Outcomes, complications, and dosing of intrathecal baclofen in the treatment of multiple sclerosis: a systematic review.

OBJECTIVE: The purpose of this systematic review was to evaluate empirical outcomes of studies in the literature that investigated effectiveness of intrathecal baclofen (ITB) in the treatment of multiple sclerosis (MS)-related spasticity (MSRS) based on various metrics. Since the first description of this route of baclofen delivery for MS patients by Penn and Kroin in 1984, numerous studies have contributed to the medical community's knowledge of this treatment modality. The authors sought to add to the literature a systematic review of studies over the last 2 decades that elucidates the clinical impact of ITB in treating MSRS with the following endpoints: impact on patient-centered outcomes, such as spasticity reduction (primary), complications (secondary), and dosing (secondary). METHODS: The authors queried three databases (PubMed, Scopus, and Cochrane Library) using the following search terms: (intrathecal baclofen) AND (multiple sclerosis). The set inclusion criteria were as follows: 1) original, full-text article; 2) written in the English language; 3) published between and including the years 2000 and 2023; 4) discussion of pre- and post-ITB pump implantation outcomes (e.g., reduction in spasticity and improved comfort) in MSRS patients with long-term ITB treatment; and 5) contained a minimum of 5 MS patients. Data on study type, patient demographics, follow-up periods, primary outcomes, and secondary outcomes were extracted from the included studies. RESULTS: The authors' search yielded 465 studies, of which 17 met inclusion criteria. Overall, they found evidence for the effectiveness of ITB in treating MSRS patients whose condition was refractory to oral medications, with significant reported changes in spasm frequency from pre- to postimplantation. They also found evidence supporting the positive impact of ITB on MSRS patients' quality of life. Moreover, the authors found that most complications were surgical rather than pharmacological. In addition, the average 1-year dose of ITB (reported in 7 of the included studies) was 191.93 µg/day, which is substantially lower than ITB doses reported in the literature for patients with central (non-MS) or spinal origins of spasticity at 1-year follow-up. CONCLUSIONS: The evidence supports ITB as a clinically effective treatment for MSRS, particularly in patients in whom oral antispasmodics and physiotherapy have failed. This systematic review contributes a comprehensive synthesis of clinical benefits, complications, and dosing of ITB reported over the past 2 decades, which furthers an understanding of ITB's clinical utility in practice.

Predictors of Skip Laminotomy for Placement of Paddle Leads for Spinal Cord Stimulation.

OBJECTIVES: Placement of a standard paddle lead for spinal cord stimulation (SCS) requires a laminotomy for positioning of the lead within the epidural space. During initial placement, an additional laminotomy or laminectomy, termed a "skip" laminotomy, may be necessary at a higher level to pass the lead to the appropriate midline position. Patient and radiographic factors that predict the need for a skip laminotomy have yet to be identified. MATERIALS AND METHODS: Participants who underwent SCS paddle placement at Albany Medical Center between 2016 and 2017 were identified. Operative reports were reviewed to identify the paddle type, level of initial laminotomy, target level, and skip laminotomy level. Preoperative thoracic magnetic resonance images (MRIs) were reviewed, and spinal canal diameter, interpedicular distance, and dorsal cerebral spinal fluid thickness were measured for each participant when available. RESULTS: A total of 106 participants underwent thoracic SCS placement. Of these, 97 had thoracic MRIs available for review. Thirty-eight participants required a skip laminotomy for placement of the paddle compared with 68 participants who did not. There was no significant difference in demographic features including age, sex, body mass index, and surgical history. Univariate analyses that suggested trends were selected for further analysis using binary logistic regression. Level of initial laminotomy (odds ratio [OR] = 1.51, p = 0.028), spinal canal diameter (OR = 0.71, p = 0.015), and dorsal cerebrospinal fluid thickness (OR = 0.61, p = 0.011) were correlated with skip laminotomy. Target level (OR = 1.27, p = 0.138) and time from trial (1.01, p = 0.117) suggested potential association. The multivariate regression was statistically significant, X2(10) = 28.02, p = 0.002. The model explained 38.3% of the variance (Nagelkerke R2) and predicted skip laminectomy correctly in 73.3% of cases. However, for the multivariate regression, only a decrease in spinal canal diameter (OR = 0.59, p = 0.041) was associated with a greater odds of skip laminotomy. CONCLUSIONS: This study aims to characterize the patient and radiographic factors that may predict the need to perform a skip laminotomy during the initial placement of SCS paddles. Here, we show that radiographic and anatomic variables, primarily spinal canal diameter, play an important role in predicting the need for a skip laminotomy. Furthermore, we suggest that target level for placement and level of initial laminotomy also may contribute. Further investigation of the predictive factors for performing a skip laminotomy would help optimize surgical planning and preoperative patient selection and counseling.

