Clock Drawing Errors Research Articles

Detection of Alzheimer's Disease Using Logistic Regression and Clock Drawing Errors.

Alzheimer's disease is an incurable disorder that accounts for up to 70% of all dementia cases. While the prevalence of Alzheimer's disease and other types of dementia has increased by more than 160% in the last 30 years, the rates of undetected cases remain critically high. The present work aims to address the underdetection of Alzheimer's disease by proposing four logistic regression models that can be used as a foundation for community-based screening tools that do not require the participation of medical professionals. Our models make use of individual clock drawing errors as well as complementary patient data that is highly available and easily collectible. All models were controlled for age, education, and gender. The discriminative ability of the models was evaluated by area under the receiver operating characteristic curve (AUC), the Hosmer-Lemeshow test, and calibration plots were used to assess calibration. Finally, decision curve analysis was used to quantify clinical utility. We found that among 10 possible CDT errors, only 3 were informative for the detection of Alzheimer's disease. Our base regression model, containing only control variables and clock drawing errors, produced an AUC of 0.825. The other three models were built as extensions of the base model with the step-wise addition of three groups of complementary data, namely cognitive features (semantic fluency score), genetic predisposition (family history of dementia), and cardio-vascular features (BMI, blood pressure). The addition of verbal fluency scores significantly improved the AUC compared to the base model (0.91 AUC). However, further additions did not make a notable difference in discriminatory power. All models showed good calibration. In terms of clinical utility, the derived models scored similarly and greatly outperformed the base model. Our results suggest that the combination of clock symmetry and clock time errors plus verbal fluency scores may be a suitable candidate for developing accessible screening tools for Alzheimer's disease. However, future work should validate our findings in larger and more diverse datasets.

Ability of clock drawing errors on Mini-Cog test to predict development of delirium after major urological cancer surgery

Abstract Background This study aimed to evaluate the impact of the clock drawing test (CDT) on postoperative delirium and compare the abilities of the mini-cognitive (Mini-Cog) test and the CDT for predicting postoperative delirium after major urological cancer surgery. Materials and methods In this single-center retrospective observational study, we collected the medical records of patients who underwent major urologic cancer surgery and preoperative cognitive screening based on the Mini-Cog test consisting of the CDT and the 3-word recall task at our department in 2020–2021 (n = 387). Univariate and multivariate logistic regression analyses were used to identify the clinical risk factors for postoperative delirium. We also compared the ability of the CDT alone and the Mini-Cog test consisting of the CDT and 3-word recall task to predict postoperative delirium. Results A total of 117 patients (30%) had abnormal CDT results. Postoperative delirium occurred in 29 patients (7%). On multivariate analysis, American Society of Anesthesiologists physical status ≥3 (odds ratio [OR], 5.0; p = 0.01), abnormal CDT (OR, 4.8; p < 0.001), preoperative benzodiazepine use (OR, 4.9; p < 0.001), and operative time ≥237 minutes (OR, 3.0; p = 0.01) were independent risk factors for postoperative delirium. The area under the curve for predicting postoperative delirium was 0.709 for CDT alone and 0.743 for the Mini-Cog test. No significant intergroup difference was observed (p = 0.43). Conclusions The CDT served as a formal but simple tool with adequate predictive power to identify the risk of postoperative delirium among patients undergoing major urological cancer surgery. Effective screening using the CDT might help provide optimal urological care for older patients.

Variational autoencoder provides proof of concept that compressing CDT to extremely low-dimensional space retains its ability of distinguishing dementia

The clock drawing test (CDT) is an inexpensive tool to screen for dementia. In this study, we examined if a variational autoencoder (VAE) with only two latent variables can capture and encode clock drawing anomalies from a large dataset of unannotated CDTs (n = 13,580) using self-supervised pre-training and use them to classify dementia CDTs (n = 18) from non-dementia CDTs (n = 20). The model was independently validated using a larger cohort consisting of 41 dementia and 50 non-dementia clocks. The classification model built with the parsimonious VAE latent space adequately classified dementia from non-dementia (0.78 area under receiver operating characteristics (AUROC) in the original test dataset and 0.77 AUROC in the secondary validation dataset). The VAE-identified atypical clock features were then reviewed by domain experts and compared with existing literature on clock drawing errors. This study shows that a very small number of latent variables are sufficient to encode important clock drawing anomalies that are predictive of dementia.

