Antibiotic-impregnated envelopes reduce the rate of surgical site infection in deep brain stimulation pulse generators: a comparative study.

BACKGROUND AND PURPOSE: Deep brain stimulation (DBS) is a surgical procedure that has been used to treat a variety of neurological disorders including Parkinson's disease, essential tremor, and dystonia. While DBS is generally considered safe and effective, surgical site infections (SSIs) are a potential complication that can lead to significant morbidity and mortality. Our objective was to investigate the use of antibiotic-impregnated envelopes (AIEs) encasing implantable pulse generators (IPGs) to reduce the rate of infection at IPG sites and the costs. METHODS: We conducted a retrospective analysis at a single center encompassing all procedures involving the placement of Implantable Pulse Generators (IPG), including both initial insertions and replacement surgeries. The study period spanned from January 2017 to May 2024. Starting in 2020, the routine utilization of AIE became standard practice at our institute for both primary DBS implantation and IPG replacements. Surgical techniques remained consistent, pre- and post-operative antibiotic protocols were standardized throughout the study period and all cases were undertaken by a single surgeon. RESULTS: 178 patients were included and the overall incidence of IPG SSIs was found to be 1.7% (1 infection in 58 patients; 20 primary IPG/38 IPG replacements) among those who received an AIE compared to 5% (6 infections in 120 patients; 36 primary IPG/84 replacement IPG) in patients where no AIE was utilized. This resulted in an odds ratio for infection that was 2.9 times higher in the absence of AIE. The decrease in infection rates was observed in both primary and replacement IPG implants. Notably, over 80% of patients with IPG infection required surgical intervention. The use of AIE further resulted in significant cost savings. CONCLUSION: To our knowledge, this is the largest series reporting the efficacy of Antibiotic impregnated envelope (AIE) in modifying infection rates associated with both initial and replacement Deep Brain Stimulation (DBS) Implantable Pulse Generators (IPGs). The implementation of AIEs led to a decrease in the occurrence of IPG-related infections, observed across both primary implantations and replacement surgeries, with associated economic benefits.

To scan or not to scan? A retrospective cohort study analysing the efficacy of routine post-operative CT after brain biopsy.

PURPOSE: Postoperative management following elective cranial surgery, particularly after biopsy procedures, varies significantly across neurosurgical centres. Routine postoperative head CT scans, traditionally performed to detect complications such as intracranial bleeding or cerebral oedema, lack substantial evidence supporting their necessity. METHODS: This study is a retrospective cohort analysis conducted at a regional neurosurgical department of 236 patients who underwent brain biopsies between 2018 and 2022. Patient data, including demographics, surgical details, and postoperative outcomes, were collected and analysed. The outcomes investigated were the incidence and impact of postoperative CT scans on time to discharge, management changes, and the influence of preoperative anticoagulation. RESULTS: Out of 236 patients, 205 (86.86%) underwent postoperative CT scans. There was no significant relationship between postoperative hematoma, as detected on a CT scan, and neurological deficit (p = 0.443), or between preoperative anticoagulation and postoperative bleeding on CT scans (p = 0.464). Patients who had postoperative CT scans had a significantly longer length of stay (LOS) compared to those who did not (p < 0.001). Intraoperative bleeding was a predictor of hematoma on postoperative CT (p = 0.017) but not of postoperative neurological deficit. The routine postoperative CT scan showed limited predictive value for symptomatic deficits, with a positive predictive value of 6.67% and a negative predictive value of 96.88%. CONCLUSIONS: Routine postoperative CT scans after brain biopsies do not significantly impact management or improve patient outcomes but are associated with longer hospital stays. CT scans should be reserved for patients showing clinical signs of complications rather than used as a routine procedure after a brain biopsy.

Dual Treatment of Refractory Focal Epilepsy and Obsessive-Compulsive Disorder With Intracranial Responsive Neurostimulation.

