bluuebunny/crossref_metadata_2025 huggingface dataset:
On oscillation and nonoscillation properties of Emden-Fowler difference equations
Authors: Cecchi Mariella , Došlá Zuzana , Marini Mauro
Published: May 2009

A characterization of oscillation and nonoscillation of the Emden-Fowler difference equation $$
\Delta (a_n \left| {\Delta x_n } \right|^\alpha sgn\Delta x_n ) + b_n \left| {x_{n + 1} } \right|^\beta sgnx_{n + 1} = 0
$$ is given, jointly with some asymptotic properties. The problem of the coexistence of all possible types of nonoscillatory solutions is also considered and a comparison with recent analogous results, stated in the half-linear case, is made.
On the Drazin index of regular elements
Authors: Patrício Pedro , Costa António
Published: May 2009

It is known that the existence of the group inverse a
# of a ring element a is equivalent to the invertibility of a
2
a
− + 1 − aa
−, independently of the choice of the von Neumann inverse a
− of a. In this paper, we relate the Drazin index of a to the Drazin index of a
2
a
− + 1 − aa
−. We give an alternative characterization when considering matrices over an algebraically closed field. We close with some questions and remarks.
Wahl’s conjecture holds in odd characteristics for symplectic and orthogonal Grassmannians
Authors: Lakshmibai Venkatramani , Raghavan Komaranapuram , Sankaran Parameswaran
Published: May 2009

It is shown that the proof by Mehta and Parameswaran of Wahl’s conjecture for Grassmannians in positive odd characteristics also works for symplectic and orthogonal Grassmannians.
Sarcoidosis of the Thyroid Gland and Concomitant Hürthle Cell Adenoma: Case Report
Authors: Stojanoski Siniša , Gjorceva Daniela , Gruev Todor , Ristevska Svetlana , Ristevska Nevena , Tripunovski Toni
Published: May 2009

Sarcoidosis of the Thyroid Gland and Concomitant Hürthle Cell Adenoma: Case Report

Sarcoidosis is a multisystem disorder, characterized by the presence of noncaseating epithelioid-cell granulomas. The etiology remains unclear, although it is recognized as a disease of activated T lymphocytes. There is a diverse range of possible presentations with respiratory, gastrointestinal, reproductive, endocrine and other complications. The thyroid is an uncommon site of the disease with only 4% incidence according to some autopsy series. We present a case of a 55-year-old female patient with sarcoidosis of the thyroid gland and concomitant Hürthle cell adenoma. Upon performing a routine thyroid scintigraphy, a cold nodule has been observed. The diagnosis of the underlying disease was established by correlating the anamnesis data, patient's clinical history, fine needle aspiration biopsy and pathological examination of the thyroidectomy specimen. To our knowledge, the association has rarely been previously reported, indicating that thyroid involvement should be suspected in sarcoidosis patients who present with cold nodules.
Immunotoxins and central nervous system neoplasia
Authors: Hall Walter A. , Fodstad Øystein
Published: May 2009

✓ The poor prognosis associated with central nervous system (CNS) malignancy has led investigators to seek new, innovative treatment modalities. Immunotoxins, carrier molecules linked to toxic agents, combine high specificity for tumor-associated antigens with extreme potency. The rationale for both the development of these compounds and for their application to CNS neoplasia is explained. This report discusses the design and construction of immunoconjugates, using toxins that differ in their mechanism of action bound to ligands directed against various antigens. A comparison is made between the in vitro efficacy of standard chemotherapy and immunotoxins in glioblastoma- and medulloblastoma-derived cell lines. A review is included of the results of experiments in animals with leptomeningeal neoplasia, where prolongation of survival following intrathecal administration of immunotoxins has been reported. The obstacles encountered in clinical trials with other types of cancer are addressed and approaches to optimize the use of these novel agents in the context of treating malignant disease of the CNS are suggested.
Angiographic frequency of saccular intracranial aneurysms in patients with spontaneous cervical artery dissection
Authors: Schievink Wouter I. , Mokri Bahram , Piepgras David G.
Published: May 2009

✓ The pathogenesis of intracranial aneurysms and spontaneous cervical artery dissection is incompletely understood but a primary arteriopathy, possibly similar in both disorders, may be of importance. To investigate the frequency of intracranial aneurysms in patients with spontaneous cervical artery dissection, the angiograms of 164 patients who were diagnosed at the Mayo Clinic as having spontaneous extracranial carotid or vertebral artery dissection were reviewed. Thirteen intracranial aneurysms were detected in nine (5.5%) of the 164 patients: eight (8.8%) of the 91 female patients and one (1.4%) of the 73 male patients. The frequency of intracranial aneurysms in these patients was significantly higher (p < 0.01) than that observed in a recent angiographic study from the same institution, estimating the frequency of intracranial aneurysms in the general population (1.1%). The significance of these findings is discussed.
Significance of positive Queckenstedt test in patients with syringomyelia associated with Arnold-Chiari malformations
Authors: Tachibana Shigekuni , Iida Hideo , Yada Kenzoh
Published: May 2009

