bluuebunny/crossref_metadata_2025 huggingface dataset:
Vascularization and microvascular permeability in solid versus cell-suspension embryonic neural grafts
Authors: Leigh Kerrie , Elisevich Kost , Rogers Kem A.
Published: May 2009

✓ Vascularization and microvascular permeability were assessed in a comparative study of solid (organized) and cell-suspension (dissociated) fetal nigral grafts implanted in the dopamine-deprived striatum of adult rats. Both graft types were analyzed by chromogen detection of intravenously injected horseradish peroxidase (HRP), which outlined vessel walls, and, in cases in which the blood-brain barrier was compromised, permeated the graft and host parenchyma. Survival of graft-derived dopaminergic cells was assessed using tyrosine hydroxylase (TH) immunocytochemistry. Glial reactivity to cell-suspension grafts was similarly assessed with an antibody directed against glial fibrillary acidic protein. Morphometry revealed significantly higher microvessel density in the cell-suspension grafts (p < 0.001), which effectively equaled that found in the contralateral striatum despite rather prominent surrounding glial reactivity. Capillaries in the cell-suspension grafts were not permeable to blood-borne HRP at postimplantation study times of 7, 14, and 30 days whereas, in the solid grafts, permeability in some cases could be detected for up to 30 days. Large numbers of cells immunoreactive for TH were seen in cell-suspension grafts; in contrast, few if any were found in the majority of solid transplants.

The multiple-fragment solid graft implant model used clinically compares poorly with the cell-suspension model because it lacks consistency in early revascularization and shows a greater (albeit temporary) tendency for blood-brain barrier dysfunction. Delayed and inadequate vascularization of the solid graft is likely to account for graft failure more often than in the cell-suspension graft. Similarly, a certain critical number of specific grafted cells are required to achieve sufficient expression to bring about a favorable response in the disabled host, and this expression appears to be achieved less consistently with the solid implant technique.
Necrosis in a meningioma following systemic chemotherapy
Authors: Bernstein Mark , Villamil Alfonso , Davidson George , Erlichman Charles
Published: May 2009

✓ Radiological and clinical evidence of acute necrosis in a meningioma following one cycle of chemotherapy with 5-fluorouracil, folinic acid, and levamisole was observed in a patient being treated for invasive rectal carcinoma. The possible mechanisms and implications of this occurrence are discussed.
Hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber disease) presenting with polymicrobial brain abscess
Authors: Hall Walter A.
Published: May 2009

✓ A 26-year-old man presented with expressive aphasia, weakness of the right arm, and anemia but there was no family history of hereditary hemorrhagic telangiectasia. Computerized tomography (CT) of the head demonstrated an enhancing left frontal mass, which was aspirated and on culture yielded multiple organisms. Pulmonary arteriovenous fistulae identified in both lungs by chest radiography, CT, and angiography were treated with coil embolization. Treatment of pulmonary arteriovenous fistulae and prolonged surveillance are necessary to prevent future neurological complications.
Giant posterior communicating artery aneurysm presenting as third ventricle mass with obstructive hydrocephalus
Authors: Smith Kris A. , Kraus Gary E. , Johnson Blake A. , Spetzler Robert F.
Published: May 2009

✓ The case of a giant posterior communicating artery (PCoA) aneurysm is reported in which the initial presentation was coma secondary to obstructive hydrocephalus. The primary radiological diagnosis was a probable craniopharyngioma. A cerebral angiogram revealed a partially thrombosed giant PCoA aneurysm on the right side. The patient underwent pterional craniotomy with aneurysm clipping and thrombectomy to relieve mass effect, and has made a good recovery. Review of the literature documents that giant PCoA aneurysms are rare. This is believed to be the first reported case of a PCoA aneurysm presenting as a third ventricle mass with obstructive hydrocephalus. The magnetic resonance imaging characteristics of those third ventricle masses that mandate vascular workup are discussed.
Combined surgical and endovascular treatment of a giant vertebral artery aneurysm in a child
Authors: Khayata Mazen H. , Spetzler Robert F. , Mooy Jan J. A. , Herman James M. , Rekate Harold L.
Published: May 2009

✓ The case is presented of a 5-year-old child who suffered a subarachnoid hemorrhage from a giant left vertebral artery-posterior inferior cerebellar artery (PICA) aneurysm. Initial treatment consisted of surgical occlusion of the parent vertebral artery combined with a PICA-to-PICA bypass. Because of persistent filling of the aneurysm, the left PICA was occluded at its takeoff from the aneurysm. Endovascular coil occlusion of the aneurysm and the distal left vertebral artery enabled complete elimination of the aneurysm. Follow-up magnetic resonance imaging and arteriography performed 6 months postoperatively showed persistent occlusion and elimination of the mass effect. Combined surgical bypass and endovascular occlusion of the parent artery may be a useful adjunct in the management of these aneurysms.
Endoscopic treatment of an oral cephalocele
Authors: Raftopoulos Christian , David Philippe , Allard Serge , Ickx Brigitte , Balériaux Danielle
Published: May 2009

✓ This report describes an unusual cephalocele originating in the temporobasal region and protruding through the sphenopetral area into the oral cavity. A rapid and nonaggressive endoscopic procedure was performed. The relationship between this type of cephalocele, spontaneous anteroinferior temporal encephaloceles, and nasopharyngeal brain heterotopia is discussed.
Stereotactically guided transfrontal removal of intraventricular midline tumors in children
Authors: Giorgi Cesare , Riva Daria
Published: May 2009