Purpose of the Review: Intracranial neurostimulation is a well-established treatment of neurologic conditions such as drug-resistant epilepsy (DRE) and movement disorders, and there is emerging evidence for using deep brain stimulation to treat obsessive-compulsive disorder (OCD) and depression. Nearly all published reports of intracranial neurostimulation have focused on implanting a single device to treat a single condition. The purpose of this review was to educate neurology clinicians on the background literature informing dual treatment of 2 comorbid neuropsychiatric conditions epilepsy and OCD, discuss ethical and logistical challenges to dual neuropsychiatric treatment with a single device, and demonstrate the promise and pitfalls of this approach through discussion of the first-in-human closed-looped responsive neurostimulator (RNS) implanted to treat both DRE (on-label) and OCD (off-label). Recent Findings: We report the first implantation of an intracranial closed-loop neurostimulation device (the RNS system) with the primary goal of treating DRE and a secondary exploratory goal of managing treatment-refractory OCD. The RNS system detects electrophysiologic activity and delivers electrical stimulation through 1 or 2 electrodes implanted into a patient's seizure-onset zones (SOZs). In this case report, we describe a patient with treatment-refractory epilepsy and OCD where the first lead was implanted in the right superior temporal gyrus to target the most active SOZ based on stereotactic EEG (sEEG) recordings and semiology. The second lead was implanted to target the right anterior peri-insular region (a secondary SOZ on sEEG) with the distal-most contacts in the right nucleus accumbens, a putative target for OCD neurostimulation treatment. The RNS system was programmed to detect and record the unique electrophysiologic signature of both the patient's seizures and compulsions and then deliver tailored electrical pulses to disrupt the pathologic circuitry. Summary: Dual treatment of refractory focal epilepsy and OCD with an intracranial closed-loop neurostimulation device is feasible, safe, and potentially effective. However, there are logistical challenges and ethical considerations to this novel approach to treatment, which require complex care coordination by a large multidisciplinary team.

Safety and efficacy of unilateral focused ultrasound pallidotomy on motor complications in Parkinson's disease (PD): a systematic review and meta-analysis.

To systematically review and conduct a meta-analysis to evaluate the safety and efficacy of the unilateral focused ultrasound (FUS) pallidotomy on motor complications in Parkinson's disease (PD) patients. A comprehensive search strategy was implemented through August 15, 2023, and updated on February 13, 2024, across six databases, identifying studies relevant to unilateral focused ultrasound pallidotomy and PD. Eligibility criteria included observational studies, clinical trials, and case series reporting on the impact of the intervention on motor complications in PD patients. The screening and data extraction were done by two independent reviewers. Risk of bias assessment utilized appropriate tools for different study designs. Statistical analysis involved narrative synthesis and meta-analysis. Subgroup analyses and leave-one-out analyses were performed. Five studies were included in our study, involving 112 PD patients undergoing FUS pallidotomy. UPDRS-II analysis revealed a significant improvement from baseline (mean difference (MD): -3.205, 95% CI: -4.501, -1.909, P < 0.001). UPDRS-III overall change was significant (MD: -10.177, 95% CI: [-12.748, -7.606], P < 0.001). UPDRS-IV showed a significant change from baseline (MD: -5.069, 95% CI: [-5.915, -4.224], P < 0.001). UDysRS demonstrated a significant overall improvement (MD: -18.895, 95% CI: [-26.973, -10.818], P < 0.001). The effect of FUS pallidotomy on motor complications in PD patients was effective, with a significant decrease in the UPDRS and UDysRS, reflecting improvement. The incidence of adverse events (headaches, pin-site pain, difficulty walking, and sonication-related head pain) of the FUS pallidotomy was not statistically significant, indicating its safety.

Beta Oscillations in the Sensory Thalamus During Severe Facial Neuropathic Pain Using Novel Sensing Deep Brain Stimulation.

