Spinal Cord Stimulation for Poststroke Spasticity (SCS-PSS)

Spinal Cord Stimulation for Poststroke Spasticity: a Multicentre, Double-blind, Randomised, Sham-controlled Trial (SCS-PSS)

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

Study Overview

• Status: Not yet recruiting
• Conditions: Spasticity Post Stroke
• Intervention / Treatment: Device: Active spinal cord stimulation; Device: Sham spinal cord stimulation

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 92
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jianguang Sun; Phone Number: 010-60736388; Email: sunjianguang@pinsmedical.com
• Study Contact Backup: Name: Yifan Yang; Phone Number: 15674915048; Email: yangyifan@pinsmedical.com

Study Locations

• China
  • Beijing, China
    • China-Japan Friendship Hospital
    • Contact: Qi Wang; Phone Number: 15810619158

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: SCS Group; Active SCS	Device: Active spinal cord stimulation; 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
Active Comparator: Control Group; Sham SCS	Device: Sham spinal cord stimulation; 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	Baseline to Week 6 after randomization

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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	Day 0, Week 6, Week 12, Week 24, Year 1, and Year 2 after randomization
Proportion of Participants With an Improvement in Mean Modified Ashworth Scale Score of at Least 1 Point	A participant is defined as a responder when the mean MAS score of the Primary Target Muscle Groups decreases by at least 1 point compared with baseline. The outcome is reported as the proportion of responders at each assessment.	Day 0, Week 6, Week 12, Week 24, Year 1, and Year 2 after randomization
Change in Active and Passive Joint Range of Motion From Baseline	Active and passive range of motion are measured in degrees for movements corresponding to the assessed muscle groups. Upper-limb measurements include shoulder abduction, shoulder external rotation, elbow extension, elbow flexion, forearm supination, wrist extension, and metacarpophalangeal joint extension. Lower-limb measurements include hip extension, hip abduction, hip external rotation, knee extension, knee flexion, and ankle dorsiflexion. A greater range generally indicates better joint mobility.	Day 0, Week 6, Week 12, Week 24, Year 1, and Year 2 after randomization
Change in Fugl-Meyer Assessment Score From Baseline	The Fugl-Meyer Assessment (FMA) is used to assess motor and sensory function. The upper-limb motor score ranges from 0 to 66, and the lower-limb motor score ranges from 0 to 34. Light touch sensation is assessed at the upper arm, palm, thigh, and sole, with each site scored from 0 to 2, giving a total score of 0 to 8. Proprioception is assessed at the shoulder, elbow, wrist, thumb, hip, knee, ankle, and toe joints, with each site scored from 0 to 2, giving a total score of 0 to 16. Higher scores indicate better motor and sensory function.	Day 0, Week 6, Week 12, Week 24, Year 1, and Year 2 after randomization
Change in Functional Independence Measure Score From Baseline	The Functional Independence Measure (FIM) is used to assess functional independence. The change in total FIM score from baseline is calculated at each post-baseline assessment. A higher score indicates greater functional independence	Day 0, Week 6, Week 12, Week 24, Year 1, and Year 2 after randomization
Change in Physician Global Assessment Score From Baseline	The Physician Global Assessment (PGA) is completed by the investigator to assess overall spasticity severity and treatment response. The change in PGA score from baseline is calculated at each post-baseline assessment.	Day 0, Week 6, Week 12, Week 24, Year 1, and Year 2 after randomization
Change in 10-Meter Walk Test Performance From Baseline	The 10-Meter Walk Test (10MWT) is used to assess comfortable and fast walking speed. The change in walking time and walking speed from baseline is calculated at each post-baseline assessment. A shorter walking time or higher walking speed indicates better walking performance.	Day 0, Week 6, Week 12, Week 24, Year 1, and Year 2 after randomization
Change in EQ-5D-5L Score From Baseline	The EQ-5D-5L is used to assess health-related quality of life. The change in the EQ-5D-5L health utility index and EQ-VAS score from baseline is calculated at each post-baseline assessment. Higher scores indicate better health status.	Day 0, Week 6, Week 12, Week 24, Year 1, and Year 2 after randomization
Change in Visual Analogue Scale Score From Baseline	Spasticity-related pain is assessed using a Visual Analogue Scale (VAS) ranging from 0 to 10. The change in VAS score from baseline is calculated at each post-baseline assessment. A lower score indicates less pain.	Day 0, Week 6, Week 12, Week 24, Year 1, and Year 2 after randomization

Collaborators and Investigators

• Sponsor: Beijing Pins Medical Co., Ltd
• Collaborators: Xiangya Hospital of Central South University; Beijing Tiantan Hospital; First Affiliated Hospital, Sun Yat-Sen University; RenJi Hospital; West China Hospital; Qilu Hospital of Shandong University; Beijing Sanbo Brain Hospital; Xuanwu Hospital, Beijing; Beijing Chao Yang Hospital; The First Affiliated Hospital of Zhengzhou University; China-Japan Friendship Hospital; First Affiliated Hospital of Xinjiang Medical University; Anhui Provincial Hospital; Beijing Tsinghua Changgeng Hospital; Nanjing Brian Hospital; Peking University Aerospace Center Hospital; Second Affiliated Hospital, Zhejiang University, School of Medicine

