Association of MGMT Promoter Methylation With Survival in Low-grade and Anaplastic Gliomas After Alkylating Chemotherapy

Importance

O6-methylguanine-DNA methyltransferase (MGMT [OMIM 156569]) promoter methylation (mMGMT) is predictive of response to alkylating chemotherapy for glioblastomas and is routinely used to guide treatment decisions. However, the utility of MGMT promoter status for low-grade and anaplastic gliomas remains unclear due to molecular heterogeneity and the lack of sufficiently large data sets.

Objective

To evaluate the association of mMGMT for low-grade and anaplastic gliomas with chemotherapy response.

Design, Setting, and Participants

This cohort study aggregated grade II and III primary glioma data from 3 prospective cohort studies with patient data collected from August 13, 1995, to August 3, 2022, comprising 411 patients: MSK-IMPACT, EORTC (European Organization of Research and Treatment of Cancer) 26951, and Columbia University. Statistical analysis was performed from April 2022 to January 2023.

Exposure

MGMT promoter methylation status.

Main Outcomes and Measures

Multivariable Cox proportional hazards regression modeling was used to assess the association of mMGMT status with progression-free survival (PFS) and overall survival (OS) after adjusting for age, sex, molecular class, grade, chemotherapy, and radiotherapy. Subgroups were stratified by treatment status and World Health Organization 2016 molecular classification.

Results

A total of 411 patients (mean [SD] age, 44.1 [14.5] years; 283 men [58%]) met the inclusion criteria, 288 of whom received alkylating chemotherapy. MGMT promoter methylation was observed in 42% of isocitrate dehydrogenase (IDH)-wild-type gliomas (56 of 135), 53% of IDH-mutant and non-codeleted gliomas (79 of 149), and 74% of IDH-mutant and 1p/19q-codeleted gliomas (94 of 127). Among patients who received chemotherapy, mMGMT was associated with improved PFS (median, 68 months [95% CI, 54-132 months] vs 30 months [95% CI, 15-54 months]; log-rank P < .001; adjusted hazard ratio [aHR] for unmethylated MGMT, 1.95 [95% CI, 1.39-2.75]; P < .001) and OS (median, 137 months [95% CI, 104 months to not reached] vs 61 months [95% CI, 47-97 months]; log-rank P < .001; aHR, 1.65 [95% CI, 1.11-2.46]; P = .01). After adjusting for clinical factors, MGMT promoter status was associated with chemotherapy response in IDH-wild-type gliomas (aHR for PFS, 2.15 [95% CI, 1.26-3.66]; P = .005; aHR for OS, 1.69 [95% CI, 0.98-2.91]; P = .06) and IDH-mutant and codeleted gliomas (aHR for PFS, 2.99 [95% CI, 1.44-6.21]; P = .003; aHR for OS, 4.21 [95% CI, 1.25-14.2]; P = .02), but not IDH-mutant and non-codeleted gliomas (aHR for PFS, 1.19 [95% CI, 0.67-2.12]; P = .56; aHR for OS, 1.07 [95% CI, 0.54-2.12]; P = .85). Among patients who did not receive chemotherapy, mMGMT status was not associated with PFS or OS.

Conclusions and Relevance

This study suggests that mMGMT is associated with response to alkylating chemotherapy for low-grade and anaplastic gliomas and may be considered as a stratification factor in future clinical trials of patients with IDH-wild-type and IDH-mutant and codeleted tumors.

Dietary restriction of cysteine and methionine sensitizes gliomas to ferroptosis and induces alterations in energetic metabolism

Ferroptosis is mediated by lipid peroxidation of phospholipids containing polyunsaturated fatty acyl moieties. Glutathione, the key cellular antioxidant capable of inhibiting lipid peroxidation via the activity of the enzyme glutathione peroxidase 4 (GPX-4), is generated directly from the sulfur-containing amino acid cysteine, and indirectly from methionine via the transsulfuration pathway. Herein we show that cysteine and methionine deprivation (CMD) can synergize with the GPX4 inhibitor RSL3 to increase ferroptotic cell death and lipid peroxidation in both murine and human glioma cell lines and in ex vivo organotypic slice cultures. We also show that a cysteine-depleted, methionine-restricted diet can improve therapeutic response to RSL3 and prolong survival in a syngeneic orthotopic murine glioma model. Finally, this CMD diet leads to profound in vivo metabolomic, proteomic and lipidomic alterations, highlighting the potential for improving the efficacy of ferroptotic therapies in glioma treatment with a non-invasive dietary modification.

A cell state specific metabolic vulnerability to GPX4-dependent ferroptosis in glioblastoma

Glioma cells hijack developmental transcriptional programs to control cell state. During neural development, lineage trajectories rely on specialized metabolic pathways. However, the link between tumor cell state and metabolic programs is poorly understood in glioma. Here we uncover a glioma cell state-specific metabolic liability that can be leveraged therapeutically. To model cell state diversity, we generated genetically engineered murine gliomas, induced by deletion of p53 alone (p53) or with constitutively active Notch signaling (N1IC), a pathway critical in controlling cellular fate. N1IC tumors harbored quiescent astrocyte-like transformed cell states while p53 tumors were predominantly comprised of proliferating progenitor-like cell states. N1IC cells exhibit distinct metabolic alterations, with mitochondrial uncoupling and increased ROS production rendering them more sensitive to inhibition of the lipid hydroperoxidase GPX4 and induction of ferroptosis. Importantly, treating patient-derived organotypic slices with a GPX4 inhibitor induced selective depletion of quiescent astrocyte-like glioma cell populations with similar metabolic profiles.

Benign and Malignant Tumors of the Pineal Region

Pineal region tumors fall into five broad categories: benign pineal region tumors, glial tumors, papillary tumors, pineal parenchymal tumors, and germ cell tumors. Genetic and transcriptional studies have identified key chromosomal alterations in germinomas (RUNDC3A, ASAH1, LPL) and in pineocytomas/pineoblastomas (DROSHA/DICER1, RB1). Pineal region tumors generally present with symptoms of hydrocephalus including nausea, vomiting, papilledema, and the classical Parinaud's triad of upgaze paralysis, convergence-retraction nystagmus, and light-near pupillary dissociation. Workup requires neuroimaging and tissue diagnosis via biopsy. In germinoma cases, diagnosis may be made based on serum or CSF studies for alpha-fetoprotein or beta-HCG making the preferred treatment radiosurgery, thereby preventing the need for unnecessary surgeries. Treatment generally involves three steps: CSF diversion in cases of hydrocephalus, biopsy through endoscopic or stereotactic methods, and open surgical resection. Multiple surgical approaches are possible for approach to the pineal region. The original approach to the pineal region was the interhemispheric transcallosal first described by Dandy. The most common approach is the supracerebellar infratentorial approach as it utilizes a natural anatomic corridor for access to the pineal region. The paramedian or lateral supracerebellar infratentorial approach is another improvement that uses a similar anatomic corridor but allows for preservation of midline bridging veins; this minimizes the chance for brainstem or cerebellar venous infarction. Determination of the optimal approach relies on tumor characteristics, namely location of deep venous structures to the tumor along with the lateral eccentricity of the tumor. The immediate post-operative period is important as hemorrhage or swelling can cause obstructive hydrocephalus and lead to rapid deterioration. Adjuvant therapy, whether chemotherapy or radiation, is based on tumor pathology. Improvements within pineal surgery will require improved technology for access to the pineal region along with targeted therapies that can effectively treat and prevent recurrence of malignant pineal region tumors.

