Patient Experience with Open-Loop Spinal Cord Stimulation Devices Across Manufacturers and Waveforms: Results of a...

Spinal cord stimulation (SCS) is an established, efficacious therapy for chronic neuropathic pain. SCS therapy has the unique challenge of variability in the amount of applied stimulation that reaches the cord as it moves within the spinal canal during the patient's activities of daily living (ADLs). This variability is experienced by the patient as transient instances of overly strong (i.e., overstimulation) or overly weak (i.e., understimulation) therapy when the person changes their posture. While patients report a high degree of satisfaction with the pain reduction and quality-of-life improvement from this therapy, they make manual adjustments to the programmed settings, including turning the amplitude up, down or off, to avoid these events.

This study was undertaken to understand patients' experiences with the current generation of open-loop (OL) SCS devices and what innovations would be meaningful to those patients.

The study was a prospective, double-blind survey of a representative sample of SCS patients.

The study was executed by a third-party vendor as a 20-minute electronic survey.

Patients were recruited from the database of another market research vendor and screened via email or phone. Eligibility was determined based on screening questions, including location of implant, manufacturer, time since implant, and location of pain. Consent was obtained prior to participation, and patients were compensated for their time. The questions were tested prior to being administered to the patients in a separate cohort for ease of understanding and adequacy of choices.

One hundred patients representative of the SCS population provided responses to this survey; the patients were implanted with devices manufactured by Medtronic (33%), Nevro (28%), Boston Scientific (24%), and Abbott (15%). Over 80% of patients were being treated for low-back pain with or without leg pain. Regardless of whether the patient was programmed to receive sub- or supra-perception therapy, 58% reported experiencing overstimulation, and 46% reported understimulation as they engaged in ADLs. Most of the patients (85%) reported avoiding one or more ADLs, and 70% reported increasing or decreasing the level of therapy proactively to avoid those side effects, resulting in a significant burden of device management. Over 80% of patients expressed being satisfied or very satisfied with the pain relief provided by the devices and technology.

This study has the inherent limitations of a direct-to-patient survey design, including subjective interpretation of the questions without a complete understanding of the relative merits of different waveforms or devices (e.g., MRI conditionality).

Patients report a high degree of satisfaction with SCS therapy for chronic pain regardless of the years since their implants. The data from this survey suggest opportunities for further innovation, especially attempts to minimize the side effects of therapy, reduce the burden of device management, and offer a more automatic and seamless experience. Novel closed-loop SCS systems have been demonstrated to be effective in reducing therapy side effects and ensuring consistent dosing as patients engage in ADLs. More evidence from long-term follow-up on patients implanted with closed-loop SCS systems is necessary to understand the overall benefits for SCS patients.