bluuebunny/crossref_metadata_2025 huggingface dataset:
Prey switching and feeding habits of eastern coyotes in relation to snowshoe hare and white-tailed deer densities
Authors: Patterson Brent R , Benjamin Lawrence K , Messier François
Published: April 2011

We investigated the influence of white-tailed deer (Odocoileus virginianus) and snowshoe hare (Lepus americanus) availability on the feeding habits of coyotes (Canis latrans) in Nova Scotia from 1992 to 1997. We hypothesized that coyotes would switch from deer to hare as hare abundance increased. Based on the analysis of 2443 scats, deer and hare were the dominant food items. Other important food items included small mammals, and fruits during late summer. In areas where they were readily available, coyotes fed predominantly on hare during winter, with the use of deer declining as hare density increased. However, the functional response was not proportional to the changes in the relative densities of deer or hare. This was particularly evident at low deer densities, where coyotes continued to feed largely on deer, even in the presence of high hare densities. The consumption of deer fawns during June and July exceeded that of hare in all areas, despite high hare densities in some areas. Overall, high use of deer appeared to have been associated with increased vulnerability due to winter severity or, in the case of young fawns, inability to escape. During mild winters, we suspect that coyotes are forced to focus their hunting efforts on prey other than deer, regardless of density, owing to low vulnerability of deer. When severe winter conditions occur, coyotes switch to feeding mainly on deer.
Thrombin Mutant W215A/E217A Treatment Improves Neurological Outcome and Reduces Cerebral Infarct Size in a Mouse Model of Ischemic Stroke
Authors: Berny-Lang Michelle A. , Hurst Sawan , Tucker Erik I. , Pelc Leslie A. , Wang Ruikang K. , Hurn Patricia D. , Di Cera Enrico , McCarty Owen J.T. , Gruber András
Published: April 2011

Background and Purpose—

Treatment of ischemic stroke by activation of endogenous plasminogen using tissue plasminogen activator is limited by bleeding side effects. In mice, treatment of experimental ischemic stroke with activated protein C improves outcomes; however, activated protein C also has bleeding side effects. In contrast, activation of endogenous protein C using thrombin mutant W215A/E217A (WE) is antithrombotic without hemostasis impairment in primates. Therefore, we investigated the outcome of WE-treated experimental ischemic stroke in mice.

Methods—

The middle cerebral artery was occluded with a filament for 60 minutes to induce ischemic stroke. Vehicle, recombinant WE, or tissue plasminogen activator was administered during middle cerebral artery occlusion or 2 hours after middle cerebral artery occlusion. Neurological performance was scored daily. Intracranial bleeding and cerebral infarct size, defined by 2,3,5-triphenyltetrazolium chloride exclusion, were determined on autopsy. Hemostasis was evaluated using tail bleeding tests.

Results—

WE improved neurological performance scores, increased laser Doppler flowmetry-monitored post-middle cerebral artery occlusion reperfusion of the parietal cortex, and reduced 2,3,5-triphenyltetrazolium chloride-defined cerebral infarct size versus vehicle controls. However, unlike tissue plasminogen activator, WE did not increase tail bleeding or intracranial hemorrhage.

Conclusions—

WE treatment is neuroprotective without hemostasis impairment in experimental acute ischemic stroke in mice and thus may provide an alternative to tissue plasminogen activator for stroke treatment.
Measurement Equivalence of Ordinal Items: A Comparison of Factor Analytic, Item Response Theory, and Latent Class Approaches
Authors: Kankaraš Miloš , Vermunt Jeroen K. , Moors Guy
Published: April 2011

Three distinctive methods of assessing measurement equivalence of ordinal items, namely, confirmatory factor analysis, differential item functioning using item response theory, and latent class factor analysis, make different modeling assumptions and adopt different procedures. Simulation data are used to compare the performance of these three approaches in detecting the sources of measurement inequivalence. For this purpose, the authors simulated Likert-type data using two nonlinear models, one with categorical and one with continuous latent variables. Inequivalence was set up in the slope parameters (loadings) as well as in the item intercept parameters in a form resembling agreement and extreme response styles. Results indicate that the item response theory and latent class factor models can relatively accurately detect and locate inequivalence in the intercept and slope parameters both at the scale and the item levels. Confirmatory factor analysis performs well when inequivalence is located in the slope parameters but wrongfully indicates inequivalence in the slope parameters when inequivalence is located in the intercept parameters. Influences of sample size, number of inequivalent items in a scale, and model fit criteria on the performance of the three methods are also analyzed.
Clinical and Computed Tomography Evaluation of Surgical Outcomes in Tarsal Navicular Stress Fractures
Authors: Mccormick Jeremy J. , Bray Christopher C. , Davis W. Hodges , Cohen Bruce E. , Jones Carroll P. , Anderson Robert B.
Published: April 2011

Background

As clinical suspicion increases and radiographic evaluation improves, navicular stress fractures are becoming a more recognized injury. To date, there is a small volume of literature examining these stress fractures, particularly as it pertains to outcomes of surgical management.

Purpose

To evaluate the clinical and computed tomography (CT) outcomes of surgically treated navicular stress fractures.

Study Design

Case series; Level of evidence, 4.

Methods

Ten navicular stress fractures in 10 patients were available for follow-up at an average of 42.4 months postoperatively (range, 16.8-79.9). These patients underwent a clinical examination and a CT scan of their operatively treated foot. The American Orthopaedic Foot & Ankle Society (AOFAS) and SF-36 scores were completed for each fracture at the time of examination. The CT scans were blindly evaluated for bony union.

