bluuebunny/crossref_metadata_2025_split huggingface dataset:
A proposed radiosurgery-based grading system for arteriovenous malformations
Authors: Pollock Bruce E. , Flickinger John C. 
Published: May 2009

Object. Radiosurgery is an effective treatment strategy for properly selected patients harboring arteriovenous malformations (AVMs). Grading scales that are currently used to predict patient outcomes after AVM resection are unreliable tools for the prediction of the results of AVM radiosurgery.
Methods. A grading system was developed to predict outcomes following AVM radiosurgery, based on the multivariate analysis of data obtained in 220 patients treated between 1987 and 1991 (Group 1). The dependent variable in all analyses was excellent patient outcome (complete AVM obliteration without any new neurological deficit). The grading scale was tested on a separate set of 136 patients with AVMs treated between 1990 and 1996 at a different center (Group 2).
One hundred twenty-one (55%) of 220 Group 1 patients had excellent outcomes. Multivariate analysis identified five variables related to excellent patient outcomes: AVM volume (p = 0.001), patient age (p < 0.001), AVM location (p < 0.001), previous embolization (p = 0.02), and number of draining veins (p = 0.001). Regression analysis modeling permitted removal of two significant variables (previous embolization and number of draining veins) and resulted in the following equation to predict patient outcomes after AVM radiosurgery: AVM score = (0.1)(AVM volume in cm3) + (0.02)(patient age in years) + (0.3)(location of lesion: frontal or temporal) = 0; parietal, occipital, intraventricular, corpus callosum, cerebellar = 1; or basal ganglia, thalamic, or brainstem = 2). Seventy-nine (58%) of 136 Group 2 patients had excellent outcomes. All variables in the model remained significant for the Group 2 patients: AVM volume (p = 0.01), patient age (p = 0.01), and AVM location (p < 0.001). Testing of the entire model on the Group 2 patients demonstrated that the AVM score could be used to predict patient outcomes after radiosurgery (p < 0.0001). All patients with an AVM score of 1 or lower had an excellent outcome compared with only 39% of patients with an AVM score higher than 2. The Spetzler—Martin grade (p = 0.13), the K index (p = 0.26), and the obliteration prediction index (p = 0.21) did not correlate with excellent patient outcomes.
Conclusions. Despite significant differences in preoperative patient characteristics and dose prescription guidelines at the two centers, the proposed AVM grading system strongly correlated with patient outcomes after single-session radiosurgery for both patient groups. Although further testing of this model by independent centers using prospective methodology is still required, this system allows a more accurate prediction of outcomes from radiosurgery to guide choices between surgical and radiosurgical management for individual patients with AVMs.
Effect of apolipoprotein E genotype on hematoma volume after trauma
Authors: Liaquat Imran , Dunn Laurence T. , Nicoll James A. R. , Teasdale Graham M. , Norrie John D. 
Published: May 2009

Object. The apolipoprotein E-ϵ4 (APOE-ϵ4) allele is associated with poor outcome after head injury and spontaneous intracerebral hemorrhage (SICH). The aims of this study were to determine if patients in whom one or more APOE-ϵ4 alleles are present are more likely to sustain intracranial mass lesions after head injury and to determine whether there is an isoform-specific effect on the size of the intracranial hematoma.
Methods. The authors performed a computerized volumetric analysis of 142 hematomas visible on computerized tomography (CT) scans obtained in 129 patients. The APOE genotype was determined by subjecting buccal smear samples to polymerase chain reaction and restriction enzyme digestion.
Allele frequencies were similar in head-injured patients with and without intracranial hematomas (p = 0.36). Univariate analysis revealed that in those patients with one or more APOE-ϵ4 alleles hematoma volume was greater (cube root—transformed values) than that found in patients without the APOE-ϵ4 allele (3.1 cm compared with 2.5 cm, p = 0.0039). The results of univariate analysis also suggested significant effects of patient age, injury severity (mild, moderate, or severe according to admission Glasgow Coma Scale scores) and hematoma location (extraaxial, intraaxial, or both) on hematoma volume. The mechanism of injury (assault, fall, or other) was marginally associated with hematoma volume (p = 0.052). Time from injury to CT scan, hypoxia, and hypotension had no significant effect on hematoma volume. The results of multiple linear regression analysis showed that the presence of an APOE-ϵ4 allele and an extraaxial hematoma location were independent predictors of hematoma volume, after adjusting for patient age, hours between injury and CT scan, injury severity, and injury mechanism.
Conclusions. Larger hematomas were found in head-injured patients with one or more APOE-ϵ4 alleles than in patients without the allele. This may contribute to the poorer outcomes observed in these patients.
Progressive hemorrhage after head trauma: predictors and consequences of the evolving injury
Authors: Oertel Matthias , Kelly Daniel F. , McArthur David , Boscardin W. John , Glenn Thomas C. , Lee Jae Hong , Gravori Tooraj , Obukhov Dennis , McBride Duncan Q. , Martin Neil A. 
Published: May 2009

