Interindividual variation in human cortical cell type abundance and expression

Single-cell transcriptomic studies have identified a conserved set of neocortical cell types from small postmortem cohorts. We extended these efforts by assessing cell type variation across 75 adult individuals undergoing epilepsy and tumor surgeries. Nearly all nuclei map to one of 125 robust cell types identified in the middle temporal gyrus. However, we found interindividual variance in abundances and gene expression signatures, particularly in deep-layer glutamatergic neurons and microglia. A minority of donor variance is explainable by age, sex, ancestry, disease state, and cell state. Genomic variation was associated with expression of 150 to 250 genes for most cell types. This characterization of cellular variation provides a baseline for cell typing in health and disease.

Local connectivity and synaptic dynamics in mouse and human neocortex

We present a unique, extensive, and open synaptic physiology analysis platform and dataset. Through its application, we reveal principles that relate cell type to synaptic properties and intralaminar circuit organization in the mouse and human cortex. The dynamics of excitatory synapses align with the postsynaptic cell subclass, whereas inhibitory synapse dynamics partly align with presynaptic cell subclass but with considerable overlap. Synaptic properties are heterogeneous in most subclass-to-subclass connections. The two main axes of heterogeneity are strength and variability. Cell subclasses divide along the variability axis, whereas the strength axis accounts for substantial heterogeneity within the subclass. In the human cortex, excitatory-to-excitatory synaptic dynamics are distinct from those in the mouse cortex and vary with depth across layers 2 and 3.

Functional Outcomes Over the First Year After Moderate to Severe Traumatic Brain Injury in the Prospective, Longitudinal TRACK-TBI Study

Importance

Moderate to severe traumatic brain injury (msTBI) is a major cause of death and disability in the US and worldwide. Few studies have enabled prospective, longitudinal outcome data collection from the acute to chronic phases of recovery after msTBI.

Objective

To prospectively assess outcomes in major areas of life function at 2 weeks and 3, 6, and 12 months after msTBI.

Design, Setting, and Participants

This cohort study, as part of the Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study, was conducted at 18 level 1 trauma centers in the US from February 2014 to August 2018 and prospectively assessed longitudinal outcomes, with follow-up to 12 months postinjury. Participants were patients with msTBI (Glasgow Coma Scale scores 3-12) extracted from a larger group of patients with mild, moderate, or severe TBI who were enrolled in TRACK-TBI. Data analysis took place from October 2019 to April 2021.

Exposures

Moderate or severe TBI.

Main Outcomes and Measures

The Glasgow Outcome Scale-Extended (GOSE) and Disability Rating Scale (DRS) were used to assess global functional status 2 weeks and 3, 6, and 12 months postinjury. Scores on the GOSE were dichotomized to determine favorable (scores 4-8) vs unfavorable (scores 1-3) outcomes. Neurocognitive testing and patient reported outcomes at 12 months postinjury were analyzed.

Results

A total of 484 eligible patients were included from the 2679 individuals in the TRACK-TBI study. Participants with severe TBI (n = 362; 283 men [78.2%]; median [interquartile range] age, 35.5 [25-53] years) and moderate TBI (n = 122; 98 men [80.3%]; median [interquartile range] age, 38 [25-53] years) were comparable on demographic and premorbid variables. At 2 weeks postinjury, 36 of 290 participants with severe TBI (12.4%) and 38 of 93 participants with moderate TBI (41%) had favorable outcomes (GOSE scores 4-8); 301 of 322 in the severe TBI group (93.5%) and 81 of 103 in the moderate TBI group (78.6%) had moderate disability or worse on the DRS (total score ≥4). By 12 months postinjury, 142 of 271 with severe TBI (52.4%) and 54 of 72 with moderate TBI (75%) achieved favorable outcomes. Nearly 1 in 5 participants with severe TBI (52 of 270 [19.3%]) and 1 in 3 with moderate TBI (23 of 71 [32%]) reported no disability (DRS score 0) at 12 months. Among participants in a vegetative state at 2 weeks, 62 of 79 (78%) regained consciousness and 14 of 56 with available data (25%) regained orientation by 12 months.

Conclusions and Relevance

In this study, patients with msTBI frequently demonstrated major functional gains, including recovery of independence, between 2 weeks and 12 months postinjury. Severe impairment in the short term did not portend poor outcomes in a substantial minority of patients with msTBI. When discussing prognosis during the first 2 weeks after injury, clinicians should be particularly cautious about making early, definitive prognostic statements suggesting poor outcomes and withdrawal of life-sustaining treatment in patients with msTBI.

Pathological Computed Tomography Features Associated With Adverse Outcomes After Mild Traumatic Brain Injury: A TRACK-TBI Study With External Validation in CENTER-TBI

Question

Are different patterns of intracranial injury on head computed tomography associated with prognosis after mild traumatic brain injury (mTBI)?

Findings

In this cohort study, subarachnoid hemorrhage, subdural hematoma, and contusion often co-occurred and were associated with both incomplete recovery and more severe impairment out to 12 months after injury, while intraventricular and/or petechial hemorrhage co-occurred and were associated with more severe impairment up to 12 months after injury; epidural hematoma was associated with incomplete recovery at some points but not with more severe impairment. Some intracranial hemorrhage patterns were more strongly associated with outcomes than previously validated demographic and clinical variables.

Meaning

In this study, different pathological features on head computed tomography carried different implications for mild traumatic brain injury prognosis to 1 year.

