bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intracranial ependymoma
Authors: Maksoud Yaser A. , Hahn Yoon S. , Engelhard Herbert H. 
Published: January 2008

Object
An intracranial ependymoma is a relatively rare but very interesting variety of glioma. In this paper, the authors compiled a review of the pathological features, imaging characteristics, and treatment strategies related to this brain tumor.

Methods
A Medline search was conducted using the term “ependymoma.” The bibliographies of papers obtained were also checked for articles and chapters that could provide additional understanding of this tumor. Malignant ependy-momas and ependymomas of the spinal cord (including myxopapillary ependymomas) were excluded from this review.

Conclusions
The posterior fossa is the most frequent site for an intracranial ependymoma. Children are frequently affected. Most authors recommend resecting as much of the tumor as is safely possible. Microscopically, ependymal tumors show both epithelial and glial features. Glial fibrillary acidic protein immunohistochemistry, therefore, helps in identifying ependymomas. Because ependymomas often recur despite surgical intervention, radiotherapy and/or radio-surgery may also play an important role in their treatment. The use of chemotherapy in the treatment of these tumors, especially in the very young, is still being studied.
Utility of preoperative functional magnetic resonance imaging for identifying language cortices in patients with vascular malformations
Authors: Pouratian Nader , Bookheimer Susan Y. , Rex David E. , Martin Neil A. , Toga Arthur W. 
Published: January 2008

Object
The goal of this study was to evaluate the utility of preoperative functional magnetic resonance (fMR) imaging in the prediction of whether a given cortical area would be deemed essential for language processing by electro-cortical stimulation mapping (ESM).

Methods
The authors studied patients with vascular malformations, specifically arteriovenous malformations (AVMs) and cavernous angiomas, in whom blood-flow patterns are not normal and in whom a perfusion-dependent mapping signal may be questionable. Ten patients were studied (seven harboring AVMs and three with cavernous angiomas). The authors used a battery of linguistic tasks, including visual object naming, word generation, auditory responsive naming, visual responsive naming, and sentence comprehension, to identify brain regions that were consistently activated across expression and comprehension linguistic tasks. In a comparison of ESM and fMR imaging activations, the authors varied the matching criteria (overlapping activations, adjacent activations, and deep activations) and the radii of influence of ESM (2.5, 5, and 10 mm) to determine the effects of these factors on the sensitivity and specificity of fMR imaging. The sensitivity and specificity of fMR imaging were dependent on the task, lobe, and matching criterion. For the population studied, the sensitivity and specificity of fMR imaging activations during expressive linguistic tasks were found to be up to 100 and 66.7%, respectively, in the frontal lobe, and during comprehension linguistic tasks up to 96.2 and 69.8%, respectively, in the temporal and parietal lobes. The sensitivity and specificity of each disease population (patients with AVMs and those with cavernous angiomas) and of individuals were consistent with those values reported for the entire population studied.

Conclusions
The authors conclude that preoperative fMR imaging is a highly sensitive preoperative planning tool for the identification of which cortical areas are essential for language and that this imaging modality may play a future role in presurgical planning for patients with vascular malformations.
Use of osteogenic protein–1 in spinal fusion: literature review and preliminary results in a prospective series of high-risk cases
Authors: Govender Preneshlin V. , Rampersaud Yoga R. , Rickards Lynda , Fehlings Michael G. 
Published: January 2008

Object
The safety and effectiveness of osteogenic protein (OP)–1 putty (recombinant human bone morphogenetic protein–7) in promoting fusion in complex spinal cases was studied in nine cases.

