About time: neurocognitive correlates of stimulus-bound and other time setting errors in the Clock Drawing Test

OBJECTIVE

Previous findings suggest that time setting errors (TSEs) in the Clock Drawing Test (CDT) may be related mainly to impairments in semantic and executive function. Recent attempts to dissociate the classic stimulus-bound error (setting the time to "10 to 11" instead of "10 past 11") from other TSEs, did not support hypotheses regarding this error being primarily executive in nature or different from other time setting errors in terms of neurocognitive correlates. This study aimed to further investigate the cognitive correlates of stimulus-bound errors and other TSEs, in order to trace possible underlying cognitive deficits.

METHODS

We examined cognitive test performance of participants with preliminary diagnoses associated with mild cognitive impairment. Among 490 participants, we identified clocks with stimulus-bound errors (n = 78), other TSEs (n = 41), other errors not related to time settings (n = 176), or errorless clocks (n = 195).

RESULTS

No differences were found on any dependent measure between the stimulus-bound and the other TSErs groups. Group comparisons suggested TSEs in general, to be associated with lower performance on various cognitive measures, especially on semantic and working memory measures. Regression analysis further highlighted semantic and verbal working memory difficulties as being the most prominent deficits associated with these errors.

CONCLUSION

TSEs in the CDT may indicate underlying deficits in semantic function and working memory. In addition, results support previous findings related to the diagnostic value of TSEs in detecting cognitive impairment.

Clock Drawing Test Performance of Young Adults Based on a One-Shot Case Study

OBJECTIVE

The clock drawing test (CDT) is being used regularly by medical professionals in a variety of settings to aid in assessing cognitive functioning in adults of all ages. As our technological environment has changed significantly, because of the inception of this measure, the use of and exposure to the analog clock have diminished. We investigated whether young adults, who have grown up in a mainly digital world, can draw and tell time on an analog clock.

METHOD

Participants aged 18-30 years (N = 80, Mage = 24.2, SD = 3.93), who self-identified as having normal cognition, completed the CDT, as well as setting hands on a pre-drawn clock and identifying analog clock times.

RESULTS

About 25% of participants received a CDT score below the expected range. There was a moderate, positive correlation between analog clock hand setting and time identification in the group who scored below the expected range on the CDT only (rs(16) = 0.472, p = .048). Most participants reported not wearing an analog watch.

CONCLUSIONS

Based on these findings, the CDT should be used with caution to screen cognitive functioning in young adults (i.e., aged 18-30 years). Consideration of an alternative approach to screening cognition and modifying cognitive assessments in which the CDT is embedded is recommended for this population. These findings warrant further investigation into CDT performance in the young adult population.

Time setting errors in the Clock Drawing Test are associated with both semantic and executive deficits

The common requirement to set the time to "10 past 11" on the Clock Drawing Test is intended to elicit a stimulus bound response (SBR), in which the responder is "pulled" to the salient stimulus "10," resulting in hands set at "10 before 11." SBRs are considered markers of executive dysfunction, although this assumption has not yet been validated. We compared SBR and other time-setting errors on inhibitory control tests, hypothesizing that they represent related constructs. The role of semantic dysfunction in the formation of those errors was also investigated. We examined baseline test performance of participants with Mild Cognitive Impairment or a history of depression, and control participants, enrolled in a dementia prevention study. Among 258 participants, we identified clocks with SBRs (n = 16), other time errors (n = 22), or no errors at all (n = 42). Performance between the groups with SBRs and other time-setting errors did not differ on any of the executive tests, and both error groups performed significantly worse than the No Error group on the semantic tests. Control for covariates further supported semantic and executive components in time-setting errors. Both semantic and inhibitory control deficits may underlie time representation errors in general.

Patterns and characteristics of cognitive functioning in older patients approaching end stage kidney disease, the COPE-study

BACKGROUND

The prevalence of impaired cognitive functioning in older patients with end stage kidney disease (ESKD) is high. We aim to describe patterns of memory, executive function or psychomotor speed and to identify nephrologic, geriatric and neuroradiologic characteristics associated with cognitive impairment in older patients approaching ESKD who have not yet started with renal replacement therapy (RRT).

