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Thalamic gliomas are rare. The natural history is unpredictable, and the optimal management of these tumors in children is poorly defined. The aim was to identify outcomes, prognostic factors, and response to various modalities of treatment in a relatively large population of pediatric thalamic tumors from many centers within a fairly homogeneous health care system. We performed a Canadian multicenter retrospective review of pediatric thalamic tumors presenting during the MRI era (1989–2012). Radiology and pathology were reviewed by central independent reviewers. Paraffin shavings for RNA extraction were taken and tested for fusion events involving KIAA1549:BRAF. Tumors were classified as unilateral or bithalamic based on their origin on imaging. Univariate and multivariate analyses on factors influencing survival were performed. Seventy-two thalamic tumors were identified from 11 institutions. Females represented 53 % of the study population, and the mean age at presentation was 8.9 years. Sixty-two tumors were unilateral and 10 bithalamic. Unilateral tumors had a greater propensity to grow inferiorly towards the brainstem. These tumors were predominantly low grade in comparison to bithalamic tumors which were high-grade astrocytomas. The 5-year overall survival was 61 ± 13 % for unithalamic tumors compared to 37 ± 32 % for bithalamic tumors (p = 0.097). Multivariate analysis indicated tumor grade as the only significant prognostic factor for unithalamic tumors. Six unilateral tumors, all low grade, were BRAF fusion positive. Unilateral and bilateral thalamic tumors behave differently. Surgical resection is an appropriate treatment option in unilateral tumors, most of which are low grade, but outcome is not related to extent of resection (EOR). Bilateral thalamic tumors have a poorer prognosis, but the occasional patient does remarkably well. The efficacy of chemotherapy and radiotherapy has not been clearly demonstrated. Novel therapeutic approaches are required to improve the prognosis for malignant unilateral thalamic tumors and bilateral thalamic tumors.

Introduction Advances in perinatal care in the developed world have resulted in more children living into adulthood with complex chronic health conditions. Transition is a process to improve and maximize the functional status of adolescents via the provision of adequate and appropriate health services in adulthood. This process is frequently disjointed, fragmented and inconsistent and inadequate transition increases morbidity, hospital admissions and urgent interventions. Ten thousand children are diagnosed with hydrocephalus annually in North America. Most survive to adulthood yet there are few transitioning programs and little research data on successful programs for this population. Methods An email survey of paediatric neurosurgical centres in Canada was carried out to establish current transition practices and attitudes for adolescents with hydrocephalus. Data were analyzed descriptively. Results Eleven out of 12 centres responded. The age of transition ranged from 16 to 18 years. Four centres have access to a dedicated Adult Hydrocephalus Clinic. Referral practices vary between centres and we highlight inconsistencies in care to this cohort of patients in Canada. There is little satisfaction among neurosurgeons with current transition arrangements in Canada. Several suggestions were made on how to improve this process. Conclusion We recommend research into the needs of patients with hydrocephalus in order to formalize appropriate standards for transitioning patients with a view to developing national guidelines to standardize the transition process. This will require input from patients, families and the wider medical and allied health professional groups.

Kellmeyer and colleagues, on behalf of the International Neuroethics Society (INS) Emerging Issues Taskforce (2019) discuss the current and future environment for neuroethics on this, the 15th anni...

OBJECT The goal in this review was to summarize the results of clinical neuroimaging studies performed in patients with sports-related concussion (SRC) who were referred to a multidisciplinar ypediatric concussion program. METHODS The authors conducted a retrospective review of medical records and neuroimaging findings for all patients referred to a multidisciplinary pediatric concussion program between September 2013 and July 2014. Inclusion criteria were as follows: 1) age ≤ 19 years; and 2) physician-diagnosed SRC. All patients underwent evaluation and follow-up by the same neurosurgeon. The 2 outcomes examined in this review were the frequency of neuroimaging studies performed in this population (including CT and MRI) and the findings of those studies. Clinical indications for neuroimaging and the impact of neuroimaging findings on clinical decision making were summarized where available. This investigation was approved by the local institutional ethics review board. RESULTS A total of 151 patients (mean age 14 years, 59% female) were included this study. Overall, 36 patients (24%) underwent neuroimaging studies, the results of which were normal in 78% of cases. Sixteen percent of patients underwent CT imaging; results were normal in 79% of cases. Abnormal CT findings included the following: arachnoid cyst (1 patient), skull fracture (2 patients), suspected intracranial hemorrhage (1 patient), and suspected hemorrhage into an arachnoid cyst (1 patient). Eleven percent of patients underwent MRI; results were normal in 75% of cases. Abnormal MRI findings included the following: intraparenchymal hemorrhage and sylvian fissure arachnoid cyst (1 patient); nonhemorrhagic contusion (1 patient); demyelinating disease (1 patient); and posterior fossa arachnoid cyst, cerebellar volume loss, and nonspecific white matter changes (1 patient). CONCLUSIONS Results of clinical neuroimaging studies are normal in the majority of pediatric patients with SRC. However, in selected cases neuroimaging can provide information that impacts decision making about return to play and retirement from the sport.

