bluuebunny/crossref_metadata_2025_split huggingface dataset:
Localization of somatosensory function by using positron emission tomography scanning: a comparison with intraoperative cortical stimulation
Authors: Bittar Richard G. , Olivier André , Sadikot Abbas F. , Andermann Frederick , Comeau Roch M. , Cyr Martin , Peters Terrence M. , Reutens David C. 
Published: January 2008

Object
To investigate the utility of [15O]H2O positron emission tomography (PET) activation studies in the presurgical mapping of primary somatosensory cortex, the authors compared the magnitude and location of activation foci obtained using PET scanning with the results of intraoperative cortical stimulation (ICS).

Methods
The authors used PET scanning and vibrotactile stimulation (of the face, hand, or foot) to localize the primary somatosensory cortex before surgical resection of mass lesions or epileptogenic foci affecting the central area in 20 patients. With the aid of image-guided surgical systems, the locations of significant activation foci on PET scanning were compared with those of positive ICS performed at craniotomy after the patient had received a local anesthetic agent. In addition, the relationship between the magnitude and statistical significance of blood flow changes and the presence of positive ICS was examined.
In 22 (95.6%) of 23 statistically significant (p < 0.05) PET activation foci, spatially concordant sites on ICS were also observed. Intraoperative cortical stimulation was positive in 40% of the PET activation studies that did not result in statistically significant activation. In the patients showing these results, there was a clearly identifiable t-statistic peak that was spatially concordant with the site of positive ICS in the sensorimotor area. All PET activation foci with a t statistic greater than 4.75 were associated with spatially concordant sites of positive ICS. All PET activation foci with a t statistic less than 3.2 were associated with negative ICS.

Conclusions
Positron emission tomography is an accurate method for mapping the primary somatosensory cortex before surgery. The need for ICS, which requires local anesthesia, may be eliminated when PET foci with high (> 4.75) or low (< 3.20) t-statistic peaks are elicited by vibrotactile stimulation.
A genetic hypothesis for Chiari I malformation with or without syringomyelia
Authors: Speer Marcy C. , George Timothy M. , Enterline David S. , Franklin Amy , Wolpert Chantelle M. , Milhorat Thomas H. 
Published: January 2008

In several reports the authors have suggested occasional familial aggregation of syringomyelia and/or Chiari 1 malformation (CM1). Familial aggregation is one characteristic of traits that have an underlying genetic basis. The authors provide evidence for familial aggregation of CM1 and syringomyelia (CM1/S) in a large series of families, establishing that there may be a genetic component to CM1/S in at least a subset of families. The authors observed no cases of isolated familial syringomyelia in their family studies, suggesting that familial syringomyelia is more accurately classified as familial CM1 with associated syringomyelia.
These data, together with the cosegregation of the trait with known genetic syndromes, support the authors' hypothesis of a genetic basis for some CM1/S cases.
Mechanisms underlying the formation and enlargement of noncommunicating syringomyelia: experimental studies
Authors: Stoodley Marcus A. , Jones Nigel R. , Yang Liqun , Brown Christopher J. 
Published: January 2008

The pathogenesis of noncommunicating syringomyelia is unknown, and none of the existing theories adequately explains the production of cysts that occur in association with conditions other than Chiari malformation. The authors' hypothesis is that an arterial pulsation–driven perivascular flow of cerebrospinal fluid (CSF) is responsible for syrinx formation and enlargement. They investigated normal CSF flow patterns in 20 rats and five sheep by using the tracer horseradish peroxidase; the effect of reducing arterial pulse pressure was examined in four sheep by partially ligating the brachiocephalic trunk; CSF flow was examined in 78 rats with the intraparenchymal kaolin model of noncommunicating syringomyelia; and extracanalicular cysts were examined using the excitotoxic model in 38 rats.
In the normal animals there was a rapid flow of CSF from the spinal subarachnoid space into the spinal cord perivascular spaces and then into the central canal. This flow ceased when arterial pulsations were diminished. In animals with noncommunicating syringomyelia, there was rapid CSF flow into isolated and enlarged segments of central canal, even when these cysts were causing pressure damage to the surrounding spinal cord. Exitotoxic injury of the spinal cord caused the formation of extracanalicular cysts, and larger cysts were produced when this injury was combined with arachnoiditis, which impaired subarachnoid CSF flow. The results of these experiments support the hypothesis that arterial pulsation–driven perivascular fluid flow is responsible for syrinx formation and enlargement.
The “presyrinx” state: is there a reversible myelopathic condition that may precede syringomyelia?
Authors: Fischbein Nancy J. , Dillon William P. , Cobbs Charles , Weinstein Philip R. 
Published: January 2008

