OBJECTIVE:To investigate whether thoracic spinal canal and cord anatomy, as visualized on preoperative magnetic resonance imaging (MRI), predicts pain outcomes following spinal cord stimulation (SCS) for chronic pain. METHODS:A retrospective review identified 70 patients who underwent thoracic percutaneous SCS implantation between 2016 and 2024 with ≥ 12 months of follow-up. Preoperative T1-weighted and T2-weighted MRI scans were used to measure anatomical parameters at T8 and T9 levels, including dorsal canal distance, dorsal cerebrospinal fluid layer thickness, and percentage of free canal area. Patients were categorized as "successful" or "unsuccessful" based on ≥ 50% pain reduction documented in follow-up visits. Associations between anatomical measurements, SCS outcomes, lead migration, and surgical duration were analyzed. RESULTS:Of 70 patients, 61.4% achieved successful pain relief. No significant differences were found in spinal canal dimensions between success and failure groups. Stratification into "small" and "large" anatomical subgroups similarly showed no significant association with outcomes. However, a smaller free canal area and dorsal canal triangle area at T8 were modestly associated with increased lead migration (r = -0.345 and -0.306, P < 0.05). No significant relationship was observed between lumbar access parameters and surgical duration. CONCLUSIONS:Preoperative thoracic spinal anatomy, as measured on supine MRI, was not predictive of SCS therapy success. While smaller canal dimensions may increase lead migration risk, they do not appear to affect long-term pain outcomes. These findings support a shift toward dynamic, patient-specific, and computational models for improving SCS efficacy and patient selection.

This manuscript introduces the latest generation of a patient-mounted platform designed for segmental injections of therapeutics direct into the spinal cord parenchyma. It emphasizes its importance and it presents the rationale for developing this delivery methodology. It compares the newest with the previous generations, detailing how the modifications can streamline transportation, assembly, sterilization, and utilization of the platform by different surgeons. Finally, the illustrations depict the main alterations, as well as a cadaveric assessment of the device prototype in the cervical and thoracolumbar regions.

Deep brain stimulation is the most advanced and effective neuromodulation therapy for Parkinson disease, essential tremor, and generalized dystonia. This article discusses how imaging improves surgical techniques and outcomes and widens possibilities in translational neuroscience in Parkinson disease, essential tremor, generalized dystonia, and epilepsy. In movement disorders diffusion tensor imaging allows anatomic segment of cortical areas and different functional subregions within deep-seated targets to understand the side effects of stimulation and gain more data to describe the therapeutic mechanism of action. The introduction of visualization of white matter tracks increases the safety of neurosurgical techniques in functional neurosurgery and neuro-oncology.

BACKGROUND: Although deep brain stimulation (DBS) of the subthalamic nucleus (SIN) or globus pallidus internus (GPi) is the surgical method of choice to treat the canonical symptoms of Parkinson disease, occasionally surgical sites become infected or the hardware erodes, necessitating explantation. Usual practice is to remove and reimplant replacement leads after tissue healing, leaving patients without the clinical benefits of DBS for several months, and at risk for DBS withdrawal in some, and some patients are no longer good surgical candidates for reimplantation. Radiofrequency ablation through the DBS lead is an option for these patients. METHODS: We performed a retrospective chart review of all patients who underwent radiofrequency ablation of the STN or GPi through indwelling DBS leads performed before hardware removal at our institution. We generated patient-specific anatomic models to determine lesion locations and volumes. RESULTS: Six patients underwent radiofrequency ablation of the STN (n = 4) and GPi (n = 2) through indwelling DBS leads. All 6 of these patients initially showed comparable motor symptom relief to that experienced with DBS before lesioning, with 4 patients sustaining meaningful long-term (>= 2 years) improvement. Better outcomes were achieved in those patients with a higher percentage of the planned target lesioned. CONCLUSIONS: Radiofrequency ablation through indwelling DBS leads before explantation could be considered a viable alternative to subsequent reimplantation or stereotactic lesion in patients with Parkinson disease in whom hardware explantation is necessary, if the patient achieved substantive symptom relief with DBS. This approach avoids symptom exacerbation while awaiting revision surgery.