Clock drawing errors in the Mini-Cog test predict postoperative delirium following transurethral resection of bladder tumors while awake

BackgroundIn urology, where the proportion of elderly patients is high, a simple, practical, and reliable screening tool to predict the development of postoperative delirium would be useful. This study aimed to evaluate the efficacy of the mini-cognitive assessment instrument (Mini-Cog) test and the clock drawing test (CDT) for predicting postoperative delirium after transurethral resection of bladder tumors (TURBT). MethodsWe conducted a retrospective cohort study of patients who underwent TURBT under awake spinal anesthesia, and who had preoperative cognitive screening based on the Mini-Cog test consisting of the CDT and a 3-word recall task, in our department between 2020 and 2021. We aimed to identify clinical risk factors for post-TURBT delirium and compared the ability of the CDT alone and the Mini-Cog test to predict post-TURBT delirium. ResultsOf the 229 eligible patients, eighty patients (35%) had abnormal CDT outcomes. Postoperative delirium occurred in 26 patients (11%), of whom 21 (81%) had an abnormal CDT. Multivariate analysis demonstrated that a decline in instrumental activities of daily living (odds ratio (OR), 3.1, p = 0.03), previous diagnosis of dementia (OR = 8.7, p = 0.01), and abnormal CDT (OR = 7.8, p < 0.001) were independent risk factors for post-TURBT delirium. The area under the receiver operating characteristic curve in predicting post-TURBT delirium was 0.759 for the CDT alone and 0.705 for the Mini-Cog test, which was not significantly different (p = 0.30). ConclusionsThe CDT from the Mini-Cog test served as a formal, simple, and brief screening tool for assessing cognitive function as its predictive power adequately identified the risk of postoperative delirium in patients undergoing TURBT under spinal anesthesia while awake.

Clock-drawing test in vascular mild cognitive impairment: Validity of quantitative and qualitative analyses

ABSTRACT Introduction The clock-drawing test (CDT) has been used as a screening tool to identify cognitive deficit in patients with dementia. However, it has not been extensively evaluated for categorizing patients with vascular mild cognitive impairment (vMCI). This study aimed to examine the discrimination of vMCI using various CDT scoring methods. Method A total of 120 vMCI patients and 119 normal control (NC) subjects were tested using three CDT quantitative scoring systems: the one from the Montreal Cognitive Assessment (MoCA) (CDT3) and the systems of Rouleau (CDT10) and Babins (CDT18). We used a revised scoring method to evaluate the effectiveness in differentiating vMCI patients from NC subjects, which combined the CDT10 quantitative score and three qualitative errors with a significantly higher prevalence in vMCI group (called hereinafter CDTcomb, including CDTcomb13 and CDTcomb16 based on different weights of the three error types). The sensitivity and specificity of the CDT methods were determined by the receiver operating characteristic (ROC) curve. The results of the scoring systems were compared with those of the Mini-Mental State Examination (MMSE). Results The results of the ROC analyses with the CDT3, CDT10, and CDT18 systems produced a sensitivity of 71.1%, 81.8%, and 60.3%, and a specificity of 66.12%, 58.68%, and 73.55%, respectively, for the diagnosis of vMCI. Compared with the separate MMSE score, the combination of MMSE with the CDT3, CDT10 and CDT18 scores did not increase the sensitivity and specificity. When three qualitative errors were incorporated into the CDT10 quantitative score, CDTcomb13 and CDTcomb16 provided a sensitivity of 87.6% and 86.78%, and a specificity of 74.79% and 80.67%, respectively, in differentiating vMCI patients from the NC group. Conclusion Our findings suggest that the combination of CDT quantitative score with qualitative observations of the clock-drawing errors can provide a better discrimination between vMCI patients and cognitively normal subjects.

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.