Object
Alteration of cerebrospinal fluid (CSF) flow has been proposed as an important mechanism leading to the development of syringomyelia. We hypothesize that a “presyrinx” condition due to potentially reversible alteration in normal CSF flow exists and that its appearance may be due to variations in the competence of the central canal of the spinal cord.

Methods
Five patients with clinical evidence of myelopathy, no history of spinal cord trauma, enlargement of the cervical spinal cord with T1 and T2 prolongation but no cavitation, evidence for altered or obstructed CSF flow, and no evidence of intramedullary tumor or a spinal vascular event underwent MR imaging before and after intervention that alleviated obstruction to CSF flow.

Results
Preoperatively, all patients demonstrated enlarged spinal cords and parenchymal T1 and T2 prolongation without cavitation. Results of magnetic resonance (MR) imaging examinations following intervention in all patients showed resolution of cord enlargement and normalization or improvement of cord signal abnormalities. In one patient with severe arachnoid adhesions who initially improved following decompression, late evolution into syringomyelia occurred in association with continued CSF obstruction.

Conclusion
Nontraumatic obstruction of the CSF pathways in the spine may result in spinal cord parenchymal T2 prolongation that is reversible following restoration of patency of CSF pathways. We refer to this MR appearance as the “presyrinx” state and stress the importance of timely intervention to limit progression to syringomyelia.
The resolution of syringohydromyelia without hindbrain herniation after posterior fossa decompression
Authors: Iskandar Bermans J. , Hedlund Gary L. , Grabb Paul A. , Oakes W. Jerry 
Published: January 2008

Object
To provide more information about this rare condition, the authors describe five cases of syringohydromyelia without hindbrain herniation. Preoperative magnetic resonance imaging with and without gadolinium-diethylenetriamine pentaacetic acid revealed no evidence of spinal cord tumor, arachnoiditis, or spinal dysraphism.

Methods
Craniocervical decompression was performed in all patients, after which there was resolution of the symptoms in the four symptomatic patients, and all five showed marked reduction in the size of the syrinx.

Conclusions
The authors hypothesize the rare occurrence of syringohydromyelia resulting from a Chiari-like pathophysiological condition but lacking a hindbrain hernia. Patients with this condition may benefit from craniocervical decompression.
Treatment of terminal syringomyelia in association with tethered cord syndrome: clinical outcomes with and without syrinx drainage
Authors: Erkan Kaan , Unal Faruk , Kiris Talat , Karalar Turan 
Published: January 2008

Object
Current use of magnetic resonance (MR) imaging has led to increased awareness of the frequency of terminal syringomyelia in patients with tethered cord syndrome. However, that the surgical treatment of terminal syringomyelia is necessary remains unclear.
In this study the authors attempted to assess the clinical impact, if any, brought after syrinx decompression on the clinical outcome of tethered cord syndrome.

Methods
They randomly assigned 30 cases of pediatric tethered cord into two treatment groups: those in whom an untethering procedure was performed (Group I) and those in whom this procedure was combined with syrinx decompression (Group II). The 1-year follow-up clinical results obtained in the two groups, in correlation with MR imaging findings, were compared to evaluate the benefit of added syrinx drainage.
Clinical follow-up evaluation revealed that surgical drainage of the syrinx, when combined with spinal cord untethering, resulted in better outcomes in terms of resolution of sensory deficits (p = 0.036) and bladder dysfunction (p = 0.05). The improvement in clinical outcome correlated with the radiologically documented resolution of the syrinx cavity; however, response rates of symptoms differed for each tethering subgroup.

