Development of scoring criteria for the clock drawing task in Alzheimer's disease.
OBJECTIVE
To investigate the reliability and validity of free-hand clock drawings, a frequently used measure of constructional apraxia, in patients with Alzheimer's disease.


METHODS
Survey for the purpose of testing reliability and validity of a new scale.


METHODS
Memory Disorder Clinic at a university-affiliated hospital in the Upper Midwest.


METHODS
Forty-six patients were diagnosed with clinically probable dementia of the Alzheimer type after a dementia evaluation, and 26 normal elderly controls were research volunteers without a history of cognitive dysfunction.


METHODS
Neuropsychological tests, dementia-related scales, and clock drawings rated by a new 20-item Clock Drawing Interpretation Scale. Reliability measures, correlations, and clustering of items in the CDIS.


RESULTS
The CDIS had inter-rater reliability (r = .94), internal consistence (rtt = .95), and reproducibility over a 6-month interval. CDIS scores were significantly correlated with two dementia-related scales and all neuropsychological tests and had the highest correlations with other measures of constructional apraxia. All but four Alzheimer patients (91%) and none of the controls had CDIS scores of 18 or less.


CONCLUSIONS
Clinicians may reliably screen patients with Alzheimer's disease with the clock-drawing task, a measure sensitive to deficits in constructional apraxia.
Mendez
M F
MF
Department of Neurology, St. Paul-Ramsey Medical Center/University of Minnesota, St. Paul 55101.
Ala
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Underwood
K L
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D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology; D001072:Apraxias / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology; D001154:Art; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening; D008609:Mental Status Schedule / Q000592:standards; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000592:standards*; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity