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The Clock Drawing Test (CDT) has a known potential for the detection of cognitive impairment in populations with dementia, especially Alzheimer disease (AD). Our aim was to compare the clinical utility of 3 CDT scoring systems (Rouleau, Cahn, and Babins) in several pathologies with cognitive compromise from a tertiary center memory clinic. We selected patients with a clinical diagnosis of mild stage AD, behavioral variant frontotemporal dementia (FTD), vascular dementia (VaD), dementia with Lewy bodies (DLB), and Parkinson disease with dementia (PDD). The results showed significant differences between the several diagnoses with the following pattern of results: AD, DLB < FTD, VaD, PDD. Qualitative analysis of clock drawing errors confirmed the stimulus-bound response as a hallmark of AD, while conceptual deficit was significantly more prevalent in patients with AD and DLB. Our results supported the CDT potential as a cognitive screening measure for mild dementia, particularly sensitive to AD and DLB, especially when we used the Cahn scoring system and its analysis of qualitative errors. [ABSTRACT FROM AUTHOR]

The clock-drawing test (CDT) is widely used in clinical practice to diagnose and distinguish patients with dementia. It remains unclear, however, whether the CDT can distinguish among the early-onset dementias. Accordingly, we examined the ability of both quantitative and qualitative CDT analyses to distinguish behavioral variant frontotemporal dementia (bvFTD) and early-onset Alzheimer disease (eAD), the 2 most common neurodegenerative dementias with onset <65 years of age. We hypothesized that executive aspects of the CDT would discriminate between these 2 disorders. The study compared 15 patients with bvFTD and 16 patients with eAD on the CDT using 2 different scales and correlated the findings with neuropsychological testing and magnetic resonance imaging. The total CDT scores did not discriminate bvFTD and eAD; however, specific analysis of executive hand placement items successfully distinguished the groups, with eAD exhibiting greater errors than bvFTD. The performance on those executive hand placement items correlated with measures of naming as well as visuospatial and executive function. On tensor-based morphometry of the magnetic resonance images, executive hand placement correlated with right frontal volume. These findings suggest that lower performance on executive hand placement items occurs with involvement of the right dorsolateral frontal-parietal network for executive control in eAD, a network disproportionately affected in AD of early onset. Rather than the total performance on the clock task, the analysis of specific errors, such as executive hand placement, may be useful for early differentiation of eAD, bvFTD, and other conditions. [ABSTRACT FROM AUTHOR]

To compare clock test deficits in elderly patients with early onset depression (EOD) and late onset depression (LOD), we assessed 32 elderly healthy controls (HCs), 26 patients with EOD, and 27 patients with LOD with the clock drawing test (CDT), clock setting test, clock reading test, and the Tübingen Clock Questionnaire testing semantic memory about clock times. There was no significant difference in depression severity between patients with EOD and LOD. Patients with LOD had significantly lower scores on the CDT than patients with EOD and HCs. Semantic memory impairment concerning minute hand functionality was highly correlated with CDT performance and was significantly different between the EOD and the LOD groups. It can be suggested that significant differences in cognitive impairment severity between patients with EOD and LOD can be detected with CDT. Semantic memory impairment concerning minute hand functionality might affect CDT test results in elderly patients with depression. [ABSTRACT FROM AUTHOR]

Identification of individuals who will eventually develop dementia is critical for early intervention, treatment, and care planning. The clock drawing test (CDT) is a widely used cognitive screening tool that has been well accepted among clinicians and patients for its ease of use and short administration time. This review explores the value of the CDT for predicting the later development of dementia in cognitively intact older adults and patients with mild cognitive impairment (MCI). Additionally, we reviewed studies that examined the ability of the CDT to monitor declines in cognitive functioning over time. A PubMed literature search for articles that included a longitudinal analysis of the CDT was conducted. The search included articles published up to June 2013 and manual cross-referencing of bibliographies. Relevant studies were categorized, summarized, and critiqued. The consensus from the studies reviewed suggests that the CDT is a useful measure of cognitive decline over time. Conceptual clock drawing errors (eg, misrepresentation of time) detected this decline most effectively. In addition, the CDT appears to differentiate at baseline between cognitively intact older adults who will develop dementia up to 2 years postbaseline. Finally, the CDT has been found to differentiate between patients with MCI who will progress to dementia up to 6 years postbaseline. The CDT appears useful for the longitudinal assessment of cognitive impairment and together with other validated measures may be helpful for predicting conversion to dementia. Cost-effective and practical ways of predicting risk of dementia will become increasingly critical as we develop disease-modifying treatments. [ABSTRACT FROM AUTHOR]

Despite the wide use of clock drawing tests (CDTs) for screening cognitive impairment, their use in patients having Parkinson disease (PD) with dementia has not been systematically investigated until date. In this cross-sectional study, neurological and neuropsychiatric statuses of 1449 outpatients having PD with and without dementia were comprehensively assessed. The CDT revealed cognitive impairment in 42.7% of the 1383 patients whose drawings were available. Overall, CDT sensitivity and specificity were 70.7% and 68.9%, respectively. The positive and negative predictive values were 48.0% and 85.3%, respectively. In patients with depression, CDT specificity dropped significantly to 55.8% (71.3% in nondepressed patients, P < .001). Classification performance was not impacted by motor symptoms. The estimated classification performances and predictive values correspond to those reported previously for non-PD populations. Our results indicate that CDT is a suitable screening instrument in patients with PD, but test results from patients with depression warrant careful consideration. [ABSTRACT FROM AUTHOR]

