Search

OBJECTIVE Lumbar interbody cage subsidence has a multifactorial etiology. Cage material, although well studied after transforaminal lumbar interbody fusion, has not been investigated as a contributing factor to subsidence after lateral lumbar interbody fusion (LLIF). In this study the authors compared rates of subsidence and reoperation after LLIF between polyetheretherketone (PEEK) and 3D-printed porous titanium (pTi) in an institutional propensity score–matched and cost analysis. METHODS This is a retrospective observational cohort analysis of adult patients who underwent LLIF with pTi versus PEEK between 2016 and 2020. Demographic, clinical, and radiographic characteristics were collected. Propensity scores were calculated and 1:1 matching without replacement of surgically treated levels was performed. The primary outcome of interest was subsidence. The Marchi subsidence grade was determined at the time of last follow-up. Chi-square or Fisher’s exact tests were used to compare subsidence and reoperation rates between lumbar levels treated with PEEK versus pTi. Modeling and cost analysis were performed using TreeAge Pro Healthcare. RESULTS The authors identified a total of 192 patients; 137 underwent LLIF with PEEK (212 levels) and 55 had LLIF with pTi (97 levels). After propensity score matching, a total of 97 lumbar levels remained in each treatment group. After matching, there were no statistically significant differences between groups in baseline characteristics. Levels treated with pTi were significantly less likely to exhibit subsidence (any grade) compared to those treated with PEEK (8% vs 27%, p = 0.001). Five (5.2%) levels treated with PEEK required reoperation for subsidence, but only 1 (1.0%) level treated with pTi required reoperation for subsidence (p = 0.12). Given subsidence and revision rates experienced in the cohorts in this study, the pTi interbody device is economically superior to PEEK in a single-level LLIF as long as its cost is at least $1185.94 lower than that of PEEK. CONCLUSIONS The pTi interbody device was associated with less subsidence, but statistically similar revision rates after LLIF. pTi is potentially a superior economic choice at this study’s reported revision rate.

Lumbar spondylolysis occurs in 5%-8% of adults. This study aimed to report clinical and radiographic outcomes of direct pars repair in adults with lumbar spondylolysis.We conducted a retrospective review of all patients treated for lumbar spondylolysis via open fracture reduction and direct pars repair with cannulated screws using a lag technique. Demographics, clinical presentation, perioperative and intraoperative imaging, and postoperative data were collected. We subsequently performed a systematic review to describe radiographic and clinical outcomes following direct pars repair.Three patients were identified (mean age 40.3 years; range, 21-72 years; 2 male). All patients had bilateral L5 pars fractures treated via open, direct repair with cannulated screws. There were no intraoperative complications. Length of stay was24 hours for each patient. All patients reported back/radicular symptom relief and returned to full-time manual labor by latest follow-up. Noncontrast lumbar computed tomography performed 14-20 months postoperatively confirmed that all patients had good bilateral screw placement without fracture. Two patients (21 and 28 years old at surgery) had evidence of fusion across fracture sites, while 1 patient exhibited radiolucency around the screws and no progression of spondylolisthesis. Additionally, we reviewed 8210 articles and included 15 in a systematic review of direct pars repair. Fusion rates were 67%-100%, with improved average Oswestry Disability Index and visual analog scale back pain scores by latest follow-up.Lumbar spondylolysis treatment with open fracture reduction and direct pars repair with cannulated screws in adults is safe and may result in mechanical back/radicular pain relief, even in the absence of radiographic fusion.

Glioblastoma multiforme (GBM) is an aggressive brain malignancy and harbors a microenvironment limiting immune cells activity. CAR-T cells are being tested in the treatment of cancers and there exist reports which demonstrate dramatic regression of multicentric GBMs following intrathecal treatment with CAR-T cells. In this article, a triple approach for immune treatment of GBM is proposed. First, GBM tumor specimens for each patient will be saved and cultured to obtain tumor lysates. Then, levamisole will be applied, which possesses immunostimulating, anti-glycolytic, and anti-angiogenic features. Following priming the immune system, GBM patients will be injected with lysates of their own tumor cells plus lysates from a GBM cell line, U251. After 3 months of this treatment, CAR-T cells (transduced with IL13Rα2-CAR

Residents in multiple surgical specialties are trained to perform peripheral nerve surgery (PNS), but the extent of exposure to this field varies among specialties. This study evaluates trends in volume of PNS performed during residency for neurologic surgery trainees compared to those in plastic and orthopedic surgery between 2009 and 2019.We queried ACGME for neurologic, plastic, and orthopedic surgery resident case-logs and compared mean number of PNS between graduating residents of each specialty using a one-way analysis of variance test. Linear regression was utilized to determine trends within and across the specialties over the study period.Neurosurgery residents (24.76 ± 3.41) performed significantly fewer PNS than their counterparts in orthopedic (54.56 ± 6.85) and plastic surgery (71.96 ± 12.20), P0.001. Residents in neurologic surgery reported over 1.5-fold as many cases as their ACGME-required minimum, in contrast to plastic (2.5-fold) and orthopedic (5-fold). Plastics residents (3.46 cases/year) demonstrated the greatest longitudinal increase in PNS, followed by neurosurgery residents (0.81 cases/year). PNS accounted for a mean of 5.81% of neurosurgery resident cases, 4.20% of plastic surgery resident cases, and 2.98% of orthopedic surgery resident cases (P0.001).Neurosurgery residents exceeded the required minimum number of PNS and were increasingly more exposed to PNS. However, compared with their counterparts in orthopedic and plastic surgery, neurosurgery residents performed significantly fewer cases. Exposure for neurosurgery residents remains unchanged over the study period while plastic surgery residents experienced an increase in case volume. The deficiency in exposure for neurosurgical residents must be addressed to harness interest and proficiency in PNS.

Spine surgery entails a wide spectrum of complicated pathologies. Over the years, numerous assistive tools have been introduced to the modern neurosurgeon's armamentarium including neuronavigation and visualization technologies. In this review, we aimed to summarize the available data on 3D printing applications in spine surgery as well as an assessment of the future implications of 3D printing.We performed a comprehensive review of the literature on 3D printing applications in spine surgery.Over the past decade, 3D printing and additive manufacturing applications, which allow for increased precision and customizability, have gained significant traction, particularly spine surgery. 3D printing applications in spine surgery were initially limited to preoperative visualization, as 3D printing had been primarily used to produce preoperative models of patient-specific deformities or spinal tumors. More recently, 3D printing has been used intraoperatively in the form of 3D customizable implants and personalized screw guides.Despite promising preliminary results, the applications of 3D printing are so recent that the available data regarding these new technologies in spine surgery remains scarce, especially data related to long-term outcomes.