OBJECTIVE: Advancements in deep brain stimulation (DBS) devices provide a unique opportunity to record local field potentials longitudinally to improve the efficacy of treatment for intractable facial pain. We aimed to identify potential electrophysiological biomarkers of pain in the ventral posteromedial nucleus (VPM) of the thalamus and periaqueductal gray (PAG) using a long-term sensing DBS system. MATERIALS AND METHODS: We analyzed power spectra of ambulatory pain-related events from one patient implanted with a long-term sensing generator, representing different pain intensities (pain >7, pain >9) and pain qualities (no pain, burning, stabbing, and shocking pain). Power spectra were parametrized to separate oscillatory and aperiodic features and compared across the different pain states. RESULTS: Overall, 96 events were marked during a 16-month follow-up. Parameterization of spectra revealed a total of 62 oscillatory peaks with most in the VPM (77.4%). The pain-free condition did not show any oscillations. In contrast, ß peaks were observed in the VPM during all episodes (100%) associated with pain >9, 56% of episodes with pain >7, and 50% of burning pain events (center frequencies: 28.4 Hz, 17.8 Hz, and 20.7 Hz, respectively). Episodes of pain >9 indicated the highest relative ß band power in the VPM and decreased aperiodic exponents (denoting the slope of the power spectra) in both the VPM and PAG. CONCLUSIONS: For this patient, an increase in ß band activity in the sensory thalamus was associated with severe facial pain, opening the possibility for closed-loop DBS in facial pain.

Lung injury-induced activated endothelial cell states persist in aging-associated progressive fibrosis.

Progressive lung fibrosis is associated with poorly understood aging-related endothelial cell dysfunction. To gain insight into endothelial cell alterations in lung fibrosis we performed single cell RNA-sequencing of bleomycin-injured lungs from young and aged mice. Analysis reveals activated cell states enriched for hypoxia, glycolysis and YAP/TAZ activity in ACKR1+ venous and TrkB+ capillary endothelial cells. Endothelial cell activation is prevalent in lungs of aged mice and can also be detected in human fibrotic lungs. Longitudinal single cell RNA-sequencing combined with lineage tracing demonstrate that endothelial activation resolves in young mouse lungs but persists in aged ones, indicating a failure of the aged vasculature to return to quiescence. Genes associated with activated lung endothelial cells states in vivo can be induced in vitro by activating YAP/TAZ. YAP/TAZ also cooperate with BDNF, a TrkB ligand that is reduced in fibrotic lungs, to promote capillary morphogenesis. These findings offer insights into aging-related lung endothelial cell dysfunction that may contribute to defective lung injury repair and persistent fibrosis.

Responsive neurostimulation as a therapy for epilepsy following new-onset refractory status epilepticus: Case series and review of the literature.

OBJECTIVE: To report clinical outcomes of patients who presented with new-onset refractory status epilepticus (NORSE), developed drug-resistant epilepsy (DRE), and were treated with responsive neurostimulation (RNS). METHODS: We performed a retrospective review of patients implanted with RNS at our institution and identified three who originally presented with NORSE. Through chart review, we retrieved objective and subjective information related to their presentation, workup, and outcomes including patient-reported seizure frequency. We reviewed electrocorticography (ECoG) data to estimate seizure burden at 3, 6, 12, and 24 months following RNS implantation. We performed a review of literature concerning neurostimulation in NORSE. RESULTS: Use of RNS to treat DRE following NORSE was associated with reduced seizure burden and informed care by differentiating epileptic from non-epileptic events. CONCLUSIONS: Our single-center experience of three cases suggests that RNS is a safe and potentially effective treatment for DRE following NORSE. SIGNIFICANCE: This article reports outcomes of the largest case series of NORSE patients treated with RNS. Since patients with NORSE are at high risk of adverse neuropsychiatric and cognitive sequelae beyond seizures, a unique strength of RNS over other surgical options is the ability to distinguish ictal or peri-ictal from non-epileptic events.

Improving Quality Care and Patient Safety With Implementation of an Oversew Stitch in Lumbar Drains.

ABSTRACT: The lumbar drain exit site purse string oversew stitch is a well-described bedside intervention to stop or prevent cerebrospinal fluid (CSF) leak. It is not routinely placed at the time of lumbar drain placement. Via four plan-do-study-act (PDSA) cycles, we test the effect of prophylactic utilization of the lumbar drain exit site oversew stitch on house officers' paging burden, need to redress the drain, need to oversew the drain to stop a CSF leak, and need to replace the drain. We found that the simple act of placing an oversew stitch at the time of lumbar drain placement significantly reduced paging burden and reduced the frequency at which an oversew stitch was required to stop a CSF leak. Subjectively, during PDSA cycles during which overstitches were placed prophylactically, in-house residents perceived that there were less lumbar drains on service, although objectively, the overall number was unchanged. We conclude that prophylactic lumbar drain exit site stitch placement reduces risk and bedside interventions for patients and also reduces overall call burden on house officers. This simple intervention may therefore provide a more widespread improvement in care quality beyond lumbar drain care because house officers experience less burnout during their call shifts.