Conclusions
Preliminary results of this study indicated that terminal syringomyelia should be considered as a comorbidity that contributes to the clinical outcome of patients with tethered cord syndrome. A better clinical outcome is achieved following successful decompression of the syrinx in addition to untethering the spinal cord. These findings emphasize the importance of recognizing, evaluating, and treating this pathological entity.
Interaction of fas and fas ligand in a rat 36b10 glioma model
Authors: Ryken Timothy , Frankel Bruce , Longo Sharon , Sibenaller Zita 
Published: January 2008

Object
An experimental model of the fas and fas ligand (fasL) interaction in malignant glioma was developed.

Methods
Using plasmid-based delivery, 36B10 rat glioma cells were modified to express fas (36B10-fas), and a delivery fibroblast cell line was modified to produce fasL, resulting in the FR-fasL cell line. Evaluation of fas expression was performed with flow cytometry and expression of fasL confirmed by Western blot analysis. Once the cell lines were created and partially characterized, fas-induced cytotoxicity was evaluated using an antibody-mediated assay for 36B10-fas that demonstrated significant toxicity at 24 and 48 hours. To evaluate the potential for activating the fas molecule by using cell-mediated delivery, coculture cytotoxicity studies were performed with a target cell line (36B10-fas) and effector cell line (FR-fasL). Using a series of culture ratios, increasing cytotoxicity was noted, suggesting that activation of the transfected fas receptor by fasL expression on the carrier cell was occurring.

Conclusion
Based on their experiments, the authors describe a model for evaluating the interaction of fas and fasL in a cellular model of malignant glioma.
Targeted cytotoxic gene delivery to malignant gliomas via the fibroblast growth factor receptor
Authors: Zhu Nian-Ling , Sosnowski Barbara A. , Zlokovic Berislav V. , Ong Michael , Chen Thomas C. 
Published: January 2008

Object
The use of gene therapy for the treatment of malignant gliomas has been disappointing. In an effort to increase the viral transduction efficiency in delivering cytotoxic genes to malignant gliomas, the authors have used a novel retargeting schema that redirects the adenovirus to fibroblast growth factor receptors present on the cell surface of both proliferating glioma cells and glioma endothelial cells.

Methods
Using this targeted adenovirus, the authors demonstrated an increase in expression of the luciferase marker gene in human glioma cells and glioma endothelial cells. Transduction with the herpes simplex thymidine kinase gene resulted in greater cytotoxicity when treated with ganciclovir for both cell types. This increased cytotoxity was sustained for up to 6 days after administration of ganciclovir.

Conclusions
The mechanism of cytotoxicity was determined to be apoptosis by using the terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling assay. Increasing the specificity of adenovirus targeting may be crucial to decrease the number of adenoviral vectors necessary to create adequate levels of gene transfer in malignant gliomas, thus reducing the risk of vector-related immunogenicity and toxicity, as well as increasing the overall effectiveness of cytotoxic gene therapy.
Changes in cerebral blood flow and oxygen metabolism during moderate hypothermia in patients with severe middle cerebral artery infarction
Authors: Keller Emanuela , Steiner Thorsten , Fandino Javier , Schwab Stefan , Hacke Werner 
Published: January 2008

Object
Moderate hypothermia has been reported to be effective in the treatment of postischemic brain edema. The effect of hypothermia on cerebral hemodynamics is a matter of controversial discussion in literature. Clinical studies have yet to be performed in patients with ischemic stroke after induction of hypothermia.

Methods
Measurements during mild hypothermia (33–34°C) were made in six patients with severe ischemic stroke involving the middle cerebral artery territory. Hypothermia was induced as soon as possible and maintained for 48 to 72 hours. Cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) were estimated by a new double-indicator dilution method. Measurements of CBF were made during normothermia, immediately after induction of hypothermia, at the end of hypothermia, and after rewarming. A total of 19 measurements of CBF and jugular bulb O2 saturation were made. Immediately after induction of hypothermia, CBF decreased in all patients. During late hypothermia, CBF improved in patients who survived but remained diminished in the two patients who died. Reduced CMRO2 levels were observed during all phases of hypothermia in all but one case.

