Fully Implantable Peripheral Nerve Stimulation for Hemiplegic Shoulder Pain: A Multi-Site Case Series With Two-Year Follow-Up.

OBJECTIVE: To explore the feasibility and safety of a single-lead, fully implantable peripheral nerve stimulation system for the treatment of chronic shoulder pain in stroke survivors. PARTICIPANTS: Participants with moderate to severe shoulder pain not responsive to conservative therapies for six months. METHODS: During the trial phase, which included a blinded sham introductory period, a percutaneous single-lead peripheral nerve stimulation system was implanted to stimulate the axillary nerve of the affected shoulder. After a three-week successful trial, participants received an implantable pulse generator with an electrode placed to stimulate the axillary nerve of the affected shoulder. Outcomes included pain, pain interference, pain-free external rotation range of motion, quality of life, and safety. Participants were followed for 24 months. RESULTS: Twenty-eight participants underwent trial stimulation and five participants received an implantable pulse generator. The participants who received the implantable generator experienced an improvement in pain severity (p = 0.0002). All five participants experienced a 50% or greater pain reduction at 6 and 12 months, and four experienced at least a 50% reduction at 24 months. There was an improvement in pain interference (p < 0.0001). There was an improvement in pain-free external ROM (p = 0.003). There were no serious adverse events related to the device or to the procedure. CONCLUSIONS: This case series demonstrates the safety and efficacy of a fully implantable axillary PNS system for chronic HSP. Participants experienced reduction in pain, reduction in pain interference, and improved pain-free external rotation ROM. There were no serious adverse events associated with the system or the procedure.

The Effect of Peripheral Nerve Stimulation on Shoulder Biomechanics: A Randomized Controlled Trial in Comparison to Physical Therapy.

OBJECTIVE: To establish the effects on shoulder biomechanics from a peripheral nerve stimulation (PNS) treatment compared to physical therapy (PT) in stroke survivors with chronic hemiplegic shoulder pain. DESIGN: Single-site, pilot, randomized controlled trial for adults with chronic shoulder pain after stroke. Participants were randomized to receive a 3-week treatment of single-lead PNS or physical therapy (PT). The outcomes included isometric shoulder abduction strength, pain-free shoulder external rotation range of motion (ROM), delay in initiation and termination of shoulder abduction electromyogram (EMG) activity, and the Fugl-Meyer Motor Assessment (upper extremity section). Outcomes were measured at baseline, and at weeks 1, 4, 12, and 16. RESULTS: Twenty-five participants were recruited, 13 to PNS and 12 to PT. There were significant improvements for both PNS and PT in maximum isometric shoulder abduction strength, pain-free external rotation ROM, and Fugl-Meyer Motor Assessment. There were no significant changes in delay of initiation or termination of deltoid EMG with either treatment. CONCLUSIONS: Both PNS and PT are capable of improving shoulder biomechanics in those with HSP, though changes in biomechanics alone do not account for the greater pain relief associated with PNS than PT.

Fully implantable peripheral nerve stimulation for the treatment of hemiplegic shoulder pain: a case report.

This case report describes the first participant treated with a fully implantable, single-lead peripheral nerve stimulation system for refractory hemiplegic shoulder pain. During the 6-wk trial stage, a temporary lead was placed percutaneously near the terminal branches of the axillary nerve to the deltoid. The primary outcome measure was the Brief Pain Inventory-Short Form Question 3, a 0-10 pain numeric rating scale. The participant experienced 75% pain reduction and proceeded to the implantation stage, where he received a single-lead, implantable pulse generator. After 3 wks, the participant became pain-free. However, 7 wks after implantation, the system was turned off because of an unrelated acute medical illness. Hemiplegic shoulder pain reemerged with a Brief Pain Inventory-Short Form Question 3 score of 9. After 11 wks of recovery, peripheral nerve stimulation was reinitiated and the participant became pain-free through the 9-mo follow-up. At 12 mos, Brief Pain Inventory-Short Form Question 3 score was 1. This case report demonstrates the feasibility of a single-lead, fully implantable peripheral nerve stimulation system for refractory hemiplegic shoulder pain.

Percutaneous peripheral nerve stimulation for chronic pain in subacromial impingement syndrome: a case series.