OBJECTIVE Adjacent-segment disease (ASD) requiring operative intervention is a relatively common long-term consequence of lumbar fusion surgery. Although the incidence of ASD requiring reoperation is well described for traditional posterior lumbar approaches (2.5%–3.9% per year), it remains poorly characterized for stand-alone lateral lumbar interbody fusion (LLIF). In this study, the authors report their institutional experience with ASD requiring reoperation after LLIF over an extended follow-up period of 4 years. METHODS Medical records were reviewed for 276 consecutive patients who underwent stand-alone LLIF by a single surgeon for degenerative spinal disorders. Inclusion criteria (single-stage, stand-alone LLIF without posterior supplementation, with no prior lumbar instrumentation, and a minimum of 4 years of follow-up) were met by 182 patients, who were analyzed for operative ASD incidence (per-year rate), demographics, and Oswestry Disability Index (ODI) score. Operative ASD was strictly defined as new-onset pathology following index surgery at directly adjacent levels to the prior construct. Operative, rather than symptomatic or radiographic, ASD was analyzed to provide a consistent and impactful endpoint while avoiding retrospective diagnosis. RESULTS The study cohort of 182 patients had an operative ASD rate of 3.3% (n = 6 procedures) over 4 years of follow-up, for an incidence on Kaplan-Meier survival analysis of 0.88% (95% CI 0.67%–1.09%) per year. In comparing patients with operative ASD with those without, there were no significant differences in mean age (53.7 vs 56.2 years), male sex (33.3% vs 44.9%), smoking status (16.7% vs 25.0%), or number of levels fused (mean 1.33 vs 1.46). The operative ASD cohort had a greater mean BMI (37.3 vs 30.2, p < 0.01). Operative ASD patients had lower baseline ODI scores (33.8 vs 48.3, p = 0.02); however, no difference was observed in ODI at 6 weeks (34.0 vs 39.0) or 3 months (16.0 vs 32.8) postoperatively. CONCLUSIONS The incidence of ASD in LLIF for degenerative lumbar etiologies in this cohort was 0.88% (95% CI 0.67%–1.09%) per year. Meanwhile, the reported reoperation rates for ASD in posterior spinal approaches was 2.5% to 3.9% per year, which implies that LLIF may be preferable for well-selected patients.

BACKGROUND Patients with Thoracolumbar Injury Classification and Severity (TLICS) score of 4 fall into a gray zone between surgical and conservative management. The integrity of posterior ligamentous complex (PLC) evaluated by magnetic resonance imaging (MRI) contributes to surgical decision-making. Load-sharing classification (LSC) may provide a modifier to further guide decision-making in these patients. OBJECTIVE To evaluate associations between LSC score and MRI acquisition, compromise of PLC on MRI, and surgical intervention in TLICS 4 patients. METHODS A cohort of 111 neurologically intact patients with isolated thoracolumbar burst fracture with TLICS 4 was evaluated. LSC score was determined based on degree of comminution (1-3), apposition (1-3), and kyphosis (1-3), total composite score of 3 to 9. RESULTS Overall, 44 patients underwent MRI, 15 had PLC injury, and 32 (28.8%) underwent surgery. LSC score was higher in patients who had an MRI (median 6 vs 3, P

Many investigations exist regarding the effect of the DNA repair enzyme MGMT (O 6 -methylguanine- DNA-methyltransferase)-encoding gene methylation on the antineoplasticity of temozolomide in glioblastoma patients. However, there exist surprisingly lesser studies regarding the associations between MGMT enzyme biochemistry with glial carcinogenesis. MGMT involves in risk of malignancies associated with ionizing radiation, smoking, exposure to polycyclic aromatic hydrocarbons, chlorinated solvents, vinylchloride and hairdyes. All these factors are also proposed to link with gliomagenesis, yet MGMT interactions with these carcinogens in gliomagenesis are not studied yet. In future, MGMT sequencing may be employed in vulnerable populations working in industries associated with exposure to these carcinogens to develop preventive strategies. Given that MGMT is involved in DNA repair, a polymorphism may simultaneously modify the risk of gliomas while enhancing temozolomide cytotoxicity in both marrow and tumor cells.

Meperidine (pethidine) is a µ-opioid receptor (MOR) agonist widely used in the treatment of cancer pain. While MOR agonists in experimental models have demonstrated both pro- and antitumorigenic properties, meperidine has unique features which may be predominantly anticancer in nature. Meperidine both inhibits NMDA (N-methyl-D-Aspartate) receptors, which are involved in the progression of glioblastoma, and blocks NADH:Ubiquinone Oxidoreductase, which may hinder mitochondrial respiration. In the developing embryonic neural tissue, meperidine reduces cell proliferation around the neural tube and lowers the expression of the B RE (brain and reproductive organ-expressed). This is notable given that the B RE gene is implicated in cancer chemoresistance and gliomagenesis. Further, meperidine inhibits P-glycoprotein, which is involved in cancer multidrug resistance and the degradation of the sphingolipid backbone, ceramide. By enhancing the pro-autophagic and pro-apoptotic ceramide levels in cancer cells, meperidine stimulates cell death and reverses multidrug resistance. Tamoxifen, a safe medication employed in the treatment of breast cancer, directly blocks P-glycoprotein and boosts levels of ceramide both via inhibition of glycosylceramide synthase and ceramidase. Further, tamoxifen blocks NMDA-neurotoxicity and therefore it may act synergistically with meperidine in reducing glioblastoma progression associated with NMDA-activation. Finally, tamoxifen blocks glycolysis which may enhance the mitochondrial-blocking activity of meperidine to shut down energy metabolism of glioblastoma cells. Because of these properties, we believe that the combination of meperidine and tamoxifen merits study in cell culture and animal models to investigate a potential synergistic relationship in the treatment of glioblastoma.

Background Opioid use in the management of pain secondary to spinal disorders has grown significantly in the United States. However, preoperative opioid use may complicate recovery in patients undergoing surgical procedures. Objective To test our hypothesis that prolonged preoperative opioid use may lead to poorer patient outcomes following minimally invasive stand-alone lateral lumbar interbody fusion (LLIF) for lumbar degenerative disc disease. Methods A consecutive series of patients from a single institution undergoing LLIF between December 2009 and January 2017 was retrospectively analyzed. Patients were categorized according to the presence or absence of prescribed preoperative opioid use for at least 3 mo. Outcomes included the Oswestry Disability Index (ODI), visual analog scale (VAS), and Short Form 36 Physical and Mental Summary Scores (SF-36 PCS, SF-36 MCS). Results Of 107 patients, 57 (53.1%) were prescribed preoperative opioids. There was no significant difference in preoperative ODI, VAS score, SF-36 PCS, or SF-36 MCS between opioid use groups. Mean postoperative ODI was greater in patients with preoperative opioid use at 41.7 ± 16.9 vs 22.2 ± 16.0 (P = .002). Mean postoperative VAS score was greater in patients prescribed preoperative opioids, while magnitude of decrease in VAS score was greater in opioid-naive patients (P = .001). Postoperative SF-36 PCS was 33.1 ± 10.6 in the opioid use group compared to 43.7 ± 13.1 in the nonuse group (P = .001). Conclusion Following LLIF, patients prescribed preoperative opioids had increased postoperative lumbar pain, disability, and subjective pain.

Interbody fusion is commonly utilized for arthrodesis and stability among patients undergoing spine surgery. Over the last few decades, interbody device materials, such as titanium and polyetheretherketone (PEEK), have been replacing traditional autografts and allografts for interbody fusion. As such, with the exponential growth of bioengineering, a large variety cage surface technologies exist. Different combinations of cage component materials and surface modifications have been created to optimize interbody constructs for surgical use. This review aims to provide a comprehensive overview of common surface technologies, their performance in the clinical setting, and recent modifications and material combinations.We performed a comprehensive review of the literature on titanium and PEEK as medical devices between 1964 and 2021. We searched five major databases, resulting in 4974 records. Articles were screened for inclusion manually by two independent reviewers, resulting in 237 articles included for review.Interbody devices have rapidly evolved over the last few decades. Biomaterial and biomechanical modifications have allowed for continued design optimization. While titanium has a high osseointegrative capacity, it also has a high elastic modulus and is radio-opaque. PEEK, on the other hand, has a lower elastic modulus and is radiolucent, though PEEK has poor osseointegrative capacity. Surface modifications, material development advancements, and hybrid material devices have been utilized in search of an optimal spinal implant which maximizes the advantages and minimizes the disadvantages of each interbody material.