Our goal is to describe a case of hydrocephalus in the setting of a Yasargil Type IV-C secondary vein of Galen malformation (VGM), treated with a combined endscopic and endovascular approach. We retrospectively reviewed the records of a patient admitted to the neurosurgical department hydrocephalus related to a secondary VGM. A 47 year old male, presents with 8 months of progressive headaches and gait ataxia. Imaging displays a triventricular hydrocephalus, a tectal AVM, and an aneurysmal dilation of the great vein of Galen. Angiography displays a tectal AVM supplied by bilateral posterior choroidals with drainage into the vein of Galen. In addition there were direct high-flow arteriovenous fistulas into the vein of Galen via meningeal feeders. The diagnosis of a Yasargil Type IV-C secondary VGM was made. The patient was treated via a combined endoscopic and endovascular approach. An endoscopic third ventriculostomy (ETV) was conducted for his hydrocephalus. He subsequently underwent a partial endovascular embolization of the left tentorial arterial feeder 1.5 months after his ETV. Post-operatively his hydrocephalus resolved, and his complex secondary VGM completely obliterated after a single partial embolization. Secondary VGMs with associated high-flow arteriovenous fistulas are rare. Our case provides a nice example a combined endoscopic and endovascular approach aimed at achieving cure of the hydrocephalus and the Yasargil Type IV-C secondary VGM. We were able to avoid the placement of shunt hardware via ETV treatment of the patient's hydrocephalus. Furthermore, our case displays the impact of partial embolization on control and potential cure of these complex vascular malformations.

Background:Gamma Knife (GK) radiosurgery for pediatric arteriovenous malformations (AVM) of the brain presents a non-invasive treatment option. We report our institutional experience with GK for pediatric AVMs.Methods:We performed a retrospective review of all pediatric patients treated with GK for cerebral AVMs at our institution from November 2003 up to and including September 2014. Patient demographics, AVM characteristics, treatment parameters and AVM responses were recorded.Results:Nineteen patients were treated, with 4 lost to follow-up. The mean age was 14.2 years (range. 7-18 years), with 10 being males (52.6%). The mean AVM diameter and volume were 2.68 cm and 3.10 cm3respectively. The mean Spetzler-Martin (SM) and Pollock grades of the treated AVMs were 2.4 and 0.99 respectively. The mean follow-up was 62 months. All AVMs treated demonstrated a response on follow-up imaging. Nine of 15 (60.0%) patients displayed obliteration of their AVMs. Nine of 11 patients with a minimum of 3 years follow-up (81.8%) displayed obliteration, with SM and Pollock grades correlating to the chance of obliteration in this group. Two patients developed post-GK edema requiring short course dexamethasone therapy. No other major complications occurred. No permanent complications occurred.Conclusions:GK radiosurgery for pediatric AVMs offers a safe and effective treatment option, with low permanent complication rates during early follow-up.

This paper blends recent research on hierarchy and democratization to examine the theoretical and empirical costs of treating regime type exogenously in the literature most identified with studying its impact on international politics. It argues that the apparent peace among democratic states that emerges in the aftermath of World War I is not caused by domestic institutional attributes normally associated with democracy. Instead, this peace is an artifact of historically specific great power settlements. These settlements shape subsequent aggregate patterns of military conflict by altering the organizational configuration of the system in three critical ways—by creating new states, by altering hierarchical orders, and by influencing regime type in states. These claims are defended with a series of tests that show first how the statistical relationship between democracy and peace has exhibited substantial variation across great power orders; second, that this statistical relationship breaks down with theoretically motivated research design changes; and third, that great powers foster peace and similar regime types within their hierarchical orders. In short, the relationship between democracy and peace is spurious. The international political order is still built and managed by great powers.

We present a formal model of international bargaining between two states in which one government must negotiate with a domestic opposition faction to secure tax revenue for military spending. The model examines how robust the international order is to domestic political crises that activate a stark trade-off to a governing coalition. Namely, offering fiscal relief to stave off domestic revolution can simultaneously undermine the larger international political order by facilitating military spending that can, under some circumstances, result in sizable shifts in the relative distribution of military power between states. We find that two key domestic conditions influence the likelihood of preventive war: the distribution of income within the state's economy and the relative economic stake that opposition groups possess in international settlements.

Background: Despite the critical role played by neurosurgeons in performing radiosurgery, neurosurgery residents in Canada have limited exposure to radiosurgery during their training. A survey of neurosurgery residents and faculty along with radiation oncology faculty was conducted to analyze perspectives regarding incorporating formal radiosurgery training into the neurosurgery residency curriculum Methods: An online survey platform was employed. Descriptive statistics were used to summarize center and respondent characteristics. Categorical variables were compared using odds ratios and corresponding 95% confidence intervals. The chi-squared test was utilized to assess statistical significance. A value of pResults: The response rate was 31% (119/381); 87% (102/119) of respondents were from the neurosurgical specialty and 13% (17/119) from radiation oncology. Some 46% of residents (18/40) were “very uncomfortable” with radiosurgery techniques, and 57% of faculty (42/73) believed that dedicated radiosurgery training would be beneficial though impractical. No respondents felt that “no training” would be beneficial. A total of 46% of residents (19/41) felt that this training would be beneficial and that time should be taken away from other rotations, if needed, while 58% of faculty (42/73) and 75% (28/41) of residents believed that either 1 or 1-3 months of time dedicated to training in radiosurgery would suffice Conclusions: Canadian neurosurgeons are actively involved in radiosurgery. Despite residents anticipating a greater role for radiosurgery in their future, they are uncomfortable with the practice. With the indications for radiosurgery expanding, this training gap can have serious adverse consequences for patients. Considerations regarding the incorporation and optimal duration of dedicated radiosurgery training into the Canadian neurosurgery residency curriculum are necessary.