METHODS

The COPE-study (Cognitive Decline in Older Patients with ESRD) is a prospective cohort study including 157 participants aged 65 years and older approaching ESKD (eGFR ≤20 ml/min/1.73 m²) prior to starting with RRT. In addition to routinely collected clinical parameters related to ESKD, such as vascular disease burden and parameters of metabolic disturbance, patients received a full geriatric assessment, including extensive neuropsychological testing. In a subgroup of patients (n = 93) a brain MRI was performed.

RESULTS

The median age was 75.3 years. Compared to the normative data of neuropsychological testing participants memory performance was in the 24th percentile, executive function in the 18th percentile and psychomotor speed in the 20th percentile. Independent associated characteristics of impairment in memory, executive and psychomotor speed were high age, low educational level and low functional status (all p-values < 0.003). A history of vascular disease (p = 0.007) and more white matter hyperintensities on brain MRI (p = 0.013) were associated with a lower psychomotor speed.

CONCLUSION

Older patients approaching ESKD have a high prevalence of impaired memory, executive function and psychomotor speed. The patterns of cognitive impairment and brain changes on MRI are suggestive of vascular cognitive impairment. These findings could be of potentially added value in the decision-making process concerning patients with ESKD.

A Meta-Analysis of Neuropsychological Predictors of Outcome Following Stroke and Other Non-Traumatic Acquired Brain Injuries in Adults

A number of cognitive abilities have been reported to predict outcome following a non-traumatic acquired brain injury (ABI) in adults. However, the results are inconsistent. Furthermore, the unique and combined capacity of these cognitive abilities to predict ABI outcome has not been evaluated. Consequently, we employed meta-analysis and multiple regression to evaluate the capacity of various neuropsychological domains to predict two separate outcome variables in adults: (1) activities of daily living; and (2) quality of life. Based on the activities of daily living meta-analysis (N = 2384), we estimated the following significant bivariate effects: memory (r = .31, 95% CI: .20/.41]), language (r = .33, 95% CI:.26/.40), attention (r = .38, 95% CI: .30/.46]), executive functions (r = .29, 95% CI: .19/.39]), and visuospatial abilities (r = .41, 95% CI: .34/ .48). Based on the quality of life meta-analysis (N = 1037), we estimated the following significant bivariate effects: memory (r = .12, 95% CI: .03/.20]), language (r = .19, 95% CI: .06/ .32), attention (r = .30, 95% CI: .16/.44]), executive functions (r = .24, 95% CI: .12/.37) and visuospatial/constructional abilities (r = .30, 95% CI: .14/.46). Meta-analytic structural equation modelling (metaSEM) identified two significant, unique predictors of activities of daily living, attention and visuospatial abilities, and the model accounted for 21% of the variance (multiple R² = .21, 95%CI: .16/.26). For the corresponding quality of life metaSEM, no statistically significant unique predictors were identified, however, a significant multiple correlation was observed, multiple R² = .11 (95%CI: 04/.18). We conclude that practitioners may be able to predict, with some degree of accuracy, functional outcome following a stroke and other non-traumatic ABI in adults. We also provide some critical commentary on the nature and quality of the measures used in this area of research to represent the cognitive dimensions of interest.

Association of cardiovascular structure and function with cerebrovascular changes and cognitive function in older patients with end-stage renal disease

The Dutch prospective multicenter cohort study COPE (Cognitive decline in Older Patients with End stage renal disease) aimed to investigate the association of cardiovascular structure and function with cerebrovascular changes and cognitive function in 85 older patients with chronic kidney disease stage 4 and 5, awaiting either dialysis or conservative care. MRI was performed measuring aortic stiffness (pulse wave velocity [PWV]) and cardiac systolic function (ejection fraction and cardiac index). Outcomes were MRI-derived cerebrovascular changes (microbleeds, lacunes and white matter hyperintensities) and cognitive function (memory, executive function and psychomotor speed). Mean age was 76 years and 66% were male. No statistically significant associations were observed between cardiovascular parameters and cerebrovascular changes. Cognitive function was worse in patients with high compared to low PWV in all three cognitive domains. Although there were clinically relevant associations of high PWV with poor cognition in all domains, after adjustment for age, sex and education only the Trail Making Test A remained statistically significant (p=0.030). In conclusion, this study suggests that a higher PWV might be associated with lower cognitive function, suggesting that arterial stiffness may be an underlying mechanism of development of cognitive impairment in older patients with ESRD. Larger studies should replicate and extend these findings.

