Differential language network functional connectivity alterations in Alzheimer's disease and the semantic variant of primary progressive aphasia

Background: Primary Progressive Aphasia (PPA) is characterized by progressive language impairment due to focal degeneration of brain areas related to linguistic processing. The detection and differential diagnosis of PPA can be difficult with clinical features that may overlap with features of other neurological conditions, such as Alzheimer's disease (AD). The scientific production on PPA in Latin American patients is still scarce. This study investigated the first symptoms in a Brazilian sample of patients with PPA in comparison with AD patients.Method: We compared the first symptoms reported by caregivers of people with PPA (n = 20; semantic variant n = 8, non-fluent variant n = 7, logopenic variant n = 3, and unclassified cases n = 2) and AD (n = 16). Data were collected through the application of a structured questionnaire that was presented in an interview format to the caregiver who knew the patient best.Results: Anomia, paraphasias and motor speech difficulties were the first symptoms capable of differentiating patients with PPA from those with AD, while memory was exclusive of AD. Among the PPA variants, anomia was the initial symptom associated with the semantic variant, while motor speech difficulties were associated with the non-fluent variant. The results are discussed considering the unique cultural and sociodemographic characteristics of this studied population.Conclusion: This study demonstrated that some of the initial symptoms of PPA patients may be unique to clinical variants of PPA and of AD, and their investigation may be useful for the early and differential diagnosis of this population.

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Naming unique entities in the semantic variant of primary progressive aphasia and Alzheimer's disease: Towards a better understanding of the semantic impairment

Neuropsychologia ◽

10.1016/j.neuropsychologia.2016.12.009 ◽

2017 ◽

Vol 95 ◽

pp. 11-20 ◽

Cited By ~ 13

Author(s):

M. Montembeault ◽

S.M. Brambati ◽

S. Joubert ◽

M. Boukadi ◽

M. Chapleau ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Primary Progressive Aphasia ◽

Progressive Aphasia ◽

Primary Progressive ◽

Semantic Variant ◽

Semantic Impairment

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Laughter as a Paradigm of Socio-emotional Signal Processing in Dementia

10.21203/rs.3.rs-118292/v1 ◽

2020 ◽

Author(s):

Harri Sivasathiaseelan ◽

Charles R Marshall ◽

Elia Benhamou ◽

Janneke EP van Leeuwen ◽

Rebecca L Bond ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Signal Processing ◽

Frontotemporal Dementia ◽

Primary Progressive Aphasia ◽

Identification Accuracy ◽

Progressive Aphasia ◽

Primary Progressive ◽

Emotional Dysfunction ◽

Semantic Variant

Abstract Background: Laughter is a fundamental communicative signal in our relations with other people and is used to convey a diverse repertoire of social and emotional information. It is therefore potentially a useful probe of impaired socio-emotional signal processing in neurodegenerative diseases. Here we investigated the cognitive and affective processing of laughter systematically in patients representing all major syndromes of frontotemporal dementia, a disease spectrum characterised by severe socio-emotional dysfunction, as well as typical amnestic Alzheimer’s disease in relation to healthy age-matched individuals. Methods: We assessed cognitive labelling and valence rating of samples of spontaneous (mirthful and hostile) and volitional (posed) laughter versus two auditory control conditions (a synthetic laughter-like stimulus and spoken numbers) in 47 patients with frontotemporal dementia (22 with behavioural variant frontotemporal dementia, 12 with semantic variant primary progressive aphasia and 13 with nonfluent-agrammatic primary progressive aphasia), 15 patients with typical amnestic Alzheimer’s disease and 20 healthy age-matched individuals. Neuroanatomical associations of laughter processing were assessed using voxel-based morphometry of patients’ brain MR images. Results: While all dementia syndromes were associated with impaired identification of laughter subtypes relative to healthy controls, this was significantly more severe overall in frontotemporal dementia than in Alzheimer’s disease and particularly in the behavioural and semantic variants, which also showed abnormal affective evaluation of laughter. Certain striking syndromic signatures emerged, including enhanced liking for hostile laughter in behavioural variant frontotemporal dementia, impaired processing of synthetic laughter in the nonfluent-agrammatic variant (consistent with a generic complex auditory perceptual deficit) and ‘numerophilia’ in the semantic variant. Across the patient cohort, overall laughter identification accuracy correlated with regional grey matter in a core network encompassing inferior frontal and cingulo-insular cortices; and more specific correlates of laughter identification accuracy were delineated in cortical regions mediating affective disambiguation (identification of hostile and posed laughter in orbitofrontal cortex) and authenticity (social intent) decoding (identification of mirthful and posed laughter in anteromedial prefrontal cortex).Conclusions: These findings reveal a rich diversity of cognitive and affective laughter phenotypes in canonical dementia syndromes and suggest that laughter is an informative probe of neural mechanisms underpinning socio-emotional dysfunction in neurodegenerative disease.