OBJECTIVE Cage subsidence is a well-known phenomenon after lateral lumbar interbody fusion (LLIF), occurring in 10%–20% of cases. A 3D-printed porous titanium (pTi) cage has a stiffness that mimics the modulus of elasticity of native vertebrae, which reduces stress at the bone-hardware interface, lowering the risk of subsidence. In this study, the authors evaluated their institutional rate of subsidence and resultant reoperation in patients who underwent LLIF using a 3D-printed pTi interbody cage. METHODS This is a retrospective case series of consecutive adult patients who underwent LLIF using pTi cages from 2018 to 2020. Demographic and clinical characteristics including age, sex, bone mineral density, smoking status, diabetes, steroid use, number of fusion levels, posterior instrumentation, and graft size were collected. The Marchi subsidence grade was determined at the time of last follow-up. Outcome measures of interest were subsidence and resultant reoperation. Univariable logistic regression analysis was performed to assess the extent to which clinical and operative characteristics were associated with Marchi grade I–III subsidence. Significance was assessed at p < 0.05. RESULTS Fifty-five patients (38 with degenerative disc disease and 17 with adult spinal deformity) were treated with 97 pTi interbody cages with a mean follow-up of 18 months. The mean age was 63.6 ± 10.1 years, 60% of patients were female, and 36% of patients had osteopenia or osteoporosis. Patients most commonly underwent single-level LLIF (58.2%). Sixteen patients (29.1%) had posterior instrumentation. The subsidence grade distribution was as follows: 89 (92%) grade 0, 5 (5%) grade I, 2 (2%) grade II, and 1 (1%) grade III. No patients who were active or prior smokers and no patients with posterior instrumentation experienced graft subsidence. No clinical or operative characteristics were significantly associated with graft subsidence. One patient (1.8%) required reoperation because of subsidence. CONCLUSIONS In this institutional case series, subsidence of pTi intervertebral cages after LLIF occurred in 8% of operated levels, 3% of which were grade II or III. Only 1 patient required reoperation. These reported rates are lower than those reported for polyetheretherketone implants. Further studies are necessary to compare the impact of these cage materials on subsidence after LLIF.

Noscapine is a phthalide isoquinoline alkaloid that easily traverses the blood brain barrier and has been used for years as an antitussive agent with high safety. Despite binding opioid receptors, noscapine lacks significant hypnotic and euphoric effects rendering it safe in terms of addictive potential. In 1954, Hans Lettre first described noscapine as a mitotic poison. The drug was later tested for cancer treatment in the early 1960's, yet no effect was observed likely as a result of its short biological half-life and limited water solubility. Since 1998, it has regained interest thanks to studies from Emory University, which showed its anticancer activity in animal models with negligible toxicity. In contrast to other microtubule-inhibitors, noscapine does not affect the total intracellular tubulin polymer mass. Instead, it forces the microtubules to spend an increased amount of time in a paused state leading to arrest in mitosis and subsequently inducing mitotic slippage/mitotic catastrophe/apoptosis. In experimental models, noscapine does not induce peripheral neuropathy, which is common with other microtubule inhibitors. Noscapine also inhibits tumor growth and enhances cancer chemosensitivity via selective blockage of NF-kappa B, an important transcription factor in glioblastoma pathogenesis. Due to their anticancer activities and high penetration through the blood-brain barrier, noscapine analogues strongly deserve further study in various animal models of glioblastoma as potential candidates for future patient therapy.

Background: Percutaneous balloon kyphoplasty (BK) is widely accepted as both a safe and effective method for the treatment of symptomatic benign vertebral compression fractures (VCFs) of the thoracic and lumbar spines. A disruption in the posterior wall of the affected vertebra is often considered to be a relative or an absolute contraindication to BK. This study was performed to determine the safety as well as the efficacy of BK for vertebral body compression fractures associated with posterior wall disruption. Methods: This was a retrospective, nonrandomized clinical cohort investigation of patients with VCF and posterior wall disruption treated with BK between 2010 and 2018. All cases were performed using a bipedicular technique. Each case was examined for cement leakage, anterior vertebral body height restoration, improvement in pain (determined by VAS) from baseline and 6-week postprocedure, and clinical sequelae from cement leakage. Results: Ninety-eight consecutive patients with 157 VCF levels who underwent BK were evaluated. There was a significant improvement in anterior vertebral height, vertebral wedge angle, and local kyphotic angle in all cases. The mean preoperative VAS improved from 8.7 preprocedure to 2.5 postprocedure (P = .001). There were 14 (9%) cases with asymptomatic cement leakage outside of the vertebral body, and no patients experienced postprocedure neurological symptoms at the 6-week follow up. Conclusions: BK in the setting of posterior wall disruption was found to be a safe and highly effective treatment for patients with benign compression fractures. Posterior wall disruption should not be considered an absolute contraindication to BK.

Background Stereotactic radiosurgery (SRS) is widely accepted as a minimally invasive alternative to surgery in the management of arteriovenous malformations (AVMs). Dilated AVM outflow veins or varices may be caused by high-flow or partial outflow obstruction, which may increase the risk of a hemorrhage before or after SRS. Objective To compare the obliteration and hemorrhage risks in patients with and without AVM varices (AVMv). Methods From our prospective database of 1012 AVM patients who underwent Gamma Knife® (Elekta) SRS, we identified 103 patients with AVMv, and 847 patients without varices. The median follow-up was 52 mo. Balancing variable score matching was performed to compare obliteration and hemorrhage rates between the 2 groups. Results Obliteration rates in the AVMv group were 38% at 3 yr, 65% at 4 yr, and 70% at 5 yr. Patients with an AVMv had no difference in the final obliteration rate compared to patients who did not have variceal drainage (P = .35). Actuarial hemorrhage after SRS in the matched patients with AVMv was 4.9%, 13%, and 13.7%, at 1, 3, and 5 yr, respectively. The rate of hemorrhage in the group with no varix was 2.9%, 5.4%, and 9.1% at 1, 3, and 5 yr, respectively (P = .14). Conclusion The presence of AVM variceal venous drainage did not affect the obliteration rate and did not confer a higher risk of a subsequent hemorrhage both before and after SRS.

OBJECTIVE Patient feedback surveys provide important insight into patient outcomes, satisfaction, and perioperative needs. Recent critiques have questioned provider-initiated surveys and their capacity to accurately gauge patient perspectives due to intrinsic biases created by question framing. In this study, the authors sought to evaluate provider-independent, patient-controlled social media Instagram posts in order to better understand the patient experience following scoliosis correction surgery. METHODS Twitter and Instagram were queried for posts with two tagged indicators, #scoliosissurgery or @scoliosissurgery, resulting in no relevant Twitter posts and 25,000 Instagram posts. Of the initial search, 24,500 Instagram posts that did not directly involve the patient’s own experience were eliminated. Posts were analyzed and coded for the following criteria: the gender of the patient, preoperative or postoperative timing discussed in the post, and classified themes related to the patient’s experiences with scoliosis correction surgery. RESULTS Females made 87.6% of the Instagram posts about their experience following scoliosis correction surgery. The initial postoperative stage of surgery was mentioned in 7.6% of Instagram posts. The most common theme on Instagram involved offering or seeking online support from other patients, which constituted 85.2% of all posts. Other common themes included concern about the surgical scar (31.8%), discussing the results of treatment (28.8%), and relief regarding results (21.2%). CONCLUSIONS Social media provided a platform to analyze unprompted feedback from patients. Patients were most concerned with their scoliosis correction surgery in the period of time 2 weeks or more after surgery. Themes that were most commonly found on Instagram posts were offering or seeking online support from other patients and concern about the surgical scar. Patient-controlled social media platforms, like Instagram, may provide a useful mechanism for healthcare providers to understand the patient experience following scoliosis correction surgery. Such platforms may help in evaluating postoperative satisfaction and improving postoperative quality of care.