Abstract Essential tremor can be a disabling condition that manifests with postural and action tremors. Hence, patients with essential tremor have difficulty performing basic activities of daily living, including eating and drinking. Though medical therapies such as beta-blockers and primidone may provide some degree of relief for patients, a subset of patients do not experience improvement with medical therapy. Deep brain stimulation targeting the ventralis intermedius nucleus of the thalamus is an effective intervention for essential tremor. Stimulation-induced side effects can include paresthesia from stimulation of the sensory thalamus and motor effects from stimulation of the internal capsule. Evidence supports performing surgery either with patients awake using intraoperative electrophysiological testing or with patients asleep using intraoperative radiological confirmation.

OBJECTIVE:Deep brain stimulation (DBS) is an effective procedure in improving motor symptoms for patients with advanced Parkinson's disease (PD) through the use of high-frequency stimulation. Although one of the most commonly used target sites for DBS, sensorimotor regions of the globus pallidus interna (GPi) have yet to be thoroughly described with advanced neuroimaging analysis in vivo for human subjects. Furthermore, many imaging studies to date have been performed in a research setting and bring into question the feasibility of their applications in a clinical setting, such as for surgical planning. This study compares two different tractography methods applied to clinically feasible acquisition sequences in identifying sensorimotor regions of the GPi and the subthalamic nucleus (STN) in patients with advanced PD selected to undergo DBS. METHODS:Seven patients with refractory PD selected for DBS were examined by MRI. Diffusion images were acquired with an average acquisition time of 15 minutes. Probabilistic and deterministic tractography methods were applied to each diffusion-weighted data set using FSL and MRtrix, respectively. Fiber assignment was performed using combined sensorimotor areas as initiation seeds and the STN and GPi, separately, as inclusion masks. Corticospinal tracts were excluded by setting the cerebral peduncles as exclusion masks. Variability between proposed techniques was shown using center of gravity (CoG) coordinates. RESULTS:Deterministic and probabilistic corticopallidal and corticosubthalamic pathways were successfully reconstructed for all subjects across all target sites (bilaterally). Both techniques displayed large connections between the sensorimotor cortex with the posterolateral aspect of the ipsilateral GPi and the posterosuperolateral aspect of the ipsilateral STN. The average variability was 2.67 mm, with the probabilistic method identifying the CoG consistently more posterior and more lateral than the deterministic method. CONCLUSIONS:Successful delineation of the sensorimotor regions in both the GPi and STN is achievable within a clinically reasonable timeframe. The techniques described in this paper may enhance presurgical planning with increased accuracy and improvement of patient outcomes in patients undergoing DBS. The variability found between tracking techniques warrants the use of the probabilistic tractography method over the deterministic method for presurgical planning. Probabilistic tractography was found to have an advantage over deterministic tractography in its sensitivity, in accurately describing previously described tracts, and in its ability to detect a larger number of fibers.

Parkinson disease (PD) is the second most common neurodegenerative disorder and affects more than 1 million individuals in the United States. Deep brain stimulation (DBS) is one form of treatment of PD. DBS treatment is still evolving due to technological innovations that shape how this therapy is used.

Study Design Observational study using insurance claims. Objective To quantify opioid usage leading up to spinal cord stimulation (SCS) and the potential impact on outcomes of SCS. Setting SCS is an interventional therapy that often follows opioid usage in the care continuum for chronic pain. Methods This study identified SCS patients using the Truven Health MarketScan databases from January 2010 to December 2014. The index event was the first occurrence of a permanent SCS implant. Indicators of opioid usage at implant were daily morphine equivalent dose (MED), number of unique pain drug classes, and diagnosis code for opioid abuse. System explant was used as a measure of ineffective SCS therapy. Multivariate logistic regression was used to analyze the effect of pre-implant medications on explants. Results A total of 5,476 patients (56 ± 14 years; 60% female) were included. SCS system removal occurred in 390 patients (7.1%) in the year after implant. Number of drug classes (odds ratio [OR] = 1.11, P = 0.007) and MED level (5-90 vs < 5 mg/d: OR = 1.32, P = 0.043; ≥90 vs < 5 mg/d: OR = 1.57, P = 0.005) were independently predictive of system explant. Over the year before implant, MED increased in 54% (stayed the same in 21%, decreased in 25%) of patients who continued with SCS and increased in 53% (stayed the same in 20%, decreased in 27%) of explant patients (P = 0.772). Over the year after implant, significantly more patients with continued SCS had an MED decrease (47%) or stayed the same (23%) than before (P < 0.001). Conclusions Chronic pain patients receive escalating opioid dosage prior to SCS implant, and high-dose opioid usage is associated with an increased risk of explant. Neuromodulation can stabilize or decrease opioid usage. Earlier consideration of SCS before escalated opioid usage has the potential to improve outcomes in complex chronic pain.