Safety of vagus nerve stimulation and responsive neurostimulation used in combination for multifocal and generalized onset epilepsy in pediatric patients.

OBJECTIVE: The aim of this study was to assess the safety and efficacy of combined active responsive neurostimulation (RNS) and vagus nerve stimulation (VNS) therapies in pediatric patients with drug-resistant epilepsy. METHODS: A single-center retrospective chart review was conducted on pediatric patients implanted with the RNS System with a concomitant active VNS System (VNS+RNS) between 2015 and 2021. Patients with at least 1 month of overlapping concomitant VNS and RNS treatment were included. Patients who had an RNS device implanted after 21 years of age, those who had responsive neurostimulators implanted after their VNS was inactivated, or those in whom the VNS battery died and was not replaced before RNS System implantation were excluded. RESULTS: Seven pediatric VNS+RNS patients were identified, and their courses of treatment were evaluated. All patients tolerated concurrent VNS and RNS treatment well, no device-device interactions were identified, and no major treatment-related adverse effects were noted. The median follow-up after RNS System implantation was 1.2 years. By electroclinical criteria, all 7 patients achieved 75%-99% reductions in the frequency of disabling seizures after RNS System implantation. By patient and caregiver report, 2 patients (28.6%) had 75%-99% reductions in the frequency of their disabling seizures, 2 patients (28.6%) achieved 50%-74% reductions, 2 patients achieved 1%-24% reduction in frequency of disabling seizures, and 1 patient (14.3%) experienced a 1%-24% increase in seizure frequency. The available VNS magnet swipe data identified 2 patients with 75%-99% reductions in seizure frequency as measured by magnet swipes, one with 25%-49% reductions and the other with 1%-24% increases in seizure frequency as measured by magnet swipes. CONCLUSIONS: This study demonstrated that RNS and VNS therapies can safely be used simultaneously in pediatric patients. RNS may potentially augment the therapeutic effects of VNS treatment. Patients in whom a response to VNS has been suboptimal should still be considered for RNS therapy.

Effect of tracheostomy timing in pediatric patients with traumatic brain injury.

BACKGROUND: Traumatic brain injury (TBI) is a prevalent cause of disability and death in the pediatric population, often requiring prolonged mechanical ventilation. Patients with significant TBI or intracranial hemorrhage require advanced airway management to protect against aspiration, hypoxia, and hypercarbia, eventually necessitating tracheostomy. While tracheostomy is much less common in children compared to adults, its prevalence among pediatric populations has been steadily increasing. Although early tracheostomy has demonstrated improved outcomes in adult patients, optimal tracheostomy timing in the pediatric population with TBI remains to be definitively established. OBJECTIVE: This retrospective cohort analysis aims to evaluate pediatric TBI patients who undergo tracheostomy and to investigate the impact of tracheostomy timing on outcomes. DESIGN/METHODS: The Healthcare Cost and Utilization Project (HCUP) Kids' Inpatient Database (KID), collected between in 2016 and 2019, was queried using International Classification of Disease 10th edition (ICD10) codes for patients with traumatic brain injury who had received a tracheostomy. Baseline demographics, insurance status, and procedural day data were analyzed with univariate and multivariate regression analyses. Propensity score matching was performed to estimate the incidence of medical complications and mortality related to early versus late tracheostomy timing (as defined by median = 9 days). RESULTS: Of the 68,793 patients (mean age = 14, IQR 4-18) who suffered a TBI, 1,956 (2.8%) received a tracheostomy during their hospital stay. TBI patients who were tracheostomized were older (mean age = 16.5 vs 11.4 years), more likely to have injuries classified as severe TBIs and more likely to have accumulated more than one indicator of parenchymal injury as measured by the Composite Stroke Severity Scale (CSSS >1) than non-tracheostomized TBI patients. TBI patients with a tracheostomy were more likely to encounter serious complications such as sepsis, acute kidney injury (AKI), meningitis, or acute respiratory distress syndrome (ARDS). They were also more likely to necessitate an external ventricular drain (EVD) or decompressive hemicraniectomy (DHC) than TBI patients without a tracheostomy. Tracheostomy was also negatively associated with routine discharge. Procedural timing was assessed in 1,867 patients; older children (age >15 years) were more likely to undergo earlier placements (p < 0.001). Propensity score matching (PSM) comparing early versus late placement was completed by controlling for age, gender, and TBI severity. Those who were subjected to late tracheostomy (>9 days) were more likely to face complications such as AKI or deep vein thrombosis (DVT) as well as a host of respiratory conditions such as pulmonary embolism, aspiration pneumonitis, pneumonia, or ARDS. While the timing did not significantly impact mortality across the PSM cohorts, late tracheostomy was associated with increased length of stay (LOS) and ventilator dependence. CONCLUSIONS: Tracheostomy, while necessary for some patients who have sustained a TBI, is itself associated with several risks that should be assessed in context of each individual patient's overall condition. Additionally, the timing of the intervention may significantly impact the trajectory of the patient's recovery. Early intervention may reduce the incidence of serious complications as well as length of stay and dependence on a ventilator and facilitate a timelier recovery.