✓ Five children with supratentorial intraventricular midline cerebral tumors were operated on using a stereotactically guided transfrontal approach. Assisted by a three-dimensional graphic reconstruction of cerebral anatomy, the surgeon was able to reach and remove the lesion with minimal damage to healthy parenchyma. Neurosurgical and neuropsychological evaluation of the results suggests that this surgical approach is a valid alternative to the transcallosal route. This image-based intraoperative guidance is as effective as landmark-oriented surgery, which requires section of the corpus callosum, possibly leading to neuropsychological deficits, particularly in the pediatric age group.
Platelet-derived growth factor expression and stimulation in human meningiomas
Authors: Black Peter McL. , Carroll Rona , Glowacka Danuta , Riley Kathleen , Dashner Kathleen
Published: May 2009

✓ The platelet-derived growth factor (PDGF) family consists of subunits A and B and receptors α and β. This paper evaluates the potential role of the homodimer PDGF-BB as a growth factor in meningiomas. It analyzes the expression of messenger RNA in members of the PDGF family in these tumors, measures the growth response of meningiomas to exogenous PDGF-BB in culture, and examines the induction of the c-fos proto-oncogene by PDGF-BB. Northern blot analysis was carried out on tissue from 20 meningiomas to measure the expression of PDGF-A, PDGF-B, PDGF-α receptor (PDGF-α-R) and PDGF-β receptor (PDGF-β-R). All tumors expressed PDGF-A and PDGF-B subunits. Nineteen of the 20 tumors expressed PDGF-β-R and none expressed PDGF-α-R as measured by this technique.

Because the β receptor is selectively sensitive to stimulation by the PDGF-B subunit, these data suggest that meningiomas might be susceptible to stimulation by PDGF-BB. To test this hypothesis, the effect of exogenous PDGF-BB on meningioma growth was evaluated by incubating cells from 10 human meningiomas. Tritiated thymidine incorporation was used to evaluate stimulation of growth over a 48-hour period using PDGF-BB concentrations of 1, 3, or 6 ng/ml. Linear regression analysis and multiple-factor analysis of variance were used to measure PDGF-BB effects. Three of the 10 tumor specimens responded significantly to PDGF-BB, with a three- to sixfold increase in thymidine incorporation over 72 hours of exposure, and there was a significant overall growth-stimulating effect of PDGF-BB in the 10 tumor specimens tested. In the last set of experiments, the functionality of the PDGF-β-R was determined by examining the induction of the proto-oncogene c-fos by PDGF-BB in meningioma cell cultures. A significant increase in c-fos protein was observed 3 hours after PDGF-BB addition.

These findings demonstrate that PDGF-A, PDGF-B, and PDGF-β-R are expressed in meningiomas and suggest that the β receptor is functional: when it is activated, c-fos levels are increased, and an increase in meningioma cell division is observed after the addition of PDGF-BB. These studies support the hypothesis that PDGF acts as a growth factor in meningiomas.
Secretion of interleukin-6 by human meningioma cells: possible autocrine inhibitory regulation of neoplastic cell growth
Authors: Todo Tomoki , Adams Eric F. , Rafferty Brian , Fahlbusch Rudolf , Dingermann Theodor , Werner Herbert
Published: May 2009

✓ Using cell culture techniques, the authors have previously shown that human meningioma cells secrete an autocrine growth stimulator related to platelet-derived growth factor. Here, they further demonstrate potential autocrine inhibitory regulation of meningioma cell growth by interleukin (IL)-6. Constitutive IL-6 production was detected in all meningiomas studied, in the form of protein as well as IL-6-specific messenger ribonucleic acid. The IL-6 immunoreactivity in conditioned medium from three different meningioma cultures eluted from a Sephadex G-100 column was evidenced by a single peak corresponding to a molecular weight of about 32 kD. Interleukin-6 secretion was remarkably stimulated by tumor necrosis factor-α, IL-1β, and IL-4, and was also influenced by a combination of epidermal growth factor and bromocriptine. Recombinant IL-6 exhibited a significant dose-dependent inhibitory effect on meningioma cell proliferation. The maximum effect was observed at concentrations of 10 to 100 pg/ml, with the decrease in thymidine incorporation ranging from 21% to 35% versus control. Addition of an anti-IL-6 antibody enhanced the growth-stimulating effect of meningioma-derived conditioned medium. The rate of IL-6 secretion tended to show an inverse correlation with meningioma growth rate. The results presented here and the previous results suggest that the regulation of meningioma cell proliferation is defined by a complex network of autocrine stimulation, autocrine inhibition, and influences from multiple exogenous factors.
High-resolution 1H-magnetic resonance spectroscopy of pediatric posterior fossa tumors in vitro
Authors: Sutton Leslie N. , Wehrli Suzanne L. , Gennarelli Laura , Wang Zhiyue , Zimmerman Robert , Bonner Kathy , Rorke Lucy B.
Published: May 2009

✓ High-resolution proton magnetic resonance (MR) spectroscopy was performed on perchlorate extracts of tumors (24 cases) or peritumoral vermis (five cases) obtained at surgery. Fifteen tumors were typical cerebellar astrocytomas and nine were posterior fossa primitive neuroectodermal tumors/medulloblastomas.

