Comments on the executive control of clock-drawing

Diagnostic accuracy of the Clock Drawing Test in screening for early post-stroke neurocognitive disorder: the Nor-COAST study

BACKGROUND

Post-stroke neurocognitive disorder, though common, is often overlooked by clinicians. Moreover, although the Montreal Cognitive Assessment (MoCA) has proven to be a valid screening test for neurocognitive disorder, even more time saving tests would be preferred. In our study, we aimed to determine the diagnostic accuracy of the Clock Drawing Test (CDT) for post-stroke neurocognitive disorder and the association between the CDT and MoCA.

METHODS

This study is part of the Norwegian Cognitive Impairment After Stroke study, a multicentre prospective cohort study following patients admitted with acute stroke. At the three-month follow-up, patients were classified with normal cognition, mild neurocognitive disorder, or major neurocognitive disorder according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria. Any neurocognitive disorder compromised both mild- and major neurocognitive disorder. The CDT at the three-month assessment was given scores ranging from 0 to 5. Patients able to complete the CDT and whose cognitive status could be classified were included in analyses. The CDT diagnostic accuracy for post-stroke neurocognitive disorder was identified using receiver operating characteristic curves, sensitivity, specificity, positive predictive value, and negative predictive value. The association between the MoCA and CDT was analysed with Spearman's rho.

RESULTS

Of 554 participants, 238 (43.0%) were women. Mean (SD) age was 71.5 (11.8) years, while mean (SD) National Institutes of Health Stroke Scale score was 2.6 (3.7). The area under the receiver operating characteristic curve of the CDT for major neurocognitive disorder and any neurocognitive disorder was 0.73 (95% CI, 0.68-0.79) and 0.68 (95% CI, 0.63-0.72), respectively. A CDT cutoff of < 5 yielded 68% sensitivity and 60% specificity for any neurocognitive disorder and 78% sensitivity and 53% specificity for major neurocognitive disorder. Spearman's correlation coefficient between scores on the MoCA and CDT was 0.50 (95% CI, 0.44-0.57, p < .001).

CONCLUSIONS

The CDT is not accurate enough to diagnose post-stroke neurocognitive disorder but shows acceptable accuracy in identifying major neurocognitive disorder. Performance on the CDT was associated with performance on MoCA; however, the CDT is inferior to MoCA in identifying post-stroke neurocognitive disorder.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT02650531). Retrospectively registered January 8, 2016.

Validation of the self-reported domains of the Edmonton Frail Scale in patients 65 years of age and older

INTRODUCTION

In the era of virtual care, self-reported tools are beneficial for preoperative assessments and facilitating postoperative planning. We have previously reported the use of the Edmonton Frailty Scale (EFS) as a valid preoperative assessment tool.

OBJECTIVE

We wished to validate the self-reported domains of the EFS (srEFS) by examining its association with loss of independence (LOI) and mortality.

METHODS

This is a post-hoc analysis of a single-institution observational study of patients 65 years of age or older undergoing multi-specialty surgical procedures and assessed with the EFS in the preoperative setting. Exploratory data analysis was used to determine the threshold for identifying frailty using the srEFS. Procedures were classified using the Operative Stress Score (OSS) scored 1 to 5 (lowest to highest). Hierarchical Condition Category (HCC) was utilized to risk-adjust. LOI was described as requiring more support at discharge and mortality was defined as death occurring up to 30 days following surgery. Receiver operating characteristic (ROC) curves were used to determine the ability of the srEFS to predict the outcomes of interest in relation to the EFS.

RESULTS

Five hundred thirty-five patients were included. Exploratory analysis confirmed best positive predictive value for srEFS was greater or equal to 5. Overall, 113 (21 percent) patients were considered high risk for frailty (HRF) and 179 (33 percent) patients had an OSS greater or equal to 5. LOI occurred in 7 percent (38 patients) and the mortality rate was 4 percent (21 patients). ROC analysis showed that the srEFS performed similar to the standard EFS with no difference in discriminatory thresholds for predicting LOI and mortality. Examination of the domains of the EFS not included in the srEFS demonstrated a lack of association between cognitive decline and the outcomes of interest. However, functional status assessed with either the Get up and Go (EFS only) or self-reported ADLs was independently associated with increased risk for LOI.