Results

According to the CT scan evaluation, 8 of 10 navicula (80%) had gone on to union. Clinical outcome scores on all patients were an average AOFAS hindfoot score of 88.5 and an average SF-36 score of 88.3. The feet with united fractures had an average AOFAS score of 92.1 (range, 83-100) and an average SF-36 score of 91.9 (range, 79-98). The 2 patients with nonunions had AOFAS scores of 74 and 74 and SF-36 scores of 70 and 78, respectively. Both nonunions were complete, displaced fractures on preoperative imaging.

Conclusion

In our series of operatively treated navicular stress fractures, 80% went on to union, as verified by CT scan. Patients with united fractures had a clinically significant improvement in outcome, with higher AOFAS and SF-36 scores as compared with the 2 patients with nonunions. Patients with complete, displaced navicular stress fractures may be more likely to develop nonunions.
Inducing Disbelief in Free Will Alters Brain Correlates of Preconscious Motor Preparation
Authors: Rigoni Davide , Kühn Simone , Sartori Giuseppe , Brass Marcel
Published: April 2011

The feeling of being in control of one’s own actions is a strong subjective experience. However, discoveries in psychology and neuroscience challenge the validity of this experience and suggest that free will is just an illusion. This raises a question: What would happen if people started to disbelieve in free will? Previous research has shown that low control beliefs affect performance and motivation. Recently, it has been shown that undermining free-will beliefs influences social behavior. In the study reported here, we investigated whether undermining beliefs in free will affects brain correlates of voluntary motor preparation. Our results showed that the readiness potential was reduced in individuals induced to disbelieve in free will. This effect was evident more than 1 s before participants consciously decided to move, a finding that suggests that the manipulation influenced intentional actions at preconscious stages. Our findings indicate that abstract belief systems might have a much more fundamental effect than previously thought.
Moving Past “Right” or “Wrong” Toward a Continuum of Young Children’s Semantic Knowledge
Authors: Christ Tanya
Published: April 2011

Vocabulary development is a critical goal for early childhood education. However, it is difficult for researchers and teachers to determine whether this goal is being met, given the limitations of current assessment tools. These tools tend to view word knowledge dichotomously—as right or wrong. A clear sense of children’s depth of semantic knowledge is necessary in order to plan and evaluate the effectiveness of instruction. This article proposes a continuum of young children’s semantic knowledge that stems from a conceptual analysis of literature across the fields of education, linguistics, and educational psychology. Nineteen categories of children’s word knowledge were identified and grouped into five hierarchically related levels: no understanding, schematically related understanding, contextual understanding, decontextual understanding, and paired understanding. This semantic continuum can be used to develop an assessment instrument to measure the incremental changes in young children’s semantic knowledge. Also, it can be used to guide assessment-based vocabulary instruction in early childhood.
Cross-cultural adaptation and validation of Behçet's disease quality of life questionnaire
Authors: Touma Zahi , Ghandour Lilian , Sibai Abla , Puzantian Houry , Hamdan Ayad , Hamdan Omar , Menassa Jeanine , Uthman Imad , Arayssi Thurayya
Published: April 2011

Background

Currently, there is one Behçet's disease (BD) specific self reporting questionnaire developed and published in the literature, The Leeds BD-quality of life (QoL). We conducted a cross-cultural adaptation and validation of the Arabic version of the Leeds BD-QoL

Methods

A cross-sectional study was conducted among 41 consecutive patients attending rheumatology clinics at the American University of Beirut Medical Center between June and December 2007. The BD-QoL questionnaire, the Katz Index of Activities of Daily Living (ADL) and the Lawton Instrumental Activities of Daily Living (IADL) questionnaires were co-administered during the same visit, and severity scores were calculated. Cross-cultural adaptation of BD-QoL was performed using forward and backward translations of the original questionnaire. Internal consistency and test-retest reliability of the final version were determined. Exploratory Factor Analysis (EFA) was used to assess the dimensionality of the scale items. External construct validity was examined by correlating Arabic BD-QoL with the severity score, ADL and IADL.

Results

The 30 items of the adapted Arabic BD-QoL showed a high internal consistency (KR-20 coefficient 0.89) and test-retest reliability (Spearman's test 0.91). The convergence of all 30 items suggests that the 30-item adapted Arabic BD-QoL scale is unidimensional. BD-QoL did not correlate with any of the patients' demographics. Still, it was positively correlated with patient severity score (r 0.4, p 0.02), and IADL (but not ADL).

Conclusions

This cross-cultural adaptation has produced an Arabic BD-QoL questionnaire that is now available for use in clinical settings and in research studies, among Arabic speaking patients.
Astroblastomas: A Pathological Study of 23 Tumors, with a Postoperative Follow-up in 13 Patients
Authors: Bonnin Jose M. , Rubinstein Lucien J.
Published: April 2011

Astroblastomas are rare, usually circumscribed, supratentorial tumors of young subjects and are characterized by a perivascular arrangement of the tumor cells. Their clinical behavior is unpredictable and their prognosis has been regarded as intermediate between that of astrocytomas and glioblastomas. A personal series of 23 astroblastomas was reviewed, adequate postoperative follow-up being available in 13 patients. Two distinct histological types were encountered: low-grade and high-grade. The low-grade type comprised tumors with better differentiated and more benign-appearing microscopical features. Five of the 8 patients with tumors of this type who were available for follow-up have survived from 3 to 20 years after treatment; in I patient the tumor converted into a fatal glioblastoma after 4½12; years. The high-grade type consisted of tumors with more anaplastic features. Three of the 4 patients with tumors of this type available for follow-up died after 1½12; to 2½12; years, the astroblastomas in 2 of them having converted into a glioblastoma and a gliosarcoma, respectively. One patient, however, has had an unexpected length of postoperative survival of 11½12; years. The best clinical results were obtained after total or subtotal resection of the tumor, followed by radiotherapy. The role of chemotherapy is still uncertain. This form of glioma illustrates the discrepancies that may sometimes be apparent between histopathological features and length of postoperative survival. The prognosis is also further complicated by the potential of the astroblastoma to convert into a more malignant type of glioma.
Anterior Cervical Discectomy with Hydroxylapatite Fusion
Authors: Senter Howard J. , Kortyna Rick , Kemp William R.
Published: April 2011