Spectra obtained from the five samples of peritumoral vermis revealed a pattern of metabolites similar to that reported for cerebellar tissue, but concentrations of most metabolites were low, perhaps due to dilution from peritumoral edema. The astrocytomas were characterized by high levels of valine, alanine, and choline, an increase in the choline:N-acetylaspartate (NAA) ratio, and a shift from glutamate to glutamine. Elevations in lactate, pyruvate, and glucose were the result of ischemia during sampling. The primitive neuroectodermal tumors/medulloblastomas were distinguished from astrocytomas by a greater increase in the choline:NAA ratio, a smaller decrease in the glutamate:glutamine ratio, and a relative increase in glycine, taurine, and inositol levels. These metabolic patterns may be of value diagnostically as in vivo MR spectroscopy achieves higher resolution.
Pneumatic nerve root compression: epidural gas in association with lateral disc herniation
Authors: Cheng Theresa M. , Link Michael J. , Onofrio Burton M.
Published: May 2009

✓ Extreme lateral disc herniations are increasingly recognized as a cause of lumbar nerve root compression syndromes. This disorder often presents major diagnostic and therapeutic challenges, especially in the presence of multiple degenerative changes and chronic back pain in elderly patients. The authors describe two patients with presentations and findings that have not been previously described in the literature. Both patients had histories of upper lumbar back and leg pain. Degenerative spine disease, gaseous degeneration of the intervertebral discs, and epidural gas in the lateral recesses were noted on imaging studies. However, because both patients had undergone prior epidural diagnostic and therapeutic procedures, the epidural gas in the lateral recesses could be attributed either to gaseous disc degeneration or to the previous intraspinal procedures. One patient was found to have a large, far lateral extruded disc fragment that contained air. The nerve root in the second patient was impaled by an unusual combination of a small extruded disc fragment as well as an air-filled sac that was surrounded by the walled-off fragment's capsule and which freely communicated with the gaseous degenerated disc space. The suspected mechanism of root compression is illustrated and discussed. The possibility of disc herniation should be seriously considered in cases of nerve root compression in which epidural gas is present, especially those associated with gaseous degenerated discs.
Malignant meningioma in Gorlin's syndrome: cytogenetic and p53 gene analysis
Authors: Albrecht Steffen , Goodman J. Clay , Rajagopolan Sri , Levy Moise , Cech David A. , Cooley Linda D.
Published: May 2009

✓ Gorlin's syndrome, also known as multiple basal cell carcinoma syndrome, is a familial tumor condition with autosomal-dominant inheritance. Patients develop multiple basal cell carcinomas beginning in childhood. They also have a typical dysmorphic facies, skeletal malformations, and a particular type of epithelial cyst of the jaws. Recent evidence localizes a Gorlin's syndrome locus on chromosome 9 at band q31. Both tumors and malformations of the central nervous system occur with Gorlin's syndrome. Medulloblastoma is the primary brain tumor most frequently associated with this syndrome; over 40 such cases have been reported. However, only seven cases of meningioma associated with Gorlin's syndrome have been described.

The authors report the case of a woman with Gorlin's syndrome whose mother and maternal grandfather also had the condition. The patient was found to have a medulloblastoma at 4 years of age and presented with a large bifrontal meningioma at 19 years of age. The meningioma was histologically malignant and had a complex karyotype with multiple translocations including a t(5;9) with the breakpoint on chromosome 9 located at 9q32. The constitutional karyotype of the mother was normal. No mutations of exons 5 to 9 of the p53 gene were detected using single-stranded conformational polymorphism analysis.
Indolent granulomatous angiitis
Authors: Johnson Mahlon D. , Maciunas Robert , Creasy Jeffrey , Collins Robert D.
Published: May 2009

✓ Granulomatous angiitis is a rare, treatable central nervous system vasculitis. Prompt diagnosis may be thwarted by protean presenting symptoms, an indolent clinical course, and atypical neurological findings. The authors describe a case of indolent granulomatous angiitis in which the patient presented with cerebellar signs and tissue changes suggestive of an atypical cerebellar infarction. After several years of remissions and relapses, repeat evaluation and biopsy disclosed granulomatous angiitis both in remote infarctions and in new cortical lesions. The clinical course and neuroradiological and pathological findings are compared with previous reports of fulminant and indolent granulomatous angiitis.
The physiological basis of concussion: 50 years later
Authors: Walker A. Earl
Published: May 2009

✓ In this brief narrative, the author compares what is known today about the physiological basis of concussion with the results of studies described 50 years ago in the Journal of Neurosurgery. The author was a member of the team that originally reported these findings in the first volume of the Journal of Neurosurgery.
Spinal cord tumors in children: long-term results of combined surgical and radiation treatment
Authors: O'Sullivan Catriona , Jenkin R. Derek , Doherty Mary A. , Hoffman Harold J. , Greenberg Mark L.
Published: May 2009

✓ The authors report a series of 31 children under 17 years of age with primary spinal cord tumors who underwent radiation treatment following decompression laminectomy with or without tumor resection between 1959 and 1990. The tumors consisted of 15 astrocytomas, 11 ependymomas, one mixed glioma, one ganglioglioma, and three of unknown histology. Ten- and 20-year survival rates and 10- and 20-year relapse-free survival rates for the 28 patients with known histology were 80% and 53%, and 73% and 67%, respectively. Eleven patients (35%) had no resection, 14 (45%) had a partial resection, and six (19%) had a grossly complete resection. Eight patients (26%) are dead: five due to recurrent tumor, two due to a second malignant tumor, and one due to intercurrent disease. Primary tumor relapse or progression occurred in nine patients (29%), four of whom were salvaged. A second malignant tumor developed in four patients (13%), two of whom died. Local control of the tumor was finally achieved in 26 cases (84%), despite either grossly incomplete or no resection in 25 of these cases (81%). These statistics suggest that radiation treatment without resection may achieve long-term control in children with astrocytoma or ependymoma of the spinal cord.
Terminal syringohydromyelia and occult spinal dysraphism
Authors: Iskandar Bermans J. , Oakes Jerry , McLaughlin Colleen , Osumi Alan K. , Tien Robert D.
Published: May 2009

