Qualitative clock-drawing errors across dementia etiologies and mild cognitive impairment: a clinically interpretable six-class framework
5 affiliations
- 1Department of Neurology, Medical College Kolkata, Kolkata, India
- 2Department of Neurology, 12 de Octubre University Hospital, Madrid, Spain
- 3Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), Madrid, Spain
- 4Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- 5Department of Medicine, Faculty of Medicine, Complutense University of Madrid, Madrid, Spain
Abstract
Objective: To characterize qualitative Clock Drawing Test (CDT) error profiles across dementia etiologies and mild cognitive impairment (MCI), and to propose a clinically interpretable six-class framework.
Methods: In a hospital-based study in Kolkata, India, consecutive adults with cognitive impairment completed a free-drawn “ten past ten” CDT. Errors were coded using classical qualitative categories and clock components (face, numbers, hands), then collapsed into six classes: conceptual, stimulus-bound/perseveration, spatial, planning, number-related, and graphic-conceptual. For nonexclusive domains, omnibus Pearson χ² tests summarized error distributions across diagnoses; Cramér’s V quantified effect size.
Results: Participants included Alzheimer’s disease (AD; n = 36), vascular dementia (VaD; n = 16), behavioral variant frontotemporal dementia (bvFTD; n = 9), MCI (n = 19), and other conditions (n = 22). Although 50.0% drew a normal clock face, only 11.8% achieved perfect numbering and 12.7% set the hands correctly. Conceptual errors were most frequent (70.6%), followed by spatial errors (47.1%); neglect and counterclockwise numbering were rare (3.9% each). Error distributions differed by diagnosis for face, numbers, and hands (all p < 0.001; V = 0.4–0.5). The six-class scheme retained a significant distributional association with diagnosis (χ² = 43.365, p = 0.002; V = 0.3): bvFTD showed prominent conceptual and graphic-conceptual failures, AD combined conceptual and spatial errors, MCI emphasized spatial and number-related errors, and VaD was heterogeneous.
Conclusions: Qualitative CDT profiles vary meaningfully across cognitive disorders. This concise six-class framework captures clinically salient patterns, especially in severely degraded drawings, and may complement brief memory screening and digital CDT metrics.
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BibTeX
@article{banik2026qualitative,
title = {{Qualitative clock-drawing errors across dementia etiologies and mild cognitive impairment: a clinically interpretable six-class framework}},
author = {Ankur Banik and Sandip Pal and Asutosh Pal and Moukoli Pal and Indranil Dutta and Dilip Roy and Amrit Chattopadhyay and Julian Benito-Leon},
journal = {CNS Spectrums},
year = {2026},
month = jun,
doi = {10.1017/s1092852926101072},
url = {https://doi.org/10.1017/s1092852926101072},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Qualitative clock-drawing errors across dementia etiologies and mild cognitive impairment: a clinically interpretable six-class framework
AU - Ankur Banik
AU - Sandip Pal
AU - Asutosh Pal
AU - Moukoli Pal
AU - Indranil Dutta
AU - Dilip Roy
AU - Amrit Chattopadhyay
AU - Julian Benito-Leon
PY - 2026
DA - 2026/06/18
JO - CNS Spectrums
DO - 10.1017/s1092852926101072
UR - https://doi.org/10.1017/s1092852926101072
AB - Objective: To characterize qualitative Clock Drawing Test (CDT) error profiles across dementia etiologies and mild cognitive impairment (MCI), and to propose a clinically interpretable six-class framework. Methods: In a hospital-based study in Kolkata, India, consecutive adults with cognitive impairment completed a free-drawn “ten past ten” CDT. Errors were coded using classical qualitative categories and clock components (face, numbers, hands), then collapsed into six classes: conceptual, stimulus-bound/perseveration, spatial, planning, number-related, and graphic-conceptual. For nonexclusive domains, omnibus Pearson χ² tests summarized error distributions across diagnoses; Cramér’s V quantified effect size. Results: Participants included Alzheimer’s disease (AD; n = 36), vascular dementia (VaD; n = 16), behavioral variant frontotemporal dementia (bvFTD; n = 9), MCI (n = 19), and other conditions (n = 22). Although 50.0% drew a normal clock face, only 11.8% achieved perfect numbering and 12.7% set the hands correctly. Conceptual errors were most frequent (70.6%), followed by spatial errors (47.1%); neglect and counterclockwise numbering were rare (3.9% each). Error distributions differed by diagnosis for face, numbers, and hands (all p < 0.001; V = 0.4–0.5). The six-class scheme retained a significant distributional association with diagnosis (χ² = 43.365, p = 0.002; V = 0.3): bvFTD showed prominent conceptual and graphic-conceptual failures, AD combined conceptual and spatial errors, MCI emphasized spatial and number-related errors, and VaD was heterogeneous. Conclusions: Qualitative CDT profiles vary meaningfully across cognitive disorders. This concise six-class framework captures clinically salient patterns, especially in severely degraded drawings, and may complement brief memory screening and digital CDT metrics.
SN - 1092-8529
SN - 2165-6509
ER -