Clock drawing as an assessment tool for dementia

Abstract

Clock drawing has recently been shown to lie useful in differentiating Alzieimer's disease patients from normal controls. Our procedure for clock drawing differed from other published reports in that a copy condition was employed and patients were asked to set clock hands to read "ten after eleven". We found both clock drawing procedures to be correlated with tests related to executive and visuospatial functioning. In both conditions, nondemented controls performed significantly better than demented patients. In the command condition there was no difference between Alzheimer patients and patients with cerebrovascular dementia. In the copy condition, patients with cerebrovascular dementia performed significantly worse than Alzheimer patients. The inclusion of a copy condition appears to greatly expand the utility of this test. Although our scoring system did not differentiate between various dementing disorders in the command condition, if clock drawing is used as a screening instrument, lack of improvement in the copy condition in comparison to the command condition may be a sign of a vascular involvement.

Limitations in differentiating vascular dementia from Alzheimer's disease with brief cognitive tests

“…By contrast, we found that CLOX 1 did not discriminate AD from VaD, although VaD patients performed worse in the CLOX 2 task. This finding can be explained by greater executive dysfunction and visuo-constructive impairment in VaD compared to AD, as already observed by other investigators 22,23 . Libon et al 23 showed that only AD patients' performance in CLOX 1 improved in relation to CLOX 2 when compared to VaD associated with SVaD.…”

“…This finding can be explained by greater executive dysfunction and visuo-constructive impairment in VaD compared to AD, as already observed by other investigators 22,23 . Libon et al 23 showed that only AD patients' performance in CLOX 1 improved in relation to CLOX 2 when compared to VaD associated with SVaD. These authors concluded that the copy condition may be sensitive to executive dysfunction and the impaired performance of AD patients in CLOX 1 might be explained by deficient semantic knowledge.…”

Error detection and correction patterns in dementia: A breakdown of error monitoring processes and their neuropsychological correlates

“…Ten possible errors were scored on each trial. Cosentino et al, 2004;Libon et al, 1993Libon et al, , 1996 Language Boston Naming Test The dependent variable is the number of pictures correctly named.…”

Subcortical vascular dementia

“…This test appears to be diagnostically sensitive test for subcortical VaD. 23,24 Data from our laboratory show a high correlation between total clock-drawing errors and copy of the Rey Complex Figure 24,25 (−0.570 to −0.649, unpublished data).…”

“…Previous research has shown that total errors summed across the command and copy conditions are highly correlated with performance on tests of executive control and visuospatial ability. [21][22][23] Therefore, the dependent variable derived from this test was the total number of errors summed across the command and copy test conditions. This test appears to be diagnostically sensitive test for subcortical VaD.…”