bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calgary Shunt Protocol, an adaptation of the Hydrocephalus Clinical Research Network shunt protocol, reduces shunt infections in children
Authors: Yang Michael M. H. , Hader Walter , Bullivant Kelly , Brindle Mary , Riva-Cambrin Jay 
Published: February 2019

OBJECTIVEThe shunt protocol developed by the Hydrocephalus Clinical Research Network (HCRN) was shown to significantly reduce shunt infections in children. However, its effectiveness had not been validated in a non-HCRN, small- to medium-volume pediatric neurosurgery center. The present study evaluated whether the 9-step Calgary Shunt Protocol, closely adapted from the HCRN shunt protocol, reduced shunt infections in children.METHODSThe Calgary Shunt Protocol was prospectively applied at Alberta Children’s Hospital from May 23, 2013, to all children undergoing any shunt procedure. The control cohort consisted of children undergoing shunt surgery between January 1, 2009, and the implementation of the Calgary Shunt Protocol. The primary outcome was the strict HCRN definition of shunt infection. Univariate analyses of the protocol, individual elements within, and known confounders were performed using Student t-test for measured variables and chi-square tests for categorical variables. Multivariable logistic regression was performed using stepwise analysis.RESULTSTwo-hundred sixty-eight shunt procedures were performed. The median age of patients was 14 months (IQR 3–61), and 148 (55.2%) were male. There was a significant absolute risk reduction of 10.0% (95% CI 3.9%–15.9%) in shunt infections (12.7% vs 2.7%, p = 0.004) after implementation of the Calgary Shunt Protocol. In univariate analyses, chlorhexidine was associated with fewer shunt infections than iodine-based skin preparation solution (4.1% vs 12.3%, p = 0.02). Waiting ≥ 20 minutes between receiving preoperative antibiotics and skin incision was also associated with a reduction in shunt infection (4.5% vs 14.2%, p = 0.007). In the multivariable analysis, only the overall protocol independently reduced shunt infections (OR 0.19 [95% CI 0.06–0.67], p = 0.009), while age, etiology, procedure type, ventricular catheter type, skin preparation solution, and time from preoperative antibiotics to skin incision were not significant.CONCLUSIONSThis study externally validates the published HCRN protocol for reducing shunt infection in an independent, non-HCRN, and small- to medium-volume pediatric neurosurgery setting. Implementation of the Calgary Shunt Protocol independently reduced shunt infection risk. Chlorhexidine skin preparation and waiting ≥ 20 minutes between administration of preoperative antibiotic and skin incision may have contributed to the protocol’s quality improvement success.
Impact of total propofol dose during spinal surgery: anesthetic fade on transcranial motor evoked potentials
Authors: Ushirozako Hiroki , Yoshida Go , Kobayashi Sho , Hasegawa Tomohiko , Yamato Yu , Yasuda Tatsuya , Banno Tomohiro , Arima Hideyuki , Oe Shin , Mihara Yuki , Togawa Daisuke , Matsuyama Yukihiro 
Published: February 2019

OBJECTIVEIntraoperative neuromonitoring may be valuable for predicting postoperative neurological complications, and transcranial motor evoked potentials (TcMEPs) are the most reliable monitoring modality with high sensitivity. One of the most frequent problems of TcMEP monitoring is the high rate of false-positive alerts, also called “anesthetic fade.” The purpose of this study was to clarify the risk factors for false-positive TcMEP alerts and to find ways to reduce false-positive rates.METHODSThe authors analyzed 703 patients who underwent TcMEP monitoring under total intravenous anesthesia during spinal surgery within a 7-year interval. They defined an alert point as final TcMEP amplitudes ≤ 30% of the baseline. Variations in body temperature (maximum − minimum body temperature during surgery) were measured. Patients with false-positive alerts were classified into 2 groups: a global group with alerts observed in 2 or more muscles of the upper and lower extremities, and a focal group with alerts observed in 1 muscle.RESULTSFalse-positive alerts occurred in 100 cases (14%), comprising 60 cases with global and 40 cases with focal alerts. Compared with the 545 true-negative cases, in the false-positive cases the patients had received a significantly higher total propofol dose (1915 mg vs 1380 mg; p < 0.001). In the false-positive cases with global alerts, the patients had also received a higher mean propofol dose than those with focal alerts (4.5 mg/kg/hr vs 4.2 mg/kg/hr; p = 0.087). The cutoff value of the total propofol dose for predicting false-positive alerts, with the best sensitivity and specificity, was 1550 mg. Multivariate logistic analysis revealed that a total propofol dose > 1550 mg (OR 4.583; 95% CI 2.785–7.539; p < 0.001), variation in body temperature (1°C difference; OR 1.691; 95% CI 1.060–2.465; p < 0.01), and estimated blood loss (500-ml difference; OR 1.309; 95% CI 1.155–1.484; p < 0.001) were independently associated with false-positive alerts.CONCLUSIONSIntraoperative total propofol dose > 1550 mg, larger variation in body temperature, and greater blood loss are independently associated with false-positive alerts during spinal surgery. The authors believe that these factors may contribute to the false-positive global alerts that characterize anesthetic fade. As it is necessary to consider multiple confounding factors to distinguish false-positive alerts from true-positive alerts, including variation in body temperature or ischemic condition, the authors argue the importance of a team approach that includes surgeons, anesthesiologists, and medical engineers.
Outcomes in different age groups with primary Ewing sarcoma of the spine: a systematic review of the literature
Authors: Berger Garrett K. , Nisson Peyton L. , James Whitney S. , Kaiser Kristen N. , Hurlbert R. John 
Published: February 2019

