bluuebunny/crossref_metadata_2025 huggingface dataset:
O6-Alkylguanine-DNA alkyltransferase and sensitivity to procarbazine in human brain-tumor xenografts
Authors: Schold S. Clifford , Brent Thomas P. , von Hofe Eric , Friedman Henry S. , Mitra Sankar , Bigner Darell D. , Swenberg James A. , Kleihues Paul
Published: May 2009

✓ The level of O6-alkylguanine-deoxyribonucleic acid (DNA) alkyltransferase (AT) was determined in 15 human brain-tumor xenografts in athymic mice. This enzyme is a primary intracellular repair mechanism for lesions produced at the O6 position of guanine by a wide range of alkylating agents, including nitrosoureas and procarbazine. Its activity ranged from undetectable in five tumor lines to 2338 fmol/mg protein in N-1941, a human glioblastoma xenograft. The sensitivity of 10 of these xenografts to procarbazine was determined and it was found that four of the five tumor lines with AT levels of more than 100 fmol/mg protein had growth delays after procarbazine treatment of less than 20 days, whereas all five lines with undetectable AT levels had growth delays of over 30 days. The primary cytotoxic DNA adduct produced by procarbazine (namely, O6-methylguanine) was found to be significantly higher in two sensitive lines with low AT levels than in a highly resistant line with a high AT level. These data suggest that the AT levels of individual brain tumors can be used as predictive indicators of their susceptibility to drugs that exert their antineoplastic effect primarily by O6-alkylation of guanine in nuclear DNA.
Spinal cord injury and the stress protein response
Authors: Gower David J. , Hollman Carol , Lee K. Stuart , Tytell Michael
Published: May 2009

✓ The heat shock or stress response is a highly conserved primary cellular response to injury. Synthesis of stress proteins (also called “heat shock proteins”) is an integral component of this response. Protection from various forms of sublethal stress following increased production of stress proteins has been demonstrated in a number of systems, including the retina. This immunocytochemical study demonstrates the synthesis, accumulation, and redistribution of the 70-kD stress protein following spinal cord injury in rats. The observations confirm that stress protein production is a fundamental feature of the molecular response of the spinal cord to injury, and raise the possibility that augmentation of this response could enhance posttraumatic neuronal survival.
Magnetic resonance imaging and 31P magnetic resonance spectroscopy for evaluating focal cerebral ischemia
Authors: Germano Isabelle M. , Pitts Lawrence H. , Berry Isabelle , Moseley Michael
Published: May 2009

✓ Recent advances in magnetic resonance (MR) imaging and MR spectroscopy (MRS) allow the noninvasive in vivo study of a variety of anatomical, physiological, and biochemical alterations that may occur in different cerebral pathologies. The authors have investigated the use of MR imaging and MRS to monitor the evolution of experimental focal cerebral ischemia in rats. Permanent focal cerebral ischemia was induced in 36 rats, and 12 normal rats were used as a control group. Changes in high-energy phosphate metabolites were followed in vivo using MRS during the 1st hour and at 3 and 6 hours after ischemic insult. Changes in in vivo MR images were evaluated at 1, 3, 6, 12, and 24 hours after ischemic insult. Significant decreases (p < 0.05) in phosphocreatine/inorganic phosphate ratios and intracellular pH values occurred immediately after the induction of ischemia. The presence of an infarcted area seen on MR images was a constant finding at 3 hours after ischemic insult, and was well defined and localized at 12 and 24 hours. The location of areas of infarction seen on MR images correlated well with areas identified histopathologically. The T1 and T2 MR relaxation times were significantly increased 3 hours after ischemic insult and remained prolonged for at least 24 hours. The results show that MR imaging is a sensitive method to measure cerebral infarction, and that MRS is a sensitive measure of changes that occur in the early phases of ischemia, perhaps when cellular changes may still be reversible. At 3 and 6 hours after the ischemic insult, however, 31P-MRS spectra may appear to be “normal” despite the presence of well-documented areas of infarction.
Management of juvenile spinal AVM's by embolization and operative excision
Authors: Spetzler Robert F. , Zabramski Joseph M. , Flom Richard A.
Published: May 2009

✓ A small group of spinal arteriovenous malformations (AVM's), most commonly present in children or young adults, are characterized by a large size, high flow, the presence of multiple feeders, and frequent extension to paraspinous structures. Cardiac output requirements may be significantly increased by these so-called “juvenile” malformations, and a bruit is commonly noted. This report describes the obliteration of a juvenile spinal AVM. Staging of embolization and operative procedures was used to obliterate the AVM successfully without morbidity.
Hypothalamic hamartoma
Authors: Nishio Shunji , Fujiwara Shigeru , Aiko Yasutaka , Takeshita Iwao , Fukui Masashi
Published: May 2009

