Smartphone App Accurately Detects Frontotemporal Lobar Degeneration

Adam M. Staffaroni, PhD

Credit: Memory and Aging Center at Weill Institute for Neurosciences at the University of California

A new study found smartphone tests accurately detected dementia and were more adept at identifying the earliest stages of familial frontotemporal lobar degeneration (FTLD) than standard neuropsychological tests.¹ With this, the app may detect FTD in gene carriers before symptoms appear.

“This is the first study, to our knowledge, to provide analogous support for the reliability and validity of remote cognitive testing via smartphones in FTLD and preliminary evidence that this approach improves early detection relative to traditional in-person measures,” wrote investigators, led by Adam M. Staffaroni, PhD, from the Memory and Aging Center at Weill Institute for Neurosciences at the University of California, in San Francisco.

Frontotemporal lobar degeneration, characterized by impairment in behavior, cognition, language, and motor functioning, is the most common form of dementia for individuals under age 60.

The degeneration has 3 main variants, 1 causing dramatic personality shifts which can appear as a lack of empathy, apathy, impulsivity, compulsive eating, and socially and sexually inappropriate behavior. Another variant impacts movement and a third affects speech, language, and comprehension.² Sometimes, FTD can trigger bursts of visual creativity, but only in rare cases.

“Most FTD patients are diagnosed relatively late in the disease, because they are young, and their symptoms are mistaken for psychiatric disorders,” said senior investigator Adam Boxer, MD, PhD, from UCSF Department of Neurology, in a press release. “We’ve heard from families that they often suspect their loved one has FTD long before a physician agrees that is the diagnosis.”

However, because this type of degeneration is relatively rare, many standard neuropsychological tests are not good at detecting early-stage disease.¹

Many barriers exist in conducting FTLD trials due to how expensive and behavioral and motor impairments can make frequent in-person trial visits a burden. Due to the rarity of the disease, global recruitment is needed to create a larger sample.

With hopes of removing barriers and eliminating in-person visits, a study assessed how well a smartphone app could screen for FTLD. Investigators sought to assess the reliability and validity of cognitive measures in the smartphone app.

Participants were enrolled through 18 centers of a North American FTLD research consortium. The team looked for the main outcomes of internal consistency, test-retest reliability, association of smartphone tests with criterion standard clinical measures, and diagnostic accuracy.

The study included 360 participants aged ≥ 18 years (mean age: 54 years; 58.1% women) who were divided into 2 cohorts: discovery (n = 258) and validation (n = 102). For 329 participants with available disease stage data, 59.3% were asymptomatic or had preclinical FTLD, 20.1% had prodromal FTLD, and 20.7% had symptomatic FTLD. They also studied the app in older individuals without functional impairment, recruited from the UCSF Brain Aging Network for Cognitive Health.

From January 10, 2019, to July 31, 2023, participants performed smartphone application-based executive functioning tasks and an associative memory task 3 times over 2 weeks. The app, ALLFTD-mApp, included cognitive, motor, and speech tasks, as well as 6 cognitive tests developed by Datacubed Health.

“We developed the capability to record speech while participants engaged with several different tests,” Staffaroni said in the press release.² “We also created tests of walking, balance, and slowed movements, as well as different aspects of language.”

The team found the validity of the smartphone tests was supported by their associations with disease severity, established neuropsychological tests, and brain volume.¹ Moreover, the smartphone tests accurately distinguished participants with dementia and controls (area under the curve [AUC], 0.93; 95% confidence interval [CI], 0.90 to 0.96) with greater sensitivity to early symptoms (AUC, 0.82; 95% CI, 0.76 to 0.88]) than the Montreal Cognitive Assessment (AUC, 0.68; 95% CI, 0.59 to 0.78) (comparison, −2.49; 95% CI, −0.19 to −0.02; P = .01).

They found smartphone cognitive tests in 2 cohorts were reliable within a single test (internally consistent) and across repeated assessments (test-retest reliability).

Limitations the investigators highlighted included the validation analyses focusing on participants’ initial task exposure rather than repeated measurements, as well as not being able to generalize the sample to the general population.

“Eventually, the app may be used to monitor treatment effects, replacing many or most in-person visits to clinical trials’ sites,” Staffaroni said.²

^References

1. ^{Staffaroni AM, Clark AL, Taylor JC, et al. Reliability and Validity of Smartphone Cognitive Testing for Frontotemporal Lobar Degeneration. JAMA Netw Open. 2024;7(4):e244266. Published 2024 Apr 1. doi:10.1001/jamanetworkopen.2024.4266}
2. ^{App may pave way to treatments for no. 1 dementia in under-60s. EurekAlert! April 1, 2024. https://www.eurekalert.org/news-releases/1039508. Accessed April 4, 2024.}