In the last several years, spinal cord stimulation (SCS) has undergone a revolution with the development of truly different technologies in decades. Although the basic principle remains—the application of electric current to nervous tissue to treat intractable pain—the options for delivery are no longer limited to “traditional” tonic stimulation but also include high frequency (10 kHz), burst, and dorsal root ganglion techniques. This technical revolution has lead to significant and rapid improvement in outcomes and resulted in the advancement of the science. Arguably an effective nonablative, nondestructive therapy such as SCS, whose efficacy can be trialed in a minimally invasive, low morbidity, reversible manner, has never been needed more. The epidemic of chronic spinal pain syndromes continues unabated. The annual cost to US employers is $100 billion per year for spine-related disability1; frame this statistic in the context of the opioid crisis. Currently more deaths per year in the United States are attributable to chronic opioid use than motor vehicle accidents.2,3 Clearly the problems of chronic neck and back pain are ripe for the development and application of new therapeutic strategies. The goals of this special issue are to provide education about this technology by reviewing the available literature in a critical manner. High-quality evidence-based data from level I and II studies are clearly required for the evaluation of any new or evolving treatment. These data are provided in a comprehensive review by Amirdelfan. In an exhaustive review of treatments for chronic spinal pain syndromes, the author notes that strong evidence (level I and II, as noted above) exists supporting the treatment efficacy for active physical therapy and SCS. In addition, the science underpinning this efficacy has been a topic of similarly rigorous investigation. Of particular interest are new data evaluating the role of the ubiquitous glial cell as discussed and analyzed concisely by Vallejo. Obviously the key to successful clinical outcomes is patient selection: which patient will likely benefit from a trial and subsequent implant? The first step is invariably identification of an appropriate diagnostic subgroup with appropriate pathophysiology. One of the more common indications is the “Failed Back Surgical Syndrome,” which, as Kapural points out is far from a discreet diagnosis. Sharan suggests a more precise delineation of diagnostic subgroups while exploring a role for SCS, which strongly suggests expansion of that role. From a practical point of view, Sitzman offers a functional manual of “who to implant” in a compact bullet point format summarizing best practices. This is literally information that could be quickly referenced from any provider's hand held device. Any evidence is only as valuable as its quality and reproducibility. A central theme of this review is criticism. True criticism is positive; in a scientific sense, criticism, according to the Merriam Webster Dictionary is “the activity of making careful judgments about the good and bad qualities of an argument.” This is intended to be a constructive act and frame an idea or theory in the appropriate context and within the appropriate limits. Thus, any discontinuities or gaps in scientific evidence are essential to understand any idea or treatment, a topic addressed by the article of Provenzano. Staats furthers addresses this important concept in his discussion of trial design, and endpoint evaluation. Finally, as we hopefully transition to an era of value-based care, no appraisal of any technology would be complete without a comparative assessment of cost, as addressed by Hoelscher. Interestingly, the apparently high initial cost of the implant is offset by the cost saving entailed by decreased consumption of healthcare resources—due to SCS treatment efficacy—in a relatively short period of time. This of course presumes correct diagnosis, appropriate patient subgrouping, and selection and the use of best practices. Without intense commitment to the science and the process of any intervention, cost in and of itself is a meaningless number, and, unfortunately can be misunderstood, misconstrued, misused, and frankly abused by third-party payers and so called cost containment efforts. To have been invited to be a guest editor for this focus issue has truly been an honor and a pleasure. As someone who has been involved in SCS for more than 25 years, I can enthusiastically state that this is an exciting time for neuromodulation, and promises to be so for the indefinite future. Clearly, there exists a need for more research into the basic science of SCS, and a need for more large levels I and II clinical studies. Although SCS need not be in the armamentarium of all specialties of spine care providers, it deserves nonetheless to be appreciated and understood by all specialties, operative, and nonoperative. One of the keys to successful patient selection is timing: the data presented here argue in favor of prompt consideration of SCS from surgeons who have ruled out further surgery and from pain management specialists when other interventional options have failed. The provider who does not appreciate the increasing impact of SCS is, I fear, truly doing a disservice to their patients and to themselves, and is in some sense, incomplete.