✓ Terminal syringohydromyelia is a cystic dilatation of the lower third of the spinal cord. The authors describe its incidence and characteristics, its frequent association with occult spinal dysraphism, and its clinical significance and need for surgical treatment. All 143 cases of occult spinal dysraphism treated at the Duke University Medical Center between 1972 and 1992 were reviewed. A terminal syrinx was found in 24 (27%) of the 90 cases that were evaluated by magnetic resonance (MR) imaging. In contrast, three (6.2%) of 48 cases evaluated by myelography and postmyelographic computerized tomography had a syrinx documented.

The relative radiographic severity of the different syringes was estimated by using measurements of the syrinx and spinal cord on the MR images, classifying the cysts into large and small. Large syringes were frequently symptomatic, commonly presenting with pain, motor and sensory deficits of the lower extremities, scoliosis, and bowel and bladder dysfunction. Terminal syringohydromyelia with occult spinal dysraphic lesions was most often associated with tethered spinal cord from a tight filum terminale in the presence of an anorectal anomaly (67% of cases), meningocele manqué (54%), and diastematomyelia (38%). An infrequent association was seen with other spinal cord anomalies.

The results of surgical management of terminal syringohydromyelia were analyzed, highlighting the necessity and effectiveness of shunting the large cysts, especially in the setting of a progressive symptomatology. Of the 11 patients with shunts who underwent MR imaging, 10 showed either complete or significant resolution of the syrinx; all five patients who had presented with pain (mainly back pain) showed complete resolution of the pain after shunting; finally, one-third of patients with shunt placement had significant postoperative improvement in their neurological examination, whereas none worsened. It is stressed that terminal syringohydromyelia is an important pathological entity that should be considered in patients with occult spinal dysraphism, and treated surgically when clinically or radiographically significant.
Seasonal fluctuation in the incidence of intracranial aneurysm rupture and its relationship to changing climatic conditions
Authors: Chyatte Douglas , Chen Terence L. , Bronstein Kathryn , Brass Lawrence M.
Published: May 2009

✓ Seasonal and climatic variations have been linked to the occurrence of some types of cerebrovascular disease; however, the conditions that lead to intracranial aneurysm rupture are not known. The purpose of the present study was to determine whether seasonal and climatic conditions are related to intracranial aneurysm rupture.

Data provided by the Connecticut Health Information Management and Exchange were analyzed for all patients with a primary diagnosis of aneurysmal subarachnoid hemorrhage (SAH) for the fiscal years 1981, 1983, 1985, 1987, 1988, and 1989. Patient records were correlated with climatic conditions for the years 1981 to 1989 obtained from the National Climatic Data Center, National Oceanic and Atmospheric Administration, National Environmental Satellite Data, and Information Service.

During the time periods studied, 1487 patients with a primary diagnosis of aneurysmal SAH were treated by reporting hospitals. Seasonal variation in the incidence of aneurysmal SAH and admission clustering were observed but differed significantly between men and women. Men showed a single large peak in late fall (Roger's r = 11.5, p < 0.005), whereas women had an annual peak occurring in late spring (Roger's r = 10.3, p < 0.01). Substantial climatic change occurred during the 72 hours prior to 10 of the 14 clusters of men who were admitted (p < 0.01, Yates' corrected chi-square 7.33, df = 1). In contrast, clusters of women admitted were not related to preceding climatic change (p > 0.25, Yates' corrected chi-square 0.06, df = 1).

Hospital admissions for aneurysmal SAH display seasonal fluctuation, with women showing a different seasonal pattern from men. Changing climatic conditions precede aneurysm rupture in men but not in women, which suggests that weather is causally related to aneurysm rupture in men, and that factors that lead to aneurysm rupture in women may be different from those in men. These data do not explain why weather fronts or gradients are associated with aneurysm rupture in men.
Intracranial dural arteriovenous fistulae: angiographic predictors of intracranial hemorrhage and clinical outcome in nonsurgical patients
Authors: Brown Robert D. , Wiebers David O. , Nichols Douglas A.
Published: May 2009

✓ This long-term follow-up study of 54 patients clarifies the angiographic predictors of intracranial hemorrhage (ICH) and clinical outcome in individuals with unoperated intracranial dural arteriovenous fistulae (AVF's). All of these patients were examined at the Mayo Clinic between 1976 and 1989, and all available cerebral arteriograms were reviewed by a neuroradiologist. Follow-up information was obtained for 52 patients (96%) until death or treatment intervention, or for at least 1 year after diagnosis, with a mean follow-up period of 6.6 years.