Background: The 2013 Physician Payments Sunshine Act mandates that all US drug and device manufacturers disclose payments to physicians annually in the Open Payments Database (OPD). We aimed to determine the prevalence, magnitude and nature of these payments to neurological surgery in 2015. Methods: Records of payments to physicians identified by the ‘neurological surgery’ taxonomy code in 2015 were accessed via the OPD. The data were analyzed in terms of the type and amounts of payments, companies making payments, and in comparison to previous studies. Results: In 2015, 330 companies made 83,690 payments ($99,048,607) to 7,613 physicians. The mean payment ($13,010) was substantially greater than the median ($114). Royalties and licensing accounted for the largest proportion of total payment value (74.2%), but only 1.7% of the total number. Food and beverage payments were the most commonly reported transaction (75%), but only 2.5% of the total value. Neurological surgery had the second highest average total payment per physician of any specialty. Conclusions: The overall value of payments to the neurological surgery specialty is driven by a small number of payments that may represent appropriate compensation for novel device development. The OPD provides an opportunity for increased transparency and for the interpretation of research in light of potential conflicts of interest.

Blastomyces dermatitidis is a dimorphic fungus which is potentially life-threatening if central nervous system (CNS) dissemination occurs. Sixteen patients with proven or probable CNS blastomycosis are presented. Median duration of symptoms was 90 days; headache and focal neurologic deficit were the most common presenting symptoms. Magnetic resonance imaging (MRI) consistently demonstrated an abnormality, compared to 58% of computed tomography scans. Tissue culture yielded the pathogen in 71% of histology-confirmed cases. All patients who completed treatment of an amphotericin B formulation and extended azole-based therapy did not relapse. Initial nonspecific symptoms lead to delayed diagnosis of CNS blastomycosis. A high index of suspicion is necessary if there is history of contact with an area where B. dermatitidis is endemic. Diagnostic tests should include MRI followed by biopsy for tissue culture and pathology. Optimal treatment utilizes a lipid-based amphotericin B preparation with an extended course of voriconazole.

Object:To review our institutional experience with Gamma Knife (GK) stereotactic radiosurgery in treating large vestibular schwannomas (VS) of 3 to 4 cm diameter.Methods:We conducted a retrospective cohort review of all patients treated with GK for VS at our institution between November 2003 and March 2012. Data on age, sex, VS volume, location and maximal diameter, House-Brackmann (HB) facial nerve scores pre and post-GK, Gardner-Robertson (GR) hearing score pre and post-GK, GK treatment parameters, VS response time, complications and clinical outcome was recorded.Results:A total of 28 patients during the defined time period were identified. Three patients were lost to follow-up. Mean follow-up was 34.5 months. Tumor control occurred in 92%, and was maintained in 85.7% at two years. Facial nerve or hearing preservation occurred in all treated compared to pre-GK status, as per HB and GR grading. Transient complications occurred in 80%. Temporary vestibular dysfunction occurred in seven patients (28%). One patient (4%) had the permanent complication of worsening pre-GK hemifacial spasm. Four patients (16%) developed hydrocephalus post-GK.Conclusion:GK stereotactic radiosurgery as a primary treatment modality for large VS can provide acceptable tumor control rates with good facial nerve and hearing preservation, and low complication rates.

Objectives: To summarize the clinical characteristics and outcomes of pediatric sports-related concussion (SRC) patients who were evaluated and managed at a multidisciplinary pediatric concussion program and examine the healthcare resources and personnel required to meet the needs of this patient population. Methods: We conducted a retrospective review of all pediatric SRC patients referred to the Pan Am Concussion Program from September 1st, 2013 to May 25th, 2015. Initial assessments and diagnoses were carried out by a single neurosurgeon. Return-to-Play decision-making was carried out by the multidisciplinary team. Results: 604 patients, including 423 pediatric SRC patients were evaluated at the Pan Am Concussion Program during the study period. The mean age of study patients was 14.30 years (SD: 2.32, range 7-19 years); 252 (59.57%) were males. Hockey (182; 43.03%) and soccer (60; 14.18%) were the most commonly played sports at the time of injury. Overall, 294 (69.50%) of SRC patients met the clinical criteria for concussion recovery, while 75 (17.73%) were lost to follow-up, and 53 (12.53%) remained in active treatment at the end of the study period. The median duration of symptoms among the 261 acute SRC patients with complete follow-up was 23 days (IQR: 15, 36). Overall, 25.30% of pediatric SRC patients underwent at least one diagnostic imaging test and 32.62% received referral to another member of our multidisciplinary clinical team. Conclusion: Comprehensive care of pediatric SRC patients requires access to appropriate diagnostic resources and the multidisciplinary collaboration of experts with national and provincially-recognized training in TBI.