Importance

A head computed tomography (CT) with positive results for acute intracranial hemorrhage is the gold-standard diagnostic biomarker for acute traumatic brain injury (TBI). In moderate to severe TBI (Glasgow Coma Scale [GCS] scores 3-12), some CT features have been shown to be associated with outcomes. In mild TBI (mTBI; GCS scores 13-15), distribution and co-occurrence of pathological CT features and their prognostic importance are not well understood.

Objective

To identify pathological CT features associated with adverse outcomes after mTBI.

Design, Setting, and Participants

The longitudinal, observational Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study enrolled patients with TBI, including those 17 years and older with GCS scores of 13 to 15 who presented to emergency departments at 18 US level 1 trauma centers between February 26, 2014, and August 8, 2018, and underwent head CT imaging within 24 hours of TBI. Evaluations of CT imaging used TBI Common Data Elements. Glasgow Outcome Scale–Extended (GOSE) scores were assessed at 2 weeks and 3, 6, and 12 months postinjury. External validation of results was performed via the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. Data analyses were completed from February 2020 to February 2021.

Exposures

Acute nonpenetrating head trauma.

Main Outcomes and Measures

Frequency, co-occurrence, and clustering of CT features; incomplete recovery (GOSE scores <8 vs 8); and an unfavorable outcome (GOSE scores <5 vs ≥5) at 2 weeks and 3, 6, and 12 months.

Results

In 1935 patients with mTBI (mean [SD] age, 41.5 [17.6] years; 1286 men [66.5%]) in the TRACK-TBI cohort and 2594 patients with mTBI (mean [SD] age, 51.8 [20.3] years; 1658 men [63.9%]) in an external validation cohort, hierarchical cluster analysis identified 3 major clusters of CT features: contusion, subarachnoid hemorrhage, and/or subdural hematoma; intraventricular and/or petechial hemorrhage; and epidural hematoma. Contusion, subarachnoid hemorrhage, and/or subdural hematoma features were associated with incomplete recovery (odds ratios [ORs] for GOSE scores <8 at 1 year: TRACK-TBI, 1.80 [95% CI, 1.39-2.33]; CENTER-TBI, 2.73 [95% CI, 2.18-3.41]) and greater degrees of unfavorable outcomes (ORs for GOSE scores <5 at 1 year: TRACK-TBI, 3.23 [95% CI, 1.59-6.58]; CENTER-TBI, 1.68 [95% CI, 1.13-2.49]) out to 12 months after injury, but epidural hematoma was not. Intraventricular and/or petechial hemorrhage was associated with greater degrees of unfavorable outcomes up to 12 months after injury (eg, OR for GOSE scores <5 at 1 year in TRACK-TBI: 3.47 [95% CI, 1.66-7.26]). Some CT features were more strongly associated with outcomes than previously validated variables (eg, ORs for GOSE scores <5 at 1 year in TRACK-TBI: neuropsychiatric history, 1.43 [95% CI .98-2.10] vs contusion, subarachnoid hemorrhage, and/or subdural hematoma, 3.23 [95% CI 1.59-6.58]). Findings were externally validated in 2594 patients with mTBI enrolled in the CENTER-TBI study.

Conclusions and Relevance

In this study, pathological CT features carried different prognostic implications after mTBI to 1 year postinjury. Some patterns of injury were associated with worse outcomes than others. These results support that patients with mTBI and these CT features need TBI-specific education and systematic follow-up.

Radiation Necrosis from Stereotactic Radiosurgery-How Do We Mitigate?

OPINION STATEMENT

Intracranial stereotactic radiosurgery (SRS) is an effective and convenient treatment for many brain conditions. Data regarding safety come mostly from retrospective single institutional studies and a small number of prospective studies. Variations in target delineation, treatment delivery, imaging follow-up protocols and dose prescription limit the interpretation of this data. There has been much clinical focus on radiation necrosis (RN) in particular, as it is being increasingly recognized on follow-up imaging. Symptomatic RN may be treated with medical therapy (such as corticosteroids and bevacizumab) with surgical resection being reserved for refractory patients. Nevertheless, RN remains a challenging condition to manage, and therefore upfront patient selection for SRS remains critical to provide complication-free control. Mitigation strategies need to be considered in situations where the baseline risk of RN is expected to be high-such as large target volume or re-irradiation. These may involve reduction in the prescribed dose or hypofractionated stereotactic radiation therapy (HSRT). Recently published guidelines and international meta-analysis report the benefit of HSRT in larger lesions, without compromising control rates. However, careful attention to planning parameters and SRS techniques still need to be adhered, even with HSRT. In cases where the risk is deemed to be high despite mitigation, a combination approach of surgery with or without post-operative radiation should be considered.

Economic Impact of COVID-19 on a High-Volume Academic Neurosurgical Practice

Background

Coronavirus disease-2019 (COVID-19) is a novel disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that rapidly spread around the globe. The dramatic increase in the number of cases and deaths have placed tremendous strain on health care systems worldwide. As health care workers and society adjust to focus treatment and prevention of COVID-19, other facets of the health care enterprise are affected, particularly surgical volume and revenue. The purpose of this study was to describe the financial impact of COVID-19 on an academic neurosurgery department.

Methods

A retrospective review of weekly average daily work relative value units (wRVUs) were compared before and after COVID-19 in the fiscal year 2020. A comparative time period of the same months in the year prior was also included for review. We also review strategies for triaging neurosurgical disease as needing emergent, urgent, or routine operative treatment.

Results

Daily average wRVU after COVID-19 dropped significantly with losses in all weeks examined. Of the 7 weeks in the current post-COVID period, the weekly daily average wRVU was 173 (range, 128–363). The mean decline was 51.4% compared with the pre-COVID era. Both inpatient and outpatient revenue was affected.