Convection-enhanced delivery of immunomodulatory therapy for high-grade glioma

The prognosis for glioblastoma has remained poor despite multimodal standard of care treatment, including temozolomide, radiation, and surgical resection. Further, the addition of immunotherapies, while promising in a number of other solid tumors, has overwhelmingly failed in the treatment of gliomas, in part due to the immunosuppressive microenvironment and poor drug penetrance to the brain. Local delivery of immunomodulatory therapies circumvents some of these challenges and has led to long-term remission in select patients. Many of these approaches utilize convection-enhanced delivery (CED) for immunological drug delivery, allowing high doses to be delivered directly to the brain parenchyma, avoiding systemic toxicity. Here, we review the literature encompassing immunotherapies delivered via CED-from preclinical model systems to clinical trials-and explore how their unique combination elicits an antitumor response by the immune system, decreases toxicity, and improves survival among select high-grade glioma patients.

Chronic convection-enhanced delivery of topotecan for patients with recurrent glioblastoma: a first-in-patient, single-centre, single-arm, phase 1b trial

BACKGROUND

Topotecan is cytotoxic to glioma cells but is clinically ineffective because of drug delivery limitations. Systemic delivery is limited by toxicity and insufficient brain penetrance, and, to date, convection-enhanced delivery (CED) has been restricted to a single treatment of restricted duration. To address this problem, we engineered a subcutaneously implanted catheter-pump system capable of repeated, chronic (prolonged, pulsatile) CED of topotecan into the brain and tested its safety and biological effects in patients with recurrent glioblastoma.

METHODS

We did a single-centre, open-label, single-arm, phase 1b clinical trial at Columbia University Irving Medical Center (New York, NY, USA). Eligible patients were at least 18 years of age with solitary, histologically confirmed recurrent glioblastoma showing radiographic progression after surgery, radiotherapy, and chemotherapy, and a Karnofsky Performance Status of at least 70. Five patients had catheters stereotactically implanted into the glioma-infiltrated peritumoural brain and connected to subcutaneously implanted pumps that infused 146 μM topotecan 200 μL/h for 48 h, followed by a 5-7-day washout period before the next infusion, with four total infusions. After the fourth infusion, the pump was removed and the tumour was resected. The primary endpoint of the study was safety of the treatment regimen as defined by presence of serious adverse events. Analyses were done in all treated patients. The trial is closed, and is registered with ClinicalTrials.gov, NCT03154996.

FINDINGS

Between Jan 22, 2018, and July 8, 2019, chronic CED of topotecan was successfully completed safely in all five patients, and was well tolerated without substantial complications. The only grade 3 adverse event related to treatment was intraoperative supplemental motor area syndrome (one [20%] of five patients in the treatment group), and there were no grade 4 adverse events. Other serious adverse events were related to surgical resection and not the study treatment. Median follow-up was 12 months (IQR 10-17) from pump explant. Post-treatment tissue analysis showed that topotecan significantly reduced proliferating tumour cells in all five patients.

INTERPRETATION

In this small patient cohort, we showed that chronic CED of topotecan is a potentially safe and active therapy for recurrent glioblastoma. Our analysis provided a unique tissue-based assessment of treatment response without the need for large patient numbers. This novel delivery of topotecan overcomes limitations in delivery and treatment response assessment for patients with glioblastoma and could be applicable for other anti-glioma drugs or other CNS diseases. Further studies are warranted to determine the effect of this drug delivery approach on clinical outcomes.

FUNDING

US National Institutes of Health, The William Rhodes and Louise Tilzer Rhodes Center for Glioblastoma, the Michael Weiner Glioblastoma Research Into Treatment Fund, the Gary and Yael Fegel Foundation, and The Khatib Foundation.

The Sledgehammer in Precision Medicine: Dexamethasone and Immunotherapeutic Treatment of Glioma

Understanding dexamethasone's effect on the immune microenvironment in glioma patients is of key importance. We performed a comprehensive literature review using the NCBI PubMed database for all articles meeting the following search criteria. ((dexamethasone[All Fields]) AND (glioma or glioblastoma)[Title/Abstract]) AND (immune or T cell or B cell or monocyte or neutrophil or macrophage). Forty-three manuscripts were deemed relevant to the topic at hand. Multiple clinical studies have linked dexamethasone use to decreased overall survival while preclinical studies in murine glioma models have demonstrated decreased tumor-infiltrating lymphocytes after dexamethasone administration.

Elderly traumatic central cord syndrome in the United States: a review of management and outcomes

INTRODUCTION

As the incidence of elderly spinal cord injury rises, improved understanding of risk profiles and outcomes is needed. This review summarizes clinical characteristics, management, and outcomes specific to the elderly (≥65-years) with acute traumatic central cord syndrome in the United States.

EVIDENCE AQUISITION

Literature review of the PubMed, Embase, and CINAHL databases (01/2007-03/2020) regarding elderly subjects with acute traumatic central cord syndrome.

EVIDENCE SYNTHESIS

Nine studies met inclusion criteria. Acute traumatic central cord syndrome was more common among married (50%), Caucasian (22-71%) males (63-86%) with an annual income <40,999 U.S. dollars (30%). Mechanisms consisted predominantly of traumatic falls (32-55%) and motor vehicle collisions (15-34%), with admission American Spinal Injury Association Impairment Scale grades D (25-79%) and C (21-51%). Mortality was 2-3%. American Spinal Injury Association Impairment Scale motor score, maximum canal compromise, and extent of parenchymal damage were predictors of one-year recovery. Greater comorbidities (heart failure, weight loss, coagulopathy, diabetes), lower income (<51,000 U.S. dollars), and age ≥80 were predictors of mortality. A substantial cohort underwent surgery (40-45%). Elderly patients were less likely to receive surgical intervention, and surgery timing had variable effects on recovery.

CONCLUSIONS

Elderly patients with acute traumatic central cord syndrome are uniquely at risk due to cumulative comorbidities, protracted recovery times, and unclear effects of surgical timing on outcomes. Prospective research should focus on validating age-specific risk factors, formalizing surgical indications, and delineating the impact of time to surgery on acute and long-term outcomes for this condition.

Single-cell characterization of macrophages in glioblastoma reveals MARCO as a mesenchymal pro-tumor marker

BACKGROUND

Macrophages are the most common infiltrating immune cells in gliomas and play a wide variety of pro-tumor and anti-tumor roles. However, the different subpopulations of macrophages and their effects on the tumor microenvironment remain poorly understood.

METHODS

We combined new and previously published single-cell RNA-seq data from 98,015 single cells from a total of 66 gliomas to profile 19,331 individual macrophages.