Study Design. Review of published literature pertaining to spinal cord stimulation (SCS) cost data analysis. Objective. To acquire, organize, and succinctly summarize the available literature regarding the costs associated with, and the cost-effectiveness of, SCS. Summary of Background Data. Chronic back and limb pain is a pervasive complaint in modern society, with estimated annual costs of medical care greater than $100 billion. The traditional standard medical management with or without intermittent surgical decompression/fusion has been plagued by high costs and inconsistent results, leading to poor patient satisfaction and functional outcome, and questions from policy makers regarding use of limited healthcare resources. Neuromodulation techniques, including SCS have recently become more common in the treatment of chronic back/leg pain, with clinical studies showing a high degree of efficacy in alleviating otherwise intractable pain. Given the relatively high upfront costs associated with the hardware and implantation, policy makers have, however, questioned their use in the framework of cost-containment and resource utilization. We reviewed the available literature summarizing cost data of SCS in chronic back and limb pain, as an understanding of these data will be vital to justify continued payment for this expensive, but often very effective, treatment modality. Methods. We performed a PubMed literature search utilizing the following terms: “spinal cord stimulation,” “SCS,” “financial,” “cost,” “cost-effectiveness,” and “cost-utility.” All studies published in English and containing complete or partial cost evaluations of SCS for chronic back and limb pain were included. Results. The search revealed 21 studies that evaluated cost data, with or without outcomes analysis and cost-utility analysis, for patients with chronic back and limb pain. The overwhelming majority of data presented shows that SCS is not only an effective treatment option for these patients, but also represents cost savings and efficient use of healthcare resources relative to current standards of care. Although not all studies performed cost-utility analyses, those that did tended to show SCS falling well within accepted thresholds of “willingness-to-pay” on the part of third-party payers. That being said, the articles included in this review were almost all small, retrospective, single-institution studies. In addition, many of them relied on modeling for their analyses, and published literature values for cost and/or outcomes data rather than prospectively collected patient data. Although the data presented in this review are encouraging, it should serve as a foundation for a thorough, prospective, cost-utility analysis of SCS in chronic back and limb pain so that the role of this important treatment modality may be cemented in the treatment paradigm for these patients without questions from third-party payers. Conclusion. The large majority of data covering costs of SCS argue in favor of the cost-effectiveness of this treatment modality for chronic neuropathic pain, especially in comparison to reoperation and medical management. Although most of the higher-quality evidence is relatively short-term, clinical experience with the durability of treatment benefit of SCS in these patients is promising. Given the pushback regarding high upfront costs of implantation, longer-term, prospective, randomized studies evaluating this topic will be important to help maintain third-party payer reimbursements for SCS. Level of Evidence: 5

Surgical intervention is of proven benefit in an appropriately selected subset of patients with medically refractory temporal lobe epilepsy. In these patients, a surgical cure both provides the quality of life improvement that comes from seizure freedom as well as a survival benefit. However, patients who undergo open surgical intervention may have a worsening in neurobehavioral outcomes. Laser interstitial thermal therapy (LITT) represents a minimally invasive surgical intervention that has shown promise in improving post-operative neurobehavioral outcomes. Further, the minimally invasive nature of this procedure holds the possibility to shift the significant under-penetration of surgical intervention that exists for eligible medically refractory patients. Herein, we review open surgical resection-based techniques and the clinical data to date for LITT.