Comparison of Characteristics, Inpatient Outcomes, and Trends in Percutaneous Versus Open Placement of Spinal Cord Stimulators.

OBJECTIVES: Spinal cord stimulation (SCS) is an effective treatment modality for chronic pain conditions for which other treatment modalities have failed to provide relief. Ample prospective studies exist supporting its indications for use and overall efficacy. However, less is known about how SCS is used at the population level. Our objective is to understand the demographics, clinical characteristics, and utilization patterns of open and percutaneous SCS procedures. MATERIALS AND METHODS: The Nationwide Inpatient Sample data base of 2016-2019 was queried for cases of percutaneous or open placement (through laminotomy/laminectomy) of SCS (excluding SCS trials) using International Classification of Disease (ICD), 10th revision, procedure coding system. Baseline demographic characteristics, complications, ICD-Clinical Modification, Diagnosis Related Group, length of stay (LOS), and yearly implementation data were collected. Complications and outcomes were evaluated in total and between the open and percutaneous SCS groups. RESULTS: A total of 2455 inpatients had an SCS placed, of whom 1970 (80.2%) received SCS through open placement. Placement of open SCS was associated with Caucasian race (odds ratio [OR] = 1.671, p < 0.001), private insurance (OR = 1.332, p = 0.02), and age more than 65 years (OR = 1.25, p = 0.034). The most common diagnosis was failed back surgery syndrome (23.8%). Patients with percutaneous SCS were more likely to have a hospital stay of < 1 day (OR = 2.318; 95% CI, 1.586-3.387; p < 0.001). Implant complications during the inpatient stay were positively associated with open SCS placement and reported in 9.4% of these cases (OR = 3.247, p < 0.001). CONCLUSIONS: Patients who underwent open SCS placement were more likely to be older, Caucasian, and privately insured. Open SCS placement showed greater LOS and implant-related complications during their hospital stay. These findings highlight both potential socioeconomic disparities in health care access for chronic pain relief and the importance of increasing age and medical comorbidities as important factors that can influence SCS implants in the inpatient setting.

Socioeconomic characteristics of pediatric traumatic brain injury patients.

