scholarly journals Neural dynamics of semantic categorization in semantic variant of Primary Progressive Aphasia

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Valentina Borghesani ◽  
Corby L Dale ◽  
Sladjana Lukic ◽  
Leighton BN Hinkley ◽  
Michael Lauricella ◽  
...  
Keyword(s):  
Primary Progressive Aphasia ◽  
Superior Temporal Gyrus ◽  
Semantic Knowledge ◽  
Clinical Syndrome ◽  
Perceptual Processing ◽  
Behavioral Performance ◽  
Semantic Representations ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Semantic Variant

Semantic representations are processed along a posterior-to-anterior gradient reflecting a shift from perceptual (e.g., it has eight legs) to conceptual (e.g., venomous spiders are rare) information. One critical region is the anterior temporal lobe (ATL): patients with semantic variant primary progressive aphasia (svPPA), a clinical syndrome associated with ATL neurodegeneration, manifest a deep loss of semantic knowledge. We test the hypothesis that svPPA patients perform semantic tasks by over-recruiting areas implicated in perceptual processing. We compared MEG recordings of svPPA patients and healthy controls during a categorization task. While behavioral performance did not differ, svPPA patients showed indications of greater activation over bilateral occipital cortices and superior temporal gyrus, and inconsistent engagement of frontal regions. These findings suggest a pervasive reorganization of brain networks in response to ATL neurodegeneration: the loss of this critical hub leads to a dysregulated (semantic) control system, and defective semantic representations are seemingly compensated via enhanced perceptual processing.

scholarly journals Neural dynamics of semantic categorization in semantic variant of Primary Progressive Aphasia

2020 ◽  
Author(s):  
V. Borghesani ◽  
C. L. Dale ◽  
S. Lukic ◽  
L. B. N. Hinkley ◽  
M. Lauricella ◽  
...  
Keyword(s):  
Primary Progressive Aphasia ◽  
Superior Temporal Gyrus ◽  
Semantic Knowledge ◽  
Clinical Syndrome ◽  
Perceptual Processing ◽  
Semantic Representations ◽  
Semantic Categorization ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Semantic Variant

AbstractAwake humans constantly extract conceptual information from a flow of perceptual inputs. Category membership (e.g., is it an animate or inanimate thing?) is a critical semantic feature used to determine the appropriate response to a stimulus. Semantic representations are thought to be processed along a posterior-to-anterior gradient reflecting a shift from perceptual (e.g., it has eight legs) to conceptual (e.g., venomous spiders are rare) information. One critical region is the anterior temporal lobe (ATL): patients with semantic variant primary progressive aphasia (svPPA), a clinical syndrome associated with ATL neurodegeneration, manifest a deep loss of semantic knowledge.Here, we test the hypothesis that svPPA patients, in the absence of an intact ATL, perform semantic tasks by over-recruiting areas implicated in perceptual processing. We acquired MEG recordings of 18 svPPA patients and 18 healthy controls during a semantic categorization task. While behavioral performance did not differ, svPPA patients showed greater activation over bilateral occipital cortices and superior temporal gyrus, and inconsistent engagement of frontal regions.These findings indicate a pervasive reorganization of brain networks in response to ATL neurodegeneration: the loss of this critical hub leads to a dysregulated (semantic) control system, and defective semantic representations are compensated via enhanced perceptual processing.

scholarly journals Profile of linguistic and cognitive deficits in persons with a semantic variant of a primary progressive aphasia

2020 ◽  
Vol 54 (3) ◽  
pp. 113-119
Author(s):  
Lana Jerkić ◽  
Dragan Pavlović ◽  
Mile Vuković ◽  
Jelena Todorović ◽  
Mirna Zelić
Keyword(s):  
Specific Treatment ◽  
Primary Progressive Aphasia ◽  
Semantic Knowledge ◽  
Cognitive Changes ◽  
Progressive Aphasia ◽  
Progressive Deterioration ◽  
Primary Progressive ◽  
Language Functions ◽  
Semantic Variant ◽  
Speech And Language Disorders

Primary progressive aphasia (PPA) includes a group of neurodegenerative disorders that are characterized by progressive deterioration of language functions, while other cognitive functions, at least at the onset of the disease, are relatively spared. There are three basic subtypes of PPA: the nonfluent progressive aphasia (nvPPA), the semantic variant of a primary progressive aphasia (svPPA), and the logopenic progressive aphasia (lvPPA). The semantic variant of a PPA can also be found in the literature under the term of semantic dementia. It is clinically manifested by progressive deterioration of semantic knowledge, fluent aphasia, impaired naming and comprehension, prosopagnosia and surface dyslexia and dysgraphia (in languages with irregular orthography). As the disease progresses, other cognitive changes can be observed. The main cause of the disorder is progressive bilateral atrophy of the anterior temporal lobes, which is more manifested in the left hemisphere. The literature is modest in terms of the use of specific treatment methods in the rehabilitation of these patients. Since speech and language disorders are the most conspicuous symptom, at least at the beginning of the disease, the role of speech therapists in the assessment and restitution of speechlanguage and communication skills is also indisputable.

