Clock Drawing Test in Mild Cognitive Impairment: Quantitative Analysis of Four Scoring Methods and Qualitative Analysis
ABSTRACT The role of the clock drawing test (CDT) as a screening tool for dementia has been evaluated. However, studies focusing on mild cognitive impairment (MCI) are still lacking. The purpose of this study was to verify the validity of the CDT as a screening method for MCI.
524 subjects aged 60 years and older were recruited in the community. Of these, 241 were diagnosed as not cognitively impaired (NCI) and 224 were classified as MCI. The CDT was scored according to the Freedman, Rouleau, Todd, and CERAD CDT and an additional comprehensive scoring system incorporating elements of most CDT for qualitative analysis.
The sensitivity and specificity of the 4 CDT scoring systems for MCI ranged from 40.7 to 56.4% and from 71.8 to 85.3%, respectively. The likelihood ratio and the positive and negative predictive values of the 4 CDT ranged from 18 to 29, 18.2 to 24.5 and from 55.9 to 78.4%, respectively. In qualitative analysis, a significantly lower performance in the clock numbers category was observed in the MCI group.
This study suggests that although some qualitative analyses could help in identifying MCI individuals, the CDT is insufficient as a screening method to distinguish MCI individuals from NCI individuals in a clinical setting.
- SourceAvailable from: Steffi Riedel-Heller
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- "However, the findings concerning the CDT's ability to differentiate between subjects with and without MCI are rather inconsistent (Lee et al., 2008; Pinto and Peters, 2009; Ehreke et al., 2010). For example, Yamamoto et al. (2004) found that the CDT has utility to screen for MCI, whereas Lee et al. (2008) did not recommend the use of the CDT as a screening instrument for MCI. The inconsistent results might particularly be due to the variety of versions of application and scoring. "
ABSTRACT: There is a strong demand for screening instruments for mild cognitive impairment (MCI), as a pre-stage of dementia. The clock drawing test (CDT) is widely used to screen for dementia, but the utility in screening for MCI remains uncertain. In particular, it is still questionable which scoring system is the best in order to screen for MCI. We therefore aimed to compare the utility of different CDT scoring systems for screening for MCI. In a sample of 428 subjects of the Leipzig Longitudinal Study of the Aged (LEILA 75+) study, CDT scores of different scoring systems were compared between subjects with and without MCI. Comparison of receiver operating characteristic (ROC; area under the curve, sensitivity, specificity) was performed and inter-rater reliability was calculated. The CDT scores differed significantly between MCI and non-MCI subjects according to all scoring systems applied. However, ROC of the CDT scores was not adequate. None of the present CDT scoring systems has sufficient utility to screen reliably for MCI. The clinical value of the CDT could be improved by using semi-quantitative scoring, having a wider score range and focusing on specific details of the clock (e.g. the hands and numbers).International Psychogeriatrics 08/2011; 23(10):1592-601. DOI:10.1017/S104161021100144X · 1.93 Impact Factor
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- "Minimental state examination (MMSE) and the clock drawing test (CDT)  were administered and scored by an experienced neuropsychologist blinded to the diagnosis. A simple scoring system was used for the CDT . The final possible scores ranged from zero (the worst) to four (the best). "
ABSTRACT: To investigate the biomarkers of vascular cognitive impairment (VCI), we analyzed 30 VCI patients and 30 healthy controls using proteome technology. Peptides in sera were purified using magnetic beads, and analyzed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and ClinProTool software. Twenty-four peptides were significantly differently expressed between VCI patients and controls. There were seven peptides selected for our diagnostic model. The sensitivity of the model measured by internal and external validation was 95% and 80% respectively, while the specificity was 100% for both. A peptide peak at 4963 m/z was chosen for identification by nano-liquid chromatography-electrospray ionization-tandem mass spectrometry (nano-LC-ESI-MS/MS). The amino acid sequence was consistent with the fragment of the trace-amine associated receptor 6 (TAAR6) in the human international protein index database. In conclusion, the specific fragment of TAAR6 may be important for clinical biomarkers in the diagnosis of VCI. The high specificity and sensitivity of the model may provide an appropriate method for screening VCI patients.Neuroscience Letters 08/2009; 463(1):6-11. DOI:10.1016/j.neulet.2009.07.056 · 2.03 Impact Factor
Conference Paper: Medical robots and micro machines[Show abstract] [Hide abstract]
ABSTRACT: Over the past 10 years we have developed micro-motion robots and micro-surgical robots for use in surgery on single living cells and populations of cells (tissue). These devices were designed to have both wide displacement bandwidths and high displacement dynamic ranges. Parallel drive beam bending mechanisms were developed together with displacement transducers able to transduce the high displacement dynamic range×bandwidth products that arise. High performance force reflecting human interfaces have also been developed to enable human control of the robots. Future work involves the development of new technologies for producing powerful autonomous micro-robots capable of moving within the human bodyMicro Machine and Human Science, 1995. MHS '95., Proceedings of the Sixth International Symposium on; 11/1995