Aims: This pilot study sought to determine whether the Malayalam adaptation of Addenbrooke's Cognitive Examination (M-ACE) can effectively identify patients with amnestic mild cognitive impairment (a-MCI) and the impact of measures of learning and free recall.
Materials and methods: A cohort of 23 patients with a-MCI aged between 55-80 years diagnosed as per current criteria and 23 group matched cognitively normal healthy controls (CNHC) were studied. The measures of acquisition and delayed recall were the Rey Auditory Verbal Learning Test (RAVLT) and Wechsler Memory Scale (WMS)-III (verbal and visual subsets) and Delayed Matching-to-sample Test (DMS)-48. Test scores of M-ACE registration and recall scores were included. To examine the differences in test performances between the groups, we compared the number of subjects with test scores less than 1.5 standard deviation (SD) of the control scores. Comparisons between a-MCI and controls were drawn using Fisher's exact test and Mann-Whitney U tests.
Results: M-ACE registration component ascertained on a 24-point scale failed to demonstrate any differences between a-MCI and controls (P = 0.665) as opposed to recall judged on a cumulative 10-point scale (P = 0.001). Significant differences were noted in RAVLT list learning (P < 0.001) and list recall (P = 0.003), WMS-III paragraph learning (P <0.001) and recall (P = 0.007), visual learning (P = 0.004) and recall (P = 0.001).
Conclusions: M-ACE recall scores are an effective screening tool to identify patients with suspected a-MCI. Both word list and paragraph learning and recall components have been found to be sensitive to concretely identify a-MCI and impairment on at least 2 tests should be considered in the diagnostic criteria of MCI rather than rely on a single screening battery.
Keywords: Learning; mild cognitive impairment; neuropsychology; recall.