Objectives Pre-trauma center care is a critical component in severe pediatric traumatic brain injury (TBI). For geographically large trauma catchment areas, optimizing increased intracranial pressure (ICP) management may potentially improve outcomes. This retrospective study examined ICP management in nontrauma centers and during interfacility transport to the trauma center. Methods Charts from a pediatric level I trauma center were reviewed for admissions between 2008 and 2013. Patients with a Glasgow Coma Scale score of 8 or less, head Abbreviated Injury Scale score of 3 or higher, and requiring intubation at a nontrauma center were included. Exclusion criteria included head injury secondary to drowning, stroke, obstetrical complications, asphyxia, and afflicted head trauma (younger than 5 years). Trauma center charts contained coalesced data from first responders, nontrauma centers, and transport. Results Twenty-five patients (74%) had increased ICP upon admission at trauma center, 48% experienced ICPs greater than 20 cm H2O within 12 hours of admission, 12% required an urgent craniotomy, and 16% had herniation syndromes on neuroimaging. Pre-trauma center ICP management included osmotherapy and head-of-bed elevation. Sixty-four percent of patients with increased ICP at trauma center admission received pre-trauma center ICP management. Conclusions Early increased ICP is a common presentation of severe pediatric TBI during pre-trauma center management. However, what constitutes optimal care remains unknown. Given the difficulties of diagnosing early increased ICP in this setting, prophylactic raising ICP-lowering strategies may be considered.

AT-22. ALISERTIB MONOTHERAPY IN THE TREATMENT OF RELAPSED ATYPICAL TERATOID RHABDOID TUMOR (ATRT) Magimairajan Issai Vanan1, Patrick McDonald2, Colin Kazina3, Junliang Liu1, Sherry Krawitz4, Martin Bunge5, Annie Ong1, and Brent Orr6; CancerCare Manitoba/Winnipeg Children’s Hospital, Winnipeg, MB, Canada; Pediatric Neuro-surgery/BC Children’s Hospital, Vancouver, BC, Canada; Pediatric Neuro-Surgery/University of Manitoba, Winnipeg, MB, Canada; Neuropathology/University of Manitoba, Winnipeg, MB, Canada; Radiology/University of Manitoba, Winnipeg, MB, Canada; Pathology/ St Jude Children’s Research Hospital, Memphis, TN, USA Atypical teratoid rhabdoid tumors (ATRTs) account for up to 20% of brain tumors in children less than 3yrs of age. The overall prognosis of ATRTs is extremely poor with median survival in the range of 10-18mths from the time of diagnosis. Aurora A Kinase (AURKA) encodes a protein that regulates the formationandstabilityof themitotic spindleand ishighlyactive inATRTthrough loss of the INI1 tumor suppressor gene. Alisertib (MLN8237) is a selective small molecule inhibitor of AURKA. We report a case of recurrent ATRT treated with alisertib monotherapy producing sustained and durable disease remission. Our patient underwent gross total resection (GTR) of the Posterior fossa tumor at diagnosis and was initially treated as per ACNS0333 protocol. She remained in remission for 15 months after completion of chemotherapy when she relapsed in the right frontal lobe. She underwent sub-total resection (STR) followed by focal IMRT (54Gy/30 fractions) followed by chemotherapy (DFCI-IRS-III, modified protocol) with Doxorubicin / Etoposide alternating with Actinomycin-D and triple intrathecal chemotherapy. After 7 months of treatment, she relapsed again in the right frontal region, presenting with focal seizures. She received 10 cycles of alisertib (60mg/m2 by mouth once daily for 7 days of a 21 day treatment cycle) monotherapyand is clinically stablewith her imaging showingsustained regression of disease. Somnolescence and neutropenia were the most common side effects seen in our patient. Neuro-Oncology 18:iii1–iii6, 2016. doi:10.1093/neuonc/now065.21 #The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Just when we thought we had seen it all, AJOB Neuroscience devotes pages to the head transplant. Ren and Canavero (2017) argue enthusiastically, but often incoherently for it; Wolpe (2017) argues r...

Background: Despite being mandatory for accreditation by the RCPSC and ACGME, little is known about how ethics education is undertaken during neurosurgery training. This study assessed the current state of ethics education in North American neurosurgery training programs. Methods: A web-based survey was developed based on ethics competencies outlined by the RCPSC and the ACGME and emailed to North American neurosurgery residency program directors(PD’s). Responses were analyzed using descriptive statistics. Results: 47/119 (40%) PD’s completed the survey. Most(74%) spent Conclusions: This study provides a snapshot of ethics education in neurosurgery training. Time constraints and a lack of expert faculty were seen as barriers to ethics education. Most program directors felt residents were well prepared to deal with ethical issues. Identified ethical topics of importance should be incorporated into training curricula.

This paper argues that the construction of sustainable peace settlements among great powers rests on a self-enforcing international bargain that impedes rapid shifts in the global distribution of military power and a series of stable fiscal bargains within great powers that both generate sufficient revenues to preserve a military deterrent and prevent programs of rapid armaments expansion. It examines how free resources— public property, natural resource wealth, international transfers, and sovereign lending—insulate governments from having to renegotiate the basic fiscal contract with society and can, as a consequence, create the domestic political capacity to sustain arms races and shift regional and global military balances to their advantage. These claims are examined by comparing the origins of World War I and the Cold War. The reexamination of World War I challenges the prevailing historical consensus by arguing that the primary cause of war lies within Russia rather than Germany. A discussion of early stages of the Cold War shows how the Truman and Eisenhower administrations both considered launching preventive war to solve the same fiscal dilemma faced by German leaders in July 1914.