RESULTS

Unsupervised clustering revealed a pro-tumor subpopulation of bone marrow-derived macrophages characterized by the scavenger receptor MARCO, which is almost exclusively found in IDH1-wild-type glioblastomas. Previous studies have implicated MARCO as an unfavorable marker in melanoma and non-small cell lung cancer; here, we find that bulk MARCO expression is associated with worse prognosis and mesenchymal subtype. Furthermore, MARCO expression is significantly altered over the course of treatment with anti-PD1 checkpoint inhibitors in a response-dependent manner, which we validate with immunofluorescence imaging.

CONCLUSIONS

These findings illustrate a novel macrophage subpopulation that drives tumor progression in glioblastomas and suggest potential therapeutic targets to prevent their recruitment.

Predictors of six-month inability to return to work in previously employed subjects after mild traumatic brain injury: A TRACK-TBI pilot study

Introduction:

Return to work (RTW) is an important milestone of mild traumatic brain injury (mTBI) recovery. The objective of this study was to evaluate whether baseline clinical variables, three-month RTW, and three-month postconcussional symptoms (PCS) were associated with six-month RTW after mTBI.

Methods:

Adult subjects from the prospective multicenter Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot study with mTBI (Glasgow Coma Scale 13–15) who were employed at baseline, with completed three-and six-month RTW status, and three-month Acute Concussion Evaluation (ACE), were extracted. Univariate and multivariable analyses were performed for six-month RTW, with focus on baseline employment, three-month RTW, and three-month ACE domains (physical, cognitive, sleep, and/or emotional postconcussional symptoms (PCS)). Odds ratios (OR) and 95% confidence intervals [CI] were reported. Significance was assessed at p < 0.05.

Results:

In 152 patients aged 40.7 ± 15.0years, 72% were employed full-time at baseline. Three- and six-month RTW were 77.6% and 78.9%, respectively. At three months, 59.2%, 47.4%, 46.1% and 31.6% scored positive for ACE physical, cognitive, sleep, and emotional PCS domains, respectively. Three-month RTW predicted six-month RTW (OR = 19.80, 95% CI [7.61–51.52]). On univariate analysis, scoring positive in any three-month ACE domain predicted inability for six-month RTW (OR = 0.10–0.11). On multivariable analysis, emotional symptoms predicted inability to six-month RTW (OR = 0.19 [0.04–0.85]). Subjects who scored positive in all four ACE domains were more likely to be unable to RTW at six months (4 domains: 58.3%, vs. 0-to-3 domains: 9.5%; multivariable OR = 0.09 [0.02–0.33]).

Conclusions:

Three-month post-injury is an important time point at which RTW status and PCS should be assessed, as both are prognostic markers for six-month RTW. Clinicians should be particularly vigilant of patients who present with emotional symptoms, and patients with symptoms across multiple PCS categories, as these patients are at further risk of inability to RTW and may benefit from targeted evaluation and support.

Transferrin Receptor Is a Specific Ferroptosis Marker

Ferroptosis is a type of regulated cell death driven by the iron-dependent accumulation of oxidized polyunsaturated fatty acid-containing phospholipids. There is no reliable way to selectively stain ferroptotic cells in tissue sections to characterize the extent of ferroptosis in animal models or patient samples. We address this gap by immunizing mice with membranes from lymphoma cells treated with the ferroptosis inducer piperazine erastin and screening ~4,750 of the resulting monoclonal antibodies generated for their ability to selectively detect cells undergoing ferroptosis. We find that one antibody, 3F3 ferroptotic membrane antibody (3F3-FMA), is effective as a selective ferroptosis-staining reagent. The antigen of 3F3-FMA is identified as the human transferrin receptor 1 protein (TfR1). We validate this finding with several additional anti-TfR1 antibodies and compare them to other potential ferroptosis-detecting reagents. We find that anti-TfR1 and anti-malondialdehyde adduct antibodies are effective at staining ferroptotic tumor cells in multiple cell culture and tissue contexts.

Feng et al. find that 3F3-FMA detects ferroptotic cells by screening ~4,750 antibodies generated from mice immunized with membranes from DLBCL cells undergoing ferroptosis. The antigen of 3F3-FMA is the TfR1 protein. 3F3-FMA and other anti-TfR1 antibodies can be used to detect ferroptosis in cell culture and in cancer models.

Review of operative considerations in spinal cord stem cell therapy

Spinal cord injury (SCI) can permanently impair motor and sensory function and has a devastating cost to patients and the United States healthcare system. Stem cell transplantation for treatment of SCI is a new technique aimed at creating biological functional recovery. Operative techniques in stem cell transplantation for SCI are varied. We review various clinical treatment paradigms, surgical techniques and technical considerations important in SCI treatment. The NCBI PubMed database was queried for “SCI” and “stem cell” with a filter placed for “clinical trials”. Thirty-nine articles resulted from the search and 29 were included and evaluated by study authors. A total of 10 articles were excluded (9 not SCI focused or transplantation focused, 1 canine model). Key considerations for stem cell transplantation include method of delivery (intravenous, intrathecal, intramedullary, or excision and engraftment), time course of treatment, number of treatments and time from injury until treatment. There are no phase III clinical trials yet, but decreased time from injury to treatment and a greater number of stem cell injections both seem to increase the chance of functional recovery.

Reproducible analysis of disease space via principal components using the novel R package syndRomics

Biomedical data are usually analyzed at the univariate level, focused on a single primary outcome measure to provide insight into systems biology, complex disease states, and precision medicine opportunities. More broadly, these complex biological and disease states can be detected as common factors emerging from the relationships among measured variables using multivariate approaches. ‘Syndromics’ refers to an analytical framework for measuring disease states using principal component analysis and related multivariate statistics as primary tools for extracting underlying disease patterns. A key part of the syndromic workflow is the interpretation, the visualization, and the study of robustness of the main components that characterize the disease space. We present a new software package, syndRomics, an open-source R package with utility for component visualization, interpretation, and stability for syndromic analysis. We document the implementation of syndRomics and illustrate the use of the package in case studies of neurological trauma data.

Short-Term Outcomes following Standardized Admission of Late Preterm Infants to Family-Centered Care

OBJECTIVE

The study compares the short-term outcomes of late preterm infants (LPI) at an academic center in San Diego, California after a change in protocol that eliminated a previously mandatory 12-hour neonatal intensive care unit (NICU) observation period after birth.

STUDY DESIGN

This is a retrospective observational study examining all LPI born with gestational age 35 to 36^6/7 weeks between October 1, 2016 and October 31, 2017. A total of 189 infants were included in the review. Short-term outcomes were analyzed before and after the protocol change.

RESULTS

Transfers to the NICU from family-centered care (FCC) were considerably higher (23.2%) following the protocol change, compared to before (8.2%). More infants were transferred to the NICU for failed car seat tests postprotocol compared to preprotocol. Length of stay before the protocol change was 5.13 days compared to 4.80 days after.

CONCLUSION

LPI are vulnerable to morbidities after delivery and through discharge. We found an increase in failed car seat tests in LPI cared for in FCC after elimination of a mandatory NICU observation after birth. The transitions of care from delivery to discharge are key checkpoints in minimizing complications.