Conclusions

COVID-19 had a profound detrimental effect on surgical productivity and revenue generation.

A mixed-methods needs assessment of traumatic brain injury care in a low- and middle-income country setting: building neurocritical care capacity at two major hospitals in Cambodia

OBJECTIVE

The high global burden of traumatic brain injury (TBI) disproportionately affects low- and middle-income countries (LMICs). These settings also have the greatest disparity in the availability of surgical care in general and neurosurgical care in particular. Recent focus has been placed on alleviating this surgical disparity. However, most capacity assessments are purely quantitative, and few focus on concomitantly assessing the complex healthcare system needs required to care for these patients. The objective of the present study was to use both quantitative and qualitative assessment data to establish a comprehensive approach to inform capacity-development initiatives for TBI care at two hospitals in an LMIC, Cambodia.

METHODS

This mixed-methods study used 3 quantitative assessment tools: the World Health Organization Personnel, Infrastructure, Procedures, Equipment, Supplies (WHO PIPES) checklist, the neurosurgery-specific PIPES (NeuroPIPES) checklist, and the Neurocritical Care (NCC) checklist at two hospitals in Phnom Penh, Cambodia. Descriptive statistics were obtained for quantitative results. Qualitative semistructured interviews of physicians, nurses, and healthcare administrators were conducted by a single interviewer. Responses were analyzed using a thematic content analysis approach and coded to allow categorization under the PIPES framework.

RESULTS

Of 35 healthcare providers approached, 29 (82.9%) participated in the surveys, including 19 physicians (65.5%) and 10 nurses (34.5%). The majority had fewer than 5 years of experience (51.7%), were male (n = 26, 89.7%), and were younger than 40 years of age (n = 25, 86.2%). For both hospitals, WHO PIPES scores were lowest in the equipment category. However, using the NCC checklist, both hospitals scored higher in equipment (81.2% and 62.7%) and infrastructure (78.6% and 69.6%; hospital 1 and 2, respectively) categories and lowest in the training/continuing education category (41.7% and 33.3%, hospital 1 and 2, respectively). Using the PIPES framework, analysis of the qualitative data obtained from interviews revealed a need for continuing educational initiatives for staff, increased surgical and critical care supplies and equipment, and infrastructure development. The analysis further elucidated barriers to care, such as challenges with time availability for experienced providers to educate incoming healthcare professionals, issues surrounding prehospital care, maintenance of donated supplies, and patient poverty.

CONCLUSIONS

This mixed-methods study identified areas in supplies, equipment, and educational/training initiatives as areas for capacity development for TBI care in an LMIC such as Cambodia. This first application of the NCC checklist in an LMIC setting demonstrated limitations in its use in this setting. Concomitant qualitative assessments provided insight into barriers otherwise undetected in quantitative assessments.

Time-Resolved MRI Assessment of Convection-Enhanced Delivery by Targeted and Nontargeted Nanoparticles in a Human Glioblastoma Mouse Model

Convection-enhanced delivery (CED) provides direct access of infusates to brain tumors; however, clinical translation of this technology has not been realized because of the inability to accurately visualize infusates in real-time and lack of targeting modalities against diffuse cancer cells. In this study, we use time-resolved MRI to reveal the kinetics of CED processes in a glioblastoma (GBM) model using iron oxide nanoparticles (NP) modified with a glioma-targeting ligand, chlorotoxin (CTX). Mice bearing orthotopic human GBM tumors were administered a single dose of targeted CTX-conjugated NP (NPCP-CTX) or nontargeted NP (NPCP) via CED. High-resolution T2-weighted, T2*-weighted, and quantitative T2 MRI were utilized to image NP delivery in real time and determined the volume of distribution (VD) of NPs at multiple time points over the first 48 hours post-CED. GBM-specific targeting was evaluated by flow cytometry and intracellular NP localization by histologic assessment. NPCP-CTX produced a VD of 121 ± 39 mm3 at 24 hours, a significant increase compared with NPCP, while exhibiting GBM specificity and localization to cell nuclei. Notably, CED of NPCP-CTX resulted in a sustained expansion of VD well after infusion, suggesting a possible active transport mechanism, which was further supported by the presence of NPs in endothelial and red blood cells. In summary, we show that time-resolved MRI is a suitable modality to study CED kinetics, and CTX-mediated CED facilitates extensive distribution of infusate and specific targeting of tumor cells. SIGNIFICANCE: MRI is used to monitor convection-enhanced delivery in real time using a nanoparticle-based contrast agent, and glioma-specific targeting significantly improves the volume of distribution in tumors.

Recovery After Mild Traumatic Brain Injury in Patients Presenting to US Level I Trauma Centers: A Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) Study

Importance

Most traumatic brain injuries (TBIs) are classified as mild (mTBI) based on admission Glasgow Coma Scale (GCS) scores of 13 to 15. The prevalence of persistent functional limitations for these patients is unclear.

Objectives

To characterize the natural history of recovery of daily function following mTBI vs peripheral orthopedic traumatic injury in the first 12 months postinjury using data from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study, and, using clinical computed tomographic (CT) scans, examine whether the presence (CT+) or absence (CT-) of acute intracranial findings in the mTBI group was associated with outcomes.