✓ Two cases of hypothalamic hamartoma are presented. The first patient was a 4-year-old boy with precocious puberty, and the second was a 6-year-old boy with epileptic seizures. In both patients, clinical symptoms and signs appeared at the age of 2 years and progressed thereafter. Computerized tomography and magnetic resonance imaging in both cases disclosed a suprasellar mass lesion in continuity with the hypothalamus. Removal of the lesions affected the endocrinological status and/or seizure control. Pathological examination revealed the lesions to be composed of well-differentiated neuronal and glial cells. Immunohistochemical study demonstrated the presence of beta-endorphin, corticotropin-releasing factor, oxytocin, and neurofilament protein (210 kD) in the neuronal cells of the first patient, but no neuropeptides were detected in the second. Electron microscopic examination on the second patient disclosed the presence of many nonmyelinated and some myelinated neuronal processes containing dense-core and clear vesicles. The morphological characteristics and the role of surgery for this lesion are discussed.
Immunoreactive S-antigen in cerebrospinal fluid: a marker of pineal parenchymal tumors?
Authors: Korf Horst W. , Bruce Jeffrey A. , Vistica Barbara , Rollag Mark , Stein Bennett M. , Klein David C.
Published: May 2009

✓ This investigation evaluated the possibility that the occurrence of S-antigen in cerebrospinal fluid (CSF) might be used as a preoperative marker of pineal parenchymal tumors (pineoblastoma and pineocytoma). Such a marker could provide a means of preoperatively differentiating these neoplasms from pineal region tumors of other origin. The S-antigen, also known as the 48-kD protein or arrestin, is a highly antigenic protein originally found in the retina and pineal gland. In the retinal photoreceptors and submammalian pineal photoreceptors the protein is thought to be involved in phototransduction; its function in the mammalian pinealocyte is unknown. S-Antigen immunoreactivity also occurs in certain neoplastic cells of retinoblastomas, pineocytomas, pineoblastomas, and cerebellar medulloblastomas. This study included a group of 13 patients with tumors of the pineal region. Samples of CSF were obtained preoperatively and analyzed for the S-antigen using western blot technology. Tumor biopsy material was classified according to conventional neurohistological criteria and was also examined by immunocytochemical techniques for the presence of the S-antigen. S-Antigen immunoreactivity was found in the preoperative CSF of the one patient found to have pineocytoma; tumor tissue removed from this patient was the only neoplastic tissue examined in this study which contained S-antigen immunoreactive tumor cells. Furthermore, hydroxyindole-O-methyltransferase activity was detectable in the pineocytoma but not in three other pineal tumors, and melatonin levels in the CSF of the pineocytoma patient were the highest in the patient group examined. These preliminary results suggest that testing for S-antigen in CSF might be useful in characterizing and treating tumors of the pineal region and, when identified in conjunction with other markers, it might also help to better define pineal parenchymal tumors. This study needs confirmation with a larger number of patients. If this approach is eventually found to be a reliable predictor of pineal cell tumors, it may supplant the need for surgical biopsies before initiating appropriate adjunctive therapy.
Hyperfractionated radiation therapy for brain-stem glioma: a Phase I–II trial
Authors: Edwards Michael S. B. , Wara William M. , Urtasun Raul C. , Prados Michael , Levin Victor A. , Fulton Dorcas , Wilson Charles B. , Hannigan John , Silver Pamela
Published: May 2009

✓ Fifty-three patients (19 adults and 34 children) harboring brain-stem glioma were treated with hyperfractionated radiation therapy (100 cGy twice a day, 5 days/wk, to a total dose of 7200 cGy). For the entire group, the median time to tumor progression (TTP) was 59 weeks (adults 66 weeks, children 44 weeks) and the median survival time was 74 weeks (adults 92 weeks, children 64 weeks). Statistically significant prognostic factors associated with a decrease in TTP and median survival times (adults < children) were: patient's age, a clinical history of less than 2 months, widespread brain-stem dysfunction, and a diffuse tumor as seen on magnetic resonance imaging. A finding of glioblastoma multiforme at histological analysis was associated with a statistical trend toward poorer survival, but in general tumor histology was not predictive of outcome. No evidence of an increase in acute or delayed radiation toxicity was seen with this fractionation schedule and total dose. This study suggests that hyperfractionation prolongs the TTP and survival time for many patients with brain-stem glioma. However, there remains a group of patients who are only moderately helped by this technique and for whom more aggressive treatment is warranted.
Correlation of histopathological features and proliferative potential of gliomas
Authors: Germano Isabelle M. , Ito Masami , Cho Kyung G. , Hoshino Takao , Davis Richard L. , Wilson Charles B.
Published: May 2009

