bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endoscopic endonasal surgery of the midline skull base: anatomical study and clinical considerations
Authors: Cavallo Luigi M. , Messina Andrea , Cappabianca Paolo , Esposito Felice , de Divitiis Enrico , Gardner Paul , Tschabitscher Manfred 
Published: January 2008

Object
The midline skull base is an anatomical area that extends from the anterior limit of the cranial fossa down to the anterior border of the foramen magnum. Resection of lesions involving this area requires a variety of innovative skull base approaches. These include anterior, anterolateral, and posterolateral routes, performed either alone or in combination, and resection via these routes often requires extensive neurovascular manipulation. The goals in this study were to define the application of the endoscopic endonasal approach and to become more familiar with the views and skills associated with the technique by using cadaveric specimens.

Methods
To assess the feasibility of the endonasal route for the surgical management of lesions in the midline skull base, five fresh cadaver heads injected with colored latex were dissected using a modified endoscopic endonasal approach.
Full access to the skull base and the cisternal space around it is possible with this route. From the crista galli to the spinomedullary junction, with incision of the dura mater, a complete visualization of the carotid and vertebrobasilar arterial systems and of all 12 of the cranial nerves is obtainable.

Conclusions
The major potential advantage of the endoscopic endonasal approach to the skull base is that it provides a direct anatomical route to the lesion without traversing any major neurovascular structures, obviating brain retraction. Many tumors grow in a medial-to-lateral direction, displacing structures laterally as they expand, creating natural corridors for their resection via an anteromedial approach.
Potential disadvantages of this procedure include the relatively restricted working space and the danger of an inadequate dural repair with cerebrospinal fluid (CSF) leakage and potential for meningitis resulting. These approaches often require a large opening of the dura mater over the tuberculum sellae and posterior planum sphenoidale, or retroclival space. In addition, they typically involve large intraoperative CSF leaks, which necessitate precise and effective dural closure.
Suboccipital burr holes and craniectomies
Authors: Ribas Guilherme C. , Rhoton Albert L. , Cruz Oswaldo R. , Peace David 
Published: January 2008

Object
The goal of this study was to delimit the external cranial projection of the transverse and sigmoid sinuses, and to establish initial strategic systematized burr hole sites for lateral infratentorial suboccipital approaches based on external cranial landmarks particularly related to the lambdoid, occipitomastoid, and parietomastoid sutures.

Methods
The external cranial projection of the transverse and sigmoid sinuses was studied through their external outlining obtained with the aid of multiple small perforations made from inside to outside along the inner margins of the sinuses of 50 paired temporoparietooccipital regions in 25 dried adult human skulls. The burr hole placement was studied by evaluating the supratentorial, over-the-sinuses, and infratentorial components of 1-cm-diameter openings made at strategic sites identified in the initial part of the study, which was performed in another 50 paired temporoparietooccipital regions.
The asterion and the midpoint of the inion–asterion line were found to be particularly related to the inferior half of the transverse sinus; the transverse and sigmoid sinuses' transition occurs 1 cm anteriorly to the asterion across the parietomastoid suture, and the most superior part of the sigmoid sinus is located anteriorly to the occipitomastoid suture, with its posterior margin crossing this suture posteriorly to the most superior aspect of the mastoid process, which is located at the most superior level of the mastoid notch. Burr holes made at the midpoint of the inion–asterion line, at the asterion, 1 cm anterior to the asterion, just inferiorly to the parietomastoid suture, and over the occipitomastoid suture at the most superior level of the mastoid notch are appropriate to expose the inferior half of the transverse sinus at its midpoint, the inferior half of the transverse sinus at its most lateral aspect, the transverse and sigmoid sinuses' transition, and the posterior margin of the basal aspect of the sigmoid sinus, respectively.

