Association of Spinal Cord Stimulator Implantation With Persistent Opioid Use in Patients With Postlaminectomy Syndrome

The Role and Applications of Artificial Intelligence in the Treatment of Chronic Pain

PURPOSE OF REVIEW

This review aims to explore the interface between artificial intelligence (AI) and chronic pain, seeking to identify areas of focus for enhancing current treatments and yielding novel therapies.

RECENT FINDINGS

In the United States, the prevalence of chronic pain is estimated to be upwards of 40%. Its impact extends to increased healthcare costs, reduced economic productivity, and strain on healthcare resources. Addressing this condition is particularly challenging due to its complexity and the significant variability in how patients respond to treatment. Current options often struggle to provide long-term relief, with their benefits rarely outweighing the risks, such as dependency or other side effects. Currently, AI has impacted four key areas of chronic pain treatment and research: (1) predicting outcomes based on clinical information; (2) extracting features from text, specifically clinical notes; (3) modeling 'omic data to identify meaningful patient subgroups with potential for personalized treatments and improved understanding of disease processes; and (4) disentangling complex neuronal signals responsible for pain, which current therapies attempt to modulate. As AI advances, leveraging state-of-the-art architectures will be essential for improving chronic pain treatment. Current efforts aim to extract meaningful representations from complex data, paving the way for personalized medicine. The identification of unique patient subgroups should reveal targets for tailored chronic pain treatments. Moreover, enhancing current treatment approaches is achievable by gaining a more profound understanding of patient physiology and responses. This can be realized by leveraging AI on the increasing volume of data linked to chronic pain.

A sham-controlled, randomized trial of spinal cord stimulation for the treatment of pain in chronic pancreatitis

BACKGROUND

Spinal cord stimulation (SCS) has emerged as a treatment option for patients with chronic pancreatitis (CP) who experience pain that does not respond to standard interventions. However, there is a lack of sham-controlled trials to support its efficacy.

METHODS

This randomized, double-blinded, sham-controlled, cross-over trial enrolled 16 CP patients with insufficient pain relief from standard therapies. Patients underwent high-frequency (1000 Hz) paraesthesia-free SCS or sham for two 10-day stimulation periods, separated by a 3-day washout period. The primary outcome was daily pain intensity registered in a pain diary based on a numeric rating scale (NRS). Secondary outcomes included various questionnaires. Quantitative sensory testing was used to probe the pain system before and after interventions.

RESULTS

The average daily pain score on the NRS at baseline was 5.2 ± 1.9. After SCS, the pain score was 4.2 ± 2.1 compared to 4.3 ± 2.1 in the sham group (mean difference -0.1, 95% CI [-1.4 to 1.1]; P = 0.81). Similarly, no differences were observed between groups for the maximal daily pain score, secondary outcomes or quantitative sensory testing parameters. During an open-label, non-sham-controlled and non-blinded extension of the study, the average daily NRS was 5.2 ± 1.7 at baseline, 3.2 ± 1.8 at 3 months, 2.9 ± 1.9 at 6 months and 3.4 ± 2.2 at 12 months of follow-up (P = 0.001).

CONCLUSION

In this first sham-controlled trial of SCS in painful CP, we did not find evidence of short-term pain relief with paraesthesia-free high-frequency (1000 Hz) stimulation. However, evaluation of the long-term effect by larger sham-controlled trials with long-term follow-up is warranted.

SIGNIFICANCE STATEMENT

In this first sham-controlled trial to apply high-frequency (1000 Hz) spinal cord stimulation in patients with visceral pain due to chronic pancreatitis, we did not find evidence for clinically relevant pain relief. Taken together with potential procedure-related complications, adverse effects and costs associated with spinal cord stimulation, our findings question its use for management of visceral pain.

Patient Out-of-Pocket Costs for Type 2 Diabetes Medications When Aging Into Medicare

Importance

For people with type 2 diabetes (T2D), out-of-pocket medication costs may influence medication choice, adherence, and overall diabetes management and progression. Little is known about how these costs change as insured people enter Medicare at age 65 years, when coinsurance in the coverage gap and catastrophic phases of Part D coverage can be increased greatly by use of insulin and newer, branded medications (eg, dipeptidyl peptidase 4 inhibitors, glucagon-like peptide 1 agonists, and sodium-glucose cotransporter 2 inhibitors).

Objective

To identify whether reaching age 65 years is associated with T2D medication out-of-pocket costs and utilization.

Design, Setting, and Participants

This retrospective cohort study (2012-2020) featuring 7 years of follow-up used prescription drug claims data from the TriNetX Diamond Network. Participants included people in the US with diagnosed T2D, and claims for T2D medications were observed both before and after age 65 years. Data analysis was performed from October 2022 to September 2023.

Exposure

Reaching age 65 years, according to participants' year of birth.

