Step by Step: Kinematics of the Reciprocal Trail Making Task Predict Slowness of Activities of Daily Living Performance in Alzheimer’s Disease

Abstract

Dementia impairs the ability to perform everyday activities. Reduced motor capacity and executive functions as well as loss of memory function and forms of apraxia and action disorganization syndrome can be reasons for such impairments. In this study, an analysis of the hand trajectories during the sequential movements in an adapted version of the trail making task, the reciprocal trail making task (RTMT), was used to predict performance in activities of daily living (ADL) of patients suffering from mild cognitive impairment and dementia. 1 patient with dementia of the Alzheimer’s type and 15 healthy, age-matched adults were tested in the standardized ADL of tea making and document filing. The characteristics of the kinematic performance in the RTMT were assessed, and models of multiple linear regression were computed to predict the durations of the ADL. Patients showed increased trial durations (TDs) in the ADL (Cohen’s d: tea making 1.64, document filing 1.25). Parameters and explained variability differed across patients and control as well as between different activities. The models for the patient sample were stronger and particularly high for the document filing task for which kinematics explained 71% of the variance (Radjusted2: tea making 0.62, document filing 0.71; both tasks combined patients 0.55, controls 0.25). The most relevant factors for the models were the TD and a parameter characterizing movement fluency and variability (“movement harmonicity”) in the RTMT. The models of multiple linear regression suggested that the patients’ activity of daily living performance was limited by cognitive demands, namely, identifying the varying targets during sequencing and the healthy controls’ performance by their motor capacity. Such models could be used to estimate the severity of ADL impairments in patients.

Reach-to-grasp kinematics and kinetics with and without visual feedback in early-stage Alzheimer’s disease

“…The movement harmonicity is an indicator of movement harmonicity. The values of movement harmonicity closer to 0 indicate more harmonic movements [ 46 ]. Minimum-jerk trajectory describes ideal trajectories potentially existing in any target-oriented hand motions according to the minimum-jerk principle.…”

An Explorative Note on Apraxia Tests

“…In this study we examined the scores of three apraxia tests: hand gestures, finger gestures, and pantomime ( 15 ). We further applied a test on maximum motor capacity and an abstract sequencing task ( 16 ), thought to be predominantly limited by its cognitive demands. The computed principal component analysis revealed the possibility of two latent components in the applied tests in both samples: the “motor” component and the “cognitive” component (please see Limitations ).…”

“…Taking that a part of the RTMT is visually searching digits, the cognitive component could also be a visual component—but only in the control sample. This could be caused by healthy controls realizing the linear increment of the values in the RTMT [searching a defined value while patients would be exploring, see ( 16 )]. Nevertheless, the strong association of Hand and Finger and RAT supports the dependence of both imitation tasks on motor capacity.…”

“…Eleven patients diagnosed with dementia of the Alzheimer's typewith an age of 74.6a ± 7.6a (3 male, 8 female) and a Mini Mental State Examination score of 23.6 ± 2.9 (range: 18–28) and a control sample of 15 healthy, age-matched controls subjects (age: 71.5a ± 6.2a; 5 male, 10 female; Table 2 ) were assessed with the apraxia tests proposed by Goldenberg ( 15 ) (Figures 1 – 3 ), a reciprocal aiming task and an abstract sequencing task (reciprocal trail making task) proposed and described by Gulde ( 16 ) (see Table 1 ). The apraxia tests consisted of 10 imitations of meaningless finger gestures (max.…”

“… 1 Age related effects in the patient sample were not considered, since it would have further led to including disease onset and progression, which are not quantifiable in a satisfactory way. Further, RTMT was controlled for the maximum motor capacity in the control sample by a regression leading to , since healthy elderly show dependence of RTMT on the RAT performance ( 16 ). …”