Spinal Cord Injury Community Personal Opinions and Perspectives on Spinal Cord Stimulation

Neuromodulation is a technology that can alter nerve activity through stimulation by different types of methods (i.e., electrical or pharmaceutical) and to various areas of the body (i.e., brain, spinal cord, peripheral nerves).¹  Spinal cord stimulation (SCS) is a specific type of neuromodulation that uses energy as a stimulus (e.g., electrical or magnetic) to act on the area of the spinal cord.²  SCS can involve the surgical placement of electrodes on the spinal cord through epidural SCS (ESCS) or on the skin on top of the spine through transcutaneous SCS (TCSCS).³ 

For over 50 years, ESCS has been used to treat pain when conventional treatment methods fail.^4,5  Interest in ESCS for the functional improvement of people living with spinal cord injury (SCI) has grown since 2011 when the first application of ESCS in a person with SCI showing standing and some voluntary control of lower extremities was published.⁶  There have been several publications over the past 10 years exploring the effects of both ESCS and TCSCS on motor and autonomic outcomes.^7–26  Currently, the development of SCS as a neuro-restorative therapy is being evaluated in people living with SCI in clinical trials to determine the efficacy and safety for motor, sensory, and autonomic recovery.²³ 

Within the academic and research settings, it is important to engage people with lived experience, including persons with SCI and their caregivers and family, as part of the research process.^23,27  Researchers partnering with knowledge users will increase the relevance, applicability, and impact of research results, including social value.^27,28  In 2004, Anderson²⁹  revealed that outcomes studied by researchers did not match those prioritized by the SCI community, and subsequently there has been a push to align research priorities with the priorities of those with lived experience of SCI.^29–34 

To date, the perspectives of people living with SCI who are seeking SCS for functional recovery are not well known. As such, there is an opportunity to incorporate the lived experience of SCI into the planning and delivery of this promising treatment. The goal of this study was to engage people living with SCI and obtain input on their top priorities for recovery, expected meaningful benefits and risk tolerance, clinical trial design, and overall interest in this technology.

The survey content was developed by an advisory team, comprised of four members of the North American Spinal Cord Injury Consortium (NASCIC) and five employees of the Praxis Spinal Cord Institute. The team included six people with lived experience of SCI who had diverse experience in advocacy work, participation in clinical trials, and research and a strong connection to their local communities across Canada and the United States. Seven virtual meetings were organized with each member contributing to, reviewing, and approving documents. The survey topics, target audience, questions, response options, title, glossary, and promotional materials were co-developed among the team. Decisions were made using a consensus approach. See the supplementary material for a copy of the survey (eAppendix A).

An independent research firm was contracted to program the survey, host the website where the survey could be accessed, and collect the data. The final draft survey was tested by 12 people (including advisory team members and additional staff members) for survey logic, clarity of text and instructions, and any programming issues. Participants accessed the survey using links distributed through social media platforms, flyers, and newsletters that were shared by SCI organizations. The approved survey could be accessed through the internet, and data collection occurred from February 2020 to May 2020. Unique site visitors were not tracked; no IP addresses, cookies, or log file analysis were used.

The survey was programmed to have one question per page with error logic and adaptive questioning embedded. Missing or improperly entered responses were flagged, and responses could be reviewed or changed with a back button. Each question had preset responses and/or open text fields. Questions and responses in the survey were not randomized, and they appeared in the same sequence for every participant. Some of the questions were skipped for individuals who reported having had prior personal experience with SCS. At the beginning of the survey, there was a short introduction about SCS, its current use as a therapy, challenges in the field, the purpose of the survey, an approximate time required to complete the survey, and the expected number of participants. Additionally, there was a page that described the team who developed the survey content. All participants provided informed consent, and participation in the survey was voluntary. No monetary incentives were given to participants, and only anonymous data were collected (i.e., no names, dates of birth, or contact information were collected).

The research study and all related research survey materials, including the survey design, advertisement/promotional items, and consent statement, were approved by an accredited independent review board (Veritas Independent Review Board).

Completed surveys were analyzed. The Monte-Carlo estimation of a Fisher exact test was used to determine where there were differences based on the injury severity and level groups (complete tetraplegia, incomplete tetraplegia, complete paraplegia, incomplete paraplegia) by sex (male, female, another sex, prefer not to answer), gender (male, female, nonbinary, another gender, prefer not to answer), age (18–29, 30–44, 45–59, 60–74, 75+), time post injury (<1 year, 1–5 years, 6–10 years, >10 years), and country (United States, Canada, other). If there was evidence to suggest a significant difference, post hoc analysis was used to test which responses were significantly different. No statistical corrections such as weighting of items or propensity scores were used.