Design, Setting, and Participants

TRACK-TBI, a cohort study of patients with mTBI presenting to US level I trauma centers, enrolled patients from February 26, 2014, to August 8, 2018, and followed up for 12 months. A total of 1453 patients at 11 level I trauma center emergency departments or inpatient units met inclusion criteria (ie, mTBI [n = 1154] or peripheral orthopedic traumatic injury [n = 299]) and were enrolled within 24 hours of injury; mTBI participants had admission GCS scores of 13 to 15 and clinical head CT scans. Patients with peripheral orthopedic trauma injury served as the control (OTC) group.

Exposures

Participants with mTBI or OTC.

Main Outcomes and Measures

The Glasgow Outcome Scale Extended (GOSE) scale score, reflecting injury-related functional limitations across broad life domains at 2 weeks and 3, 6, and 12 months postinjury was the primary outcome. The possible score range of the GOSE score is 1 (dead) to 8 (upper good recovery), with a score less than 8 indicating some degree of functional impairment.

Results

Of the 1453 participants, 953 (65.6%) were men; mean (SD) age was 40.9 (17.1) years in the mTBI group and 40.9 (15.4) years in the OTC group. Most participants (mTBI, 87%; OTC, 93%) reported functional limitations (GOSE <8) at 2 weeks postinjury. At 12 months, the percentage of mTBI participants reporting functional limitations was 53% (95% CI, 49%-56%) vs 38% (95% CI, 30%-45%) for OTCs. A higher percentage of CT+ patients reported impairment (61%) compared with the mTBI CT- group (49%; relative risk [RR], 1.24; 95% CI, 1.08-1.43) and a higher percentage in the mTBI CT-group compared with the OTC group (RR, 1.28; 95% CI, 1.02-1.60).

Conclusions and Relevance

Most patients with mTBI presenting to US level I trauma centers report persistent, injury-related life difficulties at 1 year postinjury, suggesting the need for more systematic follow-up of patients with mTBI to provide treatments and reduce the risk of chronic problems after mTBI.

Risk of Posttraumatic Stress Disorder and Major Depression in Civilian Patients After Mild Traumatic Brain Injury: A TRACK-TBI Study

IMPORTANCE

Traumatic brain injury (TBI) has been associated with adverse mental health outcomes, such as posttraumatic stress disorder (PTSD) and major depressive disorder (MDD), but little is known about factors that modify risk for these psychiatric sequelae, particularly in the civilian sector.

OBJECTIVE

To ascertain prevalence of and risk factors for PTSD and MDD among patients evaluated in the emergency department for mild TBI (mTBI).

DESIGN, SETTING, AND PARTICIPANTS

Prospective longitudinal cohort study (February 2014 to May 2018). Posttraumatic stress disorder and MDD symptoms were assessed using the PTSD Checklist for DSM-5 and the Patient Health Questionnaire-9 Item. Risk factors evaluated included preinjury and injury characteristics. Propensity score weights-adjusted multivariable logistic regression models were performed to assess associations with PTSD and MDD. A total of 1155 patients with mTBI (Glasgow Coma Scale score, 13-15) and 230 patients with nonhead orthopedic trauma injuries 17 years and older seen in 11 US hospitals with level 1 trauma centers were included in this study.

MAIN OUTCOMES AND MEASURES

Probable PTSD (PTSD Checklist for DSM-5 score, ≥33) and MDD (Patient Health Questionnaire-9 Item score, ≥15) at 3, 6, and 12 months postinjury.

RESULTS

Participants were 1155 patients (752 men [65.1%]; mean [SD] age, 40.5 [17.2] years) with mTBI and 230 patients (155 men [67.4%]; mean [SD] age, 40.4 [15.6] years) with nonhead orthopedic trauma injuries. Weights-adjusted prevalence of PTSD and/or MDD in the mTBI vs orthopedic trauma comparison groups at 3 months was 20.0% (SE, 1.4%) vs 8.7% (SE, 2.2%) (P < .001) and at 6 months was 21.2% (SE, 1.5%) vs 12.1% (SE, 3.2%) (P = .03). Risk factors for probable PTSD at 6 months after mTBI included less education (adjusted odds ratio, 0.89; 95% CI, 0.82-0.97 per year), being black (adjusted odds ratio, 5.11; 95% CI, 2.89-9.05), self-reported psychiatric history (adjusted odds ratio, 3.57; 95% CI, 2.09-6.09), and injury resulting from assault or other violence (adjusted odds ratio, 3.43; 95% CI, 1.56-7.54). Risk factors for probable MDD after mTBI were similar with the exception that cause of injury was not associated with increased risk.

CONCLUSIONS AND RELEVANCE

After mTBI, some individuals, on the basis of education, race/ethnicity, history of mental health problems, and cause of injury were at substantially increased risk of PTSD and/or MDD. These findings should influence recognition of at-risk individuals and inform efforts at surveillance, follow-up, and intervention.

What are the critical elements of sideline screening that can be used to establish the diagnosis of concussion? A systematic review

BACKGROUND

Sideline detection is the first and most significant step in recognising a potential concussion and removing an athlete from harm. This systematic review aims to evaluate the critical elements aiding sideline recognition of potential concussions including screening tools, technologies and integrated assessment protocols.

DATA SOURCES

Bibliographic databases, grey literature repositories and relevant websites were searched from 1 January 2000 to 30 September 2016. A total of 3562 articles were identified.

STUDY SELECTION

Original research studies evaluating a sideline tool, technology or protocol for sports-related concussion were eligible, of which 27 studies were included.

DATA EXTRACTION

A standardised form was used to record information. The QUADAS-2 and Newcastle-Ottawa tools were used to rate risk of bias. Strength of evidence was assessed using the Grades of Recommendation, Assessment, Development and Evaluation Working Group system.