Throughout this 6.6-year follow-up period, ICH related to dural AVF occurred in five of the 52 patients, for a crude risk of hemorrhage of 1.6% per year. The risk of hemorrhage at the time of mean follow-up examination was 1.8% per year. Angiographic examination revealed several characteristics that were considered potential predictors of ICH during the follow-up period. Lesions of the petrosal sinus and straight sinus had a higher propensity to bleed, although the small numbers in the series precluded a definite conclusion. A person suffering from a dural AVF with a venous varix on a draining vein had an increased risk of hemorrhage, whereas no hemorrhage was seen in the 20 patients without a varix (p < 0.05). Lesions draining into leptomeningeal veins had an increased occurrence of hemorrhage, although this increased risk was not statistically significant. Patients' initial symptoms were compared to those at follow-up evaluation. Pulsatile tinnitus improved in more than half of the 52 patients, and resolved in 75% of those showing some improvement. Individuals without a sinus or venous outflow occlusion at initial cerebral angiography were more likely to improve or remain stable (89%), whereas patients with an occlusion showed infrequent improvement (11%; p < 0.05).
High-energy phosphate metabolism in a neonatal model of hydrocephalus before and after shunting
Authors: da Silva Marcia C. , Drake James M. , Lemaire Claude , Cross Albert , Tuor Ursula I.
Published: May 2009

✓ The authors studied the effects of hydrocephalus on the high-energy phosphate metabolism of the brain and the impact of ventriculoperitoneal (VP) shunting on these changes in an experimental model of hydrocephalus. High-energy phosphate metabolism was analyzed using in vivo magnetic resonance (MR) imaging and 31P MR spectroscopy. Hydrocephalus was produced in 34 1-week-old kittens by cisternal injection of 0.05 ml of a 25% kaolin solution. Sixteen litter mates were used as controls. A VP shunt with a distal slit valve was implanted in 17 of the 34 hydrocephalic animals 10 days after induction of hydrocephalus. Both MR imaging and 31P MR spectroscopy were obtained 1 and 3 weeks after either kaolin or distilled water injection. Untreated hydrocephalic animals had marked dilatation of the lateral ventricles and periventricular edema. Magnetic resonance spectroscopy showed a significant decrease in the energy index ratio of phosphocreatine (PCR): inorganic phosphate (PI) and an increase in the PI:adenosine triphosphate (ATP) ratio. There was a direct correlation between the decrease in the energy index and ventricular size. Compared with preoperative scans, shunted animals showed no periventricular edema, and the ventricles decreased in size. Also, PCR:PI and PI:ATP ratios were within the levels of controls. This study suggests that neonatal hydrocephalus results in a mild hypoxic/ischemic insult that is treatable by VP shunting.
Cerebral damage caused by interrupted, repeated arterial occlusion versus uninterrupted occlusion in a focal ischemic model
Authors: Steinberg Gary K. , Panahian Nariman , Sun Go-Hua , Maier Carolina M. , Kunis David
Published: May 2009

✓ Temporary intracranial arterial occlusion is often utilized during the surgical treatment of intracranial aneurysms. Although numerous experimental studies have suggested that repetitive, brief periods of global ischemia cause more severe cerebral injury than a similar single period of global ischemia, this issue has not been extensively studied in relation to focal ischemia. It remains controversial whether it is safer to use brief periods of interrupted, temporary occlusion separated by reperfusion periods, or a more prolonged, single temporary occlusion. This question is addressed in studies on a rabbit model of transient, focal cerebral ischemia.

Sixteen anesthetized rabbits underwent transorbital occlusion of the left internal carotid, middle cerebral, and anterior cerebral arteries, with one of two paradigms: uninterrupted occlusion (1 hour of temporary occlusion followed by 5 hours of reperfusion in eight rabbits), or interrupted occlusion (three separate 20-minute periods of occlusion, with 10 minutes of reperfusion between occlusions, followed by 4 hours, 40 minutes of reperfusion in eight rabbits). Histopathological evaluation for ischemic neuronal damage and magnetic resonance imaging studies for ischemic edema were conducted 6 hours after the initial arterial occlusion.

The animals in the interrupted, repeated occlusion group showed a 59% decrease in the area of cortical ischemic neuronal damage (mean ± standard error of the mean 10.0% ± 1.7%) compared with the uninterrupted occlusion group (24.4% ± 5%, p = 0.016). There was no difference between the groups in the extent of striatal ischemic damage or area of ischemic edema. These results suggest that interrupted, repeated focal ischemia causes less cortical ischemic injury than uninterrupted transient ischemia of a similar total duration. Although caution should be exercised in extrapolating from these results to the clinical situation, they may have important implications for temporary arterial occlusion during intracranial surgery.
The effects of papaverine on phorbol dibutyrate-induced vasoconstriction in brain slice microvessels
Authors: Jin Yongcheng , Sagher Oren , Thai Quoc-Anh , Kassell Neal F. , Lee Kevin S.
Published: May 2009

✓ Papaverine (PPV) is a nonspecific vasodilator with widespread clinical uses in the treatment of arterial spasm. It has also been utilized in an attempt to reverse cerebral vasospasm. Recent angiographic results have demonstrated significant reversal of vasospasm in large vessels after selective intra-arterial application of PPV; however, these impressive results lacked good clinical correlation. In this study, phorbol dibutyrate was used to stimulate protein kinase C in an in vitro model of cerebral microvessels. Papaverine was found to elicit a dose-dependent exacerbation of phorbol dibutyrate-induced microvascular constriction in this model system. Because protein kinase C is thought to play a key role in the development of cerebral vasospasm, PPV-induced vasoconstriction represents a potentially important deleterious effect that may not be apparent on angiography. Such a constrictor response may compromise the beneficial vasodilatory effect seen with intra-arterial injection of PPV.
Reversal of chemoresistance in malignant gliomas by calcium antagonists: correlation with the expression of multidrug-resistant p-glycoprotein
Authors: Kiwit Jurgen Carl Walther , Hertel Anja , Matuschek Alexander E.
Published: May 2009