✓ One hundred fifty-two intracranial gliomas of various types were reviewed in order to correlate the histopathological features with the proliferative potential of each tumor as reflected by the bromodeoxyuridine (BUdR) labeling index (LI). Patients undergoing surgical removal of gliomas were given a 30-minute intravenous infusion of BUdR (150 to 200 mg/sq m) to label S-phase tumor cells. The tumor specimens were stained immunohistochemically for BUdR and processed for routine histopathological diagnosis. The BUdR LI was calculated as the percentage of labeled cells among cells analyzed. Twenty-seven histological features in three categories (degenerative, vascular, and cellular changes) were considered. A significantly higher BUdR LI (p < 0.05) was found in tumors with necrosis than in those without this feature; tumors with both coagulative and liquefactive necrosis had the highest BUdR LI (p < 0.05). Increased vascularity was also associated with a higher BUdR LI (p < 0.05). Although tumors with abnormal mitotic figures had a significantly higher BUdR LI than those without, the number of mitoses did not correlate with a higher BUdR LI. These results suggest that the number of mitoses is not a good indicator of tumor growth rate. Necrosis and increased vascularity should be heavily weighted in predicting the proliferative potential of individual gliomas.
A prospective study of cognitive function in children receiving whole-brain radiotherapy and chemotherapy: 2-year results
Authors: Packer Roger J. , Sutton Leslie N. , Atkins Thomas E. , Radcliffe Jerilynn , Bunin Greta R. , D'Angio Giulio , Siegel Kathy R. , Schut Luis
Published: May 2009

✓ As survival rates have risen for children with malignant primary brain tumors, so has the concern that many survivors have significant permanent cognitive deficits. Cranial irradiation (CRT) has been implicated as the major cause for cognitive dysfunction. To clarify the etiology, incidence, and severity of intellectual compromise in children with brain tumors after CRT, a prospective study was undertaken comparing the neuropsychological outcome in 18 consecutive children with malignant brain tumors treated with CRT to outcome in 14 children harboring brain tumors in similar sites in the nervous system who had not received CRT. Children with cortical or subcortical brain tumors were not eligible for study. Neuropsychological testing was performed after surgery prior to radiotherapy, after radiotherapy, and at 1- and 2-year intervals thereafter. Children who had received CRT had a mean full-scale intelligence quotient (FSIQ) of 105 at diagnosis which fell to 91 by Year 2. Similar declines were noted in their performance intelligence quotient (IQ) and verbal IQ. After CRT, patients demonstrated a statistically significant decline from baseline in FSIQ (p < 0.02) and verbal IQ (p < 0.04). Children who had not received CRT did not demonstrate a fall in any cognitive parameter over time. The decline between baseline testing and testing performed at Year 2 in patients who had CRT was inversely correlated with age (p < 0.02), as younger children demonstrated the greatest loss of intelligence. Children less than 7 years of age at diagnosis had a mean decline in FSIQ of 25 points 2 years posttreatment. No other clinical parameter correlated with the overall IQ or decline in IQ. After CRT, children demonstrated a wide range of dysfunction including deficits in fine motor, visual-motor, and visual-spatial skills and memory difficulties. After CRT, children with brain tumors also demonstrated a fall in a wide range of achievement scores and an increased need, over time, for special help in school. The 2-year results of this study suggest that children with brain tumors treated with CRT are cognitively impaired and that these deficits worsen over time. The younger the child is at the time of treatment, the greater is the likelihood and severity of damage. These children, although not retarded, have a multitude of neurocognitive deficits which detrimentally affects school performance. New treatment strategies are needed for children with malignant brain tumors.
Lumboperitoneal shunt combined with myelotomy for treatment of syringohydromyelia
Authors: Park T. S. , Cail Wayne S. , Broaddus William C. , Walker Melissa G.
Published: May 2009

✓ This study was undertaken to investigate whether a direct communication between the fourth ventricle and the syrinx exists in the majority of patients with syringohydromyelia and whether intraspinal pressure plays a role in the pathogenesis of this disorder. A series of 13 patients with syringohydromyelia delineated by magnetic resonance (MR) imaging was reviewed, and the intracranial pressure (ICP) and lumbar spinal pressure (LSP) were recorded concomitantly in three patients. Lumboperitoneal shunting was performed in seven patients, six of whom also underwent myelotomy of the caudal spinal cord. Magnetic resonance imaging visualized a cerebrospinal fluid (CSF) channel connecting the fourth ventricle with the syrinx in only one of the 13 patients, and in the remaining 12 patients it revealed a long segment of the spinal cord free of syrinx below the fourth ventricle. This finding is in accordance with recent MR studies of syringohydromyelia. The concomitant recording of ICP and LSP in our patients who had myelomeningocele and Chiari II malformation showed findings contradicting the reports of Williams. Lumbar spinal pressure was equal to ICP under steady-state conditions, and was elevated by straining or crying more markedly than ICP. Craniospinal pressure dissociation with ICP greater than with LSP, as described by Williams, was not observed. Lumboperitoneal shunting concomitant with myelotomy and syringopleural shunting 1 month after myelotomy resulted in marked and sustained shrinkage of the syrinx and neurological improvement in four patients. It was concluded that the majority of patients with syringohydromyelia and Chiari malformation lack a direct communication connecting the fourth ventricle with the syrinx. The results suggest that CSF moves under pressure into the spinal cord, contributing to the formation and maintenance of the syrinx, and that LP shunting combined with myelotomy can effect shrinkage of the syrinx.
Transcranial Doppler sonography within 12 hours after subarachnoid hemorrhages
Authors: Romner Bertil , Ljunggren Bengt , Brandt Lennart , Säveland Hans
Published: May 2009