Main Outcomes and Measures

The primary outcome was patient out-of-pocket costs for T2D drugs per quarter (inflation adjusted to 2020 dollars). Utilization, measured as binary utilization of specific classes, and the number of claims for mutually exclusive classes and combinations of classes were also examined. All outcomes were examined using regression discontinuity design.

Results

In claims data for 129 997 individuals with T2D diagnosed at ages 58 to 72 years (mean [SD] age, 65.50 [2.95] years; 801 235 female [50.9%]), reaching age 65 years was associated with an increase of $23.04 (95% CI, $19.86-$26.22) in mean quarterly out-of-pocket costs for T2D drugs, and an increase of $56.36 (95% CI, $51.48-$61.23) at the 95th percentile of spending, after utilization adjustment. Utilization decreased by 5.3% at age 65 years, from 3.40 claims per quarter (95% CI, 3.38-3.42 claims per quarter) to 3.22 claims per quarter (95% CI, 3.21-3.24 claims per quarter), but a shift in composition of utilization, including increased insulin use, was associated with additional increases in patient costs.

Conclusions and Relevance

In this cohort study of individuals with T2D, the increase in spending upon reaching age 65 years (when most people enroll in Medicare) was associated with patient coinsurance in the coverage gap and catastrophic coverage phases of Medicare Part D. The increased patient cost burden at age 65 years and a modest reduction in overall T2D drug utilization suggest that as people with T2D age into Medicare, there is potentially an increase in nonadherence and diabetes complications.

Spinal Cord Stimulator Inequities Within the US Military Health System

OBJECTIVES

Although studies have described inequities in spinal cord stimulation (SCS) receipt, there is a lack of information to inform system-level changes to support health care equity. This study evaluated whether Black patients exhaust more treatment options than do White patients, before receiving SCS.

MATERIALS AND METHODS

This retrospective cohort study included claims data of Black and non-Latinx White patients who were active-duty service members or military retirees who received a persistent spinal pain syndrome (PSPS) diagnosis associated with back surgery within the US Military Health System, January 2017 to January 2020 (N = 8753). A generalized linear model examined predictors of SCS receipt within two years of diagnosis, including the interaction between race and number of pain-treatment types received.

RESULTS

In the generalized linear model, Black patients (10.3% [8.7%, 12.0%]) were less likely to receive SCS than were White patients (13.6% [12.7%, 14.6%]) The interaction term was significant; White patients who received zero to three different types of treatments were more likely to receive SCS than were Black patients who received zero to three treatments, whereas Black and White patients who received >three treatments had similar likelihoods of receiving a SCS.

CONCLUSIONS

In a health care system with intended universal access, White patients diagnosed with PSPS tried fewer treatment types before receiving SCS, whereas the number of treatment types tried was not significantly related to SCS receipt in Black patients. Overall, Black patients received SCS less often than did White patients. Findings indicate the need for structured referral pathways, provider evaluation on equity metrics, and top-down support.

6. Persistent spinal pain syndrome type 2

INTRODUCTION

Persistent Spinal Pain Syndrome (PSPS) refers to chronic axial pain and/or extremity pain. Two subtypes have been defined: PSPS-type 1 is chronic pain without previous spinal surgery and PSPS-type 2 is chronic pain, persisting after spine surgery, and is formerly known as Failed Back Surgery Syndrome (FBSS) or post-laminectomy syndrome. The etiology of PSPS-type 2 can be gleaned using elements from the patient history, physical examination, and additional medical imaging. Origins of persistent pain following spinal surgery may be categorized into an inappropriate procedure (eg a lumbar fusion at an incorrect level or for sacroiliac joint [SIJ] pain); technical failure (eg operation at non-affected levels, retained disk fragment, pseudoarthrosis), biomechanical sequelae of surgery (eg adjacent segment disease or SIJ pain after a fusion to the sacrum, muscle wasting, spinal instability); and complications (eg battered root syndrome, excessive epidural fibrosis, and arachnoiditis), or undetermined.

METHODS

The literature on the diagnosis and treatment of PSPS-type 2 was retrieved and summarized.

RESULTS

There is low-quality evidence for the efficacy of conservative treatments including exercise, rehabilitation, manipulation, and behavioral therapy, and very limited evidence for the pharmacological treatment of PSPS-type 2. Interventional treatments such as pulsed radiofrequency (PRF) of the dorsal root ganglia, epidural adhesiolysis, and spinal endoscopy (epiduroscopy) might be beneficial in patients with PSPS-type 2. Spinal cord stimulation (SCS) has been shown to be an effective treatment for chronic, intractable neuropathic limb pain, and possibly well-selected candidates with axial pain.

CONCLUSIONS

The diagnosis of PSPS-type 2 is based on patient history, clinical examination, and medical imaging. Low-quality evidence exists for conservative interventions. Pulsed radiofrequency, adhesiolysis and SCS have a higher level of evidence with a high safety margin and should be considered as interventional treatment options when conservative treatment fails.

