Spinal Cord Stimulation for Poststroke Spasticity

Beijing Pins Medical Co., Ltd92 enrolled

Overview

The goal of this clinical trial is to learn whether spinal cord stimulation (SCS) is effective in treating post-stroke spasticity in adults. It will also evaluate the safety of the implanted SCS system. The main questions it aims to answer are: 1. Does active SCS reduce limb spasticity compared with sham stimulation? 2. What device-related problems do participants experience during the study? All participants receive the same implantation and programming procedures,but no therapeutic stimulation(0 mA) for sham SCS group duringthe first 6 weeks after randomization. Participants will: 1. Have an SCS system surgically implanted 2. Be randomly assigned to receive active SCS or sham SCS for 6 weeks 3. After completion of the 6-week randomized comparison period, active stimulation will be initiated for all participants. 4. Attend a post-operative visit within 3 to 7 days after surgery for device activation or sham activation, programming, safety checks, and study assessments 5. Attend follow-up visits for study assessments at approximately 6, 12, 24 weeks, 1 year and 2 years after randomization 6. Complete assessments of muscle spasticity, joint range of motion, motor function, walking ability, daily functioning, pain, and quality of life 7. Report any medical problems or device-related problems during the study

Post-stroke spasticity is a common disabling complication of ischemic or hemorrhagic stroke. It can lead to abnormal muscle tone, restricted joint movement, impaired motor function, pain, and reduced independence in daily activities. Current treatments include rehabilitation therapy, oral antispastic medications, and botulinum toxin injections, but some patients continue to have clinically significant spasticity despite these treatments. Spinal cord stimulation (SCS) is a neuromodulation technique that delivers electrical stimulation to the spinal cord and may help regulate abnormal spinal motor circuits and reduce spasticity. Previous exploratory studies have suggested that SCS may reduce limb spasticity and improve muscle strength, motor coordination, and functional movement after stroke. However, the available evidence is mainly based on small or exploratory studies, and the safety and efficacy of SCS for post-stroke spasticity have not yet been confirmed in a large, randomized, sham-controlled clinical trial. Therefore, a well-designed controlled study is needed to determine whether the observed improvements are caused by active SCS and to further evaluate device-related safety. The Spinal Cord Stimulation for Post-Stroke Spasticity study (SCS-PSS study) is a prospective, multicenter, double-blind, randomized, sham-controlled clinical trial designed to evaluate the safety and efficacy of an implanted SCS system for adults with post-stroke spasticity. The study will enroll 92 participants with stable unilateral upper- or lower-limb spasticity after ischemic or hemorrhagic stroke who have not achieved their treatment goals with previous treatments. All participants will undergo implantation of an SCS system and will then be randomized in a 1:1 ratio to receive either active SCS or sham SCS during the first 6 weeks after randomization. Participants will attend a postoperative visit within 3 to 7 days for active or sham device activation, programming, safety assessment, and study evaluations. At 6 weeks after randomization, all participants will receive active stimulation and will continue follow-up through 24 weeks. In addition, they will undergo long-term follow-up for up to 2 years to further evaluate the durability of treatment effects and the long-term safety of the implanted SCS system. The primary outcome is the change from baseline to 6 weeks after randomization in the mean Modified Ashworth Scale score of primary target muscle groups. Additional outcomes include joint range of motion, motor function, walking ability, functional independence, pain, quality of life, adverse events, serious adverse events, and device deficiencies.