✓ Twenty-one patients were subjected to repeated assessment of cerebral blood flow velocities by means of transcranial Doppler sonography (TCDS) during the first 12 hours after subarachnoid hemorrhage (SAH). In 19 patients the study was performed following the first SAH, and in two after early rebleeds. Flow velocities did not indicate an early phase of arterial narrowing in any case. Following the first TCDS assessment, flows were evaluated repeatedly in the 19 survivors. Increased flow velocities suggesting arterial narrowing or vasospasm occurred only after a delay of at least 4 days. The results of this study favor the restoration of normal velocity patterns in surviving patients and do not indicate that an acute phase of vasospasm exists either immediately after or in the first 12 hours after SAH.
Neurilemomas of the trigeminal nerves
Authors: Pollack Ian F. , Sekhar Laligam N. , Jannetta Peter J. , Janecka Ivo P.
Published: May 2009

✓ Sixteen patients with trigeminal neurilemoma have been treated at the University Health Center of Pittsburgh during the last 15 years. Two patients had middle fossa tumors arising from the trigeminal ganglion, four had posterior fossa tumors arising from the trigeminal roots, six had “hourglass” lesions extending above and below the tentorium and involving the trigeminal ganglion and its roots, and four had tumors arising from the trigeminal branches and extending through the superior orbital fissure, foramen rotundum, or foramen ovale. In seven patients, tumor had also invaded the cavernous sinus. The clinical and radiographic features of these tumors, the operative approaches employed, and the postoperative outcome are discussed. Complete tumor excision was achieved in 12 patients; all 12 remain free of recurrence 3 to 157 months after surgery. In contrast, all four patients who underwent subtotal tumor excision showed progressive neurological deterioration from regrowth of residual tumor within 3 years of the initial surgery. Two of these four subsequently had total tumor excision and both are disease-free 23 and 34 months after the second procedure. Major morbidity developed in only one of the 16 patients. There were no operative deaths. Nine patients had preserved or improved trigeminal function after treatment.
The treatment of spontaneous intracerebral hemorrhage
Authors: Juvela Seppo , Heiskanen Olli , Poranen Antti , Valtonen Simo , Kuurne Timo , Kaste Markku , Troupp Henry
Published: May 2009

✓ In a prospective study, 52 patients with a spontaneous supratentorial intracerebral hematoma (ICH) were randomly assigned to receive emergency surgery or conservative treatment within 48 hours after the bleed. Patients with a decreased level of consciousness and/or a severe neurological deficit were admitted to the study. The overall mortality rate at 6 months was 42%: 10 (38%) of the 26 patients in the conservative group and 12 (46%) of the 26 in the surgical group. Six (20%) of the 30 survivors at 6 months were able to conduct their activities of daily living independently: five (31%) of the 16 patients in the conservative group and one (7%) of the 14 in the operative group. These differences are not statistically significant. The mortality rate of semicomatose or stuporous patients (Glasgow Coma Scale score 7 to 10) was statistically significantly lower in the surgical group (none of the four patients) than in the conservative group (four of five patients) (p < 0.05); however, all surviving patients in this subgroup were severely disabled. The study suggests that surgical treatment of this category of patients with ICH does not offer any definite advantage over conservative treatment. In semicomatose or stuporous patients, surgery may improve the length of survival, but the quality of life remains poor.
The effect of hypothermia on regional spinal cord blood flow in rats
Authors: Sakamoto Toshihisa , Monafo William W.
Published: May 2009

