Rinsho Shinkeigaku (Clinical Neurology)

Original Article

Quantitative and qualitative analyses for characteristics of the clock drawing in Alzheimer's disease

Yoko Konagaya, M.D.1), Masaaki Konagaya, M.D.2), Tomoyuki Watanabe, Ph.D.1)3) and Yukihiko Washimi, M.D.4)

1)Division of Research, Obu Dementia Care and Training Center
2)National Hospital Organization, Suzuka Hospital
3)Faculty of Psychological and Physical Science, Aichi Gakuin Unversity
4)Department of Neurology, National Center for Geriatrics and Gerontology

We analyzed the results of the clock drawing test (CDT) in patients with Alzheimer's disease (AD) by quantitative and qualitative methods to evaluate its significance for cognitive function screening. We administered the CDT and mini-mental state examination (MMSE) to a total of 156 AD patients, and CDT performance was scored quantitatively in accordance with the method by Freedman, while the CDT error types were qualitatively classified by Rouleau's method. We divided AD patients into three groups by their MMSE total score (A: 23 ≤, B: 18∼22, C: ≤ 17). The mean total scores of CDT and MMSE in AD were 11.5 ± 3.4 and 19.8 ± 4.7, respectively, and the total CDT scores showed significant positive correlation with the total MMSE scores (r = 0.450). Fewer than 80% of subjects drew the clock correctly for 8 out of 15 sub-items, and fewer were able to correctly draw clock hands than could correctly draw numbers, contour or a center. In analysis of CDT qualitative error types, the most common error types were spatial and/or planning deficit (SPD) (28.2%), and conceptual deficit (CD) (23.7%), which suggested visuospatial impairments and semantic impairments play essential roles in AD patients' poor clock drawings. The frequency of CD and SPD error types significantly increased as severity of cognitive function worsened (p < 0.001, p < 0.05, respectively), and those of stimulus-bound response and perseveration had tendency to increase as severity of cognitive function. The present study suggests that CDT is a useful screening method not only for the impairment of cognitive function and the severity of cognitive dysfunction, but also for identification of specific cognitive function impairments in AD patients.
Full Text of this Article in Japanese PDF (1540K)

(CLINICA NEUROL, 54: 109|115, 2014)
key words: Alzheimer's disease, clock drawing test, quantitative analysis, qualitative analysis

(Received: 21-Jan-13)