DATA SYNTHESIS

Studies assessing symptoms, the King-Devick test and multimodal assessments reported high sensitivity and specificity. Evaluations of balance and cognitive tests described lower sensitivity but higher specificity. However, these studies were at high risk of bias and the overall strength of evidence examining sideline screening tools was very low. A strong body of evidence demonstrated that head impact sensors did not provide useful sideline concussion information. Low-strength evidence suggested a multimodal, multitime-based concussion evaluation process incorporating video review was important in the recognition of significant head impact events and delayed onset concussion.

CONCLUSION

In the absence of definitive evidence confirming the diagnostic accuracy of sideline screening tests, consensus-derived multimodal assessment tools, such as the Sports Concussion Assessment Tool, are recommended. Sideline video review may improve recognition and removal from play of athletes who have sustained significant head impact events. Current evidence does not support the use of impact sensor systems for real-time concussion identification.

Neurological and spinal manifestations of the Ehlers-Danlos syndromes

The Ehlers-Danlos syndromes (EDS) are a heterogeneous group of heritable connective tissue disorders characterized by joint hypermobility, skin extensibility, and tissue fragility. This communication briefly reports upon the neurological manifestations that arise including the weakness of the ligaments of the craniocervical junction and spine, early disc degeneration, and the weakness of the epineurium and perineurium surrounding peripheral nerves. Entrapment, deformation, and biophysical deformative stresses exerted upon the nervous system may alter gene expression, neuronal function and phenotypic expression. This report also discusses increased prevalence of migraine, idiopathic intracranial hypertension, Tarlov cysts, tethered cord syndrome, and dystonia, where associations with EDS have been anecdotally reported, but where epidemiological evidence is not yet available. Chiari Malformation Type I (CMI) has been reported to be a comorbid condition to EDS, and may be complicated by craniocervical instability or basilar invagination. Motor delay, headache, and quadriparesis have been attributed to ligamentous laxity and instability at the atlanto-occipital and atlantoaxial joints, which may complicate all forms of EDS. Discopathy and early degenerative spondylotic disease manifest by spinal segmental instability and kyphosis, rendering EDS patients prone to mechanical pain, and myelopathy. Musculoskeletal pain starts early, is chronic and debilitating, and the neuromuscular disease of EDS manifests symptomatically with weakness, myalgia, easy fatigability, limited walking, reduction of vibration sense, and mild impairment of mobility and daily activities. Consensus criteria and clinical practice guidelines, based upon stronger epidemiological and pathophysiological evidence, are needed to refine diagnosis and treatment of the various neurological and spinal manifestations of EDS. © 2017 Wiley Periodicals, Inc.

Statements of Agreement From the Targeted Evaluation and Active Management (TEAM) Approaches to Treating Concussion Meeting Held in Pittsburgh, October 15-16, 2015

BACKGROUND

Conventional management for concussion involves prescribed rest and progressive return to activity. Recent evidence challenges this notion and suggests that active approaches may be effective for some patients. Previous concussion consensus statements provide limited guidance regarding active treatment.

OBJECTIVE

To describe the current landscape of treatment for concussion and to provide summary agreements related to treatment to assist clinicians in the treatment of concussion.

METHODS

On October 14 to 16, 2015, the Targeted Evaluation and Active Management (TEAM) Approaches to Treating Concussion meeting was convened in Pittsburgh, Pennsylvania. Thirty-seven concussion experts from neuropsychology, neurology, neurosurgery, sports medicine, physical medicine and rehabilitation, physical therapy, athletic training, and research and 12 individuals representing sport, military, and public health organizations attended the meeting. The 37 experts indicated their agreement on a series of statements using an audience response system clicker device.

RESULTS

A total of 16 statements of agreement were supported covering (1) Summary of the Current Approach to Treating Concussion, (2) Heterogeneity and Evolving Clinical Profiles of Concussion, (3) TEAM Approach to Concussion Treatment: Specific Strategies, and (4) Future Directions: A Call to Research. Support (ie, response of agree or somewhat agree) for the statements ranged from to 97% to 100%.

CONCLUSION

Concussions are characterized by diverse symptoms and impairments and evolving clinical profiles; recovery varies on the basis of modifying factors, injury severity, and treatments. Active and targeted treatments may enhance recovery after concussion. Research is needed on concussion clinical profiles, biomarkers, and the effectiveness and timing of treatments.

ABBREVIATIONS

ARS, audience response systemCDC, Centers for Disease Control and PreventionDoD, Department of DefensemTBI, mild traumatic brain injuryNCAA, National Collegiate Athletic AssociationNFL, National Football LeagueNIH, National Institutes of HealthRCT, randomized controlled trialRTP, return to playSRC, sport- and recreation-related concussionTBI, traumatic brain injuryTEAM, Targeted Evaluation and Active Management.

Increased cerebrospinal fluid cleaved tau protein (C-tau) levels suggest axonal damage in pediatric patients with brain tumors

OBJECTIVE

This study aims to determine if cerebrospinal fluid/serum cleaved tau protein and CSF 9-hydroxyoctadecadienoic acid levels, reflecting potential biomarkers of overall neuronal injury and lipid peroxidation, respectively, are elevated in brain tumor patients compared with controls.

DESIGN

This article is a prospective clinical observational study.

SETTING

This study is conducted at a tertiary-care children's hospital.

PATIENTS

Our participants are children younger than or equal to 18 years of age undergoing brain tumor surgery.

