Value Of Spinal Cord Stimulation Research Articles

Impact of spinal cord stimulation on sick leave and disability pension in patients with chronic neuropathic pain: a real-world evidence study in Sweden.

Current research indicates that spinal cord stimulation (SCS) has a positive short-term impact on outcomes, such as quality of life, pain, and productivity in patients with chronic neuropathic pain. However, there is a need for studies on larger population samples. This study used data from Swedish national registers to analyze change and predictors of sick leave and disability pension 2 years before and after SCS treatment. Patients with SCS implanted between 2006 and 2017, and a reference group consisting of 5 individuals matched to each SCS patient without replacement with respect to age, sex, and region of residence, were included. A difference-in-difference approach was used to compare the average change (2 years after treatment vs 2 years before treatment) in net disability days and indirect cost related to disability days for the SCS group, compared with the average change for the reference group. The results showed that SCS treatment in Sweden is associated with a decrease of 21 disability days and consequent decrease in indirect cost of €4127 in working age patients. Large work loss prior to index date was also demonstrated (average 214 days before 1 year), indicating a significant burden on the patient, employers, and the society at large. The number of disability days varied considerably depending on age, sex, socioeconomic variables, and comorbidities; however, the effect of SCS seemed to have little association with patient characteristics. This economic benefit needs to be considered, as well as the clinical outcome, when evaluating the full societal value of SCS.

Predicting the Response of High Frequency Spinal Cord Stimulation in Patients with Failed Back Surgery Syndrome: A Retrospective Study with Machine Learning Techniques.

Despite the proven clinical value of spinal cord stimulation (SCS) for patients with failed back surgery syndrome (FBSS), factors related to a successful SCS outcome are not yet clearly understood. This study aimed to predict responders for high frequency SCS at 10 kHz (HF-10). Data before implantation and the last available data was extracted for 119 FBSS patients treated with HF-10 SCS. Correlations, logistic regression, linear discriminant analysis, classification and regression trees, random forest, bagging, and boosting were applied. Based on feature selection, trial pain relief, predominant pain location, and the number of previous surgeries were relevant factors for predicting pain relief. To predict responders with 50% pain relief, 58.33% accuracy was obtained with boosting, random forest and bagging. For predicting responders with 30% pain relief, 70.83% accuracy was obtained using logistic regression, linear discriminant analysis, boosting, and classification trees. For predicting pain medication decrease, accuracies above 80% were obtained using logistic regression and linear discriminant analysis. Several machine learning techniques were able to predict responders to HF-10 SCS with an acceptable accuracy. However, none of the techniques revealed a high accuracy. The inconsistent results regarding predictive factors in literature, combined with acceptable accuracy of the currently obtained models, might suggest that routinely collected baseline parameters from clinical practice are not sufficient to consistently predict the SCS response with a high accuracy in the long-term.

The Added Value of High Dose Spinal Cord Stimulation in Patients with Failed Back Surgery Syndrome after Conversion from Standard Spinal Cord Stimulation.

Patients with Failed Back Surgery Syndrome (FBSS) report a considerably lower health- related quality of life (HRQoL), compared to the general population. Spinal cord stimulation (SCS) is an effective treatment to offer pain relief in those patients. Despite initial treatment success of SCS, its effect sometimes wears off over time. This study investigates the added value of high dose SCS (HD-SCS) in patients with unsatisfactory conventional SCS, from a quality of life perspective. Seventy-eight FBSS patients who were treated with conventional SCS that failed to provide pain relief, were recruited in 15 centers. HRQoL was assessed before converting to HD-SCS (baseline) and three times after converting to HD-SCS using the EuroQol-5D-3L. Quality adjusted life years (QALY) were calculated and compared with conventional SCS. An overall significant increase over time was seen in utility values of the EQ5D-3L, as the mean value at baseline 0.283 (±0.21) increased to 0.452 (±0.29) at 12 months of HD-SCS. This average increase in utility coincides with an average increase of 0.153 (±0.24) QALY’s in comparison to continued conventional SCS. Besides the potential of HD-SCS to salvage patients with failed responses to conventional SCS, this treatment seems to be a more efficient treatment than conventional SCS.