✓ Spinal cord ischemia may accompany surgical procedures on the aorta or vertebral column. Regional spinal cord blood flow (SCBF) was measured at five vertebral levels in the spinal cords of pentobarbital-anesthetized rats based on the distribution of intravenously injected carbon-14-labeled butanol. In seven normal rats, mean SCBF (± standard error of the mean) ranged from 52.7 ± 5.4 to 68.5 ± 4.9 ml ⋅ min−1 ⋅ 100 gm−1 (depending on the level, being lowest at the thoracic levels) and mean arterial blood pressure (MABP) was 126 mm Hg. Corporal hypothermia (mean rectal temperature 28.1° ± 0.6°C) was induced by cold exposure in seven other rats, and SCBF, measured immediately thereafter, was significantly elevated at all five levels by 52% to 69% compared to the normal group. However, MABP was elevated in the hypothermic group to 165 ± 4 mm Hg (p < 0.0001). Therefore, in seven additional hypothermic rats, MABP was maintained at the control level by withdrawal of arterial blood as necessary. In these animals, SCBF at all levels was still significantly elevated compared with the normal group and the values were nearly identical to those measured in the hypertensive hypothermic rats. It was concluded that hemodynamic autoregulation of SCBF is impaired in the presence of moderate systemic hypothermia in pentobarbital-anesthetized rats.
The effect of furosemide on intracranial pressure and hemorrhage in preterm rabbits
Authors: Lorenzo Antonio V. , Greene Clarence S. , Hornig Gregory W. , Zavala L. Manuel , Welch Keasley
Published: May 2009

✓ The hypothesis that intracranial hypotension due to excessive postnatal fluid loss places the premature infant at risk for germinal matrix and intraventricular hemorrhage (GM-IVH) was tested in preterm rabbits delivered at 28 and 29 days of gestation (term 32 days). Furosemide administered to newborn pups induced a diuresis that resulted in a 11% to 22% loss in body weight and a concomitant decline in muscle water (13% to 16%) and sodium (18% to 21%). Paradoxically, no change occurred in the water or electrolyte content of the brain even though cerebrospinal fluid and brain tissue pressure, but not blood pressure, declined. These changes were absent in littermates treated with saline. Microscopic examination of brain sections revealed a greater incidence of intracranial hemorrhage, particularly in the germinal matrix and choroid plexus, in furosemide-treated than in saline-treated preterm rabbit pups. These results are consistent with the hypothesis that intracranial hypotension promotes the incidence of GH-IVH in preterm animals.
The effect of atherosclerosis on endothelium-dependent relaxation in the aorta and intracranial arteries of rabbits
Authors: Kanamaru Kenji , Waga Shiro , Tochio Hiroshi , Nagatani Kazuhiko
Published: May 2009

✓ The effect of hypercholesterolemia on vascular responsiveness was studied in isolated rabbit arteries. The arteries of animals maintained on a cholesterol-rich (1%) diet for 6 months had more pronounced intimal lesion than those receiving the diet for 3 months. The aortas were more severely damaged than the carotid or basilar arteries. Segments of the arteries were mounted in organ chambers for isometric tension recording or for measurement of the endothelium-derived relaxing factor. Endothelium-independent relaxation induced by glyceryl trinitrate was not affected even in the most severely damaged arteries; endothelium-dependent relaxation in response to acetylcholine (ACh) and A23187 was progressively inhibited as the degree of fatty streak formation increased. In the carotid arteries, mean (± standard deviation) relaxation induced by 10−5 M of ACh (expressed as a percentage of the maximum relaxation induced by 10−4 M of papaverine) decreased from 87.33% ± 6.30% in control tissues to 60.90% ± 4.64% in vessels from animals subjected to 6 months of hypercholesterolemia (p < 0.01); in the aortas, mean relaxation due to 10−5 M of ACh was 85.08% ± 8.03% in control tissues and 41.35% ± 13.68% in hypercholesterolemic tissues (p < 0.01). In the carotid arteries, mean relaxation induced by 10−7 M of A23187 decreased from 95.81% ± 3.58% in control tissues to 55.95% ± 2.81% in hypercholesterolemic tissues (p < 0.01); in the aortas, relaxation in response to 10−7 M of A23187 was 73.73% ± 4.35% in control tissues and 29.35% ± 6.77% in hypercholesterolemic tissues (p < 0.01). Intimal lesions were not produced in the basilar arteries even in rabbits with 12 months of hypercholesterolemia, and endothelium-dependent relaxation was preserved.
Surgical treatment of progressive visual loss in traumatic optic neuropathy
Authors: Guy John , Sherwood Mark , Day Arthur L.
Published: May 2009

✓ In two patients with traumatic optic neuropathy progressive visual loss was reversed by surgical decompression of the optic nerve sheath. The first patient with hemorrhage beneath the optic nerve sheath had progressive loss of vision from counting fingers to no light perception within 24 hours after the injury. Surgical evacuation of the hematoma improved visual acuity to 8/30. The second patient had progressive visual loss from 20/20 to 20/400 within the 1st week after injury. Drainage of an arachnoid cyst of the optic nerve sheath improved visual acuity to 20/25. Computerized axial tomography disclosed the hemorrhage in the first case and enlargement of the optic nerve sheath in the second. While the management of traumatic optic neuropathy is controversial, surgical intervention for an arachnoid cyst and hematoma involving the optic nerve is clearly beneficial.
Etiology of intracranial berry aneurysms
Authors: Stehbens William E.
Published: May 2009

