Characteristics of clock drawing test (CDT) errors by the dementia type: quantitative and qualitative analyses

Area of Science:

• Neuroscience
• Neurology
• Psychology

Background:

• The Clock Drawing Test (CDT) is a common tool for cognitive assessment.
• Differentiating between types of dementia, such as Alzheimer disease (AD), vascular dementia (VaD), and Parkinson's disease with dementia (PDD), is crucial for effective treatment.

Purpose of the Study:

• To characterize errors on the Clock Drawing Test (CDT).
• To evaluate the utility of CDT errors in the early diagnosis and differentiation of dementia subtypes.

Main Methods:

• Performance on four CDT versions was evaluated in patients with AD, VaD, and PDD.
• Qualitative and quantitative analyses of specific error types were conducted.

Main Results:

• Patients with vascular dementia (VaD) and Parkinson's disease with dementia (PDD) exhibited more stimulus-bound responses.
• Patients with Alzheimer disease (AD) made significantly more conceptual deficit (CD) errors.
• Conceptual deficit (CD) errors correlated with dementia severity and were detectable in early and mild stages.

Conclusions:

• Analysis of CDT errors can aid in the early differential diagnosis of dementia.
• Specific error patterns on the CDT may help distinguish between AD, VaD, and PDD.