Anticoagulation for postoperative venous thromboembolism (VTE) may infer a higher risk of intracranial hemorrhage. We treat patients with VTE using slowly titrating intravenous heparin drip without bolus. When PTT is greater than 60 s, a head CT is obtained to monitor for the development of a intracranial hemorrhage before transition to oral anticoagulation. We evaluated the utility of routine surveillance head CT to monitor for intracranial hemorrhage during anticoagulation. This is a case series of neurosurgical patients in an academic quaternary hospital who developed a VTE after cranial procedures between 2007 and 2017. Over 11,000 patients were screened for the study. Patients’ demographics data, surgical indication, PTT at the time of surveillance CT head, surveillance CT head findings, and patient’s clinical course were reviewed. A total of 83 patients were included. Three patients (3.6%) developed a new subclinical hemorrhage on CT head imaging while on heparin drip. Interval CT head showed stable hemorrhage in all patients. Heparin drip was stopped in two patients and they both progressed from DVT to pulmonary embolism: one patient died due to cardiac arrest, the other patient was transitioned to oral anticoagulation. In the third patient heparin drip was continued uneventfully and transitioned to oral anticoagulation with no further clinical sequalae. Surveillance CT while on heparin drip for VTE management detected subclinical intracranial hemorrhage in a small subset of patients. Patients whose anticoagulation was stopped had progression of VTE. Undertreatment of VTE in the presence of subclinical hemorrhage may lead to significant morbidity and mortality.

Traumatic clival fractures in the pediatric population are associated with high mortality rates. In our previously reported series, a subset of clival fractures were associated with traumatic diastasis of the surrounding clival synchondroses. Herein, we describe a pediatric case of an isolated traumatic diastasis of the clival synchondroses without clival fracture with significant injury to neurovascular structures. To our knowledge this is the first report to describe this entity. Careful radiological attention should be made towards the clival synchondroses in crushing head injuries to best tailor screening for cerebrovascular injury even in the absence of clival fractures.

Background Metal allergies affect a significant portion of the population; intracranial flow diverters contain many of the most commonly allergenic metals. Prior literature has suggested patch testing for all patients with documented or suspected metal allergies before intracranial flow diverter placement; however, there remains a paucity of reports of patients with documented metal allergies undergoing intracranial flow diversion. Case Description We report 2 patients with documented nickel allergies, confirmed via patch testing by a board-certified allergist, and unruptured intracranial aneurysms that underwent treatment with the PED. Both patients developed contact dermatitis when a PED was affixed to their skin during their preoperative workup. Follow-up arteriography at 12 and 36 months post PED placement showed no evidence of in-stent stenosis or intimal hyperplasia, and both patients never developed systemic allergic reactions. Conclusions In 2 patients with known nickel allergies and intracranial aneurysms treated with the PED, there were no clinically or radiographically apparent allergic reactions at greater than 2 years of follow-up.

OBJECTIVE Minimally invasive surgery (MIS) techniques, particularly lateral lumbar interbody fusion (LLIF), have become increasingly popular for adult spinal deformity (ASD) correction. Much discussion has been had regarding theoretical and clinical advantages to addressing coronal curvature from the convex versus concave side of the curve. In this study, the authors aimed to broadly evaluate the clinical outcomes of addressing ASD with circumferential MIS (cMIS) techniques while accessing the lumbar coronal curvature from the concave side. METHODS A multi-institution, retrospective chart and radiographic review was performed for all ASD patients with at least a 10° curvature, as defined by the Scoliosis Research Society, who underwent cMIS correction. The data collected included convex versus concave access to the coronal curve, durable or sensory femoral nerve injury lasting longer than 6 weeks, vascular injury, visceral injury, and any additional major complication, with at least a 2-year follow-up. Neither health-related quality-of-life metrics nor spinopelvic parameters were included within the scope of this study. RESULTS A total of 152 patients with ASD treated with cMIS correction via lateral access were identified and analyzed. Of these, 126 (82.9%) were approached from the concave side and 26 (17.1%) were approached from the convex side. In the concave group, 1 (0.8%) motor and 4 (3.2%) sensory deficit cases remained at 6 weeks after the operation. No vascular, visceral, or catastrophic intraoperative injuries were encountered in the concave group. Of the 26 patients in the convex group, 2 (7.7%) experienced motor deficits lasting longer than 6 weeks and 5 (19.2%) had lower-extremity sensory deficits. CONCLUSIONS It has been reported that lateral access to the convex side is associated with similar clinical and radiographic outcomes with fewer complications when compared with access to the concave side. Advantages to approaching the lumbar spine from the concave side include using one incision to access multiple levels, breaking the operative table to assist with curvature correction, easier access to the L4–5 disc space, the ability to release the contracted side, and, often, avoidance of the need to access or traverse the thoracic cavity. This study illustrates the largest reported cohort of concave access for cMIS scoliosis correction; few postoperative sensory and motor deficits were found.

OBJECTIVEStand-alone lateral lumbar interbody fusion (LLIF) is a useful minimally invasive approach for select spinal disorders, but implant subsidence may occur in up to 30% of patients. Previous studies have suggested that wider implants reduce the subsidence rate. This study aimed to evaluate whether a mismatch of the endplate and implant area can predict the rate and grade of implant subsidence.METHODSThe authors conducted a retrospective review of prospectively collected data on consecutive patients who underwent stand-alone LLIF between July 2008 and June 2015; 297 patients (623 surgical levels) met inclusion criteria. Imaging studies were examined to grade graft subsidence according to Marchi criteria. Thirty patients had radiographic evidence of implant subsidence. The endplates above and below the implant were measured.RESULTSA total of 30 patients with implant subsidence were identified. Of these patients, 6 had Marchi grade 0, 4 had grade I, 12 had grade II, and 8 had grade III implant subsidence. There was no statistically significant correlation between the endplate-implant area mismatch and subsidence grade or incidence. There was also no correlation between endplate-implant width and length mismatch and subsidence grade or incidence. However, there was a strong correlation between the usage of the 18-mm-wide implants and the development of higher-grade subsidence (p = 0.002) necessitating surgery. There was no significant association between the degree of mismatch or Marchi subsidence grade and the presence of postoperative radiculopathy. Of the 8 patients with 18-mm implants demonstrating radiographic subsidence, 5 (62.5%) required reoperation. Of the 22 patients with 22-mm implants demonstrating radiographic subsidence, 13 (59.1%) required reoperation.CONCLUSIONSThere was no correlation between endplate-implant area, width, or length mismatch and Marchi subsidence grade for stand-alone LLIF. There was also no correlation between either endplate-implant mismatch or Marchi subsidence grade and postoperative radiculopathy. The data do suggest that the use of 18-mm-wide implants in stand-alone LLIF may increase the risk of developing high-grade subsidence necessitating reoperation compared to the use of 22-mm-wide implants.

Increasing recent evidence suggests a key role of oligodendroglial injury and demyelination in the pathophysiology of Huntington's Disease (HD) and the transcription factor PPAR delta is critical for oligodendroglial regeneration and myelination. PPAR delta directly involves in the pathogenesis of HD and treatment with a brain-permeable PPAR delta-agonist (KD3010) alleviates its severity in mice. Erucic acid (EA) is also a PPAR delta-ligand omega 9 fatty acid which is highly consumed in Asian countries through ingesting cruciferous vegetables such as rapeseed (Brassica napus) and indian mustard (Brassica juncea). EA is also an ingredient of Lorenzo's oil employed in the medical treatment of adrenoleukodystrophy and can be converted to nervonic acid, a component of myelin. HD pathogenesis also involves oxidative and inflammatory injury and EA exerts antioxidative and antiinflammatory efficacies including inhibition of thrombin and elastase. Consumption of rapeseed, indian mustard, and Canola oils (containing EA) improves cognitive parameters in animal models, as well as treatment with pure EA. Moreover, erucamide, an endogenous EA-amide derivative regulating angiogenesis and water balance, exerts antidepressive and anxiolytic effects in mice. Hitherto, no study has investigated the therapeutic potential of EA in HD and we believe that it strongly merits to be studied in animal models of HD as a potential therapeutic.