CONCLUSION

This study shows that self-reported EFS may be an optional preoperative tool that can be used in the virtual setting to identify patients at HRF. Early identification of patients at risk for LOI and mortality provides an opportunity to implement targeted strategies to improve patient care.

Evaluation of Cognitive Functions in Traumatic Brain Injury Patients Using Mini Mental State Examination and Clock Drawing Test

Background:

Traumatic brain injuries (TBIs) are the leading cause of morbidity, mortality, disability, and socioeconomic losses globally, but of more concern, in India and other developing countries. The Mini mental state examination (MMSE) and clock drawing test (CDT) are the two mostly adapted methods for cognitive impairment screening. Therefore, it is necessary to establish a robust evaluation system exclusively for post-TBI cognitive impairment.

Materials and Methods:

One hundred and thirty-four cases treated previously at the health facility for TBIs were evaluated for cognitive functions during the follow-up period ranging from 3 weeks to 6 months in the out-patient department. All cases underwent mini-mental score examination (MMSE) and CDT to assess their cognitive performances. The data were analyzed statistically using Chi-square and ANOVA tests of significance.

Results:

Statistically significant association (P < 0.001) between the cognitive status of patients on the basis of overall MMSE score and the site of brain injury was observed. It was noted that 76 (56.7%) of the cases had cognitive impairment (MMSE score <24) with majority 44 (32.8%) patients having frontal lobe injuries, followed by 14 (10.1%) having brain injuries in the temporal lobe. On the other hand, using CDT score, it was observed that 102 (76.1%) of the cases had cognitive impairment (CDT score <5) with the majority 49 (36.6%) cases having frontal lobe injury followed by 19 (14.2%) having brain injury in the parietal lobe.

Conclusion:

The CDT was able to access cognitive function disruption in those patients, in whom the mini-mental score examination was not able to assess the same, and this difference in detection capabilities of both the tests was statistically found significant.

Disentangling the relationship between cognitive estimation abilities and executive functions: a study on patients with Parkinson's disease

The cognitive estimation test (CET) measures cognitive estimation abilities: it assesses the ability to apply reasoning strategies to answer questions that usually cannot lead to a clear and exact reply. Since it requires the activation of an intricate ensemble of cognitive functions, there is an ongoing debate in the literature regarding whether the CET represents a measurement of global cognitive abilities or a pure measure of executive functions. In the present study, CET together with a neuropsychological assessment focused on executive functions was administered in thirty patients with Parkinson's disease without signs of dementia. The CET correlated with measures of verbal working memory and semantic knowledge, but not with other dimensions of executive domains, such as verbal phonemic fluency, ability to manage real-world interferences, or visuospatial reasoning. According to our results, cognitive estimation abilities appeared to trigger a defined cognitive path that includes executive functions, namely, working memory and semantic knowledge.

Early Cognitive Impairment: Role of Clock Drawing Test

BACKGROUND

Folstein's Mini Mental Status Examination (MMSE) often fails to identify executive dysfunction even if quite severe. Detailed neuropsychological tests and extensive bedside tests are available to evaluate executive function, but most of them are time consuming. This study was done to determine the value of a Clock Drawing Test (CDT) as a simple tool to identify cognitive dysfunction in various neurological disorders and to assess its utility as an adjunct to MMSE in identifying executive dysfunction in a a busy out patient department (OPD).

METHODS

A total of 81 patients suffering from neurological disorders and 81 controls were studied. All subjects received the MMSE and the CDT. The CDT is divided into an unprompted task that is sensitive to executive control (CDT 1) and a copying task which is not (CDT 2).

RESULT

All the three tests (CDT 1, CDT 2 and MMSE) could recognize cognitive and executive function deficits, when compared with age and sex matched controls (p < 0. 001). CDT scores correlated strongly with the level of executive function deficits. CDT+MMSE detected 95% cases as abnormal as compared to 47% detected by MMSE alone.

CONCLUSION

CDT along with MMSE can detect executive control deficits and cognitive deficits. The CDT 1 tests executive control performance, while CDT 2 tests posterior cortical deficits.

