Clinical validation of TAS Test automated hand motor analysis to discriminate subjective cognitive decline, mild cognitive impairment and dementia in a multidisciplinary cognitive clinic

Abstract

AbstractBackgroundGait analysis studies have shown that motor function declines across the Alzheimer’s disease (AD) continuum and may aid early detection of dementia risk. Hand movement analysis has been poorly investigated in comparison to gait but may be easier to assess using computer keyboards. TAS Test is a new automated online test of hand movements. The aim of this study was to evaluate TAS Test keyboard tapping tests compared to gold standard consensus diagnosis in a multidisciplinary team (MDT) cognitive clinic.MethodParticipants attending the ISLAND Cognitive Clinic in Tasmania, Australia underwent extensive neuropsychological, medical and MRI assessments before an MDT consensus diagnosis was formulated. They also completed 5 minutes of TAS Test keyboard tapping tests including single‐, alternate‐ and 3 step‐ key tapping tests. Motor features of frequency, rhythm, accuracy, and dwell time were extracted. Healthy controls (HC) with normal cognition also completed TAS Test. Accuracy to discriminate diagnostic groups using TAS Test motor features, adjusted for age, in ridge regression models was assessed using area under ROC curves (AUC) and compared to a null model which comprised only confounding variables.Result205 participants were recruited (mean [SD] age 69.0 [8.9] years): 91 from the Cognitive Clinic with Subjective Cognitive Decline (SCD, N = 16), Mild Cognitive Impairment (MCI, N = 40) or Dementia (N = 35) and 114 HCs. TAS Test discriminated better than null models with the following AUCs [95% CI]: SCD from HC: 0.82 [0.73‐0.91], MCI from HC: 0.78 [0.69‐0.86], Dementia from HC: 0.91 [0.86‐0.97], MCI from SCD: 0.7 [0.63‐ 0.92], Dementia from MCI: 0.82 [0.82‐0.97], all p <0.01. Hand tests were characterized by progressively slower, less rhythmic movements, with more pauses and less accuracy across the dementia continuum. Dominant hand features were more discriminatory than non‐dominant hand features.ConclusionA simple brief battery of keyboard tapping tests via the TAS Test website aids stratification of diagnostic groups. This novel hand motor approach is more accessible than gait analysis and opens new opportunities for objective motor measure in clinical and research applications. Longitudinal research is underway to assess if TAS Test can aid prediction of cognitive decline in cognitively healthy controls.