bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship of Transportation Access and Connectivity to Local Economic Outcomes
Authors: Alstadt Brian , Weisbrod Glen , Cutler Derek
Published: February 2013

Past research has shown that transportation system improvements can affect economic growth and productivity by changing access to markets and connectivity to intermodal terminals. However, most past research has adopted singular measures of market access and business productivity. This study demonstrates how various transportation projects can have larger or smaller impacts on business concentration and productivity by affecting different aspects of market access in areas with different business mixes. The study demonstrates these relationships through a two-step process. First, it defines seven types of access and connectivity measures, including access to labor markets, truck delivery markets, and intermodal terminals. The process then develops econometric models of the relationship between access and connectivity characteristics of local areas and relative levels of business productivity, job concentration, and export base. These relationships are estimated with simultaneous, nonlinear equations that allow access threshold effects to be recognized and for different relationships to apply for 54 industry sectors. The results confirm that different types of access are relevant to different industry sectors. As a consequence, the productivity and agglomeration of a given industry in a given area can be related to more than one dimension of accessibility. These results can have important implications for estimating the wider economic benefits of transportation investment and suggest the need to consider both industry detail and forms of accessibility in order to calculate accurately the relative impact of specific project proposals.
Investigating the Influence of Environmentalism and Variety Seeking on Mode Choice
Authors: Rieser-Schüssler Nadine , Axhausen Kay W.
Published: February 2013

In the transport modeling community, there is a growing consensus that socioeconomic attributes alone will not suffice to characterize travelers and make forecasts about their travel behavior. Therefore, an increasing number of recent studies have integrated latent variables representing attitudes, perceptions, and preferences into choice models. Because it is impossible to measure latent variables directly, psychometric scales are used as indicators. For the study presented in this paper, psychometric scales for environmentalism and variety seeking were developed and tested in a mail-back survey that included a 1-day travel diary and a questionnaire about socioeconomic characteristics. A factor analysis was carried out to establish predominant attitudinal factors, which were then used as latent variables in a mode choice model. The results of the estimated choice models show that the three latent variables investigated—awareness of environmental problems, denial of environmental issues, and desire for variety in one's daily routine—influenced the mode choices of the study participants in different ways that may be attributable to other socioeconomic characteristics of the participants. This finding indicates that the scales developed for this study are suitable for capturing attitudes that are relevant to transport behavior research.
Value of Life Cycle in Explaining Trip-Making Behavior and Improving Temporal Stability of Trip Generation Models
Authors: Huntsinger Leta F. , Rouphail Nagui M.
Published: February 2013

Travel demand models are valuable tools in the transportation planning process; based on sound theory, these models bring a quantitative element to what is predominantly a political process. The forecasts output from these models guide decision makers in evaluating and selecting transportation programs and projects. Developing a better understanding of the factors that influence travel behavior, the changes in travel behavior over time, and the variables that best capture these changes may lead to the development of models that are more stable over time, increase the analyst's confidence in model results and lead to more cost-effective investment decisions. This paper investigates the life cycle as one such class of variables. In this context, “life cycle” is defined as the stage a family is in at a given time as related to factors such as the number and age of adults in the household; the presence, number, and age of children; and worker status. Using various statistical tests to evaluate the usefulness of the life cycle, the paper presents evidence to indicate that the life cycle has a strong influence on trip-making behavior while also improving stability in trip rates over time. These findings suggest that advanced trip generation models that accommodate more independent variables may lead to improved models, are more temporally stable, and better capture the dynamics that influence trip making.
Network Route-Choice Evolution in a Real-World Experiment
Authors: Tawfik Aly M. , Rakha Hesham A.
Published: February 2013

Route choice models are a cornerstone in many transportation engineering applications. Two main types of route choice models can be found in the literature: first, mathematical network-oriented models such as stochastic user equilibrium and, second, behavioral driver-oriented models such as random utility models. Although the former models are much more widely used in the transportation engineering realm, evidence of their inadequacy is growing continuously. The degree of their inadequacy, however, remains debatable. Two major criticisms of the theory are the unrealistic assumptions of human perceptions and the inability to incorporate driver heterogeneity. However, attempts to incorporate driver heterogeneity into the behavioral driver-oriented route choice models, too, are still inadequate. Another major limitation in the literature is that because of cost and past technological limitations, only a few studies are based on real-world experiments. Most studies are based on either stated preference surveys or travel simulators. This work analyzes results of a real-world route choice experiment with a sample of 20 drivers who made more than 2,000 real-world choices. Network and driver learning evolutions were recorded and analyzed. Findings of the experiment include the following: (a) with learning and network experience, real-world route choice percentages seem to be converging to specific values; however, these values are mostly different from those derived by using stochastic user equilibrium expectations; (b) four types of heterogeneous driver learning and choice evolution patterns are identified; and (c) the identified learning patterns are modeled and found predictable on the basis of driver and choice situation variables.
Conceptual Model to Explain Turning Points in Travel Behavior
Authors: Chatterjee Kiron , Sherwin Henrietta , Jain Juliet , Christensen Jo , Marsh Steven
Published: February 2013