Usefulness of clock-drawing test in Indian older adults with diabetes mellitus

BACKGROUND

Clock-drawing test (CDT) is a simple, quick, and bedside cognitive screening test which measures different cognitive domains but has some limitations. The aim of this study was to examine the usefulness of CDT for Indian older adult based on a part of an ICMR-funded research project, New Delhi, India.

MATERIALS AND METHODS

Sample comprised seventy participants (38 controls and 32 cases) aged 60 years and above included according to the inclusion/exclusion criteria in a consecutive series. Participants, who gave written informed consent, residing permanently in the area of Chowk, Lucknow, constituted the study sample. Semistructured sociodemographic details and medical history pro forma, socioeconomic status scale, General Health Questionnaire-12 (GHQ-12), CDT, and Hindi cognitive screening test (HCST) were administered. Biochemical investigations were carried out, and blood glucose level (fasting ≤100 mg/dl and postprandial ≤140 mg/dl) was considered for having diabetes mellitus (DM). The participants were categorized into two groups: (1) case: participants with DM only and (2) control: participants without discernible abnormality of physical illness and GHQ negative. Data were analyzed using percentages, t-test, the Chi-square test, sensitivity, and specificity.

RESULTS

About 71.05% participants in control and 81.25% in the case group have cognitive impairment on CDT. Significantly higher illiterates (P < 0.05) were found to be significantly more cognitively impaired on HCST. CDT has a high level of sensitivity (0.71) and low specificity (0.23) when compared with HCST.

CONCLUSION

CDT had screening bias to Indian older adults as a higher number of literates (almost double) and illiterates (four times) were found to be cognitively impaired compared to on HCST. Usefulness of CDT to screen Indian older adults for cognitive impairment is debatable.

Quantitative and Qualitative Analyses of the Clock Drawing Test in Fall and Non-Fall Patients with Alzheimer's Disease

Aim

The clock drawing test (CDT) is widely used as a visual spatial ability test and screening test for dementia patients. The appearance frequency of qualitative errors obtained through the qualitative analysis of CDT may be related to the participant's falls. The aim of this study was to clarify the difference in the number of people who presented with qualitative errors in the CDT between a fall and non-fall group of patients with Alzheimer's disease (AD).

Methods

The CDT was implemented for 47 patients with AD. A quantitative analysis was conducted, and a qualitative analysis was performed for errors. The patients were divided into two groups based on their history of falls over the past year. The results of the CDT quantitative analysis were tested using the Mann-Whitney U test, and Fisher's exact test was employed to determine the difference in the number of people who presented with error types between the two groups (fall group, non-fall group) in the CDT qualitative analysis.

Results

In the quantitative analysis, a significant difference was found for the total scores, with the total CDT score of the fall group (n = 22) significantly lower than that of the non-fall group (n = 25) (p = 0.006, effect size: φ = 0.40). In the qualitative analysis, a significantly higher number of patients in the fall group than in the non-fall group presented with a conceptual deficit (p =0.001, φ = 0.51). No differences were found in the number of patients in the two groups who presented with the other five error types.

Conclusions

These results showed that a lower score in the CDT quantitative analysis might suggest an increased risk of falls. It was also clarified that a larger number of patients in the fall group than in the non-fall group presented with a conceptual deficit of the qualitative error types in the CDT. Therefore, these results suggest that the appearance of a conceptual deficit may be an index for the selection of patients with AD prone to falling when implementing fall prevention measures.