Methods
The authors prospectively evaluated nine patients requiring spinal fusion in whom there were medical risk factors that would inhibit osseous fusion. Intraoperatively the OP-1 putty mixed with autologous bone was placed at the fusion site. Outcome measurement instruments were used to provide information on patient demographics, comorbidities, and pain. The Short Form (SF)–36 questionnaire and Oswestry Disability Index (ODI) were administered pre- and postoperatively. All patients underwent routine radiography of the surgery site during follow-up examination.
The age of the five women and four men ranged from 21 to 74 years (mean height 1.6 m, mean weight 76.7 kg). Risk factors included mucopolysaccharide syndrome, adrenal insufficiency, rheumatoid arthritis with chronic corticosteroid use, morbid obesity, and heavy smoking. Surgery, which consisted of five cervical and four lumbar procedures, including intradural surgery in three patients, was uneventful in all cases without perioperative complication. The follow-up period ranged from 1 to 15 months (mean 5.22 months). The ODI score changed from severe disability (mean 46.89) pre-operatively to minimal and moderate disability (mean 34.56) postoperatively. The SF-36 survey showed overall improved mental and physical health scores. Fusion was present in all patients with greater than 3 months follow up.

Conclusions
The OP-1 putty appears to be safe and effective in promoting spinal arthrodesis in patients in whom adverse medical risk factors exist.
A minimally invasive approach for posterior lumbar interbody fusion
Authors: Salerni Anthony A. 
Published: January 2008

Object
Despite the technical innovations that posterior approaches for lumbar fusion have undergone, the goal of a significant reduction in the extent of dissection has remained elusive. Because extensive muscular dissection is related to both acute and chronic pain, a reproducible minimally invasive posterior approach to lumbar interbody fusion would have significant clinical value. The technical aspects of a minimally invasive approach to posterior lumbar inter-body fusion (μPLIF) with fixation involving tools developed for videoscopic discectomy will be described.

Methods
The technical description of this μPLIF procedure is based on experience gained in the first 38 cases. Outcomes categorized using a modified Macnab criteria are reported for 13 patients in whom 1 year or more of follow-up data were available.
All procedures were completed. The section of anulus fibrosus that was exposed provided access for a thorough discectomy and endplate preparation. Outcome in 11 of the 13 patients in whom outcome data were available was excellent or good. Six of these patients returned to work between 3 and 12 weeks postoperatively. Two patients suffered complications related to insertion of the interbody device.

Conclusions
This procedure involves a reproducible technique that results in a construct that is radiographically identical to that which could be expected from any standard open procedure. The minimized muscular dissection results in a tremendous improvement in postoperative mobility. All complications in this series were related to the placement of femoral cortical allograft implants. The use of a modified cement restrictor should eliminate the risk of interbody device placement.
Complications of cervical spine manipulation therapy: 5-year retrospective study in a single-group practice
Authors: Malone David G. , Baldwin Nevan G. , Tomecek Frank J. , Boxell Christopher M. , Gaede Steven E. , Covington Christopher G. , Kugler Kenyon K. 
Published: January 2008

Object
The authors report a series of 22 patients in whom major complications developed after cervical spinal manipulation therapy (CSMT). A second objective was to estimate the regional incidence of these complications and to compare it with the very low incidences reported in the literature.

Methods
During a 5-year period, practioners at a single group neurosurgical practice in Tulsa, Oklahoma, treated 22 patients, who were markedly worse during, or immediately after, CSMT. The details of these cases are reported. The 1995 US Government National Census was used to define the regional referral population for Tulsa. The published data regarding the incidence of serious CSMT-related complications and the rate of CSMTs undertaken nationally were used to estimate the expected number of CSMT-related complications in the authors' region. The number (22 cases) reported in this series was used to estimate the actual regional incidence.
Complications in the series included radiculopathy (21 cases), myelopathy (11 cases), Brown–Séquard syndrome (two cases), and vertebral artery (VA) occlusion (one case). Twenty-one patients underwent surgery. Poor outcomes were observed in three, outcome was unchanged in one, and 17 improved. The number of patients in this series exceeded the expected number for the region.