Existing knowledge on cycling behavior, as with travel behavior in general, is based mainly on cross-sectional studies. It is questionable how much can be learned about the reasons for behavioral change from such studies. A major investment program to promote cycling in 12 English cities and towns between 2008 and 2011 provided the opportunity to study the bicycle use of residents and how that use was affected by the investment. Face-to-face interviews collected biographical information on travel behavior and life-change events during the investment period for 144 research participants and probed the reasons for changes in bicycle use. Theory (from the life course perspective) and preliminary analysis of the interview data were used to develop a conceptual model that hypothesized that turning points in travel behavior were triggered by contextual change (a life-change event or change in the external environment) and mediated by intrinsic motivations, facilitating conditions, and personal history. The model provided an effective means of explaining turning points in bicycle use. The analysis of the interview data showed how the nature of behavioral influences (in particular, life-change events and intrinsic motivations) varied over the life course. The research highlights the advantages of viewing travel behavior change in the context of people's evolving lives and how that approach can help in developing transport policies and practices.
Link-Based Route Choice considering Risk Aversion, Disappointment, and Regret
Authors: Fonzone Achille , Schmöcker Jan-Dirk , Ma Jiangshan , Fukuda Daisuke
Published: February 2013

In networks with uncertain link travel times, route guidance information should consider traveler preferences. Risk-averse travelers prefer safer options but might feel unsatisfied if it is found that their decisions have been based on the wrong expectations. This paper therefore proposes a new approach to take regret, disappointment, and risk aversion into consideration in route navigation. Limited information is assumed: The router knows minimum and maximum travel times of links but not the probability distribution of link travel times. Routes using only potentially optimal links are chosen by weighting the travel times scenarios expected on a given path and taking into account the cost of alternative options. Two approaches are explored, referred to as global and local search. The local search can be implemented as a fast method avoiding path search by guiding travelers link by link. As a drawback local search potentially can lead to cyclic paths. Possibilities to overcome the cyclic path issue and boundary properties of both approaches are discussed. Monte Carlo simulation on a U.S. network suggests that the two approaches can provide good solutions to the problem of route choice under severe lack of information. The local search seems to be particularly promising.
Twelve-month results of a clinical pilot study utilizing pedicle-lengthening osteotomy for the treatment of lumbar spinal stenosis
Authors: Mlyavykh Sergey , Ludwig Steven C. , Mobasser Jean-Pierre , Kepler Christopher K. , Anderson D. Greg
Published: February 2013

Object

Lumbar spinal stenosis (LSS) is a common condition that leads to significant disability, particularly in the elderly. Current therapeutic modalities for LSS have certain drawbacks when applied to this patient population. The object of this study was to define the 12-month postoperative outcomes and complications of pedicle-lengthening osteotomies for symptomatic LSS.

Methods

A prospective, single-treatment clinical pilot study was conducted. A cohort of 19 patients (mean age 60.9 years) with symptomatic LSS was treated by pedicle-lengthening osteotomy procedures at 1 or 2 levels. All patients had symptoms of neurogenic claudication or radiculopathy secondary to LSS and had not improved after a minimum 6-month course of nonoperative treatment. Eleven patients had a Meyerding Grade I degenerative spondylolisthesis in addition to LSS. Clinical outcomes were measured using the Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ), 12-Item Short-Form Health Survey (SF-12), and a visual analog scale (VAS). Procedural variables, neurological outcomes, adverse events, and radiological imaging (plain radiographs and CT scans) were collected at the 1.5-, 3-, 6-, 9-, and 12-month time points.

Results

The pedicle-lengthening osteotomies were performed through percutaneous approaches with minimal blood loss in all cases. There were no operative complications. Four adverse events occurred during the follow-up period. Clinically, significant improvement was observed in the mean values of each of the outcome scales (comparing preoperative and 12-month values): ODI scores improved from 52.3 to 28.1 (p < 0.0001); the ZCQ physical function domain improved from 2.7 to 1.8 (p = 0.0021); the SF-12 physical component scale improved from 27.0 to 37.9 (p = 0.0024); and the VAS score for leg pain while standing improved from 7.2 to 2.7 (p < 0.0001). Imaging studies, reviewed by an independent radiologist, showed no evidence of device subsidence, migration, breakage, or heterotopic ossification. Thin-slice CT documented healing of the osteotomy site in all patients at the 6-month time point and an increase in the mean cross-sectional area of the spinal canal of 115%.

Conclusions

Treatment of patients with symptomatic LSS with a pedicle-lengthening osteotomy procedure provided substantial enlargement of the area of the spinal canal and favorable clinical results for both disease-specific and non–disease-specific outcome measures at the 12-month time point. Future studies are needed to compare this technique to alternative therapies for lumbar stenosis.
Strategies to maximize resection of complex, or high surgical risk, low-grade gliomas
Authors: Wilden Jessica A. , Voorhies Jason , Mosier Kristine M. , O'Neill Darren P. , Cohen-Gadol Aaron A.
Published: February 2013

Object

Early and aggressive resection of low-grade gliomas (LGGs) leads to increased overall patient survival, decreased malignant progression, and better seizure control. This case series describes the authors' approach to achieving optimal neurological and surgical outcomes in patients referred by outside neurosurgeons for stereotactic biopsy of tumors believed to be complex or a high surgical risk, due to their diffuse nature on neuroimaging and their obvious infiltration of functional cortex.