In total, there were 231 respondents who completed the survey; 223 identified themselves as a person living with an SCI, and 8 reported being a caregiver. Given the low number of caregivers, the results include only participants living with an SCI. The majority of respondents were male at birth (64%), identified as male (64%), and were more than 10 years post SCI (63%). Mean age of respondents was 50.8 ± 13.7 years, and the majority of respondents lived in the United States (69%). Most individuals sustained a traumatic SCI (81%), 45% classified themselves as having tetraplegia, and 49% of all the respondents reported having a cervical-level injury. Additional demographic and injury characteristics are summarized in Table 1. Most people reported that they get their information on SCS through internet searches (159/223, 71%), followed by news media stories (104/223, 47%), published research (79/223, 35%), peers with SCI (67/223, 30%), health care providers (65/223, 29%), or speaking with someone who has had experiences with SCS therapy (41/223, 18%). Respondents also added social media posts, podcasts, SCI-related organizations, specific magazines, and training centers as additional sources of information for SCS.

The majority (94%) of respondents had not previously experienced SCS (209/223), which included 10% (23/223) who applied or were accepted and waiting to be part of a clinical trial. Approximately 38% (79/207) of respondents reported they had previously asked a health care professional about SCS. Of those who asked, only 29% (23/79) felt that they were provided with useful information.

Individuals without personal experience of SCS (n = 209) were asked to choose their five overall priorities for improved outcomes as a result of SCS (Figure 1). These priorities differed by the level and severity of injury (complete tetraplegia, incomplete tetraplegia, complete paraplegia, incomplete paraplegia, except for bowel and bladder function which was common for all groups (eAppendix B). Persons with complete and incomplete tetraplegia ranked fine motor skill (hands/fingers) and upper body function (shoulders, arms, hands) in their top five priorities, whereas individuals with complete and incomplete paraplegia ranked standing and walking highly.

Respondents were then asked to rank the five priorities that they selected. Based on the level and severity of injury, the priority that was ranked first for the persons with complete and incomplete tetraplegia was fine motor skills (39%, n = 14; 22%, n = 13, respectively). For complete paraplegia, it was bowel function (30%, n = 13); and for incomplete paraplegia, it was standing and walking (46%, n = 28) (Figure 2).

Meaningful benefits from SCS therapy were graded by respondents who did not have previous experience with SCS (n = 209) using a 5-point scale (with 5 meaning it is extremely important and 1 meaning it is not at all important). The top five priorities for meaningful benefits from SCS therapy were (1) performing bowel and bladder care, (2) less reliance on caregivers, (3) maintaining physical health, (4) ability to transfer, and (5) mobility outside of the home (Figure 3).

The risks respondents were most concerned about were (1) further loss of function, (2) increased neuropathic pain, (3) requiring additional surgery from complications, (4) skin breakdown over the implant, and (5) infection requiring antibiotics (Figure 4).

In terms of the treatment preferences, 91% (203/223) of respondents are willing to follow a specific training/rehabilitation protocol. When asked about the location of the training, 48% (107/223) of respondents stated they would want to train at a rehabilitation-type facility, 34% (76/223) at home, and 6% (13/223) in a gym. When asked with whom they would like to train, 71% (158/223) reported with a physical therapist. With respect to frequency, 27% (60/223) responded to three times per week, 25% (55/203) responded five days a week, and 16% (36/223) responded to every day of the week. For length of each session, 39% (86/223) responded that they preferred 2 hours, 24% (53/223) responded 1 hour, and 14% (31/223) responded 3 hours. When given a choice of how long they would be willing to try the therapy, 23% (52/223) responded 3 to 6 months, and 22% (50/223) chose 2 years or longer. When asked how soon after initial SCS treatment would they be disappointed or regretful if they did not see any improvement, 27% (56/209) responded 3 to 6 months. Almost half, 49% (109/223) of respondents stated that they would be willing to relocate to receive the SCS treatment.

The most common perceived barriers to participation in SCS clinical trials for those who had no prior experience with SCS (n = 209) were the inability to relocate (52%; 116/209), out-of-pocket expenses (51%; 114/209), distance to a study center (39%; 86/209), awareness of therapy (27%; 61/209), and personal support services (22%; 48/209) (eAppendix B).

There was interest in trying TCSCS from 80% (167/209) of respondents, with injury level and severity not showing an effect on the response. For ESCS, the interest was lower at 61% (127/209); similar to TCSCS, there was no effect of injury level and severity on the interest of respondents for this type of therapy.

The goal of this study was to survey individuals living with an SCI to obtain their input and preferences on SCS to inform future clinical research in this area. Results from this study indicate there is a strong interest from the SCI community to be part of TCSCS clinical trials (80% interested) and/or ESCS trials (61%). The majority of respondents (94%) had not experienced SCS, but 10% of this group had applied to be part of a study. As expected, priorities for recovery were different based on the level and severity of injury, whereby respondents with incomplete and complete tetraplegia ranked upper extremity function (hands, fingers, shoulders) as a priority and respondents with incomplete and complete paraplegia ranked standing and walking as a priority. All groups considered bowel and bladder to be important.

In terms of priorities for SCS clinical trials, results from this study align with other studies. In 2004, Anderson²⁹  reported on a survey of 681 individuals with SCI. In both of these surveys, persons with tetraplegia identified arm and hand function as the top priority. Persons with paraplegia in the Anderson survey reported sexual function as the highest priority; whereas in our survey, persons with incomplete paraplegia ranked standing/walking as the top priority, and for complete paraplegia, it was bowel function. These differences for persons with paraplegia may be due to differences in sample characteristics considering that in our survey more participants were female (35% in this study vs. 25% in Anderson).²⁹  There may have also been differences in the age at injury and time since injury between the studies that could not be easily compared and would potentially affect the ranking of sexual function.