✓ Resistance to multiple drugs is often observed in malignant gliomas. The authors used a microtiter tetrazolium test to analyze primary in vitro chemoresistance and chemosensitivity of 15 early cultures of human malignant glioma exposed to 50 µg/ml (1,4-amino-2-methyl-5-pyrimidinyl)-methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU), 50 µg/ml cisplatin, 1 µg/ml vincristine, or combinations of these chemotherapeutic agents. Primary chemoresistance was observed in 87% of tumors for ACNU, in 87% for cisplatin, and in 83% for vincristine. All tumors were examined for expression of multidrug-resistant p-glycoprotein, a transport protein of 170,000 D, by means of immunohistochemical staining with the JSB-1 antibody on paraffinized tumor sections. Eight of 15 specimens (53%) showed positive staining for the monoclonal antibody. Primary chemoresistance was overcome by addition of the calcium antagonists verapamil or nimodipine to the cultures if the original tumor expressed p-glycoprotein (p < 0.01 for verapamil, p < 0.05 for nimodipine). In tumors not expressing p-glycoprotein, addition of calcium antagonists to the cell cultures did not influence primary chemoresistance. It is concluded from these data that addition of calcium antagonists to the adjuvant chemotherapy of malignant gliomas might overcome primary chemoresistance in tumors expressing the multidrugresistant phenotype.
Precocious puberty in a girl with an hCG-secreting suprasellar immature teratoma
Authors: Kitanaka Chifumi , Matsutani Masao , Sora Shigeo , Kitanaka Sachiko , Tanae Ayako , Hibi Itsuro
Published: May 2009

✓ Although precocious puberty is common in boys with human chorionic gonadotropin (hCG)-secreting brain tumors, it is extremely rare in girls. The authors describe a 6-year-old girl with an hCG-secreting suprasellar immature teratoma who presented with diabetes insipidus, increased intracranial pressure, and precocious puberty. On admission, breast budding was observed. The serum hCG level was 1230 mIU/ml. Both luteinizing hormone (LH) and follicle-stimulating hormone (FSH) remained below detectable levels, even after gonadotropin-releasing hormone stimulation. Serum estrogen and androgen were moderately elevated. After chemotherapy, breast budding disappeared with normalization of serum hCG.

It has been believed that hCG does not produce precocious puberty in girls in the absence of FSH, and this has been used as an explanation for the rarity of precocious puberty in girls with hCG-secreting brain tumors. However, it has also been reported that hCG has not only LH activity but also intrinsic, although weak, FSH-like activity. In the present case, this FSH-like activity was considered to have played a role in the development of precocious puberty. It is speculated that a very high level of serum hCG can produce precocious puberty in girls. The rarity of intracranial germ-cell tumors with a high potential of hCG secretion may be one of the reasons why hCG-induced precocious puberty is uncommon in girls.
Multiple dural metastases from a pituitary adenoma
Authors: Taylor William A. S. , Uttley David , Wilkins P. R.
Published: May 2009

✓ Only 12 cases of pituitary tumors that metastasized within the central nervous system have been reported. A further case is presented in which the histology of the multiple dural metastases remained identical to that of the original tumor, a pituitary adenoma. The authors discuss management of these rare lesions that appear histologically benign.
Frameless stereotaxy for surgery of the epilepsies: preliminary experience
Authors: Olivier André , Germano Isabelle M. , Cukiert Arthur , Peters Terry
Published: May 2009

✓ Frameless stereotactic techniques used in conjunction with three-dimensional images allow accurate planning and performance of a variety of neurosurgical procedures. The authors have used the frameless stereotactic Allegro Viewing Wand system to provide real-time correlation of the operating field and computerized images in 42 neurosurgical operations, including 31 epilepsy procedures. The system consists of an image-processing computer that creates three-dimensional and triplanar images; a mobile computer to display reformatted magnetic resonance images; and a hand-guided, articulated, position-sensing arm with a probe. At the start of the operation, the probe identifies the patient's facial and scalp features and correlates these with the computerized images. The position-sensing arm can then guide the operation and locate anatomical structures and lesions of interest. This system can be used to advantage in performing smaller craniotomies and intraoperatively locating anatomical structures and lesions to be removed. Postoperative magnetic resonance images demonstrate that this technique was accurate to within 3 mm in measuring the anteroposterior resection of fixed structures, such as hippocampus and corpus callosum. Disadvantages include longer preoperative preparation for data analysis and lack of both real-time computer analysis of tissue removal and angiographic data display. Preliminary experience suggests that the viewing wand system's advantages outweigh the disadvantages, and it is most helpful as an adjunctive navigational device in the microsurgical treatment of epilepsy.
Outcome for children with medulloblastoma treated with radiation and cisplatin, CCNU, and vincristine chemotherapy
Authors: Packer Roger J. , Sutton Leslie N. , Elterman Roy , Lange Beverly , Goldwein Joel , Nicholson H. Stacy , Mulne Lynn , Boyett James , D'Angio Giulio , Wechsler-Jentzsch Kaethe , Reaman Gregory , Cohen Bruce H. , Bruce Derek A. , Rorke Lucy B. , Molloy Patricia , Ryan Janise , LaFond Deborah , Evans Audrey E. , Schut Luis
Published: May 2009