Visuoconstructional Impairment in Subtypes of Mild Cognitive Impairment

Clock Drawing Test performance was examined alongside other neuropsychological tests in mild cognitive impairment (MCI). We tested the hypothesis that clock-drawing errors are related to executive impairment. The current research examined 86 patients with MCI for whom, in prior research, cluster analysis was used to sort patients into dysexecutive (dMCI, n = 22), amnestic (aMCI, n = 13), and multidomain (mMCI, n = 51) subtypes. First, principal components analysis (PCA) and linear regression examined relations between clock-drawing errors and neuropsychological test performance independent of MCI subtype. Second, between-group differences were assessed with analysis of variance (ANOVA) where MCI subgroups were compared to normal controls (NC). PCA yielded a 3-group solution. Contrary to expectations, clock-drawing errors loaded with lower performance on naming/lexical retrieval, rather than with executive tests. Regression analyses found increasing clock-drawing errors to command were associated with worse performance only on naming/lexical retrieval tests. ANOVAs revealed no differences in clock-drawing errors between dMCI versus mMCI or aMCI versus NCs. Both the dMCI and mMCI groups generated more clock-drawing errors than the aMCI and NC groups in the command condition. In MCI, language-related skills contribute to clock-drawing impairment.

The Times They Are a-Changin': Clock Drawing and Prediction of Dementia.

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.

VISUOCONSTRUCTIONAL IMPAIRMENT IN SUBTYPES OF MILD COGNITIVE IMPAIRMENT

Clock Drawing Test performance was examined alongside other neuropsychological tests in mild cognitive impairment (MCI). We tested the hypothesis that clock-drawing errors are related to executive impairment. The current research examined 86 patients with MCI for whom, in prior research, cluster analysis was used to sort patients into dysexecutive (dMCI, n = 22), amnestic (aMCI, n = 13), and multidomain (mMCI, n = 51) subtypes. First, principal components analysis (PCA) and linear regression examined relations between clock-drawing errors and neuropsychological test performance independent of MCI subtype. Second, between-group differences were assessed with analysis of variance (ANOVA) where MCI subgroups were compared to normal controls (NC). PCA yielded a 3-group solution. Contrary to expectations, clock-drawing errors loaded with lower performance on naming/lexical retrieval, rather than with executive tests. Regression analyses found increasing clock-drawing errors to command were associated with worse performance only on naming/lexical retrieval tests. ANOVAs revealed no differences in clock-drawing errors between dMCI versus mMCI or aMCI versus NCs. Both the dMCI and mMCI groups generated more clock-drawing errors than the aMCI and NC groups in the command condition. In MCI, language-related skills contribute to clock-drawing impairment.

Poster #T193 SEX-DIFFERENCES IN THE RELATIONSHIP BETWEEN CANNABIS USE AND RISK OF ADMISSION IN YOUNG SUBJECTS WITH AN EARLY PSYCHOSIS: A 1-YEAR FOLLOW-UP STUDY

The clock drawing test (CDT) is a widely used dementia screening instrument that assesses executive and visuospatial abilities; studies in patients with Alzheimer's disease (AD) suggest frontoposterior networks to be involved in clock drawing. Clock drawing errors are also often observed in dementia with Lewy bodies (DLB), but the functional neuroanatomical substrate of impaired clock drawing has not been firmly established in this disorder. The present study was designed to provide initial evidence for brain metabolic alterations associated with CDT performance in DLB. Twenty-one patients with DLB were enrolled. CDT ratings were correlated with the regional cerebral metabolic rate of glucose (rCMRglc) measured by 18F-fluoro-2-deoxy-glucose positron emission tomography (18F-FDG PET) in the statistical parametric mapping software package SPM5, controlling for overall cognitive impairment as measured by the Mini-Mental-State Examination (MMSE) score. There was a significant negative association between test scores and rCMRglc in a left-hemispheric posterofrontal network including the temporoparietal and dorsal pre-motor cortices and the precuneus. The present study provides evidence for a direct association between frontoparietal dysfunction and impaired CDT performance in DLB. These findings also suggest that the CDT is an appropriate screening instrument for this disorder and that metabolic dysfunction, and therefore disease severity, is mirrored by performance on the test.

