scholarly journals Neural Correlates of Letter and Semantic Fluency in Primary Progressive Aphasia

2021 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Marianna Riello ◽  
Constantine E. Frangakis ◽  
Bronte Ficek ◽  
Kimberly T. Webster ◽  
John E. Desmond ◽  
...  
Keyword(s):  
Cognitive Task ◽  
Critical Role ◽  
Demographic Factors ◽  
Primary Progressive Aphasia ◽  
Volumetric Analysis ◽  
Clinical Severity ◽  
Semantic Fluency ◽  
Brain Areas ◽  
Progressive Aphasia ◽  
Primary Progressive

Verbal fluency (VF) is an informative cognitive task. Lesion and functional imaging studies implicate distinct cerebral areas that support letter versus semantic fluency and the understanding of neural and cognitive mechanisms underlying task performance. Most lesion studies include chronic stroke patients. People with primary progressive aphasia (PPA) provide complementary evidence for lesion-deficit associations, as different brain areas are affected in stroke versus PPA. In the present study we sought to determine imaging, clinical and demographic correlates of VF in PPA. Thirty-five patients with PPA underwent an assessment with letter and category VF tasks, evaluation of clinical features and an MRI scan for volumetric analysis. We used stepwise regression models to determine which brain areas are associated with VF performance while acknowledging the independent contribution of clinical and demographic factors. Letter fluency was predominantly associated with language severity (R2 = 38%), and correlated with the volume of the left superior temporal regions (R2 = 12%) and the right dorsolateral prefrontal area (R2 = 5%). Semantic fluency was predominantly associated with dementia severity (R2 = 47%) and correlated with the volume of the left inferior temporal gyrus (R2 = 7%). No other variables were significantly associated with performance in the two VF tasks. We concluded that, independently of disease severity, letter fluency is significantly associated with the volume of frontal and temporal areas whereas semantic fluency is associated mainly with the volume of temporal areas. Furthermore, our findings indicated that clinical severity plays a critical role in explaining VF performance in PPA, compared to the other clinical and demographic factors.

scholarly journals Phonological Processing in Primary Progressive Aphasia

2016 ◽  
Vol 28 (2) ◽  
pp. 210-222 ◽  
Author(s):  
Maya L. Henry ◽  
Stephen M. Wilson ◽  
Miranda C. Babiak ◽  
Maria Luisa Mandelli ◽  
Pelagie M. Beeson ◽  
...  
Keyword(s):  
Language Processing ◽  
Phonological Processing ◽  
Critical Role ◽  
Dorsal Stream ◽  
Primary Progressive Aphasia ◽  
Binary Logistic Regression ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Dorsal Pathway ◽  
High Degree

Individuals with primary progressive aphasia (PPA) show selective breakdown in regions within the proposed dorsal (articulatory–phonological) and ventral (lexical–semantic) pathways involved in language processing. Phonological STM impairment, which has been attributed to selective damage to dorsal pathway structures, is considered to be a distinctive feature of the logopenic variant of PPA. By contrast, phonological abilities are considered to be relatively spared in the semantic variant and are largely unexplored in the nonfluent/agrammatic variant. Comprehensive assessment of phonological ability in the three variants of PPA has not been undertaken. We investigated phonological processing skills in a group of participants with PPA as well as healthy controls, with the goal of identifying whether patterns of performance support the dorsal versus ventral functional–anatomical framework and to discern whether phonological ability differs among PPA subtypes. We also explored the neural bases of phonological performance using voxel-based morphometry. Phonological performance was impaired in patients with damage to dorsal pathway structures (nonfluent/agrammatic and logopenic variants), with logopenic participants demonstrating particular difficulty on tasks involving nonwords. Binary logistic regression revealed that select phonological tasks predicted diagnostic group membership in the less fluent variants of PPA with a high degree of accuracy, particularly in conjunction with a motor speech measure. Brain–behavior correlations indicated a significant association between the integrity of gray matter in frontal and temporoparietal regions of the left hemisphere and phonological skill. Findings confirm the critical role of dorsal stream structures in phonological processing and demonstrate unique patterns of impaired phonological processing in logopenic and nonfluent/agrammatic variants of PPA.

