Home-use Grasp Neuroprosthesis for helping with finger opening after stroke

Inclusion CriteriA/

* Adult patient who participated in and completed the GRASP-AGAIN study and achieved functional improvement through the use of NAP.
* Motor deficit of an upper limb resulting from a single ischemic or hemorrhagic stroke, hemispheric or brainstem, confirmed by brain imaging (CT scan or MRI);
* Brain lesion occurring more than one month prior;
* Presence of at least one of the following two disabilities:

  * Inability to actively extend the long fingers (open the hand) to actively grasp an empty glass (upper and lower diameters of 7 and 6 cm respectively, height of 12 to 15 cm, weight of 125 g, identical to the material used for the Action Research Arm Test scale) with a palmar grip, without the aid of the other hand, while the subject is able to hold the glass passively in the hand;
  * Inability to actively extend the thumb to grasp the handle of a soup spoon (flat, like a key) without the aid of the other hand, using a thumb-index finger pulp-lateral grip (grasping task in the Wolf Motor Function Test), while the subject can passively hold the handle of a spoon or a key previously placed between the thumb and index finger;
* Patient receiving care within the standard healthcare pathway;
* Ability to sit in a chair and remain focused for at least 1.5 hours;
* Free, informed, and written consent signed by the participant and the investigator (no later than the day of enrollment and before any examination required for the research);
* Individual affiliated with or covered by a social security scheme

Exclusion Criteria:

* The person is in labor or breastfeeding;
* The person is pregnant, the diagnosis being guided by questioning (date of last menstrual period, desire for pregnancy, contraception) and possibly confirmed by a blood test for beta hCG;
* Musculotendinous contractures or joint stiffness of the fingers and wrist preventing passive opening of the fingers;
* Limited approach ability preventing the hand from being positioned in front of the abdomen (without contact) at the level of the midline sagittal plane, while the subject is seated;
* Paretic pain in the upper limb limiting the performance of the standardized grasping task;
* Major sensory disturbances corresponding to a Somatosensation subscore of the modified Erasmus Nottingham Sensory Assessment French version (EmNSA-F, see Appendix A) upper limb \<10/44;
* Severe aphasia with a Boston Diagnostic Severity Aphasia Examination Severity Scale score ≤ 3, see Appendix B, indicating that there may be a marked decrease in verbal fluency or ease and rapidity of comprehension, without significant limitation of expression or communication;
* Known gestural apraxia, within the limits of the subject's motor abilities (ideomotor apraxia, ideational apraxia, dressing apraxia, or reflexive apraxia);
* Unilateral spatial neglect demonstrated with the bell test (see Appendix B'), if the difference between omissions in the left and right visual fields is greater than or equal to 6;
* The extensor digitorum communis and/or extensor pollicis longus muscles cannot be stimulated with the neuroprosthesis, meaning that sufficient extension of the long fingers and/or thumb for grasping tasks is not achieved with electrical stimulation well tolerated by the patient;
* The person has a pacemaker;
* Presence of uncontrolled epilepsy;
* Presence of unstable cardiovascular disease (coronary artery disease, severe hypertension, heart failure);
* Presence of a dermatological condition contraindicating the application of surface electrodes;
* The person is participating in another research study with an ongoing exclusion period;
* The person is under legal guardianship or conservatorship;
* The person refuses to sign the consent form;
* It proves impossible to provide the person with informed consent and ensure their compliance due to impaired physical and/or psychological health.