In a current first-in-human clinical trial, called STIMO, Electrical Epidural Spinal Stimulation (EES) is applied to enable individuals with chronic severe spinal cord injury (SCI) to complete intensive locomotor neurorehabilitation training. In this clinical feasibility study, EES triggered an immediate enhancement of walking function, and was integrated in an intensive neurorehabilitation program. This therapy improved leg motor control and triggered neurological recovery in individuals with severe SCI to a certain extent (Wagner et al. 2018, Kathe et al. 2022).~Concurrently, preclinical and clinical evidence demonstrated a similar recruitment of upper limb muscles through cervical spinal cord stimulation, re-triggering arm movements after paralysis. The spatial and temporal modulation of the electrical stimulation can selectively activate muscle groups towards a specific function.~Clinatec (CEA, Grenoble, France) has developed an implantable electrocorticogram (ECoG) recording device with a 64-channel epidural electrode array capable of recording electrical signals from the motor cortex for an extended period and with a high signal to noise ratio. This ECoG-based system allowed tetraplegic patients to control an exoskeleton (Clinicaltrials.gov, NCT 02550522) with up to 8 degrees of freedom for the upper limb control (Benabid et al., 2019). This device has been implanted in 4 individuals so far; one of them has been using this system both at the hospital and at home for more than 3 years.~Another ongoing clinical study: STIMO-BSI (Brain Spine Interface) (Clinicaltrials.gov: NTC04632290), is combining the EES and ECoG technology to allow leg motor control in patients with chronic SCI through the decoding of cortical signals.~In this study, the investigators will test the safety and preliminary efficacy of ECoG-controlled EES in individuals with cervical SCI and establish a direct bridge between the participants' motor intention and the spinal cord below the lesion, which could restore voluntary control of arm movements as well as promote neurological recovery when combined with neurorehabilitation.
Cervical spinal cord stimulation can elicit arm and hand movements through recruitment of proprioceptive neurons in the dorsal roots. In participants with cervical spinal cord injury, the spare roots bellow the lesion can be used to reactivate motor function. Decoding of motor intentions can be achieved through implantable electrocorticography (ECoG) devices.~In this study, the investigators will use an investigational system using ECoG signal recording over the motor cortex to drive muscle specific electrical epidural spinal cord stimulation (EES). The investigators will assess the safety and preliminary efficacy of this system in 3 participants.