Object. Progressive intracranial hemorrhage after head injury is often observed on serial computerized tomography (CT) scans but its significance is uncertain. In this study, patients in whom two CT scans were obtained within 24 hours of injury were analyzed to determine the incidence, risk factors, and clinical significance of progressive hemorrhagic injury (PHI).
Methods. The diagnosis of PHI was determined by comparing the first and second CT scans and was categorized as epidural hematoma (EDH), subdural hematoma (SDH), intraparenchymal contusion or hematoma (IPCH), or subarachnoid hemorrhage (SAH). Potential risk factors, the daily mean intracranial pressure (ICP), and cerebral perfusion pressure were analyzed. In a cohort of 142 patients (mean age 34 ± 14 years; median Glasgow Coma Scale score of 8, range 3–15; male/female ratio 4.3:1), the mean time from injury to first CT scan was 2 ± 1.6 hours and between first and second CT scans was 6.9 ± 3.6 hours. A PHI was found in 42.3% of patients overall and in 48.6% of patients who underwent scanning within 2 hours of injury. Of the 60 patients with PHI, 87% underwent their first CT scan within 2 hours of injury and in only one with PHI was the first CT scan obtained more than 6 hours postinjury. The likelihood of PHI for a given lesion was 51% for IPCH, 22% for EDH, 17% for SAH, and 11% for SDH. Of the 46 patients who underwent craniotomy for hematoma evacuation, 24% did so after the second CT scan because of findings of PHI. Logistic regression was used to identify male sex (p = 0.01), older age (p = 0.01), time from injury to first CT scan (p = 0.02), and initial partial thromboplastin time (PTT) (p = 0.02) as the best predictors of PHI. The percentage of patients with mean daily ICP greater than 20 mm Hg was higher in those with PHI compared with those without PHI. The 6-month postinjury outcome was similar in the two patient groups.
Conclusions. Early progressive hemorrhage occurs in almost 50% of head-injured patients who undergo CT scanning within 2 hours of injury, it occurs most frequently in cerebral contusions, and it is associated with ICP elevations. Male sex, older age, time from injury to first CT scan, and PTT appear to be key determinants of PHI. Early repeated CT scanning is indicated in patients with nonsurgically treated hemorrhage revealed on the first CT scan.
Ruptured aneurysm on a double origin of the posterior inferior cerebellar artery: a pathological entity in an anatomical variation
Authors: Pasco Anne , Thouveny Francine , Papon Xavier , Tanguy Jean-Yves , Mercier Philippe , Caron-Poitreau Christine , Herbreteau Denis 
Published: May 2009

✓ The posterior inferior cerebellar artery (PICA) is known to be very variable, and some of its anatomical variations can explain ischemic complications that occur during endovascular treatment of aneurysms. The authors report two cases of anatomical variation of the PICA that they have called its double origin, one of which gave rise to an aneurysm.
The first patient was a 36-year-old man who presented with a subarachnoid hemorrhage related to the rupture of a PICA aneurysm. The aneurysm was treated by the endovascular route. Selective and superselective studies showed that the PICA origin was low on the fourth segment of the vertebral artery (VA). The aneurysm was located on an anastomosis between the PICA and a small upper arterial branch originating from the VA. Embolization was performed through the small branch with no problem, but a lateral medullary infarct followed, probably due to occlusion of the perforating vessels. The same anatomical variation was incidentally discovered in the second patient.
To the authors' knowledge, neither this anatomical variation of the PICA nor the aneurysm's topography have been previously described angiographically. This highlights the role of angiography in pretreatment evaluation of aneurysms especially when perforating vessels or small accessory branches that are poorly visualized on angiographic studies are concerned, as in the territory of the PICA. Anatomy is sometimes unpredictable, and the surgeon must be very careful when confronted with these variations because they are potentially dangerous for endovascular treatment.
Bypass combined with embolization via a venous graft in a patient with a giant aneurysm in the posterior communicating artery and bilateral idiopathic occlusion of the internal carotid artery in the neck
Authors: Santoro Antonio , Passacantilli Emiliano , Guidetti Giulio , Dazzi Mauro , Guglielmi Guido , Cantore Giampaolo 
Published: May 2009