Flexible, scalable, high channel count stereo-electrode for recording in the human brain.

Over the past decade, stereotactically placed electrodes have become the gold standard for deep brain recording and stimulation for a wide variety of neurological and psychiatric diseases. Current electrodes, however, are limited in their spatial resolution and ability to record from small populations of neurons, let alone individual neurons. Here, we report on an innovative, customizable, monolithically integrated human-grade flexible depth electrode capable of recording from up to 128 channels and able to record at a depth of 10 cm in brain tissue. This thin, stylet-guided depth electrode is capable of recording local field potentials and single unit neuronal activity (action potentials), validated across species. This device represents an advance in manufacturing and design approaches which extends the capabilities of a mainstay technology in clinical neurology.

Modular Phoneme Processing in Human Superior Temporal Gyrus.

Modular organization is fundamental to cortical processing, but its presence is human association cortex is unknown. We characterized phoneme processing with 128-1024 channel micro-arrays at 50-200µm pitch on superior temporal gyrus of 7 patients. High gamma responses were highly correlated within ~1.7mm diameter modules, sharply delineated from adjacent modules with distinct time-courses and phoneme-selectivity. We suggest that receptive language cortex may be organized in discrete processing modules.

Effect of spinal cord stimulation on quality of life and opioid consumption in patients with failed back surgery syndrome.

BACKGROUND: Failed back surgery syndrome (FBSS) is a constellation of conditions occurring after spine surgeries, characterized by the presence of persistent or recurring low back pain that has a significant impact on patients' quality of life. Neuromodulation in the form of Spinal Cord Stimulation (SCS) is considered an indispensable treatment modality in the management of certain chronic pain conditions and it is showing good results for improvement in pain scores and functional capacity of the FBSS patients. OBJECTIVES: To assess the change in pain scores, quality of life, and opioid medication intake as an outcome of neuromodulation procedures performed on patients diagnosed with failed back surgery syndrome, and to detect the post-procedure complications. METHODS: A prospective observational study was conducted at two university hospitals in Egypt and the U.S.A. during the period from September 2019 to August 2021 for patients who underwent spinal cord stimulation procedures for FBSS with follow-up period of at least 1 year. Patients who are 18 years old or older diagnosed with FBSS for more than 6 months and treated with spinal cord stimulation with successful trials during this time frame were included in the study. RESULTS: Thirty-four patients were included in this study who had successful SCS trials and underwent permanent implantation of SCS devices with post-procedure follow-up period of 12 months. Patients showed a median pain numerical rating scale (NRS) of 7/10 at baseline with a median NRS of 4/10 through the follow-up period. Basic mobility and daily activity scores assessed by activity measure of post-acute care (AM-PAC) showed significant improvement from the mean of 16.87 ± 2.74 at baseline to a mean of 19.97 ± 2.93 through follow-up. In addition, there was a reduction in opioid medication usage. Post-procedure complications was of low percentage with the most detected were battery dysfunction in 7 patients and pocket pain in 6 patients. Reoperation was needed in 13 patients with 4 needed just revision and 9 patients required a complete removal of the device. CONCLUSION: Spinal cord stimulation is an effective modality of treatment for cases of failed back surgery syndrome with a statistically significant reduction in pain scores and a significant improvement in quality of life. Also, it achieves a recognizable reduction in opioid analgesic medications, with a reliable safety profile as detected with the recorded post-procedure complications. However, randomized controlled trials with more patients and long-term follow-up are highly recommended.

Responsive deep brain stimulation guided by ventral striatal electrophysiology of obsession durably ameliorates compulsion.