Conclusions
Cervical spinal manipulation therapy may worsen preexisting cervical disc herniation or cause disc herniation resulting in radiculopathy, myelopathy, or VA compression. In cases of cervical spondylosis, CSMT may also worsen preexisting myelopathy or radiculopathy. Manipulation of the cervical spine may also be associated with higher complication rates than previously reported.
Pediatric spinal deformities
Authors: Wiggins Gregory C. , Shaffrey Christopher I. , Abel Mark F. , Menezes Arnold H. 
Published: January 2008

Pediatric spinal deformity results from multiple conditions including congenital anomalies, neuromuscular disorders, skeletal dysplasia, and developmental disorders (idiopathic). Pediatric spinal deformities can be progressive and cause pulmonary compromise, neurological deficits, and cardiovascular compromise. The classification and treatment of these disorders have evolved since surgical treatment was popularized when Harrington distraction instrumentation was introduced.
The advent of anterior-spine instrumentation systems has challenged the concepts of length of fusion needed to arrest curvature progression. Segmental fixation revolutionized the surgical treatment of these deformities. More recently, pedicle screw–augmented segmental fixation has been introduced and promises once again to shift the standard of surgical therapy. Recent advances in thoracoscopic surgery have made this technique applicable to scoliosis surgery.
Not only has surgical treatment progressed but also the classification of different forms of pediatric deformity continues to evolve. Recently, Lenke and associates proposed a new classification for adolescent idiopathic scoliosis. This classification attempts to address some of the shortcomings of the King classification system.
In this article the authors review the literature on pediatric spinal deformities and highlight recent insights into classification, treatment, and surgery-related complications.
Atlantooccipital dislocation in children: presentation, diagnosis, and management
Authors: Steinmetz Michael P. , Lechner Roseanna M. , Anderson James S. 
Published: January 2008

Atlantooccipital dislocation (AOD) injuries are highly unstable, and usually result in significant neurological injury and death. Recently the postinjury survival period has increased. In a review of the literature the authors found 41 cases in which survival was greater than 48 hours. This is likely due to improved on-scene resuscitation, spinal immobilization, transportation, new diagnostic techniques, and a higher index of suspicion.
Diagnosis is usually made with plain cervical radiographs, but there are shortcomings associated with this modality in the pediatric population. Diagnosis is aided by high-resolution computerized tomography and magnetic resonance imaging. Infants and toddlers may undergo orthotic immobilization alone, whereas older children usually undergo early occipital cervical fusion. Those with incomplete AOD may be managed successfully with orthotic immobilization.
Evaluation of factors predicting accurate resection of high-grade gliomas by using frameless image-guided stereotactic guidance
Authors: Benveniste Ronald , Germano Isabelle M. 
Published: January 2008

Object
Frameless image-guided stereotaxy is often used in the resection of high-grade gliomas. The authors of several studies, however, have suggested that brain shift may occur intraoperatively and result in inaccurate resection. To determine the usefulness of frameless stereotactic image-guided surgery of high-grade gliomas, the authors correlated factors predictive of brain shift, such as tumor size, periventricular location, and patient age (as an indicator of brain atrophy) with the extent of resection.

Methods
Inclusion criteria included the following: 1) stereotactic volumetric craniotomy for resection of tumor; 2) histologically proven high-grade glioma; 3) preoperative magnetic resonance (MR) imaging demonstration of an enhancing portion of tumor; 4) postoperative MR imaging within 48 hours to assess the extent of resection; and 5) preoperative intention to perform gross-total resection of the enhancing tumor. Fifty-four patients met these criteria between September 1997 and November 2002. Accurate resection was considered to be indicated by a lack of nodular enhancement on postoperative Gd-enhanced MR images obtained within 48 hours of surgery.
Frameless stereotactic image-guided surgery resulted in the successful resection of 46 (85%) of 54 high-grade gliomas. Accurate resection was significantly more likely with tumors less than 30 ml in volume than with those greater than 30 ml (93 and 58%, respectively [p < 0.05]). In addition, small periventricular tumors were associated with significant less successful resection compared with nonperiventricular tumor (77 and 96%, respectively [p = 0.5]). Patient age did not affect the likelihood of successful resection.