OBJECTIVEEwing sarcoma (ES) is among the most prevalent of bone sarcomas in young people. Less often, it presents as a primary lesion of the spine (5%–15% of patients with ES).METHODSA systematic literature search was performed, querying several scientific databases per PRISMA guidelines. Inclusion criteria specified all studies of patients with surgically treated ES located in the spine. Patient age was categorized into three groups: 0–13 years (age group 1), 14–20 years (age group 2), and > 21 (age group 3).RESULTSEighteen studies were included, yielding 28 patients with ES of the spine. Sixty-seven percent of patients experienced a favorable outcome, with laminectomies representing the most common (46%) of surgical interventions. One-, 2-, and 5-year survival rates were 82% (n = 23), 75% (n = 21), and 57% (n = 16), respectively. Patients in age group 2 experienced the greatest mortality rate (75%) compared to age group 1 (9%) and age group 3 (22%). The calculated relative risk score indicated patients in age group 2 were 7.5 times more likely to die than other age groups combined (p = 0.02).CONCLUSIONSPrimary ES of the spine is a rare, debilitating disease in which the role of surgery and its impact on one’s quality of life and independence status has not been well described. This study found the majority of patients experienced a favorable outcome with respect to independence status following surgery and adjunctive treatment. An increased risk of recurrence and death was also present among the adolescent age group (14–20 years).
3-Tesla MRI of deep brain stimulation patients: safety assessment of coils and pulse sequences
Authors: Boutet Alexandre , Hancu Ileana , Saha Utpal , Crawley Adrian , Xu David S. , Ranjan Manish , Hlasny Eugen , Chen Robert , Foltz Warren , Sammartino Francesco , Coblentz Ailish , Kucharczyk Walter , Lozano Andres M. 
Published: February 2019

OBJECTIVEPhysicians are more frequently encountering patients who are treated with deep brain stimulation (DBS), yet many MRI centers do not routinely perform MRI in this population. This warrants a safety assessment to improve DBS patients’ accessibility to MRI, thereby improving their care while simultaneously providing a new tool for neuromodulation research.METHODSA phantom simulating a patient with a DBS neuromodulation device (DBS lead model 3387 and IPG Activa PC model 37601) was constructed and used. Temperature changes at the most ventral DBS electrode contacts, implantable pulse generator (IPG) voltages, specific absorption rate (SAR), and B1+rms were recorded during 3-T MRI scanning. Safety data were acquired with a transmit body multi-array receive and quadrature transmit-receive head coil during various pulse sequences, using numerous DBS configurations from “the worst” to “the most common.”In addition, 3-T MRI scanning (T1 and fMRI) was performed on 41 patients with fully internalized and active DBS using a quadrature transmit-receive head coil. MR images, neurological examination findings, and stability of the IPG impedances were assessed.RESULTSIn the phantom study, temperature rises at the DBS electrodes were less than 2°C for both coils during 3D SPGR, EPI, DTI, and SWI. Sequences with intense radiofrequency pulses such as T2-weighted sequences may cause higher heating (due to their higher SAR). The IPG did not power off and kept a constant firing rate, and its average voltage output was unchanged. The 41 DBS patients underwent 3-T MRI with no adverse event.CONCLUSIONSUnder the experimental conditions used in this study, 3-T MRI scanning of DBS patients with selected pulse sequences appears to be safe. Generally, T2-weighted sequences (using routine protocols) should be avoided in DBS patients. Complementary 3-T MRI phantom safety data suggest that imaging conditions that are less restrictive than those used in the patients in this study, such as using transmit body multi-array receive coils, may also be safe. Given the interplay between the implanted DBS neuromodulation device and the MRI system, these findings are specific to the experimental conditions in this study.
Nucleus basalis of Meynert neuronal activity in Parkinson’s disease
Authors: Lee Darrin J. , Milosevic Luka , Gramer Robert , Sasikumar Sanskriti , Al-Ozzi Tameem M. , De Vloo Philippe , Dallapiazza Robert F. , Elias Gavin J. B. , Cohn Melanie , Kalia Suneil K. , Hutchison William D. , Fasano Alfonso , Lozano Andres M. 
Published: February 2019

