In what Swiss scientists has described as a breakthrough, personalised epidural electrical stimulation (EES) restored independent motor movements in three patients with complete sensorimotor paralysis hours after therapy began, data from the ongoing STIMO clinical trial showed.
Within a single day, spinal cord stimulation programmes enabled these patients to stand, walk, cycle, swim, and control their trunk movements, said Dr Jocelyne Bloch of Lausanne University Hospital in Switzerland, and Grégoire Courtine, PhD, of the Swiss Federal Institute of Technology in Lausanne, the co-authors of the research published in Nature Medicine.
The study used technology specifically developed to restore motor function, zeroing in on the dorsal roots involved in leg and lower trunk movements, Bloch and Courtine said.
“Our breakthrough here is the longer, wider implanted leads with electrodes arranged in a way that corresponds exactly to the spinal nerve roots,” Bloch said. “That gives us precise control over the neurons regulating specific muscles.”
The new, soft implanted leads are surgically placed directly on the spinal cord, underneath the vertebrae. The technology relies on specialised software that “allows us to model the spinal cord so it’s very easy for physical therapists and patients to configure an activity-dependent stimulation programme”, Courtine said. By clicking a simple device or a tablet, users can choose what activity they want to perform.
Participants in the first-in-man study included three people, 29 to 41 years old, who had suffered traumatic thoracic spinal cord injury years earlier and complete sensorimotor paralysis. After leads were implanted, all patients could step on a treadmill, though gait patterns were awkward at first.
Within days, all three study participants could take as many as 300 steps independently with body support. One participant, Michel Roccati, said he could walk with body support 11 days after the procedure, and that he could feel his body touching the ground and his muscles contracting when he walked.
Because of how the technology is designed, patients can perform their training exercises at home or outdoors. “I’ve been through some pretty intense training in the past few months, and have set myself a series of goals,” Roccati said. “I can now go up and down stairs, and I hope to be able to walk one kilometre by this spring.”
Historically, EES has been delivered using repurposed technologies that were designed to alleviate pain, Courtine pointed out. These technologies used electrodes that targeted the dorsal column, but recovering motor functions requires targeting the dorsal roots, he said.
Whether the technology will work in other patients, including older people, is not yet known. The researchers are working with Onward Medical, a medical technology company, to further study and develop the approach.
Study details
Activity-dependent spinal cord neuromodulation rapidly restores trunk and leg motor functions after complete paralysis
Andreas Rowald, Salif Komi, , Grégoire Courtine et al.
Abstract
Epidural electrical stimulation (EES) targeting the dorsal roots of lumbosacral segments restores walking in people with spinal cord injury (SCI). However, EES is delivered with multielectrode paddle leads that were originally designed to target the dorsal column of the spinal cord. Here, we hypothesised that an arrangement of electrodes targeting the ensemble of dorsal roots involved in leg and trunk movements would result in superior efficacy, restoring more diverse motor activities after the most severe SCI. To test this hypothesis, we established a computational framework that informed the optimal arrangement of electrodes on a new paddle lead and guided its neurosurgical positioning. We also developed software supporting the rapid configuration of activity-specific stimulation programs that reproduced the natural activation of motor neurons underlying each activity. We tested these neurotechnologies in three individuals with complete sensorimotor paralysis as part of an ongoing clinical trial (www.clinicaltrials.gov identifier NCT02936453). Within a single day, activity-specific stimulation programs enabled these three individuals to stand, walk, cycle, swim and control trunk movements. Neurorehabilitation mediated sufficient improvement to restore these activities in community settings, opening a realistic path to support everyday mobility with EES in people with SCI.
STIMO Clinical trial details
STIMO: Epidural Electrical Simulation (EES) With Robot-assisted Rehabilitation in Patients With Spinal Cord Injury. (STIMO)
Jocelyne Bloch, Ecole Polytechnique Fédérale de Lausanne. Foundation Wings For Life
STIMO is a First-in-Man (FIM) study to confirm the safety and feasibility of a closed-loop Epidural Electrical Stimulation (EES) in combination with overground robot assisted rehabilitation training for patients with chronic incomplete spinal cord injury (SCI).
Patients will participate during 8-12 months, during which there will be:
• Pre-implant evaluations (6-8 weeks)
• Device implantation and stimulation optimization (6-8 weeks)
• Overground rehabilitation training with EES (5-6 months). In the period after implantation, participants need to be present for testing and training, 4 days per week at the CHUV University Hospital in Lausanne (lodging can be provided). It is possible to complement the neuro-rehabilitative training at CHUV with training outside the rehabilitation room by making use of the Home-use system.
At the end of the protocol, the study aims to make the patients walk better and faster. As this is the first study of its kind, success is not guaranteed. However, the potential benefits outweigh the potential risks.
An optional extension of the study up to 3 years is offered. During this period, the patient can continue the training with the Home-use system.
The study consists of two phases:
A. Main study
The main study lasts about 8-12 months for each individual participant, from signing informed consent to the final test in the study This period can be divided into 3 distinct phases:
• Pre-implant: about 6-8 weeks from informed consent to implant. During this phase, patient will participate during a total of 6 distinct days of evaluations, of which 5 days in Lausanne and 1 day at the assessment center in Zurich. The patient will also participate to 3 weeks of pre-implantation training in a Body Weight Support (BWS) system.
• Implant and stimulation optimisation: about 6-8 weeks, including the implantation of the epidural lead and the neurostimulator. In this phase, the optimal stimulation parameters will be determined for the flexing and stretching of both legs. During this period, participants need to be present at the CHUV University Hospital in Lausanne 4-5 days per week (lodging can be provided).
• Rehabilitation training and final evaluation: 4 days per week of rehabilitation training during a period of 5 months, followed by a final evaluation lasting 4 days in Lausanne and 1 day in Zurich. In this phase, the patients receive intensive overground rehabilitation training using a body weight support device in combination with EES, with the aim of significantly improving their walking capabilities. During this period, participants need to be present at the CHUV University Hospital in Lausanne (lodging can be provided) 4 days per week.
Once the patient has shown the ability to stand or walk safely without robotic assistance, he/she is offered the possibility to complement his/her neuro-rehabilitative training using EES outside the robotic environment and rehabilitation room by making use of the Home-use system.
B. Optional study extension (3 years)
The patient has the possibility to continue his/her neuro-rehabilitative training with the home-use system for an additional period of 3 years after the end of clinical rehabilitation period. During this period, evaluation measures and technical check-ups are made at regular time points. The patient is contacted monthly to ensure a normal training conduct and a safety follow-up.
At the end of the protocol, the study aims to make the patients walk better and faster. Improvements are quantified through pre-defined measures assessed prior to implant and at the end of the main study as well as at regular time points during the optional study extension.
As this is the first study of its kind, success is not guaranteed. However, the potential benefits outweigh the potential risks.
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