Relevance of 10-min delayed recall in dementia screening

Within the context of early diagnosis of Alzheimer's disease (AD), there is a growing interest in neuropsychological screening tests. Amongst these tests, we focused on the largely used Memory Impairment Screen (MIS). The objective of the present work was to show that adding a 10-min delayed recall to the MIS, improves the test psychometric characteristics in order to detect dementia in the earliest stages. A prospective study was carried out on a cohort of 270 consecutive elderly ambulatory subjects attending the Broca Hospital Memory Clinic: normal controls (n = 67), mild cognitive impairment subjects (n = 98) and mildly demented patients [n = 105, Mini Mental State Examination (MMSE) = 23 +/- 4]. This study consisted in testing the advantage of the 10-min delayed recall entitled MIS-D compared with the MIS. At a cut-off score of 6, the MIS-D revealed satisfying psychometric characteristics with a sensitivity of 81% and a specificity of 91%, whilst the MIS alone indicated a sensitivity of 60% and a specificity of 88% in detecting dementia. In demented patients with MMSE score > or =26, MIS-D properties still remained satisfying (sensitivity: 75%, specificity: 92%). MIS-D is a more relevant screening test than MIS alone at very early stages of dementia.