Treatment-resistant obsessive-compulsive disorder (OCD) occurs in approximately one-third of OCD patients. Obsessions may fluctuate over time but often occur or worsen in the presence of internal (emotional state and thoughts) and external (visual and tactile) triggering stimuli. Obsessive thoughts and related compulsive urges fluctuate (are episodic) and so may respond well to a time-locked brain stimulation strategy sensitive and responsive to these symptom fluctuations. Early evidence suggests that neural activity can be captured from ventral striatal regions implicated in OCD to guide such a closed-loop approach. Here, we report on a first-in-human application of responsive deep brain stimulation (rDBS) of the ventral striatum for a treatment-refractory OCD individual who also had comorbid epilepsy. Self-reported obsessive symptoms and provoked OCD-related distress correlated with ventral striatal electrophysiology. rDBS detected the time-domain area-based feature from invasive electroencephalography low-frequency oscillatory power fluctuations that triggered bursts of stimulation to ameliorate OCD symptoms in a closed-loop fashion. rDBS provided rapid, robust, and durable improvement in obsessions and compulsions. These results provide proof of concept for a personalized, physiologically guided DBS strategy for OCD.

Rapid Passive Gamma Mapping as an Adjunct to Electrical Stimulation Mapping for Functional Localization in Resection of Primary Brain Neoplasms.

OBJECTIVE: We examined the utility of passive high gamma mapping (HGM) as an adjunct to conventional awake brain mapping during glioma resection. We compared functional and survival outcomes before and after implementing intraoperative HGM. METHODS: This was a retrospective cohort study of 75 patients who underwent a first-time, awake craniotomy for glioma resection. Patients were stratified by whether their operation occurred before or after the implementation of a U.S. Food and Drug Administration-approved high-gamma mapping tool in July 2017. RESULTS: The preimplementation and postimplementation cohorts included 28 and 47 patients, respectively. Median intraoperative time (261 vs. 261 minutes, P = 0.250) and extent of resection (97.14% vs. 98.19%, P = 0.481) were comparable between cohorts. Median Karnofsky performance status at initial follow-up was similar between cohorts (P = 0.650). Multivariable Cox regression models demonstrated an adjusted hazard ratio for overall survival of 0.10 (95% confidence interval: 0.02-0.43, P = 0.002) for the postimplementation cohort relative to the preimplementation cohort. Progression-free survival adjusted for insular involvement showed an adjusted hazard ratio of 1.00 (95% confidence interval: 0.49-2.06, P = 0.999) following HGM implementation. Falling short of statistical significance, prevalence of intraoperative seizures and/or afterdischarges decreased after HGM implementation as well (12.7% vs. 25%, P = 0.150). CONCLUSIONS: Our results tentatively indicate that passive HGM is a safe and potentially useful adjunct to electrical stimulation mapping for awake cortical mapping, conferring at least comparable functional and survival outcomes with a nonsignificant lower rate of intraoperative epileptiform events. Considering the limitations of our study design and patient cohort, further investigation is needed to better identify optimal use cases for HGM.

Intraoperative application and early experience with novel high-resolution, high-channel-count thin-film electrodes for human microelectrocorticography.

OBJECTIVE: The study objective was to evaluate intraoperative experience with newly developed high-spatial-resolution microelectrode grids composed of poly(3,4-ethylenedioxythiophene) with polystyrene sulfonate (PEDOT:PSS), and those composed of platinum nanorods (PtNRs). METHODS: A cohort of patients who underwent craniotomy for pathological tissue resection and who had high-spatial-resolution microelectrode grids placed intraoperatively were evaluated. Patient demographic and baseline clinical variables as well as relevant microelectrode grid characteristic data were collected. The primary and secondary outcome measures of interest were successful microelectrode grid utilization with usable resting-state or task-related data, and grid-related adverse intraoperative events and/or grid dysfunction. RESULTS: Included in the analysis were 89 cases of patients who underwent a craniotomy for resection of neoplasms (n = 58) or epileptogenic tissue (n = 31). These cases accounted for 94 grids: 58 PEDOT:PSS and 36 PtNR grids. Of these 94 grids, 86 were functional and used successfully to obtain cortical recordings from 82 patients. The mean cortical grid recording duration was 15.3 ± 1.15 minutes. Most recordings in patients were obtained during experimental tasks (n = 52, 58.4%), involving language and sensorimotor testing paradigms, or were obtained passively during resting state (n = 32, 36.0%). There were no intraoperative adverse events related to grid placement. However, there were instances of PtNR grid dysfunction (n = 8) related to damage incurred by suboptimal preoperative sterilization (n = 7) and improper handling (n = 1); intraoperative recordings were not performed. Vaporized peroxide sterilization was the most optimal sterilization method for PtNR grids, providing a significantly greater number of usable channels poststerilization than did steam-based sterilization techniques (median 905.0 [IQR 650.8-935.5] vs 356.0 [IQR 18.0-597.8], p = 0.0031). CONCLUSIONS: High-spatial-resolution microelectrode grids can be readily incorporated into appropriately selected craniotomy cases for clinical and research purposes. Grids are reliable when preoperative handling and sterilization considerations are accounted for. Future investigations should compare the diagnostic utility of these high-resolution grids to commercially available counterparts and assess whether diagnostic discrepancies relate to clinical outcomes.