✓ Ten patients with syringomyelia associated with Arnold-Chiari Type I malformations were evaluated. In each patient, a manometric Queckenstedt test was performed with the neck in various positions. No patient showed evidence of a block to the flow of cerebrospinal fluid (CSF) with the neck in the extended position; however, all showed a complete CSF block with the neck in a flexed position. Posterior fossa decompression with a C1–2 laminectomy was performed in nine cases, after which Queckenstedt test demonstrated free CSF communication in all nine with the neck in extension, in a neutral position, and in flexion. Postoperative magnetic resonance imaging showed shrinkage of the syrinx in the patients who underwent surgery. It is suggested that obstruction of the CSF pathway at the foramen magnum produced by neck movement is of importance in the formation and progression of a syrinx.
Intravenous fluid tonicity: effect on intracranial pressure, cerebral blood flow, and cerebral oxygen delivery in focal brain injury
Authors: Shackford Steven R. , Zhuang Jing , Schmoker Joseph
Published: May 2009

✓ An investigation into the role of intravenous fluid tonicity in determining intracranial pressure (ICP) after brain injury is described. The authors compare the results of infusion of a hypotonic fluid (Ringer's lactate, 270 mOsm/liter) to those of a hypertonic fluid (hypertonic sodium lactate, 500 mOsm/liter) in a porcine model of focal cryogenic brain injury. Hemodynamic parameters (ICP, regional cerebral blood flow (CBF), and oxygen delivery) and serum osmolarity were measured every 3 hours for 24 hours after injury. At sacrifice, the water content of the lesioned and nonlesioned cortex was determined by specific gravity. The cryogenic injury produced a significant increase in ICP and a significant decrease in CBF in all experimental groups. Maintenance infusion of hypertonic sodium lactate for 24 hours resulted in significantly lower ICP, higher CBF and oxygen delivery, and higher serum osmolarity than Ringer's lactate infusion. Cortical water content in the area of the lesion was similar in both groups, but in the uninjured hemisphere it was significantly lower in the hypertonic group. These data suggest that hypertonic maintenance fluid improves intracranial compliance by dehydrating uninjured cortex. Improved CBF in the hypertonic group may be due to dehydration of cerebrovascular endothelium and erythrocytes. By reducing ICP and improving CBF, hypertonic fluid administration may thus reduce secondary brain injury after head trauma.
Remote congenital cerebral arteriovenous fistulae associated with aortic coarctation
Authors: Tomlinson Francis H. , Piepgras David G. , Nichols Douglas A. , Rüfenacht Daniel A. , Kaste Sue C.
Published: May 2009

✓ A neonate presented with anatomically discrete cerebral arteriovenous fistulae located in the right sylvian fissure and the cerebellar vermis that were initially detected by prenatal ultrasonography. Following delivery of the baby by Caesarean section, both malformations were treated by surgical obliteration. These intracranial vascular lesions were associated with cardiac anomalies and a periductal coarctation of the aorta, which was treated with a left subclavian rotational arterial pedicle repair. Follow-up examination of the infant at age 13 months demonstrated an excellent clinical result with normalization of the circulation. The pathophysiology of this syndrome is discussed and the literature reviewed.
Instrumentation for microsurgical osseous dissection
Authors: Carter L. Philip
Published: May 2009

✓ The use of the operating microscope has revolutionized the surgical approach to many neurosurgical diseases. The microscope has provided magnification, binocular vision, and excellent lighting in the depths of neurosurgical wounds, allowing the performance of exceedingly delicate procedures that were previously impossible. Occasionally, an operative approach demands microscopic bone dissection. Instrumentation has been developed for working with soft tissue, but special instruments for osseous dissection have not been available. A set of newly developed punches and curettes with a bayonetted offset is described. These keep the surgeon's hand out of the operating field and allow unimpeded visualization through the operating microscope. These prototype instruments have been used successfully in over 100 microscopic neurosurgical procedures.
Endocrinological evaluation of ACTH-secreting pituitary microadenomas: their location and α-melanocyte stimulating hormone immunoreactivity
Authors: Nagaya Takashi , Kuwayama Akio , Seo Hisao , Tsukamoto Nobuhiro , Matsui Nobuo , Sugita Kenichiro
Published: May 2009

✓ It has been hypothesized by Lamberts and coworkers in their analysis of 15 cases that adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas may be derived from either the anterior lobe or the intermediate lobe. The intermediate lobe type of Cushing's disease is thought to be controlled through a hypothalamic pathway and is characterized by hyperprolactinemia, suppressibility of Cortisol with bromocriptine, and lower sensitivity to dexamethasone. The authors investigated the validity of this hypothesis in 125 cases of ACTH-secreting pituitary microadenomas by analyzing the endocrine findings, the locations of the microadenomas, and α-melanocyte stimulating hormone (α-MSH) immunoreactivity in the adenoma cells. No significant differences in the basal hormone levels, Cortisol suppressibility with bromocriptine, sensitivity to dexamethasone, and recurrence rate were observed between patients with the microadenoma adjacent to the posterior lobe (considered typical of the intermediate lobe-derived tumor) or those with the microadenoma located in the anterior lobe. The locations of the microadenoma were not correlated with α-MSH immunoreactivity in the adenoma cells. No significant differences in endocrine findings were noticed between adenomas positive or negative for α-MSH. Thus, Cushing's disease cannot be simply divided into either the anterior lobe type or the intermediate lobe type by endocrinological evaluation as described by Lamberts, et al.
Variations in location of the arteries coursing between the brain stem and the free edge of the tentorium
Authors: Blinkov Samuil M. , Gabibov Gabib A. , Tanyashin Sergei V.
Published: May 2009