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Differential cognitive substrates of verbal episodic memory performance in semantic variant primary progressive aphasia and Alzheimer’s disease

Journal of Neuropsychology ◽

10.1111/jnp.12200 ◽

2020 ◽

Author(s):

Saskia DeVaughn ◽

Kaitlin B. Casaletto ◽

Adam M. Staffaroni ◽

Amy A. Wolf ◽

Gabe Marx ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Episodic Memory ◽

Memory Performance ◽

Primary Progressive Aphasia ◽

Progressive Aphasia ◽

Primary Progressive ◽

Semantic Variant ◽

Verbal Episodic Memory

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Deformation-based shape analysis of the hippocampus in the semantic variant of primary progressive aphasia and Alzheimer’s disease

NeuroImage Clinical ◽

10.1016/j.nicl.2020.102305 ◽

2020 ◽

Vol 27 ◽

pp. 102305 ◽

Cited By ~ 1

Author(s):

Marianne Chapleau ◽

Christophe Bedetti ◽

Gabriel A. Devenyi ◽

Signy Sheldon ◽

Howie J. Rosen ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Shape Analysis ◽

Primary Progressive Aphasia ◽

Progressive Aphasia ◽

Primary Progressive ◽

Semantic Variant

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Object decision test (BORB): normative data for the adult Quebec population and performance in Alzheimer’s disease and the semantic variant of primary progressive aphasia

Aging Neuropsychology and Cognition ◽

10.1080/13825585.2017.1319901 ◽

2017 ◽

Vol 25 (3) ◽

pp. 427-442 ◽

Cited By ~ 3

Author(s):

Alexandre St-Hilaire ◽

Marie-Claude Blackburn ◽

Maximiliano A. Wilson ◽

Robert Laforce ◽

Carol Hudon ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Normative Data ◽

Primary Progressive Aphasia ◽

Progressive Aphasia ◽

Primary Progressive ◽

Object Decision ◽

Semantic Variant ◽

And Performance

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Clinical Characteristic in Primary Progressive Aphasia in Relation to Alzheimer’s Disease Biomarkers

Journal of Alzheimer s Disease ◽

10.3233/jad-210392 ◽

2021 ◽

pp. 1-13

Author(s):

Sung Hoon Kang ◽

Hanna Cho ◽

Jiho Shin ◽

Hang-Rai Kim ◽

Young Noh ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Language Impairment ◽

Amyloid Β ◽

Primary Progressive Aphasia ◽

Cortical Atrophy ◽

Clinical Feature ◽

Progressive Aphasia ◽

Disease Biomarkers ◽

Primary Progressive

Background: Primary progressive aphasia (PPA) is associated with amyloid-β (Aβ) pathology. However, clinical feature of PPA based on Aβ positivity remains unclear. Objective: We aimed to assess the prevalence of Aβ positivity in patients with PPA and compare the clinical characteristics of patients with Aβ-positive (A+) and Aβ-negative (A–) PPA. Further, we applied Aβ and tau classification system (AT system) in patients with PPA for whom additional information of in vivo tau biomarker was available. Methods: We recruited 110 patients with PPA (41 semantic [svPPA], 27 non-fluent [nfvPPA], 32 logopenic [lvPPA], and 10 unclassified [ucPPA]) who underwent Aβ-PET imaging at multi centers. The extent of language impairment and cortical atrophy were compared between the A+ and A–PPA subgroups using general linear models. Results: The prevalence of Aβ positivity was highest in patients with lvPPA (81.3%), followed by ucPPA (60.0%), nfvPPA (18.5%), and svPPA (9.8%). The A+ PPA subgroup manifested cortical atrophy mainly in the left superior temporal/inferior parietal regions and had lower repetition scores compared to the A–PPA subgroup. Further, we observed that more than 90%(13/14) of the patients with A+ PPA had tau deposition. Conclusion: Our findings will help clinicians understand the patterns of language impairment and cortical atrophy in patients with PPA based on Aβ deposition. Considering that most of the A+ PPA patents are tau positive, understanding the influence of Alzheimer’s disease biomarkers on PPA might provide an opportunity for these patients to participate in clinical trials aimed for treating atypical Alzheimer’s disease.

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