High-frequency spinal cord stimulation at 10\u2009kHz for the treatment of painful diabetic neuropathy: design of a multicenter, randomized controlled trial (SENZA-PDN)

BackgroundPainful diabetic neuropathy (PDN), a debilitating and progressive chronic pain condition that significantly impacts quality of life, is one of the common complications seen with long-standing diabetes mellitus. Neither pharmacological treatments nor low-frequency spinal cord stimulation (SCS) has provided significant and long-term pain relief for patients with PDN. This study aims to document the value of 10-kHz SCS in addition to conventional medical management (CMM) compared with CMM alone in patients with refractory PDN.MethodsIn a prospective, multicenter, randomized controlled trial (SENZA-PDN), 216 subjects with PDN will be assigned 1:1 to receive 10-kHz SCS combined with CMM or CMM alone after appropriate institutional review board approvals and followed for 24 months. Key inclusion criteria include (1) symptoms of PDN for at least 12 months, (2) average pain intensity of at least 5 cm—on a 0- to 10-cm visual analog scale (VAS)—in the lower limbs, and (3) an appropriate candidate for SCS. Key exclusion criteria include (1) large or gangrenous ulcers or (2) average pain intensity of at least 3 cm on VAS in the upper limbs or both. Along with pain VAS, neurological assessments, health-related quality of life, sleep quality, and patient satisfaction will be captured. The primary endpoint comparing responder rates (≥50% pain relief) and safety rates between the treatment groups will be assessed at 3 months. Several secondary endpoints will also be reported on.DiscussionEnrollment commenced in 2017 and was completed in 2019. This study will help to determine whether 10-kHz SCS improves clinical outcomes and health-related quality of life and is a cost-effective treatment for PDN that is refractory to CMM.Trial registrationClincalTrials.gov identifier: NCT03228420 (registered 24 July 2017).

Mechanisms of spinal cord stimulation for the treatment of pain: Still in the dark after 50 years.

Background and ObjectiveDespite the value of spinal cord stimulation (SCS) in treating some patients with focal neuropathic pain, technological advances in stimulator design and treatment protocols have not correlated with significant improvements in clinical outcomes. This may be because incomplete understanding of the mechanisms underlying SCS precludes improvement in clinical efficacy. In this brief review, we (a) review phenomenological effects of SCS, (b) review the literature on proposed spinal sites of action of SCS and (c) propose a novel hypothesis of mechanism of action.ResultsDorsal columns, dorsal roots and dorsal horns have each been proposed as spinal sites of action of SCS. We suggest that evidence in favour of the dorsal columns or dorsal roots as the primary mediators of SCS is weak and propose that the dorsal horn is the crucial site of action. Furthermore, we hypothesize that, based on their location, and neurochemical and morphological properties, dorsal horn islet cells may mediate the effects of SCS.ConclusionsThe precise spinal mechanisms of action of SCS are still unknown. Dorsal horn islet cells have properties that position them to play a key role in analgesic effects of electrical stimulation. Understanding the mechanisms responsible for positive SCS effects are needed for successful translation into clinical dividends.SignificanceWe review possible spinal mechanisms of action of spinal cord stimulation for neuropathic pain, proposing that direct modulation of dorsal horn neurons is crucial. We suggest that mechanistic insights are needed for translation into more favourable clinical outcomes.

Complex regional pain syndrome of the foot and its management using spinal cord stimulation

Objective: This article discusses neuropathic foot pain with particular reference to complex regional pain syndrome. It provides recommendations for the clinical evaluation of complex regional pain syndrome and highlights the value of spinal cord stimulation in its management. The aim is to review neuropathic foot pain in complex regional pain syndrome and outline its management using spinal cord stimulation. It is important for Podiatrists managing such patients to have an understanding of this treatment modality.Methods: A narrative literature review was undertaken using English language medical databases combining search strategies for complex regional pain syndrome and spinal cord stimulation.Results: Spinal cord stimulation improves the subjective symptoms of the neuropathic foot pain of complex regional pain syndrome, enables objective functional improvement and reduces analgesic consumption.Conclusion: Recent technical developments in spinal cord stimulation have led to improved stimulation patterns adapted to the patients’ needs. Careful preoperative diagnosis, robust patient selection and frequent follow-up are vital for the success of this method.