Interventions

Active spinal cord stimulationDEVICE

Participants will receive therapeutic electrical stimulation through the implanted spinal cord stimulation system beginning on Day 0, defined as the day of active or sham activation within 3-7 days after surgery. An individualized SCS programming strategy will be used. Initial stimulation parameters will include a frequency of 40-60 Hz, a pulse width of 200-300 μs, and a low starting amplitude that will be gradually increased according to participant tolerance. For participants with concomitant conditions such as pain, the stimulation frequency may be increased as clinically appropriate. Intermittent stimulation will be preferred, and electrode contact combinations will be individually selected. Active stimulation will continue through the 24-week follow-up

Sham spinal cord stimulationDEVICE

Participants will undergo the same implantation and programming procedures. On Day 0, the implanted system will be turned on, but the stimulation amplitude will be set to 0 mA so that no effective electrical stimulation is delivered during the 6-week randomized comparison period. After completion of the Week 6 assessment, participants will receive active SCS using the same individualized programming principles as the Active SCS Group. Active stimulation will continue through the 24-week follow-up.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 75 Years

Medical Language ↔ Plain English

Inclusion Criteria: 1. Aged ≥18 years and \<75 years, regardless of sex; 2. Diagnosed with ischemic or hemorrhagic stroke, with unilateral or single-limb motor dysfunction persisting for at least 6 months; 3. The primary brain lesion and its underlying cause are clinically stable; 4. Presence of unilateral upper- or lower-limb spasticity, with a Modified Ashworth Scale (MAS) grade of ≥2 in at least two muscle groups of the affected limb; 5. Post-stroke limb dysfunction has not reached the treatment goal despite previous interventions, such as physical therapy and oral medications, and the participant's condition has shown no recent improvement; 6. The type and dose of existing rehabilitation therapy and oral antispastic medications must remain unchanged during the study; 7. Willing and able to complete all study visits and procedures; 8. Able to understand the study and provide written informed consent. Exclusion Criteria: 1. Any contraindication to spinal cord stimulation surgery; 2. Uncontrolled refractory epilepsy; 3. Presence of tonic spasticity, such as decorticate rigidity or decerebrate rigidity; 4. Poorly controlled severe psychiatric or cognitive impairment, defined as a Beck Depression Inventory-II score \>25 or a Mini-Mental State Examination score \<24; 5. Active systemic infection; 6. Presence of an implanted neurostimulator or drug delivery system; 7. Botulinum toxin treatment within 4 months before enrollment; 8. Plans to initiate any new treatment during the study that may affect limb movement, including chemical denervation therapies (such as botulinum toxin), oral antispastic medications, surgical procedures (such as peripheral neurotomy or contralateral C7 nerve transfer), or other physical therapy interventions; 9. Pregnancy, breastfeeding, or planned pregnancy during the study; 10. The participant or family is unable or unwilling to participate in long-term SCS treatment management; 11. Participation in another clinical study within 4 weeks before signing informed consent; 12. Any other condition that, in the investigator's judgment, makes the individual unsuitable for participation in the study.

Outcomes

Primary Outcomes

Change in Mean Modified Ashworth Scale Score of the Primary Target Muscle Groups From Baseline to Week 6

The primary outcome is the change in the mean Modified Ashworth Scale (MAS) score of the Primary Target Muscle Groups from baseline to Week 6. The Primary Target Muscle Groups are selected from a upper or lower limb before treatment and must include at least two muscle groups. For the upper limb, eligible muscle groups include the shoulder adductors, shoulder internal rotators, elbow flexors, elbow extensors, forearm pronators, wrist flexors, and finger flexors. For the lower limb, eligible muscle groups include the hip flexors, hip adductors, hip internal rotators, knee flexors, knee extensors, and ankle plantar flexors. For analysis, the original MAS grades are converted to a 0-5 numerical scale, with grade 1+ converted to 2 and grades 2, 3, and 4 converted to 3, 4, and 5, respectively. The mean MAS score is calculated across the selected Primary Target Muscle Groups. Change is calculated as the Week 6 mean MAS score minus the baseline mean MAS score.

Time frame: Baseline to Week 6 after randomization

Secondary Outcomes

Change in Modified Ashworth Scale Scores of the Primary Target Muscle Groups From Baseline

Change in MAS of the primary target muscle groups from baseline to day 0, week 6, week 12, week 24, 1 year and 2 years after randomization