Clock Drawing Test in acute stroke and its relationship with long-term functional and cognitive outcomes

Objective: The Clock Drawing Test (CDT) is commonly used as a screening tool for the assessment of dementia. The association between the CDT in acute stroke and long-term functional and cognitive outcomes in this population is unknown. The present prospective study is the first to examine if CDT scores in the acute stage after stroke are related to long-term outcomes and to compare the predictive ability of two scoring systems in a large sample of stroke patients. Method: A total of 340 patients admitted to an acute stroke unit were included in the present study. Separate stepwise multiple linear regression analyses were performed with eight independent variables (demographic/pre-stroke variables - age, sex, premorbid functioning; stroke-related variables - stroke severity, localization; cognitive variables - Orientation Test, CDT [2 scoring systems]), and four dependent variables administered one year post-stroke (Barthel Index, modified Rankin Scale, Reintegration to Normal Living index, Global Deterioration Scale). Results: Although both CDT scoring methods were related to all long-term outcome measures, the more comprehensive scoring system was the only baseline variable that significantly explained the variance in outcome measures in all four multiple regression models. Conclusion: Performance on the CDT in acute stroke is related to long-term outcomes including patients' degree of independence in performing activities of daily living, the degree to which they achieved reintegration into daily occupations, and the degree of cognitive decline observed one-year post-stroke. Future studies are needed to clarify the nature of the relationship between different CDT scoring systems and post-stroke outcomes.

Qualitative analysis and identification of pattern of errors in Clock Drawing Tests of community-dwelling older adults

The Clock Drawing Test (CDT) is a frequently employed screening tool with different scoring systems. Quantitative and semi-quantitative scoring systems, such as Sunderland’s et al. (1989), do not discriminate different error patterns. Thus, the same score can represent a number of different neuropsychological profiles. Therefore, the use of a scoring method that emphasizes qualitative aspects to determine specific error patterns is fundamental.

Validity and Clinical Utility of Different Clock Drawing Test Scoring Systems in Multiple Forms of Dementia

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.

The Cognitive decline in Older Patients with End stage renal disease (COPE) study - rationale and design

BACKGROUND

Older patients with end stage renal disease (ESRD) are at increased risk for cognitive decline, but detailed studies of the magnitude of cognitive decline on dialysis or comprehensive conservative management (CCM) are lacking and the underlying pathophysiological mechanisms have poorly been studied.

OBJECTIVES

To describe the rationale and design of the COPE study. Study objectives are as follows. Firstly, to examine the severity of cognitive impairment in older patients reaching ESRD before dialysis and the rate of decline after dialysis or CCM initiation. Secondly, to study the association of blood biomarkers for microvascular damage and MRI derived measurements of small vessel disease with the rate of cognitive decline. Thirdly, to examine to what extent cardiac function is related to brain structure and perfusion in patients reaching ESRD. Finally, to study the association of cognitive and functional capacity with quality of life in pre-dialysis patients, as well as after dialysis or CCM initiation.

STUDY DESIGN AND METHODS

The COPE study is a prospective, multicenter cohort study in the Netherlands, including prevalent and incident pre-dialysis patients ≥65 years old with eGFR ≤20 ml/min/1.73 m², awaiting either dialysis or CCM initiation. At baseline extensive data is collected including a comprehensive geriatric assessment and laboratory tests. Brain and cardiac MRI for analysis of structural and functional abnormalities are performed at baseline and repeated following therapy change. All other measurements are repeated annually during four years of follow up, including an extra evaluation six months after initiation of dialysis.

CONCLUSIONS

Knowledge of the magnitude of cognitive decline and its underlying pathophysiological mechanism, as well as its impact on functionality and quality of life can eventually help to postulate an algorithm for well balanced decision making in treatment strategies in older patients reaching ESRD.

CLINICAL TRIAL REGISTRATION

The COPE study is registered on www.ccmo.nl (number: NL46389.058.13).

Scoring systems for the Clock Drawing Test: A historical review

The Clock Drawing Test (CDT) is a simple neuropsychological screening instrument that is well accepted by patients and has solid psychometric properties. Several different CDT scoring methods have been developed, but no consensus has been reached regarding which scoring method is the most accurate. This article reviews the literature on these scoring systems and the changes they have undergone over the years. Historically, different types of scoring systems emerged. Initially, the focus was on screening for dementia, and the methods were both quantitative and semi-quantitative. Later, the need for an early diagnosis called for a scoring system that can detect subtle errors, especially those related to executive function. Therefore, qualitative analyses began to be used for both differential and early diagnoses of dementia. A widely used qualitative method was proposed by Rouleau et al. (1992). Tracing the historical path of these scoring methods is important for developing additional scoring systems and furthering dementia prevention research.