The outcome of microscopic anterior cervical discectomy with iliac crest interbody fusion in a group of 75 patients was compared with that of microscopic anterior cervical discectomy with synthetic hydroxylapatite fusion in a group of 84 patients. The rate of relief of myelopathy (70%) was similar in both groups, but those who underwent synthetic fusion had better long-term relief of radiculopathy, less need for a second operation at the same or an adjacent level, no resorption of the bone plug, comparable spinal alignment and stability, and the elimination of complications at the iliac crest donor site. The data suggest that hydroxylapatite fusion may be equal or superior to autologous iliac crest interbody fusion for anterior cervical disc surgery.
Hemodynamic Assessment of the Spinal Cord Arteriovenous Malformation with Intraoperative Microvascular Doppler Ultrasound: Case Report
Authors: Giller Cole A. , Meyer Yves J. , Batjer Hunt H.
Published: April 2011

Microvascular Doppler recordings were taken from the nidus and draining system of a dural spinal cord arteriovenous malformation during operative treatment. Doppler signals readily showed the direction of blood flow in the draining vein and the hemodynamic effects of surgical maneuvers. Recording during alterations of mean arterial blood pressure and partial carbon dioxide pressure (pCO2) demonstrated lack of autoregulation and impaired CO2 reactivity in the AVM nidus. Microvascular Doppler techniques provide useful intraoperative assessment of the hemodynamics of arteriovenous malformations of the spinal cord.
Tumors of the Choroid Plexus in Children
Authors: Ellenbogen Richard G. , Winston Ken R. , Kupsky William J.
Published: April 2011

Primary neoplasms of the choroid plexus in children are surgically treatable, and the encouraging results of surgical removal, even for carcinoma, justify an aggressive surgical approach, Forty cases operated on over a span of 45 years have been reviewed in detail, including a rereading of all microscopic slides. The prognosis for children with papilloma has been excellent. The 5-year survival rate for children with carcinoma of the choroid plexus was 50%, and all deaths occurred within 7 months of operation. The patients whose carcinomas were totally removed had a better prognosis than did those with subtotal removal.
Magnetic Resonance Imaging of Lipomyelomeningocele and Tethered Cord
Authors: Brophy John D. , Sutton Leslie N. , Zimmerman Robert A. , Bury Edward , Schut Luis
Published: April 2011

The operative and magnetic resonance image (MRI) findings of 25 patients with the diagnosis of lipomyelomeningocele and/or tethered cord were compared. Postoperative MRI scans of eight patients, five of whom were in stable condition, were also compared with the preoperative studies. In this review there was one false negative MRI scan and four MRI scans in which the relationship of the lipoma to the conus or filum was not demonstrated accurately. In six patients, incidental intramedullary cystic lesions at the conus were identified by MRI scan. All eight postoperative (1 month to 2 years) scans demonstrated no change in the level of the conus from the preoperative study. MRI is an accurate screening modality in the initial diagnosis of occult spinal dysraphism. MRI was not useful in the postoperative evaluation of lipomyelomeningocele and the tethered cord, since the caudal, posterior displacement of the conus was unchanged in all studies.
Anatomical Evaluation of the Caudal Regression Syndrome (Lumbosacral Agenesis) with Magnetic Resonance Imaging
Authors: Pappas C. T. E. , Seaver Linda , Carrion Carlos , Rekate Harold
Published: April 2011

Caudal regression syndrome involves absence of the sacrococcygeal vertebrae with or without lumbar vertebral defects. Since the neurological condition of infants with this syndrome deteriorates, radiographic studies are important to rule out any surgically correctable lesion. A paraplegic male neonate with a vertebral canal ending at T11 is presented. This is the first report of using magnetic resonance imaging to evaluate the spinal cord and surrounding soft tissues involved in this syndrome. Magnetic resonance imaging provides more anatomical details than myelogram with computed tomography, which greatly aids in determining whether surgery is necessary.
Cerebral Cavernous Angiomas in the First Year of Life
Authors: Gangemi Michelangelo , Longatti Pieluigi , Maiuri Francesco , Cinalli Giuseppe , Carteri Alessandro
Published: April 2011

Two rare cases of cerebral cavernous angiomas in two infants. 9 and 6 months old, respectively, are reported and the other 11 cases in the literature concerning patients in the first year of life are reviewed. Cavernous angiomas of the brain occur rarely in the first year of life and present with seizures and head enlargement. On computed tomographic scan they typically appear as large, hyperdense, unenhanced masses, with large cysts and must be differentiated from tumors more common in infants, such as teratomas, ependymomas, and mixed tumors. Total removal is often possible, even with large lesions, because of the small amount of bleeding and the well-defined limits of the mass.
Steroid Hormone Receptors in Meningiomas of Chinese Patients
Authors: Lee Liang-Shong , Chi Chin-Wen , Chang Tai-Jay , Chou Min-Deh , Liu Hsiu-Chih , Liu Tsung-Yun
Published: April 2011