BACKGROUND: Traumatic brain injuries (TBIs) play a significant role in pediatric mortality and morbidity. Environment may play a role in the type, severity, and outcome of pediatric TBI (pTBI). Our objective was to characterize the impact of poor socioeconomic status (PSES) on the incidence, treatment, and outcomes of pTBI patients. METHODS: The Kids' Inpatient Database (KID) was queried from 2016 to 2019 for with TBI using International Classification of Disease, 10th revision (ICD 10) codes. Data defining demographics, complications, procedures, and outcomes was extracted. PSES was defined as Medicaid insurance and Q1 median income category. RESULTS: 26,417 patients had pTBI. 11,040 (41.8 %) of pTBI patients were on Medicaid insurance. 13,119 and 8165 (30.9 %) were in Q1 median income category. Land transport caused the majority of pTBI (41 %). Patients on Medicaid or Q1 median income were more likely to experience assault (OR 2.927, CI 95 % 2.455-3.491, p < 0.001 OR 2.033, CI 95 % 1.722-2.4000 p < 0.001 respectively). On propensity matched analysis, PSES was associated with increased mortality (OR 1.667, 95 % CI 1.322-2.100, p < 0.01), length of stay (LOS) (OR 1.369, 95 % CI 1.201-1.559, p < 0.01), and major complicated trauma (OR 1.354 95 % CI 1.090-1.682 p = 0.007). Total hospital charges were higher in pTBI patients on Medicaid ($112,101.52, +/- $203,716.35) versus non-Medicaid ($109,064.37 +/- $212,057.98) (p < 0.001). CONCLUSION: PSES is correlated with increased mortality, complications, and longer LOS. Healthcare coverage and clinical training should take these disparities into account to provide improved care and optimize healthcare resource utilization. LEVEL OF EVIDENCE: Level IV, Retrospective Database.

Responsive Neurostimulation Targeting the Anterior, Centromedian and Pulvinar Thalamic Nuclei and the Detection of Electrographic Seizures in Pediatric and Young Adult Patients.

Background: Responsive neurostimulation (RNS System) has been utilized as a treatment for intractable epilepsy. The RNS System delivers stimulation in response to detected abnormal activity, via leads covering the seizure foci, in response to detections of predefined epileptiform activity with the goal of decreasing seizure frequency and severity. While thalamic leads are often implanted in combination with cortical strip leads, implantation and stimulation with bilateral thalamic leads alone is less common, and the ability to detect electrographic seizures using RNS System thalamic leads is uncertain. Objective: The present study retrospectively evaluated fourteen patients with RNS System depth leads implanted in the thalamus, with or without concomitant implantation of cortical strip leads, to determine the ability to detect electrographic seizures in the thalamus. Detailed patient presentations and lead trajectories were reviewed alongside electroencephalographic (ECoG) analyses. Results: Anterior nucleus thalamic (ANT) leads, whether bilateral or unilateral and combined with a cortical strip lead, successfully detected and terminated epileptiform activity, as demonstrated by Cases 2 and 3. Similarly, bilateral centromedian thalamic (CMT) leads or a combination of one centromedian thalamic alongside a cortical strip lead also demonstrated the ability to detect electrographic seizures as seen in Cases 6 and 9. Bilateral pulvinar leads likewise produced reliable seizure detection in Patient 14. Detections of electrographic seizures in thalamic nuclei did not appear to be affected by whether the patient was pediatric or adult at the time of RNS System implantation. Sole thalamic leads paralleled the combination of thalamic and cortical strip leads in terms of preventing the propagation of electrographic seizures. Conclusion: Thalamic nuclei present a promising target for detection and stimulation via the RNS System for seizures with multifocal or generalized onsets. These areas provide a modifiable, reversible therapeutic option for patients who are not candidates for surgical resection or ablation.

Efficacy of 10 kHz spinal cord stimulation in complex regional pain syndrome: A retrospective analysis.

INTRODUCTION: We examine the clinical efficacy of High Frequency 10 kHz (HF10) spinal cord stimulation (SCS) CRPS patients. MATERIALS AND METHODS: This is a retrospective cohort study of SCS-naïve patients with CRPS treated with HF10-SCS after a successful trial. Patients were evaluated at 2 weeks, 6 weeks, 3 months, and 6 months post-operatively. Outcomes included mean numeric pain rating scale (NRS), mean NRS reduction, NRS percentage improvement (PI), patient reported subjective pain PI (Pain PI), and patients reporting > 50% benefit in symptoms. Pre and post-operative NRS were compared by ordinal regression analysis accounting for the patient's response to the SCS trial. RESULTS: 20 patients met inclusion criteria. 75% were female. Mean age 51 years. Baseline mean NRS was 6.1 for the cohort (1.7). Post-operatively, mean NRS decreased to 4.5 at 2 weeks (p = 0.077), 3.8 at 6 weeks (p = 0.034), 3.7 at 3 months (p = 0.307), and 4.4 at 6 months (p = 0.832). Mean NRS reduction and NRS PI is reported within. Pain PI was 25% at 2 weeks, 55% at 6 weeks, 54% at 3 months, and 53% at 6 months. Greater than 50% reduction in symptoms was reported in 25% of patients at 2 weeks, 85% at 6 weeks, 87% at 3 months, and 64% at 6 months. CONCLUSIONS: HF10 SCS may represent an effective treatment option for reducing objective and subjective symptoms in CRPS that warrants further study.