Publications and helpful links

General Publications

• Brashear A, Gordon MF, Elovic E, Kassicieh VD, Marciniak C, Do M, Lee CH, Jenkins S, Turkel C; Botox Post-Stroke Spasticity Study Group. Intramuscular injection of botulinum toxin for the treatment of wrist and finger spasticity after a stroke. N Engl J Med. 2002 Aug 8;347(6):395-400. doi: 10.1056/NEJMoa011892.
• Rowald A, Komi S, Demesmaeker R, Baaklini E, Hernandez-Charpak SD, Paoles E, Montanaro H, Cassara A, Becce F, Lloyd B, Newton T, Ravier J, Kinany N, D'Ercole M, Paley A, Hankov N, Varescon C, McCracken L, Vat M, Caban M, Watrin A, Jacquet C, Bole-Feysot L, Harte C, Lorach H, Galvez A, Tschopp M, Herrmann N, Wacker M, Geernaert L, Fodor I, Radevich V, Van Den Keybus K, Eberle G, Pralong E, Roulet M, Ledoux JB, Fornari E, Mandija S, Mattera L, Martuzzi R, Nazarian B, Benkler S, Callegari S, Greiner N, Fuhrer B, Froeling M, Buse N, Denison T, Buschman R, Wende C, Ganty D, Bakker J, Delattre V, Lambert H, Minassian K, van den Berg CAT, Kavounoudias A, Micera S, Van De Ville D, Barraud Q, Kurt E, Kuster N, Neufeld E, Capogrosso M, Asboth L, Wagner FB, Bloch J, Courtine G. Activity-dependent spinal cord neuromodulation rapidly restores trunk and leg motor functions after complete paralysis. Nat Med. 2022 Feb;28(2):260-271. doi: 10.1038/s41591-021-01663-5. Epub 2022 Feb 7.
• Francisco GE, McGuire JR. Poststroke spasticity management. Stroke. 2012 Nov;43(11):3132-6. doi: 10.1161/STROKEAHA.111.639831. Epub 2012 Sep 13. No abstract available.
• Lorach H, Galvez A, Spagnolo V, Martel F, Karakas S, Intering N, Vat M, Faivre O, Harte C, Komi S, Ravier J, Collin T, Coquoz L, Sakr I, Baaklini E, Hernandez-Charpak SD, Dumont G, Buschman R, Buse N, Denison T, van Nes I, Asboth L, Watrin A, Struber L, Sauter-Starace F, Langar L, Auboiroux V, Carda S, Chabardes S, Aksenova T, Demesmaeker R, Charvet G, Bloch J, Courtine G. Walking naturally after spinal cord injury using a brain-spine interface. Nature. 2023 Jun;618(7963):126-133. doi: 10.1038/s41586-023-06094-5. Epub 2023 May 24.
• Creamer M, Cloud G, Kossmehl P, Yochelson M, Francisco GE, Ward AB, Wissel J, Zampolini M, Abouihia A, Berthuy N, Calabrese A, Loven M, Saltuari L. Intrathecal baclofen therapy versus conventional medical management for severe poststroke spasticity: results from a multicentre, randomised, controlled, open-label trial (SISTERS). J Neurol Neurosurg Psychiatry. 2018 Jun;89(6):642-650. doi: 10.1136/jnnp-2017-317021. Epub 2018 Jan 11.
• Gracies JM, Brashear A, Jech R, McAllister P, Banach M, Valkovic P, Walker H, Marciniak C, Deltombe T, Skoromets A, Khatkova S, Edgley S, Gul F, Catus F, De Fer BB, Vilain C, Picaut P; International AbobotulinumtoxinA Adult Upper Limb Spasticity Study Group. Safety and efficacy of abobotulinumtoxinA for hemiparesis in adults with upper limb spasticity after stroke or traumatic brain injury: a double-blind randomised controlled trial. Lancet Neurol. 2015 Oct;14(10):992-1001. doi: 10.1016/S1474-4422(15)00216-1. Epub 2015 Aug 26.
• Riva N, Mora G, Soraru G, Lunetta C, Ferraro OE, Falzone Y, Leocani L, Fazio R, Comola M, Comi G; CANALS Study Group. Safety and efficacy of nabiximols on spasticity symptoms in patients with motor neuron disease (CANALS): a multicentre, double-blind, randomised, placebo-controlled, phase 2 trial. Lancet Neurol. 2019 Feb;18(2):155-164. doi: 10.1016/S1474-4422(18)30406-X. Epub 2018 Dec 13.
• de Freitas RM, Bhatia S, Sorensen E, Verma N, Carranza E, Ensel S, Borda L, Boos A, Goldsmith J, Fisher LE, Fields DP, Powell MP, Gordon S, Balzer J, Friedlander RM, Wittenberg GF, Gerszten PC, Krakauer JW, Pirondini E, Weber DJ, Capogrosso M. Spinal cord stimulation for upper limb motor function in people with chronic post-stroke hemiparesis: a feasibility trial. Nat Med. 2026 Jun 4. doi: 10.1038/s41591-026-04435-1. Online ahead of print.

Study record dates

Study Major Dates

• Study Start (Estimated): August 6, 2026
• Primary Completion (Estimated): February 15, 2027
• Study Completion (Estimated): May 31, 2027

Study Registration Dates

• First Submitted: July 29, 2026
• First Submitted That Met QC Criteria: July 29, 2026
• First Posted (Actual): August 4, 2026

Study Record Updates

• Last Update Posted (Actual): August 4, 2026
• Last Update Submitted That Met QC Criteria: July 29, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Stroke; Randomized Controlled Trial; Spinal Cord Stimulation; Spasticity; Limb function
• Additional Relevant MeSH Terms: Neurologic Manifestations; Musculoskeletal Diseases; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Muscular Diseases; Muscle Hypertonia; Neuromuscular Manifestations; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Muscle Spasticity; Stroke
• Other Study ID Numbers: SCS-PNS0102&PINS-C2-01-53

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No