Meningioma is a hormone-related intracranial tumor. Brain tumor samples were collected from 32 Chinese patients, 20 of whom had meningiomas. Estrogen receptors were present in 6 of 17 meningiomas, 1 hemangioblastoma, 1 gemistocytic astrocytoma, and 1 neurilemoma. Of the 26 samples assayed for progesterone receptors, measurable bindings were found in 14 of 17 meningiomas, 1 of 2 astrocytomas, 1 malignant lymphoma, 1 hemangioblastoma, 1 ganglioglioma, 1 glioblastoma multiforme, 1 anaplastic ependymoma, 1 small cell sarcoma, and 1 neurilemoma. Androgen receptors were found in 8 of 19 meningiomas, but not in the 11 other brain tumors examined. Measurable glucocorticoid receptors were found in 15 of 19 meningiomas, 1 malignant lymphoma, 1 hemangioblastoma, 2 craniopharyngiomas, 1 neurilemoma, 1 of 2 glioblastomas, and 1 of 2 astrocytomas. Of the 10 samples examined for tyrosine aminotransferase activity, measurable enzyme activity was found in 7 of the 8 meningiomas, but not in the single hemangioblastoma nor in the single craniopharyngioma. In accordance with other published studies, the results from this study also suggest that the growth of meningiomas may be regulated by hormones, and that the role steroid hormones and their receptors play in the meningioma is worthy of further investigation.
Intracranial Meningioma Subsequent to Radiation for a Pituitary Tumor: Case Report
Authors: Sridhar K. , Ramamurthi B.
Published: April 2011

The authors report a case of an intracranial meningioma that developed 33 years after radiation therapy for a pituitary tumor. Radiation-induced tumors form a distinct biological group with aggressive growth characteristics and a malignant potential.
Discitis Caused by the Centers for Disease Control Microorganism Group Ve-1
Authors: Levy David I. , Bucci Michael N. , Hoff Julian T.
Published: April 2011

An unusual case of discitis in a 60-year-old, insulin-dependent, diabetic man is presented. Radiographs of the lumbar spine demonstrated changes associated with infection of the intervertebral disc space. Cultures from the L5-S1 disc space grew the microorganism designated by the Centers for Disease Control as Group Ve-1, an organism that has had questionable clinical significance in the past, and has not been reported as a pathogen in an intervertebral disc space.
Intracranial Cavernous Angioma in the Dura
Authors: Isla Alberto , Roda José M. , Alvarez Fernando , Muñoz Jesús , García Eugenia , Blázquez Martín G.
Published: April 2011

Cavernous malformations located in the dura are rare. We present a case of a large cavernous malformation located in the anterior fossa and implanted in the dura of a pregnant woman. It showed great vascularization on an angiogram, and resembled a meningioma on computed tomographic scan. The operation was difficult because of the tumor's great vascularity and profuse bleeding.
Recovery of Gonadal Function After Resection of an Oligodendroglioma Localized in the Anterior Horn of the Lateral Ventricle: Relation to Pulsatile Secretion of Luteinizing Hormone
Authors: Saitoh Youichi , Arita Norio , Hayakawa Toru , Nakao Kazutami , Mogami Heitaro
Published: April 2011

A 21-year-old man with an oligodendroglioma in the anterior horn of the right lateral ventricle complained of sexual dysfunction and showed lowered concentrations of serum testosterone (1.1 ng/ml) with normal pituitary function. Human chorionic gonadotropin testing revealed a good testosterone response (1.1 to 4.9 ng/ml) and a clomiphene test revealed no gonadotropin response. Pulsatile secretion of luteinizing hormone (LH) was absent preoperatively. After removal of the tumor, serum concentration of testosterone increased to the normal range, LH pulsatility appeared, and the patient had no complaints of sexual dysfunction. In this patient, the loss of LH pulsatility responsible for his hypogonadism was caused by the lateral ventricle tumor compressing the surrounding structures, and this was corrected by tumor resection.
Schwannoma Associated with Anomalous Division of the Median Nerve: Case Report
Authors: Mintz Abraham , Carneiro Ronaldo
Published: April 2011

The authors present a case of a schwannoma associated with high division of the median nerve in a patient who had previously had a diagnosis of a ganglion. The case is presented and the literature concerning these 2 conditions is reviewed.
Mobile Schwannoma of the Cauda Equina Diagnosed by Magnetic Resonance Imaging
Authors: Isu Toyohiko , Iwasaki Yoshinobu , Akino Minoru , Nagashima Masafumi , Abe Hiroshi
Published: April 2011

Three cases of a mobile cauda equina schwannoma, preoperatively diagnosed by magnetic resonance imaging, are described. When dealing with tumors of the cauda equina, it is important to carry out a second magnetic resonance imaging scan after changes in posture, bearing in mind the possibility of mobility of the tumor.
Arterio-inferior Sagittal Sinus Fistulae: Case Report
Authors: Morgan Michael K. , Sundt Thoralf M. , Houser Wayne O.
Published: April 2011

The management of the case of a 9-year-old boy with progressive cognitive impairment due to arteriovenous fistulae at the apex of the inferior sagittal sinus is reported. This represents a unique location for an extraparenchymal deep central arteriovenous malformation. The patient underwent staged ablation of the lesion by surgery. The postoperative course was complicated by expansion of an aneurysmal vein of Galen undergoing thrombosis and hyperperfusion syndrome, but the patient ultimately made a satisfactory recovery.
The Effect of Pin Location on the Rigidity of the Halo Pin-Bone Interface
Authors: Ballock Tracy R. , Lee Thay Q. , Triggs Kevin J. , Woo Savio L.-Y. , Garfin Steven R.
Published: April 2011

