A Proposed Psychologic Clearance Algorithm for Spinal Cord Stimulation Implantation: Mini Review

Terrance C. Jenkins^1*, Kristy Fisher²

¹Department of Psychiatry and Behavioral Sciences, Morehouse School of Medicine, Atlanta GA, USA

²Spine and Orthopedic Center, Deerfield Beach FL, USA

Introduction

Spinal Cord Stimulation (SCS) for the management of chronic pain conditions that do not adequately respond to conventional treatments is an established therapeutic intervention. This therapy provides long-term neuromodulation therapy for a number of clinical indications and continues to become more prevalent. Technological advancements continue to increase long-term success by improving the efficacy, utility, and precision of SCS; however, patient selection remains a key determinant of long-term therapeutic success¹. Various psychological factors including mental health treatment status, psychosocial factors, and pain perception have been demonstrated to significantly influence patient outcomes following SCS implantation^2,3,4,5,6,7. Traditional screening methods typically result in patients with certain psychological factors being excluded as surgical candidates, and do not offer a path to obtain clearance or improve outcomes. Though there is growing recognition of the importance of these factors as barriers to success, there continues to be a lack of standardized protocols guiding psychological assessment prior to SCS implantation.

A Proposed Psychologic Clearance Algorithm for Spinal Cord Stimulation Implantation Supported by a Scoping Review, attempts to address this by proposing a structured framework for pre-op psychological evaluation⁸. The authors conduct a scoping review of existing literature to identify key psychological elements influencing SCS success and failure. Their findings spawned the development of a psychological clearance algorithm that is aimed at standardizing the screening process prior to implantation. The algorithm proposed by the authors incorporates multiple evidence-based assessments in addition to clinical judgment to guide physicians in identifying patients at high-risk of treatment failure⁸. It details a stepwise algorithm for implementing interventions prior to moving forward with SCS implantation.

This mini review examines the proposed algorithm, evaluating its strengths and limitations, draws comparisons to existing methods, and discusses potential implications for clinical practice. By analyzing the methodology of the scoping review and the practicality of the proposed algorithm, this mini review aims to highlight the significance of psychological assessment in optimizing SCS outcomes in all patients.

Methodology

The authors of this Mini review analyzed and reviewed the initial proposed algorithm based on the scoping review. The scoping review utilized an established framework, aimed at synthesizing existing literature on the psychological factors that predict SCS failure or success. They reviewed current literature published between 2000 and 2022 to systematically analyze studies that evaluate exclusion criteria, psychological factors influencing SCS outcomes, as well as the validity of screening tools and stragities for intervention. The search strategy utilized a number of databases, focusing on reviewing case reports, case studies, clinical trials and other peer-reviewed studies. Only English language studies of patients aged 18 or older were evaluated, with a total of 62 studies meeting their criteria. After analyzing the studies, the authors were able to synthesize what they propose as a standardized psychological clearance algorithm for SCS implantation. (Figure 1)

Figure 1: Methodology. Describes process in which manuscripts were selected for use in scoping review. Provides exclusionary criteria and identifies the distribution of publication types used to support the study.

Discussion

The proposed algorithm

The goal of this proposed algorithm is to standardize the psychological assessments performed prior to undergoing SCS implantation⁸. It also allows pain physicians without a psychiatric background to have a deeper understanding of psychological clearance factors. The scoping review highlights how factors such as depression, anxiety, pain catastrophizing, and poor coping ability, can significantly impact success of SCS. Additionally, conditions that were previously viewed as contraindications such as active psychosis, suicidality, and substance use, are all represented in the algorithm. The inclusion of a large variety of psychiatric disorders provides clinicians with more screening options, potentially increasing access for previously excluded patients. The review remains the latest of its kind and includes all other relevant past publications, offering pain physicians the most up to date guidance for psychological clearance.

