Primary and Secondary Progressive Aphasia in Posterior Cortical Atrophy

Abstract

Background: Posterior cortical atrophy (PCA) is a clinico-radiological syndrome characterized by a progressive decline in visuospatial/visuoperceptual processing. PCA is accompanied by the impairment of other cognitive functions, including language abilities.

Methods: The present study focused on three patients presenting with language complaints and a clinical profile that was compatible with PCA. In addition to neurological and neuroimaging examinations, they were assessed with comprehensive batteries of neuropsychological and neurolinguistic tests.

Results: The general medical profile of the three patients is consistent with PCA, although they presented with confounding factors, making diagnosis less clear. The cognitive profile of the three patients was marked by Balint and Gerstmann's syndromes as well as impairments affecting executive functions, short-term and working memory, visuospatial and visuoperceptual abilities, and sensorimotor execution abilities. Their language ability was characterized by word-finding difficulties and impairments of sentence comprehension, sentence repetition, verbal fluency, narrative speech, reading, and writing.

Conclusions: This study confirmed that PCA is marked by visuospatial and visuoperceptual deficits and reported evidence of primary and secondary language impairments in the three patients. The similarities of some of their language impairments with those found in the logopenic variant of primary progressive aphasia is discussed from neurolinguistic and neuroanatomical points of view.

Keywords: Alzheimer’s disease; differential diagnosis; language impairment; logopenic variant of primary progressive aphasia; posterior cortical atrophy.

Figure 1

FDG-PET Scan of P2 and P3. (A) P2. Reconstructed slices showing hypometabolism of the left polymodal associative areas, especially the parieto-occipital regions, as well as asymmetry (left > right) of the primary visual areas. (B) P2. Statistical analysis of metabolism distribution as compared to marched normal database showing areas of hypometabolism in the left hemisphere, including in the left posterior temporal region (image circled in red). (C) P3. Hypometabolism of the left posterior parietal region.