Diagnostic accuracy of the phototest for cognitive impairment and dementia in Chile

Using Cognitive Reserve to Create Norms for the TMA-93 (Relational Binding of Images)

BACKGROUND

TMA-93 examines relational binding using images. Biomarker validation has demonstrated that it is discriminative for diagnosing early AD. The effect of cognitive reserve on TMA-93 performance remains unexplored and could improve the interpretative framework for using the test.

OBJECTIVE

To study the effect of cognitive reserve on TMA-93 performance and to provide new norms for the test that include its measurement.

METHODS

Cognitively unimpaired people aged 55 and over were systematically recruited for this cross-sectional normative study in southern Spain. Age, sex, and scores on the Cognitive Reserve Questionnaire (CRQ; maximum score: 25 points) were collected, and the TMA-93 was administered (maximum score: 30 points). Percentile-based reference data that captured combinations of socio-demographics variables with significant effect on TMA-93 performance were calculated.

RESULTS

902 participants (62.5% female; age: median = 68, IQR = 61-75, range = 55-90) were included. CRQ total scores were globally low (median = 8, IQR = 5-13, range = 0-24). Cognitive reserve, including modifiable items as reading activity and intellectual gaming activity, and age mainly supported the TMA-93 total score variance. Sex seemed to have some influence in the elderly. TMA-93 total scores medians began to drop from 70-75 years old. Higher total score on the CRQ and, possibly, female sex determined a gentler slope. New norms based on these variables showed wide variations in scores for the 5th and 10th percentiles.

CONCLUSION

Visual relational binding ability depends on cognitive reserve, including modifiable items. The age-related binding deficit is buffered by higher cognitive reserve and, at older ages, by female sex.

Clinical utility of Phototest via teleneuropsychology in Chilean rural older adults

The COVID-19 pandemic has shown the need for neuropsychological care for older adults with memory complaints in different contexts, including rural areas or areas with difficult access.

Objective

This study aimed to analyze the clinical utility of the Phototest, through telemedicine, to identify mild cognitive impairment in rural older adults with memory complaints, during the COVID-19 pandemic.

Methods

We performed a cross-sectional, case-control, and clinical utility comparison of brief cognitive tests (BCTs). The sample included 111 rural elderly people with mild cognitive impairment (MCI) and 130 healthy controls from the Los Lagos region, Chile. The instruments adopted were modified Mini-Mental State Examination (MMSEm) and adapted version of the Phototest (PT) for Chile.

Results

To identify mild cognitive impairment, using a cutoff score of 27-28 points, the Phototest showed a sensitivity of 96.6% and a specificity of 81.8%; indicators superior to those of the MMSEm.

Conclusions

The Phototest is more accurate than the MMSEm in identifying cognitive alterations in rural older adults with cognitive memory complaints through telemedicine. Therefore, its use in primary care is recommended in order to perform early detection of preclinical cognitive alterations in mild cognitive impairment or neurodegenerative diseases.

Testing Visual Binding by the TMA-93 in People Aged 75 and Over

Background: TMA-93 examines relational binding using images. The test has been proven to be discriminative for diagnosing early Alzheimer’s disease by biomarkers. Norms for this test are available, but the elderly, at high risk for Alzheimer’s disease, have not yet been widely represented. Objective: To extend normative data on the TMA-93 for people aged 75 and over. Methods: An extension of the Spanish TMA-93 normative study was undertaken. Only cognitively unimpaired people aged 75 and over were included. Age, gender, and educational attainment were registered as socio-demographic variables. Using histograms analysis, median comparisons, and linear regression analysis, we selected variables that demonstrated influence on TMA-93 total scores and provided percentile-base reference data according to combinations of those variables. Results: We included 431 new participants, resulting in a total sample of 657 individuals (median age = 78, interquartile range = 76–81, range = 75–93). Percentile-base reference data stratified by a combination of age ranges (75–79, n = 428; and ≥80 years, n = 229), and educational attainment (<  first grade, n = 253; first grade, n = 209; >  first grade, n = 195) revealed that participants achieved a minimum TMA-93 total score of 26/30 at the 50th-percentile regardless of stratum. At the 10th-percentile, a maximum of 24/30 was achieved in the more educated stratum contrasting with a minimum of 19/30 in the less educated stratum. Conclusion: Although mitigated by lower levels of education, performance on the TMA-93 is widely preserved in cognitively unimpaired people aged 75 and over. The test could facilitate the screening of elderly patients with memory complaints.