Focused Ultrasound-Mediated Blood-Brain Barrier Opening Increases Delivery and Efficacy of Etoposide for Glioblastoma Treatment

PURPOSE

Glioblastoma (GBM) is a devastating disease. With the current treatment of surgery followed by chemoradiation, outcomes remain poor, with median survival of only 15 months and a 5-year survival rate of 6.8%. A challenge in treating GBM is the heterogeneous integrity of the blood-brain barrier (BBB), which limits the bioavailability of systemic therapies to the brain. There is a growing interest in enhancing drug delivery by opening the BBB with the use of focused ultrasound (FUS). We hypothesize that an FUS-mediated BBB opening can enhance the delivery of etoposide for a therapeutic benefit in GBM.

METHODS AND MATERIALS

A murine glioma cell line (Pdgf⁺, Pten^-/-, P53^-/-) was orthotopically injected into B6(Cg)-Tyrc-2J/J mice to establish the syngeneic GBM model for this study. Animals were treated with FUS and microbubbles to open the BBB to enhance the delivery of systemic etoposide. Magnetic resonance (MR) imaging was used to evaluate the BBB opening and tumor progression. Liquid chromatography tandem mass spectrometry was used to measure etoposide concentrations in the intracranial tumors.

RESULTS

The murine glioma cell line is sensitive to etoposide in vitro. MR imaging and passive cavitation detection demonstrate the safe and successful BBB opening with FUS. The combined treatment of an FUS-mediated BBB opening and etoposide decreased tumor growth by 45% and prolonged median overall survival by 6 days: an approximately 30% increase. The FUS-mediated BBB opening increased the brain tumor-to-serum ratio of etoposide by 3.5-fold and increased the etoposide concentration in brain tumor tissue by 8-fold compared with treatment without ultrasound.

CONCLUSIONS

The current study demonstrates that BBB opening with FUS increases intratumoral delivery of etoposide in the brain, resulting in local control and overall survival benefits.

Semaphorin 3A mediated brain tumor stem cell proliferation and invasion in EGFRviii mutant gliomas

BACKGROUND

Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults, with a median survival of approximately 15 months. Semaphorin 3A (Sema3A), known for its axon guidance and antiangiogenic properties, has been implicated in GBM growth. We hypothesized that Sema3A directly inhibits brain tumor stem cell (BTSC) proliferation and drives invasion via Neuropilin 1 (Nrp1) and Plexin A1 (PlxnA1) receptors.

METHODS

GBM BTSC cell lines were assayed by immunostaining and PCR for levels of Semaphorin 3A (Sema3A) and its receptors Nrp1 and PlxnA1. Quantitative BrdU, cell cycle and propidium iodide labeling assays were performed following exogenous Sema3A treatment. Quantitative functional 2-D and 3-D invasion assays along with shRNA lentiviral knockdown of Nrp1 and PlxnA1 are also shown. In vivo flank studies comparing tumor growth of knockdown versus control BTSCs were performed. Statistics were performed using GraphPad Prism v7.

RESULTS

Immunostaining and PCR analysis revealed that BTSCs highly express Sema3A and its receptors Nrp1 and PlxnA1, with expression of Nrp1 in the CD133 positive BTSCs, and absence in differentiated tumor cells. Treatment with exogenous Sema3A in quantitative BrdU, cell cycle, and propidium iodide labeling assays demonstrated that Sema3A significantly inhibited BTSC proliferation without inducing cell death. Quantitative functional 2-D and 3-D invasion assays showed that treatment with Sema3A resulted in increased invasion. Using shRNA lentiviruses, knockdown of either NRP1 or PlxnA1 receptors abrogated Sema3A antiproliferative and pro-invasive effects. Interestingly, loss of the receptors mimicked Sema3A effects, inhibiting BTSC proliferation and driving invasion. Furthermore, in vivo studies comparing tumor growth of knockdown and control infected BTSCs implanted into the flanks of nude mice confirmed the decrease in proliferation with receptor KD.

CONCLUSIONS

These findings demonstrate the importance of Sema3A signaling in GBM BTSC proliferation and invasion, and its potential as a therapeutic target.

Basal impulses: findings from the last twenty years on impulsivity and reward pathways using deep brain stimulation

INTRODUCTION

Deep brain stimulation (DBS) is an important treatment modality for movement disorders. Its role in tasks and processes of higher cortical function continues to increase in importance and relevance. This systematic review investigates the impact of DBS on measures of impulsivity.

EVIDENCE ACQUISITION

A total of 45 studies were collated from PubMed (30 prospective, 8 animal, 4 questionnaire-based, and 3 computational models), excluding case reports and review articles. Two areas extensively studied are the subthalamic nucleus (STN) and nucleus accumbens (NAc).

EVIDENCE SYNTHESIS

While both are part of the basal ganglia, the STN and NAc have extensive connections to the prefrontal cortex, cingulate cortex, and limbic system. Therefore, understanding cause and treatment of impulsivity requires understanding motor pathways, learning, memory, and emotional processing. DBS of the STN and NAc shell can increase objective measures of impulsivity, as measured by reaction times or reward-based learning, independent from patient insight. The ability for DBS to treat impulse control disorders, and also cause and/or worsen impulsivity in Parkinson's disease, may be explained by the affected closely-related neuroanatomical areas with discrete and sometimes opposing functions.

CONCLUSIONS

As newer, more refined DBS technology emerges, large-scale prospective studies specifically aimed at treatment of impulsivity disorders are needed.

B-Cell Lymphoma 2 (Bcl-2) and Regulation of Apoptosis after Traumatic Brain Injury: A Clinical Perspective

Background and Objectives: The injury burden after head trauma is exacerbated by secondary sequelae, which leads to further neuronal loss. B-cell lymphoma 2 (Bcl-2) is an anti-apoptotic protein and a key modulator of the programmed cell death (PCD) pathways. The current study evaluates the clinical evidence on Bcl-2 and neurological recovery in patients after traumatic brain injury (TBI). Materials and Methods: All studies in English were queried from the National Library of Medicine PubMed database using the following search terms: (B-cell lymphoma 2/Bcl-2/Bcl2) AND (brain injury/head injury/head trauma/traumatic brain injury) AND (human/patient/subject). There were 10 investigations conducted on Bcl-2 and apoptosis in TBI patients, of which 5 analyzed the pericontutional brain tissue obtained from surgical decompression, 4 studied Bcl-2 expression as a biomarker in the cerebrospinal fluid (CSF), and 1 was a prospective randomized trial. Results: Immunohistochemistry (IHC) in 94 adults with severe TBI showed upregulation of Bcl-2 in the pericontusional tissue. Bcl-2 was detected in 36-75% of TBI patients, while it was generally absent in the non-TBI controls, with Bcl-2 expression increased 2.9- to 17-fold in TBI patients. Terminal deoxynucleotidyl transferase-mediated biotinylated dUTP nick-end labeling (TUNEL) positivity for cell death was detected in 33-73% of TBI patients. CSF analysis in 113 TBI subjects (90 adults, 23 pediatric patients) showed upregulation of Bcl-2 that peaked on post-injury day 3 and subsequently declined after day 5. Increased Bcl-2 in the peritraumatic tissue, rising CSF Bcl-2 levels, and the variant allele of rs17759659 are associated with improved mortality and better outcomes on the Glasgow Outcome Score (GOS). Conclusions: Bcl-2 is upregulated in the pericontusional brain and CSF in the acute period after TBI. Bcl-2 has a neuroprotective role as a pro-survival protein in experimental models, and increased expression in patients can contribute to improvement in clinical outcomes. Its utility as a biomarker and therapeutic target to block neuronal apoptosis after TBI warrants further evaluation.