✓ The locations of arterial branches crossing the free edge of the tentorium were studied in 16 adult cadavers. Two positional variants of the superior cerebellar artery and four variants of the posterior cerebral artery were identified. The points at risk of compression by different types of transtentorial brain herniation were defined for both the arterial branches supplying the brain stem and the arterial branches supplying the cerebral hemispheres.
Intra-arterial urokinase for treatment of retrograde thrombosis following resection of an arteriovenous malformation
Authors: Sipos Eric P. , Kirsch Jeffrey R. , Nauta Haring J. W. , Debrun Gerard , Ulatowski John A. , Bell William R.
Published: May 2009

✓ Retrograde thrombosis of feeding arteries is a potentially catastrophic complication occasionally reported following resection of arteriovenous malformations (AVM's). No successful therapy for this condition, which causes postoperative stroke, has previously been reported. A case of retrograde thrombosis of the left middle cerebral artery immediately following resection of a parietal AVM is reported in a patient with a retained intra-arterial catheter from preoperative embolization. The administration of urokinase within 4 hours of surgery resulted in dramatic clinical and angiographic improvement without hemorrhagic complications. While urokinase is considered highly experimental in this setting, this case demonstrates that thrombolytic agents should be viewed as therapeutic options worthy of further investigation.
Thrombosis of difficult intracranial aneurysms by the endovascular placement of platinum-Dacron microcoils
Authors: Knuckey Neville W. , Haas Richard , Jenkins Ross , Epstein Mel H.
Published: May 2009

✓ Patients with symptomatic aneurysms that are not excluded from the cerebral circulation have a poor prognosis. Standard treatment is surgical exploration with direct clipping of the aneurysm. Because of their large size or relationship to the base of the skull, some aneurysms may not be suitable for direct surgical clipping and may require alternative treatment modalities. A prospective clinical and radiological study of seven patients treated with the endovascular placement of platinum-Dacron microcoils to exclude the aneurysm from the cerebral circulation is reported.

The seven patients ranged in age from 37 to 63 years; four were women. At completion of the endovascular procedure, total occlusion of the aneurysm with preservation of the parent artery had been achieved in four patients and 90% occlusion of the aneurysm in two. In the seventh patient, occlusion of the internal carotid artery resulted in the patient's death. At the 6-month follow-up review, both patients with an aneurysm less than 20 mm in size had persistent aneurysm thrombosis; however, the two patients with giant aneurysms had partial recanalization. Both required repeat thrombosis of their aneurysm with the placement of additional microcoils, one at 6 weeks and one at 6 months. These two patients have persistent aneurysm thrombosis at 12 months following their second procedure. The patient mortality rate for this study was 14%, while the procedure mortality/morbidity rate was 9%. It is concluded that thrombotic aneurysm therapy of difficult aneurysms is a safe procedure and will have a place in the treatment of selected aneurysms.
The role of endothelin-1 in the origin of cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage
Authors: Suzuki Ryuta , Masaoka Hiroyuki , Hirata Yukio , Marumo Fumiaki , Isotani Eiji , Hirakawa Kimiyoshi
Published: May 2009

✓ Plasma and cerebrospinal fluid (CSF) endothelin (ET)-1-like immunoactivity in 27 patients with aneurysmal subarachnoid hemorrhage (SAH) was measured serially by radioimmunoassay for 2 weeks after SAH onset. Mean ET-1-like immunoactivity levels in plasma of patients with SAH were highly elevated during the whole study period, while the levels in CSF of the same patients were not. Plasma ET-1-like immunoactivity levels in patients with SAH classified as Fisher computerized tomography (CT) Group 3 were higher than those in patients with SAH classified as Fisher CT Groups 1 and 2. There were no significant differences in plasma ET-1-like immunoactivity levels between the patient groups stratified by Hunt and Kosnik grade. In this series, plasma ET-1-like immunoactivity levels in the 12 patients with vasospasm were higher than those in the 15 patients without vasospasm during the 1st week; CSF ET-1-like immunoactivity levels in patients with vasospasm were in the normal range on Days 0 to 3 after SAH onset, then became elevated on Days 5 to 7 and remained high until the end of the 2nd week. In contrast, CSF ET-1-like immunoactivity levels in patients without vasospasm were within the normal range during the entire period of study. The time course of the occurrence of vasospasm and that of the increase in CSF ET-1-like immunoactivity coincided precisely. The possible role of endogenous ET-1 in the pathogenesis of vasospasm due to SAH is discussed.
Temporal lobe tumor demonstrating ganglioglioma and pleomorphic xanthoastrocytoma components
Authors: Furuta Akiko , Takahashi Hitoshi , Ikuta Fusahiro , Onda Kiyoshi , Takeda Norio , Tanaka Ryuichi
Published: May 2009

✓ The case is reported of a 16-year-old boy with a left temporal lobe tumor composed of a ganglioglioma and a pleomorphic xanthoastrocytoma. Histologically, the tumor had two different components. One component involved the cortex of the left posterior temporal lobe and showed an aggregation of neuronal cells with an astroglial stroma. Ultrastructurally, numerous dense-cored vesicles, diagnosed as ganglioglioma, were found in the neuronal cells. The other component involved the adjacent cortex and white matter of the left anterior temporal lobe and the surrounding subarachnoid space. This was composed of pleomorphic cells with many multinucleated giant cells and occasional foamy cells. Most of the tumor cells were positive for glial fibrillary acidic protein. These features correspond well to earlier descriptions of pleomorphic xanthoastrocytoma. At 24 months following total tumor extirpation, the patient is alive and has had no evidence of tumor recurrence.
Isolated intramedullary spinal artery aneurysm presenting with quadriplegia
Authors: Handa Takashi , Suzuki Yoshio , Saito Kiyoshi , Sugita Kenichiro , Patel Sunil J.
Published: May 2009

