Background: The aim of this study was to identify the neural correlates of each component of the clock drawing test (CDT) in drug-naïve patients with Alzheimer's disease (AD) using single photon emission computed tomography.

Methods: The participants were 95 drug-naïve patients with AD. The Rouleau CDT was used to score the clock drawings. The score for the Rouleau CDT (R total) is separated into three components: the scores for the clock face (R1), the numbers (R2), and the hands (R3). A multiple regression analysis was performed to examine the relationship of each score (i.e. R total, R1, R2, and R3) with regional cerebral blood flow (rCBF). Age, gender, and education were included as covariates. The statistical threshold was set to a family-wise error (FWE)-corrected p value of 0.05 at the voxel level.

Results: The R total score was positively correlated with rCBF in the bilateral parietal and posterior temporal lobes and the right middle frontal gyrus. R1 was not significantly positively correlated with rCBF, R2 was significantly positively correlated with rCBF in the right posterior temporal lobe and the left posterior middle temporal lobe, and R3 was significantly positively correlated with rCBF in the bilateral parietal lobes, the right posterior temporal lobe, the right middle frontal gyrus, and the right occipital lobe.

Conclusions: Various brain regions were associated with each component of the CDT. These results suggest that an assessment of these components is useful for the detection of localization of brain damage.

Background: There is a strong demand for screening instruments for mild cognitive impairment (MCI), as a pre-stage of dementia. The clock drawing test (CDT) is widely used to screen for dementia, but the utility in screening for MCI remains uncertain. In particular, it is still questionable which scoring system is the best in order to screen for MCI. We therefore aimed to compare the utility of different CDT scoring systems for screening for MCI.

Methods: In a sample of 428 subjects of the Leipzig Longitudinal Study of the Aged (LEILA 75+) study, CDT scores of different scoring systems were compared between subjects with and without MCI. Comparison of receiver operating characteristic (ROC; area under the curve, sensitivity, specificity) was performed and inter-rater reliability was calculated.

Results: The CDT scores differed significantly between MCI and non-MCI subjects according to all scoring systems applied. However, ROC of the CDT scores was not adequate.

Conclusions: None of the present CDT scoring systems has sufficient utility to screen reliably for MCI. The clinical value of the CDT could be improved by using semi-quantitative scoring, having a wider score range and focusing on specific details of the clock (e.g. the hands and numbers).

Background: Although the Clock Drawing Test (CDT) is the second most used test in the world for the screening of dementia, there is still debate over its sensitivity, specificity, application and interpretation in dementia diagnosis. This study has three main aims: to evaluate the sensitivity and specificity of the CDT in a sample composed of older adults with Alzheimer's disease (AD) and normal controls; to compare CDT accuracy to the that of the Mini-mental State Examination (MMSE) and the Cambridge Cognitive Examination (CAMCOG); and to test whether the association of the MMSE with the CDT leads to higher or comparable accuracy as that reported for the CAMCOG.

Methods: Cross-sectional assessment was carried out for 121 AD and 99 elderly controls with heterogeneous educational levels from a geriatric outpatient clinic who completed the Cambridge Examination for Mental Disorder of the Elderly (CAMDEX). The CDT was evaluated according to the Shulman, Mendez and Sunderland scales.

Results: The CDT showed high sensitivity and specificity. There were significant correlations between the CDT and the MMSE (0.700–0.730; p < 0.001) and between the CDT and the CAMCOG (0.753–0.779; p < 0.001). The combination of the CDT with the MMSE improved sensitivity and specificity (SE = 89.2–90%; SP = 71.7–79.8%). Subgroup analysis indicated that for elderly people with lower education, sensitivity and specificity were both adequate and high.

Conclusions: The CDT is a robust screening test when compared with the MMSE or the CAMCOG, independent of the scale used for its interpretation. The combination with the MMSE improves its performance significantly, becoming equivalent to the CAMCOG.