Numbers Written Counterclockwise in the Clock Drawing Test

Back to table of contents Previous article Next article LettersFull AccessNumbers Written Counterclockwise in the Clock Drawing TestHui-Ju Kao, M.D., and Tung-Hua Chiang, M.D.Hui-Ju KaoSearch for more papers by this author, M.D., and Tung-Hua ChiangSearch for more papers by this author, M.D.Published Online:1 Jan 2014https://doi.org/10.1176/appi.neuropsych.13030052AboutSectionsView articleSupplemental MaterialPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail View articleTo the Editor: A recent review (Windows to the Brain: The Clock Drawing Task: Common Errors and Functional Neuroanatomy)1 described Rouleau’s qualitative system and the relationship between clock-drawing errors and brain networks. Frontoparietal and frontostriatal circuits are important for visuospatial and executive functions necessary for accurate clock-drawing. We highlight the error of counterclockwise numbers as spatial and/or planning deficits according to Rouleau’s system and argue that most of correctly sequenced numbers 1–12 written counterclockwise may suggest memory-system involvement.There are various number-order errors in the clock drawing test (CDT; Figure 1), and examples of representative clock-drawing appear in the supplement attached to this letter. Mendez suggested that >6 correctly sequenced of the same symbol type falls under the concept of “numerical factors,” which encode semantic and spatially-coded knowledge that a clock-face contains the numbers 1–12 arranged to represent hours.2FIGURE 1. Relationships Among Number-Order Errors in the Clock Drawing TestThe reversed clock phenomenon (RCP) is an extreme example, in which 1–12 are written counterclockwise. Stroke patients with RCP often have lesions involving the right parietal lobe and subcortical area. Few stroke patients have parietotemporal lobe lesions, but lesions that involve multiple cortices make it difficult to clarify the role of the temporal lobes. RCP stroke patients show evidence of unilateral spatial neglect. Attentional orientation and visuospatial dysfunction, especially spatial representation, have been implicated in RCP stroke cases. Nevertheless, patients with Alzheimer’s disease (AD) and RCP did not show unilateral spatial neglect in Brugnolo’s study.3 The involvement of temporal lobes in AD patients with RCP supports the view that they are important for the visual-semantic retrieval of clock representation in AD patients.The CDT can involve an instruction to draw a clock-face from memory (i.e. draw-to-command). Alternatively, a subject can be asked to copy a clock (i.e., copy-to-command), which places less demand on executive functions and semantic memory.1 RCP or counterclockwise writing by dementia patients was mostly in the clockwise order for the copy-to-command. Two subacute stroke patients and RCP with different lesions can produce similar clocks for the draw-to-command (i.e., allochiria), but different clocks for the draw-to-copy.4,5 We suggest that the combination of copy-to-command and draw-to-command provides more information about the availability of cognitive functions.The CDT is simple and useful for monitoring dynamic cognitive change. A further understanding of the CDT results will help us design clinical rehabilitation programs to address specific cognitive impairments.Dept. of Neurology, Taichung Wizcare Hospital, Taichung City 404, TaiwanDept. of Neurology, Cheng-Ching Hospital, Taichung City 400, TaiwanCorrespondence: Hui-Ju Kao, M.D.; e-mail: kaohj.[email protected]comReferences1 Eknoyan D, Hurley RA, Taber KH: The clock drawing task: common errors and functional neuroanatomy. J Neuropsychiatry Clin Neurosci 2012; 24:260–265Link, Google Scholar2 Mendez MF, Ala T, Underwood KL: Development of scoring criteria for the clock drawing task in Alzheimer’s disease. J Am Geriatr Soc 1992; 40:1095–1099Crossref, Medline, Google Scholar3 Brugnolo A, Morbelli S, Dessi B, et al.: The reversed clock drawing test phenomenon in Alzheimer’s disease: a perfusion SPECT study. Dement Geriatr Cogn Disord 2010; 29:1–10Crossref, Medline, Google Scholar4 Lepore M, Conson M, Grossi D, et al.: On the different mechanisms of spatial transpositions: a case of representational allochiria in clock drawing. Neuropsychologia 2003; 41:1290–1295Crossref, Medline, Google Scholar5 Lepore M, Conson M, Ferrigno A, et al.: Spatial transpositions across tasks and response modalities: exploring representational allochiria. Neurocase 2004; 10:386–392Crossref, Medline, Google Scholar FiguresReferencesCited byDetailsCited ByNone Volume 26Issue 1 Winter 2014Pages E48-E49 Metrics PDF download History Published online 1 January 2014 Published in print 1 January 2014

The EDSS and Performance on Tests of Visuoconstruction, Working Memory, and Processing Speed in Multiple Sclerosis (P04.113)

