Smartphone-based assessment a reliable tool for evaluating frontotemporal lobar degeneration

Remote evaluation of frontotemporal lobar degeneration (FLTD) with the use of smartphones is feasible and reliable and may help with early detection, as reported in a study.

The study included 360 participants (mean age 54.0 years, 58.1 percent women), with 258 included in the discovery cohort and the remaining 102 in the validation cohort. All participants completed standard in-clinic measures and remotely administered North American FTLD research consortium (ALLFTD) mobile app smartphone tests. The main outcome measures were internal consistency, test-retest reliability, association of smartphone tests with criterion standard clinical measures, and diagnostic accuracy.

Of the 329 participants who had available data on disease stage, 195 were asymptomatic or had preclinical FTLD (59.3 percent), 66 had prodromal FTLD (20.1 percent), and 68 had symptomatic FTLD (20.7 percent) with a range of clinical syndromes.

The smartphone tests achieved moderate-to-excellent reliability (intraclass correlation coefficients, 0.77–0.95) and showed an association with disease severity, criterion-standard neuropsychological tests, and brain volume. The tests were able to accurately distinguish between individuals with dementia and controls (area under the curve [AUC], 0.93, 95 percent confidence interval [CI], 0.90–0.96), with a greater sensitivity to early symptoms (AUC, 0.82, 95 percent CI, 0.76–0.88) than to the Montreal Cognitive Assessment (AUC, 0.68, 95 percent CI, 0.59–0.78; p=0.01 for comparison).

Results for reliability and validity were highly similar in the discovery and validation cohorts. Notably, pathogenic variant carriers had a significantly worse performance than noncarrier family controls on 3 app tasks (eg, 2-back: β, −0.49; p<0.001) but not on a composite of traditional neuropsychological measures (β, −0.14; p=0.32).

The findings support smartphone assessments as a complementary approach to traditional in-person trial designs.