Data-driven classification of patients with primary progressive aphasia.
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ABSTRACT:
SUBMITTER: Hoffman P
PROVIDER: S-EPMC5626563 | biostudies-literature | 2017 Nov
REPOSITORIES: biostudies-literature
Publications
Data-driven classification of patients with primary progressive aphasia.
Hoffman Paul P Sajjadi Seyed Ahmad SA Patterson Karalyn K Nestor Peter J PJ
Brain and language 20170810
Current diagnostic criteria classify primary progressive aphasia into three variants-semantic (sv), nonfluent (nfv) and logopenic (lv) PPA-though the adequacy of this scheme is debated. This study took a data-driven approach, applying k-means clustering to data from 43 PPA patients. The algorithm grouped patients based on similarities in language, semantic and non-linguistic cognitive scores. The optimum solution consisted of three groups. One group, almost exclusively those diagnosed as svPPA, ...[more]
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Project description:The aim is to explore the evolution of the logopenic variant of primary progressive aphasia as a distinct clinical entity and to outline recent advances that have clarified its clinical characteristics, neural underpinnings, and potential genetic and pathological bases. This is particularly relevant as researchers attempt to identify clinico-pathological relationships in subtypes of primary progressive aphasia in hopes of utilizing language phenotype as a marker of underlying disease.Recent work has served to refine and expand upon the clinical phenotype of the logopenic variant. Logopenic patients show a unique pattern of spared and impaired language processes that reliably distinguish this syndrome from other variants of progressive aphasia. Specifically, they exhibit deficits in naming and repetition in the context of spared semantic, syntactic, and motor speech abilities. Further, there is a growing body of evidence indicating a possible link between the logopenic phenotype and specific pathological and genetic correlates.Findings indicate that the logopenic variant is a distinct subtype of progressive aphasia that may hold value as a predictor of underlying pathology. Additional research, however, is warranted in order to further clarify the cognitive-linguistic profile and to confirm its relation to certain pathological and genetic processes.
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Project description:PURPOSE OF REVIEW:Knowledge on primary progressive aphasia (PPA) has expanded rapidly in the past few decades. Clinical characteristics, neuroimaging correlates, and neuropathological features of PPA are better delineated. This facilitates scientific studies on the disease pathophysiology and allows speech and language therapy to be more precisely targeted. This review article begins with a summary of the current understanding of PPA and discusses how PPA can serve as a model to promote scientific discovery in neurodegenerative diseases. RECENT FINDINGS:Studies on the different variants of PPA have demonstrated the high compatibility between clinical presentations and neuroimaging features, and in turn, enhances the understanding of speech and language neuroanatomy. In addition to the traditional approach of lesion-based or voxel-based mapping, scientists have also adopted functional connectivity and network topology approaches that permits a more multidimensional understanding of neuroanatomy. As a result, pharmacological and cognitive therapeutic strategies can now be better targeted towards specific pathological/molecular and cognitive subtypes. SUMMARY:Recent scientific advancement in PPA potentiates it to be an optimal model for studying brain network vulnerability, neurodevelopment influences and the effects of nonpharmacological intervention in neurodegenerative diseases.
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