Epidural electrical stimulation facilitates motor recovery in spinal cord injury involving the conus medullaris: A case study

Background: Emerging research increasingly supports that epidural spinal cord electrical stimulation (EES) combined with neurorehabilitation can improve motor recovery in spinal cord injury (SCI) subjects. Patients with lesions involving the medullary cone may be challenging to treat with this approach, probably due to potential peripheral nervous system damage, leaving the open question of whether this large population may benefit from EES. Methods: A T11–T12 SCI patient, with medullary cone involvement, underwent EES implant in a clinical trial (NCT05926843). During three months of testing, we determined optimal stimulation protocols for improving isolated movements and integrated them to reinstate independent walking with a walker. Findings: EES substantially boosted hip flexor, spinal erector, and abdominal muscle contraction, improving the patient's performance in isolated movements. Over three months of combining continuous subthreshold EES with personalized rehabilitation, the patient progressed from being unable to walk to overground ambulation using a two-wheeled walker and bilateral knee and foot orthoses. At the time of hospital discharge, the patient managed to cover 58 m in the 6-min walking test and completed the 10-meter walking test in 40.29 s. Six months after EES implant, the patient was able to walk independently for 1 km with a walker. Conclusions: These results underscore the potential of neurorehabilitation protocols integrating EES also for patients with medullary cone lesions and pave the way for new rehabilitation prospects. Funding: This work was funded by Università Vita-Salute San Raffaele, Boston Scientific Spa, Fondazione Cariplo, Bertarelli Foundation, and the Ministry of University and Research (MUR).