Conclusions
Frameless image-guided stereotactic techniques can be reliably used for accurate resection of high-grade gliomas when the tumor is less than 30 ml in volume and not adjacent to the ventricular system. In cases involving tumors larger in volume or located near the ventricles, intraoperative ultrasonography or MR imaging updates should be considered.
Coregistered intraoperative ultrasonography in resection of malignant glioma
Authors: Nikas Dimitrios C. , Hartov Alexander , Lunn Karen , Rick Kyle , Paulsen Keith , Roberts David W. 
Published: January 2008

Object
The authors present their experience with coregistration of preoperative imaging data to intraoperative ultrasonography in the resection of high-grade gliomas, focusing on methodology and clinical observation.

Methods
Images were obtained preoperatively and coregistered to intraoperative hand-held ultrasound images by merging the respective imaging coordinate systems. After patient registration and imaging calibration, the authors computed the location on the magnetic resonance (MR) space of each pixel on an ultrasound image acquired in the operating room. The data were retrospectively reviewed in 11 patients with high-grade gliomas who underwent ultrasonography-assisted resection at our institution between June 2000 and December 2002.
Satisfactory coregistration of intraoperative ultrasound and preoperative MR images was accomplished in all cases. Ultrasound and MR image data were closely congruent. Preoperative setup and intraoperative use of the system were unencumbering.

Conclusions
Based on these preliminary results, intraoperative ultrasonography is an attractive neuronavigational alternative, by which a less expensive and constraining imaging technique is used to acquire updated information. Optimal intraoperative guidance can be provided by the integration of this with other imaging studies.
Cerebral Revascularization
Authors: Nussbaum Eric S. 
Published: January 2008

Despite decades of critical analysis, the precise indications for cerebral revascularization remain poorly defined. It is clear that some patients undergoing therapeutic carotid artery (CA) sacrifice for the management of unclippable intracranial aneurysms or skull base neoplasms will require revascularization to prevent or reduce the risk of cerebral infarction.4,11 Nevertheless, the decisions of when to perform this procedure and what type of bypass to undertake in these cases remain debated. The question of whether revascularization should be conducted in cases involving ischemic disease is even more controversial.1–3,5,8
This issue of Neurosurgical Focus is devoted to the topic of cerebral revascularization, assembling a collection of articles from noted experts in this field. The papers address many of the challenging and important issues yet to be defined in this controversial area.
The role of stereotactic radiosurgery for low-grade astrocytomas
Authors: Hadjipanayis Costas G. , Kondziolka Douglas , Flickinger John C. , Lunsford L. Dade 
Published: January 2008

Object
This study was conducted to examine the role of radiosurgery in the management of patients with recurrent or unresectable low-grade astrocytomas.

Methods
During a 13-year interval, 49 patients underwent stereotactic radiosurgery as part of multimodal treatment of their recurrent or unresectable low-grade astrocytomas. Thirty-seven of these patients (median age 14 years) harbored pilocytic astrocytomas and 12 patients harbored World Health Organization (WHO) Grade II fibrillary astrocytomas (median age 25 years). Tumors involved the brainstem in 22 cases, cerebellum in four, thalamus in six, temporal lobe in five, frontal lobe in four, and parietal lobe in three, as well as the hypothalamus, corpus callosum, insular cortex, optic tract, and third ventricle in one patient each. Each diagnosis was confirmed with the aid of stereotactic biopsy sampling in 17 patients, open biopsy sampling in five, partial resection in 13, and near-total resection in 14. Multimodal treatment included fractionated radiotherapy in 14 patients, stereotactic intracavitary irradiation in five, chemotherapy in two, cyst drainage in eight, ventriculoperitoneal shunt placement in five, and additional cytoreductive surgery in five. Tumor volumes ranged from 0.42 to 45.1 cm3. The median radiosurgical dose to the tumor margin was 15 Gy (range 9.6–22.5 Gy).
After radiosurgery, serial neuroimaging demonstrated complete tumor resolution in 11 patients, reduced tumor volume in 12, stable tumor volume in 10, and delayed tumor progression in 16. No procedure-related death was encountered. Forty-five of 49 patients are alive at a median follow-up period of 32 months after radiosurgery and 63 months after diagnosis. Sixteen patients participated in follow-up review for more than 60 months. Three patients died of local tumor progression.