Substance use on admission toxicology screen is associated with peri-injury factors and six-month outcome after traumatic brain injury: A TRACK-TBI Pilot study

Substance use is commonly associated with traumatic brain injury (TBI). We investigate associations between active substance use, peri-injury factors, and outcome after TBI across three U.S. Level I trauma centers. TBI subjects from the prospective Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot (TRACK-TBI Pilot) with Marshall computed tomography (CT) score 1-3, no neurosurgical procedure/operation, and admission urine toxicology screen (tox+/-) were extracted. Associations between tox+/-, comorbidities, hospital variables, and six-month functional (GOSE) and neuropsychiatric (PCL-C, BSI18, RPQ-13, SWLS) outcomes were analyzed. Multivariable regression was performed for associations significant on univariate analysis with odds ratios (mOR) presented. Significance assessed at p < 0.05. In 133 subjects, tox+/tox- were 29.1%/72.9%. Tox+ was younger (35.5/43.6-years, p = 0.018), trended toward male sex (80.6%/63.9%, p = 0.067), was associated with history of seizures (27.8%/10.3%, p = 0.012), self-reported substance use (44.4%/17.5%, p = 0.001), prior TBI (58.8%/34.1%, p = 0.009), GCS < 15 (69.4%/48.4%, p = 0.031) and blood alcohol level >0.08-mg/dl (55.6%/30.8%, p = 0.022). In CT-negative subjects, tox+ was associated with increased hospital admission (95.7%/66.7%, p = 0.034). At six-months, tox+ was associated with screening positive for post-traumatic stress disorder (PCL-C: 40.0%/15.9%; mOR = 8.24, p = 0.022) and psychiatric symptoms (BSI18: 40.0%/14.3%, mOR = 11.06, p = 0.023). Active substance use in TBI may confound GCS assessment, triage to higher level of care, and be associated with increased six-month neuropsychiatric symptoms. Substance use screening should be integrated into standard emergency/acute care TBI protocols to optimize management and resource utilization. Clinicians should be vigilant in providing education, counselling, and follow-up for TBI patients with substance use.

Concussion and Mild-Traumatic Brain Injury in Rural Settings: Epidemiology and Specific Health Care Considerations

Background  Mild-traumatic brain injury (mTBI) and concussions cause significant morbidity. To date, synthesis of specific health care disparities and gaps in care for rural mTBI/concussion patients remains needed. Methods  A comprehensive literature search was performed using PubMed database for English articles with keywords "rural" and ("concussion" or "mild traumatic brain injury") from 1991 to 2019. Eighteen articles focusing on rural epidemiology ( n = 5), management/cost ( n = 5), military ( n = 2), and concussion prevention/return to play ( n = 6) were included. Results  mTBI/concussion incidence was higher in rural compared with urban areas. Compared with urban patients, rural patients were at increased risk for vehicular injuries, lifetime number of concussions, admissions for observation without neuroimaging, and injury-related costs. Rural patients were less likely to utilize ambulatory and mental health services following mTBI/concussion. Rural secondary schools had decreased access to certified personnel for concussion evaluation, and decreased use of standardized assessment instruments/neurocognitive testing. While school coaches were aware of return-to-play laws, mTBI/concussion education rates for athletes and parents were suboptimal in both settings. Rural veterans were at increased risk for postconcussive symptoms and posttraumatic stress. Telemedicine in rural/low-resource areas is an emerging tool for rapid evaluation, triage, and follow-up. Conclusions  Rural patients are at unique risk for mTBI/concussions and health care costs. Barriers to care include lower socioeconomic status, longer distances to regional medical center, and decreased availability of neuroimaging and consultants. Due to socioeconomic and distance barriers, rural schools are less able to recruit personnel certified for concussion evaluation. Telemedicine is an emerging tool for remote triage and evaluation.

Radiation-Induced Lipid Peroxidation Triggers Ferroptosis and Synergizes with Ferroptosis Inducers

Although radiation is widely used to treat cancers, resistance mechanisms often develop and involve activation of DNA repair and inhibition of apoptosis. Therefore, compounds that sensitize cancer cells to radiation via alternative cell death pathways are valuable. We report here that ferroptosis, a form of nonapoptotic cell death driven by lipid peroxidation, is partly responsible for radiation-induced cancer cell death. Moreover, we found that small molecules activating ferroptosis through system xc- inhibition or GPX4 inhibition synergize with radiation to induce ferroptosis in several cancer types by enhancing cytoplasmic lipid peroxidation but not increasing DNA damage or caspase activation. Ferroptosis inducers synergized with cytoplasmic irradiation, but not nuclear irradiation. Finally, administration of ferroptosis inducers enhanced the antitumor effect of radiation in a murine xenograft model and in human patient-derived models of lung adenocarcinoma and glioma. These results suggest that ferroptosis inducers may be effective radiosensitizers that can expand the efficacy and range of indications for radiation therapy.

The Current State of Rural Neurosurgical Practice: An International Perspective

Introduction:

Rural and low-resource areas have diminished capacity to care for neurosurgical patients due to lack of infrastructure, healthcare investment, and training programs. This review summarizes the range of rural neurosurgical procedures, novel mechanisms for delivering care, rapid training programs, and outcome differences across international rural neurosurgical practice.

Methods:

A comprehensive literature search was performed for English language manuscripts with keywords “rural” and “neurosurgery” using the National Library of Medicine PubMed database (01/1971–06/2017). Twenty-four articles focusing on rural non-neurosurgical practice were included.

Results:

Time to care and/or surgery and shortage of trained personnel remain the strongest risk factors for mortality and poor outcome. Telemedicine consults to regional centers with neurosurgery housestaff have potential for increased timeliness of diagnosis/triage, improved time to surgery, and reductions in unnecessary transfers in remote areas. Mobile neurosurgery teams have been deployed with success in nations with large transport distances precluding initial transfers. Common neurosurgical procedures involve trauma mechanisms; accordingly, training programs for nonneurosurgery medical personnel on basic assessment and operative techniques have been successful in resource-deficient settings where neurosurgeons are unavailable.

Conclusions:

Protracted transport times, lack of resources/training, and difficulty retaining specialists are barriers to successful outcomes. Advances in telemedicine, mobile neurosurgery, and training programs for urgent operative techniques have been implemented efficaciously. Development of guidelines for paired partnerships between rural centers and academic hospitals, supplying surplus technology to rural areas, and rapid training of qualified local surgical personnel can create sustainable feed-forward programs for trainees and infrastructural solutions to address challenges in rural neurosurgery.

