Beber Bárbara Costa, Kochhann Renata, Matias Bruna, Chaves Márcia Lorena Fagundes
Dementia Clinic, Neurology Service, Hospital de Clínicas de Porto Alegre (HCPA), RS, Brazil.
Graduate Program in Psychology, Human Cognition, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), RS, Brazil.
Dement Neuropsychol. 2016 Jul-Sep;10(3):227-231. doi: 10.1590/S1980-5764-2016DN1003009.
The Clock Drawing Test (CDT) is a brief cognitive screening tool for dementia. Several different presentation formats and scoring methods for the CDT are available in the literature.
In this study we aimed to compare performance on the free-drawn and "incomplete-copy" versions of the CDT using the same short scoring method in Mild Cognitive Impairment (MCI) and dementia patients, and healthy elderly participants.
90 participants (controlled for age, sex and education) subdivided into control group (n=20), MCI group (n=30) and dementia group (n=40) (Alzheimer's disease - AD=20; Vascular Dementia - VD=20) were recruited for this study. The participants performed the two CDT versions at different times and a blinded neuropsychologist scored the CDTs using the same scoring system.
The scores on the free-drawn version were significantly lower than the incomplete-copy version for all groups. The dementia group had significantly lower scores on the incomplete-copy version of the CDT than the control group. MCI patients did not differ significantly from the dementia or control groups. Performance on the free-drawn copy differed significantly among all groups.
The free-drawn CDT version is more cognitively demanding and sensitive for detecting mild/early cognitive impairment. Further evaluation of the diagnostic value (accuracy) of the free-drawn CDT in Brazilian MCI patients is needed.
画钟测试（CDT）是一种用于痴呆症的简短认知筛查工具。文献中提供了几种不同的CDT呈现形式和评分方法。
在本研究中，我们旨在使用相同的简短评分方法，比较轻度认知障碍（MCI）患者、痴呆症患者和健康老年参与者在自由绘制版和“不完全临摹”版CDT上的表现。
本研究招募了90名参与者（按年龄、性别和教育程度进行匹配），分为对照组（n = 20）、MCI组（n = 30）和痴呆症组（n = 40）（阿尔茨海默病 - AD = 20；血管性痴呆 - VD = 20）。参与者在不同时间进行两个版本的CDT测试，由一位不知情的神经心理学家使用相同的评分系统对CDT进行评分。
所有组在自由绘制版上的得分均显著低于不完全临摹版。痴呆症组在CDT不完全临摹版上的得分显著低于对照组。MCI患者与痴呆症组或对照组之间无显著差异。所有组在自由绘制版上的表现存在显著差异。
自由绘制版CDT对认知要求更高，对检测轻度/早期认知障碍更敏感。需要进一步评估自由绘制版CDT在巴西MCI患者中的诊断价值（准确性）。