✓ The congenital theory of the etiology of intracranial berry aneurysms has been widely accepted for manyyears. Review of the supporting evidence indicates that it is not based on sound scientific data but on unscientific and unsubstantiated allegations. There is no evidence of a congenital, developmental, or inherited weakness of the vessel wall. The most plausible explanation is that the aneurysms are acquired degenerative lesions — the effect of hemodynamic stress. The mural atrophy leading to aneurysmal dilatation is an acquired lesion which can be produced experimentally by hemodynamics alone. Hypertension and connective tissue disorders associated with acquired loss of tensile strength of the connective tissues are not essential: they appear to be aggravating rather than causal factors. Occlusion of one or more feeding vessels may enhance the possibility of aneurysm formation at large arterial forks subjected to the augmented hemodynamic stress associated with collateral flow.
Management of spinal dural arteriovenous malformations
Authors: Morgan Michael K. , Marsh W. Richard
Published: May 2009

✓ Dura-based spinal arteriovenous malformations (AVM's) are being diagnosed with increasing frequency. The optimal management of such lesions remains a topic of discussion. In an effort to guide this discussion, the authors review their experience with 17 cases of spinal dural AVM treated between January, 1984, and July, 1987. All patients presented with a slowly progressive paraparesis. The abnormalities were initially identified on myelography and confirmed by selective spinal angiography. Fourteen patients underwent endovascular embolization as a primary treatment, and a total of 18 embolization procedures were performed. After all but two of these, obliteration was confirmed at angiography. Patients' symptoms improved following 15 or these procedures but early improvement was not sustained in 10 instances; patients were unchanged after two procedures and worse after one. Follow-up angiography was performed at varying intervals after 15 of the 18 procedures, and recanalization of the previously obliterated spinal dural AVM was demonstrated in 13 instances. Eight patients ultimately underwent surgical treatment of their dura-based spinal AVM. No patient suffered deterioration of symptoms following operation. While embolization may allow angiographic obliteration of a spinal dural AVM and early clinical improvement, for the majority of patients these are not sustained. The average time to treatment failure was 5 months. Newer embolization materials will be necessary to effect permanent treatment in many of these patients.
Outcome following aneurysm wrapping: a 10-year follow-up review of clipped and wrapped aneurysms
Authors: Todd Nicholas V. , Tocher Janis L. , Jones Pat A. , Miller J. Douglas
Published: May 2009

✓ One hundred and eighty-one patients with single aneurysms involving the anterior circulation were treated either by wrapping (60 cases) or clipping (121 cases), and 96.1% of them were followed for 10 years. The rate of early rebleeding (< 6 months) from wrapped aneurysms was 8.6% (confidence interval 1.4% to 15.8%) and the late rebleeding (6 months to 10 years) rate was 1.5% per annum (confidence interval 0.3% to 2.5%/yr). Wrapping an aneurysm offers some protection from rebleeding, particularly during the first 6 months when the risk of rebleeding is high.
Percutaneous trigeminal ganglion compression for trigeminal neuralgia
Authors: Brown Jeffrey A. , Preul Mark C.
Published: May 2009

✓ Between 1983 and 1988, a percutaneous trigeminal ganglion compression (PTGC) procedure for trigeminal neuralgia was performed on 22 patients. All patients were initially relieved of their pain. There were three recurrences (14%); two of these patients underwent a second PTGC procedure and one a partial trigeminal nerve root section. Follow-up examination 3 to 53 months after the procedure showed that all patients were free of pain. Morbidity included persistent minor hypesthesia in five patients, persistent minor dysesthesias in three, persistent minor weakness in three, aseptic meningitis in one, transient sixth nerve palsy in one, and transient otalgia in three. None of the patients had either anesthesia dolorosa or an absent corneal reflex.
Ultrastructure of the orbital pathway for cerebrospinal fluid drainage in rabbits
Authors: Erlich Stephanie S. , McComb J. Gordon , Hyman Shigeyo , Weiss Martin H.
Published: May 2009

✓ An increasing number of physiological and morphological studies indicate that cerebrospinal fluid (CSF) drains via nonarachnoidal pathways in several mammalian species. Ultrastructural tracer studies were undertaken to examine the orbital route for CSF absorption in the rabbit. At the termination of the optic nerve subarachnoid space, an area of connective tissue containing numerous small tortuous channels is present. Ferritin (molecular weight 400,000) infused into the ventricles at normal and increased intraventricular pressure was present in these channels by 15 minutes postinfusion, and subsequently reached the intraorbital connective tissue. Elevating the intraventricular pressure did not noticeably alter the morphological appearance of this region or change the gross distribution pattern of the ferritin. Ferritin did not penetrate the scleral barrier to reach the choriocapillaris, nor did it breach the arachnoid barrier layer proximal to the transitional zone at the optic subarachnoid space to reach the dura mater. These results are very similar to those described for the hamster orbital region and the rabbit cribriform region. These experiments support the concept that macromolecules exit the subarachnoid space at the termination of the optic nerve via open channels, and that no significant barrier to drainage of macromolecules in CSF is present at this location.
Effect of blood transfusion, dopamine, or normal saline on neurogenic shock secondary to acutely raised intracranial pressure
Authors: Rahimifar Majid , Tator Charles H. , Shanlin Ruby J. , Sole Michael J.
Published: May 2009