Methods

Seven patients underwent individualized neuroimaging evaluation preoperatively, which included routine brain MRI with and without contrast administration for intraoperative neuronavigation, functional MRI with speech and motor mapping, diffusion tensor imaging to delineate white matter tracts, and MR perfusion to identify potential foci of higher grade malignancy within the tumor. Awake craniotomy with intraoperative motor and speech mapping was performed in all patients. Tumor removal was initiated through a transsylvian approach for insular lesions, and through multiple corticotomies in stimulation-confirmed noneloquent areas for all other lesions. Resection was continued until neuronavigation indicated normal brain, cortical or subcortical stimulation revealed functional cortex, or the patient began to experience a minor neurological deficit on intraoperative testing.

Results

Gross-total resection was achieved in 1 patient and subtotal resection (> 80%) in 6 patients, as assessed by postoperative MRI. Over the average follow-up duration of 31 months, no patient experienced a progression or recurrence. Long-term seizure control was excellent in 6 patients who achieved Engel Class I outcomes. Neurologically, all 7 patients experienced mild temporary deficits or seizures that completely resolved, and 1 patient continues to have mild expressive aphasia.

Conclusions

Significant resection of diffuse, infiltrating LGGs is possible, even in presumed eloquent cortex. Aggressive resection maximizes seizure control and does not necessarily cause permanent neurological deficits. Individualized preoperative neuroimaging evaluation, including tractography and awake craniotomy with intraoperative speech and motor mapping, is an essential tool in achieving these outcomes.
Technical nuances for surgery of insular gliomas: lessons learned
Authors: Rey-Dios Roberto , Cohen-Gadol Aaron A.
Published: February 2013

Insular gliomas were traditionally considered a nonsurgical entity due to the high morbidity associated with resection. For the past 20 years, advances in microsurgical and brain mapping techniques have allowed neurosurgeons to resect insular gliomas with acceptable morbidity rates. Maximizing the extent of resection is nowadays the goal of surgery since this has proven to be an independent factor contributing to longer survival. Despite much progress, insular tumors remain a challenge for the neurosurgeon due to the complex anatomy of the region and technical expertise required to minimize morbidity during surgery. Herein, the authors describe the current surgical nuances, based on their experience and a literature review, that will allow the surgeon to achieve a thorough resection while ensuring patient safety. The key factors for successful surgery in the insular region include detailed knowledge of the surgical anatomy, mastery of the nuances of cortical and subcortical mapping methods, and meticulous microsurgical technique.
Molecular genetics of low-grade gliomas: genomic alterations guiding diagnosis and therapeutic intervention. 11th Annual Frye-Halloran Brain Tumor Symposium
Authors: Jones Pamela S. , Dunn Gavin P. , Barker Fred G. , Curry William T. , Hochberg Fred H. , Cahill Daniel P.
Published: February 2013

Object

The authors' goal was to review the current understanding of the underlying molecular and genetic mechanisms involved in low-grade glioma development and how these mechanisms can be targets for detection and treatment of the disease and its recurrence.

Methods

On October 4, 2012, the authors convened a meeting of researchers and clinicians across a variety of pertinent medical specialties to review the state of current knowledge on molecular genetic mechanisms of low-grade gliomas and to identify areas for further research and drug development.

Results

The meeting consisted of 3 scientific sessions ranging from neuropathology of IDH1 mutations; CIC, ATRX, and FUBP1 mutations in oligodendrogliomas and astrocytomas; and IDH1 mutations as therapeutic targets. Sessions consisted of a total of 10 talks by international leaders in low-grade glioma research, mutant IDH1 biology and its application in glioma research, and treatment.

Conclusions

The recent discovery of recurrent gene mutations in low-grade glioma has increased the understanding of the molecular mechanisms involved in a host of biological activities related to low-grade gliomas. Understanding the role these genetic alterations play in brain cancer initiation and progression will help lead to the development of novel treatment modalities than can be personalized to each patient, thereby helping transform this now often-fatal malignancy into a chronic or even curable disease.
Intraoperative cortical mapping of visuospatial functions in parietal low-grade tumors: changing perspectives of neurophysiological mapping
Authors: Talacchi Andrea , Squintani Giovanna Maddalena , Emanuele Barbara , Tramontano Vincenzo , Santini Barbara , Savazzi Silvia
Published: February 2013

Object

The aim of this study was to explore the feasibility of intraoperative visuospatial mapping with the same criteria currently used to define essential language areas.

Methods

The authors compared surgical procedures in 2 patients with similar tumors (Grade II oligodendroglioma in the right parietal lobe) undergoing awake, image-assisted surgery for lesion removal with intraoperative neurophysiological monitoring. The line bisection task was used in both patients but with different criteria.

Results

In the first case, the authors respected any area, even within the tumor, where significant interference was found (a stimulation-induced error in 2 of 3 applications defined an essential area). In the second case, they removed 1 essential area located in the tumor and recorded an uneventful clinical response soon thereafter. They continued to monitor the patient without stimulation and stopped the resection when the patient was close to the criteria valid for defining spatial neglect. The signs of spatial neglect were present for 3 days postoperatively and then cleared spontaneously. Subtotal tumor removal was achieved in both cases.

