The efficacy of a task model approach to ADL rehabilitation in stroke apraxia and action disorganisation syndrome: A randomised controlled trial

Abstract

Background: Apraxia and action disorganization syndrome (AADS) after stroke can disrupt activities of daily living (ADL). Occupational therapy has been effective in improving ADL performance, however, inclusion of multiple tasks means it is unclear which therapy elements contribute to improvement. We evaluated the efficacy of a task model approach to ADL rehabilitation, comparing training in making a cup of tea with a stepping training control condition.

Methods: Of the 29 stroke survivors with AADS who participated in this cross-over randomized controlled feasibility trial, 25 were included in analysis [44% females; mean(SD) age = 71.1(7.8) years; years post-stroke = 4.6(3.3)]. Participants attended five 1-hour weekly tea making training sessions in which progress was monitored and feedback given using a computer-based system which implemented a Markov Decision Process (MDP) task model. In a control condition, participants received five 1-hour weekly stepping sessions.

Results: Compared to stepping training, tea making training reduced errors across 4 different tea types. The time taken to make a cup of tea was reduced so the improvement in accuracy was not due to a speed-accuracy trade-off. No improvement linked to tea making training was evident in a complex tea preparation task (making two different cups of tea simultaneously), indicating a lack of generalisation in the training.

Conclusions: The clearly specified but flexible training protocol, together with information on the distribution of errors, provide pointers for further refinement of task model approaches to ADL rehabilitation. It is recommended that the approach be tested under errorless learning conditions with more impaired patients in future research.

Trial registration: Retrospectively registered at ClinicalTrials.gov on 5th August 2019 [NCT04044911] https://ichgcp.net/clinical-trials-registry/NCT04044911?term=Cogwatch&rank=1.

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1. Consort diagram showing the flow of participants through the study.

Fig 2. Object layout for simple tea at assessment.

(a) Simple and (b) Complex Tea Layout Mat to scale (80x50cm); kettle (15cm diameter) bowls & water jug (12.8cm), cups, milk and coffee (8cm), cutlery (13.7–17.7cm), sweetener (4.5cm). Coffee was used as a distractor.

Fig 3. CogWatch system setup.

a) As the patient completes tea-making with the items on the table layout, cues are presented on the “patient display” (foreground) when an error is detected (in this case non-recoverable). The healthcare professional monitors task progression via the “clinician display” (background). b) Each correct step is acknowledged by the system by displaying a visual reminder of the completed sub-action at the top of the patient display. Here, the patient has completed “Add water from jug to kettle”, “Boil water”, “Add teabag to cup”, “Add sugar”, “Add milk” and is performing the sub-action of “Add boiled water to cup”. We acknowledge The Stroke Association, UK, as the source of this figure. The individuals in this figure have given written informed consent (as outlined in the PLOS consent form) to publish their image.

Fig 4. Mapping of actions and errors to neuropsychological classification.

From left to right are the sub-actions which are performed during simple tea making, action errors which may result during performance of the sub-actions, and their relation to the neuropsychological error categories which were used for analysis. In addition to errors which were trained by the Cogwatch subsystem, 4 additional errors were identified during the assessment (in boxes with broken line borders).

Fig 5. Tea making performance.

(a) error (b) time taken for the two patient groups (Group 1: Baseline (1), Post-training (2), Post-control (3), Follow-up (4); Group 2: Baseline (1), Post-control (2), Post-training (3), Follow-up (4)). Tea making change scores (c) Recoverable and nonrecoverable errors (d) time as a function of condition. Experimental, control and follow-up scores were calculated 1–2, 2–3, 2–4 (where experimental, control and follow-up were calculated as Group1) and 2–3,1–2, 3–4 (Group 2). Statistically significant contrasts are shown across the top of (c, d).

Fig 6. Error changes.

Number of three types of non-recoverable (addition N-ADD, object substitution N-OSUB, kettle error N-KET) and six types of recoverable errors (addition N-ADD, object substitution N-OSUB, kettle error N-KET) before (dark shade bars) and after tea-making training (light shade bars). Note that only data from complete cases (n = 22) are included in this figure as error type data were not imputed.

Fig 7. Error types.

Relative proportions of the three types of non-recoverable errors (addition N-ADD, object substitution N-OSUB, kettle error N-KET in shades of green) and six types of recoverable errors (continuous perseveration R-CP, execution R-EX, recurrent perseveration R-RP, sequence R-SEQ, quantity underestimation R-QU, step omission R-SOM in shades of blue) pre and post-tea making training. Note that no non-recoverable step omission errors occurred during the pre and post-tea making sessions.

Fig 8. Complex tea making.

(a) Proportion of complex tea making errors as a function of training condition. (b) Mean change in complex tea making errors across contrasts.