Addenbrooke's Cognitive Examination III (ACE-III) is a screening test that was recently validated for diagnosing dementia. Since it assesses attention, language, memory, fluency, and visuospatial function separately, it may also be useful for general neuropsychological assessments. The aim of this study was to analyze the tool's ability to detect early stages of Alzheimer's disease and to examine the correlation between ACE-III scores and scores on standardized neuropsychological tests.

Our study included 200 participants categorized as follows: 25 healthy controls, 48 individuals with subjective memory complaints, 47 patients with amnestic mild cognitive impairment and 47 mild Alzheimer's disease, and 33 patients with other neurodegenerative diseases.

The ACE-III memory and language domains were highly correlated with the neuropsychological tests specific to those domains (Pearson correlation coefficient of 0.806 for total delayed recall on the Free and Cued Selective Reminding Test vs. 0.744 on the Boston Naming Test). ACE-III scores discriminated between controls and patients with amnestic mild cognitive impairment (AUC: 0.906), and between controls and patients with mild Alzheimer's disease (AUC: 0.978).

Our results suggest that ACE-III is a useful neuropsychological test for assessing the cognitive domains of attention, language, memory, and visuospatial function. It also enables detection of Alzheimer's disease in early stages.

The Addenbrooke's Cognitive Examination (ACE) and its Revised version (ACE-R) are relatively new screening tools for cognitive impairment that may improve upon the well-known Mini-Mental State Examination (MMSE) and other brief batteries. We systematically reviewed diagnostic accuracy studies of ACE and ACE-R.

Published studies comparing ACE, ACE-R and MMSE were comprehensively sought and critically appraised. A meta-analysis of suitable studies was conducted.

Of 61 possible publications identified, meta-analysis of qualifying studies encompassed 5 for ACE (1,090 participants) and 5 for ACE-R (1156 participants); of these, 9 made direct comparisons with the MMSE. Sensitivity and specificity of the ACE were 96.9% (95% CI = 92.7% to 99.4%) and 77.4% (95% CI = 58.3% to 91.8%); and for the ACE-R were 95.7% (95% CI = 92.2% to 98.2%) and 87.5% (95% CI = 63.8% to 99.4%). In a modest prevalence setting, such as primary care or general hospital settings where the prevalence of dementia may be approximately 25%, overall accuracy of the ACE (0.823) was inferior to ACE-R (0.895) and MMSE (0.882). In high prevalence settings such as memory clinics where the prevalence of dementia may be 50% or higher, overall accuracy again favored ACE-R (0.916) over ACE (0.872) and MMSE (0.895).

The ACE-R has somewhat superior diagnostic accuracy to the MMSE while the ACE appears to have inferior accuracy. The ACE-R is recommended in both modest and high prevalence settings. Accuracy of newer versions of the ACE remain to be determined.