Intraoperative navigation in surgical management of traumatic spine injury: a propensity score matching analysis.

BACKGROUND: Traumatic spinal injury (TSI) can lead to severe morbidity and significant health care resource utilization. Intraoperative navigation (ION) systems have been shown to improve outcomes in some populations. However, controversy about the benefit of ION remains. To our knowledge, there is no large database analysis studying the outcomes of ION on TSI patients. Here we hope to compare complications and outcomes in patients with TSI undergoing spinal fusion of 3 or more levels with or without the use of ION. METHODS: The 2015-2019 National Surgical Quality Improvement Program (NSQIP) database was queried for cases of posterior spinal instrumentation of 3 or more levels. This population was then selected for postoperative diagnosis consistent with TSI. The effect of prolonged operative time was analyzed for all patients. Propensity score matching analysis was performed to create ION case and non-ION control groups. Baseline demographic characteristics, complications, and outcome data were collected and compared between ION and non-ION groups. RESULTS: A total of 1,034 patients were included in the propensity matched analysis. Among comorbidities, only obesity was significantly more likely in the non-ION group. There was no difference in case complexity between the two groups. ION was associated with higher incidence of prolonged operative time but was a negative independent predictor for sepsis. Prolonged operative time was a significant independent predictor for pulmonary embolism and requirement of transfusion in all patients. Discharge to home, readmission, and reoperation rates did not differ between TSI patients with or without ION. CONCLUSIONS: Use of ION during posterior spinal fusion of 3 or more levels in TSI patients is not associated with worse outcomes. Prolonged operative time, rather than ION, appears to have a higher influence on the rate of complications in this population. Evaluation of ION in the context of specific populations and pathology is warranted to optimize its use.

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.

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.

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.

Spinal Cord Stimulation to Treat Low Back Pain in Patients With and Without Previous Spine Surgery.

OBJECTIVES: Little is known about the effects of spinal cord stimulation (SCS) on chronic low back pain (CLBP) patients with no history of previous spine surgery. Using our prospectively collected database, we evaluate improvements in patients with and without previous spine surgery one-year post SCS implantation. MATERIALS AND METHODS: Subjects completed outcome metrics pre-operatively and one-year post-implantation including Numeric Rating Scale (NRS), McGill Pain Questionnaire (MPQ), Oswestry Disability Index (ODI), Beck's Depression Inventory (BDI), and Pain Catastrophizing Scale (PCS). RESULTS: We enrolled 134 patients; 82 patients had previous spine surgery and 52 patients did not. At one-year post-SCS implantation, patients with previous spine surgery showed improvements in worst pain experienced, least pain experienced, average pain experienced, pain felt currently, MPQ, MPQ sensory, MPQ affective, PCS, PCS helplessness, PCS rumination, PCS magnification, ODI, and BDI scores (p < 0.001, p = 0.005, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p = 0.03, p = 0.01, p = 0.02, p < 0.001, p = 0.05, p < 0.001, p = 0.017, respectively). Likewise, patients without previous spine surgery showed improvements in worst pain experienced, least pain experienced, average pain experienced, pain felt currently, MPQ, MPQ sensory, PCS, PCS helplessness, PCS rumination, PCS magnification, ODI, and BDI scores (p < 0.001, p = 0.005, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p = 0.008, p < 0.001, p < 0.001, respectively). Patients without previous spine surgery showed greater improvements for average pain PCS helplessness (p = 0.01). CONCLUSIONS: Patients with and without previous spine surgery showed similar improvements in pain intensity, pain quality, feelings of rumination and magnification, functional disability, and depression severity. SCS can improve CLBP regardless of whether patients have had previous spine surgery.

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.

Safety of Deep Brain Stimulation Lead Placement on Patients Requiring Anticlotting Therapies.

