The Diagnostic Value of a Short Memory Test: The TNI-93

Background: The TNI-93 is a quick memory test designed for all patients regardless of their education level. A significant proportion of patients with Alzheimer's disease (AD) are illiterate or poorly educated, and only a few memory tests are adapted for these patients. Objective: In this study we aimed at assessing the diagnostic value of the TNI-93 for diagnosis of patients with biologically confirmed amyloid status. Methods: We included all patients who had an analysis of AD cerebrospinal fluid biomarkers, a neuropsychological assessment including a TNI-93 and an anatomical brain imaging at Avicenne Hospital between January 2009 and November 2019. We compared the TNI-93 scores in patients with amyloid abnormalities (A+) and patients without amyloid abnormalities (A-) according to the AT(N) diagnostic criteria. Results: 108 patients were included (mean age: 66.9 +/- 8.5 years old, mean education level: 8.9 +/- 5.2 years). Patients from the A + group (N= 80) were significantly more impaired than patients from the A- group (N= 28) on immediate recall (A+: 5.9 +/- 2.8; A-: 7.4 +/- 2.6; p =0 .001), free recall (A+: 3.5 +/- 2.7; A-: 5.9 +/- 2.8; p < 0.001), total recall (A+: 5.7 +/- 3.5; A-: 7.8 +/- 2.8; p < 0.001), and on number of intrusions during the recall phase (A+: 1 +/- 1.8; A-: 0.1 +/- 0.3;p = 0.002). ROC curves revealed that the best scores to discriminate A + from A- patients were immediate recall (Area under curve (AUC): 0.70), number of encoding trials (AUC: 0.73), free recall (AUC: 0.74), and total recall (AUC: 0.74). Conclusion: The TNI-93's immediate, free, and total recalls are valuable tools for the diagnosis of AD.

Automated summary

The TNI-93 is a quick memory test designed for all patients, regardless of their education level. In this study, the diagnostic value of TNI-93 for patients with biologically confirmed amyloid status was assessed. The results showed that immediate, free, and total recalls of TNI-93 are valuable tools for the diagnosis of Alzheimer's disease.