✓ The authors describe the case of a patient with a symptomatic giant aneurysm of the posterior communicating artery (PCoA) associated with bilateral idiopathic occlusion of the internal carotid artery (ICA). The presence of severe tortuosity of the vertebral arteries (VAs), both at their origin from the subclavian artery and at the level of the third segment, impeded navigation of the catheter for embolization of the aneurysm with Guglielmi detachable coils (GDCs).
A direct surgical approach was considered to be a high-risk procedure because of the bilateral occlusion of the ICAs and the size of the aneurysm. The following therapeutic strategy was therefore adopted: 1) balloon occlusion test of the left VA; 2) vertebro—vertebral bypass with saphenous vein graft to provide a pathway for subsequent embolization; 3) ICA—left middle cerebral artery bypass to ensure blood flow in the event that embolization resulted in closure of the PCoA; and 4) GDC embolization of the aneurysm via the posterior circulation graft to ensure complete exclusion of the lesion from the arterial circulation and preservation of the PCoA. At 3-month follow-up review the patient did not present with any neurological deficits; at 1-year control examination, magnetic resonance (MR) imaging and MR angiography both confirmed complete exclusion of the aneurysm and patency of the two bypasses.
Interactive stereoscopic virtual reality: a new tool for neurosurgical education
Authors: Henn Jeffrey S. , Lemole G. Michael , Ferreira Mauro A. T. , Gonzalez L. Fernando , Schornak Mark , Preul Mark C. , Spetzler Robert F. 
Published: May 2009

✓ The goal of this study was to develop a new method for neurosurgical education based on interactive stereoscopic virtual reality (ISVR). Interactive stereoscopic virtual reality can be used to recreate the three-dimensional (3D) experience of neurosurgical approaches much more realistically than standard educational methods. The demonstration of complex 3D relationships is unrivaled and easily combined with interactive learning and multimedia capabilities.
Interactive stereoscopic virtual reality permits the accurate recreation of neurosurgical approaches through integration of several forms of stereoscopic multimedia (video, interactive anatomy, and computer-rendered animations). The content explored using ISVR is obtained through a combination of approach-based cadaver dissections, live surgical images and videos, and computer-rendered animations. These media are combined through an interactive software interface to demonstrate key aspects of a neurosurgical approach (for example, patient positioning, draping, incision, individual surgical steps, alternative steps, relevant anatomy). The ISVR platform is designed for use on a desktop personal computer with newly developed, inexpensive, platform-independent shutter glasses.
Interactive stereoscopic virtual reality has been used to capture the anatomy and methods of several neurosurgical approaches. In this paper the authors report their experience with ISVR and describe its potential advantages. The success of a neurosurgical approach is contingent on the mastery of complex, 3D anatomy. A new technology for neurosurgical education, ISVR can improve understanding and speed the learning process. It is an effective tool for neurosurgical education, bridging the substantial gap between textbooks and intraoperative training.
Changes in the epithelium of Rathke cleft cyst associated with inflammation
Authors: Hama Seiji , Arita Kazunori , Nishisaka Takashi , Fukuhara Toshiyuki , Tominaga Atsushi , Sugiyama Kazuhiko , Yoshioka Hiroyuki , Eguchi Kuniki , Sumida Masayuki , Heike Yuji , Kurisu Kaoru 
Published: May 2009