Anterior Versus Transforaminal Lumbar Interbody Fusion: Perioperative Risk Factors and 30-Day Outcomes

Background

Operative management of lower back pain often necessitates anterior lumbar interbody fusion (ALIF) or transforaminal lumbar interbody fusion (TLIF). Specific pathoanatomic advantages and indications exist for both approaches, and few studies to date have characterized comparative early outcomes.

Methods

Adult patients undergoing elective ALIF or TLIF operations were abstracted from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) years 2011-2014. Univariate analyses were performed by surgery cohort for each outcome and adjusted for demographic/clinical variables (age ≥ 65, sex, race, body mass index, American Society of Anesthesiologists physical classification score, functional status, inpatient/outpatient status, smoking, hypertension, Charlson Comorbidity Index) using multivariable regression. Means, standard errors, mean differences (B), odds ratios (ORs), and associated 95% confidence intervals (CIs) are reported. Significance was assessed at P < .05.

Results

Of 8263 subjects (ALIF: 4325, TLIF: 3938), ALIF subjects were younger, less obese, less physically impaired, and had significantly lower rates of hypertension, diabetes, coagulopathy, and previous cardiac surgery. On multivariable analysis, ALIF associated with shorter operative time (B = -11.80 minutes, 95% CI [-16.48, -7.12]; P < .001). Transforaminal lumbar interbody fusion was associated with increased incidence of urinary tract infections (UTIs; OR = 1.57, 95% CI [1.10, 2.26]; P = .013) and of blood transfusions (OR = 1.19, 95% CI [1.04, 1.37]; P = .012). Multivariate analysis also demonstrated TLIF associated with shorter hospital length of stay (B = -0.27 days, 95% CI [-0.54, -0.01]; P = .041), and fewer cases of pneumonia (OR = 0.55, 95% CI [0.32, 0.94]; P = .029) and prolonged ventilator dependency (OR = 0.33, 95% CI [0.12, 0.84]; P = .021).

Conclusions

Comparatively, ALIF patients experienced decreased operative time and decreased incidence of postoperative UTIs and blood transfusions. Anterior lumbar interbody fusion patients were more likely to suffer postoperative pulmonary complications and longer hospital stays. Our data support the notion that both anterior and transforaminal surgical approaches perform comparably in context of 30-day perioperative outcomes.

Apolipoprotein E Epsilon 4 Genotype, Mild Traumatic Brain Injury, and the Development of Chronic Traumatic Encephalopathy

The annual incidence of mild traumatic brain injury (MTBI) is 3.8 million in the USA with 10⁻15% experiencing persistent morbidity beyond one year. Chronic traumatic encephalopathy (CTE), a neurodegenerative disease characterized by accumulation of hyperphosphorylated tau, can occur with repetitive MTBI. Risk factors for CTE are challenging to identify because injury mechanisms of MTBI are heterogeneous, clinical manifestations and management vary, and CTE is a postmortem diagnosis, making prospective studies difficult. There is growing interest in the genetic influence on head trauma and development of CTE. Apolipoprotein epsilon 4 (APOE-ε4) associates with many neurologic diseases, and consensus on the ε4 allele as a risk factor is lacking. This review investigates the influence of APOE-ε4 on MTBI and CTE. A comprehensive PubMed literature search (1966 to 12 June 2018) identified 24 unique reports on the topic (19 MTBI studies: 8 athletic, 5 military, 6 population-based; 5 CTE studies: 4 athletic and military, 1 leucotomy group). APOE-ε4 genotype is found to associate with outcomes in 4/8 athletic reports, 3/5 military reports, and 5/6 population-based reports following MTBI. Evidence on the association between APOE-ε4 and CTE from case series is equivocal. Refining modalities to aid CTE diagnosis in larger samples is needed in MTBI.

Update on critical care for acute spinal cord injury in the setting of polytrauma

Traumatic spinal cord injury (SCI) often occurs in patients with concurrent traumatic injuries in other body systems. These patients with polytrauma pose unique challenges to clinicians. The current review evaluates existing guidelines and updates the evidence for prehospital transport, immobilization, initial resuscitation, critical care, hemodynamic stability, diagnostic imaging, surgical techniques, and timing appropriate for the patient with SCI who has multisystem trauma. Initial management should be systematic, with focus on spinal immobilization, timely transport, and optimizing perfusion to the spinal cord. There is general evidence for the maintenance of mean arterial pressure of > 85 mm Hg during immediate and acute care to optimize neurological outcome; however, the selection of vasopressor type and duration should be judicious, with considerations for level of injury and risks of increased cardiogenic complications in the elderly. Level II recommendations exist for early decompression, and additional time points of neurological assessment within the first 24 hours and during acute care are warranted to determine the temporality of benefits attributable to early surgery. Venous thromboembolism prophylaxis using low-molecular-weight heparin is recommended by current guidelines for SCI. For these patients, titration of tidal volumes is important to balance the association of earlier weaning off the ventilator, with its risk of atelectasis, against the risk for lung damage from mechanical overinflation that can occur with prolonged ventilation. Careful evaluation of infection risk is a priority following multisystem trauma for patients with relative immunosuppression or compromise. Although patients with polytrauma may experience longer rehabilitation courses, long-term neurological recovery is generally comparable to that in patients with isolated SCI after controlling for demographics. Bowel and bladder disorders are common following SCI, significantly reduce quality of life, and constitute a focus of targeted therapies. Emerging biomarkers including glial fibrillary acidic protein, S100β, and microRNAs for traumatic SCIs are presented. Systematic management approaches to minimize sources of secondary injury are discussed, and areas requiring further research, implementation, and validation are identified.

Emergency department blood alcohol level associates with injury factors and six-month outcome after uncomplicated mild traumatic brain injury

The relationship between blood alcohol level (BAL) and mild traumatic brain injury (mTBI) remains in need of improved characterization. Adult patients suffering mTBI without intracranial pathology on computed tomography (CT) from the prospective Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot study with emergency department (ED) Glasgow Coma Scale (GCS) 13-15 and recorded blood alcohol level (BAL) were extracted. BAL≥80-mg/dl was set as proxy for excessive use. Multivariable regression was performed for patients with six-month Glasgow Outcome Scale-Extended (GOSE; functional recovery) and Wechsler Adult Intelligence Scale Processing Speed Index Composite Score (WAIS-PSI; nonverbal processing speed), using BAL≥80-mg/dl and <80-mg/dl cohorts, adjusting for demographic/injury factors. Overall, 107 patients were aged 42.7±16.8-years, 67.3%-male, and 80.4%-Caucasian; 65.4% had BAL=0-mg/dl, 4.6% BAL<80-mg/dl, and 30.0% BAL≥80-mg/dl (range 100-440-mg/dl). BAL differed across loss of consciousness (LOC; none: median 0-mg/dl [interquartile range (IQR) 0-0], <30-min: 0-mg/dl [0-43], ≥30-min: 224-mg/dl [50-269], unknown: 108-mg/dl [0-232]; p=0.002). GCS<15 associated with higher BAL (19-mg/dl [0-204] vs. 0-mg/dl [0-20]; p=0.013). On univariate analysis, BAL≥80-mg/dl associated with less-than-full functional recovery (GOSE≤7; 38.1% vs. 11.5%; p=0.025) and lower WAIS-PSI (92.4±12.7, 30th-percentile vs. 105.1±11.7, 63rd-percentile; p<0.001). On multivariable regression BAL≥80-mg/dl demonstrated an odds ratio of 8.05 (95% CI [1.35-47.92]; p=0.022) for GOSE≤7 and an adjusted mean decrease of 8.88-points (95% CI [0.67-17.09]; p=0.035) on WAIS-PSI. Day-of-injury BAL>80-mg/dl after uncomplicated mTBI was associated with decreased GCS score and prolongation of reported LOC. BAL may be a biomarker for impaired return to baseline function and decreased nonverbal processing speed at six-months postinjury. Future confirmatory studies are needed.