Objective: We examined the combined relationship(s) between EDSS scores and working memory, visuoconstruction, and processing speed test performance. Background Expanded Disability Status Scale (EDSS) assesses functional disability, weighted mostly for ambulation. We examined the combined relationship(s) between EDSS scores and working memory, visuoconstruction, and processing speed test performance. Design/Methods: 36 Relapsing/ remitting MS patients (M age= 44.54±12.07) were assessed with the EDSS (M= 3.43±1.90) and neuropsychological tests measuring working memory (WMS-IV Symbol Span, serial order recall), visuoconstruction (total clock drawing errors), and processing speed (WAIS-III Digit Symbol raw score). Results: Simple correlations found that as the EDSS scores increased, performance on the WMS-IV Symbol Span worsen (r= -0.399, p Conclusions: Neuropsychological testing of working memory, visuoconstruction, and processing speed correlate well with the EDSS. This shows that progression of cognitive impairment closely follows the progression of physical impairment. Disclosure: Dr. Tabby has received personal compensation for activities with Biogen Idec as a speaker. Dr. Tabby has received research support from Sanofi-Aventis Pharmaceuticals, Inc. and Bayer Pharmaceuticals Corporation. Dr. Eppig has nothing to disclose. Dr. Nieves has nothing to disclose. Dr. Xu has nothing to disclose. Dr. DeLuca has received personal compensation for activities with Kessler Foundation Research Center and Biogen Idec.Dr. DeLuca has received research support from Biogen Idec. Dr. Libon has nothing to disclose.

Quantitative and Qualitative Analyses of the Clock Drawing Test in Mild Cognitive Impairment and Alzheimer Disease: Evaluation of a Modified Scoring System

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.

Metabolic alterations associated with impaired clock drawing in Lewy body dementia

The clock drawing test (CDT) is a widely used dementia screening instrument that assesses executive and visuospatial abilities; studies in patients with Alzheimer's disease (AD) suggest frontoposterior networks to be involved in clock drawing. Clock drawing errors are also often observed in dementia with Lewy bodies (DLB), but the functional neuroanatomical substrate of impaired clock drawing has not been firmly established in this disorder. The present study was designed to provide initial evidence for brain metabolic alterations associated with CDT performance in DLB. Twenty-one patients with DLB were enrolled. CDT ratings were correlated with the regional cerebral metabolic rate of glucose (rCMRglc) measured by 18F-fluoro-2-deoxy-glucose positron emission tomography ( 18F-FDG PET) in the statistical parametric mapping software package SPM5, controlling for overall cognitive impairment as measured by the Mini-Mental-State Examination (MMSE) score. There was a significant negative association between test scores and rCMRglc in a left-hemispheric posterofrontal network including the temporoparietal and dorsal pre-motor cortices and the precuneus. The present study provides evidence for a direct association between frontoparietal dysfunction and impaired CDT performance in DLB. These findings also suggest that the CDT is an appropriate screening instrument for this disorder and that metabolic dysfunction, and therefore disease severity, is mirrored by performance on the test.

Time that tells: critical clock-drawing errors for dementia screening

Clock-drawing tests are popular components of dementia screens but no single scoring system has been universally accepted. We sought to identify an optimal subset of clock errors for dementia screening and compare them with three other systems representative of the existing wide variations in approach (Shulman, Mendez, Wolf-Klein), as well as with the CDT system used in the Mini-Cog, which combines clock drawing with delayed recall. The clock drawings of an ethnolinguistically and educationally diverse sample (N = 536) were analyzed for the association of 24 different errors with the presence and severity of dementia defined by independent research criteria. The final sample included 364 subjects with > or = 5 years of education, as preliminary examination suggested different error patterns in subjects with 0-4 years of education and inadequate numbers of normal controls for reliable analysis. Eleven of 24 errors were significantly associated with dementia in subjects with > or = 5 years of education, and six were combined to identify dementia with 88% specificity and 71% sensitivity: inaccurate time setting, no hands, missing numbers, number substitutions or repetitions, or refusal to attempt clock drawing. Time setting was the most prevalent error at all dementia stages, refusal occurred only in moderate and severe dementia; and ethnicity and language of administration had no effect. All critical errors increased in frequency with dementia stage. This simplified scoring system had much better specificity than two other systems (88% vs 39% for Mendez's system - 63% for Shulman's) and much better sensitivity than Wolf-Klein's (71% vs 51%). Stepwise logistic regression found the simplified system to be more strongly predictive of dementia than the three other CDT systems of dementia. Substituting the new CDT algorithm for that used in the original CDT Mini-Cog improved the Mini-Cog's specificity from 89 to 93% with minimal change in sensitivity. Only six errors need be assessed to capture most of the power of clock drawing to discriminate between people with dementia and normal subjects, and improves specificity over older systems in subjects with > or = 5 years of education. These errors require minimal conceptual classification and are easily detected and scored by non-specialists.