Background: Industry funding of neurosurgery research is on the rise and this creates a conflict of interest (COI) with the potential to bias results. The reporting and handling of COI is impacted by the variation in policies and definitions between journals. In this study we sought to evaluate the prevalence and comprehensiveness of COI policies amongst leading neurosurgical journals. Methods: We conducted a cross-sectional study of publicly available online disclosure policies in the 20 highest-ranking neurosurgical journals, as determined by Google Scholar Metrics, in July of 2016. Results: Eighteen (89.5%) of the top neurosurgical journals included COI policy statements. Ten journals requested declaration of non-financial conflicts, while two journals defined a time period of interest for conflicts. Sixteen journals required declaration from the corresponding author, 13 from all authors, six from reviewers and five from editors. Five journals included COI declaration verification, management or enforcement. Journals with more comprehensive COI policies were significantly more likely to have higher h5-indices (p=0.003) and higher impact factors (p=0.01). Conclusions: In 2016, the majority of high-impact neurosurgical journals had publicly available COI disclosure policies. Policies varied substantially across neurosurgical journals; but COI comprehensiveness was associated with impact factor and h5-index. More comprehensive and consistent COI policies will facilitate increased transparency in neurosurgery research.

This paper builds on the growing capitalist peace research program by examining how large quantities of public property influence the likelihood of conflict between states. Drawing on the logic of the commitment problem, it develops two explanations linking the predominance of public property in an economy to the likelihood of being the target of military conflict, defined to include both militarized disputes and war. Empirical support for this hypothesis is generated with a brief illustrative case and a series of statistical tests with monadic and directed dyadic research designs. A final section discusses how these findings suggest that capitalism plays a larger role than democracy in limiting military conflict between states.

The inhomogeneous cosmological reionization process leaves tangible imprints in the intergalactic medium (IGM) down to z approx 4-5. The Lyalpha forest flux power spectrum provides a potentially powerful probe of the epoch of reionization. With the existing Sloan Digital Sky Survey I/II quasar sample, we show that two cosmological reionization scenarios, one completing reionization at z = 6 and the other at z = 9, can be distinguished at approx7sigma level by utilizing Lyalpha forest absorption spectra at z = 3.9-4.1 in the absence of other physical processes that may also affect the Lyalpha flux power spectrum. The difference may not be distinguishable at such high significance after marginalization over other effects, but, in any case, one will need to consider this effect in order to correctly interpret the power spectrum in this redshift range. The redshift range z = 4-5 may provide the best window because there are still enough transmitted flux and quasars to measure precise statistics of the flux fluctuations, and the IGM still retains a significant amount of memory of reionization.

Winter sports are often associated with high speed, which carries with it the potential for collision. As such, head injuries are among the more commonly encountered injuries in winter-related sporting activities. This article focuses on popular winter sports such as downhill skiing and snowboarding, sledding, snowmobiling, ice skating, and hockey. In virtually all of these activities, the incidence and severity of head injuries can be reduced by the use of appropriate protective headgear.

This article examines how commerce promotes peace between states. It diverges from the commercial peace literature and its predominant focus on international trade by looking inside the domestic economy to see how its structure influences conflict. Drawing on selectorate theory, I argue that substantial quantities of public property generate fiscal autonomy for governments, strengthen their hold on the domestic reigns of power, and create opportunities to pursue more aggressive foreign policies. A series of statistical tests shows that greater quantities of publicly held assets increase the likelihood that a state will participate in military conflict. Given that the predominance of privately held property is one of the defining institutions of capitalism, these results support the claim that capitalism promotes peace.

The costs and unmet expectations of the democracy promotion project in Iraq and the wider Middle East have sparked a broad debate about the future of U.S. grand strategy. In the chorus for change, some suggest that the United States should return to such principles of liberal internationalism as multilateralism and financial beneficence, which marked the golden era of U.S. diplomacy in the years immediately following the end of World War II. Others insist that U.S. foreign policy needs to be reestablished in a more pragmatic realism that responds to the global balance of power and resists the overuse of military muscle to promote democracy around the world. Greater reliance on U.S. economic power can inject more prudence into foreign policy without abandoning the historical U.S. goal of promoting free- dom and political reform around the world. The United States possesses the largest and most vibrant market in the global economy and can integrate this unique political asset more effectively in the larger global struggle against ter- rorism and radical Islam. Unilaterally eliminating trade barriers on imported goods from moderate Islamic states critical to combating terrorism, such as Bangladesh, Ethiopia, Indonesia, Kenya, Malaysia, Mali, Mauritania, Nigeria, Pakistan, the Philippines, Tanzania, and Turkey, could strengthen Washing- ton's capacity to promote political moderation and cultivate local influence within these countries. As foreign businesses and workers come to depend on U.S. consumers for profits and jobs, they become important allies in internal struggles taking place around the world between the forces of modernization, globalization, and tol

Despite substantial evidence that international trade has promoted peace in the post—World War II era, the commercial peace research program still faces an important historical challenge. Dramatic economic integration in the nineteenth century failed to prevent the increasing interstate hostilities that culminated in the outbreak of war in 1914. This article uses a theoretical revision grounded in standard trade theory to reexamine the relationship between commerce and peace in the fifty years before World War I, a period often referred to as the first era of globalization. The article focuses on domestic conflict over commercial policy rather than on interdependence to understand the conditions under which globalization promotes peace. In a sample dating from 1865 to 1914, the authors find that lower regulatory barriers to commerce reduce participation in militarized interstate disputes. Contradicting conventional wisdom, this evidence affirms a basic premise of commercial liberalism during the first era of globalization—free trade promotes peace.