✓ It has previously been reported in a single-institution trial that progression-free survival of children with medulloblastoma treated with radiotherapy and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU), cisplatin, and vincristine chemotherapy during and after radiotherapy was better than the outcome in children treated with radiotherapy alone. To better characterize long-term outcome and duration of disease control, this treatment approach was used for 10 years and expanded to three institutions. Sixty-three children with posterior fossa medulloblastomas were treated with craniospinal local-boost radiotherapy and adjuvant chemotherapy with vincristine weekly during radiotherapy followed by eight 6-week cycles of cisplatin, CCNU, and vincristine. To be eligible for study entry, patients had to be older than 18 months of age at diagnosis and have a subtotal resection, evidence of metastatic disease, and/or brainstem involvement. Patients younger than 5 years of age and without these poor risk factors who received reduced-dose craniospinal radiotherapy (2400 cGy) were also eligible for entry into the study. Sixty-three of 66 eligible patients (95%) were entered and placed on this treatment regimen. Forty-two patients had brainstem involvement, 15 had metastatic disease at the time of diagnosis, and 19 had received a subtotal resection. Progression-free survival for the entire group at 5 years is 85% ± 6%. Three children have succumbed to a second malignancy, and overall 5-year event-free survival is 83% ± 6%. Progression-free survival was not adversely affected by younger age at diagnosis, brainstem involvement, or subtotal resection. Five-year actuarial progression-free survival for patients who received reduced-dose radiotherapy was similar to that for patients receiving conventional-dose radiotherapy. Patients with metastatic disease at the time of diagnosis had a 5-year progression-free survival rate of 67% ± 15%, as compared to 90% ± 6% for those patients with localized disease at the time of diagnosis (p = 0.037). The authors conclude that overall progression-free survival remains excellent for children with posterior fossa medulloblastomas treated with this drug regimen. Chemotherapy has a definite role in the management of children with medulloblastoma. Further studies are indicated to define which subpopulations of children with medulloblastoma benefit from chemotherapy and what regimens are optimum in increasing disease control and, possibly, in reducing the amount of radiotherapy required.
Outcome after laminectomy for lumbar spinal stenosis
Authors: Tuite Gerald F. , Doran Stephen E. , Stern Joseph D. , McGillicuddy John E. , Papadopoulos Stephen M. , Lundquist Craig A. , Oyedijo Dotun I. , Grube Susan V. , Gilmer Holly S. , Schork M. Anthony , Swanson Steven E. , Hoff Julian T.
Published: May 2009

✓ The pre- and postoperative lumbar spine radiographs of 119 patients who underwent decompressive lumbar laminectomy were studied to evaluate radiographic changes and to correlate them with clinical outcome. An accurate and reproducible method was used for measuring pre- and postoperative radiographs that were separated by an average interval of 4.6 years. Levels of the spine that underwent laminectomy showed greater change in spondylolisthesis, disc space angle, and disc space height than unoperated levels. Outcome correlated with radiographic changes at operated and unoperated levels.

This study demonstrates that radiographic changes are greater at operated than at unoperated levels and that some postoperative symptoms do correlate with these changes. Lumbar fusion should be considered in some patients who undergo decompressive laminectomy. The efficacy of and unequivocal indications for lumbar fusion can only be determined from randomized, prospective, controlled trials, however, and these studies have not yet been undertaken.
Update on the Cloward procedure: new instruments
Authors: Otero Vich José M.
Published: May 2009

✓ A series of 283 patients who suffered from cervical spondylosis, herniated disc, or traumatic pathology of the cervical spine were operated on using an anterior approach. Intersomatic arthrodesis was performed in 350 cases; in every case, a threaded bone graft was screwed into the intervertebral orifice using the technique described by the author. Fusion was achieved within 6 months in 93% of cases with 92 autologous grafts and in 81% of cases with 258 heterologous grafts.

In addition to the use of threaded intervertebral holes and threaded bone grafts, the Cloward technique was modified by the introduction of a set of new instruments, which largely replaced the ones previously in use. These included a low-speed motor with different drills and trephines, a trephine guide retractor, and an intersomatic retractor.
Shunt failure without ventriculomegaly proclaimed by ophthalmic findings
Authors: Katz David M. , Trobe Jonathan D. , Muraszko Karin M. , Dauser Robert C.
Published: May 2009

✓ Four patients who developed increased intracranial pressure from ventricular shunt failure suffered a delay in diagnosis because magnetic resonance imaging of the brain did not show ventriculomegaly and because ophthalmic findings were initially overlooked or misinterpreted. None of the patients had the conventional manifestations of shunt failure: severe headache, nausea, vomiting, and depressed consciousness. Three patients suffered marked, permanent vision loss from chronic papilledema. These cases affirm that increased intracranial pressure may occur in shunt dependency without producing either conventional clinical symptoms or signs on imaging of the brain. Because ophthalmic manifestations may be the major clues to diagnosis, and because irreversible loss of vision is possible if these clues are overlooked, consideration should be given to periodic ophthalmological examination of shunt-dependent patients.
Enzymatic barrier protects brain capillaries from leukotriene C4
Authors: Black Keith L. , Baba Takehiko , Pardridge William M.
Published: May 2009