MEASUREMENTS AND MAIN RESULTS

During the study period, 26 consecutive patients newly diagnosed with brain tumors who met the inclusion criteria were prospectively enrolled. Baseline cerebrospinal fluid analysis of cleaved tau and 9-hydroxyoctadecadienoic acid were measured in 15 patients. Cerebrospinal fluid cleaved tau and 9-hydroxyoctadecadienoic acid levels were measured in 22 patients for post-surgery days 1 and 3. Serum cleaved tau levels were measured for 20 and 18 patients for post-surgery days 1 and 3, respectively. The presence of a brain tumor significantly increased the baseline cerebrospinal fluid cleaved tau levels but did not affect cerebrospinal fluid 9-hydroxyoctadecadienoic acid levels. Similarly, there was a significant increase in post-surgery day 1 cerebrospinal fluid cleaved tau levels from baseline (p = 0.01) and a trend toward significant decrease in post-surgery day 3 cerebrospinal fluid cleaved tau from day 1 (p = 0.07). 9-Hydroxyoctadecadienoic acid concentrations remained relatively constant over time with no differences noted between the control and brain tumor patients. There was a trend towards a significant association between cerebrospinal fluid cleaved tau levels and duration of symptoms (p = 0.07).

CONCLUSIONS

Cerebrospinal fluid cleaved tau levels in children with newly diagnosed brain tumors exhibit markedly elevated cerebrospinal fluid cleaved tau levels, suggesting axonal damage. This axonal injury does not seem to correlate with lipid peroxidation at least when as assessed by cerebrospinal fluid 9-hydroxyoctadecadienoic acid levels. There was no association found between the biomarkers and multiple independent variables obtained at pre- and post-tumor resection.

Rapid sequence magnetic resonance imaging in the assessment of children with hydrocephalus

OBJECTIVE

Recent reports have shown the utility of rapid-acquisition magnetic resonance imaging (MRI) in the evaluation of children with hydrocephalus. Rapid sequence MRI (RS-MRI) acquires clinically useful images in seconds without exposing children to the risks of ionizing radiation or sedation. We review our experience with RS-MRI in children with shunts.

METHODS

Overall image quality, cost, catheter visualization, motion artifact, and ventricular size were reviewed for all RS-MRI studies obtained at Seattle Children's Hospital during a 2-year period. Image acquisition time was 12-19 seconds, with sessions usually lasting less than 3 minutes.

RESULTS

Image quality was very good or excellent in 94% of studies, whereas only one was graded as poor. Significant motion artifact was noted in 7%, whereas 77% had little or no motion artifact. Catheter visualization was good or excellent in 57%, poor in 36%, and misleading in 7%. Small ventricular size was correlated with poor catheter visualization (Spearman's ρ = 0.586; P < 0.00001). RS-MRI imaging cost ∼$650 more than conventional computed tomography (CT).

CONCLUSIONS

Our study supports that RS-MRI is an adequate substitute that allows reduced use of CT imaging and resultant exposure to ionizing radiation. Catheter position visualization remains suboptimal when ventricles are small, but shunt malfunction can be adequately determined in most cases. The cost is significantly more than CT, but the potential for lifetime reduction in radiation exposure may justify this expense in children. Limitations include the risk of valve malfunction after repeated exposure to high magnetic fields and the need for reprogramming with many types of adjustable valves.

Rapid pharmacokinetic and biodistribution studies using cholorotoxin-conjugated iron oxide nanoparticles: a novel non-radioactive method

Background

Recent advances in nanotechnology have led to the development of biocompatible nanoparticles for in vivo molecular imaging and targeted therapy. Many nanoparticles have undesirable tissue distribution or unacceptably low serum half-lives. Pharmacokinetic (PK) and biodistribution studies can help inform decisions determining particle size, coatings, or other features early in nanoparticle development. Unfortunately, these studies are rarely done in a timely fashion because many nanotechnology labs lack the resources and expertise to synthesize radioactive nanoparticles and evaluate them in mice.

Methodology/Principal Findings

To address this problem, we developed an economical, radioactivity-free method for assessing serum half-life and tissue distribution of nanoparticles in mice. Iron oxide nanoparticles coated with chitosan and polyethylene glycol that utilize chlorotoxin as a targeting molecule have a serum half-life of 7–8 hours and the particles remain stable for extended periods of time in physiologic fluids and in vivo. Nanoparticles preferentially distribute to spleen and liver, presumably due to reticuloendothelial uptake. Other organs have very low levels of nanoparticles, which is ideal for imaging most cancers in the future. No acute toxicity was attributed to the nanoparticles.

Conclusions/Significance

We report here a simple near-infrared fluorescence based methodology to assess PK properties of nanoparticles in order to integrate pharmacokinetic data into early nanoparticle design and synthesis. The nanoparticles tested demonstrate properties that are excellent for future clinical imaging strategies and potentially suitable for targeted therapy.

Feeder-free self-renewal of human embryonic stem cells in 3D porous natural polymer scaffolds

Human embryonic stem cells (hESCs) are routinely cultured on fibroblast feeder layers or in fibroblast-conditioned medium, which requires continued supply of feeder cells and poses the risks of xenogenic contamination and other complications such as feeder-dependent outcome. Here, we demonstrate a strategy that supports sustained self-renewal of hESCs in a three-dimensional porous natural polymer scaffold, comprised of chitosan and alginate, without the support of feeder cells or conditioned medium. We assessed the pluripotency of the renewed hESCs both in vitro by evaluation of cellular proliferation, functionality, and gene activities for 21 days, and in vivo by implantation of the stem cell populated scaffolds in an immunodeficient mouse model to induce teratoma formation. The self-renewed stem cells can be easily recovered for subculture by decomposing the scaffold under a mild condition. We further subcultured recovered hESCs for 14 days and verified their pluripotency. In addition to providing a clean environment for stem cell renewal, this strategy, with the demonstrated biocompatibility and biodegradability of chitosan and alginate, may potentially allow for the direct implantation of stem cell populated scaffolds for a broad spectrum of applications in tissue engineering and regenerative medicine.