Analysis of spinal canal diameter in the placement of thoracic spinal cord stimulator paddle leads.

BACKGROUND: Neurologic deficit is known as a rare complication of thoracic spinal cord stimulator (SCS) paddle lead implantation, but many believe its incidence after SCS paddle lead placement is under-reported. It is possible that imaging characteristics may be used to help predict safe paddle lead placement. OBJECTIVE: This imaging study was undertaken to determine the minimum canal diameter required for safe paddle lead placement. METHODS: Patients who underwent thoracic laminotomy for new SCS paddle lead placement from January 2018 to March 2023 were identified retrospectively. Preoperative thoracic canal diameter was measured in the sagittal plane perpendicular to the disc space from T5/6 to T11/12. These thoracic levels were chosen because they span the most common levels targeted for SCS placement. Patients with and without new neurologic deficits were compared using a Mann-Whitney U-test. RESULTS: Of 185 patients initially identified, 180 had thoracic imaging available for review. One (0.5%) and 2 (1.1%) of 185 patients complained of permanent and transient neurologic deficit after thoracic SCS placement, respectively. Patients with neurologic deficits had average canal diameters of <11 mm. The average canal diameter of patients with and without neurologic deficits was 10.2 mm (range 6.1-12.9 mm) and 13.0 mm (range 5.9-20.2), respectively (p < 0.0001). CONCLUSION: Postoperative neurologic deficit is an uncommon complication after thoracic laminotomy for SCS paddle lead placement. The authors recommend ensuring a starting thoracic canal diameter of at least 12 mm to accommodate a SCS paddle lead measuring 2 mm thick to ensure a final diameter of >10 mm. If canal diameter is <12 mm, aggressive undercutting of the lamina, a second laminotomy, or placement of smaller SCS wire leads should be considered.

Responsive neurostimulation as a treatment for super-refractory focal status epilepticus: a systematic review and case series.

OBJECTIVE: Super-refractory status epilepticus (SRSE) has high rates of morbidity and mortality. Few published studies have investigated neurostimulation treatment options in the setting of SRSE. This systematic literature review and series of 10 cases investigated the safety and efficacy of implanting and activating the responsive neurostimulation (RNS) system acutely during SRSE and discusses the rationale for lead placement and selection of stimulation parameters. METHODS: Through a literature search (of databases and American Epilepsy Society abstracts that were last searched on March 1, 2023) and direct contact with the manufacturer of the RNS system, 10 total cases were identified that utilized RNS acutely during SE (9 SRSE cases and 1 case of refractory SE [RSE]). Nine centers obtained IRB approval for retrospective chart review and completed data collection forms. A tenth case had published data from a case report that were referenced in this study. Data from the collection forms and the published case report were compiled in Excel. RESULTS: All 10 cases presented with focal SE: 9 with SRSE and 1 with RSE. Etiology varied from known lesion (focal cortical dysplasia in 7 cases and recurrent meningioma in 1) to unknown (2 cases, with 1 presenting with new-onset refractory focal SE [NORSE]). Seven of 10 cases exited SRSE after RNS placement and activation, with a time frame ranging from 1 to 27 days. Two patients died of complications due to ongoing SRSE. Another patient's SE never resolved but was subclinical. One of 10 cases had a device-related significant adverse event (trace hemorrhage), which did not require intervention. There was 1 reported recurrence of SE after discharge among the cases in which SRSE resolved up to the defined endpoint. CONCLUSIONS: This case series offers preliminary evidence that RNS is a safe and potentially effective treatment option for SRSE in patients with 1-2 well-defined seizure-onset zone(s) who meet the eligibility criteria for RNS. The unique features of RNS offer multiple benefits in the SRSE setting, including real-time electrocorticography to supplement scalp EEG for monitoring SRSE progress and response to treatment, as well as numerous stimulation options. Further research is indicated to investigate the optimal stimulation settings in this unique clinical scenario.