BACKGROUND: Limited studies exist to support the safety of performing neuromodulation surgeries in patients whose anticlotting medication has been held. Here, we assess the safety of performing deep brain stimulation (DBS) in this patient population. METHODS: All consecutive DBS patients who underwent lead and battery placement/revision at our institution between 2011 and 2020 were included in this Institutional Review Board-approved prospective outcomes database. We retrospectively recorded adverse events occurring within 90 days of surgery. RESULTS: The study included 226 patients who underwent 381 lead placements in 267 surgeries. Of the 267 surgeries included in this study, 176 (66%) were performed on patients not on anticoagulants and 89 (33%) cases were on patients on 1 drug. Two (0.7%) cases involved a patient taking 2 drugs. A total of 49 adverse events were seen. Thirteen occurred in patients taking anticoagulants. There was no difference in adverse event rate between patients on anticlotting medication and those not (χ2 [1] = 1.523, P = 0.2171). No clot-related sequelae occurred in any patient. Three hemorrhages occurred, all in patients not on anticoagulants. CONCLUSIONS: We found no increased risk of complications in patients routinely on anticlotting medication undergoing DBS lead placement. We show that our protocol was successful in balancing increased risks of bleeding and of thromboembolic events in this patient group.

Sex-specific effects of subthalamic nucleus stimulation on pain in Parkinson's disease.

OBJECTIVE: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is known to reduce motor symptoms of Parkinson's disease (PD). The effects of DBS on various nonmotor symptoms often differ from patient to patient. The factors that determine whether or not a patient will respond to treatment have not been elucidated. Here, the authors evaluated sex differences in pain relief after DBS for PD. METHODS: The authors prospectively evaluated 20 patients preoperatively and postoperatively after bilateral STN DBS with the validated numeric rating scale (NRS), Revised Oswestry Disability Index for low-back pain (RODI), and King's Parkinson's Disease Pain Scale (KPDPS) and assessed the impact of sex as a biological variable. RESULTS: The cohort consisted of 6 female and 14 male patients with a mean duration of 11.8 ± 2.0 months since DBS surgery. Females were significantly older (p = 0.02). Covariate analysis, however, showed no effect of age, stimulation settings, or other confounding variables. KPDPS total scores statistically significantly improved only among males (p < 0.001). Males improved more than females in musculoskeletal and chronic subsets of the KPDPS (p = 0.03 and p = 0.01, respectively). RODI scores significantly improved in males but not in females (p = 0.03 and p = 0.30, respectively). Regarding the NRS score, the improvements seen in both sexes in NRS were not significant. CONCLUSIONS: Although it is well recognized that pain complaints in PD are different between men and women, this study is unique in that it examines the sex-specific DBS effects on this symptom. Considering sex as a biological variable may have important implications for DBS pain outcome studies moving forward.

Efficacy of Simultaneous Usage of Spinal Cord Stimulation and Intrathecal Therapy for Nonmalignant Chronic Neuropathic Pain.

BACKGROUND: Some patients with chronic pain and implanted spinal cord stimulators or intrathecal (IT) pumps fail to obtain significant pain relief. The use of dual modality treatment with both therapies is understudied. This study evaluated comprehensive outcomes in this patient population and reported outcomes primarily using IT ziconotide. METHODS: We retrospectively analyzed 11 patients with chronic pain treated with both spinal cord stimulation and IT therapy. When a primary treatment failed to achieve significant pain relief, a secondary device was trialed and implanted. Pain severity (measured by a numeric rating scale) was assessed by the change from baseline to after the first and second intervention. In a subset of patients (n = 6), quality-of-life metrics were also assessed. Outcome measures were analyzed closest to the 1-year follow-up date after implantation of the first modality and then at the most recent follow-up after implantation of the second modality. RESULTS: Spinal cord stimulation leads were percutaneous (n = 2) or paddles (n = 9) and commonly covered T8-10. IT medication included ziconotide (n = 8), baclofen (n = 1), hydromorphone (n = 1), and morphine/clonidine (n = 1). There was a mean of 19.64 ± 3.17 months between primary and secondary intervention. There was a significant improvement in pain severity from baseline to implantation of the second modality (P = 0.032) at a mean follow-up of 50.18 ± 11.83 months. CONCLUSIONS: Dual modality therapy is a potential treatment option in patients who have lost efficacy with a single neuromodulation modality. Further study is required to identify potential responders and nonresponders.