Conclusions
These findings allow an estimation of the transverse and sigmoid sinuses' external cranial projection. The asterion and the most posterior part of the parietomastoid suture constitute a suitable initial burr hole site at which to perform an upper or asterional suboccipital craniectomy to expose the superior aspect of the cerebellopontine angle (CPA). The occipitomastoid suture at the most superior aspect of the mastoid notch constitutes an adequate initial burr hole site at which to perform a basal suboccipital craniectomy to expose the lower portion of the CPA. The sites can be used together as initial burr hole sites to perform wide suboccipital exposures, because they already constitute natural infratentorial lateral limits.
Transpetrosal approaches to the posterior fossa
Authors: Tummala Ramachandra P. , Coscarella Ernesto , Morcos Jacques J. 
Published: January 2008

Resection of the petrous temporal bone to various degrees provides different levels of access to lesions of the posterior fossa. Although their nomenclature can be confusing, the numerous variants of the transpetrosal approaches can be classified broadly into anterior and posterior groups. The posterior transpetrosal approaches include the retro-labyrinthine, translabyrinthine, and transcochlear, whereas the ones in the anterior group are extensions of the basic middle fossa approach. Both the anterior and posterior approaches have the potential of exposing the cerebellopontine angle and the petroclival region.
The posterior approaches are based on the standard mastoidectomy and involve resection of the petrous bone to various degrees. This results in progressively increased exposure anteriorly, but comes at the expense of hearing in the translabyrinthine approach and of hearing and facial strength in the transcochlear approach.
In contrast, the middle fossa approaches spare the lateral petrous bone and involve resection of the medial petrous bone to various degrees. All of the middle fossa approaches are designed to preserve hearing. Extensions of the middle fossa approaches involve resection of bone within the Kawase rhomboid and division of the tentorium to provide exposure of the posterior fossa.
Genetic characterization of commonly used glioma cell lines in the rat animal model system
Authors: Sibenaller Zita A. , Etame Arnold B. , Ali Mushtaq M. , Barua Manali , Braun Terry A. , Casavant Thomas L. , Ryken Timothy C. 
Published: January 2008

Object
Animal models have been used extensively to discern the molecular biology of diseases and to gain insight into treatments. Nevertheless, discrepancies in the effects of treatments and procedures have been encountered during the transition from these animal models to application of the information to clinical trials in humans. To assess the genetic similarities between human gliomas and four cell lines used routinely in animal models, the authors used microarray technology to characterize the similarities and differences in gene expression.

Methods
To define the changes in gene expression, normal rat astrocytes were compared with four rat glioma cell lines (C6, 9L, F98, and RG2). The data were analyzed using two different methods: fold-change analysis and statistical analysis with t statistics. The gene products that were highlighted after intersecting the lists generated by the two methods of analysis were scrutinized against changes in gene expression reported in the literature. Tumorigenesis involves three major steps: the accumulation of genetic alterations, uncontrolled growth, and selected survival of transformed cells. The discussion of the results focuses attention on genes whose primary function is in pathways involved in glioma proliferation, infiltration, and neovascularization. A comparative microarray analysis of differentially expressed genes for four of the commonly used rat tumor cell lines is presented here.

Conclusions
Due to the variances between the cell lines and results from analyses in humans, caution must be observed in interpreting as well as in the translation of information learned from animal models to its application in human trials.
Bioinformatics approaches for detecting gene–gene and gene–environment interactions in studies of human disease
Authors: Ritchie Marylyn D. 
Published: January 2008

Neurological and mental disorders occur often, with approximately 450 million people suffering from them worldwide. Like most other common diseases, neurological disorders are hypothesized to be highly complex, with interactions among genes and risk factors playing a major role in the process. In recent years it has become obvious that for common diseases there may be more complex interactions among genes with and without strong independent main effects. These effects are more difficult to detect using traditional methodologies.
In this manuscript the author introduces the concept of epistasis and the challenges associated with detecting it. Next, she briefly mentions a number of bioinformatics approaches that have been developed to deal with this issue. Multifactor dimensionality reduction is a methodology developed specifically to deal with the challenge of detecting interaction effects in the absence of statistically detectable main effects in studies of common disorders, such as Alzheimer disease or brain cancer. Finally, the author describes the future directions for this technique and related methodologies.
Subthalamic stimulation for Parkinson disease: determination of electrode location necessary for clinical efficacy
Authors: McClelland Shearwood , Ford Blair , Senatus Patrick B. , Winfield Linda M. , Du Yunling E. , Pullman Seth L. , Yu Qiping , Frucht Steven J. , McKhann Guy M. , Goodman Robert R. 
Published: January 2008