The importance of bowel and bladder function was identified as a priority in both the survey by Anderson²⁹  and in our study. A recent scoping review by Laskin et al.²³  of SCS studies published between 1985 and 2021 identified that motor recovery and ambulation were the most frequently reported primary outcomes for TCSCS and ESCS studies. To ensure there is alignment between the priorities of persons living with SCI and clinical research, an integrated knowledge translation approach, where persons with lived experience are meaningfully engaged in all phases of research, is critical.³⁵  This will help ensure appropriate selection of the primary outcome in clinical trials and the associated measurements. Furthermore, consensus on the minimum set of self-reported measures for bowel and bladder function recommended by Tate et al.³⁶  will facilitate the inclusion of the person’s perspective in future studies.

Input from respondents regarding clinical trial design could not only inform SCS clinical trials but could also be applied to other SCI research. The results from this study have shown that people with SCI want access to innovative treatments, and barriers are related to the inability to relocate, distance to study center of studies, and out-of-pocket expenses. In designing clinical studies, it is important to consider the inclusion of multiple sites so that more participants can access the innovative treatments and provision of financial support for travel, relocation, and caregiving. There is an opportunity to improve the awareness about SCS, not only for individuals with SCS but also for their health care providers given that only 30% of those who asked for information about SCS from their health care provider felt that the information provided was useful. The majority of the respondents (71%) get their information on SCS through internet searches; this information could be leveraged to increase awareness of new and ongoing clinical trials, as well as for results and updates.

Looking beyond clinical trials, implementation of SCS into clinical practice will require the support of additional stakeholders, such as physicians and physical therapists. The results of a survey published in 2019 aimed to identify potential barriers toward implementation of epidural stimulation for functional improvement after SCI.³⁷  The study also shows the increasing knowledge about and the demand for SCS with 62% of the physicians surveyed having been asked by people with SCI about epidural stimulation. Several physician-perceived barriers were identified, including need for additional efficacy studies, lack of clear guidelines on stimulation parameters, and the inability to determine who will benefit from the therapy. Addressing the barriers identified from this work will help to close the gaps in knowledge and improve clinical implementation of SCS as a therapy.

This study is an example of a successful partnership between researchers at Praxis Spinal Cord Institute and the North American SCI Consortium representing individuals with lived experience. In designing this study, we used an integrated knowledge translation approach, whereby persons living with SCI were engaged in all stages to cocreate the knowledge and disseminate the results.³⁵  Key lessons learned included using video conferencing to ensure there was an opportunity for all the participants to join, starting with general topics/goals of the study but allowing for brainstorming sessions and flexibility, ensuring there was adequate time so all the team members were heard, having open communication and being available by email, having funding to compensate all team members for their time, and being flexible in how it is distributed. There were numerous benefits from using an integrated knowledge translation approach that included obtaining input on relevant questions and responses (including suggesting examples), identifying where additional explanatory text or glossary items were needed, reviewing the questions during pilot testing, promoting the survey, and analyzing the results (looking at the survey results and deciding what to present and how best to present the data).

In considering these results, it is important to acknowledge the limitations. This study utilized an online survey, so the respondents and their responses may not be representative of all individuals who have an interest in SCS and may not accurately reflect the entire population of people who are living with SCI. Because this was an open survey promoted by two nonprofit organizations within the SCI community, individuals who already had an interest in SCS may have been more likely to complete this survey. This may be reflected by the responses for the questions relating to participation in SCS clinical trials given that 6% of survey respondents had prior personal experience with SCS and 10% had previously applied or been accepted to be part of an SCS clinical trial.

Results from this survey may assist researchers to improve the design of clinical trials for SCS by reflecting the priorities for functional improvement and treatment preferences. Participant recruitment can be improved by addressing concerns identified through the survey, including the need for increased awareness of SCS and clinical trials, improving the ease of participation, and acknowledging the perceived potential risks. As this technology continues to demonstrate positive safety and efficacy in clinical trials, results from this survey may benefit clinical, regulatory, and reimbursement decision-making bodies with the translation of this technology. Considering the preferences of people with lived experience of SCI in these decisions is vital to ensuring that emerging technologies are feasible, relevant, applicable, and impactful to the SCI community.

We would like to thank everyone who took the time to complete the survey. Special thanks to the North American Spinal Cord Injury Consortium (NASCIC) for their collaboration, partnership, and promotion of the survey among their membership. This work was made possible through the NASCIC Project Partnership Program, and their support was invaluable in setting up the committee and providing guidance throughout the process. We would like to acknowledge Dr. Peter Grahn for his review of the survey and Tian Shen and Abigail Abdulgapul for their help with data analysis. We also thank Phil Giborski and the team at Mustel Group for their assistance with formatting the survey, hosting the survey website, and providing technical support.