OBJECTIVENeuronal loss within the cholinergic nucleus basalis of Meynert (nbM) correlates with cognitive decline in dementing disorders such as Alzheimer’s disease and Parkinson’s disease (PD). In nonhuman primates, the nbM firing pattern (5–40 Hz) has also been correlated with working memory and sustained attention. In this study, authors performed microelectrode recordings of the globus pallidus pars interna (GPi) and the nbM immediately prior to the implantation of bilateral deep brain stimulation (DBS) electrodes in PD patients to treat motor symptoms and cognitive impairment, respectively. Here, the authors evaluate the electrophysiological properties of the nbM in patients with PD.METHODSFive patients (4 male, mean age 66 ± 4 years) with PD and mild cognitive impairment underwent bilateral GPi and nbM DBS lead implantation. Microelectrode recordings were performed through the GPi and nbM along a single trajectory. Firing rates and burst indices were characterized for each neuronal population with the patient at rest and performing a sustained-attention auditory oddball task. Action potential (AP) depolarization and repolarization widths were measured for each neuronal population at rest.RESULTSIn PD patients off medication, the authors identified neuronal discharge rates that were specific to each area populated by GPi cells (92.6 ± 46.1 Hz), border cells (34 ± 21 Hz), and nbM cells (13 ± 10 Hz). During the oddball task, firing rates of nbM cells decreased (2.9 ± 0.9 to 2.0 ± 1.1 Hz, p < 0.05). During baseline recordings, the burst index for nbM cells (1.7 ± 0.6) was significantly greater than those for GPi cells (1.2 ± 0.2, p < 0.05) and border cells (1.1 ± 0.1, p < 0.05). There was no significant difference in the nbM burst index during the oddball task relative to baseline (3.4 ± 1.7, p = 0.20). With the patient at rest, the width of the depolarization phase of APs did not differ among the GPi cells, border cells, and nbM cells (p = 0.60); however, during the repolarization phase, the nbM spikes were significantly longer than those for GPi high-frequency discharge cells (p < 0.05) but not the border cells (p = 0.20).CONCLUSIONSNeurons along the trajectory through the GPi and nbM have distinct firing patterns. The profile of nbM activity is similar to that observed in nonhuman primates and is altered during a cognitive task associated with cholinergic activation. These findings will serve to identify these targets intraoperatively and form the basis for further research to characterize the role of the nbM in cognition.
Minicraniotomy with a subgaleal pocket for the treatment of subdural fluid collections in infants
Authors: Palmer Angela W. , Albert Gregory W. 
Published: February 2019