Object
Deep brain stimulation (DBS) of the subthalamic nucleus (STN) performed using intraoperative microelectrode recording (MER) to adjust electrode placement has become a widely used treatment for patients with advanced Parkinson disease (PD). Few studies have been conducted to examine the location of implanted electrodes relative to the intended target, and even fewer have been undertaken to investigate the degree to which variations in the location of these electrodes impacts their clinical efficacy. This study was performed to examine these issues.

Methods
The authors located 52 bilaterally implanted DBS electrode tips on postoperative magnetic resonance (MR) images obtained in 26 consecutive patients. Postoperative and preoperative planning MR images were merged to determine the DBS electrode tip coordinates relative to the midcommissural point. Surgical records listed the intended target coordinates for each DBS electrode tip. Clinical outcome assessment included the Unified PD Rating Scale (UPDRS) motor score at 1 year, standardized questionnaires, and routine follow-up visits.
The mean difference between electrode tip location and intended target for all 52 electrodes was less than 2 mm in all axes. Only one electrode was farther than 3 mm from the intended target, and this was the only electrode that had to be replaced due to lack of clinical efficacy (lack of tremor suppression); its reimplantation 4 mm more medially provided excellent tremor control. High correlation coefficients indicate that the MR imaging analysis accurately determined the anatomical location of the electrode tips. Blinded videotape reviews of UPDRS motor scores comparing effects of stimulation in patients who were “on” and “off” medication identified subgroups in whom there was minimal and maximal stimulation response. Patients in these subgroups had no differences between the MR imaging–determined actual electrode tip location and its intended location. Similarly, improvements of dyskinesias and severity of symptoms encountered during the wearing-off period for the drug did not correlate with variations of electrode tip location.

Conclusions
The findings in this study lead the authors to suggest that a DBS electrode placed anywhere within a 6-mm-diameter cylinder centered at the presumed middle of the STN (based on stereotactic atlas coordinates) provides similar clinical efficacy. Future studies may be warranted to evaluate prospectively the degree to which MER modification of the anatomically and/or image-determined target improves clinical efficacy of DBS electrodes.
A brief history of endoscopic transsphenoidal surgery—from Philipp Bozzini to the First World Congress of Endoscopic Skull Base Surgery
Authors: Doglietto Francesco , Prevedello Daniel M. , Jane John A. , Han Joseph , Laws Edward R. 
Published: January 2008

Since its inception, one of the major issues in transsphenoidal surgery has been the adequate visualization of anatomical structures. As transsphenoidal surgery evolved, technical advancements improved the surgical view of the operative field and the orientation. The operating microscope replaced Cushing's headlight and Dott's lighted speculum retractor, and fluoroscopy provided intraoperative imaging. These advances led to the modern concept of micro-surgical transsphenoidal procedures in the early 1970s.
For the past 30 years the endoscope has been used for the treatment of diseases of the sinus and, more recently, in the surgical treatment of pituitary tumors. The collaboration between neurological and otorhinolaryngological surgeons has led to the development of novel surgical procedures for the treatment of various pathological conditions in the skull base.
In this paper the authors review the history of the endoscope—its technical development and its application—from the first endoscope described by Philipp Bozzini to the First World Congress of Endoscopic Skull Base Surgery held in 2005 in Pittsburgh, Pennsylvania. Specifically, in this review the history of endoscopy and its application in endonasal neurosurgery are presented.
Endoscopic third ventriculostomy for tumor-related hydrocephalus in a pediatric population
Authors: Ray Pulak , Jallo George I. , Kim R. Y. H. , Kim Bong-Soo , Wilson Sean , Kothbauer Karl , Abbott Rick 
Published: January 2008

Object
Endoscopic third ventriculostomy (ETV) has become a common alternative for managing hydrocephalus in select patients. Nevertheless, there is still controversy regarding the indications for ETV as the primary procedure, given its variable success rates. The purpose of this study is to review the authors' experience with ETV for a variety of patients.