OBJECTIVE: The objective of this study was to determine the effect of peripheral nerve stimulation (PNS) on pain reduction for those with refractory subacromial impingement syndrome (SIS) and to evaluate the association with reduced disability, impairment, and safety. Our hypotheses are that PNS will be associated with a reduction in pain, impairment and disability, and improvement in quality of life while demonstrating safety. MATERIAL AND METHODS: Adults with shoulder pain of at least six months duration were recruited for a three-week treatment of percutaneous PNS applied through a percutaneous electrode to the axillary motor points of the deltoid muscle. Subjects were followed for 12 weeks after treatment. The primary outcome was the worst pain in the last week, and secondary outcomes included pain interference, the Disabilities of the Arm, Shoulder, and Hand questionnaire, shoulder abduction range of motion, and safety. Analysis was with a linear mixed model. RESULTS: Ten subjects were recruited. Longitudinal analysis demonstrated significant reduction in pain relative to baseline (F(1, 66) = 12.9, p < 0.01). After correcting for multiple comparisons, there were significant reductions at explantation and all follow-up time points when compared with baseline. There were also significant improvements in pain interference (F(1,65) = 15.0, p < 0.01), the Disabilities of the Arm, Shoulder, and Hand questionnaire (F(1,35) = 7.0, p = 0.01), and shoulder abduction range of motion (F(1,35) = 6.3, p = 0.02). CONCLUSION: Intramuscular PNS for chronic shoulder pain due to SIS is a safe treatment associated with pain reduction, lower pain interference with activities of daily living, reduced disability, and improved shoulder abduction. Pain reduction is maintained for at least 12 weeks after treatment.

Peripheral nerve stimulation compared with usual care for pain relief of hemiplegic shoulder pain: a randomized controlled trial.

OBJECTIVE: This study sought to establish the efficacy of single-lead, 3-wk peripheral nerve stimulation (PNS) therapy for pain reduction in stroke survivors with chronic hemiplegic shoulder pain. DESIGN: This study is a single-site, pilot, randomized controlled trial of adults with chronic shoulder pain after stroke. Participants were randomized to receive a 3-wk treatment of single-lead PNS or usual care. The primary outcome was the worst pain in the last week (Brief Pain Inventory, Short Form, question 3) measured at baseline and weeks 1, 4, 12, and 16. The secondary outcomes included pain interference (Brief Pain Inventory, Short Form, question 9), pain measured by the ShoulderQ Visual Graphic Rating Scales, and health-related quality-of-life (Short-Form 36 version 2). RESULTS: Twenty-five participants were recruited, 13 to PNS and 12 to usual care. There was a significantly greater reduction in pain for the PNS group compared with the controls, with significant differences at 6 and 12 wks after treatment. Both PNS and usual care were associated with significant improvements in pain interference and physical health-related quality-of-life. CONCLUSIONS: Short-term PNS is a safe and efficacious treatment of shoulder pain. Pain reduction is greater compared with usual care and is maintained for at least 12 wks after treatment.

Single-lead percutaneous peripheral nerve stimulation for the treatment of hemiplegic shoulder pain: a case series.

OBJECTIVE: Previous studies demonstrated the efficacy of Intramuscular Nerve (IMN) therapy with a 4-lead percutaneous, peripheral nerve stimulation (PNS) system in reducing hemiplegic shoulder pain (HSP). This case series investigates the feasibility of a less complex, single-lead approach in reducing HSP. METHODS: Eight participants received one percutaneous intramuscular lead in the hemiparetic deltoid muscle and were then treated 6 hours/day for 3 weeks. The primary outcome measure was the Brief Pain Inventory (Short-Form) Question 3 (BPI3), which queries worst pain in the last week on a 0 to 10 numeric rating scale. Secondary outcomes included pain interference (BPI9) and Medical Outcomes Study Short-Form 36 (SF-36v2). Primary and secondary outcomes were assessed at the end of treatment (EOT) and 1 and 4 weeks after the EOT. RESULTS: All participants tolerated the treatment well with 96% compliance. All leads remained infection-free and were removed intact at the EOT. On average, participants exhibited 70% reduction in BPI3 at the EOT and 61% reduction at 4 weeks after the EOT. All participants satisfied the success criterion of at least a 2-point reduction in BPI3 at the EOT. Longitudinal analysis revealed significant treatment effect for BPI3 (F = 14.0, P < 0.001), BPI9 (F = 5.9, P < 0.01), and the bodily pain domain of SF-36v2 (F = 12.8, P < 0.001). CONCLUSION: This case series demonstrates the feasibility of a single-lead, 3-week IMN therapy for the treatment of chronic HSP. Additional studies are needed to further demonstrate safety, efficacy, and long-term benefit, define optimal prescriptive parameters and dose, and expand clinical indications.

Single-lead percutaneous peripheral nerve stimulation for the treatment of shoulder pain from subacromial impingement syndrome.

This case report demonstrates the feasibility of a single-lead peripheral nerve stimulation system for the treatment of pain secondary to chronic subacromial impingement syndrome. The participant was a 57-year-old man who experienced persistent pain from subacromial impingement syndrome for 20 months despite having undergone conservative therapy of steroid injection and physical therapy. After study enrollment, a single intramuscular lead was placed percutaneously into the deltoid muscle of the affected shoulder. He was treated 6 hours per day for 3 weeks and the lead was removed. The primary outcome measure was the Brief Pain Inventory (Short-form) Question 3 (BPI 3), which queries the worst pain in the last week on a 0-10 numerical rating scale. At baseline, BPI 3 was an 8. At the end of treatment and at 4 and 12 weeks after treatment, BPI 3 scores were 2, 0, and 0, respectively. Substantial improvements in shoulder impairment, quality of life, and shoulder disability measures were also observed. Additional studies are needed to further demonstrate safety and efficacy, determine optimal dose, define optimal prescriptive parameters, expand clinical indications, and demonstrate long-term effect.