✓ An experimental model to simulate acutely raised intracranial pressure due to a rapidly expanding intracranial space-occupying lesion was used to produce neurogenic shock. Forty-one rats in neurogenic shock (defined as a mean systemic arterial pressure (SAP) of less than 60 mm Hg) were subjected to various treatments to increase the mean SAP to a level of more than 80 mm Hg. The control group with neurogenic shock received no treatment, and the six treatment groups received infusions of: whole blood, packed cells, plasma, normal saline, dopamine, or a combination of dopamine and saline. Detrimental effects were observed after transfusion of packed cells or whole blood, which caused further deterioration of mean SAP. Although dopamine or the combination of dopamine and saline were both effective (p = 0.0001) for reversing hypotension, the combination was the most effective. If this rat paradigm correlates with human disease, these results indicate that, in the absence of hypovolemia, neurogenic shock due to acute intracranial hypertension should be treated with a combined transfusion of dopamine and normal saline, but not blood since the latter could have a detrimental effect.
Angiogenic activity of the atherosclerotic carotid artery plaque
Authors: Alpern-Elran Hanoch , Morog Nicholas , Robert Françoise , Hoover Gayle , Kalant Norman , Brem Steven
Published: May 2009

✓ Neovascularization is observed in complicated atherosclerotic plaques associated with cellular proliferation, plaque hemorrhage, and thrombosis. The angiogenic activity of 278 plaque fragments was tested; the fragments were taken from 12 patients with cerebral ischemia who underwent carotid endarterectomy. Angiogenesis, determined by the sustained ingrowth of new vessels in the rabbit cornea, was induced in 125 (45%) of these fragments. By contrast, angiogenesis was found in only two (2.4%) of 80 control tissues (p < 0.001): in none of 22 samples of boiled atherosclerotic plaque; in two of 26 samples of normal rabbit carotid artery; and in none of 32 samples of nonatherosclerotic human uterine artery. Histological evaluation revealed that the cellular zones (composed mainly of smooth-muscle cells) were highly angiogenic, with 97 (76%) of 127 samples showing angiogenesis compared with 23 (17%) of 132 acellular fragments that consisted of amorphic, necrotic, calcific, lipid-laden material (p < 0.001).

These results indicate that angiogenesis in vivo is a function of the cellular component of the advanced atherosclerotic plaque, and is not expressed in the normal, stable arterial wall. The fragile new vessels could promote the growth of the plaque or be a source of hemorrhages, microinfarcts, and plaque fissures that convert a stable, silent lesion to an expanding, ulcerated, thrombotic, symptomatic plaque.
Intramedullary spinal Histoplasma granuloma
Authors: Voelker Joseph L. , Muller Jans , Worth Robert M.
Published: May 2009

✓ While there have been several cases of cerebral histoplasmoma published in the literature, the occurrence of such a lesion in an intramedullary spinal location has not previously been reported. The authors present a patient with a Brown-Séquard lesion secondary to an intramedullary Histoplasma granuloma in the cervical region. The case was successfully managed with surgical removal of the lesion.
Construction of a simple multi-lead electrode for intraoperative nerve recording
Authors: Ashley Robert A. , Wee Abelardo S.
Published: May 2009

✓ In the operating room, a fast and accurate means of recording nerve action potentials (NAP's) is always desirable. The multi-lead recording electrode described in this paper contains these desirable features. It can survey and obtain a number of NAP's from different nerve segments at the same time and under the same recording condition. The fixed distances between the recording leads enable quick calculation of conduction velocities of different nerve segments. Construction of the electrode is simple, and it can be designed to suit individual needs. The cost is marginal, reflecting primarily the costs of the original subdermal needle electrodes. The device is both safe and disposable.
The transoral approach to the superior cervical spine
Authors: Hadley Mark N. , Spetzler Robert F. , Sonntag Volker K. H.
Published: May 2009

✓ The transoral-transclival surgical approach is the most direct operative approach to pathology ventral to the brain stem and superior spinal cord. In selected patients, this approach is efficacious in the treatment of extradural compressive lesions from the cervicomedullary junction to the C-4 vertebra.