The clock drawing test (CDT) has been used as a screening tool for identifying cognitive decline in individuals with Alzheimer disease (AD) and other dementias but has not been extensively evaluated for categorizing individuals with mild cognitive impairment (MCI). This study used both an established quantitative scoring system and a revised scoring method based on qualitative error criteria developed by Rouleau et al to demonstrate the sensitivity of the CDT to MCI. Participants were 66 cognitively healthy older adult, 33 individuals with MCI, and 33 individuals with AD. Sensitivity analyses of the 2 clock drawing methods revealed that the Modified Rouleau scoring method was more sensitive to MCI than the original Rouleau scoring system. Conceptual, graphic, and spatial-planning difficulties were the most commonly committed errors on the CDT across all groups, and conceptual errors along with graphic difficulties were committed more often in the MCI group than the cognitively healthy control group. Participants in the AD group exhibited greater deficits in all error categories and significantly lower total CDT scores compared to both the MCI and older adult controls. Findings observed in this study suggest that qualitative observations of clock drawing errors can help increase sensitivity of the CDT to MCI and that use of a more detailed scoring system is necessary to differentiate individuals with MCI from cognitively healthy older adults. [ABSTRACT FROM AUTHOR]

Based on previous findings, we hypothesized that Clock Test deficits in patients with Alzheimer disease (AD) are associated primarily with the impairment of semantic memory regarding the appearance and functionality of a clock. To scrutinize this hypothesis,we developed aClock Questionnaire that examined the semantic knowledge of the concept of a ''Clock'' and correlated scores from the questionnairewith performance in ClockDrawing, Clock Setting, and Clock Reading by healthy control participants and patients with mild cognitive impairment, early AD, and progressed AD. The Rey-Osterrieth-Complex- Figure is known to measure both visuospatial abilities and executive functions, and was chosen as a control variable. We found that deteriorated semantic memory best predicted Clock Test performance. In progressed AD, degraded knowledge regarding the appearance of a clock can explain the reduced ability to draw a clock face, while in early AD, impaired access to semantic knowledge about the minute hand might explain observed difficulties in drawing, setting, and reading the minute hand. [ABSTRACT FROM AUTHOR]

Objective: We aimed to evaluate the overall diagnostic accuracy of clock drawing test methods which require a defined time setting. In addition, diagnostic relevance of time setting was analyzed qualitatively. Methods: Clock drawing test performance of 462 consecutive memory clinic patients were analysed by 5 different clock drawing test methods. The sensitivity, specificity, positive and negative predictive value as well as the overall misclassification rate was calculated against a clinical diagnosis of dementia. Further, qualitative analysis of error types was done when subjects failed in the time setting task. Results: All clock drawing test methods that require time setting revealed higher sensitivities and superior negative predictive values as well as overall misclassification rates compared to methods which do not. Failure in the time setting task did not exclusively occur in dementia patients. However, error types which reflect a severely reduced capacity in abstract and conceptual thinking occurred exclusively in dementia patients. Discussion: Clock drawing test methods that require time setting should be favoured above methods which do not. An additional analysis of time setting errors may yield valuable diagnostic information. [ABSTRACT FROM AUTHOR]

The authors compared the accuracy of Addenbrooke's Cognitive Examination Clock Drawing Test scoring method with 8 standard Clock Drawing Test scoring methods in a Spanish speaking population of low educational level. A clinical group composed of 70 patients affected by dementia and 25 patients with memory complaints without dementia was compared with 72 controls matched for gender, age, and educational level. The clinical group was studied with standard neuropsychological instruments and neuroimaging. Clock Drawing Tests extracted from Addenbrooke's Cognitive Examination were randomly distributed and scored by 2 independent raters. There were statistically significant differences between the different scoring methods. Addenbrooke's Cognitive Examination Clock Drawing Test scoring method obtained and optimal areas under the curve and interrater reliability, showing no statistical differences with previously standardized systems. In our population, Addenbrooke's Cognitive Examination and the methods of Cahn, Mendez, Rouleau, Shulman, and Sunderland were of optimal and equivalent usefulness regarding dementia detection. [ABSTRACT FROM AUTHOR]

The aims of this research were to determine whether performance on the Clock Drawing Test (CDT) could accurately distinguish between older patients with depression and elder patients with depression and previously undocumented executive dysfunction and to determine if there was a correlation between CDT and depression severity. The authors studied 52 patients consecutively admitted to a geriatric psychiatry inpatient unit of a university hospital who met DSM-IV criteria for major depression or depression not otherwise specified but had no concurrent diagnosis of dementia. All the subjects completed the Mini-Mental State Examination (MMSE), Mattis Dementia Rating Scale (DRS), and the CDT, as well as the Geriatric Depression Scale (GDS). The patients were divided into 2 subgroups based on the DRS score: <129 (cognitive impairment) versus ≥129. Results indicated that the depressed patients with a score of DRS <129 had significantly lower CDT scores than did patients with DRS ≥129 and normal comparison subjects (P < .01). The results support the hypothesis that CDT score is lower in elderly depressed patients with executive dysfunction versus nondepressed seniors as well as depressed patients without executive dysfunction. [ABSTRACT FROM AUTHOR]