Neurointensive care; impaired cerebral autoregulation in infants and young children early after inflicted traumatic brain injury: a preliminary report

The objective of this report is to describe cerebral autoregulation after severe inflicted pediatric traumatic brain injury (iTBI). We examined cerebral autoregulation of both cerebral hemispheres (mean autoregulatory index; ARI) in children <5 years with Glasgow Coma Scale (GCS) score of <9 and no evidence of brain death within the first 48 h of pediatric intensive care unit (PICU) admission. Discharge and 6-month Glasgow Outcome Scale (GOS) scores were collected. GOS of <4 reflected poor outcome. All three iTBI and all seven noninflicted TBI (nTBI) patients had admission GCS score of <9. Eight of 10 patients had Autoregulatory Index (ARI) of <0.4 (impaired cerebral autoregulation) of at least one hemisphere. All children with iTBI had poor outcome, and none had intact cerebral autoregulation in both hemispheres. Children with nTBI had better overall outcome than those with iTBI. Two of the children with nTBI had intact autoregulation in both hemispheres and good outcome. Two of the three children with iTBI had differential effects on autoregulation between hemispheres despite bilateral injury. These are, to our knowledge, the first data on cerebral blood flow autoregulation in the unique setting of iTBI and provide a rationale for further study of their relationship to outcome and effects of therapy.

Phenotypic definition of Chiari type I malformation coupled with high-density SNP genome screen shows significant evidence for linkage to regions on chromosomes 9 and 15

Chiari type I malformation (CMI; OMIM 118420) is narrowly defined when the tonsils of the cerebellum extend below the foramen magnum, leading to a variety of neurological symptoms. It is widely thought that a small posterior fossa (PF) volume, relative to the total cranial volume leads to a cramped cerebellum and herniation of the tonsils into the top of the spinal column. In a collection of magnetic resonance imagings (MRIs) from affected individuals and their family members, we measured correlations between ten cranial morphologies and estimated their heritability in these families. Correlations between bones delineating the PF and significant heritability of PF volume (0.955, P = 0.003) support the cramped PF theory and a genetic basis for this condition. In a collection of 23 families with 71 affected individuals, we performed a genome wide linkage screen of over 10,000 SNPs across the genome to identify regions of linkage to CMI. Two-point LOD scores on chromosome 15 reached 3.3 and multipoint scores in this region identified a 13 cM region with LOD scores over 1 (15q21.1-22.3). This region contains a biologically plausible gene for CMI, fibrillin-1, which is a major gene in Marfan syndrome and has been linked to Shprintzen-Goldberg syndrome, of which CMI is a distinguishing characteristic. Multipoint LOD scores on chromosome 9 maximized at 3.05, identifying a 40 cM region with LOD scores over 1 (9q21.33-33.1) and a tighter region with multipoint LOD scores over 2 that was only 8.5 cM. This linkage evidence supports a genetic role in Chiari malformation and justifies further exploration with fine mapping and investigation of candidate genes in these regions.

Optical and MRI multifunctional nanoprobe for targeting gliomas

A multifunctional nanoprobe capable of targeting glioma cells, detectable by both magnetic resonance imaging and fluorescence microscopy, was developed. The nanoprobe was synthesized by coating iron oxide nanoparticles with covalently bound bifunctional poly(ethylene glycol) (PEG) polymer, which were subsequently functionalized with chlorotoxin and the near-infrared fluorescing molecule Cy5.5. Both MR imaging and fluorescence microscopy showed significant preferential uptake of the nanoparticle conjugates by glioma cells. Such a nanoprobe could potentially be used to image resections of glioma brain tumors in real time and to correlate preoperative diagnostic images with intraoperative pathology at cellular-level resolution.

Aneurysmal Bone Cyst of the Atlas: Successful Treatment through Selective Arterial Embolization: Case Report

OBJECTIVE AND IMPORTANCE:

Aneurysmal bone cysts (ABCs) are benign and expansile osteolytic lesions that can occur in any location in the spine, including the craniovertebral junction. Aggressive resection followed by bone grafting has been the mainstay of treatment, with selective arterial embolization as a presurgical adjunct. Complete excision of these lesions at the craniovertebral junction is associated with high surgical morbidity. We report a case of successful treatment of an ABC of the atlas in a child with selective arterial embolization alone.

CLINICAL PRESENTATION:

A 10-year-old girl presented with persistent neck pain after a snowboarding accident. Computed tomography and magnetic resonance imaging of the cervical spine revealed an expansile cystic mass involving the right lateral mass of C1. Digital subtraction angiography revealed a tumor blush, which, along with the cystic appearance of the lesion, was consistent with an ABC.

INTERVENTION:

The arterial feeders to the lesion were selectively embolized with polyvinyl alcohol particles. Three sessions of embolization were required to eradicate the blood supply to the lesion completely.

CONCLUSION:

Complete surgical resection of ABCs at the craniovertebral junction can be associated with high morbidity secondary to the highly vascular and destructive nature of these lesions. The case discussed here demonstrates the viability of selective arterial embolization as a primary and stand-alone modality of treatment.