Conclusions
Preliminary oberservations indicate that moderate hypothermia seems to reduce CMRO2 Immediately after induction of hypothermia, CBF may decrease in all patients. During late hypothermia CBF seems to recover in patients with good outcome but remains diminished in patients who die. Serial bedside CBF measurements with the new double-indicator dilution technique may be useful to describe cerebral hemodynamic characteristics in patients with severe ischemic stroke during hypothermia.
Expression of intracellular adhesion molecule–1 linking superoxide to mobilization of granulocytes and macrophages after periarterial blood in rat femoral artery: effect of rebamipide
Authors: Choi Jae Moon , Kim Chi Dae , Hong Ki Whan 
Published: January 2008

Object
To clarify the mechanism(s) involved in the perivascular mobilization of granulocytes and macrophages by periarterial autologous blood (PAAB) in the vicinity of the femoral artery (FA) in rats, superoxide production as well as expression of intercellular adhesion molecule–1 (ICAM-1) were determined by conducting both in vitro and in vivo experiments.

Methods
In an in vitro study, a significant amount of superoxide inhibited by diphenyleneiodonium (20 μM and 100 μM) was identified at 3 hours after application of 10% whole blood to the aortic segments, and these results were correlated with in vitro ICAM-1 expression. High expression of ICAM-1 was subsequently demonstrated in these segments at 24 hours in in vitro and in vivo studies. In the in vivo study, an increased mobilization of granulocytes paralleled with a high expression of ICAM-1 in the vessels at 24 hours after administration of PAAB to the FA and then declined. Subsequently, macrophage infiltration progressively increased at all layers throughout a period of 7 to 12 days. Pretreatment with rebamipide (100 and 300 mg kg−1 day−1, orally) significantly inhibited the expression of ICAM-1 with inhibition of mobilization of granulocyte/macrophage.

Conclusions
These findings suggest that application of PAAB to the rat FA causes superoxide-linked expression of ICAM-1 and mobilization of granulocyte and macrophages. Thus, the potential value in suppressing these variables stimulated by PAAB is indicated in therapeutic strategies for prevention and possible regression of vasospasm after subarachnoid hemorrhage.
Evidence-based analysis of odontoid fracture management
Authors: Julien Terrence D. , Frankel Bruce , Traynelis Vincent C. , Ryken Timothy C. 
Published: January 2008

Object
The management of odontoid fractures remains controversial. Evidence-based methodology was used to review the published data on odontoid fracture management to determine the state of the current practices reported in the literature.

Methods
The Medline literature (1966–1999) was searched using the keywords “odontoid,” “odontoid fracture,” and “cervical fracture” and graded using a four-tiered system. Those articles meeting selection criteria were divided in an attempt to formulate practice guidelines and standards or options for each fracture type. Evidentiary tables were constructed by treatment type.
Ninety-five articles were reviewed. Five articles for Type I, 16 for Type II, and 14 for Type III odontoid fractures met selection criteria. All studies reviewed contained Class III data (American Medical Association data classification).

Conclusions
There is insufficient evidence to establish a standard or guideline for odontoid fracture management. Given the extent of Class III evidence and outcomes reported on Type I and Type III fractures, a well-designed case-controlled study would appear to provide sufficient evidence to establish a practice guideline, suggesting that cervical immobilization for 6 to 8 weeks is appropriate management. In cases of Type II fracture, analysis of the Class III evidence suggests that both operative and nonoperative management remain treatment options. A randomized trial or serial case-controlled studies will be required to establish either a guideline or treatment standard for this fracture type.
Epidemiolgy of spinal cord injury after acute odontoid fractures
Authors: Harrop James S. , Sharan Ashwini D. , Przybylski Gregory J. 
Published: January 2008

Object
Cervical spinal cord injury (SCI) after odontoid fracture is unusual. To identify predisposing factors, the authors evaluated a consecutive series of patients who sustained SCI from odontoid fractures.