Optimal insertion of halo fixation pins to maximize the rigidity of the interface between the halo pins and the outer table of the skull is important in reducing the incidence of pin loosening. An in vitro biomechanical study was performed using cadaver skulls to investigate the effects of pin location on the rigidity of this pin-bone interface. Halo pins were inserted at nine positions within a recommended “safe zone” for pin insertion. It was found that the rigidity of the pinbone interface progressively decreased as pins were inserted more superiorly on the calvaria. The rigidity of the interface did not change significantly when the location of the pins was varied in the horizontal axis. This reduction in interface rigidity associated with inserting pins more superiorly on the skull may be related to an increase in the angle of insertion of the pins with respect to the surface of the calvaria. Based on this study, a change in the technique of halo pin insertion is recommended. Pins should be placed as inferiorly as possible, close to the supraorbital ridge, to achieve the most perpendicular angle of insertion and thus the most rigid fixation. The improved rigidity obtained with perpendicular pin insertion may minimize the rate of pin loosening and other complications associated with use of the halo orthosis. (Neurosurgery 26:238-241. 1990)
Pituitary Adenomas that Produce Adrenocorticotropic Hormone and A-Subunit: Clinicopathological, Immunohistochemical, Ultrastructural, and Immunoelectron Microscopic Studies in Nine Cases
Authors: Berg Kathryn K. , Scheithauer Bernd W. , Felix Ignacio , Kovacs Kalman , Horvath Eva , Klee George G. , Laws Edward R.
Published: April 2011

Eight surgical and one autopsy specimen of pituitary adenomas (six cases of Cushing's disease, two of Nelson's syndrome. and one of hypopituitarism) were studied by histochemical, immunohistocytological, and ultrastructural methods. Eight tumors showed the characteristic histochemical profile of corticotroph adenoma—amphophilic to basophilic, and periodic acid-Schiff-positive to some extent. In all tumors, immunohistochemical studies revealed adrenocorticotropic hormone (ACTH) and à-subunit in the cytoplasm of some adenoma cells. By electron microscopy, seven tumors were found to be monomorphous; six were typical corticotroph adenomas and one was a subtype II silent corticotroph adenoma. One unique lesion was bimorphous—i.e., composed of corticotrophs as well as cells resembling glycoprotein cells. Immunoelectron microscopy by the double-labeling immunogold technique, performed on one corticotroph adenoma, demonstrated the presence of ACTH and à-subunit not only within the same adenoma cells but also within the same secretory granules. The cytogenesis of ACTH à-subunit tumors, a rare form of plurihormonal adenoma. remains to be elucidated. The duration of disease associated with these tumors exceeded the duration in patients with ordinary corticotroph adenomas. Given the low frequency with which increases in serum à-subunit are detectable in patients with such tumors—13% in this series—hormone production is not recognized at preoperative evaluation.
Small Bowel Obstruction Secondary to Incomplete Removal of a Ventriculoperitoneal Shunt
Authors: Hlavin Mary Louise , Mapstone Timothy B. , Gauderer Michael W.L.
Published: April 2011

Small bowel obstruction and partial enteral loss secondary to entrapment by an incompletely removed ventriculoperitoneal shunt is a previously unreported hazard.
Multiple Peripheral Aneurysms of the Posterior Inferior Cerebellar Artery Associated with a Cerebellar Arteriovenous Malformation
Authors: Mintz Arlan , Cosgrove Rees G.
Published: April 2011

The authors describe a rare case of multiple peripheral aneurysms of the posterior inferior cerebellar artery found in association with a midline cerebellar arteriovenous malformation. Successful trapping of the aneurysms and excision of the arteriovenous malformation was accomplished with an excellent clinical result. The literature concerning aneurysms of the posterior inferior cerebellar artery, cerebellar arteriovenous malformations, and combined intracranial vascular abnormalities is discussed.
An Unusual Type of Hangman's Fracture
Authors: Marotta T. R. , White L. , TerBrugge K. G. , Spiegel S. M. , Stevens J. K. , Tator C. M.
Published: April 2011

An unusual fracture of the axis was best displayed using three-dimensional reconstruction. The fracture was noted to differ significantly from the usual “hangman's fracture” as it involved the body of C2 with subluxation of the anterior part of C2 forward on C3 and without “decompression” of the spinal canal at the C2 level. Better understanding made feasible by three-dimensional reconstruction had important treatment implications in this case.
Spinal Cord Cavernous Malformation in a Patient with Familial Intracranial Cavernous Malformations
Authors: Lee Stuart K. , Spetzler Robert F.
Published: April 2011

The case of a 30-year-old woman with a hemorrhage caused by a rare intramedullary cavernous malformation is presented. The patient underwent laminectomy with total removal of the lesion. A cranial magnetic resonance imaging scan demonstrated multiple cavernous malformations. The patient's asymptomatic sister also had multiple intracranial cavernous malformations, one of which was associated with a venous malformation.
Positron Emission Tomographic Studies on Cerebral Hemodynamics in Patients with Cerebral Contusion
Authors: Tenjin Hiroshi , Ueda Satoshi , Mizukawa Norihiko , Imahori Yoshio , Hino Akihiko , Yamaki Tarumi , Kuboyama Tetsuhiko , Ebisu Toshihiko , Hirakawa Kimiyoshi , Yamashita Masato , Nakahashi Hisamitsu
Published: April 2011

