Prevalence of pain phenotypes and co-morbidities of chronic pain in Parkinson's Disease.

OBJECTIVE: The prevalence of chronic pain in Parkinson's disease (PD) in neurology practices ranges from 24 % to 83 %. To determine whether this prevalence is accurate across patients with PD, we leveraged data from electronic medical records in 80 inpatient and outpatient general practice settings. METHODS: We explored the prevalence of chronic pain in patients with PD relative to age and sex-matched controls in a large international database with electronic medical records from over 250 million patients (TriNetX Cambridge, MA, USA). We described demographics, co-morbid conditions and medication differences between patients with PD and without PD who have chronic pain. RESULTS: Extracted data included 4510 patients with PD and 4,214,982 age-matched control patients without Parkinson's Disease. A chronic pain diagnosis was identified in 19.3 % of males and 22.8 % of females with PD. This differed significantly from age-matched patients without PD who had a significantly lower prevalence of chronic pain 3.78 % and 4.76 %. Significantly more PD patients (both male and females) had received tramadol, oxycodone, and neuropathic agents (p<0.001) than patients without PD. Females with PD more often received anti-depressants than males with PD (p<0.05), corresponding with a significantly higher prevalence of depression. CONCLUSION: Chronic pain in patients with PD is five times as common as in age-matched controls in general practice settings. Patients with PD have a greater prevalence of comorbid conditions that affect development of chronic pain. Whether the pain or the PD is causative to those conditions remains to be elucidated.

Correlating Evoked Electromyography and Anatomic Factors During Spinal Cord Stimulation Implantation With Short-Term Outcomes.

INTRODUCTION: We examine ways intraoperative neuromonitoring during spinal cord stimulation (SCS) varies between a high-resolution investigational SCS (HR-SCS) paddle and a commercial paddle. Furthermore, the presence of evoked motor responses (eg, electromyography [EMG]) in painful regions during surgery is correlated to outcomes. MATERIALS AND METHODS: We used HR-SCS to assess EMG response from 18 patients (NCT05459324). Maximum percentage change in root mean squared (maxRMS) EMG values was determined. Correlations were performed with magnetic resonance imaging measurements and patient outcomes collected preoperatively and at three months (numerical rating scale [NRS], McGill Pain, Beck Depression Inventory, Oswestry Disability Index [ODI], and Pain Catastrophizing Score). RESULTS: Of the 18 patients (12 women to six men; mean age 56 years; eight with neuropathic pain, eight with persistent spinal pain syndrome, two with complex regional pain syndrome), nine had a response at three months based on 50% reduction in NRS, 14 by achieving minimal clinically important difference (MCID) on NRS, and 11 by reaching MCID on ≥three outcome metrics. The anterior posterior diameter (APD) of the spinal column at level of testing correlated with all three responses (p < 0.05). We examined RMS at muscles correlating with individual patient pain distributions and found correlations between RMS and MCID NRS and MCID ODI (p < 0.05). maxRMS in abductor hallucis correlated with improvement in NRS and ODI across the group (p < 0.05). CONCLUSIONS: We found that eliciting EMGs over the painful areas during surgery caused alleviation of pain intensity and disability. Obtaining stimulation of abductor hallucis (AH) was more predictive of pain improvement than any other muscle group, and APD alone correlated with improvements in pain intensity and holistic outcomes. These pilot data suggest that implanters should consider APD and EMG responses from painful regions and AH during surgery.

Improved Selectivity in Eliciting Evoked Electromyography Responses With High-Resolution Spinal Cord Stimulation.