We combine the high resolution spectra with cosmic microwave background (CMB) including 3-year WMAP, and supernovae (SN) and galaxy clustering constraints with the Ly-α forest power spectrum from the Sloan Digital Sky Survey (SDSS) to derive new constraints on cosmological parameters. The existing Ly-α power spectrum analysis is supplemented by constraints on the mean flux decrement which were derived by a principle component analysis of quasar continua. This improves the Ly-α constraints on the linear power. We find a mild conflict between the WMAP3 and Ly-α power spectrum amplitudes at the ∼2 σ level, which is partially alleviated by the inclusion of other observations: we find σ 8 = 0.85 ± 0.02 compared to σ 8 = 0.80 ± 0.03 without Ly-α. For the slope we find n s = 0.965 ± 0.012. No evidence for the running of the spectral index is found in the combined analysis, d n /d ln k = −(1.5 ± 1.2) × 10 −2 , which is in agreement with inflation.

Background: Transitioning from medical school to residency is difficult and stressful, necessitating innovation in easing this transition. In response, a Canadian neurosurgical Rookie Camp was designed and implemented to foster acquisition of technical, cognitive and behavioral skills among incoming Canadian post graduate year one (PGY-1) neurosurgery residents. Methods: The inaugural Rookie Camp was held in July 2012 in Halifax. The curriculum was developed based on a national needs-assessment and consisted of a pre-course manual, 7 case-based stations, 4 procedural skills stations and 2 group discussions. The content was clinically focused, used a variety of teaching methods, and addressed multiple CanMEDS competencies. Evaluation included participant and faculty surveys and a pre-course, post-course, and 3-month retention knowledge test. Results: 17 of 23 PGY-1 Canadian neurosurgical residents participated in the Camp. All agreed the course content was relevant for PGY-1 training and the experience prepared them for residency. All participants would recommend the course to future neurosurgical residents. A statistically significant improvement was observed in knowledge related to course content (F(2,32) = 7.572, pConclusion: The inaugural Canadian Neurosurgery Rookie Camp for PGY-1 residents was successfully delivered, with engagement from participants, training programs, the Canadian Neurosurgical Society, and the Royal College. In addition to providing fundamental knowledge, which was shown to be retained, the course eased junior residents’ transition to residency by fostering camaraderie and socialization within the specialty.

We present N-body simulation calculations of the dependence of the power spectrum of non-linear cosmological mass density fluctuations on the equation of state of the dark energy, w=p/rho. At fixed linear theory power, increasing w leads to an increase in non-linear power, with the effect increasing with k. By k=10 h/Mpc, a model with w=-0.75 has ~12% more power than a standard cosmological constant model (w=-1), while a model with w=-0.5 has ~33% extra power (at z=0). The size of the effect increases with increasing dark energy fraction, and to a lesser extent increasing power spectrum normalization, but is insensitive to the power spectrum shape (the numbers above are for Omega_m=0.281 and sigma_8=0.897). A code quantifying the non-linear effect of varying w, as a function of k, z, and other cosmological parameters, which should be accurate to a few percent for k, accepted by MNRAS, code at http://www.cita.utoronto.ca/~pmcdonal/code.html, corrected error in plotting Smith et al. prediction - now agree perfectly when w=-1

Impaired regulation of intracellular calcium is thought to adversely affect synaptic plasticity and cognition in the aged brain. Comparing young (2–3 months) and aged (23–26 months) Fisher 344 rats, stratum radiatum-evoked CA1 field EPSPs were smaller and long-term potentiation (LTP) was diminished in aged hippocampal slices. Resting calcium, in presynaptic axonal terminals in the CA1 stratum radiatum area, was elevated in aged slices. Loading the slice with the calcium chelator, BAPTA-AM, depressed LTP in young slices, but enhanced this plasticity in old slices. Forty-five minutes following LTP-inducing high frequency stimulation, resting calcium levels were significantly increased in both young and old presynaptic terminals, and significantly reduced by pretreatment with BAPTA-AM. In vivo, intraperitoneal administration of BAPTA-AM prior to training in the reference memory version of the Morris water maze test, significantly improved the acquisition of spatial learning in aged animals, without a significant effect in young rats. These results support the hypothesis that increasing intracellular neuronal buffering power for calcium in aged rats ameliorates age-related impaired synaptic plasticity and learning.

Hypothalamic hamartomas (HH) are rare lesions of ectopic neural tissue arising from the wall of the hypothalamus. Patients with HH can present with gelastic seizures, precocious puberty or both 1 . Seizures are usually progressive and accompanied by worsening behavioral problems and developmental delay 1 . Stereotactic radiosurgery (SRS) has been shown to be safe and effective, resulting in improvement in s eizures and halting tumor progression. Gamma Knife (GK) radiosurgery in the treatment of hypothalamic hamartoma has reported Engel Class 1 seizure status of up to 60%, with improvement in behavioral status in some cases 2 . Post-treatment magnetic resonance (MR) imaging as reported in the literature has not demonstrated significant changes within the treated areas of a HH. The authors report the case of a four year-old boy with a symptomatic hypothalamic hamartoma treated with GK radiosurgery. Serial MR imaging after treatment revealed significant and progressive edema and swelling at the treatment site, with increased T2 signal change and gadolinium uptake lasting one year after treatment and eventually resolving spontaneously. Although not accompanied by clinical worsening, these changes have not been p reviously reported in SRS for HH.