Positron emission tomography is currently one of the most useful methods for measurements of cerebral hemodynamics and oxygen metabolism, because it facilitates accurate analysis of the local cerebral circulation in three-dimensional quantitative images. In this study, we performed positron emission tomography studies to measure cerebral circulation in a total of 11 patients who sustained head injuries with contusion. Several parameters were measured including regional cerebral blood flow, regional cerebral blood volume, permeability, and regional cerebral metabolic rate for oxygen. Data from brains both with and without contusion were analyzed for chronological changes, in the subacute stage from the 8th to 29th day and in the chronic stage until 360 days after the injury and compared with similar data in a group of normal subjects. It was concluded that in the subacute stage, regional cerebral blood flow decreased (26 ± 7 and 39 ± 10 ml/100 g/min) and regional cerebral blood volume increased (5.6 ± 1.8 and 5.4 ± 0.9 ml/100 g) both in areas of cerebral contusion and in areas remote from cerebral contusion and that permeability increased in areas of contusion but not in remote brain areas. In the chronic stage, these parameters showed a tendency for recovery.
Clinical versus Subclinical Pituitary Apoplexy: Presentation, Surgical Management, and Outcome in 21 Patients
Authors: Onesti Stephen T. , Wisniewski Thomas , Post Kalmon D.
Published: April 2011

A retrospective review of 16 consecutive patients with pituitary apoplexy treated over a 10-year period is reported. Eight men and 8 women (mean age, 48 years) underwent transsphenoidal decompression after an average duration of symptoms of 19 days. The diagnosis of pituitary apoplexy was made by the sudden onset of headache (88%), nausea (56%), or meningismus (13%), with or without visual disturbances (75%), in the setting of a sellar tumor on computed tomographic or magnetic resonance imaging scans. Thirteen of 16 patients showed significant improvement of symptoms after surgery (average follow-up, 2.5 years). In addition, 5 patients with clinically silent yet extensive pituitary hemorrhage were treated. Although extensive pituitary hemorrhage often produced fulminant apoplexy, it also presented insidiously over many days with few, if any, clinical signs. Rapid diagnosis, endocrine replacement, and transsphenoidal decompression constituted effective therapy. Magnetic resonance imaging (after at least 12 hours of symptoms) was superior to computed tomography in detecting hemorrhage.
Calcified Metastatic Brain Tumor
Authors: Tashiro Yuzuru , Kondo Akinori , Aoyama Ikuhiro , Nin Kiyoshi , Shimotake Katsumi , Tashiro Haruhiko , Nishioka Tatsuya
Published: April 2011

The case of a 57-year-old woman with a calcified metastatic brain tumor. histologically confirmed to be a squamous cell carcinoma, is reported. This patient is unusual because this metastatic squamous cell carcinoma contained an extraordinary huge conglomerated calcification, that was well-defined radiographically. This case is documented with a discussion of the pathogenesis of the calcification.
Multiparameter Flow Cytometric Analysis of Neoplasms of the Central Nervous System: Correlation of Nuclear Antigen p105 and DNA Content with Clinical Behavior
Authors: Appley Alan J. , Fitzgibbons Patrick L. , Chandrasoma Parakrama T. , Hinton David R. , Apuzzo Michael L. J.
Published: April 2011

Analysis of the DNA content of various solid tumors and hematological malignancies may provide useful prognostic information. To date, however, there has been a striking lack of correlation between DNA content in neoplasms of the central nervous system and clinical behavior. Simultaneous quantitation of DNA content and proliferation-associated nuclear antigen (p105) by flow cytometry was performed on paraffin-embedded tissues representing three major groups of central nervous system neoplasms—1) 21 astrocytic tumors, 2) 13 pituitary tumors, and 3) 19 meningiomas-and the results were correlated with clinical behavior. All 4 well-differentiated gliomas were diploid, while 3 of 9 anaplastic astrocytomas and 1 of 8 glioblastomas had a demonstrable aneuploid peak. Three of 13 pituitary tumors had an identifiable aneuploid peak, while only 2 of 19 meningiomas had an aneuploid DNA content. Cell-cycle analysis of the malignant gliomas revealed a significantly higher proliferative index (PI, %S + G2M) compared with the well-differentiated astrocytomas (P< 0.05). Within the subgroup of diploid anaplastic astrocytomas, however, extended patient survival appeared to be associated with a higher PI. For diploid pituitary adenomas, the PI was consistently lower in the 3 tumors that recurred than it was in the remaining 8 adenomas. Nuclear antigen quantitation of diploid tumors showed a wide range of p105 expression in G0G1cells, suggesting that, within each tumor, the cells are heterogeneous with respect to proliferative activity. Aneuploid nuclei of glial tumors showed enhanced expression of p105 relative to diploid cells of the same specimen. In pituitary tumors, the median G2M/G0G1fluorescence ratio for p105 was significantly higher (P< 0.05) for the 3 diploid recurrent tumors than for those that did not recur. These data support the assumption that the aggressive clinical course of malignant glial neoplasms may be related to an abnormal DNA stemline and/or an alteration in cell proliferative activity. Cell cycle analysis and measurement of p105 by this technique may provide information useful from both a prognostic standpoint and in directing adjuvant therapy.
Temporary Balloon Occlusion of a Proximal Vessel as an Aid to Clipping Aneurysms of the Basilar and Paraclinoid Internal Carotid Arteries: Technical note
Authors: Shucart William A. , Kwan Eddie S. , Heilman Carl B.
Published: April 2011

