Progressive Compromise of Nouns and Action Verbs in Posterior Cortical Atrophy

Abstract

Processing of nouns and action verbs can be differentially compromised following lesions to posterior and anterior/motor brain regions, respectively. However, little is known about how these deficits progress in the course of neurodegeneration. To address this issue, we assessed productive lexical skills in a patient with posterior cortical atrophy (PCA) at two different stages of his pathology. On both occasions, he underwent a structural brain imaging protocol and completed semantic fluency tasks requiring retrieval of animals (nouns) and actions (verbs). Imaging results were compared with those of controls via voxel-based morphometry (VBM), whereas fluency performance was compared to age-matched norms through Crawford’s t-tests. In the first assessment, the patient exhibited atrophy of more posterior regions supporting multimodal semantics (medial temporal and lingual gyri), together with a selective deficit in noun fluency. Then, by the second assessment, the patient’s atrophy had progressed mainly toward fronto-motor regions (rolandic operculum, inferior and superior frontal gyri) and subcortical motor hubs (cerebellum, thalamus), and his fluency impairments had extended to action verbs. These results offer unprecedented evidence of the specificity of the pathways related to noun and action-verb impairments in the course of neurodegeneration, highlighting the latter’s critical dependence on damage to regions supporting motor functions, as opposed to multimodal semantic processes.

When it is not primary progressive aphasia: A scoping review of spoken language impairment in other neurodegenerative dementias

“…A language profile similar to that seen in people with logopenic aphasia was reported in three studies, 83,84,85 but with milder impact on comprehension and spontaneous speech 84 . One paper highlighted impaired fluency for nouns and verbs 86 . The remaining three studies identified additional impairments in comprehending words related to space and quantity 64,87,88 …”

Neurocognitive signatures of phonemic sequencing in expert backward speakers

“…Finally, due to practical limitations, behavioral and neuroimaging analyses were here performed on two separate samples, which precluded the exploration of correlations between performance and neural signatures. Although this methodology has yielded informative results regarding other aspects of language 121 , it would be desirable to circumvent such a limitation in new studies.…”

Heart–brain interactions during social and cognitive stress in hypertensive disease: A multidimensional approach

“…No significant differences were found ( F 1,42 = 0.00, p = .992, ηp 2 < 0.01) between patients ( M = 1,386.73, SD = 128.83) and controls ( M = 1,386.35, SD = 122.66). Statistical significance was set at p < .001 uncorrected, extent threshold = 30 voxels (de la Fuente et al., 2019; Steeb et al., 2018). A power estimation analysis confirmed the robustness of our results (Information S2).…”