Conclusions
Stereotactic radiosurgery is a potential alternative or adjunctive intervention in the management of selected patients with pilocytic or WHO Grade II fibrillary astrocytomas, usually performed for small-volume tumors in an attempt to avoid larger-field fractionated radiotherapy.
Magnetic resonance spectroscopy of atypical diffuse pontine masses
Authors: Krieger Mark D. , Blüml Stefan , McComb J. Gordon 
Published: January 2008

Object
Diffuse pontine gliomas in children carry a dismal prognosis, with a mean survival of less than 1 year despite therapy. The diagnosis is based on the characteristic changes demonstrated on traditional magnetic resonance (MR) imaging. A few typically MR imaging–appearing pontine masses, however, do not behave in the expected fashion, which calls the original diagnosis into question.

Methods
The authors conducted a retrospective review of data obtained in 42 children (age 6 months–13 years) in whom diffuse pontine glioma had been diagnosed at their institution. Five of these patients (12%) survived longer than expected (> 8 months). There were no differences in these patients in terms of demographics, presentation, traditional imaging findings, or treatment compared with the group as a whole. Magnetic resonance spectroscopy, however, demonstrated two distinct patterns not seen in typical diffuse pontine gliomas. In two patients elevated lipid and lactate levels were shown, with decreased levels of choline, myoinositol, and n-acetyl-aspartate (NAA). In the other patients strikingly elevated choline/creatinine ratios and myoinositol levels were observed in comparison with typical pontine tumors.

Conclusions
These MR spectroscopy patterns demonstrated in this retrospective study seem to convey prognostic information and may lead to an expansion of this diagnostic tool.
Surgical techniques for total sacrectomy and spinopelvic reconstruction
Authors: Zhang Ho-Yeol , Thongtrangan Issada , Balabhadra Raju S. V. , Murovic Judith A. , Kim Daniel H. 
Published: January 2008

The surgical management of sacral tumors requires partial or total sacrectomy and spinopelvic reconstruction. These lesions present a great surgical challenge, because most spine surgeons are unfamiliar with the techniques required for these procedures. The authors describe a step-by-step operative technique and provide several illustrations.
Total sacrectomy is performed by sequential anterior and posterior approaches that involve a rectus abdominis pull-through pedicle flap reconstruction. The anterior procedure is an intraperitoneal approach used to expose the anterior aspect of the tumor, to ligate the main tumor vessels, and to conduct an anterior partial sacrectomy. After this, the rectus abdominis myocutaneous flap, based on the inferior epigastric vessel, is prepared, and a posterior sacrectomy is performed, dividing all sacral nerve roots in the thecal sac. After complete en bloc extirpation of the sacrum with tumor, spinopelvic reconstruction and closure with a myocutaneous flap are performed. Spinopelvic reconstruction is undertaken using a modified Galveston technique or double iliac screw fixation combined with posterior lumbar segmental fixation. These provide a long lever arm within the ilium to counteract the forces exerted by the lumbar spine.
Understanding the nature of the disease as well as the biomechanics of the lumbosacral pelvic area and spinopelvic fixation will help surgeons select the appropriate treatment for sacral tumors.
Complications of revision spinal surgery
Authors: Eichholz Kurt M. , Ryken Timothy C. 
Published: January 2008

Surgical treatment for symptomatic cervical and lumbar spondylosis has become prevalent in recent years. With this increased intervention, increasing numbers of patients experience persistent symptoms and require revision spinal surgery. Although many aspects of the workup and operation are similar for both primary and revision surgery, there are special considerations that must be examined when determining if a patient is a candidate for revision surgery.
Preoperative workup should include evaluation for spinal instability. Intraoperatively, scar tissue may complicate the procedure, and care must be taken to avoid incidental durotomy. The prognosis for a revision surgery can be predicted best by the patient's outcome after the primary surgery. As with any surgical procedure, patient selection is imperative for successful outcome.