Healthcare Utilization (HCU) Reduction with High-Frequency (10 kHz) Spinal Cord Stimulation (SCS) Therapy

Spinal cord stimulation (SCS) is a well-established treatment for patients with chronic pain. With increasing healthcare costs, it is important to determine the benefits of SCS in healthcare utilization (HCU). This retrospective, single-center observational study involved 160 subjects who underwent implantation of a high-frequency (10 kHz) SCS device. We focused on assessing trends in HCU by measuring opioid consumption in morphine milligram equivalents (MME), as well as monitoring emergency department (ED) and office visits for interventional pain procedures during the 12-month period preceding and following the SCS implant. Our results revealed a statistically significant reduction in HCU in all domains assessed. The mean MME was 51.05 and 26.52 pre- and post-implant, respectively. There was a 24.53 MME overall decrease and a mean of 78.2% statistically significant dose reduction (p < 0.0001). Of these, 91.5% reached a minimally clinically important difference (MCID) in opioid reduction. Similarly, we found a statistically significant (p < 0.01) decrease in ED visits, with a mean of 0.12 pre- and 0.03 post-implant, and a decrease in office visits for interventional pain procedures from a 1.39 pre- to 0.28 post-10 kHz SCS implant, representing a 1.11 statistically significant (p < 0.0001) mean reduction. Our study reports the largest cohort of real-world data published to date analyzing HCU trends with 10 kHz SCS for multiple pain etiologies. Furthermore, this is the first and only study evaluating HCU trends with 10 kHz SCS by assessing opioid use, ED visits, and outpatient visits for interventional pain procedures collectively. Preceding studies have individually investigated these outcomes, consistently yielding positive results comparable to our findings.

Analysis of anemia and iron supplementation among glioblastoma patients reveals sex-biased association between anemia and survival

The association between anemia and outcomes in glioblastoma patients is unclear. We analyzed data from 1346 histologically confirmed adult glioblastoma patients in the TriNetX Research Network. Median hemoglobin and hematocrit levels were quantified for 6 months following diagnosis and used to classify patients as anemic or non-anemic. Associations of anemia and iron supplementation of anemic patients with median overall survival (median-OS) were then studied. Among 1346 glioblastoma patients, 35.9% of male and 40.5% of female patients were classified as anemic using hemoglobin-based WHO guidelines. Among males, anemia was associated with reduced median-OS compared to matched non-anemic males using hemoglobin (HR 1.24; 95% CI 1.00-1.53) or hematocrit-based cutoffs (HR 1.28; 95% CI 1.03-1.59). Among females, anemia was not associated with median-OS using hemoglobin (HR 1.00; 95% CI 0.78-1.27) or hematocrit-based cutoffs (HR: 1.10; 95% CI 0.85-1.41). Iron supplementation of anemic females trended toward increased median-OS (HR 0.61; 95% CI 0.32-1.19) although failing to reach statistical significance whereas no significant association was found in anemic males (HR 0.85; 95% CI 0.41-1.75). Functional transferrin-binding assays confirmed sexually dimorphic binding in resected patient samples indicating underlying differences in iron biology. Anemia among glioblastoma patients exhibits a sex-specific association with survival.

Optimizing Preoperative Chronic Pain Management in Elective Spine Surgery Patients: A Narrative Review of Outcomes with Opioid and Adjuvant Pain Therapies

» Chronic preoperative opioid use negatively affects outcomes after spine surgery, with increased complications and reoperations, longer hospital stays, decreased return-to-work rates, worse patient-reported outcomes, and a higher risk of continued opioid use postoperatively.» The definition of chronic opioid use is not consistent across studies, and a more specific and consistent definition will aid in stratifying patients and understanding their risk of inferior outcomes.» Preoperative weaning periods and maximum dose thresholds are being established, which may increase the likelihood of achieving a meaningful improvement after surgery, although higher level evidence studies are needed.» Spinal cord stimulators and intrathecal drug delivery devices are increasingly used to manage chronic back pain and are equivalent or perhaps even superior to opioid treatment, although few studies exist examining how patients with these devices do after subsequent spine surgery.» Further investigation is needed to determine whether a true mechanistic explanation exists for spine-related analgesia related to spinal cord stimulators and intrathecal drug delivery devices.

Long-term Outcomes in Use of Opioids, Nonpharmacologic Pain Interventions, and Total Costs of Spinal Cord Stimulators Compared With Conventional Medical Therapy for Chronic Pain

Importance

Spinal cord stimulators (SCSs) are increasingly used for the treatment of chronic pain. There is a need for studies with long-term follow-up.

Objective

To determine the comparative effectiveness and costs of SCSs compared with conventional medical management (CMM) in a large cohort of patients with chronic pain.