Clock drawing errors in dementia: neuropsychological and neuroanatomical considerations.

A clock drawing test scoring system is presented to explore the neuropsychological/neuroanatomic components underlying clock drawing in patients initially diagnosed with Alzheimer disease, ischemic vascular dementia associated with white matter alterations, and Parkinson disease. Fourteen clock drawing test errors were scored to create 4 clock drawing test subscales that assess different underlying cognitive operations. In the command condition, errors on the Time subscale were correlated with impairment on executive control measures. In the copy condition, errors on the Perseveration/Pull to Stimulus subscale was also correlated with executive control measures. Patients presenting with mild (low) magnetic resonance imaging white matter alterations, significant (high) white matter alterations, and Parkinson disease were compared. In the command condition, the low white matter alterations group made fewer total errors than the Parkinson disease group. In the copy condition, the low white matter alterations group made fewer errors on the Time, Spatial Layout, and Perseveration/Pull to Stimulus clock drawing test subscales than the high white matter alterations or Parkinson disease groups. Few differences were noted between the high white matter alterations and Parkinson disease groups. Our data suggest that heavy demands on executive control associated with the interruption of large-scale cortical-subcortical neural networks underlie impairment in clock drawing in mild dementia.

The Clock Test: A Sensitive Measure To Differentiate Normal Elderly from Those with Alzheimer Disease

To examine the clinical utility of the Clock Test for identifying dementia. Group comparisons. A hospital-based out-patient diagnostic clinic. Volunteer sample of elderly individuals (normal elderly, NE, n = 62) and a referred sample of probable Alzheimer Disease (AD, n = 58) patients meeting NINCDS-ADRDA criteria. The Clock Test is composed of three components: Clock Drawing, Clock Setting, and Clock Reading. A detailed scoring system for qualitative as well as quantitative evaluation of Clock Drawing errors was used. Five time settings, varying in level of complexity, were used to evaluate Clock Setting and Clock Reading. The groups differed significantly on Clock Drawing, Clock Setting, and Clock Reading (P less than 0.001). On Clock Drawing, the AD group made significantly more errors of omission and misplacement of numbers than the NE group (P less than 0.001). Using cut-off scores derived to maximize separation between the groups to define deficits in performance, the sensitivity and specificity for the diagnosis of AD of Clock Drawing, Clock Setting, and Clock Reading were 92% and 86%, 87% and 97%, 92% and 85%, respectively. Using a criterion of deficits on two or more of the three components, sensitivity and specificity increased to 94% and 93%, respectively. Deficits on clock drawing in AD may be reflective of a generalized disturbance in the conceptualization of time rather than constructional apraxia, per se. The functionally relevant components of Clock Setting and Clock Reading combined with Clock Drawing make the Clock Test particularly useful as a screening and research tool for AD.

Clock drawing in the screening assessment of cognitive impairment in an ambulatory care setting: A preliminary report

In an exploratory study to assess the utility of clock drawing as a screening test for cognitive impairment in medical/surgical outpatients, clock drawing and the 6-item Orientation-Memory-Concentration Test (OMCT) were administered to over 400 randomly selected ambulatory patients over the age of 55 in a busy inner-city hospital. The clock drawing test was completed by 431 patients, and 471 completed the OMCT. Clock drawing errors suggestive of moderate-to-severe cognitive impairment were found in 42.7% of patients; OMCT errors suggestive of moderate-to-severe cognitive impairment were found in 35.4% of the population tested. The clock drawing test might represent a quick-screen for cognitive impairment in an older general medical/surgical outpatient population, and might help identify patients not otherwise recognized as potentially unable to fully understand treatment recommendations.