Selective Serotonin Reuptake Inhibitors for Treating Neurocognitive and Neuropsychiatric Disorders Following Traumatic Brain Injury: An Evaluation of Current Evidence

The prevalence of neuropsychiatric disorders following traumatic brain injury (TBI) is 20%-50%, and disorders of mood and cognition may remain even after recovery of neurologic function is achieved. Selective serotonin reuptake inhibitors (SSRI) block the reuptake of serotonin in presynaptic cells to lead to increased serotonergic activity in the synaptic cleft, constituting first-line treatment for a variety of neurocognitive and neuropsychiatric disorders. This review investigates the utility of SSRIs in treating post-TBI disorders. In total, 37 unique reports were consolidated from the Cochrane Central Register and PubMed (eight randomized-controlled trials (RCTs), nine open-label studies, 11 case reports, nine review articles). SSRIs are associated with improvement of depressive but not cognitive symptoms. Pooled analysis using the Hamilton Depression Rating Scale demonstrate a significant mean decrease of depression severity following sertraline compared to placebo-a result supported by several other RCTs with similar endpoints. Evidence from smaller studies demonstrates mood improvement following SSRI administration with absent or negative effects on cognitive and functional recovery. Notably, studies on SSRI treatment effects for post-traumatic stress disorder after TBI remain absent, and this represents an important direction of future research. Furthermore, placebo-controlled studies with extended follow-up periods and concurrent biomarker, neuroimaging and behavioral data are necessary to delineate the attributable pharmacological effects of SSRIs in the TBI population.

Risk factors for 30-day outcomes in elective anterior versus posterior cervical fusion: A matched cohort analysis

OBJECTIVE

Cervical spine fusion is the preferred treatment modality for a variety of degenerative and/or myelopathic disorders. Surgeons select between two approaches (anterior or posterior cervical fusion [ACF; PCF]) based on pathoanatomical features and spinal levels involved. Complications and outcome profiles between the approaches following elective surgery have not been systematically investigated.

METHODS

Adult patients undergoing elective ACF or PCF were extracted from the American College of Surgeons National Surgical Quality Improvement Program years 2011-2014. Five hundred twenty-eight patients (264 ACF and 264 PCF) were matched 1:1 by age, sex, functional status, vertebral levels operated, and the American Society of Anesthesiologists classification. Multivariable regression was performed by surgical approach for operation time, complications, hospital length of stay (HLOS), and discharge destination, controlling for body mass index and comorbidities. Mean differences (B), odds ratios (ORs), and 95% confidence intervals (CIs) are reported.

RESULTS

Compared to ACF, PCF was associated with increased odds of blood transfusions >1 unit (OR = 4.31, 95% CI [1.18-15.75]; P = 0.027) and failure to discharge to home (OR = 3.68 [2.17-6.25]; P < 0.001), and increased mean HLOS (B = 1.72 days [1.19-2.26]; P < 0.001). No differences in operation time, other complications, or reoperation rates were found by surgical approach.

CONCLUSIONS

In a matched cohort analysis by age, sex, functional and physical status, and vertebral levels, elective PCF is associated with increased HLOS and increased likelihood of failing to discharge to home compared to ACF without increased risk of 30-day complications. Increased blood transfusion volume is noted for patients undergoing PCF. Future prospective studies are warranted.

A review and update on the current and emerging clinical trials for the acute management of cervical spine and spinal cord injuries - Part III

INTRODUCTION

Spinal cord injury (SCI) is a debilitating disease with an average annual incidence of 29.5 persons per million worldwide. Hence, it is critical to refine and bolster evidence to inform standards of care and improve outcomes.

EVIDENCE ACQUISITION

In 2013 the American Association of Neurological Surgeons and the Congress of Neurological Surgeons released updated management guidelines for acute cervical spine injuries and SCI; here, we explore cervical SCI treatment trials since the 2013 publication. Of 56 studies published in the Cochrane Library Central Register of Controlled Trials, 19 met inclusion criterion of acute cervical spine injury and are summarized across 4 subcategories: diagnosis, surgical stabilization, scopes/instrumentation, and therapeutic outcomes.

EVIDENCE SYNTHESIS

We confirm the utility of computed tomography for diagnosis, and improved outcomes associated with early (<24 hours) decompressive surgery. We describe advances in laryngoscopy and intubation under various SCI indications. We explore the benefits of continuous positive airway pressure protocols for reducing respiratory insufficiency, and patient education standards for transfer and mobility success. We report on ongoing randomized controlled trials (RCT) for surgical and therapeutic approaches for subpopulations of interest, including incomplete cord lesion, canal stenosis, and riluzole pharmacotherapy. We recommend a large, multicenter, prospective confirmatory RCT to assess the impact of timing of surgery versus conservative management in an effort to generate Class I evidence on the topic.

CONCLUSIONS

Such a study should utilize shared, common variables as outlined by the National Institutes of Health SCI Common Data Elements to enable international collaboration and data pooling for robust, reproducible analyses.

Odontoid fractures in the octogenarian: a systematic review and meta-analysis

INTRODUCTION

Odontoid fractures (OF) are the most frequent cervical spine fracture type in the elderly, often following low-velocity falls. The rise in life expectancies has led to an increase in octogenarians suffering OF, for which the optimal treatment remains undetermined.

EVIDENCE ACQUISITION

A comprehensive search was conducted (National Library of Medicine MEDLINE, Cochrane Central Register of Controlled Trials) for all articles through 03/2016. Articles were included if the study population evaluated treatment modalities in OF patients aged ≥80-years. Outcomes assessed were mortality, complications, osseous union, and fracture stability. Pooled odds ratios (OR) and 95% confidence intervals (CI) are reported.