Functional Use of Directional Local Field Potentials in the Subthalamic Nucleus Deep Brain Stimulation.

BACKGROUND: Directional deep brain stimulation (DBS) technology aims to address the limitations, such as stimulation-induced side effects, by delivering selective, focal modulation via segmented contacts. However, DBS programming becomes more complex and time-consuming for clinical feasibility. Local field potentials (LFPs) might serve a functional role in guiding clinical programming. OBJECTIVE: In this pilot study, we investigated the spectral dynamics of directional LFPs in subthalamic nucleus (STN) and their relationship to motor symptoms of Parkinson's disease (PD). METHODS: We recorded intraoperative STN-LFPs from 8-contact leads (Infinity-6172, Abbott Laboratories, Illinois, United States) in 8 PD patients at rest. Directional LFPs were referenced to their common average and time-frequency analysis was computed using a modified Welch periodogram method. The beta band (13-35 Hz) features were extracted and their correlation to preoperative UPDRS-III scores were assessed. RESULTS: Normalized beta power (13-20 Hz) and normalized peak power (13-35 Hz) were found to be higher in anterior direction despite lack of statistical significance (p > 0.05). Results of the Spearman correlation analysis demonstrated positive trends with bradykinesia/rigidity in dorsoanterior direction (r = 0.659, p = 0.087) and with axial scores in the dorsomedial direction (r = 0.812, p = 0.072). CONCLUSION: Given that testing all possible combinations of contact pairs and stimulation parameters is not feasible in a single clinic visit, spatio-spectral LFP dynamics obtained from intraoperative recordings might be used as an initial marker to select optimal contact(s).

Early Experience With New Generation Deep Brain Stimulation Leads in Parkinson's Disease and Essential Tremor Patients.

BACKGROUND: Newer generation deep brain stimulation (DBS) systems have recently become available in the United States. Data on real-life experience are limited. We present our initial experience incorporating newer generation DBS with Parkinson's disease (PD) and essential tremor (ET) patients. Newer systems allow for smart energy delivery and more intuitive programming and hardware modifications including constant current and directional segmented contacts. METHODS: We compared six-month outcomes between 42 newer generation and legacy leads implanted in 28 patients. Two cohorts each included 7 PD patients with bilateral subthalamic nucleus (STN) stimulation and 7 ET patients with unilateral ventral intermediate nucleus (VIM) stimulation of the thalamus. All directional leads included 6172 Infinity 8-Channel Directional leads and Infinity internal pulse generators (Abbott Neuromodulation, Plano, TX, USA) and nondirectional leads included lead 3389 with Activa SC for VIM and PC for STN (Medtronic, Minneapolis, MN, USA). RESULTS: Six-month outcomes for medication reduction and motor score improvements between new and legacy DBS systems in PD and ET patients were similar. Directionality was employed in 1/3 of patients. Therapeutic window (difference between amplitude when initial symptom relief was obtained and when intolerable side effects appeared with the contact being used) was significantly greater in new DBS systems in both PD (p = 0.005) and ET (p = 0.035) patients. The windows for new and legacy systems were 3.60 V ± 0.42 and 2.00 V ± 0.32 for STN and 3.06 V ± 0.44 and 1.85 V ± 0.28 for VIM, respectively. DISCUSSION: The therapeutic window of newer systems, whether or not directionality was used, was significantly greater than that of the legacy system, which suggests increased benefit and programming options. Improvements in hardware and programming interfaces in the newer systems may also contribute to wider therapeutic windows. We expect that as we alter workflow associated with newer technology, more patients will use directionality, and amplitudes will become lower.

Intrathecal Pain Therapy for the Management of Chronic Noncancer Pain.

Intrathecal drug delivery has been well established an effective and safe method for the treatment of pain, including palliative cancer-related and chronic nonmalignant pain. In this article, we discuss the role of intrathecal pain therapy in the management of chronic, refractory nonmalignant pain. Common indications, patient selection criteria, medication options, complications, and adverse events are discussed within the context of results from randomized controlled trials, clinical consensus guidelines, and best available literature to date.