STUDY DESIGN:Topic overview.OBJECTIVE:To describe the varied etiologies resulting in chronic spinal pain and review the current available evidence for treatments.SUMMARY OF BACKGROUND DATA:Chronic pain conditions, especially those that affect the axial back and radiate to the extremities, affect a large population. This results in pronounced disability and a high socioeconomic burden. Our understanding of the underlying mechanisms for chronic pain is limited. This prevents a comprehensive diagnostic approach. Evidence from high-level clinical trials supporting treatments for chronic spinal pain is also limited.METHODS:Articles were identified through PubMed searches or already known to the author. The literature was reviewed and summarized, indicating the strength of evidence available for many treatment modalities.RESULTS:There are very few studies published that evaluate behavioral modifications for chronic spinal pain and only one long-term study investigating chronic pharmacological treatments. The data on the success of spinal surgeries to relieve chronic spinal pain suggest an unacceptably high failure rate. The best evidence (Level I) currently available suggests that spinal cord stimulation is a safe, effective, and durable treatment for chronic spinal pain. Recent clinical data support further investigation of new innovations and earlier therapeutic consideration of currently employed approaches.CONCLUSION:Currently, physicians are limited in the practice of evidence-based medicine regarding chronic spinal pain treatments due to both the paucity of data available and an inconsistent diagnostic nomenclature. The introduction of new neurostimulation modalities is promising but requires better characterization through ongoing prospective clinical investigation.LEVEL OF EVIDENCE:5.

BACKGROUND:Transorbital intracranial penetrating trauma with a retained intracranial foreign body is a rare event lacking a widely accepted diagnostic and therapeutic algorithm. Intraoperative catheter angiography (IOA) has been advocated by some authorities to rule out cerebrovascular injury before and/or after removal of the object, but no standard of care currently exists.CASE DESCRIPTION:A 19-year-old man was involved in a construction site accident whereby a framing nail penetrated the left globe, traversed the lateral bony orbit, and terminated in the midtemporal lobe. No hematoma or injury to the middle cerebral arteries (MCAs) was apparent on noncontrast head computed tomography (CT) or CT angiography, respectively. The foreign body was removed in the operating room under direct visualization after a frontotemporal craniotomy without incident. No significant venous or arterial bleeding was encountered. All visualized MCA branches appeared intact. Indocyanine green videoangiography performed immediately after object removal showed adequate filling of the MCA branches. Given these uneventful clinical and radiographic findings, IOA was not performed. Postoperative head CT and CT angiography showed no obvious neurovascular injury. On postoperative day 2, the patient was noted to have an expressive aphasia. Cerebral angiography showed absent antegrade filling of the angular artery with some retrograde perfusion. Magnetic resonance imaging confirmed an ischemic infarction in the midtemporal lobe. The patient's expressive aphasia improved to near baseline during his hospitalization and he made an excellent clinical recovery.CONCLUSIONS:In transorbital intracranial penetrating trauma with a retained intracranial object, we advocate microsurgical removal of the object under direct visualization followed immediately by IOA. IOA should be strongly considered even in the setting of minimal intraoperative bleeding and normal findings on videoangiography (a course of action that was not followed in the present case). Given that CT angiography and intraoperative videoangiography may miss a potentially treatable traumatic arterial injury, IOA can help determine whether cerebral revascularization may be necessary.