One aneurysm of the basilar artery and three large, paraclinoid aneurysms of the internal carotid artery (ICA) were treated with the aid of intraoperative temporary balloon occlusion of the vessel. Optimal clip placement was confirmed using intraoperative angiography. This technique provided excellent proximal vascular control and for the large aneurysms of the paraclinoid ICA obviated the need for surgical exposure of the ICA in the neck. We think this is a useful adjunct in the surgical management of aneurysms of both the basilar artery and proximal ICA.
Treatment of Malignant Gliomas with Surgery, Intra-arterial Infusions of 1-(2-Hydroxyethyl)chloroethylnitrosourea, and Radiation Therapy: A Phase II Study
Authors: Fauchon François , Davila Luis , Chatellier Gilles , Fohanno Denis , Philippon Jacques , Rey Alain , Chiras Jacques , Poisson Michel , Delattre Jean Yves , Delattre Jean Yves
Published: April 2011

Forty patients with malignant supratentorial gliomas were treated with surgery, intra-arterial infusions of 1-(2-hydroxyethyl) chloroethylnitrosourea, and radiation therapy. The median duration of survival was 12 months: it differed according to the histological subtype (over 30 months for patients with anaplastic astrocytomas or anaplastic oligoden-droglioma and 10.5 months for glioblastoma; P= 0.0025). Serious complications of monocular blindness and leukoencephalopathy were observed in four patients (10%).
Phosphorus-31 Magnetic Resonance Spectroscopy of Cerebral Ischemia in Cats
Authors: Kobayashi Hidenori , Hayashi Minoru , Kawano Hirokazu , Handa Yuji , Kabuto Masanori , Ide Hisashi
Published: April 2011

The energy metabolism of the brain was measured in three types of ischemic models in the cat using phosphorus-31 magnetic resonance spectroscopy. The cerebral ischemia was produced as follows. In Group 1, two balloons were inflated in the left subclavian artery and the brachiocephalic trunk. In Group 2, the left middle cerebral artery was occluded through a transorbital approach. A combination of the two was employed in Group 3. Phosphorus-31 magnetic resonance spectra were obtained serially during 2 hours of ischemia. Immediately after occlusion, peaks of phospho-creatine and adenosine triphosphate decreased, whereas the peak of inorganic phosphate increased and split in two. Intracellular pH determined by chemical shift of the inorganic phosphate peak decreased. These changes were more pronounced in Group 3 when compared with the other groups. Histological study showed no infarction in Group 1 and infarcted areas in Groups 2 and 3. The size of the infarcted area in Group 3 was larger than that in Group 2. These results suggest that the model of middle cerebral artery occlusion potentiated with the occlusion of the brachiocephalic trunk and the left subclavian artery by balloon catheters is a reliable stroke model and that phosphorus-31 magnetic resonance spectroscopy is useful to understand the pathophysiological state of cerebral ischemia in vivo.
The Effect of Arteriovenous Malformation Resection on Cerebrovascular Reactivity to Carbon Dioxide
Authors: Young William L. , Prohovnik Isak , Prohovnik Isak , Prohovnik Isak , Ornstein Eugene , Ostapkovich Noeleen , Sisti Michael B. , Solomon Robert A. , Stein Bennett M.
Published: April 2011

To investigate the cerebral hemodynamic changes associated with obliteration of arteriovenous malformations (AVMs), we studied 26 patients undergoing total microsurgical AVM resection during isoflurane and N2/O2anesthesia. Detectors were placed 5 to 6 cm from the margin of the lesion and in a homologous contralateral position. Cerebral blood flow (CBF) was measured using the intravenous xenon-133 technique before and after AVM resection, during both hypocapnia and normocapnia at each stage. Intraoperative changes in CBF were related to a risk score system based on the patient's history and preoperative angiograms. Seven otherwise healthy patients undergoing spinal surgery were studied to control for anesthetic effects. Patient demographic and clinical data for the AVM group conformed to the expected strata of a large AVM population. The CBF increased after excision (22 ± 1 ml/100 g/min before excision to 30 ± 2 ml/100 g/min after excision; mean ± SE. n = 25, P < 0.002) without a hemispheric difference. CO2reactivity increased slightly after excision (4.2 ± 0.3% change/mm Hg before excision to 4.7 ± 0.3% change/mm Hg after excision; n = 14, P < 0.02). The baseline CBF and CO2reactivity were not different from the control group. There was a weak correlation between the risk score and the percentage of change in the ipsilateral CBF, with a trend for the patients with the lowest risk to have the lowest CBF changes after resection. There was no relationship between CO2reactivity and risk grade. None of the patients awoke from anesthesia with unexpected neurological deficits. The highest CBF increases were associated with postoperative brain swelling in one patient and fatal intracerebral hemorrhage in another. Both patients had normal CO2reactivity before excision. One patient suffered postoperative intracerebral hemorrhage, attributable to technical problems, and had no increase in CBF. We conclude that, with an acute increase in the arteriovenous pressure gradient (and cerebral perfusion pressure) that results from shunt obliteration, there is an immediate global effect of AVM resection to increase CBF. Cerebrovascular reactivity to CO2remains intact both before and after excision.
Pituitary Adenoma and Parasellar Cysts
Authors: Spaziante Renato , Irace Claudio , de Divitiis Enrico
Published: April 2011

Two cases of pituitary adenoma associated with a parasellar cyst are reported; only one similar case has been described previously. Even though such an association may be coincidental, a pathogenetic relationship between the two lesions in one of our cases may be assumed: shrinkage of the prolactin-secreting pituitary adenoma by means of bromocriptine therapy did, in fact, cause collapse of the cyst. Such an occurrence must not be disregarded in considering the therapeutic approach.
Infiltrating Spinal Angiolipoma Causing Myelopathy: Case Report
Authors: Kuroda Satoshi , Abe Hiroshi , Akino Minoru , Iwasaki Yoshinobu , Nagashima Kazuo
Published: April 2011