Therapeutic value of spinal cord stimulation in irritable bowel syndrome: a randomized crossover pilot study.

Irritable bowel syndrome (IBS) is characterized by abdominal pain and changed bowel habits. Spinal cord stimulation (SCS) has been used for treatment of chronic pain syndromes. Animal studies have shown SCS to reduce the reaction to colonic balloon distension, known to be increased in IBS patients. To elucidate the potential for SCS as treatment for IBS, a pilot study was performed. Ten IBS patients (age 26-56 yr) were recruited. A SCS system with a four-polar electrode was implanted at the T5-T8 level. After a 2-wk run-in, a randomized, crossover design SCS during 6 wk was compared with no stimulation, with an ensuing stimulation period for 12 wk; total study period 28 wk. Patients recorded pain level, pain attacks, diarrheas, and global quality of life in a diary. At end of the study patients could choose to retain their SCS system or have it removed. Nine patients completed the whole trial. During stimulation periods the median pain scores were significantly reduced from visual analogue scale (VAS) 7 (4-8) to 3 (2.5-7) and to 4 (2-6) during early and late stimulation periods, respectively (P < 0.03-0.04). Pain attacks were numerically reduced. A few patients reported reduced number of diarrheas. After study termination, six patients chose to retain their SCS system. To conclude, SCS is a minimally invasive treatment option for pain in IBS. With SCS the pain level was reduced though with merely a trend for number of attacks and diarrheas. The efficacy of SCS in IBS pain indicates a possible usefulness in other painful bowel disorders.

Spinal Cord Stimulation in the Treatment of Cancer-Related Pain: “Back to the Origins”

Spinal cord stimulation (SCS) has been used in the treatment of chronic pain for more than 40 years. The most common indication for SCS in the USA is failed back surgery syndrome (FBSS). Interestingly, the first two spinal cord stimulators ever implanted were in patients suffering from bronchogenic carcinoma and pelvic cancer, respectively. While cancer accounts for millions of deaths each year in the USA, pain is often the first sign of malignancy. An increasing number of people suffer from cancer-related pain each year and many receive suboptimal relief. Given the demonstrated value of spinal cord stimulation in the treatment of neuropathic pain, spinal cord stimulation should be considered "earlier" as an adjunct to the treatment of cancer-related pain. In addition, with the improving survival rates associated with advances in cancer treatment, spinal cord stimulation may help reduce the risk of development of chronic neuropathic pain in survivors.

Spinal Cord Stimulation in Patients with Critical Limb Ischernia: A Preliminary Evaluation of a Multicentre Trial

Background: Spinal cord stimulation (SCS) is known to reduce chronic pain. The technique was offered to patients with critical limb ischemia due to atherosclerosis, in which vascular reconstruction was not possible. Methods: 37 patients were randomized for standard treatment with analgesics and vasoactive drugs (n=18) or electrical stimulation of the spinal cord in addition to the standard treatment (n=19). The primary outcome measures were pain relief and limb salvage. Follow-up covered a period of 4 years. Results: Amputation-free survival at 2 years was 39 % for standard treatment and 61 % for the stimulation plus standard treatment (p=0.08, NS). Most amputations occurred within the first year after randomization. Pain relief was statistically significant in favor of the stimulation treatment (p<0.001). None of the patients with good pain relief in the SCS-group was amputated. Limb salvage of this subgroup in the standard treatment was 75 % at one year. Conclusions: A larger multicenter randomized trial comparing SCS and conservative treatment is required to further establish the value of SCS in the treatment of critical limb ischemia. Follow-up of 2 years seems adequate to evaluate the effects of SCS.

Distribution of activity in spinal pathways evoked by experimental dorsal column stimulation.

Experiments were performed in rhesus monkeys to determine the distribution of activity evoked in spinal pathways by dorsal column stimulation. It was shown that many pathways in both the dorsal and ventral quadrants of the cord can be activated either directly or transsynaptically by stimulation with electrodes of the type implanted clinically. Moreover, the transsynaptically evoked responses recorded in each quadrant had somewhat different characteristics. Therefore, since the activation of each group of pathways may have differing effects in modifying the preception of noxious stimuli, the authors believe that changes in electrode position and stimulus parameters may be important in obtaining the therapeutic value of spinal cord stimulation for relief of pain.