Deciphering spatially distinct immune microenvironments in glioblastoma using ferumoxytol and gadolinium-enhanced and FLAIR hyperintense MRI phenotypes.

Background: MRI with gadolinium (Gd)-contrast agents is used to assess glioblastoma treatment response but does not specifically reveal heterogeneous biology or immune microenvironmental composition. Ferumoxytol (Fe) contrast is an iron nanoparticle that localizes glioblastoma macrophages and microglia. Therefore, we hypothesized that the use of Fe contrast improves upon standard Gd-based T1-weighted and T2/FLAIR analysis by specifically delineating immune processes. Methods: In this, HIPAA-compliant institutional review board-approved prospective study, stereotactic biopsy samples were acquired from patients with treatment-naïve and recurrent glioblastoma based on MR imaging phenotypes; Gd and Fe T1 enhancement (Gd+, Fe+) or not (Gd-, Fe-), as well as T2-Flair hyperintensity (FLAIR+, FLAIR-). Analysis of genetic expression was performed with RNA microarrays. Imaging and genomic expression patterns were compared using false discovery rate statistics. Results: MR imaging phenotypes defined a variety of immune pathways and Hallmark gene sets. Gene set enrichment analysis demonstrated that Gd+, Fe+, and FLAIR+ features were individually correlated with the same 7 immune process gene sets. Fe+ tissue showed the greatest degree of immune Hallmark gene sets compared to Gd+ or Flair+ tissues and had statistically elevated M2 polarized macrophages, among others. Importantly, the FLAIR+ Gd+ and Fe- imaging phenotypes did not demonstrate expression of immune Hallmark gene sets. Conclusions: Our study demonstrates the potential of Fe and Gd-enhanced MRI phenotypes to reveal spatially distinct immune processes within glioblastoma. Fe improves upon the standard of care Gd enhancement by specifically localizing glioblastoma-associated inflammatory processes, providing valuable insights into tumor biology.

Informed Consent for Spine Procedures: Best Practice Guideline from the American Society of Pain and Neuroscience (ASPN).

Introduction: The evolution of treatment options for painful spinal disorders in diverse settings has produced a variety of approaches to patient care among clinicians from multiple professional backgrounds. The American Society of Pain and Neuroscience (ASPN) Best Practice group identified a need for a multidisciplinary guideline regarding appropriate and effective informed consent processes for spine procedures. Objective: The ASPN Informed Consent Guideline was developed to provide clinicians with a comprehensive evaluation of patient consent practices during the treatment of spine pathology. Methods: After a needs assessment, ASPN determined that best practice regarding proper informed consent for spinal procedures was needed and a process of selecting faculty was developed based on expertise, diversity, and knowledge of the subject matter. A comprehensive literature search was conducted and when appropriate, evidence grading was performed. Recommendations were based on evidence when available, and when limited, based on consensus opinion. Results: Following a comprehensive review and analysis of the available evidence, the ASPN Informed Consent Guideline group rated the literature to assist with specification of best practice regarding patient consent during the management of spine disorders. Conclusion: Careful attention to informed consent is critical in achieving an optimal outcome and properly educating patients. This process involves a discussion of risks, advantages, and alternatives to treatment. As the field of interventional pain and spine continues to grow, it is imperative that clinicians effectively educate patients and obtain comprehensive informed consent for invasive procedures. This consent should be tailored to the patient's specific needs to ensure an essential recognition of patient autonomy and reasonable expectations of treatment.