BACKGROUND AND OBJECTIVES: As spinal cord stimulation (SCS) offers a therapy for increasing numbers of patients with chronic pain and spinal cord injury, it becomes increasingly important to better understand its somatotopy. In this prospective study, we investigate whether high-resolution SCS (HR-SCS) offers improved selectivity assessed through elicitation of evoked electromyography (EMG) responses as compared with commercial paddle leads. METHODS: Vertical tripole configurations were used to elicit EMG responses in both types of paddles placed for standard-of-care indications between T6 and T10. In HR-SCS, evoked EMG responses in lower extremity/abdominal muscle groups were monitored at 6 to 8 mediolateral sites. All commercial paddle columns were tested. Percentage change in the maximum root mean square value was calculated at a group level. Heat maps were generated to identify responders for each muscle group. Responders were considered patients who had a >50% change in root mean square over baseline. RESULTS: We demonstrated significantly greater motor responses across medial and lateral contacts and greater responder rates consistently at the T6 and T9 levels with HR-SCS as compared with commercial paddles in 18 patients. Distal muscle groups (gastrocnemius and tibialis anterior) and proximal muscle groups (biceps femoris and quadriceps) were selectively activated at both levels. CONCLUSION: We demonstrate that HR-SCS has greater selectivity in eliciting evoked EMG responses in an intraoperative setting. HR-SCS offers recruitment of muscle groups at lateral contacts concurrently with medial contacts. We provide data that HR-SCS may provide higher spatial resolution, which has the potential to allow for personalization of care and treatment of pain syndromes/symptoms which to date have not been effectively treated.

The Evolution of Surgical Technique in Spinal Cord Stimulation: A Scoping Review.

Since the advent of spinal cord stimulation (SCS), its operative technique has consistently advanced. We performed a scoping review of the literature regarding SCS operative techniques to highlight key advancements. To review, summarize, and highlight key changes in SCS implantation techniques since their inception. The authors performed a MEDLINE search inclusive of articles from 1967 to June 2023 including human and modeling studies written in English examining the role of trialing, intraoperative neuromonitoring, and surgical adaptations. Using the Rayyan platform, two reviewers performed a blinded title screen. Of the 960 articles, 197 were included in the title screen, 107 were included in the abstract review, and ultimately 69 articles met inclusion criteria. We examined the utility of trialing and found that historical controls showed significant efficacy, whereas recent results are more equivocal. We discuss the significant improvement in outcomes with intraoperative neuromonitoring for asleep SCS placement. We highlight technique improvements that led to significant reductions in infection, lead migration, and inadequate pain relief. Physicians implanting SCS systems for chronic pain management must continually refine their surgical techniques to keep up with this rapidly evolving therapy. In addition, through collaborative efforts of neuromodulators and industry, SCS is safer and more effective for patients suffering from chronic pain.

Investigation of the intraoperative cortical responses to spinal motor mapping in a patient with chronic pain.

Intraoperative neurophysiological monitoring (IONM) in spinal cord stimulation (SCS) surgery for chronic pain is shown to provide effective guidance during device placement. Electromyography (EMG) is used to determine the laterality of the paddle. In some SCS cases, laterality cannot be obtained via EMG due to patient physiology. Electroencephalography (EEG) is already used in IONM to monitor cortical responses. Here, we show proof-of-concept of assessing the responses of epidurally evoked EMGs simultaneously with EEGs to determine laterality during IONM using a high-resolution (HR) SCS paddle. An 8-column HR-SCS paddle was acutely placed at T9-T10 interspace in patients with failed back surgery syndrome. EMG signals from 18 muscle groups were recorded simultaneously with 60-channel EEG signals at various stimulation amplitudes (0-10 mA). Particular attention was paid to regions associated with pain including the somatosensory cortex (S1), prefrontal cortex (PFC), and motor cortex (M1). When left and right lateral contacts were stimulated at low amplitudes (1-2 mA), significant changes were seen in θ, α, and ß powers in the contralateral PFC but not in M1 or S1. There was a significant correlation between M1 and contralateral contacts in α power. At higher currents (7-8 mA), right-sided contacts resulted in α power change. We found significant differences in α, θ, and ß powers in PFC for contralateral stimulation of the lateral SCS contacts at low amplitudes and in α power at higher amplitudes. The changes in PFC suggest the potential of EEG for understanding a cortical mechanism of action of SCS and provide insight into the pathophysiology of chronic pain.NEW & NOTEWORTHY Here, we present proof of concept of assessing the responses of epidurally evoked electromyography simultaneously with scalp electroencephalography to determine whether both laterality and insights into pain mechanisms can be elucidated. With stimulation, significant changes were seen in θ, α, and ß band power in the contralateral prefrontal cortex and in α power in the motor cortex. We provide insight into the mechanism of action of SCS in preventing pain in this patient.

