Background: Although some studies suggest that writing difficulties may be one of the early
symptoms of Alzheimer's disease (AD), they have been scarcely studied compared to oral language. Particularly
noteworthy is the paucity of longitudinal studies that enable the observation of writing impairment
as cognitive decline progresses.
Objective: The aim of this study was to examine the characteristics of writing in patients with AD and to
monitor the deterioration of their performance over a follow-up period.
Methods: Sixty-four participants (half with AD and half healthy elderly) were compared in a word and
pseudo-word dictation task. Patients were evaluated every 6 months over a 2.5 year follow-up period.
Results: The evolution of patient performance and error profile shows a typical pattern of deterioration,
with early damage to the lexical pathway, which later extends to the phonological pathway and eventually
affects peripheral processes.
Conclusion: These results confirm the presence of writing difficulties from the early stages of AD, supporting
the value of this task for early diagnosis. Furthermore, it allows us to explain the contradictory
data obtained in previous investigations.