Errorless Learning Therapy in Semantic Variant of Primary Progressive Aphasia

2021 ◽  
Vol 79 (1) ◽  
pp. 415-422
Author(s):  
Núria Montagut ◽  
Sergi Borrego-Écija ◽  
Magdalena Castellví ◽  
Immaculada Rico ◽  
Ramón Reñé ◽  
...  
Keyword(s):  
Speech Therapy ◽  
Primary Progressive Aphasia ◽  
Semantic Knowledge ◽  
Errorless Learning ◽  
Short Term ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Semantic Variant ◽  
Naming Tasks

Background: The semantic variant of primary progressive aphasia (svPPA) is characterized by a progressive loss of semantic knowledge impairing the ability to name and to recognize the meaning of words. Objective: We aimed to evaluate the immediate and short-term effect of errorless learning speech therapy on the naming and recognition of commonly used words in patients with svPPA. Methods: Eight participants diagnosed with svPPA received 16 sessions of intensive errorless learning speech therapy. Naming and word comprehension tasks were evaluated at baseline, immediately postintervention, and at follow-up after 1, 3, and 6 months. These evaluations were performed using two item sets (a trained list and an untrained list). Results: In the naming tasks, patients showed a significant improvement in trained items immediately after the intervention, but that improvement decayed progressively when therapy ended. No improvements were found either in trained comprehension or in untrained tasks. Conclusion: Errorless learning therapy could improve naming ability in patients with svPPA. This effect may be due to the relative preservation of episodic memory, but the benefit is not maintained over time, presumably because there is no consolidation.

scholarly journals Semantic Variant Primary Progressive Aphasia: Practical Recommendations for Treatment from 20 Years of Behavioural Research

2021 ◽  
Vol 11 (12) ◽  
pp. 1552
Author(s):  
Aida Suárez-González ◽  
Sharon A. Savage ◽  
Nathalie Bier ◽  
Maya L. Henry ◽  
Regina Jokel ◽  
...  
Keyword(s):  
Best Practice ◽  
Current Knowledge ◽  
Primary Progressive Aphasia ◽  
Memory Systems ◽  
Semantic Knowledge ◽  
Future Research ◽  
Long Term Memory ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Semantic Variant

People with semantic variant primary progressive aphasia (svPPA) present with a characteristic progressive breakdown of semantic knowledge. There are currently no pharmacological interventions to cure or slow svPPA, but promising behavioural approaches are increasingly reported. This article offers an overview of the last two decades of research into interventions to support language in people with svPPA including recommendations for clinical practice and future research based on the best available evidence. We offer a lay summary in English, Spanish and French for education and dissemination purposes. This paper discusses the implications of right- versus left-predominant atrophy in svPPA, which naming therapies offer the best outcomes and how to capitalise on preserved long-term memory systems. Current knowledge regarding the maintenance and generalisation of language therapy gains is described in detail along with the development of compensatory approaches and educational and support group programmes. It is concluded that there is evidence to support an integrative framework of treatment and care as best practice for svPPA. Such an approach should combine rehabilitation interventions addressing the language impairment, compensatory approaches to support activities of daily living and provision of education and support within the context of dementia.

Ethical and Practical Challenges of the Communication and Behavioral Manifestations of Primary Progressive Aphasia

2020 ◽  
Vol 41 (03) ◽  
pp. 249-256
Author(s):  
Donna C. Tippett ◽  
Argye E. Hillis
Keyword(s):  
Social Interactions ◽  
Primary Progressive Aphasia ◽  
Treatment Decisions ◽  
Clinical Syndrome ◽  
Self Determination ◽  
Family Education ◽  
Treatment Interventions ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Semantic Variant

AbstractThe communication and behavioral manifestations of primary progressive aphasia (PPA) present ethical and practical challenges for individuals with this clinical syndrome as well as for individuals who are involved closely in their care. In this article, cases representing all three PPA variants (logopenic variant, nonfluent agrammatic, semantic variant) are presented to illustrate commonly encountered situations in which self-determination is at risk in decisions about housing, driving, social interactions, finances, and treatment interventions. Potential approaches, including patient/family education, implementation of safeguards, redirection to meaningful activities, and protections against vulnerability in treatment decisions, are described to preserve autonomy in patients with this neurodegenerative clinical syndrome.

scholarly journals [18F]AV-1451 binding in vivo mirrors the expected distribution of TDP-43 pathology in the semantic variant of primary progressive aphasia

2017 ◽  
Vol 89 (10) ◽  
pp. 1032-1037 ◽  
Author(s):  
W R Bevan-Jones ◽  
Thomas E Cope ◽  
P Simon Jones ◽  
Luca Passamonti ◽  
Young T Hong ◽  
...  
Keyword(s):  
Frontotemporal Lobar Degeneration ◽  
Primary Progressive Aphasia ◽  
Hierarchical Cluster ◽  
Clinical Syndrome ◽  
Semantic Dementia ◽  
Binding Potential ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Semantic Variant