In this review study, we focus on potential benefits of the transcription factor PPARδ and its ligand erucic acid (EA) in management of neuroectodermal tumors and Parkinson's Disease. PPARδ is a nuclear receptor and transcription factor that induces myelination, promotes oligodendroglial and neuronal differentiation, and possess anti-neuroinflammatory properties. While both pro-tumorigenic and anti-tumorigenic effects have been described for PPARδ, we propose that PPARδ may perform a predominantly anticancer role in tumors originating from the neuroectoderm. PPARδ ligand-activation via oleic acid and GW501516, or overexpression of PPARδ, elicits profound antitumor actions in neuroblastoma and melanoma. In glioblastomas, there is evidence indicating a differentiation failure of O2A (oligodendroglial-astrocytic biprogenitor) cells and it has been shown that EA reduced DNA synthesis in C6 rat glioblastoma spheroid cultures in clinically achievable concentrations. EA is a ω9 fatty acid which is being used in the treatment of adrenoleukodystrophy. EA is widely consumed in Asian countries via ingestion of cruciferous vegetables including mustard and rapeseed oil. EA also exerts antioxidant and anti-inflammatory activities. Recent studies of Parkinson's Disease (PD) have implicated demyelination, white matter pathology, oligodendroglial injury, and neural inflammation in the underlying pathophysiology. In the rotenone PD model in rats, PPARδ ligand GW501516 saves dopaminergic neurons during injury induced by chemical toxins and improves behavioral functioning in PD via alleviation of endoplasmic reticulum stress. PPARδ agonists also reduce the NLRP3 inflammasome-associated neural inflammation in the MPTP PD model in mice. Herein, we propose that PPARδ and its ligand EA highly deserve to be studied in animal models of neuroblastoma, glioblastoma, and PD.

Background Dural thickening is observed in lymphoma, dural carcinomatosis, meningioma, tuberculosis, and autoimmune diseases. We encountered a patient with dural thickening and complaints of neck and back pain, numbness and loss of strength in the hands. The patient also suffered from polychondritis and had previously received steroid and methotrexate treatment for this indication. The patients’ serum was also positive for ANA, yet she did not have any other findings suggesting lupus. Our radiological and pathological analysis revealed IHSP (IgG4-related hypertrophic sclerosing pachymeningitis). In this review study, we provided a detailed literature survey to increase the awareness about IHSP in the neurosurgical community. Methods MRI (magnetic resonance imaging)-based radiological analyses revealed a posterior extramedullary spinal mass extending from C2 to T2-T3 level. The dural mass was surgically excised and a broad panel of immunohistochemical markers including S100, EMA, CD246/ALK-1, CD45, CD20, CD79a, CD138, CD68, CD1a and CD34 was studied. Immunoglobulin heavy chain/kappa chain gene rearrangement analysis was performed which ruled out a lymphoproliferative disorder. Results MRI and pathological findings suggested IHSP. As the disease relapsed with a new anterior extramedullary multilobulated lesion extending from C5 to T1 level, the patient is now closely monitored for further medical and surgical treatment. Conclusions IHSP is a relatively novel entity of hypertrophic pachymeningitis and should be included in the differential diagnosis of dural thickening. The fibrosis accompanying IHSP may not respond to medical treatment, which includes steroids and immunosuppressive agents. Additionally, neurological deficits, seizures, spinal decompression, hydrocephalus, or brainstem compression necessitate early surgical intervention. A continued vigilance is also necessary as the disease may relapse long-term following surgical treatment.

The authors report a complex case of an 18-year-old male with a history of hydrocephalus secondary to intraventricular hemorrhage of prematurity, with more than 30 previous shunt revisions, who presented to the authors' institution with shunt malfunction. After exhausting his peritoneal cavity and pleural space as possible distal sites of shunt placement, he underwent a direct heart shunt placement when it was discovered he had thrombosis of his subclavian vein precluding a standard wire-guided atrial cannulation. His course was complicated by postoperative distal catheter migration and repeat surgery for reimplantation of the shunt directly into the atrium. At the 16-month follow-up visit, the patient showed no symptoms of shunt malfunction or pericardial effusion. Imaging studies demonstrated a functioning shunt system. This is the second reported successful ventricle to direct heart shunt placement in an adult. The authors report on the technical aspects of the case and review the relevant literature.

Surgical revascularization for adults with moyamoya disease (MD) includes direct, indirect, or combination bypasses. It is unclear which provides the best outcomes. We sought to determine the best surgical management for adults with MD by comparing perioperative complications and long-term outcomes among 3 bypass types.Literature databases were searched for articles reporting revascularization bypass outcomes for adults with MD. A pooled analysis of all qualified studies and meta-analysis using only studies reporting direct comparisons of 2 bypass types were performed. Overall odds ratios (ORs) comparing 2 bypass types were computed and publication bias was assessed. Rates of perioperative and long-term hemorrhage and ischemia and favorable outcomes were compared.Forty-seven studies were analyzed; 8 had level 1 or 2 evidence. Pooled analyses showed that perioperative hemorrhage rates were significantly (P = 0.02) lower with indirect compared with direct (OR, 0.03; 95% confidence interval [CI], 0.002-0.55) or combined (OR, 0.03; 95% CI, 0.002-0.53) bypasses. Meta-analysis showed that direct bypass was better at preventing long-term hemorrhage than was indirect bypass (OR, 0.26; 95% CI, 0.09-0.79; P = 0.02). Pooled analyses showed that direct is significantly better (P0.01) than indirect (OR, 0.51; 95% CI, 0.33-0.77) and combined (OR, 0.47; 95% CI, 0.31-0.72) bypasses in preventing long-term ischemia. Meta-analysis showed that direct was better than indirect bypass in producing long-term favorable outcomes (OR, 2.62; 95% CI, 1.19-5.79; P = 0.02), and the pooled analysis showed that combined bypass was better than indirect bypass in producing long-term favorable outcomes (OR, 1.26; 95% CI, 1.03-1.54; P = 0.02).Overall, our analyses suggest that direct bypass with or without indirect augmentation provides the best outcomes for adults with MD.

OBJECT Lesioning of the dorsal root entry zone (DREZotomy) is an effective treatment for brachial plexus avulsion (BPA) pain. The role of preoperative assessment with MRI has been shown to be unreliable for determining affected levels; however, it may have a role in predicting pain outcomes. Here, DREZotomy outcomes are reviewed and preoperative MRI is examined as a possible prognostic factor. METHODS A retrospective review was performed of an institutional database of patients who had undergone brachial plexus DREZ procedures since 1995. Preoperative MRI was examined to assess damage to the DREZ or dorsal horn, as evidenced by avulsion of the DREZ or T2 hyperintensity within the spinal cord. Phone interviews were conducted to assess the long-term pain outcomes. RESULTS Between 1995 and 2012, 27 patients were found to have undergone cervical DREZ procedures for BPA. Of these, 15 had preoperative MR images of the cervical spine available for review. The outcomes were graded from 1 to 4 as poor (no significant relief), good (more than 50% pain relief), excellent (more than 75% pain relief), or pain free, respectively. Overall, DREZotomy was found to be a safe, efficacious, and durable procedure for relief of pain due to BPA. The initial success rate was 73%, which declined to 66% at a median follow-up time of 62.5 months. Damage to the DREZ or dorsal horn was significantly correlated with poorer outcomes (p = 0.02). The average outcomes in patients without MRI evidence of DREZ or dorsal horn damage was significantly higher than in patients with such damage (3.67 vs 1.75, t-test; p = 0.001). A longer duration of pain prior to operation was also a significant predictor of treatment success (p = 0.004). CONCLUSIONS Overall, the DREZotomy procedure has a 66% chance of achieving meaningful pain relief on long-term follow-up. Successful pain relief is associated with the lack of damage to the DREZ and dorsal horn on preoperative MRI.

