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The Clock-Drawing Test (CDT) has been used to screen for Alzheimer's disease (AD) as a supplement to cognitive tests that focus on memory impairment. We examined a comprehensive scoring system of the CDT in screening of AD in a Chinese population and derived a simplified scoring system. All 403 (144 AD and 259 nondemented) subjects were administered the CDT, including both the drawing part (CDT-D) and the copying part (CDT-C). The Cognitive Abilities Screening Instrument and the Clinical Dementia Rating were also administered. Stepwise discriminant analysis was used to develop a simplified CDT scoring system. The optimal CDT cutoff scores (CDT-D: 10/11; CDT-C: 12/13) show intermediate sensitivity (CDT-D: 66.7%; CDT-C: 51.4%) and specificity (CDT-D: 74.5%; CDT-C: 74.1%). The simplified 3-item CDT scoring system, with a cutoff score of 2/3, has a sensitivity of 72.9% and a specificity of 65.6%; it can be used as a quick test for AD screening., (Copyright 2003 S. Karger AG, Basel)

We constructed a Chinese version of the cognitive component of the Alzheimer's Disease Assessment Scale (ADAS-Cog). In order to accommodate illiteracy, the Chinese version used pictures instead of words for assessing recall and recognition. The Chinese ADAS-Cog was administered to 125 individuals with no dementia, 127 with questionable dementia, and 77 with Alzheimer's disease (AD). Their age range was 51-92 years and their education range was 0-20 years. The Chinese ADAS-Cog had high internal consistency (Cronbach's alpha = 0.87) and very high interrater reliability (intraclass correlation coefficient, or ICC, = 0.99) and test-retest reliability (ICC = 0.96). It had high correlations with scores on the Clinical Dementia Rating Scale (Pearson's r = 0.85), the Cognitive Abilities Screening Instrument (CASI, Pearson's r = -0.88), and CASI-estimated scores on the Mini-Mental State Examination (Pearson's r = -0.85). Performance on the Chinese ADAS-Cog was uninfluenced by age or gender, nor by education level except within the low education range of 0-6 years. Its memory items were best for early detection of dementia; its language items were best for monitoring the progression of dementia. This study found that the Chinese ADAS-Cog is a good instrument for use with Chinese AD patients., (Copyright 2002 S. Karger AG, Basel)

Two experiments were designed to investigate effects of cueing upon aptitude for shifting by patients with Parkinson's disease. Subjects executed in alternation two different components of a task set over successive items in a list. We compared the costs of shifting when the stimulus ensemble remained constant from trial to trial ("uniform" lists), with the case in which a change of stimulus ensemble cued each shift of task ("mixed" lists). Shift costs with mixed lists were significantly smaller than those with uniform lists (Exp. 1, ns = 12). This suggests that patients with Parkinson's disease can benefit from cues about the stimulus ensemble in performing tasks. Patients' shifting performance was different from that of controls only in a reversal-shift condition of the previously consistent stimulus-response mappings (Exp. 2, ns = 12). This result suggests that patients with Parkinson's disease suffer from a specific but not a general deficit in ability to shift.