✓ The case is presented of an isolated intramedullary posterior spinal artery aneurysm at the C-2 level in a 3-year-old girl. Quadriplegia related to probable intramedullary hemorrhage was the presenting symptom. Magnetic resonance imaging revealed findings consistent with an intramedullary vascular lesion, and vertebral angiography confirmed this to be an aneurysm of the posterior spinal artery. No associated vascular abnormalities were noted, and the aneurysm was successfully resected. Previous reports of isolated spinal aneurysms are reviewed.
Dorsal third ventricular cyst: an entity distinct from holoprosencephaly
Authors: Young Jacob N. , Oakes W. Jerry , Hatten H. Pall
Published: May 2009

✓ The treatment and subsequent developmental progress of six children with dorsal third ventricular cysts are described. This cystic malformation has a radiological appearance which is superficially similar to that of the dorsal cyst of alobar holoprosencephaly, especially when the third ventricular cyst is large. Indeed, previous reports have identified this abnormality as a form of holoprosencephaly. However, careful study reveals that the dorsal third ventricular cyst is a distinct entity both developmentally and clinically. The six patients in this series were effectively treated with shunts, and their subsequent developmental progress was assessed by means of the Prescreening Developmental Questionnaire-Revised as well as the Bayley Scales of Infant Development. The nomenclature and differences between this entity and the holoprosencephalies are reviewed. The authors conclude that dorsal third ventricular cysts have a developmental and clinical course more similar to that of arachnoid cysts than to that of the holoprosencephalies.
In situ photocoagulation of spinal dural arteriovenous malformations using the Nd:YAG laser
Authors: Strugar John , Chyatte Douglas
Published: May 2009

✓ Spinal dural arteriovenous malformations (AVM's) are the most common type of AVM involving the spinal cord in adults. Direct obliteration of the fistula nidus located in the dura is the preferred method of treatment. Five cases of spinal dural AVM were treated by open surgical exposure, microsurgical disconnection of the dural nidus from the coronal venous plexus, and in situ obliteration of the nidus using the Nd:YAG laser. Use of the Nd:YAG laser reduced nidus obliteration to a simple 10-minute technical exercise. All patients improved neurologically following surgery, and complete obliteration of all lesions was verified by delayed angiography. There were no permanent complications related to either the surgical exposure or the use of the Nd:YAG laser. Open surgical treatment of spinal dural AVM's using the Nd:YAG laser appears to be a safe, effective, and durable method of treating these lesions. Photocoagulation is discussed in the context of the other treatment modalities available.
Giant thrombosed vertebral artery aneurysm managed with extracranial-intracranial bypass surgery and aneurysmectomy
Authors: Wakui Kenji , Kobayashi Shigeaki , Takemae Toshiki , Kamijoh Yukihiro , Nagashima Hisashi , Muraoka Shinsuke
Published: May 2009

✓ A case is presented of a left giant thrombosed vertebral artery aneurysm in a 46-year-old man. The giant thrombosed aneurysm was successfully resected with trapping of the affected artery after right external carotid artery-posterior cerebral artery bypass surgery using a radial arterial graft. The clinical course is reported, and the details of the operative approach and techniques are discussed.
Significance of gadolinium-enhanced magnetic resonance imaging in differentiating spinal cord radiation myelopathy from tumor
Authors: Yasui Toshihiro , Yagura Hisatoshi , Komiyama Masaki , Fu Yoshihiko , Nagata Yasunori , Tamura Katsuhiko , Khosla Virender Kumar , Hakuba Akira
Published: May 2009

✓ A young woman with a fourth ventricular ependymoma underwent radiotherapy following tumor excision. Twenty months later she developed a progressive neurological deficit at the C-2 vertebral level. Gadolinium-enhanced magnetic resonance imaging, showed an intramedullary lesion at the C-2 level. Although radiation myelopathy was suspected, tumor recurrence could not be excluded. Re-exploration and histopathology both confirmed a diagnosis of radiation myelopathy. A retrospective review of the case indicated findings favoring radiation myelopathy. The pertinent literature is reviewed and the findings discussed.
Resection of dominant opercular gliosis in refractory partial epilepsy
Authors: Obana William G. , Laxer Kenneth D. , Cogen Philip H. , Walker John A. , Davis Richard L. , Barbaro Nicholas M.
Published: May 2009

✓ Frontal opercular gliosis in the dominant hemisphere caused medically refractory partial epilepsy in two patients. Both patients were aphasic during their seizures, but otherwise had normal speech. Magnetic resonance images showed well-demarcated lesions resembling tumors in each patient; on heavily T2-weighted images, the lesions were hyperintense compared with normal brain. Cortical mapping with subdural grids localized speech to the area of the lesions; therefore, the resections were performed under local anesthesia and speech was tested throughout the procedure. Postoperatively, both patients were seizure-free and had no new neurological deficits. Well-demarcated lesions, even in the dominant operculum, can be safely removed in patients with medically refractory partial epilepsy.
Cerebral sparganosis diagnosed and treated with stereotactic techniques
Authors: Tsai Ming-Dar , Chang Chen-Nen , Ho Yat-Sen , Dah-Jium Wang Alexander
Published: May 2009