Electrical stimulation of the urethra evokes bladder contractions and emptying in spinal cord injury men: case studies.

OBJECTIVE: Electrical stimulation of the urethra can evoke bladder contractions in persons with spinal cord injury (SCI). The objective of this study was to determine whether electrical stimulation of the urethra could evoke bladder contractions that empty the bladder. METHODS: The first patient was a 45-year-old man with a T6 ASIA A SCI secondary to a gunshot wound 15 years prior. The second patient was a 51-year-old man with a T2 ASIA A SCI secondary to a fall from scaffolding 2 years prior. Both patients demonstrated neurogenic detrusor overactivity on urodynamics and managed their bladder with clean intermittent catheterization and oxybutynin medication. Following informed consent, each patient discontinued oxybutynin 2 days prior to urodynamic testing. Urodynamics were performed with a custom 12 French balloon catheter mounted with ring-shaped electrodes (3 mm) positioned in the prostatic urethra. After filling the bladder to approximately three-fourth of capacity at a rate of 25 ml/minute, the urethra was stimulated with a range of parameters to determine whether electrical stimulation could evoke a bladder contraction and empty the bladder. RESULTS: Electrical stimulation of the prostatic urethra evoked bladder contractions (peak detrusor pressures of 60-80 cm H(2)O) that emptied the bladder in both subjects. In the first subject, stimulation (9-12 mA, 20 Hz) emptied 64-75%, leaving post-void residual volumes (PVRs) of 41-20 ml. In the second subject, stimulation (20 mA, 20 Hz) emptied 68-77%, leaving PVRs of 56-45 ml. CONCLUSION: Urethral stimulation evoked bladder emptying in persons with SCI.

Single-lead percutaneous peripheral nerve stimulation for the treatment of hemiplegic shoulder pain: a case report.

Previous studies demonstrated the efficacy of 6 weeks of a 4-lead percutaneous, peripheral nerve stimulation system in reducing hemiplegic shoulder pain. This case report describes the first stroke survivor treated for 3 weeks with a less complex, single-lead approach. The participant was a 59-year-old male who developed hemiplegic shoulder pain shortly after his stroke 7.5 years prior to study enrollment and was treated with multiple modalities without sustained pain relief. After study enrollment, a single intramuscular lead was placed percutaneously into the deltoid muscle. He was treated 6 hours per day for 3 weeks and the lead was removed. The primary outcome measure was the Brief Pain Inventory (Short-Form) Question 3 (BPI-3), which queries the worst pain in the last week on a 0 to 10 numeric rating scale. At baseline, BPI 3 was an 8. At the end of treatment and at 1 and 4 weeks after treatment was completed, BPI 3 scores were 3, 2, and 2, respectively. Substantial improvements in quality of life measures were also observed. The participant remained infection-free and the lead was removed fully intact. After completing the study protocol, the participant was followed clinically for 13 months posttreatment with complete resolution of hemiplegic shoulder pain. This case report demonstrates the feasibility of a single-lead peripheral nerve stimulation for the treatment of chronic hemiplegic shoulder pain. Additional studies are needed to further demonstrate safety and efficacy, determine optimal dose, define optimal prescriptive parameters, expand clinical indications, and demonstrate long-term effect.

Electrical stimulation of the urethra evokes bladder contractions in a woman with spinal cord injury.

OBJECTIVE: Electrical stimulation of pudendal urethral afferents generates coordinated micturition in animals and bladder contractions in men after spinal cord injury (SCI), but there is no evidence of an analogous excitatory urethra-spinal-bladder reflex in women. The objective of this study was to determine whether electrical stimulation of the urethra could evoke bladder contractions in a woman with SCI. CASE REPORT: A 38-year-old woman with a C6 ASIA A SCI who managed her bladder with clean intermittent catheterization and oxybutynin demonstrated neurogenic detrusor overactivity on urodynamics. Oxybutynin was discontinued 2 days prior to urodynamic testing with a custom 12F balloon catheter mounted with ring-shaped electrodes located in the bladder neck, mid urethra, and distal urethra. The inflated balloon was placed against the bladder neck to stabilize the catheter electrodes in place along the urethra. However, the balloon limited emptying during contractions. Urodynamics were performed at a filling rate of 25 mL/minute until a distention-evoked bladder contraction was observed. The urethra was stimulated over a range of bladder volumes and stimulus parameters to determine whether electrical stimulation could evoke a bladder contraction. FINDINGS: Electrical stimulation via urethral electrodes evoked bladder contractions that were dependent on bladder volume (>70% capacity) and the intensity of stimulation. CONCLUSIONS: This is the first report of an excitatory urethra-spinal-bladder reflex in a woman with SCI. Future studies will determine whether this reflex can produce bladder emptying.