This article explores how the dramatic expansion of British trade in the decades prior to World War I affected Britain's ability to raise an army. We first develop a simple institutionally based model of British army recruiting which we then perturb by expanding trade while holding all other variables constant. Our theoretical analysis suggests that the expansion of trade would impede Britain's ability to raise an army, a prediction that finds substantial support in the historical record using both quantitative and qualitative analysis. Contrary to the conventional wisdom that trade enhances a state's military power, we find that the expansion of trade did not ease Britain's resource constraints by making labor more freely available for military purposes. Rather, by raising the civilian demand for labor, the expansion of trade made labor more expensive and difficult to mobilize, even as a more effective army became more important to British strategy.

Aim: To examine the online personnel and practice profiles of concussion healthcare providers in the USA. Methods: We conducted independent, blinded, Google Internet searches for concussion healthcare providers using the terms ‘concussion clinic’ and ‘concussion program’ and each American state and completed a critical appraisal of healthcare personnel and services at these websites. Results: A total of 184 concussion healthcare providers were identified. Despite offering care to traumatic brain injury (TBI) patients, access to professionals with expertise in TBI including neuropsychologists (40.8%), neurologists (33.7%) and neurosurgeons (21.7%) was variable across sites. Conclusion: Concussion healthcare in the USA is presently delivered by a range of healthcare professionals with varying levels of training in TBI offering a variety of services.

Objective Summarise clinical characteristics, outcomes, and healthcare resources and personnel needs of paediatric sports-related concussion (SRC) patients who were evaluated and managed at a multi-disciplinary paediatric concussion program. Design Retrospective cohort study Setting Paediatric, multi-disciplinary concussion clinic Participants 423 paediatric SRC patients: 14.3 years (SD: 2.3), 59.6% males, 43.0% hockey-related, and 75.8% acute SRC Interventions (or assessment of risk factors) Initial assessment and diagnosis by a neurosurgeon with the multi-disciplinary team completing Return-to-Play decision-making. On-site neurosurgeon, neuropsychologist, vestibulo-ocular therapist, and exercise physiologist and referrals to neurology and psychiatry Outcome measures SRC diagnosis and recovery were defined by the 2013 Zurich Consensus Guidelines. Post-Concussion Syndrome was diagnosed using ICD-10 criteria of at least 3 symptoms at 30 days or more. Outcomes included demographic and injury data, healthcare resources and personnel utilised, and recovery Main results Overall, 294 (69.5%) of SRC patients met the clinical criteria for recovery, 75 (17.7%) were lost to follow-up, 53 (12.5%) remained in treatment, and 1 died (0.2%). In acute patients, median time to initial consultation was 7 days (IQR: 5, 12). Median days to recovery among acute SRC patients with complete follow-up was 23 days (IQR: 15, 36) and 44.1% of acute SRC patients were diagnosed with PCS. 25.3% of SRC patients underwent at least one diagnostic imaging test and 32.6% received referral to another member of our multi-disciplinary clinical team. Conclusions Youth received comprehensive care with access to appropriate diagnostic resources and multi-disciplinary collaboration of experts with national and provincially-recognised training in TBI Competing interests None.

A 28-month female with a clinical diagnosis of neurocutaneous melanosis and numerous intracranial abnormalities (including a right choroid plexus tumor and left hemimegalencephaly) presented with a rapidly expanding tumor in the left occipital cerebrum. Microscopic examination of the resected specimen revealed a myxoid mesenchymal neoplasm consisting of fusiform cells that were immunoreactive for vimentin, CD34, and P53 but no melanocyte markers. Focused amplicon deep sequencing on DNA extracted from the brain tumor and a cutaneous nevus revealed a heterozygous (c.37G > C; p.G13R) substitution in the NRAS gene. DNA sequencing of “normal” skin and buccal swab showed the identical NRAS change albeit at lower allelic frequency. Her parents did not harbor the NRAS mutation. The skin lesion, but not the brain tumor, had a BRAF mutation (c.1397G > T; p.G466V). A germline single nucleotide polymorphism in MET was found in the child and her father (c.3209C > T; p.T1010I). The findings suggest NRAS mosaicism that occurred sometime after conception and imply an oncogenic role of the activating NRAS mutation in both the brain and skin lesions in this child.

✓Shunt failure is commonly associated with infection or mechanical obstruction of the shunt system. The presence of eosinophilia in the cerebrospinal fluid (CSF) has been associated with CSF shunt failure and may be related to both latex and shunt allergies. The authors describe the case of a child with a latex allergy who presented with 10 episodes of shunt failure over a period of 93 months. Cerebrospinal fluid sampling demonstrated persistent eosinophilia (3–36%) and negative cultures. Pathological examination of the ventricular catheter on 3 occasions demonstrated mechanical obstruction by inflammatory debris consisting largely of eosinophils and multinucleated giant cells. On the suspicion that the child might have some uncharacterized allergy to the shunt hardware, shunt replacement was performed using an “extracted” shunt system. The child has remained free of shunt malfunction for > 2 years since the last surgery. Immune responses to unpolymerized silicone are discussed.