MR thermometry imaging for low intensity focused ultrasound modulation of spinal nervous tissue.

OBJECTIVES: Previously in rodent and swine models, we have shown that external low intensity focused ultrasound (liFUS) can be used to modulate pain responses. To ensure no adverse heating events occur with liFUS modulation in a non-invasive manner, we perform initial work in swine to show that magnetic resonance thermometry imaging (MRTI) is capable of measuring <2.0 °C changes at the L5 DRG. Further, we show that our device can be constructed in an MR-compatible fashion to minimize artifact. METHODS: Three MRTI techniques (referenceless, corrected proton resonance frequency shift (PRFS), and PRFS) were applied to assess accuracy of detecting thermal changes at the L5 DRG in unheated euthanized swine. A region of interest (ROI) that includes the L5 DRG was delineated, within which MRTI temperature changes were spatially averaged (ground truth 0 °C). In separate experiments with phantoms, B0 field-inhomogeneity, RF transmit (B1+) and fast gradient echo (fSPGR) magnitude images were acquired to downselect liFUS device materials that produce the least MRI artifacts. RESULTS: Referenceless, corrected PRFS, and PRFS MRTI resulted in temperature measurements of 0.8 ± 1.1 °C, 1.1 ± 1.3 °C and 5.2 ± 5 °C, respectively. Both materials caused B0 perturbation but minimal B1+ and MRTI artifacts. The presence of imaging artifacts did not preclude thermal imaging of the region. SIGNIFICANCE: We provide preliminary data suggesting that referenceless MRTI can adequately detect small thermal changes at the DRG that may occur with neuromodulation, which is one of the first steps in creating a table of safe parameters for liFUS therapy in humans.

Perceptions of pain in aging females undergoing spinal cord stimulation.

Aim: Effects of age and sex on chronic pain outcomes following spinal cord stimulation (SCS) have not yet been assessed. Methods: We retrospectively reviewed 1 year outcomes from a database of patients receiving thoracic SCS. Subjects were divided into four cohorts: pre-menopausal and post-menopausal females, and aged-matched males. Improvement using the numerical rating scale, Oswestry Disability Index (ODI), Beck's Depression Inventory (BDI), McGill Pain Questionnaire and Pain Catastrophizing Scale (PCS) was assessed. Results: Older females were notably different from males and females under 60 as they had greater improvements in ODI, BDI and PCS. Further, females ≥60 had greater improvement in PCS compared with males ≥60. Conclusion: Our findings suggest greater improvement with 1 year SCS treatment in post-menopausal females, compared with age-matched males.

Spinal cord stimulation (SCS) has been shown to be an effective treatment for chronic pain that does not respond to other therapies. It is well recognized that men and women differ in how they perceive pain and how they respond to pain treatments. However, whether women who are over 60 years old and thus presumed to be menopausal respond differently to SCS has not been evaluated. We looked at our database which collected outcomes related to pain, measured before patients had SCS and 1 year after SCS. We found that women over 60 responded better to SCS treatment. They experienced significantly greater improvements in the disability, depression and catastrophizing associated with their pain than did women under 60. Further SCS resulted in more improvements in catastrophizing in women over 60 than in men over 60. Taken together, our hope is that these data help physicians to determine the best patients for SCS and to counsel their patients appropriately. To the best of our knowledge, this study is the first to show the impact of sex-specific aging on response to spinal cord stimulation. While we used age as a surrogate for menopause, menopausal status should be documented in the future to confirm that it effects response.

A Pilot Study Comparing Algorithmic Adaptive Conventional Stimulation with High-Dose Stimulation in Chronic Pain Patients.