✓ Infestation of the central nervous system with sparganum, the larva of Spirometra mansoni, is rare. Only 27 cases have been reported in the literature; however, the true incidence might be underestimated. Two cases are reported that were definitively diagnosed by stereotactic biopsy techniques. Without a positive histological diagnosis, the first case would have been diagnosed as having a metastatic brain tumor and a course of radiotherapy would probably have been initiated. Differentiation between granuloma of cerebral sparganosis and brain tumors such as meningiomas, gliomas, and metastatic tumors is often difficult before operation. Detailed magnetic resonance imaging might offer some help in such cases. Emphasis is placed on the increasing importance of stereotactic surgery in the diagnosis and treatment of an intracerebral mass lesion, including cerebral sparganosis.
Herbert Olivecrona: founder of Swedish neurosurgery
Authors: Ljunggren Bengt
Published: May 2009

✓ Herbert Olivecrona (1891–1980) singlehandedly founded Swedish neurosurgery. At the International Congress in Neurology in Bern in August, 1931, Harvey Cushing invited the cream of the world's medical society to a private banquet. Among the 28 specially invited guests was Herbert Olivecrona. At 40 years old, Olivecrona took his seat with pioneers such as Otfrid Foerster, Percival Bailey, Hugh Cairns, Geoffrey Jefferson, and Sir Charles Sherrington. This suggests that Cushing was impressed by the Swedish aristocrat's didactic deeds when he visited the Serafimer Hospital in Stockholm 2 years earlier. During the mid-1920's, the radiologist Erik Lysholm greatly improved the technique of ventriculography and, challenged by Olivecrona, his diagnostic neuroradiology became of superior quality. In the early 1930's, utilizing technical innovations of his own, Lysholm became a master at demonstrating and localizing posterior fossa tumors, which Olivecrona then operated on. Olivecrona's clinic became the mecca to which many scholars, thirsting for more knowledge, went on a pilgrimage. The international reputation of the clinic was founded, not on epoch-making discoveries, but by the resolute and practical application of methods already launched elsewhere and the exemplary organization that Olivecrona had established in collaboration with Lysholm. In spite of hardships and primitive working conditions, the clinic at the Serafimer Hospital gradually developed into the ideal prototype for a modern neurosurgical department. Olivecrona trained many colorful personalities who later were to lay the foundation for neurosurgery in their home countries; these included Wilhelm Tönnis of Germany, Edvard Busch of Denmark, and Aarno Snellman of Finland. Olivecrona was a true pioneer who made major contributions in practically all fields of conventional neurosurgery.
Local protective effects of nerve growth factor-secreting fibroblasts against excitotoxic lesions in the rat striatum
Authors: Frim David M. , Short M. Priscilla , Rosenberg William S. , Simpson Joseph , Breakefield Xandra O. , Isacson Ole
Published: May 2009

✓ Neurotrophic factors, such as nerve growth factor (NGF), in addition to their role in neuronal development, have protective effects on neuronal survival. Intracerebral implantation of cells genetically altered to secrete high levels of NGF is also found to promote neuronal survival in experimental lesioning models of the brain. The range of activity for such biological delivery systems has not yet been well described either spatially or temporally. Therefore, the authors chose to study the local and distant protective effects of an NGF-secreting rat fibroblast cell line implanted in an excitotoxic lesion model of Huntington's disease. They found that preimplantion of NGF-secreting fibroblasts placed within the corpus callosum reduced the maximum crosssectional area of a subsequent excitotoxic lesion in the ipsilateral striatum by 80% when compared to the effects of a non-NGF-secreting fibroblast graft, and by 83% when compared to excitotoxic lesions in ungrafted animals (p < 0.003). However, NGF-secreting cells placed in the contralateral corpus callosum failed to affect striatal lesion size significantly when compared to contralateral or ipsilateral non-NGF-secreting cell implants. Of note, fibroblasts were clearly visible within the graft site at 7 and 18 days after implantation; however, few cells within the grafts stained positively for NGF peptide or for the messenger ribonucleic acid (mRNA) encoding the transfected NGF gene-construct at either time point. These results show that biological delivery systems for NGF appear to have a profound but local effect on neuronal excitotoxicity, which will necessitate careful neurosurgical placement for maximum effect. Furthermore, the ability of this genetically altered cell line to synthesize NGF mRNA and peptide appears to decrease spontaneously in vivo, a characteristic that will need to be addressed before this method of biological delivery can be utilized as a treatment for chronic degenerative diseases.
Intracerebral polyposis
Authors: Reddy P. Kantha , Rao G. Prakash , Prakasham Andole , Purnanand Aila , Sulochana Chinthalaphani , Kumar R. S. Asok , Reddy Y. Ranga , Chandramala  , Indumathi Dittakavi
Published: May 2009

✓ A 25-year-old man presented with nontraumatic cerebrospinal fluid rhinorrhea and meningitis. On investigation, he was found to have a multiloculated intracerebral cystic lesion of the right frontal lobe with a bony lesion inside the cyst, just above the right cribriform plate. Surgery revealed multiple grape-like cystic pedunculated lesions with narrow stalks attached to a bony outgrowth which was adherent to the right cribriform plate. Macroscopically and microscopically, the excised lesions were similar to nasal polyps.
Improving the outcome of severe head injury with the oxygen radical scavenger polyethylene glycol-conjugated superoxide dismutase: a Phase II trial
Authors: Muizelaar J. Paul , Marmarou Anthony , Young Harold F. , Choi Sung C. , Wolf Aizik , Schneider Roberta L. , Kontos Hermes A.
Published: May 2009

✓ Formation of the oxygen radical superoxide anion is one of the final events of several metabolic pathways in the cascade that leads to delayed neuronal death after traumatic or ischemic brain injury. In the laboratory, scavenging of the superoxide anion with native superoxide dismutase (SOD) or polyethylene glycol (PEG)-conjugated SOD (PEG-SOD) has been shown to be beneficial in several types of traumatic and ischemic injury. Accordingly, PEG-SOD was utilized in a randomized controlled Phase II trial to evaluate its safety and efficacy in severely head-injured patients with a Glasgow Coma Scale score of 8 or less. At two institutions, 104 patients were randomly assigned to receive either placebo or PEG-SOD (2000, 5000, or 10,000 U/kg) intravenously as a bolus, an average of 4 hours after injury. Prognostic factors were evenly distributed in the four groups, except for mean age which was significantly higher in the group receiving 10,000 U/kg than in the placebo group (mean age 34 years vs. 25 years).