Objective Anterior cervical spine decompression and fusion are common neurosurgical operations. Reoperation of the anterior cervical spine is associated with increased morbidity. The authors describe a novel subcricoid approach to protect the recurrent laryngeal nerve in a cuff of tissue while facilitating surgical access to the anterior cervical spine. Methods Single institution, consecutive case review of 48 patients undergoing reoperation in the anterior cervical region including the level of C5 and below. Univariable and multivariable regression analysis was used to determine predictors of postoperative morbidity. Results No intraoperative complications were reported. Estimated blood loss for the approach was 13.6 ± 3.1 mL. Nine of 48 patients developed immediate postoperative complications, including vocal cord paresis (10.4%), moderate-to-severe dysphagia (10.4%), and neck edema requiring intubation (2.1%). No postoperative hematomas or death occurred. All complications occurred with 4 or more levels of exposure (1–3 disc levels, 0%, vs. ≥4 disc levels, 31%). Extension of the exposure to the upper thoracic spine was associated with odds for postoperative complications (adjusted odds ratio, 6.50; 95% confidence interval, 1.14–37.03) and prolonged hospital stay (adjusted increase 4.23 days, P Conclusion The tunneled subcricoid approach is a relatively safe corridor to reapproach the anterior cervical spine at the level of C5 and below. However, caution must be exercised when using this approach to expose 4 or more disc levels and with extension of the exposure to the upper thoracic spine. Future comparative studies are needed to establish patient selection criteria in determining the use of this technique compared with classic approaches.

A failure of neurodevelopmental differentiation at the level of oligodendroglial-astrocytic biprogenitors (O2A) is shown to be involved in the pathogenesis of both multiple sclerosis (MS) and glioblastoma multiforme (GBM). In this review article, we suggest that certain antigens of Hepatitis B Virus (HBV) and HBV-Vaccine (HBV-V) could act as immune stimulants in GBM treatment based on several lines of evidence. HBV-Vs may cause rare but prominent neuroimmune side effects including demyelination and multiple sclerosis, which may be associated with HBV-proteins creating antigenic mimicry of oligodendroglial progenitors. The combined prevalance of HBV and Hepatitis C Virus-carrier state is less in patients with brain tumors compared to healthy subjects. Furthermore, within the population of patients with brain tumors, the prevalence is even about two times lesser in GBM in comparison to those with a diagnosis of meningioma. Although indirectly, this epidemiological data may indicate that the immune response triggered against hepadnavirus antigens would eliminate aberrantly differentiating O2A progenitor cells giving rise to GBMs. Moreover, Hepatitis B surface antigen-antibody variable domain is among the top 100 differentially expressed transcripts in fresh frozen and formalin-fixed paraffin-embeded specimens obtained from pediatric GBM tissues in comparison to the control brain tissues. However, the provided evidence is still premature and we think that HBV-V warrants investigation first by epidemiological studies and then by animal experiments to determine whether it reduces the risk of GBM and whether it could slow GBM growth via immune stimulation.

Background The overall survival rates for breast cancer are increasing due to controlled brain disease and improved systemic treatments. This study examined neurologic outcomes, tumor control, and survival data in breast cancer patients with multiple brain metastases and who required salvage stereotactic radiosurgery (SRS) for recurrent breast cancer brain metastases. Methods The study included 231 patients with a primary diagnosis of breast cancer who underwent SRS for more than 1 brain metastases from May 1993 and July 2007. Survival analyses via univariate and multivariate Cox regression demonstrated interactions between survival and predictor values including Karnofsky Performance Scale, Recursive Partitioning Analysis Class, number of brain metastases, whole-brain radiotherapy (WBRT), immunotherapy, and chemotherapy. Results Of the 231 patients, the survival rate was 53% at 1 year and 26% at 5 years from initial SRS. Controlled systemic disease, adjuvant chemotherapy, and Recursive Partitioning Analysis class II were significant predictors of increased survival, while WBRT was a significant predictor of decreased survival. The median survival in patients who received WBRT after SRS was 11 months versus 23 months in those who did not. The local tumor control rate at initial follow-up was 95%. Of these, 40% of patients underwent additional brain SRS. Following salvage SRS, 8% of patients developed symptomatic adverse radiation events; however, the development of symptomatic adverse radiation events had no effect on patient survival. Conclusions This report indicated that both initial and salvage SRS procedures in breast cancer patients with multiple brain metastases are effective for local control of intracranial disease while minimizing adverse radiation effects.

In this review article, we hypothesize that Hepatitis B Virus Vaccine (HBV-V) and certain antigens of Hepatitis B Virus (HBV) could act as anticancer immunoadjuvants in addition to their role of preventing HBV-associated liver cancer. Evidence suggests that in animal breast cancer and melanoma models, combining hepatitis B-surface antigen (HBsAg) with other cancer antigens resulted in enhanced antitumour activity. HBsAg shares antigenic mimicry with healthy and malignant cells including squamous epithelia, thymic epithelia, bladder- and colon cancer cells. There exist anecdotal reports and small case series about spontaneous remission of leukaemias and neuroblastoma following acute HBV-infection. Recent studies also exist showing HBV-carrier state is a good prognostic factor for intrahepatic cholangiocarcinoma. Further epidemiological studies and animal experiments are necessary whether HBV-Vs exert additional immunoadjuvant benefits besides lowering the risk of liver cancer.

Background and purposeAccess-site complications constitute a substantial portion of the morbidity associated with transfemoral cerebral angiography, yet no standardized protocol exists for femoral closure and practice patterns vary widely. The objective of this single-arm prospective cohort study was to validate the efficacy and safety of a standardized femoral closure strategy for all diagnostic angiography, regardless of antiplatelet regimen.MethodsA single-arm, prospective study was designed enrolling consecutive patients undergoing diagnostic transfemoral cerebral angiography by a single neurointerventional surgeon from March 2013 – March 2018. The closure protocol consisted of 20 minutes of manual compression to the site of arterial access and 2 hours of bedrest. The primary outcome was hematoma or oozing after manual compression. Demographic, clinic, and laboratory data were collected and analyzed, and patients were stratified by antiplatelet use.ResultsOf 525 angiograms, 263 (50.1%) were on patients taking antiplatelet medication, with 66 (12.6%) on dual antiplatelet regimens. Five patients (0.95% of all patients) met the primary outcome: in all five cases, there was no further oozing or enlarging hematoma after the additional compression period. There were not significant differences in primary outcome in groups stratified by antiplatelet use, and there were no instances of delayed hematoma, pseudoaneurysm, or arteriovenous fistula.ConclusionIn this single-arm cohort study of 525 consecutive transfemoral angiograms with a standardized extrinsic compression protocol, hemostasis was achieved without complication in >99% regardless of antiplatelet strategy. This protocol is effective and safe for diagnostic transfemoral angiography regardless of a patient’s antiplatelet use.