INTRODUCTION: Spinal cord stimulation is an effective method of treatment for chronic pain. We previously showed that programming using accelerometry was advantageous for paresthesia-based stimulation. However, programming can be labor intensive. OBJECTIVE: Here we focus on standardized programming for both accelerometer-based paresthesia-induced programming (termed "shuffle") and high-dose (HD) subthreshold programming with stimulation delivered over the T9-10 interspace. METHODS: In this prospective cross-over study, patients received 4 weeks of shuffle programming and 4 weeks of HD programming in a randomized order. In both intervals, contacts overlying T9-10 were programmed. Pain scales with measurements of activity and sleep were collected at the end of each study arm and compared with preoperative baseline scores. RESULTS: Twelve patients were enrolled, with 10 patients completing this study. Compared with baseline, during the HD study period, significant improvements were seen in worst pain of week (P = 0.03) and current pain (P = 0.04) as rated on Numeric Rating Scale scores and walking on the Activity Test (P = 0.012). No difference was seen from baseline compared with shuffle stimulation or in shuffle stimulation compared with HD stimulation. CONCLUSION: In this pilot study, we demonstrated that HD stimulation at T9-10 is superior to algorithmic programming of paresthesia-based stimulation. These results compared with our previous work with shuffle suggest that paresthesia-based stimulation may necessitate stimulation of additional contact locations and additional programming to optimize. This algorithmic programming of paresthesia-based stimulation continues to warrant exploration.

High-Resolution Spinal Motor Mapping Using Thoracic Spinal Cord Stimulation in Patients With Chronic Pain.

BACKGROUND: High-resolution spinal cord stimulation (HR-SCS) paddle can stimulate medial-dorsal columns and extend stimulation coverage to the laterally positioned spinal targets. OBJECTIVE: To investigate the medio-lateral selectivity of an HR-SCS paddle in patients with chronic pain. METHODS: During standard-of-care spinal cord stimulation (SCS) placement, epidurally evoked electromyography and antidromic dorsal column-evoked potentials were recorded in 12 subjects using an HR-SCS paddle with 8 medio-lateral sites spanning the full epidural width at thoracic T9-12 and a commercial paddle consecutively. RESULTS: Recruitment maps were aligned with respect to physiological midline which was overlapping with anatomic midline in 10 of 11 cases. Overlapping contacts between the HR-SCS and commercial paddles exhibited similar patterns while HR-SCS demonstrated higher precision targeting of certain dermatomes. Spinal motor maps showed that the lateral contacts triggered stronger responses in medial gastrocnemius, adductor magnus, and tibialis anterior while the medial contacts triggered stronger responses in gluteus maximus and adductor hallucis. The time-locked popliteal fossa responses indicated ipsilateral activation by HR-SCS at the lateral contacts and bilateral activation at the medial contacts with stronger ipsilateral responses. CONCLUSION: This study is the first to perform high-resolution medio-lateral SCS mapping in patients with chronic pain. These results show promise that HR-SCS may provide additional ipsilateral recruitment within the extremities which improve targeting of focal pain in the lower extremities. Furthermore, this study supports the functional use of intraoperative neuromonitoring as a decision tool to determine physiological midline in thoracic SCS surgeries and provides a full methodological framework.

Development of Machine Learning-Based Models to Predict Treatment Response to Spinal Cord Stimulation.

BACKGROUND: Despite spinal cord stimulation's (SCS) proven efficacy, failure rates are high with no clear understanding of which patients benefit long term. Currently, patient selection for SCS is based on the subjective experience of the implanting physician. OBJECTIVE: To develop machine learning (ML)-based predictive models of long-term SCS response. METHODS: A combined unsupervised (clustering) and supervised (classification) ML technique was applied on a prospectively collected cohort of 151 patients, which included 31 features. Clusters identified using unsupervised K-means clustering were fitted with individualized predictive models of logistic regression, random forest, and XGBoost. RESULTS: Two distinct clusters were found, and patients in the cohorts significantly differed in age, duration of chronic pain, preoperative numeric rating scale, and preoperative pain catastrophizing scale scores. Using the 10 most influential features, logistic regression predictive models with a nested cross-validation demonstrated the highest overall performance with the area under the curve of 0.757 and 0.708 for each respective cluster. CONCLUSION: This combined unsupervised-supervised learning approach yielded high predictive performance, suggesting that advanced ML-derived approaches have potential to be used as a functional clinical tool to improve long-term SCS outcomes. Further studies are needed for optimization and external validation of these models.

Does Neuromodulation Reduce Chronic Pain Patient Emergency Department Utilization?

