Brazilian Version of the Addenbrooke Cognitive Examination-revised in the Diagnosis of Mild Alzheimer Disease

Abstract

To investigate the accuracy of the Brazilian version of the Addenbrooke Cognitive Examination-revised (ACE-R) in the diagnosis of mild Alzheimer disease (AD). The ACE-R is an accurate and brief cognitive battery for the detection of mild dementia, especially for the discrimination between AD and frontotemporal dementia. The battery was administered to 31 patients with mild AD and 62 age-matched and education-matched cognitively healthy controls. Both groups were selected using the Dementia Rating Scale and were submitted to the ACE-R. Depression was ruled out in both groups by the Cornell Scale for Depression in Dementia. The performance of patients and controls in the ACE-R was compared and receiver operator characteristic curve analysis was undertaken to ascertain the accuracy of the instrument for the diagnosis of mild AD. The mean scores at the ACE-R were 63.10+/-10.22 points for patients with AD and 83.63+/-7.90 points for controls. The cut-off score <78 yielded high diagnostic accuracy (receiver operator characteristic area under the curve=0.947), with 100% sensitivity, 82.26% specificity, 73.8% positive predictive value, and 100% negative predictive value. The Brazilian version of the ACE-R displayed high diagnostic accuracy for the identification of mild AD in the studied sample.