Haptic technology for recovery of dexterity after stroke – HapticS

Stroke survivors often suffer manual dexterity impairments reducing their autonomy and quality of life. Recovery of dexterity is drastically suboptimal and the degree of recovery is difficult to predict. Existing therapies aim at restoring upper limb movements, but fail to target manual dexterity more specifically. Somatosensory (tactile and proprioceptive) information is key to skilled manual dexterity, however, current post-stroke therapies do not provide sensory feedback of finger movements: haptic approaches that aim at substituting somatosensory post-stroke deficits are lacking. This multi-center project aims to provide novel haptic technology that (i) enhances accuracy of quantitative dexterity measurement, (ii) provide improved prediction of post-stroke recovery of dexterity, and (iii) by generating enhanced somatosensory feedback, through haptic-dexterity tasks, deliver more efficient and targeted post-stroke neurorehabilitation of manual dexterity. The project consists of three parts:
(1) We will develop haptic technology, using vibro-tactile stimulators, and dedicated testing protocols (with the Dextrain device) to study haptic influence on multi-control components of manual dexterity (force control, timing, maximal tapping, motor sequencing and independent finger movements). The degree of haptic control, assessed by these novel quantitative measures, is expected to explain more variance in dexterity performance than conventional clinical sensory tests. Comparison between young (N=30) and older healthy controls (N=30) and stroke patients (N=30) will inform on age and stroke-related decline in ability to use haptic feedback for dexterity. Validity and intra-rater reliability of haptic measures will be established in controls and stroke patients.
(2) We will record longitudinal dexterity data in 84 stroke patients to evaluate whether haptic influence can improve the prediction of dexterity recovery at 6 months. The prediction model will also include motor, sensory and cognitive impairments, as well as degree of injury to motor and sensory tracts (assessed by brain imaging). Multi-modal brain imaging will also be used to study neural mechanisms of haptic deficits and recovery of dexterity.
(3) We will perform a proof-of-concept randomized clinical trial in 30 stroke patients on the efficacy of haptic training in the home to improve dexterity and enhance cortical excitability and inhibition, assessed with transcortical magnetic stimulation.
This project will provide haptic technology for measurement and rehabilitation of manual dexterity after stroke. Neural mechanisms of sensorimotor integration and its role for recovery will be charted. Collaboration with the Dextrain company ensures significant economic potential and impact of innovations.