BACKGROUND: Chronic pain (CP) affects roughly 100 million adults in the United States. These subjects present disproportionately to the emergency department (ED). Neuromodulation (NM) has been shown to reduce ED visits longitudinally in subjects. OBJECTIVE: To compare ED utilization rates between subjects with CP with and without NM. METHODS: Subjects with failed back surgery syndrome, complex regional pain syndrome, or neuropathic pain diagnosis who visited the hospital between January 1, 2019, and December 31, 2019, were included. Subjects were divided into a NM-treated cohort and a non-NM cohort. Demographic information, medications, and pain provider visits were obtained. Pain-related ED visits between 2017 and 2019 were compared. RESULTS: A total of 2516 subjects were identified; 291 (11.6%) previously underwent NM. The non-NM cohort had significantly higher rate of pain-related ED visits compared with the NM cohort (15.1% vs 10.0%, P = .018). Younger age (odds ratio [OR] = 0.888 [0.843-0.935]), shorter distance to the hospital (OR = 0.807 [0.767-0.849]), lower household income (OR = 0.865 [0.831-0.901]), opioid use (OR = 1.375 [1.291-1.465]), nonopioid use (OR = 1.079 [1.033-1.128]), and non-NM therapy (OR = 1.751 [1.283-2.390]) were significant predictors of ED visits. Opioid use was the only significant predictor (OR = 6.124 [1.417-26.473]) associated with ED visits in the NM cohort. CONCLUSION: Subjects who underwent NM had fewer visits to the ED when compared with similar subjects who received conventional treatment. Opioid use prompted increased ED utilization in both cohorts. We posit that NM leads to improvement in pain outcomes, integration with multidisciplinary pain specialists, and reduction in severity and frequency of acute pain exacerbations, thereby limiting health care resource utilization.

Association of Outcomes of Spinal Cord Stimulation for Chronic Low Back Pain and Psoas Measurements Based on Size of Iliopsoas Muscles.

INTRODUCTION: Patients experience variable long-term improvement in chronic back pain despite successful spinal cord stimulation (SCS) trials. Iliopsoas (IP) size has been shown to differ between patients with low back pain and healthy controls. In this study, we examine whether the IP muscle cross-sectional area (CSA) is associated with SCS outcomes. MATERIALS AND METHODS: We examined patients for whom we had lumbar MRIs 6.3 years prior to SCS and baseline and one-year outcome data. Percent change from baseline to one year was calculated for Numeric Rating Scale (NRS), Oswestry Disability Index (ODI), Beck Depression Inventory (BDI), Pain Catastrophizing Scale (PCS), and McGill Pain Questionnaire (MPQ). Correlations between IP muscle CSA, ratio of iliopsoas muscle size to the vertebral body area (P/VBA), and the ratio of iliopsoas muscle size to BMI (P/BMI) were examined. Sex differences were considered. RESULTS: A total of 73 subjects were included in this study, including 30 females and 43 males. Males had significantly larger IP (males 15.70 ± 0.58, females 9.72 ± 0.43; p < 0.001), P/VBA (males 1.00 ± 0.04, females 0.76 ± 0.03; p < 0.001), and P/BMI ratio (males 0.51 ± 0.02, females 0.32 ± 0.01; p < 0.001) than females. In females, P/VBA predicted NRS worst pain scores (ß = 0.82, p = 0.004, r2 = 0.55) and BDI (ß = 0.59, p = 0.02, r2 = 0.24). In males, P/BMI was a significant predictor of BDI outcome scores (ß = 0.45, p = 0.03, r2 = 0.16). Males who had more muscle mass measured by iliopsoas size had more depression as measured using BDI (p = 0.03, r = 0.61). Females with less muscle mass measured by P/VBA also experienced more depression (p = 0.02, r = 0.74). CONCLUSIONS: Our study showed that psoas measurements correlated with various pain outcomes specifically. P/VBA was most predictive in females and P/BMI in males. Depression correlated with P/BMI, reinforcing the complex relationship between depression and constant chronic pain. Tertile analyses further showed a relationship between iliopsoas CSA and depression in males and females. We provide preliminary data of sex-specific psoas measurements as a risk factor for worse SCS outcomes.