No complications attributed to the study medication were noted. The average intracranial pressure (ICP) was similar in the four groups, but the percentage of time during which ICP was above 20 mm Hg was less in the groups receiving 5000 or 10,000 U/kg of PEG-SOD. Patients in the group receiving 10,000 U/kg also required less mannitol for ICP control than the placebo group. Outcome was assessed using the Glasgow Outcome Scale at 3 and 6 months postinjury in 91 and 93 patients, respectively, by blinded observers not involved in the clinical management of the patients. At 3 months, 44% of patients in the placebo group were vegetative or had died, while only 20% of patients in the group receiving 10,000 U/kg of PEG-SOD were in these outcome categories (p < 0.03, multiple logistic regression test); at 6 months, these figures were 36% and 21%, respectively (p = 0.04). Differences in outcome between the placebo group and either of the other two dosage groups were not statistically significant. It is concluded that PEG-SOD was generally well tolerated and appears promising in improving outcome after severe head injury. A larger, multicenter, Phase III trial, using a higher dose (20,000 U/kg) compared to placebo and to 10,000 U/kg of PEG-SOD is planned.
Prospective study on the prevention of cerebral vasospasm by intrathecal fibrinolytic therapy with tissue-type plasminogen activator
Authors: Mizoi Kazuo , Yoshimoto Takashi , Takahashi Akira , Fujiwara Satoru , Koshu Keiji , Sugawara Takayuki
Published: May 2009

✓ The authors have evaluated the efficacy of postoperative intrathecal injections of tissue-type plasminogen activator (tPA) in preventing cerebral vasospasm in patients with a diffuse thick subarachnoid hemorrhage (SAH). The present study examined 105 patients who underwent direct surgery within 48 hours of SAH and whose computerized tomography (CT) findings were classified as Fisher CT Group 3. Patients showing diffuse thick subarachnoid blood clots on CT with greater than 75 Hounsfield units (HU) were included in the tPA therapy group and those with below 75 HU comprised the control group. The surgical method was the same in both groups, and both groups had cisternal drainage instituted. On the day following the operation, the tPA group was given an intrathecal injection of tPA (2 mg), and this was continued for several days until all of the cisterns exhibited low density on CT scans. Follow-up angiography showed that 26 cases (87%) in the tPA group had no vasospasm, three (10%) had moderate vasospasm, and one (3%) had severe vasospasm. All four patients showing spasm on angiography were asymptomatic, and there were no cases of delayed ischemic neurological deficits (DIND). In contrast, there were 11 cases (15%) with DIND in the control group. In the tPA group, there was one case of SAH caused by drainage catheter removal, one with a small epidural hematoma, and one with subgaleal fluid accumulation; all of these were treated conservatively with favorable results. Overall, there were no infectious complications related to cisternal drainage and intrathecal injection of tPA. These results indicate that multiple intrathecal injections of small doses of tPA are effective and safe in preventing vasospasm. On the basis of this experience, the authors conclude that injection of 2 mg of tPA daily for 5 days (a total of 10 mg) is effective in preventing the development of vasospasm.
Transient and repetitive rises in blood pressure synchronized with plasma catecholamine increases after head injury
Authors: Shiozaki Tadahiko , Taneda Mamoru , Kishikawa Masanobu , Iwai Atsushi , Sugimoto Hisashi , Yoshioka Toshiharu , Sugimoto Tsuyoshi
Published: May 2009

✓ The authors report two patients with repetitive episodes of acute transient rise in blood pressure synchronized with increases in plasma catecholamine after severe head injury. In both cases, the paroxysmal hypertension occurred suddenly on the 2nd day posttrauma, and its frequency declined gradually, disappearing with time. The pathophysiological basis of this peculiar clinical manifestation is discussed.
Antonio Pacchioni (1665–1726): early studies of the dura mater
Authors: Brunori Andrea , Vagnozzi Roberto , Giuffrè Renato
Published: May 2009

✓ The clustering of arachnoid villi along the sagittal sinus forms what is known as “Pacchioni granulations.” These structures were first described in 1705 by Antonio Pacchioni, an Italian scientist. Pacchioni was born in Reggio Emilia, Italy, in 1665, and there he received his degree in medicine. Later he moved to Rome where he built a successful career dedicated to medical practice, research, and teaching. He became a friend of some of the leading scientists of his age: Lancisi, Malpighi, and Morgagni, among others. He devoted himself to elucidating the structure and function of dura mater, and in his studies often used the new technique of maceration of anatomical specimens in various fluids. Among Pacchioni's written works, the Dissertatio Epistolaris de Glandulis Conglobatis Durae Meningis Humanae (1705) deserves the greatest consideration as it contains the first description of arachnoid granulations. He compared dura to cardiac muscle and attributed to its “glandulae” (glands) the faculty of secreting lymph for lubrication of the sliding movements between meninges and brain during contractions. Three centuries after Pacchioni's death in Rome in 1726, the fine structure of arachnoid villi has not been fully elucidated; moreover, many questions related to mechanisms underlying cerebrospinal fluid absorption remain unanswered.
A randomized trial of nicardipine in subarachnoid hemorrhage: angiographic and transcranial Doppler ultrasound results
Authors: Haley E. Clarke , Kassell Neal F. , Torner James C. , _ _
Published: May 2009