Conclusions

Evidence in the present study reveals that areas for visuospatial functions cannot be assessed with the same criteria used for language functions, since essential areas located in the tumor can be safely removed.
Long-term ongoing cortical remodeling after contralateral C-7 nerve transfer
Authors: Hua Xu-Yun , Liu Bin , Qiu Yan-Qun , Tang Wei-Jun , Xu Wen-Dong , Liu Han-Qiu , Xu Jian-Guang , Gu Yu-Dong
Published: February 2013

Object

Contralateral C-7 nerve transfer was developed for the treatment of patients with brachial plexus avulsion injury (BPAI). In the surgical procedure the affected recipient nerve is connected to the ipsilateral motor cortex, and the dramatic peripheral alteration may trigger extensive cortical reorganization. However, little is known about the long-term results after such specific nerve transfers. The purpose of this study was to investigate the long-term cortical adaptive plasticity after BPAI and contralateral C-7 nerve transfer.

Methods

In this study, 9 healthy male volunteers and 5 male patients who suffered from right-sided BPAI and had undergone contralateral C-7-transfer more than 5 years earlier were included. Functional MRI studies were used for the investigation of long-term cerebral plasticity.

Results

The neuroimaging results suggested that the ongoing cortical remodeling process after contralateral C-7 nerve transfer could last for a long period; at least for 5 years. The motor control of the reinnervated limb may finally transfer from the ipsilateral to the contralateral hemisphere exclusively, instead of the bilateral neural network activation.

Conclusions

The authors believe that the cortical remodeling may last for a long period after peripheral rearrangement and that the successful cortical transfer is the foundation of the independent motor recovery.
Moyamoya syndrome associated with neurofibromatosis Type 1: perioperative and long-term outcome after surgical revascularization
Authors: Koss McKenzie , Scott R. Michael , Irons Mira B. , Smith Edward R. , Ullrich Nicole J.
Published: February 2013

Object

Children with neurofibromatosis Type 1 (NF1) can present with progressive arteriopathy of the branches of the internal carotid artery consistent with moyamoya syndrome. Clinical symptoms, radiographic evidence of ischemia, and the potential for disease progression may necessitate surgical revascularization to minimize the risk of stroke and progressive neurological deficits. This study aims to evaluate the presentation and surgical outcomes of these patients by reviewing clinical, radiographic, and angiographic data.

Methods

A retrospective review was conducted of clinical and radiographic records of all children with NF1 who were diagnosed with moyamoya syndrome and underwent surgical revascularization between January 1988 and April 2012 at Boston Children's Hospital.

Results

During this period, 39 patients (27 female and 12 male, ages 0.2–19.3 years) had both NF1 and moyamoya syndrome, of whom 32 underwent surgical revascularization with pial synangiosis. Of the 32 patients treated by surgical revascularization, 21 (66%) manifested ischemic symptoms and 18 (56%) had radiographic evidence of prior stroke at the time of moyamoya diagnosis. In total, 25 of 32 patients developed neurological symptoms prior to surgical intervention. Only 1 patient presented with hemorrhage. The average age at first surgery was 8.1 years (range 0.5–15.6 years). Perioperative complications in the first 7 days included stroke (n = 2), transient ischemic attack (n = 1), and infection (n = 1). Twenty-two patients had more than 6 months of follow-up, with an average clinical and radiographic postoperative follow-up period of 80.2 months (range 9.4–257.1 months). Of those patients with long-term follow-up, 21 (95%) of 22 demonstrated stable or improved neurological status despite radiographic evidence of moyamoya progression in 48% of patients.

Conclusions

Children with NF1-associated moyamoya syndrome are often diagnosed prior to development of fixed neurological deficits as a consequence of imaging studies obtained for other manifestations of NF1. The clinical, radiographic, and angiographic features in this population are comparable to primary moyamoya disease, with the exception of patients treated with cranial irradiation, who may be at greater risk for both stroke as well as perioperative complications. Despite radiographic evidence of progressive stenosis in 48% of patients, nearly all demonstrated stable or improved neurological status after surgical revascularization. Surgical revascularization for children with NF1 appears safe and is protective against further ischemic and neurological damage, with a 27-fold reduction in stroke rate.
Endoscopic cyst fenestration in the treatment of uniloculated hydrocephalus in children
Authors: El-Ghandour Nasser M. F.
Published: February 2013

Object

The treatment of uniloculated hydrocephalus is a difficult problem in pediatric neurosurgery. Definitive treatment is surgical, yet the approach remains controversial. This study evaluates the role of endoscopic cyst fenestration (ECF) in the management of this disease.

Methods

Thirty-one pediatric patients with uniloculated hydrocephalus who underwent endoscopic surgery, performed by the author, between May 1999 and December 2010 constitute the patient group for this study. The patients included 17 boys and 14 girls, with ages ranging from 5 months to 5 years (mean 22.9 months). Patients with multiloculated hydrocephalus were not included. The patients' charts were reviewed for demographic data, radiological findings, information regarding morbidity, improvement of hydrocephalus, incidence of recurrence, shunt dependency, and the need for shunt revision.

