Restoring Hand Function in Patients with Tetraplegia by Intraneural Stimulation of Peripheral Nerves

Restoring Hand Function in Patients with Tetraplegia by Intraneural Stimulation of Peripheral Nerves

The aim of the clinical investigation is to evaluate the feasibility, in terms of efficacy and safety, of a prosthetic system, the Regrasp 1 system, based on intraneural stimulation via TIME- 4H electrodes, as an aid device for restoring hand function in tetraplegic patients.

The study involves implanting intraneural electrodes in the nerve used to open and close the hand.

Electrical stimulation will activate the forearm and hand muscles, and thus evoke movements such as opening and closing the fingers of the hand and wrist movements. Electrodes will be implanted temporarily and reversibly within the fascicles so that a more selective and therefore more effective stimulation can be determined. The electrodes will remain implanted for about 6 months.

During this period, the results of the external electrical stimulation will be analysed through experimental sessions that will take place at the Careggi University Hospital. At the end of the study, the electrodes will be removed by surgery under general anaesthesia.

Inclusion Criteria:

1. Men or women aged between 18 and 70.
2. Spinal cord injury at the C5-6 level, with complete motor paralysis (ASIA A or ASIA B).
3. Chronic injury (> 6 months), with stable clinical condition.

Exclusion Criteria:

1. Systemic infections.
2. Central and/or peripheral nervous system comorbidity.
3. Reduced joint flexibility.
4. Severe spasticity of the upper limb (mAS 3).
5. Severe denervation of forearm and hand muscles (as demonstrated by electromyography and electroneurography analysis and intraoperative neural stimulation).
6. Muscles not electrically excitable.
7. Presence of hyperalgesia or allodynia.
8. Wearers of life support devices that could be adversely affected by electromagnetic interference, such as pacemakers, implanted cardioverter defibrillators, etc.
9. Cognitive impairment.
10. Active or history of psychiatric illnesses including major depression, bipolar disorder and personality disorders (borderline or antisocial personality disorder).
11. Pregnancy.
12. History of alcohol or substance abuse.
13. Acquired brain injury with residual deficits.
14. Participation in other clinical trials.
15. Known allergies/hypersensitivity to TIME-4H electrode materials.
16. Life expectancy of less than one year.
17. Contraindications to general anaesthesia (patient refusal, severe aortic stenosis, significant pulmonary disease, etc.).