✓ Calcium antagonist drugs were proposed for use in patients with recent aneurysmal subarachnoid hemorrhage (SAH) because of their ability to block the effects of a wide variety of vasoconstrictor substances on cerebral arteries in vitro. It was suggested that these agents might, therefore, be useful in ameliorating cerebral vasospasm and its ischemic consequences which frequently complicate SAH. This hypothesis was tested in an arm of a randomized double-blind placebo-controlled trial of high-dose intravenous nicardipine in patients with recently ruptured aneurysms. Participating investigators were required to send selected copies of all admission and follow-up angiograms obtained between Days 7 and 11 following hemorrhage (the peak period of risk for vasospasm) to the Central Registry of the Cooperative Aneurysm Study for blinded interpretation and review for the presence and severity of angiographic vasospasm. In centers with transcranial Doppler ultrasound (TCD) capabilities, middle cerebral artery (MCA) mean flow velocities were measured and recorded.

Angiograms obtained between Days 7 and 11 were available for 103 (23%) of 449 patients receiving nicardipine and 121 (26%) of 457 receiving placebo. There was a balance of prognostic factors for vasospasm between the groups. Fifty-one percent of placebo-treated patients had moderate or severe vasospasm on “Day 7–11 angiograms” compared to 33% of nicardipine-treated patients. This difference is statistically significant (p < 0.01). Sixty-seven (49%) of 137 placebo-treated patients examined with TCD between Days 7 and 11 had mean MCA flow velocities exceeding 120 cm/sec compared to 26 (23%) of 112 nicardipine-treated patients (significant difference, p < 0.001). These data suggest that high-dose intravenous nicardipine reduces the incidence and severity of delayed cerebral arterial narrowing in patients following aneurysmal SAH.
Platelet-activating factor and cerebral vasospasm following subarachnoid hemorrhage
Authors: Hirashima Yutaka , Endo Shunro , Otsuji Tsuneo , Karasawa Ken , Nojima Shoshichi , Takaku Akira
Published: May 2009

✓ This study examines whether platelet-activating factor (PAF) is involved in the occurrence of vasospasm after subarachnoid hemorrhage (SAH). A vasospasm model was produced in rabbits, with animals in six experimental groups receiving two subarachnoid injections of autologous arterial blood with the addition of one of the following: saline (Control Group 1), 25% dimethyl sulfoxide (Control Group 2), PAF (1, 2.5, 5, or 10 µg), CV6209 (10 or 100 µg), BN52021 (10 or 100 µg), or anti-PAF immunoglobulin G (IgG, 50 or 500 µg). No significant differences were detected between Control Groups 1 and 2 with regard to neurological deterioration and basilar artery constriction after SAH was induced. Administration of PAF together with autologous blood aggravated neurological deficits in a dose-dependent manner (r = 0.724, p < 0.001) and produced basilar artery constriction at two doses each of 2.5 µg (p < 0.05), 5 µg (p < 0.01), and 10 µg (p < 0.01). Neurological deterioration was prevented in rabbits receiving an intracisternal administration of either PAF antagonist CV6209 or BN52021 or anti-PAF IgG (p < 0.01 at a total dose of 20 µg and p < 0.05 at a total dose of 200 µg CV6209, p < 0.01 at total doses of 20 and 200 µg BN52021, and p < 0.01 at total doses of 100 and 1000 µg anti-PAF IgG). A reduction in basilar artery constriction was achieved by the injection of anti-PAF IgG (p < 0.05 at total doses of 100 and 1000 µg). Histological examination at autopsy on Days 14 to 21 showed mainly ischemic changes in the brain, including selective neuronal necrosis and cerebral infarction. The control and PAF groups showed marked ischemic changes. On the other hand, no ischemic changes were noted in the anti-PAF IgG group, and only 9% of animals in the CV6209 group and 25% in the BN52021 group demonstrated selective neuronal necrosis or infarction. This study thus provides evidence to support the role of PAF in the pathogenesis of vasospasm after SAH.
The expression of deafferentation dysesthesias reduced by dorsal root entry zone lesions in the rat
Authors: Rossitch Eugene , Abdulhak M. , Ovelmen-Levitt Janice , Levitt M. , Nashold Blaine S.
Published: May 2009

✓ Extensive longitudinal lesions of the dorsal root entry zone (DREZ) are effective in relieving some chronic deafferentation pain in humans. A deafferentation syndrome follows C5—T2 dorsal root ganglionectomies in rats. The syndrome consists of biting and scratching the completely and partially denervated limb areas, respectively.

This study examines the effect of DREZ lesions on the deafferentation syndrome in the rat. Of 37 rats, 24 underwent C5—T2 ganglionectomies only, five received C4—T3 micromechanical DREZ lesions only, and eight underwent ganglionectomies plus simultaneous DREZ lesions. The animals were observed for 45 days postoperatively. Histological analysis of the spinal cord lesions was performed.