Object. Rathke cleft cysts (RCCs) are composed of tall, well-differentiated, ciliated columnar epithelia. Their structures are altered by hyperplasia or squamous metaplasia, but their cause remains unknown.
Methods. The authors studied pathological findings and anterior pituitary function in 20 patients harboring RCCs. They classified RCC epithelium as either single (a single ciliated columnar cell lining or a flattened cuboidal cell lining) or stratified (a stratified ciliated columnar cell lining, basal cell hyperplasia, columnar cell hyperplasia, or squamous metaplasia). Inflammation was classified as acute, subacute, chronic, or end stage.
The epithelial cell lining was observed in 13 specimens obtained during surgery (six specimens contained single and seven contained stratified epithelia). Inflammation had penetrated the cyst epithelium or subjacent stroma in 10 patients, and the stage of inflammation correlated well with the type of epithelia group: early stages of inflammation in the single epithelium group and chronic or end-stage inflammation in the stratified epithelia (p = 0.0027). The adenohypophysis was identified in 21 surgical specimens. Postoperatively, growth hormone (p = 0.019), cortisol (p = 0.027), and thyroid-stimulating hormone (p = 0.039) responses significantly worsened as the inflammation progressed. The presence of diabetes insipidus correlated well with advanced stages of neurohypophysitis (p = 0.025).
Conclusions. Epithelial stratification in the RCC is caused by inflammation that may extend into the adjacent adenohypophysis or neurohypophysis and overwhelm the hypophysis, resulting in panhypopituitarism. Transsphenoidal excision may represent the best choice for treatment, at least for cases of RCC in which there is partial impairment of hypophysial function.
Quality-of-life assessment in patients who had been surgically treated for cerebellar pilocytic astrocytoma in childhood
Authors: Pompili Alfredo , Caperle Marco , Pace Andrea , Ramazzotti Valerio , Raus Laura , Jandolo Bruno , Occhipinti Emanuele 
Published: May 2009

Object. After radical surgery for childhood cerebellar astrocytomas, patients are considered to be cured. Long-term follow up demonstrates that these patients survive, with most of them leading a normal life. The study reported here was aimed at assessing the quality of life (QOL) of these adults, which is defined as a person's sense of well-being, as derived from his or her current experience of life as a whole.
Methods. Twenty patients who had undergone surgery between 1970 and 1985 were enrolled in the study. In four patients ventriculoperitoneal shunts were in place; two of these patients had required more than six shunt revisions. At present, all patients have clear neuroimaging studies and their Karnofsky Performance Scale (KPS) scores are as follows: 70 in three, 80 in seven, 90 in six, and 100 in four. A QOL questionnaire was administered to the patients and to a control group consisting of 20 healthy volunteers of matching age and sex. The chi-square test was applied to compare patients and controls. Traditional questions on the level of education, work, whether the patients have their own families, and whether they possessed a driver's license were asked at the end of the questionnaire.
In all the dimensions assessed except one (sex life), the difference between patients and control volunteers was significant, socializing and adolescence being the most striking ones. This was also true when the three patients with the lowest KPS scores and the worst QOL results were excluded.
Conclusions. By traditional standards, these patients appear to fare quite well. Nevertheless, their self-reported life experience is unsatisfying when compared with the control group. The authors conclude that psychosocial factors are critical to complete recovery and the QOL of children who undergo successful operations for benign cerebellar astrocytoma.
Cerebellar hemorrhage arising prospectively as a complication of supratentorial surgery: a retrospective study
Authors: Honegger Jürgen , Zentner Josef , Spreer Joachim , Carmona Hans , Schulze-Bonhage Andreas 
Published: May 2009