Analysis of measures of functional and cognitive ability for aging adults with cardiac and vascular disease

Baseline and follow-up assessments of functional and cognitive status are essential for aging patients who survive acute cardiac and vascular disease, as they are faced with new medications and implementing changes in lifestyle. Because declining functional and/or cognitive status will interfere with treatment regimens and taking prescribed medications, it is imperative that healthcare providers develop an understanding of approaches to functional and cognitive assessment that can be used with aging patients, selecting those most appropriate for the venue in which they practice and for their particular patient population.

Improvement pattern in the clock drawing test in early Alzheimer's disease

OBJECTIVE

The aim of this paper was to compare the performance of a group of patients with early Alzheimer's disease (EAD) against a control group of healthy control (HC) subjects in the Clock Drawing Test (CDT), i.e. verbal command versus copying of a clock model presented to the subject.

PATIENTS AND METHODS

The authors have studied 140 subjects; 70 patients with probable EAD, with a mean age of 76.4 +/- 7.64 years and a clinical dementia rating stage 1 (mild dementia), and 70 HC with a mean age of 75.16 +/- 6.34 years.

RESULTS

Patients in the EAD group obtained significantly higher scores on the copy command mode than on the verbal command mode (Z = -7.129, p < 0.001)--improvement pattern of the CDT--whereas no statistically significant differences were found in the HC group (Z = -2.001, p < 0.080). Within the group of EAD patients, we have noticed that there is a correlation between the copy command mode and the visual-constructive functions of the Cambridge Cognitive Examination (CAMCOG) (r = 0.607, p < 0.01), while the memory functions of the CAMCOG correlate with the verbal command mode (r = 0.704, p < 0.01).

CONCLUSIONS

In our study, the EAD patients show an improvement pattern in the execution of the CDT copy command in comparison with the execution of the CDT verbal command, which we did not observe in the HC group. Such results might be associated with a greater deterioration of the memory functions when compared with the visual-constructive ones in the patients with EAD.

Clock drawing, clock reading, clock setting, and judgment of clock faces in elderly people with dementia and depression

OBJECTIVES

To assess patient performance on different clock tasks.

DESIGN

Group comparisons.

SETTING

A hospital-based memory clinic; inpatient and outpatient memory clinic.

PARTICIPANTS

Patients with dementia (n=30), patients with depression (n=30), and healthy controls (n=30).

MEASUREMENTS

General neuropsychological tests, clock drawing tests, and three additional clock tasks: clock reading, clock setting, and judgment of clock faces (each comprising 12 items).

RESULTS

Demented patients differed significantly from the control and depression groups on all clock tasks; controls and depressed patients differed only in the clock-setting task. A comparison between tasks showed that clock setting was the most difficult, which differentiated best between diagnostic groups. Groups differed not only in overall performance scores, but also in error characteristics.

CONCLUSION

Overall, study results indicate that clock setting is a sensitive task that may prove to be a valuable tool when screening for dementia.

On the different mechanisms of spatial transpositions: a case of representational allochiria in clock drawing

In the present paper, we describe a neglect patient who showed allochiria in copying and drawing a clock from memory. To verify the mechanisms of allochiria in our patient, we designed an experimental investigation including two conditions: to write single hours and to copy their spatial locations, one at a time onto blank circles. The patient showed spatial transpositions in writing hours on blank dials, but did not show allochiria in the reproduction of spatial locations. These findings suggest that the patient could not represent in her mind appropriate spatial coordinates of each hour with respect to the whole clock face. These data are in contrast with findings reported in other patients and demonstrate that constructional allochiria associated with spatial neglect may derive from different causal mechanisms. Our experimental investigation has thus paved the way for a distinction between an "attentional" and a "representational" allochiria.

Clock drawing: analysis in a retirement community

OBJECTIVE

To test the hypothesis that performance on a clock-drawing test in a mailed survey to an older cohort is associated with known and potential risk and protective factors for Alzheimer's disease.

DESIGN

The Leisure World Cohort Study is an ongoing study, begun in 1981, of nearly 14,000 older adults. In November 1992, the 8,406 living cohort members were mailed a follow-up questionnaire.