✓ Leukotriene C4 (LTC4) increases vascular permeability in systemic, brain tumor, and ischemic brain capillaries, but not in normal brain capillaries. This study examines whether the abundance of gamma-glutamyl transpeptidase (γ-GTP) in normal brain capillaries might act as an enzymatic barrier to vasoactive leukotrienes in the brain. Blood-brain barrier (BBB) permeability was determined by quantitative autoradiography using 14C-aminoisobutyric acid. Ischemia was produced by occluding the middle cerebral artery. Seventy-two hours after occlusion, γ-GTP activity in ischemic brain disappeared, and LTC4 (4-µg total dose), which was infused into the carotid artery ipsilateral to the occlusion, selectively increased permeability, Ki, approximately twofold within core ischemic tissue and adjacent tissue, compared to vehicle alone in seven brains (15.53 ± 6.03 vs. 7.29 ± 3.36, p < 0.05, and 8.76 ± 4.02 vs. 4.32 ± 2.65, p < 0.05, respectively). No effect on BBB was seen in nonischemic brain tissue. Twenty-four hours postocclusion, γ-GTP activity was still present, and LTC4 infusion did not increase permeability within ischemic tissue. However, inhibition of γ-GTP with acivicin allowed LTC4 to increase permeability even 24 hours after occlusion in ischemic core and adjacent tissue compared to vehicle alone in seven brains (17.21 ± 16.32 vs. 8.23 ± 6.58, p < 0.05, and 11.78 ± 7.96 vs. 4.56 ± 1.93, p < 0.01, respectively). Acivicin almost completely blocked both the histochemical activity of γ-GTP in brain capillaries and the metabolism of LTC4 in isolated bovine capillaries. These findings suggest that γ-GTP may help normal brain capillaries resist the vasoactive effects of LTC4. In contrast, γ-GTP is lost in injured brain capillaries, which allows LTC4 (in combination with other factors) to increase vascular permeability in ischemic brain and brain tumors.
Intracarotid infusion of RMP-7, a bradykinin analog: a method for selective drug delivery to brain tumors
Authors: Inamura Takanori , Nomura Tomojiro , Bartus Raymond T. , Black Keith L.
Published: May 2009

✓ The bradykinin analog, RMP-7, was investigated for its ability to selectively increase uptake of molecular tracers in RG2 glial tumors. When infused in low doses (0.1 µg/kg/min) through the intracarotid artery ipsilateral to RG2 gliomas in rats, RMP-7 significantly increased the permeability of tumor capillaries to methotrexate and to four other tracers of varying molecular weights, compared to intracarotid infusion of vehicle alone. Tracers used to examine permeability included radiolabeled α-aminoisobutyric acid (Mr 103 D), sucrose (Mr 342 D), methotrexate (Mr 454.5 D), inulin (Mr 5000 D), and dextran (Mr 70,000 D). Permeability was expressed as the unidirectional transfer constant, Ki (µl/gm/min). The permeability (Ki) of tumors in the RMP-7 group compared to the vehicle control group was as follows: α-aminoisobutyric acid, 35.3 ± 9.11 versus 12.7 ± 4.56 (p < 0.001); sucrose, 16.5 ± 3.83 versus 9.28 ± 3.12 (p < 0.05); methotrexate, 26.3 ± 10.3 versus 8.98 ± 6.78 (p < 0.005); inulin, 13.5 ± 3.23 versus 6.55 ± 4.32 (p < 0.005); dextran, 15.2 ± 3.42 versus 1.47 ± 1.24 (p < 0.001). The permeability of RG2 gliomas to high-molecular-weight dextran (70,000 D) was 10.3-fold higher in the RMP-7 group than in the vehicle control group. Intracarotid infusion of RMP-7 did not significantly increase the blood volume in tumor or brain tissue. The permeability of normal brain capillaries was unaffected by intracarotid infusion of 0.1 µg/kg/min RMP-7 relative to that achieved in tumor. These data support the idea that intracarotid infusion of RMP-7 will be a useful technique for selective delivery of antitumor compounds to brain tumors.
Quantitative imaging of estrogen and progesterone receptors, estrogen-regulated protein, and growth fraction: immunocytochemical assays in 52 meningiomas
Authors: Bouillot Pablo , Pellissier Jean-François , Devictor Benedicte , Graziani Noel , Bianco Nicole , Grisoli F. , Figarella-Branger Dominique
Published: May 2009

✓ Quantitative imaging of estrogen receptors (ER's), progesterone receptors (PR's), estrogen-regulated protein (pS2), and growth fraction (Ki67) immunocytochemical assays were performed in 52 meningiomas. The results were correlated with clinical (age, sex, hormonal status, and tumor volume and location) and morphological (histological types and grades) data.

The authors observed a lack of ER's in all meningiomas but the presence of PR's in 53% of these meningiomas. The immunoreactivity was restricted to tumor cell nuclei. The PR immunocytochemical assay was correlated with tumor location, histological type, histological grade, and pS2 immunocytochemical assay, but not with Ki67 immunocytochemical assay; high PR content was observed in cisternae, transitional, meningothelial, and low-grade meningiomas. Only 11 meningiomas showed more than 1% Ki67 immunoreactive nuclei. These meningiomas were usually located in the convexity and were of high histological grade. Estrogen-regulated protein immunoreactivity was observed in 34 meningiomas but the number of immunoreactive nuclei was low. The pS2 immunocytochemical assay was not related to clinicopathological features but was preferentially observed in PR-negative meningiomas.

The results of this study are compared with those previously reported, and the function and regulation of PR's in meningiomas is discussed. The results indicate that 1) regulation of PR's and pS2 proteins in meningiomas differs from regulation in estrogen-dependent tissues such as breast or endometrium; 2) interruption of hormonal therapy in women presenting with a meningioma is not absolutely necessary; 3) meningiomas have different biological properties according to their clinicopathological features; and 4) future studies of hormonal clinical trials should be performed on well-defined meningioma subgroups.