The skull may be a site of metastasis in malignancies such as carcinoma of the breast, prostate, lung, and multiple myeloma. The majority of patients with skull metastases are asymptomatic or present with localized swelling which is often painless. While subdural hematoma has been commonly associated with metastatic disease involving the dura, hemorrhage from a skull metastasis remains a rare occurrence. We present the case of acute epidural hematoma resulting from metastatic esophageal carcinoma to the skull.

Arachnoid cysts are relatively common lesions encountered in neurosurgical practice. While arachnoid cysts are most commonly observed to remain of fixed volume over time, little is actually known about their natural history and optimal method of treatment. We present 2 young children with middle fossa arachnoid cysts. In 1 child, the cyst enlarged over time, prompting neurosurgical intervention. However, in the other child, the cyst resolved spontaneously without intervention. The child whose cyst enlarged underwent cyst wall fenestration and cyst-peritoneal shunting. For the child whose arachnoid cyst disappeared without treatment, there was no history of trauma or antecedent headache. These 2 cases serve to illustrate in a single report that middle fossa arachnoid cysts can be dynamic in nature, with some growing in size while others spontaneously resolving. In both cases presented, the temporal lobe on the affected side was compressed by the large cyst. Following treatment or spontaneous resolution of the cyst, the temporal lobe reexpanded, suggesting a normal volume of temporal lobe, and not temporal lobe agenesis. In asymptomatic patients with moderate-sized arachnoid cysts such as the ones demonstrated in these case reports, we suggest close follow-up with serial imaging before deciding on a final treatment plan.

Primary intracranial sarcomas are rare tumors of mesenchymalorigin in the central nervous system (CNS). Spontaneoushemorrhage, while not an uncommon presentation of braintumors, has not been described in primary cerebral sarcoma.We report the case of a 43 yearold woman presenting with spontaneous hemorrhage into aprimary cerebral fibrosarcoma, and discuss this case inthe context of the diagnostic criterions of theserare tumors, previous reports of intracranial sarcomas andmechanisms of intratumoral hemorrhage.

Introduction:Stereotactic radiosurgery offers a unique and effective means of controlling cavernous sinus meningiomas with a low rate of complications.Methods:We retrospectively reviewed all cavernous sinus meningiomas treated with Gamma Knife (GK) radiosurgery between November 2003 and April 2011 at our institution.Results:Thirty patients were treated, four were lost to follow- up. Presenting symptoms included: headache (9), trigeminal nerve dysesthesias/paresthesias (13), abducens nerve palsy (11), oculomotor nerve palsy (8), Horner's syndrome (2), blurred vision (9), and relative afferent pupillary defect (1). One patient was asymptomatic with documented tumor growth. Treatment planning consisted of MRI and CT in 17 of 30 patients (56.7%), the remainder were planned with MRI alone (44.3%). There were 8 males (26.7%) and 22 females (73.3%). Twelve patients had previous surgical debulking prior to radiosurgery. Average diameter and volume at time of radiosurgery was 3.4 cm and 7.9 cm3 respectively. Average dose at the 50% isodose line was 13.5 Gy. Follow-up was available in 26 patients. Average follow-up was 36.1 months. Mean age 55.1 years. Tumor size post GK decreased in 9 patients (34.6%), remained stable in 15 patients (57.7%), and continued to grow in 2 (7.7%). Minor transient complications occurred in 12 patients, all resolving. Serious permanent complications occurred in 5 patients: new onset trigeminal neuropathic pain (2), frame related occipital neuralgia (1), worsening of pre-GK seizures (1), and panhypopituitarism (1).Conclusion:GK offers an effective treatment method for halting meningioma progression in the cavernous sinus, with an acceptable permanent complication rate.

A 15-month-old girl with hydrocephalus from an intraventricular hemorrhage presented to the emergency department with irritability, lethargy and vomiting. Our neurosurgery team had inserted a ventriculoperitoneal shunt 10 months earlier. Computed tomography of the patient’s brain showed enlarged

Sleep apnea is a rare but well-known clinical feature of disorders of the craniocervical junction. It may be obstructive or central in nature, and rarely presents without other neurological symptoms. We report the cases of two children, presenting with isolated central sleep apnea leading to a diagnosis of type I Chiari malformation. Surgical treatment resulted in a dramatic improvement in respiratory parameters during sleep, both clinically and on polysomnography. We discuss this uncommon presentation of type I Chiari malformation and suggest that it be considered in the differential diagnosis of central sleep apnea in children, as posterior fossa decompression may lead to significant clinical improvement.

It is shown that 21 cm intensity mapping could be used in the near term to make cosmologically useful measurements. Large scale structure could be detected using existing radio telescopes, or using prototypes for dedicated redshift survey telescopes. This would provide a measure of the mean neutral hydrogen density, using redshift space distortions to break the degeneracy with the linear bias. We find that with only 200 hours of observing time on the Green Bank Telescope, the neutral hydrogen density could be measured to 25% precision at redshift 0.54, Comment: 6 pages, 5 figures. Submitted to Phys. Rev. D. Addressed reviewer comments. Changed figure format, added more detailed technical discussion, and added forecasts for aperture arrays. Added references.