EVIDENCE SYNTHESIS

Across 22 case series/retrospective studies, attributable mortality for surgery was 5.4% (8/149) vs. 10.1% (10/99) for nonsurgery (P=0.159). Surgery patients suffered higher complications rates (38.9%, 58/149; vs. 24.5%, 26/106); OR 1.96 ([1.13-3.40], P=0.016). Osseous union was better achieved with surgery (68.5%, 37/54; vs. 43.2%, 16/37); OR 2.86 ([1.20-6.80]; P=0.016). Fracture stability was better achieved with surgery (86.0%, 49/57; vs. 63.6%, 28/44); OR 3.50 ([1.33-9.21], P=0.009).

CONCLUSIONS

In general, octogenarians undergoing surgery for OF showed higher fusion and stability rates compared to nonsurgery, which may be due in part to surgical selection criteria, surgeon preference and patient comorbidities. Higher complications were observed for surgery patients, while no differences were observed for mortality. Prospective trials are greatly needed to identify the optional treatment modality and predictors of clinical outcome in octogenarians suffering OF.

Elective laminectomy and excision of the thoracic spine neoplasm: an evaluation of early outcomes

BACKGROUND

Laminectomy with excision of spinal neoplasms is commonly performed. The current study examines risk profiles associated with elective laminectomies of benign, malignant primary, and secondary/metastatic neoplasms of the thoracic spine.

METHODS

Adult patients undergoing elective thoracic laminectomy and excision of spinal neoplasm were abstracted from ACS-NSQIP years 2011-2014. Patients were classified into three cohorts: benign primary, malignant primary, secondary/metastatic. Univariate and multivariable analyses compared operation time, early complications, hospital length of stay (HLOS), and discharge destination across cohorts.

RESULTS

One-hundred sixty patients were included, aged 58.0±14.8-years. Mean operation time was 209.23±101.52 minutes and cohorts did not differ significantly on multivariable analysis. Mean HLOS was 6.10±7.14 days and did not differ by cohort. Early complications were observed in 15.6% of patients; secondary/metastatic patients associated with increased odds of >1 unit of blood transfusion, but not overall complications. Failure to be discharged home occurred in 31.8% of patients (benign primary: 30.0%, malignant primary: 66.6%, secondary/metastatic: 10.5%; P<0.001). Malignant primary tumors associated with increased multivariable odds of failure to be discharged home (OR 3.63, 95% CI [1.09, 12.10], P=0.036). Tumor location (extradural, intradural/extramedullary, intramedullary) was not a significant predictor of outcomes. A higher number of concurrent fusions were observed for secondary/metastatic laminectomies (benign primary: 7.3%; malignant primary: 5.5%; secondary/metastatic: 36.8%; P<0.001).

CONCLUSIONS

Comparable performance on operation time and HLOS between neoplasm cohorts suggests broad indication of resectional laminectomies for elective treatment. Primary malignant thoracic spine tumors may require higher levels of early postdischarge care. Future studies are needed to confirm these findings.

Circadian variability of the initial Glasgow Coma Scale score in traumatic brain injury patients

Introduction

The Glasgow Coma Scale (GCS) score is the primary method of assessing consciousness after traumatic brain injury (TBI), and the clinical standard for classifying TBI severity. There is scant literature discerning the influence of circadian rhythms or emergency department (ED) arrival hour on this important clinical tool.

Methods

Retrospective cohort analysis of adult patients suffering blunt TBI using the National Sample Program of the National Trauma Data Bank, years 2003–2006. ED arrival GCS score was characterized by midday (10 a.m.–4 p.m.) and midnight (12 a.m.–6 a.m.) cohorts (N=24548). Proportions and standard errors are reported for descriptive data. Multivariable regressions using odds ratios (OR), mean differences (B), and their associated 95% confidence intervals [CI] were performed to assess associations between ED arrival hour and GCS score. Statistical significance was assessed at p<0.05.

Results

Patients were 42.48±0.13-years-old and 69.5% male. GCS score was 12.68±0.13 (77.2% mild, 5.2% moderate, 17.6% severe-TBI). Overall, patients were injured primarily via motor vehicle accidents (52.2%) and falls (24.2%), and 85.7% were admitted to hospital (33.5% ICU). Injury severity score did not differ between day and nighttime admissions.

Nighttime admissions associated with decreased systemic comorbidities (p<0.001) and increased likelihood of alcohol abuse and drug intoxication (p<0.001). GCS score demonstrated circadian rhythmicity with peak at 12 p.m. (13.03±0.08) and nadir at 4am (12.12±0.12). Midnight patients demonstrated lower GCS (12 a.m.–6 a.m.: 12.23±0.04; 10 a.m.–4 p.m.: 12.95±0.03, p<0.001). Multivariable regression adjusted for demographic and injury factors confirmed that midnight-hours independently associated with decreased GCS (B=−0.29 [−0.40, −0.19]).

In patients who did not die in ED or go directly to surgery (N=21862), midnight-hours (multivariable OR 1.73 [1.30–2.31]) associated with increased likelihood of ICU admission; increasing GCS score (per-unit OR 0.82 [0.80–0.83]) associated with decreased odds. Notably, the interaction factor ED GCS score*ED arrival hour independently demonstrated OR 0.96 [0.94–0.98], suggesting that the influence of GCS score on ICU admission odds is less important at night than during the day.

Conclusions

Nighttime TBI patients present with decreased GCS scores and are admitted to ICU at higher rates, yet have fewer prior comorbidities and similar systemic injuries. The interaction between nighttime hours and decreased GCS score on ICU admissions has important implications for clinical assessment/triage.

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Glasgow Coma Scale (GCS) score demonstrates circadian rhythmicity following TBI.

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Midnight-hours (12 a.m.–6 a.m.) independently associate with decreased GCS score.

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Midnight-hours independently associate with increased likelihood of ICU admission.

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Influence of GCS score on ICU admission is less important at night than in daytime.

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Nighttime TBIs present with less systemic comorbidities&increased substance use.

A review and update on the guidelines for the acute management of cervical spinal cord injury - Part II

Acute traumatic spinal cord injury (SCI) is a debilitating worldwide disease with an estimated annual incidence of 10 to 83 affected individuals per million inhabitants. These injuries typically impact younger individuals and reduce quality-adjusted life years with estimated lifetime costs exceeding $4 million per person. Hence it is critical to establish and refine clear practice guidelines for acute management of SCI. In 2013 the Joint Section on Disorders of the Spine and Peripheral Nerves of the American Association of Neurological Surgeons (AANS) and the Congress of Neurological Surgeons (CNS) released a revision of the 2002 guidelines for Cervical SCI. In the present report we explore seven subsections for management of specific cervical injury types, review key supporting literature, and provide an update on recent studies since the publication of the 2013 guidelines. Our review finds a paucity of Level I and Level II treatment recommendations for cervical spine injuries, with the exception of subaxial cervical spine injury classification and surgical management for Type II odontoid fractures in the elderly. We recommend the systematic implementation of large randomized controlled studies across diverse demographics and ethnicities, injury mechanisms and morphologies to address pressing limitations in the current literature. The cohesive effort to adopt the 2013 AANS/CNS Guidelines and the National Institutes of Health (NIH)/National Institute of Neurological Disorders and Stroke (NINDS) Common Data Elements for SCI as part of a multicenter international approach will enable reproducible data collection and robust analyses toward achieving this goal.