Design, Setting, and Participants

This was a 1:5 propensity-matched retrospective comparative effectiveness research analysis of insured individuals from April 1, 2016, to August 31, 2018. This study used administrative claims data, including longitudinal medical and pharmacy claims, from US commercial and Medicare Advantage enrollees 18 years or older in Optum Labs Data Warehouse. Patients with incident diagnosis codes for failed back surgery syndrome, complex regional pain syndrome, chronic pain syndrome, and other chronic postsurgical back and extremity pain were included in this study. Data were analyzed from February 1, 2021, to August 31, 2022.

Exposures

SCSs or CMM.

Main Outcomes and Measures

Surrogate measures for primary chronic pain treatment modalities, including pharmacologic and nonpharmacologic pain interventions (epidural and facet corticosteroid injections, radiofrequency ablation, and spine surgery), as well as total costs.

Results

In the propensity-matched population of 7560 patients, mean (SD) age was 63.5 (12.5) years, 3080 (40.7%) were male, and 4480 (59.3%) were female. Among matched patients, during the first 12 months, patients treated with SCSs had higher odds of chronic opioid use (adjusted odds ratio [aOR], 1.14; 95% CI, 1.01-1.29) compared with patients treated with CMM but lower odds of epidural and facet corticosteroid injections (aOR, 0.44; 95% CI, 0.39-0.51), radiofrequency ablation (aOR, 0.57; 95% CI, 0.44-0.72), and spine surgery (aOR, 0.72; 95% CI, 0.61-0.85). During months 13 to 24, there was no significant difference in chronic opioid use (aOR, 1.06; 95% CI, 0.94-1.20), epidural and facet corticosteroid injections (aOR, 1.00; 95% CI, 0.87-1.14), radiofrequency ablation (aOR, 0.84; 95% CI, 0.66-1.09), or spine surgery (aOR, 0.91; 95% CI, 0.75-1.09) with SCS use compared with CMM. Overall, 226 of 1260 patients (17.9%) treated with SCS experienced SCS-related complications within 2 years, and 279 of 1260 patients (22.1%) had device revisions and/or removals, which were not always for complications. Total costs of care in the first year were $39 000 higher with SCS than CMM and similar between SCS and CMM in the second year.

Conclusions and Relevance

In this large, real-world, comparative effectiveness research study comparing SCS and CMM for chronic pain, SCS placement was not associated with a reduction in opioid use or nonpharmacologic pain interventions at 2 years. SCS was associated with higher costs, and SCS-related complications were common.

Sigmoid volvulus: Evaluating identification strategies and contemporary multicenter outcomes

BACKGROUND

There is limited epidemiologic data on sigmoid volvulus (SV) from non-endemic regions. Therefore, we performed a multicenter study to report contemporary outcomes and appraise literature-based methods that pair diagnostic and procedural codes to identify SV.

METHOD

Using an automated search for patients with 'volvulus' in our system from 2011 to 2021, we reviewed electronic charts to clarify the diagnosis, automatically replicate three strategies to identify SV, and retrieved 6-month outcomes.

RESULTS

Of 895 patients, 109 had SV. Literature-based strategies poorly identified SV. At the index admission, patients underwent endoscopic reduction alone (33%), emergent (16.5%), semi-elective (34%), or elective (16.5%) surgery. Endoscopic reduction alone had high recurrence rates and delayed surgery was associated with worse outcomes.

CONCLUSION

Literature-based strategies to identify SV suffer from misclassification bias which affects patient counseling. In this large series, one-third of patients do not undergo during their index admission despite improved outcomes with earlier surgery.

The impact of spinal cord stimulation on opioid utilization in failed back surgery syndrome and spinal surgery naïve patients

Background

Spinal cord stimulation (SCS) has been utilized for failed back surgery syndrome (FBSS) with well-documented improvements in pain and function. However, limited studies have investigated the relationship between spinal surgery, SCS and opioid use outcomes.

Methods

A narrative review utilizing the scale for the quality assessment of narrative review articles (SANRA) methodology looking at trials involving SCS and opiates.

Results

Twenty-six studies met inclusion criteria. Surgery-naïve subjects had the greatest mean opioid dose reduction of 50.39% morphine milliequivalents, and the greatest number of patients who discontinued opioids at 53.72%. No statistical analysis was performed due to heterogeneous data.

Conclusion

SCS has a positive impact on opioid reduction, regardless of prior spinal surgical history. However, due to a lack of homogenous data, a formal conclusion comparing outcomes between spinal surgical histories cannot be drawn. There is an inherent difficulty in evaluating this topic given its complexity and multifactorial origin. Studies would require collaboration between pain physicians, societies and industry. Even then, patient biases such as psychological and expectation would be difficult to account for. This topic remains an ongoing challenge for interventional pain physicians.