Spinal Cord Injury Epidural Stimulation


About this study

This is a feasibility study to test the use of epidural stimulation to restore volitional function previously lost due to spinal cord injury. Previous studies conducted in animal models, performed elsewhere and here at Mayo Clinic, have shown that direct electrical stimulation of the spinal cord increases the excitability of spared neuronal connections within the site of injury, thereby enhancing signal transmission and allowing recovery of previously lost volitional function. Recently, epidural electrical stimulation of the lumbosacral spinal cord in four individuals with spinal cord injury (SCI) has restored motor and autonomic function below the level of injury. Despite positive results, further translational research is needed to validate these findings. The goal of this proposal is to perform epidural stimulation to restore volitional function in patients with SCI. In two patients, we will implant an epidural stimulator onto the dorsal aspect of the lumbosacral spinal cord dura mater. Patients will undergo a structured program of daily physical rehabilitation, treadmill step training, and epidural stimulation to recover motor, sensory, and autonomic function.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  • Stable medical condition without *cardiopulmonary disease or *dysautonomia that would contraindicate standing or stepping with body weight support training
  • No current anti-spasticity medication regimen
  • Non-progressive spinal cord injury between the vertebral levels of C7 & T10
  • American Spinal Injury Association grading scale of A or B
  • Sensory evoked potentials are either not present or have a bilateral delay
  • Segmental reflexes remain functional below the lesion
  • At least 2-years post-injury.

Exclusion Criteria:

  • Pregnancy at time of enrollment
  • Failure to obtain consent
  • Prisoners
  • Children (age less than 21)
  • Any patient identified as unsuitable for this protocol by the Mayo study team
  • Skeletal fracture
  • Osteoporosis with Dual-energy X-ray absorptiometry (DEXA) t score ≤-3.5
  • Uncontrolled urinary tract infections
  • Presence or history of frequent decubitus ulcers
  • Clinical depression
  • Drug abuse
  • Painful musculoskeletal dysfunction, unhealed fracture, contracture, pressure sore, or urinary tract infection that might interfere with stand or step training
  • Current anti-spasticity medication regimen
  • Voluntary motor response present in leg muscles
  • Volitional control during voluntary movement attempts in leg muscles as measured by electromyography (EMG) activity
  • Brain influence on spinal reflexes as measured by EMG activity
  • Recordable motor evoked potential in the lower limbs with transcranial magnetic stimulation
  • Implanted cardiac pacemaker
  • Implanted defibrillator
  • Other implanted metallic or active body worn medical electronic device such as an insulin pump
  • *Cardiopulmonary disease that would result in exclusion from the study will be defined as clinically diagnosed chronic obstructive pulmonary disease, cardiac failure, and heart arrhythmia that would contraindicate sudden changes in body position such as sit-to-stand and stepping
  • *Excessive and uncontrolled autonomic dysreflexia characterized by symptomatic hypotension, light headedness and hypertension, flushing and bradycardia. Additionally blood pressure monitoring will be available at all times during rehabilitation and assessment times.

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Kristin Zhao, Ph.D.

Closed for enrollment

Contact information:

Tyson Scrabeck CCRP



More information


  • Epidural electrical stimulation (EES) of the spinal cord has been shown to restore function after spinal cord injury (SCI). Characterization of EES-evoked motor responses has provided a basic understanding of spinal sensorimotor network activity related to EES-enabled motor activity of the lower extremities. However, the use of EES-evoked motor responses to guide EES system implantation over the spinal cord and their relation to post-operative EES-enabled function in humans with chronic paralysis attributed to SCI has yet to be described. Herein, we describe the surgical and intraoperative electrophysiological approach used, followed by initial EES-enabled results observed in 2 human subjects with motor complete paralysis who were enrolled in a clinical trial investigating the use of EES to enable motor functions after SCI. The 16-contact electrode array was initially positioned under fluoroscopic guidance. Then, EES-evoked motor responses were recorded from select leg muscles and displayed in real time to determine electrode array proximity to spinal cord regions associated with motor activity of the lower extremities. Acceptable array positioning was determined based on achievement of selective proximal or distal leg muscle activity, as well as bilateral muscle activation. Motor response latencies were not significantly different between intraoperative recordings and post-operative recordings, indicating that array positioning remained stable. Additionally, EES enabled intentional control of step-like activity in both subjects within the first 5 days of testing. These results suggest that the use of EES-evoked motor responses may guide intraoperative positioning of epidural electrodes to target spinal cord circuitry to enable motor functions after SCI. Read More on PubMed
  • Spinal sensorimotor networks that are functionally disconnected from the brain because of spinal cord injury (SCI) can be facilitated via epidural electrical stimulation (EES) to restore robust, coordinated motor activity in humans with paralysis. Previously, we reported a clinical case of complete sensorimotor paralysis of the lower extremities in which EES restored the ability to stand and the ability to control step-like activity while side-lying or suspended vertically in a body-weight support system (BWS). Since then, dynamic task-specific training in the presence of EES, termed multimodal rehabilitation (MMR), was performed for 43 weeks and resulted in bilateral stepping on a treadmill, independent from trainer assistance or BWS. Additionally, MMR enabled independent stepping over ground while using a front-wheeled walker with trainer assistance at the hips to maintain balance. Furthermore, MMR engaged sensorimotor networks to achieve dynamic performance of standing and stepping. To our knowledge, this is the first report of independent stepping enabled by task-specific training in the presence of EES by a human with complete loss of lower extremity sensorimotor function due to SCI. Read More on PubMed
  • We report a case of chronic traumatic paraplegia in which epidural electrical stimulation (EES) of the lumbosacral spinal cord enabled (1) volitional control of task-specific muscle activity, (2) volitional control of rhythmic muscle activity to produce steplike movements while side-lying, (3) independent standing, and (4) while in a vertical position with body weight partially supported, voluntary control of steplike movements and rhythmic muscle activity. This is the first time that the application of EES enabled all of these tasks in the same patient within the first 2 weeks (8 stimulation sessions total) of EES therapy. Read More on PubMed