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dc.contributor.authorRamanan, Siddharthen
dc.contributor.authorRoquet, Danielen
dc.contributor.authorGoldberg, Zoë-Leeen
dc.contributor.authorHodges, John Ren
dc.contributor.authorPiguet, Olivieren
dc.contributor.authorIrish, Muireannen
dc.contributor.authorLambon Ralph, Matthewen
dc.date.accessioned2020-10-15T23:30:24Z
dc.date.available2020-10-15T23:30:24Z
dc.date.issued2020-01en
dc.identifier.issn2632-1297
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/311571
dc.description.abstractLogopenic Progressive Aphasia (LPA) is a neurodegenerative syndrome characterised by sentence repetition and naming difficulties arising from left-lateralised temporoparietal atrophy. Clinical descriptions of LPA largely concentrate on profiling language deficits, however, accumulating evidence points to the presence of cognitive deficits, even on tasks with minimal language demands. Although non-linguistic cognitive deficits in LPA are thought to scale with disease severity, patients at discrete stages of language dysfunction display overlapping cognitive profiles, suggesting individual-level variation in cognitive performance, independent of primary language dysfunction. To address this issue, we used principal component analysis to decompose individual-level variation in cognitive performance in 43 well-characterised LPA patients who underwent multi-domain neuropsychological assessments and structural neuroimaging. The principal component analysis solution revealed the presence of two, statistically independent factors, providing stable and clinically intuitive explanations for the majority of variance in cognitive performance in the syndrome. Factor 1 reflected ‘speech production and verbal memory’ deficits which typify LPA. Systematic variations were also confirmed on a second, orthogonal factor mainly comprising visuospatial and executive processes. Adopting a case-comparison approach, we further demonstrate that pairs of patients with comparable Factor 1 scores, regardless of their severity, diverge considerably on visuo-executive test performance, underscoring the inter-individual variability in cognitive profiles in comparably ‘logopenic’ patients. Whole-brain voxel-based morphometry analyses revealed that speech production and verbal memory factor scores correlated with left middle frontal gyrus, while visuospatial and executive factor scores were associated with grey matter intensity of right-lateralised temporoparietal, middle frontal regions and their underlying white matter connectivity. Importantly, LPA patients with poorer visuospatial and executive factor scores demonstrated greater right-lateralised temporoparietal and frontal atrophy. Our findings demonstrate the inherent variation in cognitive performance at an individual- and group-level in LPA, suggesting the presence of a genuine co-occurring cognitive impairment that is independent of language function and disease severity.
dc.format.mediumElectronic-eCollectionen
dc.languageengen
dc.publisherOxford University Press
dc.rightsAll rights reserved
dc.rights.uri
dc.titleEstablishing two principal dimensions of cognitive variation in logopenic progressive aphasia.en
dc.typeArticle
prism.issueIdentifier2en
prism.publicationDate2020en
prism.publicationNameBrain communicationsen
prism.startingPagefcaa125
prism.volume2en
dc.identifier.doi10.17863/CAM.58663
dcterms.dateAccepted2020-07-13en
rioxxterms.versionofrecord10.1093/braincomms/fcaa125en
rioxxterms.versionAM
rioxxterms.licenseref.urihttp://www.rioxx.net/licenses/all-rights-reserveden
rioxxterms.licenseref.startdate2020-01en
dc.contributor.orcidRamanan, Siddharth [0000-0002-8591-042X]
dc.contributor.orcidIrish, Muireann [0000-0002-4950-8169]
dc.contributor.orcidLambon Ralph, Matthew [0000-0001-5907-2488]
dc.identifier.eissn2632-1297
rioxxterms.typeJournal Article/Reviewen
pubs.funder-project-idMRC (Unknown)
pubs.funder-project-idMRC (MR/R023883/1)
pubs.funder-project-idEuropean Commission Horizon 2020 (H2020) ERC (670428)
cam.orpheus.counter17*
rioxxterms.freetoread.startdate2023-10-15


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