Age as an Independent Predictor of Adult Spinal Cord Stimulation Pain Outcomes.

INTRODUCTION: Spinal cord stimulation (SCS) is an efficacious chronic pain treatment most commonly used in middle-aged patients. Results from previous studies that investigated SCS' effects in older patient populations have been equivocal. We examine whether SCS outcomes correlate with age. METHODS: We retrospectively examined prospectively collected outcomes from 189 patients who underwent SCS at Albany Medical Center between 2012 and 2020. The patients completed the Numerical Rating Scale (NRS), McGill Pain Questionnaire (MPQ), Oswestry Disability Index (ODI), Beck Depression Inventory (BDI), and Pain Catastrophizing Scale (PCS) preoperatively and 1 year postoperatively. The mean percent change in each outcome was determined and compared via a regression analysis to determine relationships between patient age and each respective outcome metrics. Demographics were compared between patients aged under 65 versus those aged 65 and older via χ2 tests. RESULTS: All subjects demonstrated the expected improvement on NRS, BDI, PCS, and MPQ from baseline to 1-year follow-up, with several demonstrating statistically significant changes: NRS-worst pain (18.66%, p < 0.001), NRS-least pain (26.9%, p < 0.001), NRS-average pain (26.9%, p < 0.01), NRS-current pain (26.4%, p < 0.001), ODI (19.6%, p < 0.001), PCS (29.8%, p < 0.001), and MPQ (29.4%, p < 0.001). There was no significant difference between patients aged under 65 versus those aged 65 and older based on lead type (p = 0.454). Six patients (3.1%) had lead migration, one of whom was 65 or older. Regression analysis revealed improvements in MPQ-sensory and MPQ-affective scores as age increased (p < 0.001, R2 = 0.09; p = 0.046, R2 = 0.05, respectively). Age did not correlate with NRS, ODI, BDI, or PCS. Diagnosis, spinal level of SCS, and lead type were not found to influence any respective outcome measure based on covariate analysis. CONCLUSION: This study represents the largest study where age was correlated to specific pain, depression, and disability outcomes following SCS. We provide evidence that SCS outcomes are equivalent, or better, in older patients following SCS. Based on these findings, SCS is a viable option for treatment of chronic pain in elderly patient populations.

Patient-specific modeling of the volume of tissue activated (VTA) is associated with clinical outcome of DBS in patients with an obsessive-compulsive disorder.

Deep brain stimulation (DBS) promises to treat an increasing number of neurological and psychiatric disorders. DBS outcome is directly a factor of optimal targeting of the relevant brain structures. Computational models can help to interpret a patient's outcome by predicting the volume of tissue activated (VTA) around DBS electrode contacts. Here we report results of a preliminary study of DBS in two patients with obsessive-compulsive disorder and show that VTA predictions, which are based on patient-specific volume conductor models, correlate with clinical outcome. Our results suggest that patient specific VTA calculation can help inform device programing to maximize therapeutic effects and minimize side effects.Clinical Relevance- Patient-specific modeling of the volume of activated tissue can predict clinical outcomes and thus, can help to optimize DBS device programing to maximize therapeutic effects.

Preoperative evaluation of coagulation status in neuromodulation patients.