We present a case of an infiltrating spinal angiolipoma demonstrating extension into the vertebral body and the spinal epidural space. The infiltration into the epidural space caused myelopathy. About 40 cases of spinal angiolipoma and angiomyolipoma have been reported; however, only a few cases have been the infiltrating type. The radiological findings were similar to those of vertebral hemangioma, but poor enhancement of the angiolipoma on contrast-enhanced computed tomographic scans differentiated between them. The infiltrating epidural tumor was removed, and the clinical symptoms improved remarkably. Total removal of the tumor and stabilization of the involved vertebral body using the anterolateral approach may be desirable when a diagnosis of angiolipoma or angiomyolipoma is confirmed preoperatively.
Intrathoracic Meningocele Associated with Neurofibromatosis: Case Report
Authors: Dolynchuk Kenneth N. , Teskey John , West Michael
Published: April 2011

The authors present a case of intrathoracic meningocele associated with neurofibromatosis. Computed tomography with metrizamide myelography proved valuable in locating the lesion, thus facilitating surgical intervention. With the preoperative diagnosis established and the severity of the meningocele known, the surgeons safely employed a subpleural approach at thoracotomy.
Limited Selective Posterior Rhizotomy for the Treatment of Spasticity Secondary to Infantile Cerebral Palsy: A Preliminary Report
Authors: Lazareff Jorge A. , Mata-Acosta Ana Maria , Garcia-Mendez Martha Alejandra
Published: April 2011

A limited selective posterior rhizotomy was performed on 30 children suffering from spasticity secondary to infantile cerebral palsy. As opposed to standard techniques that stimulate and divide the dorsal rootlets from L2 to S1, we dissected L4, L5, and S1 dorsal roots through an L5 to S1 laminectomy. Eight to 12 rootlets from each root were electrically stimulated with two unipolar electrodes (pulse width, 50 µsec: 10–50 V). The muscle responses were observed visually and registered by electromyography. Those rootlets associated with an abnormal motor response as evidenced by sustained muscular contraction or by prolonged electromyographic response were divided. Spasticity was scored from 0 to ++++. The muscular groups assessed were those involved in the flexion of the shoulder, elbow and wrist in the upper limbs, and those involved in flexion and adduction of the hip, flexion of the leg, and plantar flexion in the lower limbs. The patients were assessed 1 week before and 6 months after the operation. Reduction of spasticity was observed in all the muscular groups, and all the patients presented functional improvement of motor abilities. These preliminary results indicate that a limited procedure that reduces the extension of the laminectomy and the length of the operation could be effective for treating spasticity secondary to infantile cerebral palsy.
Paraplegia after a Routine Lumbar Laminectomy: Report of a Rare Complication and Successful Management
Authors: Valls Patrick L. , Naul Gill L. , Kanter Steven L.
Published: April 2011

Arachnoid cysts of the spinal canal are relatively common lesions that may be either intra- or extradural. These cysts are usually asymptomatic but may produce symptoms by compressing the spinal cord or nerve roots. We report a case in which an intradural thoracic arachnoid cyst became symptomatic after a routine decompressive lumbar laminectomy for spinal stenosis. Myelography revealed no abnormality, although magnetic resonance imaging and computed tomography after myelography demonstrated a mass within the posterior aspect of the thoracic spinal canal associated with anterior displacement and compression of the spinal cord. A change in the flow dynamics of the cerebrospinal fluid probably allowed the development of spinal cord compression due to one of the following: expansion of the cyst, decreased cerebrospinal fluid buffer between the cord and the cyst, or epidural venous engorgement. A concomitant and more cephalad lesion such as an arachnoid cyst should be considered when myelopathic complications arise after lumbar surgery. Magnetic resonance imaging and computed tomography after myelography are useful to demonstrate the additional pathological processes.
Suprasellar Pituitary Adenoma Arising from the Pars Tuberalis: Case Report
Authors: Hamada Junichirou , Seto Hiroshi , Miura Masaki , Kuratsu Junichi
Published: April 2011

A rare case of suprasellar pituitary adenoma arising from the pars tuberalis in a 53-year-old woman is presented. The tumor was located exclusively above the diaphragma sellae, and no invasion into the sella turcica was noted.
Angiographic Study of Induced Cerebral Aneurysms in Primates
Authors: Kim Choegon , Kikuchi Haruhiko , Hashimoto Nobuo , Hazama Fumitada
Published: April 2011

Five cynomolgus monkeys treated with unilateral carotid ligation, renal hypertension, and β-aminopropionitrile feeding were studied repeatedly by cerebral angiography to clarify the growth process of saccular cerebral aneurysms. Repeated angiography demonstrated saccular cerebral aneurysms in three of five monkeys; two aneurysms were found 15 months and a third 12 months after the operation. At autopsy, one saccular aneurysm was found to be bilocular in shape, and the others were unilocular. Fusiform aneurysms were also observed in four monkeys. Microscopic studies revealed the walls of the saccular aneurysms were very thin and consisted of fibrous tissue. In one aneurysm, the aneurysmal sac was almost obstructed by a well-organized thrombus. No evidence of intramural hemorrhage was found in any of the saccular cerebral aneurysms. The conversion of early aneurysmal changes into saccular aneurysms was found in any of the abruptly, and no consistent growth rate was noted. The multiloculation of saccular aneurysms was closely related to the size of an aneurysm. The present study indicates that a saccular cerebral aneurysm may grow abruptly from one of several different kinds of early aneurysmal changes.