Methenamine (hexamethylenetetramine, hexamine, urotropine) is a compound discovered in 1859, which is still currently being used as a urinary antiseptic. Methenamine is highly soluble in water and polar solvents, and its molecular constitution is similar to adamantane compounds with tetrahedral cage like structure. In acidic conditions, methenamine decomposes to formaldehyde and ammonia. Recently, methenamine has gained a renewal of interest due to antibiotic-resistant bacteria urinary tract infections; interestingly, bacteria cannot gain resistance to formaldehyde. In 1968, David and Burkitt reported remarkable regression of four Burkitt Lymphoma patients in eight subjects who were treated with septicemine (a solution containing 6.3 g of methenamine iodomethylate and 1 g of methenamine sodium benzoate in 100 cc distilled water). Unfortunately, these striking observations did not gain interest in the medical community; despite experimental models that showed that methenamine synergized with hyperthermia, radiation, and chemotherapy to block cancer growth. As the hypoxic core of tumours have an acidic pH, it would be plausible to expect that methenamine would selectively target dormant, non-proliferative, and treatment-resistant cancer clones in large tumours. Moreover, previous data suggests that methenamine can be safely used intravenously and for treatment of infections of the central nervous system. It may therefore be an effective adjuvant in treatment of systemic cancers and glioblastoma.

Here we review tumoricidal efficacy of Vitamin D analogues in glioblastoma multiforme (GBM) and potential synergisms with retinoic acid and temozolomide based on epidemiological and cellular studies. Epidemiological data suggest that winter birth is associated with higher risk of GBM, and GBM debulking in the winter enhanced mortality, which may relate with lower exposure to sunlight essential to convert cholecalciferol to Vitamin D. Comparative studies on blood bank specimens revealed that higher prediagnosis levels of calcidiol are associated with lower risk of GBM in elderly men. Supplemental Vitamin D reduced mortality in GBM patients in comparison to nonusers. Expression of Vitamin D Receptor is associated with a good prognosis in GBM. Conversely, Vitamin D increases glial tumor synthesis of neutrophins NGF and NT-3, the low affinity neurotrophin receptor p75NTR, IL-6 and VEGF, which may enhance glioma growth. Antitumor synergisms between temozolomide and Vitamin D and Vitamin D with Vitamin A derivatives were observed. Hence, we hypothesize that Calcitriol + ATRA (All-Trans Retinoic Acid) + Temozolomide – CAT combination might be a safer approach to benefit from Vitamin D in the management of high-grade glial tumors. Adding acetazolomide to this protocol may reduce the risk of pseudotumor cerebri, as both Vitamin D and Vitamin A excess may cause intracranial hypertension; this approach may provide further benefit as acetazolomide also exhibits anticancer activity.

Objective: Trigeminal neuralgia (TN) related to a brainstem cavernous malformation (CM) is a rare entity. We present the first radiosurgical management of a patient with TN secondary to a CM. Clinical Presentation: An 80-year-old female presented with a 33-year history of progressively severe TN refractory to medications. Imaging confirmed a solitary CM located at the pontine dorsal root entry zone of cranial nerve 5. Treatment: Stereotactic radiosurgery of the trigeminal nerve was performed using the Leksell gamma knife. A single 4-mm isocenter of radiation was focused on the trigeminal nerve and a maximum dose of 80 Gy (40 Gy at the 50% isodose line) was delivered to the nerve. Results: At 1 year, the patient noted that the severe pain attacks had been reduced by 75%, although a background lingering discomfort persisted. Pain suppression medications had been significantly reduced to lamotrigine 100 mg twice daily. Her preoperative distribution of sensory dysfunction mildly increased. Conclusion: For medically refractory TN related to a CM, radiosurgery of the afferent nerve may ameliorate pain without a major decrease in sensation. The more than 30-year history of pain in our patient may have reduced the chance of more significant pain relief.

Background and purpose: In sedated pediatric brains, 2D-FLAIR causes increased signal intensity of the cerebrospinal fluid (CSF) leading to false-positive diagnoses. Our aim is to determine whether increased CSF signal intensity is observed on 3D-FLAIR images. Methods: In this institutional review board-approved study, a 2-year retrospective analysis of our MRI database was conducted which revealed 48 sedated pediatric patients with normal cranial MRI findings and 3D-FLAIR sequence. One adult volunteer was imaged before and after O2 inhalation with 2D and 3D-FLAIR sequences. The hyperintensity in the subarachnoid spaces and basal cisterns were quantified as follows: 0: artifact free; 1: homogeneous minimal CSF signal; 2: abnormal CSF signal. Inter-observer agreement was assessed with kappa agreement analysis. Results: Grade 0 and grade 1 signals were observed at inferior to Liliequist membrane (LLQ) in 48/48 and 0/48 cases; prepontine cistern 47/48 and 1/48; superior to LLQ 26/48 and 22/48; 4th ventricle 16/48 and 32/48; 3rd ventricle 34/48 and 14/48; lateral ventricle 3/48 and 45/48; subarachnoid space 36/48 and 12/48, respectively. No patients showed grade 2 signal. Inter-observer agreement was 0.81–1. In the volunteer, after O2 inhalation, grade 2 signal intensity was evident on 2D-FLAIR however; 3D-FLAIR did not show any signal increase. Conclusions: In sedated pediatric brains, 3D-FLAIR suppresses CSF signal, and enables reliable assessment free from CSF artifacts.

OBJECT Trigeminal neuralgia (TN) occurs and recurs in the absence of neurovascular compression (NVC). While microvascular decompression (MVD) is the most effective treatment for TN, it is not possible when NVC is not present. Therefore, the authors sought to evaluate the safety, efficacy, and durability of internal neurolysis (IN), or “nerve combing,” as a treatment for TN without NVC. METHODS This was a retrospective review of all cases of Type 1 TN involving all patients 18 years of age or older who underwent evaluation (and surgery when appropriate) at Oregon Health & Science University between July 2006 and February 2013. Chart reviews and telephone interviews were conducted to assess patient outcomes. Pain intensity was evaluated with the Barrow Neurological Institute (BNI) Pain Intensity scale, and the Brief Pain Inventory–Facial (BPI-Facial) was used to assess general and face-specific activity. Pain-free survival and durability of successful pain relief (BNI pain scores of 1 or 2) were statistically evaluated with Kaplan-Meier analysis. Prognostic factors were identified and analyzed using Cox proportional hazards regression. RESULTS A total of 177 patients with Type 1 TN were identified. A subgroup of 27 was found to have no NVC on high-resolution MRI/MR angiography or at surgery. These patients were significantly younger than patients with classic Type 1 TN. Long-term follow-up was available for 26 of 27 patients, and 23 responded to the telephone survey. The median follow-up duration was 43.4 months. Immediate postoperative results were comparable to MVD, with 85% of patients pain free and 96% of patients with successful pain relief. At 1 year and 5 years, the rate of pain-free survival was 58% and 47%, respectively. Successful pain relief at those intervals was maintained in 77% and 72% of patients. Almost all patients experienced some degree of numbness or hypesthesia (96%), but in patients with successful pain relief, this numbness did not significantly impact their quality of life. There was 1 patient with a CSF leak and 1 patient with anesthesia dolorosa. Previous treatment for TN was identified as a poor prognostic factor for successful outcome. CONCLUSIONS This is the first report of IN with meaningful outcomes data. This study demonstrated that IN is a safe, effective, and durable treatment for TN in the absence of NVC. Pain-free outcomes with IN appeared to be more durable than radiofrequency gangliolysis, and IN appears to be more effective than stereotactic radiosurgery, 2 alternatives to posterior fossa exploration in cases of TN without NVC. Given the younger age distribution of patients in this group, consideration should be given to performing IN as an initial treatment. Accrual of further outcomes data is warranted.

For a variety of neurosurgical conditions, increasing surgeon and hospital volumes correlate with improved outcomes, such as mortality, complication rates, length of stay, hospital charges, and discharge disposition. Neurosurgeons can improve patient outcomes at the population level by changing practice and referral patterns to regionalize care for select conditions at high-volume specialty treatment centers. Individual practitioners should be aware of where they fall on the volume spectrum and understand the implications of their practice and referral habits on their patients.

