No abstract

Traditional tests used in the clinic to identify dementia, such as the mini-mental state examination (MMSE), are useful to identify severe cognitive impairments but might be less sensitive to detect more subtle age-related cognitive changes. Previously, the novel image–novel location (NINL) object recognition test was shown to be sensitive to detect effects of apolipoprotein E4, a risk factor for developing age-related cognitive decline and Alzheimer’s disease, in nondemented elderly. In the present longitudinal study, performance on the MMSE and the NINL tests were compared over a 4-year period. Individual NINL scores over this period were highly correlated. In addition, while MMSE scores did not change over the 4-year period, NINL scores did. In a final testing session of a subset of the participants, NINL scores correlated with logical memory and word recall lists, cognitive tasks used to detect dementia in the clinic, as well as clinical dementia rating scales. These results support that the NINL might be a valuable tool to assess age-related cognitive decline.

Previously we reported that Apolipoprotein E (ApoE) ε4 negatively affects performance in the novel-image-novel-location (NINL) object recognition test in healthy non-demented elderly human study participants. In this study, the participants were invited to return for testing sessions 6 and 18 months after the baseline session. Using a longitudinal study design, effects of ε4 on NINL test performance were assessed in study “dropouts”, participants that did not return for the second and/or third session(s), and “finishers”, participants that returned for all sessions. There were effects of ε4 on dropout rates and NINL total scores as well as sub-scores in both dropouts and finishers. NINL total score was a predictor of ε4 participant dropout. Compared to non-ε4 dropouts, ε4 dropouts had lower NINL scores. In contrast, ε4 finishers had higher NINL scores than non-ε4 finishers. Thus, the NINL test could be a valuable tool in detecting pre-clinical signs of age-related cognitive impairments, particularly those associated with ε4 risk.