All rats with ganglionectomies alone exhibited the deafferentation syndrome; however, no rats with DREZ lesions alone showed this feature. Only 25% of rats with combined ganglionectomies and DREZ lesions exhibited the deafferentation syndrome in the first 30 days, whereas 80% of the animals with ganglionectomies only did so. Although 75% of the animals with combined lesions eventually bit the insensitive forepaw, this behavior was significantly attenuated: the day of onset was delayed and the extent of self-mutilation was reduced. Postmortem histological examination of the DREZ lesions indicated a close association between the completeness of the dorsal horn destruction and the reduction or prevention of self-mutilation.

These data support the validity of the animal model and also the hypothesis stating that the deafferentation syndrome results from abnormal spontaneous neural activity in the dorsal horn. Moreover, the variability of the histological findings in these experiments stresses the importance of making contiguous and complete dorsal horn lesions in human DREZ surgery.
Effect of neonatal capsaicin treatment on neurogenic pulmonary edema from fluid-percussion brain injury in the adult rat
Authors: Levasseur Joseph E. , Patterson John L. , Garcia Claudia I. , Moskowitz Michael A. , Choi Sung C. , Kontos Hermes A.
Published: May 2009

✓ The frequent occurrence of acute death from pulmonary failure in experimental head injury studies on Sprague-Dawley rats prompted an investigation into the manner in which acute neurogenic pulmonary edema develops in these animals as a result of an applied fluid pressure pulse to the cerebral hemispheres. Studies were performed in adult animals using histamine H1 and H2 blocking agents, or in adult animals treated as neonates with capsaicin to destroy unmyelinated C-fibers. Recordings were made of either the pulmonary arterial or the right ventricular pressure, and the left atrial and femoral arterial pressures before, during, and after injury to provide a record of the hemodynamic response throughout the development of neurogenic pulmonary edema. Head injury triggered the almost immediate development of pressure transients with and without neurogenic pulmonary edema. All rats, regardless of treatment, reacted with nearly identical systemic arterial pressure responses; however, the pulmonary responses followed a time course that was independent of systemic arterial pressure changes. Acute neurogenic pulmonary edema was always associated with a substantial increase in pulmonary arterial and left atrial pressures; conversely, pressure increases of similar magnitude were not always associated with edema. Histamine H1 and H2 blockers significantly reduced the pulmonary pressure surges only in rats free of neurogenic pulmonary edema. All capsaicin-treated rats showed suppressed pulmonary pressure responses, normal lung water content, elevated lung surface tension, and significantly reduced levels of immunoreactive substance P in the spinal cord and vagus nerve. While the pressures cannot clarify how edema influences the observed hemodynamics, they do not support the view that edema is the direct consequence of pulmonary hypertension. It is proposed that neurogenic pulmonary edema is a functional disturbance provoked by adverse stimuli from outside the lungs and that in the rat the primary afferent fiber is essential to the production of this entity.
Neuronal heterotopia with capillary penetration of neurons and cortical dysplasia in a patient with complex partial seizures
Authors: Jay Venita , Becker Laurence E. , Otsubo Hiroshi , Hwang Paul , Hoffman Harold J. , Armstrong Derek C.
Published: May 2009

✓ Unusual pathological findings were encountered in a temporal lobectomy specimen from a 9-year-old boy with intractable complex partial seizures. Magnetic resonance imaging revealed an enlarged left temporal lobe, with diffuse high signal intensity over the cortex and poor gray-white differentiation on T2-weighted imaging; single-photon emission computerized tomography showed decreased blood flow. Active epileptiform discharges were identified in the left temporal lobe with focal slow waves and generalized epileptiform paroxysms. Pathologically, the cortex revealed changes of focal cortical dysplasia with extensive disorganization of neuronal morphology, layering, and orientation as well as focal polymicrogyria. The cortical-white matter junction was indistinct with extensive neuronal heterotopias in the white matter. Large pale balloon cells akin to those seen in tuberous sclerosis were found scattered within the cortex and white matter. The most striking finding was that of a heterotopic nodule in the white matter, which revealed abnormal neurons with penetration of cell bodies by capillaries. Ultrastructurally, there were no degenerative changes in these neurons, and this unusual phenomenon is attributed to a developmental disturbance affecting neuronal, glial, and vascular elements.
Selective endovascular techniques in the treatment of cerebral mycotic aneurysms
Authors: Khayata Mazen H. , Aymard Armand , Casasco Alfredo , Herbreteau Denis , Woimant France , Merland Jean Jacques
Published: May 2009

✓ The aim of this study was to evaluate the role of endovascular treatment for intracranial mycotic aneurysms. The clinical and angiographic features of three patients with endocarditic vegetation (two with Streptococcus viridans and one with Staphylococcus) were reviewed retrospectively. Patients were selected for this treatment according to the clinical setting and aneurysm location. In two cases, selective catheterization of a distal middle cerebral and posterior cerebral artery branch with a microcatheter followed by superselective amobarbital testing of the parent vessel was preliminary to the occlusion of that vessel with autologous clot or glue. The third patient was treated by selective occlusion of the aneurysm by intra-aneurysmal placement of platinum minicoils. Two patients presented with intracranial hemorrhage and in one the lesion was found on computerized tomography. All three aneurysms had been excluded from the circulation at the 6-month follow-up review. The only complication from the procedure, despite the septic nature and distal localization, was balloon deflation in one patient, who was successfully retreated with coils. Endovascular embolization is indicated in patients who are at risk of hemorrhage and cannot undergo the standard procedure. The superselective amobarbital test allows selection of patients who will tolerate distal vessel occlusion. This endovascular procedure represents a safe and effective treatment for these lesions.