OBJECTIVEVarious surgical techniques have been described to treat subdural fluid collections in infants, including transfontanelle aspiration, burr holes, subdural drain, subduroperitoneal shunt, and minicraniotomy. The purpose of this study was to describe a modification of the minicraniotomy technique that avoids the implantation of external drainage catheters and potentially carries a higher success rate.METHODSIn this retrospective study, the authors describe 11 cases involving pediatric patients who underwent parietal minicraniotomies for the evacuation of subdural fluid collections. In contrast to cases previously described in the literature, no patient received a drain; instead, a subgaleal pocket was created such that the fluid could flow from the subdural to the subgaleal space. Preoperative and postoperative data were reviewed, including neurological examination findings, radiological findings, complications, hospital length of stay, and findings on follow-up examinations and imaging. The primary outcome was failure of the treatment strategy, defined as an increase in subdural fluid collection requiring further intervention.RESULTSEleven patients (8 boys and 3 girls, median age 4.5 months) underwent the described procedure. Eight of the patients had complete resolution of the subdural collection on follow-up imaging, and 2 had improvement. One patient had a new subdural collection due to a second injury. Only 1 patient underwent aspiration and subsequent surgical repair of a pseudomeningocele after the initial surgery. Notably, no patients required subduroperitoneal shunt placement.CONCLUSIONSThe authors describe a new surgical option for subdural fluid collections in infants that allows for more aggressive evacuation of the subdural fluid and eliminates the need for a drain or shunt placement. Further work with more patients and direct comparison to other alternative therapies is necessary to fully evaluate the efficacy and safety of this new technique.
Neurosurgical treatment of pediatric pleomorphic xanthoastrocytomas: long-term follow-up of a single-institution, consecutive series of 12 patients
Authors: Lundar Tryggve , Due-Tønnessen Bernt Johan , Frič Radek , Krossnes Bård , Brandal Petter , Stensvold Einar , Due-Tønnessen Paulina 
Published: February 2019

OBJECTIVEThe authors conducted a study to delineate the long-term results of the surgical treatment of pediatric pleomorphic xanthoastrocytomas (PXAs).METHODSAll consecutive children and adolescents (0–20 years) who underwent primary tumor resection for a PXA during the years 1972–2015 were included in this retrospective study on surgical morbidity, mortality rate, academic achievement, and/or work participation. Gross motor function and activities of daily living were scored according to the Barthel Index.RESULTSOf the 12 patients, 8 patients were in the 1st decade of life and 4 in the 2nd. The male/female ratio was 6:6. No patient was lost to follow-up. One patient presented with severe progressive tumor disease and died within 3 months after repeated resection. Another child died 3 days following a second surgical procedure involving gross-total resection (GTR) 8 years after the initial operation. The other 10 patients were alive at the latest follow-up when they reached the median age of 34 years (range 11–60 years). The median follow-up duration was 22 years (range 2–41 years). Barthel Index score was 100 in all 10 survivors. A total 18 tumor resections were performed. Five patients underwent a second tumor resection after MRI/CT confirmed recurrent tumor disease, from 6 months up to 17 years after the initial operation. Only one of our patients received adjuvant therapy: a 19-year-old male who underwent resection (GTR) for a right-sided temporal tumor in 1976. This particular tumor was originally classified as astrocytoma WHO grade IV, and postoperative radiotherapy (54 Gy) was given. The histology was reclassified to that of a PXA. Seven of 8 children whose primary tumor resection was performed more than 20 years ago are alive as of this writing—i.e., 88% observed 20-year survival. These are long-term survivors with good clinical function and all are in full- or part-time work.CONCLUSIONSPediatric patients with PXA can be treated with resection alone with rewarding results. Recurrences are not uncommon, but repeated surgery is well tolerated and should be considered in low-grade cases before adjuvant therapy is implemented. Follow-up including repeated MRI is important during the first postoperative years, since individual patients may have a more aggressive tumor course.
Subtotal resection of cervical schwannomas and growth rate of residual tumors
Authors: Ryu Sung Mo , Lee Sun-Ho , Lee Kyung Min , Eoh Whan , Kim Eun-Sang 
Published: February 2019

OBJECTIVEThe objective of this study was to elucidate the features and surgical outcomes of cervical schwannomas.METHODSThe authors retrospectively reviewed the records of 90 patients who underwent surgically treated cervical schwannomas from January 1995 to December 2017, with an emphasis on MRI findings such as tumor location, tumor size, extent of tumor resection, and growth of a residual tumor.RESULTSThis study included 51 men (56.7%) and 39 women (43.3%) with a mean age of 44.5 years (range 7–77 years). Dumbbell-shaped tumors comprised 62 (68.9%) of 90 cases and gross-total resection (GTR) was achieved in 59 (65.6%) of 90 cases. All nondumbbell tumors (n = 28) underwent GTR. Only 1 case of recurrence in the GTR group showed a gradual increase in size (by 8.9 mm) during the 150-month follow-up period. For the regrowth patients in the subtotal resection group, the mean percentage increase in tumor size was 47.5% ± 33.1% and the mean growth rate was 5.8 ± 4.6 mm/year during the 20.3-month follow-up period. However, the size of residual tumor spontaneously decreased by a mean of 8.3% ± 11.1% during the 48.4-month follow-up period in the nonregrowth group.CONCLUSIONSThese findings suggested that frequent MRI follow-up examinations are required for residual schwannomas in the cervical spine for at least 2 years, and continuous MRI follow-ups are also required thereafter.
Astronaut Michael Collins, Apollo 8, and the anterior cervical fusion that changed the history of human spaceflight
Authors: Menger Richard , Wolf Michael , Thakur Jai Deep , Nanda Anil , Martino Anthony 
Published: February 2019