Results

Neuroepithelial cysts were the most common cause (17 cases), followed by postoperative gliosis due to previous shunt infection (9 cases), intraventricular hemorrhage (3 cases), and meningitis (2 cases). Multiplanar MRI was reliable in making the diagnosis and is indicated if CT shows disproportionate hydrocephalus. Surgical treatment included ECF (31 cases), endoscopic revision of malfunctioning preexisting shunts (9 cases), endoscopic third ventriculostomy (4 cases), and placement of a new shunt (3 cases). Endoscopic cyst fenestration was easily performed in all the cases, with devascularization of the cyst wall by coagulation to prevent recurrence. Improvement of hydrocephalus was observed in 26 cases (83.9%). Among the group of patients without prior shunts (22 cases), 3 patients (13.6%) required repeat ECF and 3 patients (13.6%) required placement of a shunt (new shunt placement). In the 9 patients with preexisting shunts, endoscopy reduced the mean rate of shunt revision from 2.7 revisions per year before fenestration to 0.25 per year after fenestration. Four of these 9 patients had multiple shunts, which could be converted to a single shunt; however, repeat ECF was necessary in all 9 patients. With a mean follow-up duration of 4.3 years, none of the patients with a prior shunt was able to become shunt-independent, whereas 86.4% of patients without a prior shunt were able to avoid shunt placement. Endoscopic complications were reversible (unilateral subdural effusion in 5 cases, minor arterial bleeding in 2 cases, CSF leakage in 1 case), and there was no death (0%).

Conclusions

Endoscopic cyst fenestration is recommended in the treatment of uniloculated hydrocephalus because it is effective, simple, minimally invasive, and associated with low morbidity and mortality rates. The fact that all previously shunt-treated patients needed repeat ECF and that none of these patients was able to become shunt-independent makes it clear that uniloculated hydrocephalus due to postoperative gliosis induced by previous shunt infection carries the worst prognosis.
Gamma Knife thalamotomy for tremor in the magnetic resonance imaging era
Authors: Kooshkabadi Ali , Lunsford L. Dade , Tonetti Daniel , Flickinger John C. , Kondziolka Douglas
Published: February 2013

Object

The surgical management of disabling tremor has gained renewed vigor with the availability of deep brain stimulation. However, in the face of an aging population of patients with increasing surgical comorbidities, noninvasive approaches for tremor management are needed. The authors' purpose was to study the technique and results of stereotactic radiosurgery performed in the era of MRI targeting.

Methods

The authors evaluated outcomes in 86 patients (mean age 71 years; number of procedures 88) who underwent a unilateral Gamma Knife thalamotomy (GKT) for tremor during a 15-year period that spanned the era of MRI-based target selection (1996–2011). Symptoms were related to essential tremor in 48 patients (19 age ≥ 80 years and 3 age ≥ 90 years), Parkinson disease in 27 patients (11 age ≥ 80 years [1 patient underwent bilateral procedures]), and multiple sclerosis in 11 patients (1 patient underwent bilateral procedures). A single 4-mm isocenter was used to deliver a maximum dose of 140 Gy to the posterior-inferior region of the nucleus ventralis intermedius. The Fahn-Tolosa-Marin clinical tremor rating scale was used to grade tremor, handwriting, and ability to drink. The median follow-up was 23 months.

Results

The mean tremor score was 3.28 ± 0.79 before and 1.81 ± 1.15 after (p < 0.0001) GKT; the mean handwriting score was 2.78 ± 0.82 and 1.62 ± 1.04, respectively (p < 0.0001); and the mean drinking score was 3.14 ± 0.78 and 1.80 ± 1.15, respectively (p < 0.0001). After GKT, 57 patients (66%) showed improvement in all 3 scores, 11 patients (13%) in 2 scores, and 2 patients (2%) in just 1 score. In 16 patients (19%) there was a failure to improve in any score. Two patients developed a temporary contralateral hemiparesis, 1 patient noted dysphagia, and 1 sustained facial sensory loss.

Conclusions

Gamma Knife thalamotomy in the MRI era was a safe and effective noninvasive surgical strategy for medically refractory tremor in the elderly or those with contraindications to deep brain stimulation or stereotactic radiofrequency (thermal) thalamotomy.
Brainstem gangliogliomas: a retrospective series
Authors: Zhang Si , Wang Xiang , Liu Xuesong , Ju Yan , Hui Xuhui
Published: February 2013

Object

The authors retrospectively analyzed data on brainstem gangliogliomas treated in their department and reviewed the pertinent literature to foster understanding of the preoperative characteristics, management, and clinical outcomes of this disease.

Methods

In 2006, the authors established a database of treated lesions of the posterior fossa. The epidemiology findings, clinical presentations, radiological investigations, pathological diagnoses, management, and prognosis for brainstem gangliogliomas were retrospectively analyzed.