Methods
A total of 43 children underwent ETV between July 1992 and June 2003. Their medical records, operative reports, and imaging studies, when available, were retrospectively reviewed with regard to outcome, complications, and patency rate. Treatment failure was defined as the need to place a shunt within 4 weeks of performing ETV in the patient.
There were 20 male and 23 female patients with a mean age of 9.6 years (range 8 weeks–21 years). The overall success rate was 69.8%, and the mean follow-up duration was 24.6 months. Six patients underwent eight repeated ETVs at a mean interval of 25 months, with a patency rate of 62.5% after the second procedure. Only two surgeries were aborted for anatomical reasons. The highest success rates (100% in each instance) were achieved for obstructive hydrocephalus resulting from midbrain/tectal tumor (four patients) and pineal tumor (three patients).

Conclusions
The ETV procedure is an effective management tool for obstructive hydrocephalus in children. It should be considered the primary procedure, rather than ventriculoperitoneal shunts, in carefully selected children. The success rate is dependent on the origin of the hydrocephalus.
Cowden disease and Lhermitte–Duclos disease: an update
Authors: Robinson Shenandoah , Cohen Alan R. 
Published: January 2008

Object
Cowden disease is a rare autosomal-dominant phacomatosis and cancer syndrome that is associated with Lhermitte–Duclos disease (LDD), also called dysplastic cerebellar gangliocytoma.

Methods
In this review the authors summarize the additions to the literature during the past 5 years, with emphasis on new case reports and advances in imaging and molecular biology. Adult-onset LDD is now considered pathognomonic for Cowden disease.
Approximately 220 cases of LDD have been reported. Magnetic resonance imaging in patients with LDD is often diagnostic, and imaging studies have facilitated accurate diagnosis and contributed to the improved outcome in affected patients. Cowden disease and other rare, related disorders, such as Bannayan-Riley-Ruvalcaba, Proteus, and Proteus-like syndromes, are often caused by mutations of the PTEN gene.

Conclusions
Because of the high incidence of systemic cancer in patients with Cowden disease, it is important for neurosurgeons to recognize the association between this disease and LDD and to refer affected patients for appropriate cancer screenings and interventions.
Cervical spine clearance after trauma in children
Authors: Anderson Richard C. E. , Kan Peter , Hansen Kris W. , Brockmeyer Douglas L. 
Published: January 2008

Object
Currently, no diagnostic or procedural standards exist for clearing the cervical spine in children after trauma. The purpose of this study was to determine if reeducation of nonneurosurgical personnel and initiation of a new protocol based on the National Emergency X-Radiography Utilization Study criteria could safely increase the number of pediatric cervical spines cleared of suspected injury without a neurosurgical consultation.

Methods
Data regarding cervical spine clearance in children (ages 0–18 years) after trauma protocol activation at Primary Children's Medical Center between 2001 and 2005 were collected and reviewed. Radiographic and clinical methods of clearing the cervical spine as well as the type and management of injuries were determined for two time frames: Period I (January 2001–December 2003) and Period II (January 2004–July 2005).
Between 2001 and 2003, 95% of 936 cervical spines were cleared of suspected injury by the neurosurgical service. Twenty-one ligamentous injuries (2.2%) and 12 fracture–dislocations (1.3%) were detected, with five patients requiring surgical stabilization (0.5%). Between January 2004 and July 2005, 507 (68%) of 746 cervical spines were cleared by nonneurosurgical personnel. Six ligamentous injuries (0.8%) and 10 fracture–dislocations (1.3%) were identified, with three patients (0.4%) requiring surgical stabilization. No late injuries were detected in either period.