In 1961, President John F. Kennedy declared that the United States would send a man to the moon and safely bring him home before the end of the decade. Astronaut Michael Collins was one of those men. He flew to the moon on the historic flight of Apollo 11 while Neil Armstrong and Buzz Aldrin walked on its surface. However, this was not supposed to be the case.Astronaut Collins was scheduled to fly on Apollo 8. While training, in 1968, he started developing symptoms of cervical myelopathy. He underwent evaluation at Wilford Hall Air Force Hospital in San Antonio and was noted to have a C5–6 disc herniation and posterior osteophyte on myelography. Air Force Lieutenant General (Dr.) Paul W. Myers performed an anterior cervical discectomy with placement of iliac bone graft. As a result, Astronaut James Lovell took his place on Apollo 8 flying the uncertain and daring first mission to the moon. This had a cascading effect on the rotation of astronauts, placing Michael Collins on the Apollo 11 flight that first landed men on the moon. It also placed Astronaut James Lovell in a rotation that exposed him to be the Commander of the fateful Apollo 13 flight.Here, the authors chronicle the history of Astronaut Collins’ anterior cervical surgery and the impact of his procedure on the rotation of astronaut flight selection, and they review the pivotal historic nature of the Apollo 8 spaceflight. The authors further discuss the ongoing issue of cervical disc herniation among astronauts.
Validation of a methodology for neuro-urological and lumbosacral stimulation studies in domestic pigs: a humanlike animal model
Authors: Guiho Thomas , Azevedo-Coste Christine , Guiraud David , Delleci Claire , Capon Grégoire , Delgado-Piccoli Natalia , Bauchet Luc , Vignes Jean-Rodolphe 
Published: February 2019

OBJECTIVESpinal cord injuries (SCIs) result in loss of movement and sensory feedback, but also organ dysfunction. Nearly all patients with complete SCI lose bladder control and are prone to kidney failure if intermittent catheterization is not performed. Electrical stimulation of sacral spinal roots was initially considered to be a promising approach for restoring continence and micturition control, but many patients are discouraged by the need for surgical deafferentation as it could lead to a loss of sensory functions and reflexes. Nevertheless, recent research findings highlight the renewed interest in spinal cord stimulation (SCS). It is thought that synergic recruitment of spinal fibers could be achieved by stimulating the spinal neural networks involved in regulating physiological processes. Paradoxically, most of these recent studies focused on locomotor issues, while few addressed visceral dysfunction. This could at least partially be attributed to the lack of methodological tools. In this study, the authors aim to fill this gap by presenting a comprehensive method for investigating the potential of SCS to restore visceral functions in domestic pigs, a large-animal model considered to be a close approximation to humans.METHODSThis methodology was tested in 7 female pigs (Landrace pig breed, 45–60 kg, 4 months old) during acute experiments. A combination of morphine and propofol was used for anesthesia when transurethral catheterization and lumbosacral laminectomy (L4–S4) were performed. At the end of the operation, spinal root stimulation (L6–S5) and urodynamic recordings were performed to compare the evoked responses with those observed intraoperatively in humans.RESULTSNervous excitability was preserved despite long-term anesthesia (mean 8.43 ± 1.5 hours). Transurethral catheterization and conventional laminectomy were possible while motor responses (gluteus muscle monitoring) were unaffected throughout the procedure. Consistent detrusor (approximately 25 cm H2O) and sphincter responses were obtained, whereas spinal root stimulation elicited detrusor and external urethral sphincter co-contractions similar to those observed intraoperatively in humans.CONCLUSIONSPigs represent an ideal model for SCS studies aimed at visceral function investigation and restoration because of the close similarities between female domestic pigs and humans, both in terms of anatomical structure and experimental techniques implemented. This article provides methodological keys for conducting experiments with equipment routinely used in clinical practice.