Stroke is the leading cause of motor impairment acquired after 40 years. Of the affected patients, 50% do not recover active finger extension and there is no satisfactory solution for functional recovery of the grip in these patients. The use of wearable exoskeletons to improve the grip is limited by their size and cost. An alternative is the use of functional electrical stimulation of the grasping muscles, named prehension neuroprosthesis, well developed in the spinal cord injured patient. In the adult hemiplegic patient, only about ten studies concerned the functional impact of a prehension neuroprosthesis, which have shown potential to perform a correct hand opening linked with a significant functional gain. Nevertheless, one of the major problems concerns the definition of the optimal modalities to control the prehension neuroprosthesis, modalities which until now have proved unsuitable for post-stroke patients: an open-loop control with manual triggering of the neuroprosthesis (press-button type) is not suitable with daily living use; control with the contralateral upper-limb is also not suitable for everyday use where bimanual tasks are required; and finally, the use of the residual voluntary electromyographic activity of the targeted muscle limits the opening of the fingers and the reliability of the control by promoting the occurrence of spastic cocontractions of the flexors of the fingers.~In this context, the present project proposes to evaluate the functional contribution of a closed-loop controlled prehension neuroprosthesis that will restore an extension of the fingers and the thumb in order to improve the grip function.~Each patient is evaluated 5 times during visits lasting between 1h30 and 2 hours. Patients are already admitted to standard care for a period of at least 5 consecutive days in the Rehabilitation Center. The visit (Day 1) will include the patient and collect the Action Arm Research Test (ARAT) and Upper Limb Performance Assessment (ULPA) scores achieved with the inactive prehension neuroprosthesis. The visit T1 (day 2) will select the preferred control mode of the neuroprosthesis. The visit T2 (day 3) and T3 (day 4) will allow learning and training in the use of the neuroprosthesis. The visit T4 (day 5) will evaluate the functional impact of the neuroprosthesis: the patients will perform the standardized primary and secondary gripping tasks with the activated or inactivated neuroprosthesis, then the ARAT and ULPA with activated neuroprosthesis, and finally the Psychosocial Impact of Assistive Devices Scale and the Device subscale of the Quebec User Assessment of Satisfaction with Assistive Technology questionnaire will be completed. The end of the visit T4 corresponds to the end of the patient's inclusion in the research protocol.
The aim of the PREHENS-STROKE study is to propose a functional replacement device to restore grip capacities in patients with hemiparesis after stroke, unable to actively open the hand to seize objects. The main objective is to evaluate the impact of the use of a self-controlled prehension neuroprosthesis on the ability to perform a standardized grasping task, consisting of grasping, relocating and releasing a glass (palmar grasp) or a spoon (key-pinch), compared to a condition without the use of the prehension neuroprosthesis.