Methods
A consecutive series of 5096 admissions to the Delaware Valley Regional Spinal Cord Injury Center were reviewed, and 126 patients with neurological impairment at the C1–3 levels were identified. Seventeen patients had acute closed odontoid fractures with neurological deficit. Various parameters including demographics, mechanisms of injury, associated injuries, fracture types/displacements, and radiographic cervical canal dimensions were compared between “complete” and “incomplete” spinal cord injured–patients as well as with neurologically intact patients who had suffered odontoid fractures. There were similar demographics, mechanisms of injury, associated injuries, fracture type/displacement, and canal dimensions in patients with complete and incomplete SCIs. However, only patients with complete injury were ventilator dependent. In comparison with patients with intact spinal cords, spinal cord–injured patients were more commonly males (p = 0.011) who had sustained higher velocity injuries (p = 0.027). The computerized tomography scans of 11 of 17 neurologically impaired patients were compared with those of a random sample of 11 patients with intact spinal cords. Although the anteroposterior diameter (p = 0.028) and cross-sectional area (p = 0.0004) of the cervical spinal canal at the C–2 level were smaller in impaired patients, the displacement of the fragment was not different.

Conclusions
Odontoid fractures are an infrequent cause of SCI. Patients with these injuries typically are males who have smaller spinal canals and have sustained high velocity injuries.
Closed management of displaced Type II odontoid fractures: more frequent respiratory compromise with posteriorly displaced fractures
Authors: Przybylski Gregory J. , Harrop James S. , Vaccaro Alexander R. 
Published: January 2008

Object
Acute respiratory failure has been observed in patients after external immobilization for displaced odontoid fractures. The authors studied the frequency of respiratory deterioration in the acute management of displaced Type II odontoid fractures to identify patients at risk for respiratory failure.

Methods
The authors conducted a retrospective review of a consecutive series of 89 patients with odontoid fractures who were treated over a 5-year period to identify 53 patients with displaced Type II odontoid fractures. Patient demographics, degree of displacement, respiratory status, treatment method, and outcome were examined. Of the 32 patients with posteriorly displaced fractures, 13 experienced acute respiratory compromise, whereas only one of 21 patients with anteriorly displaced fractures had respiratory difficulties (p = 0.0032). The average posterior displacement was 6.9 mm. All 13 were initially managed using flexion traction for reduction of these fractures. Two of these patients died because of failure to emergently secure an airway during closed treatment of the fracture.

Conclusions
Frequent respiratory deterioration during acute closed reduction of posteriorly displaced Type II odontoid fractures was observed, whereas respiratory failure in patients with anteriorly displaced fractures was rare. The use of the flexed cervical position in the setting of retropharyngeal edema rather than the direction of the displacement may substantially increase the risk of respiratory failure. This may prompt early elective nasotracheal intubation during closed reduction of posteriorly displaced Type II odontoid fractures that require a flexed posture.
Use of an osteoconductive agent (Norian) in anterior surgical management of odontoid fractures
Authors: Harrop James S. , Przybylski Gregory J. 
Published: January 2008

Odontoid fractures can be successfully treated with anterior screw fixation. Odontoid fractures commonly occur in older patients who may have significant osteopenia. The authors examined the use of a bone substitute to overcome limitations encountered during a procedure in which anterior odontoid screw fixation is performed.
Two elderly patients with displaced, reducible acute odontoid fractures underwent anterior odontoid screw fixation. The intraoperative failure of the anterior vertebral cortex from osteopenic bone and failure to achieve complete contact between the dens and axis were encountered. The defects were supplemented by using the osteoconductive agent Norian. Outcome was evaluated to determine the utility of this method.
Occasional intraoperative failure of anterior odontoid screw fixation may be encountered. Supplementation of bone defects with this osteoconductive agent may facilitate successful bone union in selected patients.