Handwriting in Alzheimer's Disease

Area of Science:

• Neurology
• Gerontology
• Cognitive Science

Background:

• Agraphia, or writing impairment, is a common clinical manifestation in Alzheimer's disease (AD).
• Understanding the specific writing deficits in AD is crucial for early diagnosis and patient care.

Purpose of the Study:

• To compare handwriting kinematics between individuals with Alzheimer's disease (AD) and healthy controls.
• To identify and characterize the distinct writing deficits present in AD patients.

Main Methods:

• The study involved 23 AD patients and 34 healthy controls performing alphabetical and non-alphabetical writing tasks.
• Kinematographic analysis included measures like inversions per stroke (NIV), automation percentage, frequency, pressure, and velocity.
• Statistical analyses, including Spearman correlation and ROC analyses, were employed to evaluate the data.

Main Results:

• Alzheimer's disease patients demonstrated reduced automated movements (higher NIV), lower writing velocity, and decreased stroke frequency in both writing tasks.
• A significant correlation was found between overt writing errors and automaticity in AD patients.
• Kinematic measures showed excellent diagnostic potential for distinguishing AD from normal aging.

Conclusions:

• Writing disorders in Alzheimer's disease are complex and affect multiple processing levels.
• The observed deficits in motor program execution, characterized by slowness and poor automation, are not exclusive to alphabetical writing.