Background: The clock drawing test (CDT) is a common and widely used cognitive screening instrument for the diagnosis of dementia. However, it has remained unclear whether it is a suitable method to identify mild cognitive impairment (MCI). The aim of this paper is to review systematically the studies concerning the utility of the CDT in diagnosing MCI.

Method: A systematic literature search was conducted. All studies dealing with utility of CDT in diagnosing MCI regardless of the applied CDT scoring system and MCI concept were selected.

Results: Nine relevant studies were identified. The majority of the studies compared average CDT scores of cognitively healthy and mildly impaired subjects, and four of them identified significant mean differences. If reported, sensitivity and specificity have been mostly unsatisfactory.

Conclusion: CDT should not be used for MCI-screening.

Background: The aim of the study was to determine the correlation and agreement between the Mini-mental State Examination (MMSE) and Clock Drawing Test (CDT), administered and scored using Shulman's method (2000), in elderly Brazilian adults with very low levels of formal education.

Methods: CDT and MMSE tests, performed by a sample of 1118 elderly subjects from a population-based cohort, were evaluated. Spearman's correlation coefficient was calculated for the total sample and according to gender, age and schooling level. Agreement was assessed using receiver operating characteristic (ROC) analysis.

Results: CDTs with high scores had high corresponding MMSE scores whereas CDTs with low scores had a wide range of corresponding MMSE scores. Correlation was moderate (ρ = 0.64) and no difference was found according to gender, age or schooling level. For CDT cut-off 3/4, the best MMSE cut-off was 27/28 and agreement between tests was 75.1%.

Conclusions: Correlation between tests was moderate. Subjects who performed well on the CDT could be expected to obtain high MMSE scores. Although one test does not substitute for the other, the CDT may be more practical in developing countries where resources are limited and low education is common in the elderly, as well as in situations where time for assessment or screening is limited. Moreover, the CDT may be sensitive to cognitive domains not assessed by the MMSE.

Background: The 12-item Clock Reading Test (CRT) allows a fine-graded assessment of clock-reading ability. It has a strong focus on visuo-spatial processing and requires no executive processing. This study evaluated the reliability, validity, sensitivity and specificity of the CRT for the diagnosis of dementia and visuo-spatial dysfunction.

Methods: The CRT, the Clock Drawing Test (CDT) and other tests were applied to groups of 200 subjects with dementia, 105 subjects with mild cognitive impairment (MCI), 20 subjects with focal parietal lesions and 64 elderly control subjects.

Results: The CRT was found to be reliable and sensitive for the detection of cognitive impairment in parietal lesions, Alzheimer-, mixed- and Lewy Body dementia. Normal subjects and patients with MCI, frontotemporal dementia or cerebral small vessel disease showed little or no impairment.

Conclusion: CRT and CDT are clock-processing tests with different demand profiles. They can supplement each other in the neuropsychological diagnosis of dementia and visuo-spatial dysfunction.

Background: The aim of this study is to compare the results of magnetic resonance (MR) imaging, particularly the decline in hippocampal volume, of patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) with healthy age-matched controls, to examine the reliability of hippocampal volumetry in the early diagnosis of AD and the correlation of the severity of hippocampal atrophy with the severity of cognitive decline.

Methods: Twenty-six AD, 22 MCI and 15 normal cognitive status (NCS) patients were scanned with a 3 Tesla MR scanner. Hippocampus volumes were detected manually by Osiris 4.18.

Results: Multivariate regression analysis, which was performed to adjust the covariate effects of education, age, gender, hypertension and diabetes mellitus, showed that hippocampal atrophy was correlated with AD and MCI for right hippocampus; AD, MCI and age for left hippocampus independent of other parameters. A second regression analysis revealed that MMSE was correlated with hippocampal volume.

Conclusions: Hippocampal volumetry can be used in early diagnosis of cognitive impairment, as well as grading cognitive decline.