Results

Between 2006 and 2012, 7 patients suffering from brainstem ganglioglioma were treated at the West China Hospital of Sichuan University. The mean age of the patients, mean duration of symptoms prior to diagnosis, and mean duration of follow-up were 28.6 years, 19.4 months, and 38.1 months, respectively. The main presentations were progressive cranial nerve deficits and cerebellar signs. Subtotal resection was achieved in 2 patients, and partial resection in 5. All tumors were pathologically diagnosed as WHO Grade I or II ganglioglioma. Radiotherapy and adjuvant chemotherapy were not administered. After 21–69 months of follow-up, patient symptoms were resolved or stable without aggravation, and MRI showed that the size of residual lesions was unchanged without progression or recurrence.

Conclusions

The diagnosis of brainstem ganglioglioma is of great importance given its favorable prognosis. The authors recommend the maximal safe resection followed by close observation without adjuvant therapy as the optimal treatment for this disease.
Successful management of an acute subdural hematoma in a patient dependent on continuous treprostinil infusion therapy
Authors: Safain Mina , Shepard Matthew , Rahal Jason , Kryzanski James , Hwang Steven , Roguski Marie , Riesenburger Ron I.
Published: February 2013

Treprostinil is a synthetic analog of prostacyclin, which is used for treatment of pulmonary arterial hypertension (PAH). Continuous subcutaneous administration of treprostinil has been proven in randomized controlled trials to improve quality of life, hemodynamics, and 5-year survival in patients with PAH. The efficacy of treprostinil has been attributed to its vasodilatory and antiplatelet effects. Unfortunately, the efficacy of treprostinil in the treatment of PAH is rapidly reversed upon cessation of the continuous infusion. Furthermore, cases of patients rapidly declining or succumbing to disease progression upon cessation of treprostinil have raised significant concern regarding discontinuation of this medication. To date, there are no reports of emergency craniotomies performed in the setting of continuous subcutaneous infusion of treprostinil. The authors report a case of a patient with PAH, treated with continuous administration of subcutaneous treprostinil as well as warfarin, who developed an acute subdural hematoma (SDH). Despite adequate INR (international normalized ratio) correction, the patient eventually underwent an emergency craniotomy for evacuation of the SDH while on continuous treprostinil administration. This case highlights the neurosurgical dilemma regarding the appropriate management of acute SDHs in patients receiving continuous treprostinil infusion.
Quality measures for the management of hydrocephalus: concepts, simulations, and preliminary field-testing
Authors: Barton Spencer E. , Campbell Jeffrey W. , Piatt Joseph H.
Published: February 2013

Object

The authors define and examine the properties of 2 new, practice-based quality measures for the management of hydrocephalus.

Methods

The Surgical Activity Rate (SAR) is defined as the number of definitive operations for the treatment of hydrocephalus performed in a neurosurgical practice over the course of a year, divided by the number of patients with hydrocephalus seen in follow-up during that year. The Revision Quotient (RQ) is defined as the number of definitive revision operations performed in a neurosurgical practice in the course of a year, divided by the number of definitive initial operations during that year for patients with newly diagnosed hydrocephalus. Using published actuarial shunt survival data, the authors conducted Monte Carlo simulations of a pediatric neurosurgical practice to illustrate the properties and interpretations of the SAR and RQ. They used data from the Kids' Inpatient Database (KID) for 2009 to calculate RQs for hospitals accounting for more than 10 admissions coded for initial CSF shunt insertions.

Results

During the initial growth phase of a simulated neurosurgical practice, the SAR approached its steady-state value much earlier than the RQ. Both measures were sensitive to doubling or halving of monthly failure rates. In the 2009 KID, 117 hospitals reported more than 10 initial shunt insertions. The weighted mean (± standard deviation) RQ for these hospitals was 1.79 ± 0.69. Among hospitals performing 50 or more initial shunt insertions, the RQ ranged between 0.71 and 3.65.

Conclusions

The SAR and RQ have attractive qualitative features as practice-based quality measures. The RQ, at least, exhibits clinically meaningful interhospital variation as applied to CSF shunt surgery. The SAR and RQ merit prospective field-testing as measures of quality in the management of childhood hydrocephalus.
Posterior interosseous nerve palsy in a child associated with recurrent dislocation of the head of the radius
Authors: Tubbs R. Shane , Griessenauer Christoph , Rizk Elias , Shoja Mohammadali M. , Pehler Stephen F. , Wellons John C. , Conklin Michael J.
Published: February 2013

Injuries to the posterior interosseous nerve (PIN) appear to be very uncommon in children. In this paper, the authors describe a 9-year-old boy with a radial malunion and radial head instability that resulted in PIN compression. Surgical decompression via transection of the overlying supinator muscle with correction of the radial deformity and instability resulted in complete return of PIN function. The clinician should be aware of anterior dislocation of the radial head as a cause of PIN injury. Based on the authors' experience, nerve decompression and correction of the bone deformity result in return of normal PIN function.
Curve progression after decompression surgery in patients with mild degenerative scoliosis
Authors: Hosogane Naobumi , Watanabe Kota , Kono Hitoshi , Saito Masashi , Toyama Yoshiaki , Matsumoto Morio
Published: February 2013

Object

The authors undertook this study to evaluate curve progression, risk factors for curve progression, and outcomes after decompression surgery in patients with degenerative lumbar scoliosis with minimal to moderate curvature.