Progressive postnatal craniosynostosis and increased intracranial pressure

Since its first description by Virchow in 1851, craniosynostosis has been known as a potentially serious condition resulting in premature fusion of skull sutures. Traditionally, craniosynostosis has been regarded as an event that occurs early in fetal development, resulting in a skull shape at birth that is determined by the suture or sutures involved. In recent years, a different form of craniosynostosis has been observed. Patients initially come to the attention of physicians because they exhibit midface hypoplasia or occasionally hypertelorism. The affected individuals all have a normal skull shape and open sutures in infancy but develop multiple-suture craniosynostosis postnatally, ultimately requiring surgical correction. These cases are significant because, although the patients do not initially display the physical manifestations of craniosynostosis, they frequently develop increased intracranial pressure, which can have devastating consequences. Unless these patients are recognized and vigilant follow-up monitoring is instituted at an early age, permanent impairment can result. A retrospective chart review study was conducted, and patients with multiple-suture craniosynostosis who developed symptoms of increased intracranial pressure were selected. The patients were divided into two groups, namely, those with normal sutures and/or head shape at birth (progressive craniosynostosis) (n = 15) and those with abnormal head shapes at birth (classic syndromic craniosynostosis) (n = 12). Clinical and radiological findings typically used to monitor the development of increased intracranial pressure were reviewed for both groups and compared. In addition, mutational analyses were performed. All patients with progressive postnatal craniosynostosis demonstrated clinical, radiological, or ophthalmological evidence of increased intracranial pressure, requiring skull expansion. Those patients displayed papilledema, anterior fontanelle bulge, and thumbprinting more often than did the patients with classic craniosynostosis. Thirteen of 15 patients were given the clinical diagnosis of Crouzon syndrome, which raises the question of whether such patients represent a subset of patients with this syndrome. Mutational analyses for the patients with progressive craniosynostosis demonstrated that, of 13 patients tested, 11 had mutations in exon 7 or 9 of FGFR2, which is a common site of mutations in Crouzon syndrome. The traditional indications of increased intracranial pressure used to monitor patients with classic craniosynostosis can be used to monitor patients with progressive postnatal craniosynostosis, particularly anterior fontanelle bulge, papilledema, and thumbprinting. It is thought that regular monitoring of these characteristics may lead to earlier diagnosis and allow for surgical intervention before the development of undesirable outcomes. It is important for clinicians to be aware of this group of patients, because any delay in diagnosis and treatment can result in severe consequences for the patients.

Transcoronal brow lift fixation: a 2-point dermis-to-skull fibrous scar adhesion

The authors prefer an open approach to brow lift involving a completely autogenous fixation method. They contend that scarring produced by electrocautery "checkerboarding" of the frontalis and periosteum results in adhesion of the forehead dermis and soft tissues to the frontal cranium.

Zafirlukast (Accolate): A new treatment for capsular contracture

BACKGROUND

Capsular contracture after breast augmentation or reconstructive breast surgery is a difficult problem. Previous studies have suggested that alteration of the inflammatory response could have a role in reducing the incidence of capsular contracture.

OBJECTIVE

We report a series of patients with Baker class III or IV capsular contracture who underwent treatment with zafirlukast.

METHODS

Patients received a regimen of zafirlukast 20 mg by mouth 2 times daily for 3 months.

RESULTS

In many cases, dramatic softening of the breast capsule was evident after 1 to 3 months of treatment.

CONCLUSIONS

Zafirlukast appears to effectively soften early capsular contracture and may prevent the formation of capsular contracture in those patients at risk. (Aesthetic Surg J 2002;22:329-336.).

Nostrilplasty: raising, lowering, widening, and symmetry correction of the alar rim

BACKGROUND

Although the alar rim has frequently been neglected in correction of nasal deformities, techniques for its improvement have been proposed and used successfully.

OBJECTIVE

Two techniques for correction of the deformed alar rim are described.

METHODS

To lower the alar rim, the internal skin of the vestibule is dissected away from the areolar tissue and brought down as a flap. A segment of cartilage is taken from the septum or upper portion of the lower lateral cartilage. The cartilage graft is placed in the rim and the vestibular mucosa is folded over the graft and sutured to hold the cartilage in place. Raising of the alar rim is accomplished through direct excision to raise the rim and to make the nostril longer or wider. This technique is applicable to correction of a dropped rim, pinched nostrils, hidden columella, sigmoid ala, small nostrils, and foreshortened nose.

RESULTS

These techniques have been used to treat primary, secondary, and traumatic nasal deformities in more than 200 patients during the past 20 years with few complications.

CONCLUSIONS

Although the techniques described require a learning curve, once mastered they can be combined with other techniques used routinely in rhinoplasty to successfully treat a variety of nasal deformities. (Aesthetic Surg J 2002;22:227-237.).

Triage for the neurosurgeon

Triage for the neurosurgeon is a misnomer. The neurosurgeon's role within a mass-casualty situation is one of a subspecialist surgeon instead of a triage officer. Unfortunately because of the events of September 11, 2001, civilian neurosurgeons and other medical specialists have been questioning their role within a mass-casualty situation or, worse, a situation created by biological, chemical, or nuclear weapons. There is no single triage system used exclusively within the United States, and different systems have differing sensitivities, specificities, and labeling methods. The purpose of this article is to discuss varying aspects of triage for both military personnel and civilians and suggest how the neurosurgeon may help shape this process within his or her community. Furthermore, the effects of biological, chemical, and nuclear weapons will be discussed in relation to the triage system.