OBJECTIVE: The incidence of hemorrhage in patients who undergo deep brain stimulation (DBS) and spinal cord stimulation (SCS) is between 0.5% and 2.5%. Coagulation status is one of the factors that can predispose patients to the development of these complications. As a routine part of preoperative assessment, the authors obtain prothrombin time (PT), partial thromboplastin time (PTT), and platelet count. However, insurers often cover only PT/PTT laboratory tests if the patient is receiving warfarin/heparin. The authors aimed to examine their experience with abnormal coagulation parameters in patients who underwent neuromodulation. METHODS: Patients who underwent neuromodulation (SCS, DBS, or intrathecal pump implantation) over a 9-year period and had preoperative laboratory values available were included. The authors determined abnormal values on the basis of a clinical protocol utilized at their practice, which combined the normal ranges of the laboratory tests and clinical relevance. This protocol had cutoff values of 12 seconds and 39 seconds for PT and PTT, respectively, and < 120,000 platelets/µl. The authors identified risk factors for these abnormalities and described interventions. RESULTS: Of the 1767 patients who met the inclusion criteria, 136 had abnormal preoperative laboratory values. Five of these 136 patients had values that were misclassified as abnormal because they were within the normal ranges at the outside facility where they were tested. Fifty-one patients had laboratory values outside the ranges of our protocol, but the surgeons reviewed and approved these patients without further intervention. Of the remaining 80 patients, 8 had known coagulopathies and 24 were receiving warfarin/heparin. The remaining 48 patients were receiving other anticoagulant/antiplatelet medications. These included apixaban/rivaroxaban/dabigatran anticoagulants (n = 22; mean ± SD PT 13.7 ± 2.5 seconds) and aspirin/clopidogrel/other antiplatelet medications (n = 26; mean ± SD PT 14.4 ± 5.8 seconds). Eight new coagulopathies were identified and further investigated with hematological analysis. CONCLUSIONS: New anticoagulants and antiplatelet medications are not monitored with PT/PTT, but they affect coagulation status and laboratory values. Although platelet function tests aid in a subset of medications, it is more difficult to assess the coagulation status of patients receiving novel anticoagulants. PT/PTT may provide value preoperatively.

Can dogs and cats really help our spinal cord stimulation patients?

OBJECTIVES: Pet ownership has been shown to decrease morbidity and mortality in several aspects of health but has not been studied in chronic pain patients. We evaluate whether subjects who underwent spinal cord stimulation (SCS) and own a pet have improved outcomes compared to non-pet owners. METHODS: After obtaining IRB approval, we re-contacted 38 subjects who underwent SCS surgery with preoperative and 1-year postoperative data on Numerical Rating Scale (NRS), McGill Pain Questionnaire (MPQ), Oswestry Disability Index (ODI), Beck Depression Inventory (BDI), and Pain Catastrophizing scale (PCS). We examined influence of pets and pet ownership-specific behaviors on improvement in SCS outcomes. RESULTS: Patients included 24 males/14 females with a mean age of 59.9 ± 11.5 years. At mean follow-up of 12.2 months (range 10-14), there were improvements in NRS, ODI, BDI, PCS and MPQ. Twenty subjects owned pets and 18 did not; all believed pet ownership could improve health. Pet owners improved more on NRS-right now (p = 0.05) and BDI (p = 0.05), and were more satisfied with SCS (p = 0.04). No significant improvement was seen in ODI, MPQ, or PCS. However, PCS did improve in pet owners who exercised their pet (PCS-total, p < 0.01; PCS-helplessness, p < 0.01; PCS-rumination, p = 0.05; PCS-magnification, p = 0.02). CONCLUSIONS: We provide preliminary evidence that pet ownership is associated with improved pain, depression and SCS satisfaction. Exercising with a pet also appears to be beneficial in limiting pain catastrophizing. Pets show promise as a novel means to improve patient SCS outcomes.

Treatment Strategies for Generator Pocket Pain.

OBJECTIVE: Generator site pain is a relatively common phenomenon in patients undergoing spinal cord stimulation (SCS) that complicates management and effective pain relief. This pain may be managed conservatively, with repositioning of the battery and, in some cases, with explant. Here we explore our experience with management of generator site pain ("pocket pain") in a large single-center study. METHODS: All SCS permanent implants and implantable pulse generator (IPG) placements over 9 years were reviewed. Of 785 cases, we identified 43 patients with pocket pain (5.5%). Demographics and treatments of the pocket pain cohort were analyzed. RESULTS: The mean age (± SEM) of the pocket pain cohort was 46.86 ± 1.06, and there were 10/33 males/females. Females were overrepresented in pocket pain cohort (76.7%) when compared with the total SCS cohort (59.0%) (X2 = 5.93, P = 0.015). Diagnosis included failed back surgery syndrome (51.2%), complex regional pain syndrome (23.3%), and chronic neuropathic pain (25.5%). No patients improved with conservative therapy. All patients either went on to revision (n = 23) or explant (n = 20). Time from initial surgery to development of pocket pain was 7.5 months (range: 0.3-88) and from pocket pain to revision surgery was 4.5 months (range: 0.4-26). In addition, significantly more pocket pain patients (65.1%) had workers' compensation (WC) insurance compared with patients without pocket pain (24.9%) (X2 = 33.3, P < 0.001). CONCLUSION: In our institutional experience, pocket pain was inadequately managed with conservative treatments. Being female and having SCS filed under WC increased risk of pocket pain. Future work will explore the nuances in device placement based on body shape and manual activity responsibilities.