Methods

Of 852 patients with lumbar canal stenosis treated by posterior decompression surgery, 50 patients had a lumbar curve greater than 10° at final follow-up. These patients were divided into 2 groups according to curve progression during the follow-up period: the P group (11 patients), with a curve progression of more than 5°, and the NP group (39 patients), with a curve progression of 5° or less. The authors compared preoperative parameters in these 2 groups to elucidate risk factors associated with curve progression and other surgical outcomes.

Results

The average lumbar curve progression in the total group of 50 patients was 3.4° ± 3.9° (range −2.0° to 22.0°). In the P group the average curve progression was 8.5°, and in the NP group it was 2.0°. Multivariate logistic regression analysis showed no significant association between curve progression and any of the potential risk factors evaluated (including curve magnitude, decompression method, and degenerative intervertebral disc changes). Spur formation, evaluated with the Nathan classification at the concave side of the curve, tended to be greater in the P group, although the difference was not statistically significant. There was no significant difference in revision surgery rate, and none of the patients required arthrodesis due to curve progression. Clinical outcomes, evaluated with the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire and the Scoliosis Research Society 22-question questionnaire, were also similar in the 2 groups.

Conclusions

Surgical outcomes did not deteriorate in the P group. While curve progression after decompression surgery could not be predicted from the preoperative factors considered, spur formation at the concave side of the curve may be a candidate factor. The results of this study indicate that spinal fixation to halt deformity progression is not always necessary if the patient's pathological condition derives mainly from canal stenosis.
Accuracy and complications associated with the freehand C-1 lateral mass screw fixation technique: a radiographic and clinical assessment
Authors: Hu Yong , Kepler Christopher K. , Albert Todd J. , Yuan Zhen-shan , Ma Wei-hu , Gu Yong-jie , Xu Rong-ming
Published: February 2013

Object

The aims of this study were to evaluate a large series of posterior C-1 lateral mass screws (LMSs) to determine accuracy based on CT scanning findings and to assess the perioperative complication rate related to errant screw placement.

Methods

Accuracy of screw placement was evaluated using postoperative CT scans obtained in 196 patients with atlantoaxial instability. Radiographic analysis included measurement of preoperative and postoperative CT scans to evaluate relevant anatomy and classify accuracy of instrumentation placement. Screws were graded using the following definitions: Type I, screw threads completely within the bone (ideal); Type II, less than half the diameter of the screw violates the surrounding cortex (safe); and Type III, clear violation of transverse foramen or spinal canal (unacceptable).

Results

A total of 390 C-1 LMSs were placed, but 32 screws (8.2%) were excluded from accuracy measurements because of a lack of postoperative CT scans; patients in these cases were still included in the assessment of potential clinical complications based on clinical records. Of the 358 evaluable screws with postoperative CT scanning, 85.5% of screws (Type I) were rated as being in the ideal position, 11.7% of screws (Type II) were rated as occupying a safe position, and 10 screws (2.8%) were unacceptable (Type III). Overall, 97.2% of screws were rated Type I or II. Of the 10 screws that were unacceptable on postoperative CT scans, there were no known associated neurological or vertebral artery (VA) injuries. Seven unacceptable screws erred medially into the spinal canal, and 2 patients underwent revision surgery for medial screws. In 2 patients, unilateral C-1 LMSs penetrated the C-1 anterior cortex by approximately 4 mm. Neither patient with anterior C-1 penetration had evidence of internal carotid artery or hypoglossal nerve injury. Computed tomography scanning showed partial entry of C-1 LMSs into the VA foramen of C-1 in 10 cases; no occlusion, associated aneurysm, or fistula of the VA was found. Two patients complained of postoperative occipital neuralgia. This was transient in one patient and resolved by 2 months after surgery. The second patient developed persistent neuralgia, which remained 2 years after surgery, necessitating referral to the pain service.

Conclusions

The technique for freehand C-1 LMS fixation appears to be safe and effective without intraoperative fluoroscopy guidance. Preoperative planning and determination of the ideal screw insertion point, the ideal trajectory, and screw length are the most important considerations. In addition, fewer malpositioned screws were inserted as the study progressed, suggesting a learning curve to the technique.
Ökosystemleistungen von Dauerwäldern – eine aktuelle Analyse des Waldbaus
Authors: Huth Franka , Wagner Sven
Published: February 2013

Ecosystem services and continuous cover forests – a silvicultural analysis

Current concepts of “Dauerwald” or continuous cover forestry rely on complex silvicultural strategies, which are often modified according to site conditions and the management objectives of the forest owners. The preservation of continuity and the provision of an adequate structural diversity within forest ecosystems are the common underlying principles of the different concepts of continuous cover forestry. In light of the uncertainty of the predicted climatic changes, an increased risk of disturbances and changing demands regarding the services provided by forests, it is questionable whether the silvicultural strategies currently applied in the context of continuous cover forestry (e.g. “Plenterwald”) fully embrace these changes. In order to address this issue, forest structures favoured by concepts of continuous cover forestry are assessed with respect to their direct impact on different ecosystem services (utilization, conservation, recreation). The analysis illustrates that there are currently few studies dealing with the direct link between the silvicultural strategies applied in continuous cover forests, the forest structures resulting therefrom and, subsequently, the provided ecosystem services. Although continuous cover forests deliver a wide range of ecosystem services, their concept must nevertheless be developed further, because even in continuous cover forests the equitable maximization of diverse ecosystem services cannot be realized.
Cancer screening in the United States, 2013
Authors: Smith Robert A. , Brooks Durado , Cokkinides Vilma , Saslow Debbie , Brawley Otis W.
Published: February 2013

