A simple, automated, speech‐based and AI‐enhanced screener for mild cognitive impairment and amyloid beta positivity

Abstract

AbstractBackgroundVocal and linguistic changes in Alzheimer’s dementia have been documented. The current study assesses whether a fully automated speech‐based artificial intelligence (AI) system can detect early clinical impairment and amyloid positivity, which characterise the earliest stages of Alzheimer’s disease (AD).MethodTwo studies were completed in the UK and USA: AMYPRED‐UK (NCT04828122) and AMYPRED‐US (NCT04928976). 200 participants with established amyloid beta (Aβ) and clinical diagnostic status (97 Aβ+, 103 Aβ‐ from prior PET scan or CSF tests; 94 cognitively unimpaired (CU), 106 with mild cognitive impairment (MCI) or mild AD) were recruited and completed automated assessments with the Automatic Story Recall Task (ASRT) either in‐clinic or via telemedicine appointment. The AI text‐pair evaluation model ParaBLEU produced vector‐based representations of the abstract, generalized patterns that differed between the original story text and transcribed retellings. These were fed into logistic regression models trained with tournament leave‐pair‐out cross‐validation analysis to predict Aβ status and MCI/mild AD. Potential benefits of screening using the ASRT system were examined via simulation, including: (1) identifying MCI in primary care, and (2) reducing the number of PET scans required in clinical research studies and trials.ResultUsing an average of only 6.56 minutes of speech per participant, the ASRT system predicted Aβ positivity in the full sample (area under the receiver operating characteristic curve (AUC) = 0.77) and in diagnostic subsamples (MCI/mild AD: AUC = 0.82; CU: AUC = 0.71), as well as MCI/mild AD (AUC = 0.83) in the full sample. Simulation indicated that screening with the ASRT system could: (1) increase correct (+8.5%) and reduce incorrect referrals (‐59.1%) compared with the Mini‐Mental State Exam; and (2) enrich samples for Aβ positivity prior to PET scan (‐35.3% and ‐35.5% fewer scans required in MCI and CU individuals, respectively).ConclusionWith the first disease‐modifying treatment for AD now available, there is an urgent need for improved screening to identify individuals at risk for AD dementia. The ASRT system is a brief, effective, automated, speech‐based cognitive assessment offering scalable screening for MCI/mild AD and amyloid beta biomarker positivity.