Conclusions
The protocol used has been effective in enabling detection of cervical spine injuries in children after trauma, with the new protocol increasing by more than 60% the number of cervical spines cleared by nonneurosurgical personnel. Reeducation with establishment of the new protocols can safely facilitate clearance of the cervical spine by nonneurosurgical personnel after trauma.
Odontoid synchondrosis fractures in children
Authors: Fassett Daniel R. , McCall Todd , Brockmeyer Douglas L. 
Published: January 2008

Object
Odontoid synchondrosis fractures, although rare in the overall incidence of spinal trauma, are one of the more common fractures in young children. The goal of this study was to evaluate the demographic data, incidence of neurological deficits, treatment strategies, and outcomes in a combined series of odontoid synchondrosis fractures treated at the authors' institution and reported in other series.

Methods
In a retrospective chart review, the authors identified four odontoid synchondrosis fractures treated at their hospital since January 2000; these were combined with cases reported in six other series in the literature, yielding a total of 55 patients. Data regarding the patients' age, sex, delayed diagnosis, odontoid displacement, neurological deficits, treatment, and fusion status were collected.
The patients' ages ranged from 9 months to 7 years (mean 2.8 years), with neither sex predominating. Diagnosis was delayed in eight cases. The orientation of the odontoid fracture was reported for 36 patients, with 94% experiencing anterior displacement. Spinal cord injury (SCI) was noted in 15 patients, including 11 with complete injuries and eight with SCI at the cervicothoracic junction. Forty-two (93%) of 45 patients with fractures initially treated with external immobilization attained fusion. Eight patients were treated with surgery; four initially, with no attempt at conservative therapy, three after failed halo immobilization, and one after nonunion because of delayed diagnosis.

Conclusions
Odontoid synchondrosis fractures can be difficult to diagnose. In children younger than 7 years of age who present with neck pain or neurological deficits attributable to SCI, this fracture should be suspected. Given the high rate of fusion attained with conservative therapy, it is recommended for most synchondrosis fractures, although surgery may be warranted for individual cases.
Clinical and radiographically/neuroimaging documented outcome in transforaminal lumbar interbody fusion
Authors: Houten John K. , Post Nicholas H. , Dryer Joseph W. , Errico Thomas J. 
Published: January 2008

Object
Although transforaminal lumbar interbody fusion (TLIF) is an increasingly popular surgical technique, there are a limited number of studies in which investigators have stratified outcome data with respect to surgical indications or documented radiographically proven and clinical results with respect to disc space height (DSH). The authors conducted a study to evaluate the long-term outcomes after TLIF with respect to surgical indication and radiographic/neuroimaging results.

Methods
Thirty-three consecutive TLIF-treated patients underwent follow-up investigation for a mean of 37 months. Isthmic spondylolysis was present in eight patients, recurrent disc herniation in 14, and degenerative disc disease (DDD) in 11. The operative technique involved the placement of interbody structural allograft, pedicle screw instrumentation, and morcellized autograft in the anterior interbody space and the contralateral intertransverse gutter. Surgery was performed at L4–5 in 16 patients, L5–S1 in 14, L3–4 in two, and both L4–5 and L5–S1 in one patient.
Preoperative symptoms were back pain (in 91% of cases), leg pain (in 94%), sensory loss (in 67%), and motor deficits (in 30%). Postoperatively, back pain was improved in 67% of the patients, unchanged in 27%, and worsened in 7%. Leg pain improved in 80% of patients, was unchanged in 10%, and worsened in 10%. Outcome, as measured using the Prolo Functional and Economic Scales, improved from a score of 4.9 to 7. In patients with spondylolysis and recurrent disc herniation outcomes were better than in those with DDD only. There was no correlation of outcome with symptom duration, patient age, or level of surgery. In an independent review of pre- and late postoperative radiographs no significant differences in lordosis angles, Cobb angles, or DSHs were found. Fusion occurred in all cases.

Conclusions
The TLIF procedure was associated with good clinical outcomes and a high fusion rate but no change in the DSH. Patients who present with spondylolysis and recurrent herniations experience better outcome than those with degenerative disease alone.