scholarly journals P2-368: Anatomical correlates of primary progressive aphasia subtypes using SPGR 3D volumetric analysis

2010 ◽  
Vol 6 ◽  
pp. S423-S423 ◽  
Author(s):  
Hee Jin Kang ◽  
Yeojung Baik ◽  
Seung Ah Go ◽  
Jung Eun Kim ◽  
Kee Duk Park ◽  
...  
Keyword(s):  
Primary Progressive Aphasia ◽  
Volumetric Analysis ◽  
Progressive Aphasia ◽  
Primary Progressive

Considerations in Subtyping and Monitoring of Symptom Progression in Primary Progressive Aphasia

2014 ◽  
Vol 24 (4) ◽  
pp. 122-127
Author(s):  
Daisy Sapolsky ◽  
Kimiko Domoto-Reilly ◽  
Bradford C. Dickerson
Keyword(s):  
Critical Role ◽  
Primary Progressive Aphasia ◽  
Family Counseling ◽  
Language Abilities ◽  
Language Preservation ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Speech Language Pathologist ◽  
Initial Symptoms ◽  
Symptom Progression

A speech-language pathologist (SLP) may be one of the initial clinical providers for a patient with primary progressive aphasia (PPA), a group of neurodegenerative diseases involving the selective, progressive deterioration of speech and/or language abilities. While the three primary subtypes of PPA have distinct profiles of language preservation and impairment, the process of identifying the subtype can be challenging for many reasons, including subtle initial symptoms which can be difficult to detect on standard testing batteries. Early and accurate subtyping is important for clinical and research applications, which we will discuss here. The SLP plays a critical role in the initial subtyping process, as well as in helping to confirm that the course and presentation are consistent with a root diagnosis of PPA, as opposed to normal aging or other etiologies. The involvement of the SLP over time then focuses on monitoring symptom severity and progression, which is a particularly relevant issue for this population. The SLP can apply this information to inform treatment planning and patient/family counseling, and to assess potential benefits from interventions including conventional and novel speech therapies, and pharmaceutical treatments as they become available.

scholarly journals The left inferior frontal gyrus is causally involved in selective semantic retrieval: Evidence from tDCS in primary progressive aphasia

2020 ◽  
Author(s):  
Zeyi Wang ◽  
Bronte N Ficek ◽  
Kimberly T Webster ◽  
Chiadi U Onyike ◽  
John E Desmond ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Inferior Frontal Gyrus ◽  
Primary Progressive Aphasia ◽  
Superior Temporal Gyrus ◽  
Semantic Fluency ◽  
Semantic Retrieval ◽  
Left Inferior Frontal Gyrus ◽  
Progressive Aphasia ◽  
Temporal Lobes ◽  
Primary Progressive

Lesion and imaging studies have shown that the left inferior frontal gyrus (IFG) is involved in selective semantic retrieval of information from the temporal lobes. However, causal, i.e., interventional, evidence is sparse. In the present study we addressed this question by testing whether transcranial direct current stimulation (tDCS) over the left IFG in a group of individuals with primary progressive aphasia may improve semantic fluency, a task that relies to selective semantic retrieval. Semantic fluency improved significantly more in the tDCS vs. sham condition immediately post-treatment and improvement lasted up to 2 months. We further addressed the question of who will benefit most from such an intervention by testing possible demographic, clinical and functional connectivity variables that may predict the behavioral tDCS effect. We found that patients with stronger baseline functional connectivity between the subareas of the left IFG opercularis and triangularis, and between the middle temporal pole and superior temporal gyrus. were the most likely to benefit from tDCS over the left IFG. We thus provided causal evidence that the left IFG is the neural substrate of selective semantic retrieval and tDCS over the left IFG may improve semantic fluency in individuals with stronger baseline functional connectivity.

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