Abstract: Objective To investigate the potential of the Clock Drawing Test (CTD) in differentiating the mild cognitive impairment (MCI) and Alzheimer's disease (AD). Methods Cognitive impaired patients admitted to the outpatient and inpatient of neurological department of our hospital from October 2011 to October 2013 were reviewed. There were 65 cases with MCI and 63 cases with AD. The scores of CDT were compared between them, and the sensitivity and specificity were evaluated with Receiver Operating Characteristic Curve. Results The MCI group and AD group matched in age, gender and education. The scores of Chinese version of the Mini-Mental State Examination and CDT were significantly defferent between the two groups. The sensitivity of 3-point CDT was 54.0% and the specificity was 80.9% in differentiating MCI and AD. Conclusion CDT is helpful to differentiate MCI from AD only in a set of assessment.

Key words: Clock Drawing Test, mild cognitive impairment, Alzheimer's disease, sensitivity, specificity