Mapping the clockworks: what does the Clock Drawing Test assess in normal and pathological aging?

The Clock Drawing Test (CDT) is a cognitive screening tool used in clinical and research settings. Despite its role on the assessment of global cognitive functioning, the specific cognitive components required for test performance are still unclear. We aim to assess the role of executive functioning, global cognitive status, visuospatial abilities, and semantic knowledge on Shulman's CDT performance. Fifty-three mild cognitive impairment, 60 Alzheimer's dementia, and 57 normal elderly controls performed the CDT, the Frontal Assessment Battery, the Mini-Mental State Examination, the Stick Design Test, and a naming test (TN-LIN). An ordinal regression assessed specific neuropsychological influences on CDT performance. All the cognitive variables were related to the CDT, accounting for 53% of variance. The strongest association was between the CDT and executive functions, followed by global cognitive status, visuospatial processing, and semantic knowledge. Our result confirms the multidimensional nature of the test and the major role of executive functions on performance.

Neural correlates of the components of the clock drawing test

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.

Interrater Reliability of the Clock Drawing Task in the Occupational Therapy Adult Perceptual Screening Test

The clock drawing item in the Occupational Therapy Adult Perceptual Screening Test (OT-APST) screens for unilateral neglect and impairments in constructional skills. The purpose of this study was to re-evaluate the interrater reliability of the clock drawing item in the OT-APST following the addition of example clock drawings to the manual. This study also compared the interrater reliability for occupational therapy clinicians with that for final year occupational therapy students and examined clocks with poor interrater reliability for the individual scoring criteria.

Sixteen occupational therapy students and 15 practising occupational therapists scored 50 clocks drawn by people with stroke, using the OT-APST clock drawing criteria. Interrater reliability was determined for each rater in comparison to the gold standard, using intraclass correlation (ICC) and kappa statistics. Student and clinician interrater reliability were compared using t-tests. The scoring of clocks with poor agreement was examined further in order to identify disparities.

The student and clinician groups demonstrated excellent reliability for ICC (0.83 and 0.84 respectively) and moderate reliability for kappa statistics (0.58 and 0.59). The differences between the groups were not significant (p > 0.05). Scoring disparities were seen in the formation of the circle or in the placement of the numbers. The results support reliable scoring for the clock drawing item in the OT-APST.

Discrimination of dementia with lewy bodies from Alzheimer disease and Parkinson disease using the clock drawing test

OBJECTIVE

The authors' objective was to examine the ability of the Clock Drawing Test to discriminate Dementia with Lewy bodies from Alzheimer disease and Parkinson disease.

BACKGROUND

Recent advances in medical treatments for dementia underscore the importance of differentiating among dementia subtypes. Clinically, Dementia with Lewy bodies can often be difficult to discriminate from Alzheimer disease and Parkinson disease because of similar and overlapping cognitive and motor features. While the Clock Drawing Test has been shown to discriminate dementia from normal aging fairly accurately, less is known about its ability to discriminate between various dementia groups.

METHODS

Patients with Alzheimer disease (n = 22), patients with cognitively impaired Parkinson disease (n = 17), and patients with Dementia with Lewy bodies (n = 20), matched for age, education, and dementia severity, were compared on the Clock Drawing Test, scored for overall accuracy as well as the presence of specific error types.

RESULTS

There were no significant group differences on a global quantitative measure of Clock Drawing Test performance. With regard to differences on the error types evaluated, the patients with Dementia with Lewy bodies were more likely to make conceptual errors than the patients with Alzheimer disease and Parkinson disease, and the patients with Parkinson disease and Dementia with Lewy bodies made more planning errors than the patients with Alzheimer disease. Classification accuracy was fair, with 69% overall classification for Alzheimer disease versus Dementia with Lewy bodies, and 68% overall classification for Parkinson disease versus Dementia with Lewy bodies.

CONCLUSIONS

Although some differences may exist in the qualitative features of clock drawing performance between these patient groups, overall clock drawing performance is relatively similar, and as a single instrument, the Clock Drawing Test provides limited discrimination of Dementia with Lewy bodies from Alzheimer disease and Parkinson disease.