Standardization of the psychological screening process provides a structured and repeatable framework for clinicians to evaluate candidates. The algorithm’s use of evidence based psychological screening tools ensures consistency across different clinical settings and potentially captures more symptoms that lead to poor SCS outcomes. Unlike other preoperative screening tools found in the literature, this algorithm does not exclusively focus on exclusionary factors, but offers targeted interventions aimed at improving patient outcomes prior to intervention^9,10. The framework focuses on increasing the likelihood of treatment success rather than absolute exclusion of patients with concerning psychological factors. It incorporates a multidisciplinary approach to pain management, encouraging collaboration between pain physicians, psychologists, and psychiatrists to ensure a more holistic and comprehensive patient evaluation.

Potential limitations and areas of improvement

The algorithm is primarily based on a review of current literature, and thus far lacks the clinical validation of its real-world effectiveness. However, with increased routine implementation in pain practices, the algorithm could reshape our approach to psychological clearance. It incorporates multiple screening tools that rely heavily on psychologists being trained in their administration. Even with adequate training, the subjective nature of some assessments could potentially introduce variability in assessment outcomes, that can influence clinical decision making. The subjective nature of these assessments also includes cultural biases. Some of the algorithm pathways recommend multiple steps of time-consuming evaluations, with each item leading to another screening tool. The increased time required for clearance may cause significant delays in patients receiving pain relief. Further standardizing and limiting the use of more subjective screening assessments may reduce the amount of time required for evaluation and well as the risk of variability. While acknowledging the potential for increased time demands, it is important to consider that the algorithm offers a new opportunity for therapeutic intervention for individuals who are traditionally ineligible. The multistep algorithm incorporates only the most evidence-based clinician administered assessments but requires a good understanding of each condition or trait. This may prompt some pain physicians to limit its use to psychiatrically or psychologically trained professionals and the need for further assessment. However, this algorithm successfully illustrates the thought pattern that should be exhibited by psychologists in the clearance process. By developing an understanding of the reasoning underlying the clearance process, pain physicians without a psychiatric background can be more equipped to better identify more patients who could potentially be excellent candidates for SCS.

Clinical implications and future directions

The findings of the scoping review emphasize the importance of the psychological clearance of SCS candidates. Currently, such clearance follows no standardized protocol, allowing for a wide degree of variability. Using consistent tools and methods to guide clinical decision making can improve candidate selection as well as rates of long term SCS success. Management of these psychiatric conditions via lifestyle modifications, pharmacotherapy, and psychotherapy may be beneficial in reducing the failure rate of SCS and improving outcomes^1,11.

The review highlights various psychological factors that predict SCS treatment outcomes and goes beyond identification of exclusionary factors, incorporating recommendations for interventions. This highlights the need for an evidence-based uniform approach to psychological clearance. A standardized clearance process can increase the effectiveness of the screening process and increase access to SCS treatment in patients that may have been previously excluded. It may allow for the early recognition and treatment of various psychological conditions and thus improve the rate of SCS success. Clinical validation studies will be essential to critically assess the real-world utility of this algorithm. A future multi-site, non-inferiority trial comparing the proposed algorithm to management as usual could provide such empirical validation. The multidisciplinary approach to clearance encouraged by the algorithm, further highlights the link between mental wellbeing and pain^12,13. Having a systematic protocol may also provide objective evaluations rather than subjective assessments alone. Multidisciplinary care of patients may serve to optimize treatment planning and help adjust trajectories to ensure optimal patient response. Formalized protocols for psychological clearance of SCS candidates would help ensure an evidence-based approach to improving SCS outcomes.

Conclusion

The proposed psychological clearance algorithm takes a step towards standardizing clearance assessments. The scoping review highlights prevalent psychological factors that can influence SCS treatment outcomes. The algorithm goes beyond simply providing steps for patient exclusion by utilizing validated screening tools to identify concerning symptoms and offers recommendations for evidence-based interventions prior to moving forward with SCS. It provides a standardized framework that future clinical research can build upon to not only validate the algorithm but make it a more robust tool for the collective pain management team. The scoping review highlights the importance of having a multidisciplinary and collaborative approach to pain management in order to improve patient treatment outcomes. Validation and continued evolution of this algorithm can guide clinicians in moving towards a more comprehensive and personalized approach to psychological clearance. This ultimately increases access to more patients by optimizing their potential for SCS candidacy and success.

Conflict of Interest

The authors have no conflicts of interest to disclose regarding this manuscript.

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