Object. Postoperative cerebellar hemorrhage as a complication of supratentorial surgery is an increasingly recognized clinical entity. So far, it has remained unclear whether this complication constitutes an intraoperative or postoperative event. The observation of such cases prompted the authors to analyze retrospectively their series of supratentorial craniotomies. The aim of this study was to determine the incidence of cerebellar hemorrhage and its temporal relationship to supratentorial surgery.
Methods. The authors reviewed discharge notes and reports on postoperative computerized tomography (CT) scans for 1650 patients who had undergone supratentorial craniotomy between January 1998 and February 2001.
The retrospective study led to the identification of 10 patients who had sustained cerebellar hemorrhage as a complication of supratentorial surgery. Because it was routine to perform CT scanning following craniotomy, an early CT scan obtained within the 1st postoperative hour (mean 24 minutes after wound closure) was available in eight of the 10 patients. In seven of these patients no hemorrhage was found immediately after surgery, and in only one patient was there the suspicion of cerebellar hemorrhage. In the whole series of 10 patients, cerebellar hemorrhage was detected during the later postoperative course, after a mean interval of 7 hours and 35 minutes (range 1 hour and 49 minutes–144 hours) following surgery. The incidence of cerebellar hemorrhage was 0.6% of all patients who underwent supratentorial surgery. Among patients suffering from epilepsy the incidence was 4.6%, and in those patients who underwent temporal lobe resection it was 12.9%.
Conclusions. The authors have demonstrated that cerebellar hemorrhage as a complication of supratentorial surgery arises not as an intraoperative event, but as a postoperative event. Resective nontumorous temporal lobe procedures place patients at particular risk for this complication. Evidence suggests that the complication might be precipitated by postoperative suction drainage.
The impact of neurophysiological intraoperative monitoring on surgical decisions: a critical analysis of 423 cases
Authors: Wiedemayer Helmut , Fauser Barbara , Sandalcioglu Ibrahim Erol , Schäfer Heike , Stolke Dietmar 
Published: May 2009

Object. The aim of this observational clinical study was to analyze the impact of neurophysiological intraoperative monitoring (IOM) on the surgical procedure and to assess the benefits of such monitoring.
Methods. Data for 423 patients who underwent neurophysiological IOM with somatosensory evoked potentials and brainstem auditory evoked potentials during neurosurgical procedures were collected prospectively. The patients were classified into one of five groups according to the findings of IOM, the intervention following a monitoring alarm, and the patient's postoperative neurological condition. These groups were as follows: patients with true-positive findings with intervention (42 cases, 9.9%), those with true-positive findings without intervention (42 cases, 9.9%), those with false-positive findings (nine cases, 2.1%), those with false-negative findings (16 cases, 3.8%), and those with true-negative findings (314 cases, 74.2%). Different interventions followed an event identified with monitoring. These interventions were related to dissection in 17 cases, to perfusion pressure in 11, to a limitation of the surgical procedure in five, to vessel clipping in four, to vasospasm in three, and to retraction in one case. In one case the surgical procedure was abandoned. A critical analysis and cautious estimation of the interventions revealed that IOM was helpful in preventing a postoperative deficit in 5.2% of the monitored cases.
Conclusions. For critical analysis of the benefits of IOM one must evaluate not only the findings of IOM and the patient's postoperative neurological condition but also the intraoperative findings and surgical interventions following a monitoring alarm. Evidence is presented that IOM is helpful in preventing a postoperative deficit.
Brain edema after experimental intracerebral hemorrhage: role of hemoglobin degradation products
Authors: Huang Feng-Ping , Xi Guohua , Keep Richard F. , Hua Ya , Nemoianu Andrei , Hoff Julian T. 
Published: May 2009

Object. The mechanisms involved in brain edema formation following intracerebral hemorrhage (ICH) have not been fully elucidated. The authors have found that red blood cell lysis plays an important role in edema development after ICH. In the present study, they sought to determine whether degradation products of hemoglobin cause brain edema.
Methods. Hemoglobin, hemin, bilirubin, or FeCl2 were infused with stereotactic guidance into the right basal ganglia of Sprague—Dawley rats. The animals were killed 24 hours later to determine brain water and ion contents. Western blot analysis and immunohistochemistry were applied for heme oxygenase-1 (HO-1) measurement. The effects of an HO inhibitor, tin-protoporphyrin (SnPP), and the iron chelator deferoxamine, on hemoglobin-induced brain edema were also examined.
Intracerebral infusion of hemoglobin, hemin, bilirubin, or FeCl2 caused an increase in brain water content at 24 hours. The HO-1 was upregulated after hemoglobin infusion and HO inhibition by SnPP-attenuated hemoglobin-induced edema. Brain edema induced by hemoglobin was also attenuated by the intraperitoneal injection of 500 mg/kg deferoxamine.
Conclusions. Hemoglobin causes brain edema, at least in part, through its degradation products. Limiting hemoglobin degradation coupled with the use of iron chelators may be a novel therapeutic approach to limit brain edema after ICH.