Writing errors in primary progressive aphasia.

Area of Science:

• Neurology
• Linguistics
• Cognitive Science

Background:

• Peripheral writing errors (e.g., spelling mistakes) are occasionally noted in primary progressive aphasia (PPA).
• The potential of these errors as a marker for parkinsonism in specific PPA subtypes remains underexplored.

Purpose of the Study:

• To investigate if peripheral errors characterize the writing disorder in PPA subtypes associated with parkinsonian signs (PSs).
• To determine the clinical relevance of peripheral errors in PPA patients with and without PSs.

Main Methods:

• Comparison of central and peripheral writing error proportions in PPA subgroups with and without PSs.
• Analysis of word and pseudoword writing tasks.
• Correlation analysis with cognitive measures and the Unified Parkinson's Disease Rating Scale (UPDRS).

Main Results:

• Central errors predominated over peripheral errors in PPA subgroups without PSs.
• A higher number of peripheral errors correlated significantly with the presence of PSs.
• Both error types correlated with cognitive ability measures, but not UPDRS scores.

Conclusions:

• Peripheral errors appear to emerge when parkinsonian signs are associated with PPA.
• These errors may reflect a decline in cognitive control over movement, potentially involving the right hemisphere.
• Peripheral errors hold clinical significance as potential markers for specific PPA subtypes and individual patient profiling.