Objective To analyze whether cavernous sinus sampling (CSS) and dynamic magnetic resonance imaging (dMRI) are consistent with intraoperative findings in Cushing disease (CD) patients. Design Retrospective outcomes study. Setting Oregon Health & Science University; 2006 and 2013. Participants A total of 37 CD patients with preoperative dMRI and CSS to confirm central adrenocorticotropic hormone (ACTH) hypersecretion. Patients were 78% female; mean age was 41 years (at diagnosis), and all had a minimum of 6 months of follow-up. Main Outcome Measures Correlations among patient characteristics, dMRI measurements, CSS results, and intraoperative findings. Results All CSS indicated presence of CD. Eight of 37 patients had no identifiable tumor on dMRI. Three of 37 patients had no tumor at surgery. dMRI tumor size was inversely correlated with age (rs = − 0.4; p = 0.01) and directly correlated to intraoperative lateralization (rs = 0.3; p

Spinal arteriovenous malformations (sAVM) are rare vascular pathologies whose natural history remains incompletely understood. Advances in diagnostic imaging, coupled with the evolution of endovascular and microsurgical techniques have led to the description of a number of classification schemes for these lesions. An updated method has changed AVM classification from five categories of lesion based on source and location of feeder vessels to three categories based on pathophysiology. These categories include extradural arteriovenous fistulae (AVFs), intradural AVFs, extradural-intradural AVFs, intramedullary AVMs, and conus medullaris AVM each with individual subclassifications. Treatment outcomes have been shown to differ based on classification criteria. The increased use of advanced imaging prior to surgical intervention has facilitated the treatment of AVFs. Definitive diagnosis and characterization have traditionally required digital subtraction angiography, which is now being supplemented with other forms of noninvasive imaging such as computed tomography angiography (CTA) and magnetic resonance angiography (MRA). Epidemiologically, intradural dorsal AVFs account for 80% of all sAVMs, and are characterized by low-pressure shunts located in the sleeve of the dorsal nerve root. Microsurgical treatment has been shown to be highly effective in cases of intradural dorsal AVFs, although many cases are also amenable to durable occlusion using liquid embolics. Conus medullaris AVMs, which has only been recently characterized as a separate category of sAVM, is best treated using a combination of embolization and microsurgery. Successful treatment of sAVM mandates a thorough understanding of the anatomy and classification of these lesions. The purpose of this chapter is to review and summarize the classification, natural history, and prognosis of sAVMs.

Arteriovenous malformations (AVMs) are vascular deformities involving fistula formation of arterial to venous structures without an intervening capillary bed. Such anomalies can prove fatal as the high arterial flow can disrupt the integrity of venous walls, thus leading to dangerous sequelae such as hemorrhage. Diagnosis of these lesions in the central nervous system can often prove challenging as intracranial AVMs represent a heterogeneous vascular pathology with various presentations and symptomatology. The literature suggests that most brain AVMs (bAVMs) are identified following evaluation of the etiology of acute cerebral hemorrhage, or incidentally on imaging associated with seizure or headache workup. Given the low incidence of this disease, most of the data accrued on this pathology comes from single-center experiences. This chapter aims to distill the most important information from these studies as well as examine meta-analyses on bAVMs in order to provide a comprehensive introduction into the natural history, classification, genetic underpinnings of disease, and proposed pathophysiology. While there is yet much to be elucidated about AVMs of the central nervous system, we aim to provide an overview of bAVM etiology, classification, genetics, and pathophysiology inherent to the disease process.

Arteriovenous malformations (AVMs) are vascular deformities involving fistula formation of arterial to venous structures without an intervening capillary bed. Such anomalies can prove fatal as the high arterial flow can disrupt the integrity of venous walls, thus leading to dangerous sequelae such as hemorrhage. Diagnosis of these lesions in the central nervous system can often prove challenging as intracranial AVMs represent a heterogeneous vascular pathology with various presentations and symptomatology. The literature suggests that most brain AVMs (bAVMs) are identified following evaluation of the etiology of acute cerebral hemorrhage, or incidentally on imaging associated with seizure or headache workup. Given the low incidence of this disease, most of the data accrued on this pathology comes from single-center experiences. This chapter aims to distill the most important information from these studies as well as examine meta-analyses on bAVMs in order to provide a comprehensive introduction into the natural history, classification, genetic underpinnings of disease, and proposed pathophysiology. While there is yet much to be elucidated about AVMs of the central nervous system, we aim to provide an overview of bAVM etiology, classification, genetics, and pathophysiology inherent to the disease process.

Spinal arteriovenous malformations (sAVM) are rare vascular pathologies whose natural history remains incompletely understood. Advances in diagnostic imaging, coupled with the evolution of endovascular and microsurgical techniques have led to the description of a number of classification schemes for these lesions. An updated method has changed AVM classification from five categories of lesion based on source and location of feeder vessels to three categories based on pathophysiology. These categories include extradural arteriovenous fistulae (AVFs), intradural AVFs, extradural-intradural AVFs, intramedullary AVMs, and conus medullaris AVM each with individual subclassifications. Treatment outcomes have been shown to differ based on classification criteria. The increased use of advanced imaging prior to surgical intervention has facilitated the treatment of AVFs. Definitive diagnosis and characterization have traditionally required digital subtraction angiography, which is now being supplemented with other forms of noninvasive imaging such as computed tomography angiography (CTA) and magnetic resonance angiography (MRA). Epidemiologically, intradural dorsal AVFs account for 80% of all sAVMs, and are characterized by low-pressure shunts located in the sleeve of the dorsal nerve root. Microsurgical treatment has been shown to be highly effective in cases of intradural dorsal AVFs, although many cases are also amenable to durable occlusion using liquid embolics. Conus medullaris AVMs, which has only been recently characterized as a separate category of sAVM, is best treated using a combination of embolization and microsurgery. Successful treatment of sAVM mandates a thorough understanding of the anatomy and classification of these lesions. The purpose of this chapter is to review and summarize the classification, natural history, and prognosis of sAVMs.

Background Somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) are frequently used to monitor neurologic function during spinal deformity surgery. The sensitivity and specificity of intraoperative neurophysiologic monitoring (IONM) in patients undergoing posterior spinal fusion (PSF) is debatable. Methods A retrospective review of all patients undergoing PSF with IONM from October 2008 to December 2012 was performed. Factors including sex, operative time, and spinal levels of posterior fusion were analyzed as risk factors for intraoperative alerts. Results A total of 784 consecutive patients who underwent PSF with IONM without any baseline deficits were analyzed. Patients included 45% men (n = 356) and 55% women (n = 428), with a mean age of 56 years. The mean procedure time was 7 hours. Intraoperative alerts were noted for 3.3% (n = 26) of patients. In this cohort, the average number of levels involved per procedure was approximately 7, ranging from 1 to 16 levels. Of all the spinal levels, the cervicothoracic region had the highest incidence of intraoperative alerts (6 of 97 cervicothoracic cases, P = 0.06). Among these patients, age ( P = 0.32), sex ( P = 0.66), and procedure time ( P = 0.63) were not predictive factors. Four out of 26 (15%) patients had neurologic deficits despite surgeon intervention after neuromonitoring alerts. Conclusions SSEP and MEP changes occurred in 3.3% of patients undergoing PSF, with the highest incidence at the cervicothoracic level. Twenty-three out of 26 patients with intraoperative neuromonitoring changes had improvements in IONM signals after interventions during surgery. Further studies using larger patient numbers may be useful in establishing the utility of neuromonitoring in PSF.