Recommendations for Neuromodulation in Diabetic Neuropathic Pain.

Over 50% of the 34 million people who suffer from diabetes mellitus (DM) are affected by diabetic neuropathy. Painful diabetic neuropathy (PDN) impacts 40-50% of that group (8.5 million patients) and is associated with a significant source of disability and economic burden. Though new neuromodulation options have been successful in recent clinical trials (NCT03228420), still there are many barriers that restrict patients from access to these therapies. We seek to examine our tertiary care center (Albany Medical Center, NY, USA) experience with PDN management by leveraging our clinical database to assess patient referral patterns and utilization of neuromodulation. We identified all patients with a diagnosis of diabetes type 1 (CODE: E10.xx) or diabetes type 2 (CODE: E11.xx) AND neuralgia/neuropathic pain (CODE: M79.2) or neuropathy (CODE: G90.09) or chronic pain (CODE: G89.4) or limb pain (CODE: M79.6) OR diabetic neuropathy (CODE: E11.4) who saw endocrinology, neurology, and/or neurosurgery from January 1, 2019, to December 31, 2019. We then determined which patients had received pain medications and/or neuromodulation to divide the cohort into three groups: no treatment, conservative treatment, and neuromodulation treatment. The cohorts were compared with chi-square or one-way ANOVA with multiple comparisons to analyze the differences. A total of 2,635 PDN patients were identified, of which 700 received no treatment for PDN, 1,906 received medication(s), and 29 received neuromodulation (intrathecal therapy, spinal cord stimulation, or dorsal root ganglion stimulation). The patients who received pain medications for PDN visited neurology more often than the pain specialists. Of the patients that received neuromodulation, 24 had seen neurology, 6 neurology pain, and 3 anesthesia pain. They averaged 2.78 pain medications prior to implant. Approximately 41% of the patients in the conservative management group were prescribed three or more medications. Of the 1,935 treated patients, only 1.5% of the patients received neuromodulation. The patients on three or more pain medications without symptomatic relief may be potential candidates for neuromodulation. An opportunity, therefore, exists to educate providers on the benefits of neuromodulation procedures.

Correlation Between Aspects of Perceived Patient Loneliness and Spinal Cord Stimulation Outcomes.

OBJECTIVES: Loneliness as a whole has been characterized as a health-related risk factor and is associated with worse outcomes after cardiac procedures. Evidence suggests that chronic pain patients are particularly vulnerable to feeling lonely. We examined the relationship between different aspects of loneliness and one-year postoperative outcomes after spinal cord stimulation (SCS) for chronic pain. MATERIALS AND METHODS: We contacted 69 patients with thoracic SCS who had participated in our prospective outcomes database with one-year follow-up to complete the validated, abbreviated UCLA Loneliness Scale (UCLA-3). We examined responses on question 9 of the Oswestry Disability Index (ODI), question 12 of the Beck Depression Inventory (BDI), and UCLA-3 due to their relevance to different aspects of loneliness. We conducted regression analyses to determine the relationship between aspects of loneliness and pain outcomes. RESULTS: We identified that loss of interest in people, companionship, and feeling excluded were associated with pain outcomes. Loss of interest in people was associated with improvement in pain (NRS worst p = 0.021, r = 0.32, NRS least p = 0.004, r = 0.4; NRS right now p = 0.016, r = 0.33). Companionship and feeling excluded were also associated with pain. We examined the interface between depression and total loneliness and found that while both were related to each other, depression was not associated with pain outcomes. CONCLUSIONS: This study demonstrates an association between loss of interest in people, companionship, and feeling excluded and worse postoperative pain outcomes after receiving SCS. It identifies aspects of loneliness as important factors to consider when predicting the outcomes of SCS therapy for chronic pain control.