Objective: To test the safety of spinal cord transplantation of human stem cells in patients with amyotrophic lateral sclerosis (ALS) with escalating doses and expansion of the trial to multiple clinical centers. Methods: This open-label trial included 15 participants at 3 academic centers divided into 5 treatment groups receiving increasing doses of stem cells by increasing numbers of cells/injection and increasing numbers of injections. All participants received bilateral injections into the cervical spinal cord (C3-C5). The final group received injections into both the lumbar (L2-L4) and cervical cord through 2 separate surgical procedures. Participants were assessed for adverse events and progression of disease, as measured by the ALS Functional Rating Scale–Revised, forced vital capacity, and quantitative measures of strength. Statistical analysis focused on the slopes of decline of these phase 2 trial participants alone or in combination with the phase 1 participants (previously reported), comparing these groups to 3 separate historical control groups. Results: Adverse events were mostly related to transient pain associated with surgery and to side effects of immunosuppressant medications. There was one incident of acute postoperative deterioration in neurologic function and another incident of a central pain syndrome. We could not discern differences in surgical outcomes between surgeons. Comparisons of the slopes of decline with the 3 separate historical control groups showed no differences in mean rates of progression. Conclusions: Intraspinal transplantation of human spinal cord–derived neural stem cells can be safely accomplished at high doses, including successive lumbar and cervical procedures. The procedure can be expanded safely to multiple surgical centers. Classification of evidence: This study provides Class IV evidence that for patients with ALS, spinal cord transplantation of human stem cells can be safely accomplished and does not accelerate the progression of the disease. This study lacks the precision to exclude important benefit or safety issues.

Rotational vertebral artery occlusion (RVAO) is a well-documented surgically amenable cause of vertebrobasilar insufficiency. Traditionally, patients have been imaged using dynamic rotational angiography. We report a case of RVAO in which intraoperative indocyanine green angiography (ICGA) was used to confirm adequate surgical decompression of the VA. A 57-year-old female who presented with multiple episodes of syncope provoked by turning her head to the right. Rotational dynamic angiography revealed a dominant right VA that became occluded at the level of C5/6 with head rotation to the right. The patient underwent successful surgical decompression of the VA via an anterior cervical approach. ICGA demonstrated VA patency with head rotation. This was further confirmed by intraoperative dynamic catheter angiography. To the best of our knowledge, we present the first use of ICG combined with intra-operative dynamic rotational angiography to document the adequacy surgical decompression of the VA in a patient with RVAO.

OBJECTIVE Esophageal perforation is a rare but well-known complication of anterior cervical spine surgery. The authors performed a systematic review of the literature to evaluate symptomatology, direct causes, repair methods, and associated complications of esophageal injury. METHODS A PubMed search that adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines included relevant clinical studies and case reports (articles written in the English language that included humans as subjects) that reported patients who underwent anterior spinal surgery and sustained some form of esophageal perforation. Available data on clinical presentation, the surgical procedure performed, outcome measures, and other individual variables were abstracted from 1980 through 2015. RESULTS The PubMed search yielded 65 articles with 153 patients (mean age 44.7 years; range 14-85 years) who underwent anterior spinal surgery and sustained esophageal perforation, either during surgery or in a delayed fashion. The most common indications for initial anterior cervical spine surgery in these cases were vertebral fracture/dislocation (n = 77), spondylotic myelopathy (n = 15), and nucleus pulposus herniation (n = 10). The most commonly involved spinal levels were C5-6 (n = 51) and C6-7 (n = 39). The most common presenting symptoms included dysphagia (n =63), fever (n = 24), neck swelling (n = 23), and wound leakage (n = 18). The etiology of esophageal perforation included hardware failure (n = 31), hardware erosion (n = 23), and intraoperative injury (n = 14). The imaging modalities used to identify the esophageal perforations included modified contrast dye swallow studies, CT, endoscopy, plain radiography, and MRI. Esophageal repair was most commonly achieved using a modified muscle flap, as well as with primary closure. Outcomes measured in the literature were often defined by the time to oral intake following esophageal repair. Complications included pneumonia (n = 6), mediastinitis (n = 4), osteomyelitis (n = 3), sepsis (n = 3), acute respiratory distress syndrome (n = 2), and recurrent laryngeal nerve damage (n = 1). The mortality rate of esophageal perforation in the analysis was 3.92% (6 of 153 reported patients). CONCLUSIONS Esophageal perforation after anterior cervical spine surgery is a rare complication. This systematic review demonstrates that these perforations can be stratified into 3 categories based on the timing of symptomatic onset: intraoperative, early postoperative (within 30 days of anterior spinal surgery), and delayed. The most common source of esophageal injury is hardware erosion or migration, each of which may vary in their time to symptomatic manifestation.