Phonological Errors in Posterior Cortical Atrophy.

Area of Science:

• Neurology
• Neuroscience
• Cognitive Science

Background:

• Posterior cortical atrophy (PCA) is an atypical Alzheimer's disease (AD) variant presenting with visuospatial deficits.
• PCA shares posterior brain atrophy patterns with logopenic variant primary progressive aphasia (lvPPA), an AD variant characterized by language impairments.
• While language issues are noted in PCA, the prevalence of phonological errors remains unclear.

Purpose of the Study:

• To compare the frequency and severity of phonological errors in PCA versus lvPPA.
• To identify neuroanatomical correlates of phonological errors and language deficits in PCA.

Main Methods:

• Phonological errors were assessed using the Boston Naming Test and Western Aphasia Battery repetition subtest in 27 PCA and 27 age/disease-matched lvPPA patients.
• Spearman correlations were used to link phonological error counts and language test scores with regional gray matter volumes.

Main Results:

• Phonological errors were present in 55% of PCA patients and 70% of lvPPA patients, with lvPPA showing more errors.
• In PCA, phonological errors correlated with reduced gray matter volume in the left inferior parietal and lateral temporal lobes.
• Naming and fluency deficits in PCA were associated with decreased left lateral temporal lobe volume.

Conclusions:

• Phonological errors are common in PCA but less prevalent and severe than in lvPPA.
• These errors in PCA are associated with left temporoparietal cortex involvement.
• The findings underscore the diverse clinical spectrum of AD and the overlap between PCA and lvPPA syndromes.