IntroductionSemantic dementia, including the semantic variant of primary progressive aphasia (svPPA), is strongly associated with TAR-DNA binding protein 43 (TDP-43) type C pathology. It provides a useful model in which to test the specificity of in vivo binding of the putative tau ligand [18F]AV-1451, which is elevated in frontotemporal lobar degeneration tauopathies.Methods and resultsSeven patients (five with svPPA and two with ‘right’ semantic dementia) and 12 healthy controls underwent positron emission tomography brain imaging with [18F]AV-1451. Two independent preprocessing methods were used. For both methods, all patients had clearly elevated binding potential (BPND (non-displaceable binding potential)) in temporal lobes, lateralising according to their clinical syndrome and evident in raw images. Region of interest analyses confirmed that BPND was significantly increased in temporal regions, insula and fusiform gyrus, consistent with those areas known to be most affected in semantic dementia. Hierarchical cluster analysis, based on the distribution of [18F]AV-1451 binding potential, separated semantic dementia from controls with 86% sensitivity and 100% specificity.Conclusions[18F]AV-1451 binds in vivo regions that are likely to contain TDP-43 and not significant tau pathology. While this suggests a non-tau target for [18F]AV-1451, the pathological regions in semantic dementia do not normally contain significant levels of recently proposed ‘off target’ binding sites for [18F]AV-1451, such as neuronal monoamine oxidase or neuromelanin. Postmortem and longitudinal data will be useful to assess the utility of [18F]AV-1451 to differentiate and track different types of frontotemporal lobar degeneration.

scholarly journals When affect overlaps with concept: emotion recognition in semantic variant of primary progressive aphasia

Brain ◽  
2020 ◽  
Author(s):  
Maxime Bertoux ◽  
Harmony Duclos ◽  
Marie Caillaud ◽  
Shailendra Segobin ◽  
Catherine Merck ◽  
...  
Keyword(s):  
Emotion Recognition ◽  
Conceptual Knowledge ◽  
Grey Matter ◽  
Primary Progressive Aphasia ◽  
Semantic Knowledge ◽  
Facial Emotion Recognition ◽  
Facial Emotion ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Semantic Variant

Abstract The most recent theories of emotions have postulated that their expression and recognition depend on acquired conceptual knowledge. In other words, the conceptual knowledge derived from prior experiences guide our ability to make sense of such emotions. However, clear evidence is still lacking to contradict more traditional theories, considering emotions as innate, distinct and universal physiological states. In addition, whether valence processing (i.e. recognition of the pleasant/unpleasant character of emotions) also relies on semantic knowledge is yet to be determined. To investigate the contribution of semantic knowledge to facial emotion recognition and valence processing, we conducted a behavioural and neuroimaging study in 20 controls and 16 patients with the semantic variant of primary progressive aphasia, a neurodegenerative disease that is prototypical of semantic memory impairment, and in which an emotion recognition deficit has already been described. We assessed participants’ knowledge of emotion concepts and recognition of 10 basic (e.g. anger) or self-conscious (e.g. embarrassment) facial emotional expressions presented both statically (images) and dynamically (videos). All participants also underwent a brain MRI. Group comparisons revealed deficits in both emotion concept knowledge and emotion recognition in patients, independently of type of emotion and presentation. These measures were significantly correlated with each other in patients and with semantic fluency in patients and controls. Neuroimaging analyses showed that both emotion recognition and emotion conceptual knowledge were correlated with reduced grey matter density in similar areas within frontal ventral, temporal, insular and striatal regions, together with white fibre degeneration in tracts connecting frontal regions with each other as well as with temporal regions. We then performed a qualitative analysis of responses made during the facial emotion recognition task, by delineating valence errors (when one emotion was mistaken for another of a different valence), from other errors made during the emotion recognition test. We found that patients made more valence errors. The number of valence errors correlated with emotion conceptual knowledge as well as with reduced grey matter volume in brain regions already retrieved to correlate with this score. Specificity analyses allowed us to conclude that this cognitive relationship and anatomical overlap were not mediated by a general effect of disease severity. Our findings suggest that semantic knowledge guides the recognition of emotions and is also involved in valence processing. Our study supports a constructionist view of emotion recognition and valence processing, and could help to refine current theories on the interweaving of semantic knowledge and emotion processing.

scholarly journals Primary Progressive Aphasia: Toward a Pathophysiological Synthesis

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Justina Ruksenaite ◽  
Anna Volkmer ◽  
Jessica Jiang ◽  
Jeremy CS Johnson ◽  
Charles R Marshall ◽  
...  
Keyword(s):  
Care Management ◽  
Primary Progressive Aphasia ◽  
Disease Stage ◽  
Major Step ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
New Findings ◽  
Critical Issues ◽  
Semantic Variant ◽  
Auditory Impairments

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. Summary 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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