Answer questions and earn CME/CNE

Each year the American Cancer Society (ACS) publishes a summary of its recommendations for early cancer detection, a report on data and trends in cancer screening rates, and select issues related to cancer screening. In this issue of the journal, current ACS cancer screening guidelines are summarized, as are updated guidelines on cervical cancer screening and lung cancer screening with low‐dose helical computed tomography. The latest data on the use of cancer screening from the National Health Interview Survey also are described, as are several issues related to screening coverage under the Patient Protection and Affordable Care Act of 2010. CA Cancer J Clin 2013;. © 2013 American Cancer Society.
How to Review a Scientific Article
Authors: Afroza Syeda
Published: February 2013

DOI: http://dx.doi.org/10.3329/bjch.v36i2.13567 Bangladesh J Child Health 2012; Vol 36 (2): 56-60
Use and Misuse of Antibiotics
Authors: Amin Md. Nurul
Published: February 2013

Ibrahim Cardiac Medical Journal 2011; 1(2): 7-9 DOI: http://dx.doi.org/10.3329/icmj.v1i2.13544
Serum Ferritin and Gestational Diabetes Mellitus: A Case Control Study
Authors: Islam Nilufar , Chowdhury Saleha Begum
Published: February 2013

Ibrahim Cardiac Medical Journal 2011; 1(2): 15-19 DOI: http://dx.doi.org/10.3329/icmj.v1i2.13546
Outcome of Coronary Artery Bypass Graft Surgery with Low Preoperative Ejection Fraction
Authors: Hasan Md. Sharif , Siraj Masoom , Rahman Hamidur , Amin Md. Nurul
Published: February 2013

Ibrahim Cardiac Medical Journal 2011; 1(2): 20-23 DOI: http://dx.doi.org/10.3329/icmj.v1i2.13547
Percutaneous Transvenous Mitral Commissurotomy: In-hospital Outcome of Patients with Mitral Stenosis
Authors: Taimur Syed Dawood Md. , Karim Md. Rezaul , Haq M Maksumul , Ali Md. Liaquat , Mansur Mahbub , Chowdhury Mashhud Zia , Khan Saidur Rahman
Published: February 2013

Ibrahim Cardiac Medical Journal 2011; 1(2): 24-28 DOI: http://dx.doi.org/10.3329/icmj.v1i2.13548
Ultrasonic Foetal Weight Estimation at Term in Bangladeshi Women - A Comparative Study of Eight Formulae
Authors: Mazhur Syed Iqbal , Hossain Ahmed , Afroz Laila , Chowdhury Shiuly , Amin Md. Nurul
Published: February 2013

Ibrahim Cardiac Medical Journal 2011; 1(2): 29-34 DOI: http://dx.doi.org/10.3329/icmj.v1i2.13549
Maternal and Perinatal Outcome of Twin Pregnancy in a Tertiary Hospital
Authors: Sultana Masuda , Khatun Sabera , Saha Asim Kumar , Akhter Parul , Shah Abu Bakkar Siddique
Published: February 2013

Ibrahim Cardiac Medical Journal 2011; 1(2): 35-39 DOI: http://dx.doi.org/10.3329/icmj.v1i2.13550
Cinical Presentation of Typhoid Fever
Authors: Islam Md. Shafiqul , Rahman Md. Hamidur , Karim Bazlul , Khan Md. Rakibul Haque
Published: February 2013

Ibrahim Cardiac Medical Journal 2011; 1(2): 40-45 DOI: http://dx.doi.org/10.3329/icmj.v1i2.13559
Tricuspid Valve Replacement on Beating Heart with a Bioprosthetic Valve: A case report
Authors: Rahman MZ , Biswas SK , Sharifuzzaman M , Ahmed F
Published: February 2013

Ibrahim Cardiac Medical Journal 2011; 1(2): 59-61 DOI: http://dx.doi.org/10.3329/icmj.v1i2.13563
A Case of Massive Pulmonary Embolism with Cardiac Arrest Treated with life-saving Emergency Thrombosis despite Recent Major spinal Surgery: Dealing Acute Right Ventricular Failure through Passive Leg Raising Test
Authors: Mohammad Najib
Published: February 2013

Ibrahim Cardiac Medical Journal 2011; 1(2): 62-66 DOI: http://dx.doi.org/10.3329/icmj.v1i2.13564
Curriculum Designed for an Equitable Pedagogy
Authors: Cullen Roxanne , Hill Reinhold
Published: February 2013

Rather than viewing curriculum as linear, a post-modern, learner-centered curriculum design is a spiral or recursive curriculum. Post-modernism provides a much less stable foundation upon which to build a model of student learning, a model that recognizes and even celebrates individual difference and one that is supported by research on how people learn. We propose one such curricular approach through an examination of a Bachelor of Integrative Studies program.