SETTING

Leisure World Laguna Hills, a southern California retirement community.

PARTICIPANTS

The study population is a predominantly white, well-educated, upper-middle-class community; approximately two-thirds are women. Data from 4,843 cohort members (mean age 80 years; range 52-101) were analyzed.

MEASUREMENTS

The questionnaire included a clock-drawing task: a predrawn circle 3 1/4 inches (8.3 cm) in diameter was provided with instructions "In the circle below, draw in the numbers as on a clock face. Make no erasures." Clocks were scored on 7 items: all numbers 1-12 present without adding extra or omitting numbers, sequencing of numbers, position of numbers, orientation of numbers to circle, consistent number style (either Arabic or Roman), tilt of numbers, and superfluous marks. A total clock score was calculated by summing the number of correct individual items (0-7). We also classified individuals as cognitively impaired by a previously suggested method: individuals were affected if they did not have three numbers drawn in the upper left quadrant of the clock face.

RESULTS

Ninety percent or more of the participants across all ages placed the numbers 1 to 12 on their clocks without omissions or additions; 35% completed the clock drawing without error. The mean total clock scores decreased with each successive 5-year age group in both men and women. Regression analysis indicated a significant effect for age (b = -0.15, P <.0001), education (b = 0.05, P =.0001), smoking (b = 0.13, P =.03), and female gender (b = -0.05, P =.05) and a marginally significant effect of nonrheumatoid arthritis (b = 0.05, P =.07) on total clock score. No other measured variable had a significant effect. Cognitively impaired individuals were more likely to be female and older. After adjusting for age and gender, they were also more likely to be hypertensive and to have taken blood pressure medication and less likely to be college graduates, have glaucoma or arthritis, and to have taken vitamin supplements.

CONCLUSION

The clock-drawing task is an appealing measure of cognitive function for large epidemiological studies because it is a simple, self-administered test that is easily adapted to mail surveys and correlates with more-detailed and more-time-consuming cognitive screens. Although it is relatively free of influence by language, cultural, or ethnic factors, our study shows that even in a highly educated population, clock drawing is influenced by educational level and other known risk factors for Alzheimer's disease. Thus a clock-drawing task may help predict cognitive frailty and future disability in older people. Such determination can direct high-risk individuals to earlier diagnosis, potential therapies, and better management.

CLOX: an executive clock drawing task

OBJECTIVE

To describe a clock drawing task (CLOX) designed to elicit executive impairment and discriminate it from non-executive constructional failure.

SUBJECTS

90 elderly subjects were studied (45 elderly and well persons from the independent living apartments of a continuing care retirement community and 45 patients with probable Alzheimer's disease). The clock drawing performance of elderly patients was compared with that of 62 young adult controls.

METHODS

Subjects received the CLOX, an executive test (EXIT25), and the mini mental state examination (MMSE). The CLOX is divided into an unprompted task that is sensitive to executive control (CLOX1) and a copied version that is not (CLOX2). Between rater reliability (27 subjects) was high for both subtests.

RESULTS

In elderly subjects, CLOX subscores correlated strongly with cognitive severity (CLOX1: r=-0.83 v the EXIT25; CLOX2: r=0.85 v the MMSE). EXIT25 and MMSE scores predicted CLOX1 scores independently of age or education (F(4,82)=50.7, p<0.001; R2=0.71). The EXIT25 accounted for 68% of CLOX1 variance. Only the MMSE significantly contributed to CLOX2 scores (F(4,72)= 57.2, p<0.001; R2=0.74). CLOX subscales discriminated between patients with Alzheimer's disease and elderly controls (83.1% of cases correctly classified; Wilkes' lambda=0.48, p<0.001), and between Alzheimer's disease subgroups with and without constructional impairment (91.9% of cases correctly classified; Wilkes' lambda=0.31, p<0.001).

CONCLUSIONS

The CLOX is an internally consistent measure that is easy to administer and displays good inter-rater reliability. It is strongly associated with cognitive test scores. The pattern of CLOX failures may discriminate clinical dementia subgroups.