Clinical Scorecard: Initial Results from a Flexible ECAP-Based Closed Loop Utilizing Multiplexed Spinal Cord Stimulation Waveforms: A Single-Arm Study with In-Clinic Randomized Crossover Evaluation

At a Glance

Key Highlights

• CL-SCS system reduces overstimulation compared to open-loop (OL) fixed amplitude SCS, improving patient comfort.
• 60% of subjects preferred below-perception waveforms during at-home use, indicating tolerability of imperceptible stimulation.
• At 3 months, 86% of subjects with low-back/leg pain and all with upper limb pain reported ≥50% pain reduction relative to baseline.

Guideline-Based Recommendations

Diagnosis

• Identify chronic neuropathic pain refractory to conservative treatments as indication for SCS.

Management

• Use ECAP-based closed-loop SCS systems to provide consistent dosing by automatically adjusting stimulation amplitude in response to neural signals.
• Program stimulation amplitude to patient comfort and allow delivery of various waveforms including multiplexed and high-frequency waveforms.
• Consider closed-loop systems to reduce patient burden of manual adjustments and improve therapy consistency.

Monitoring & Follow-up

• Evaluate patient-reported overstimulation and pain relief regularly, including in-clinic randomized crossover testing when feasible.
• Monitor for changes in lead-to-cord distance and stimulation dose consistency during different postures and activities.

Risks

• Overstimulation may cause discomfort or side effects such as muscle cramping, nausea, tinnitus, or headaches, especially with high-frequency waveforms.
• Under-dosing due to patient adjustments or fixed amplitude settings may lead to inadequate pain relief and therapy discontinuation.

Patient & Prescribing Data

Sixty subjects implanted with the ECAP-based CL-SCS system, 54 completed 3-month follow-up

Majority preferred below-perception stimulation waveforms; closed-loop adjustment significantly reduced overstimulation and improved pain outcomes at 1 and 3 months

Clinical Best Practices

• Implement ECAP-based closed-loop SCS to maintain consistent stimulation dose despite postural changes.
• Program stimulation amplitude tailored to patient comfort, including imperceptible levels when preferred.
• Use multiplexed and high-frequency waveforms to optimize analgesia while minimizing side effects.
• Educate patients on the benefits of closed-loop systems to reduce manual adjustments and improve therapy adherence.
• Regularly assess pain relief and overstimulation to guide therapy optimization.

References

• ClinicalTrials.gov NCT05177354