-behaviour relationships, with a continuous spectrum across the cohort rather than discrete diagnostic entities. In the 46 patients with follow-up (mean 3.6 years) syndromic overlap increased with time. Together, these results show that syndromes associated with frontotemporal lobar degeneration do not form discrete mutually exclusive categories from their clinical features or structural brain changes, but instead exist in a multidimensional spectrum. Patients often manifest diagnostic features of multiple disorders while deficits in behaviour, movement and language domains are not confined to specific diagnostic groups. It is important to recognize individual differences in clinical phenotype, both for clinical management and to understand pathogenic mechanisms. We suggest that a transdiagnostic approach to the spectrum of frontotemporal lobar degeneration syndromes provides a useful framework with which to understand disease aetiology, progression, and heterogeneity and to target future treatments to a higher proportion of patients.
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Affiliation(s)
- Alexander G Murley
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Ian Coyle-Gilchrist
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Norfolk and Norwich NHS Foundation Trust, Norwich, UK
| | - Matthew A Rouse
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - P Simon Jones
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Win Li
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Julie Wiggins
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Claire Lansdall
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | | | - Alicia Wilcox
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Kamen A Tsvetanov
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Karalyn Patterson
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
| | - Matthew A Lambon Ralph
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
| | - James B Rowe
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
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