The authors have used the transoral surgical approach in treating 53 patients with lesions compressing the ventral extradural brain stem or the cervical cord. The evaluation, management, and long-term outcome of these patients are described (median follow-up time 24 months). The operative morbidity rate in this series was 6%, and the operative mortality rate was zero. The authors review specific features of the transoral procedure, including methods of retraction, microsurgical techniques, and adjunctive measures to avoid cerebrospinal fluid fistulae, that contributed to these good results.
Use of computerized electroencephalographic monitoring during aneurysm surgery
Authors: Tempelhoff Rene , Modica Paul A. , Rich Keith M. , Grubb Robert L.
Published: May 2009

✓ The clinical usefulness of intraoperative electroencephalographic (EEG) monitoring of cerebral perfusion during aneurysm surgery has received little attention, primarily due to problems with electrode placement over the operative site, which is the area of maximal risk. In this report, 27 patients undergoing surgery for anterior circulation aneurysms were monitored intraoperatively with a two-channel computerized EEG complex using a bilateral frontal-occipital montage. In 16 patients, a normal EEG pattern was observed throughout surgery; all 16 awoke neurologically intact and their postoperative angiograms did not reveal cerebral vasospasm. In the other 11 patients, one of two patterns of persistent EEG abnormalities was identified. 1) In six of these patients a marked attenuation of EEG activity was observed ipsilaterally which coincided with various intraoperative events including brain retraction, hypotension, and aneurysm dissection/clipping. Five of these six patients awoke with new neurological deficits which persisted beyond 12 hours in two, both of whom had angiographically proven vasospasm 24 hours after surgery. 2) In the remaining five patients, a distinct abnormal EEG pattern consisting of marked hyperactivity in the delta, theta, and alpha frequency ranges was observed ipsilaterally. Four of these five patients had a poor neurological outcome and vasospasm on their angiogram 24 hours after surgery. Thus, EEG monitoring which spans the operative area during aneurysm surgery is practicable and appears to be of value in the detection of compromised cerebral perfusion during aneurysm surgery. The possible significance of the two abnormal EEG patterns identified in this report is discussed.
The effect of subarachnoid hemorrhage on blood and CSF atrial natriuretic factor
Authors: Rosenfeld Jeffrey V. , Barnett Gene H. , Sila Cathy A. , Little John R. , Bravo Emmanuel L. , Beck Gerald J.
Published: May 2009

✓ Atrial natriuretic factor (ANF) is a diuretic natriuretic peptide hormone produced by both the heart and brain which has been postulated to play a role in the hemodynamic and sodium instability that frequently follows subarachnoid hemorrhage (SAH). Levels of ANF were measured in 12 patients with nontraumatic SAH and nine control patients with unruptured cerebral aneurysms. At surgery, the mean plasma ANF level (± standard deviation) of the SAH group was significantly higher than that of the control group (158.1 ± 83.8 vs. 57.8 ± 45.3 pg/ml, respectively; p = 0.01). There was no significant difference in serum sodium concentration, blood pressure, or central venous pressure between these groups. Nine patients with SAH due to aneurysm rupture had plasma ANF levels similar to those in three patients with SAH due to other causes. Four patients with moderate to severe SAH had significantly higher mean cerebrospinal fluid (CSF) ANF values (17.7 ± 12.8 pg/ml) than five patients with minimal SAH (0.6 ± 0.9 pg/ml) or the control group of nine patients (3.7 ± 1.3 pg/ml) (p < 0.05). Five patients with moderate to severe SAH had significantly higher plasma ANF values (202.6 ± 72.2 pg/ml) than five with minimal SAH (86.8 ± 29.2 pg/ml) or the control group (57.8 ± 45.3 pg/ml) (p < 0.05). Plasma ANF values were substantially higher than CSF ANF content in the SAH group (p < 0.01) and in the control group (p = 0.05).

From these data it is concluded that: 1) plasma ANF is elevated significantly after SAH; 2) this rise appears unrelated to the cause of hemorrhage, serum sodium concentration, blood pressure, or central venous pressure, but is related to the extent of the hemorrhage; 3) ANF concentrations in the CSF are significantly lower than in plasma, and are elevated after moderate to severe SAH; and 4) the source of CSF ANF is probably the plasma, and the source of plasma ANF is likely the heart.
An immunohistochemical study of neuroepithelial (colloid) cysts
Authors: Kondziolka Douglas , Bilbao Juan M.
Published: May 2009

✓ Monoclonal and polyclonal antisera were used against 12 cases of neuroepithelial (colloid) cysts to determine the specific antigenic profile of the cyst epithelium. Intermediate filament markers (cytokeratin, vimentin, neurofilament, and glial fibrillary acidic protein) and epithelial markers (epithelial membrane antigen and monoclonal antibody lu-5) demonstrated that colloid cyst epithelium has a unique antigenic profile in contrast to that of choroid plexus or glial tissue. Theories raised to explain the etiology of colloid cysts have included derivation from the embryonic paraphysis, detachments of developing neuroepithelium from the tela choroidea, and remnants of respiratory epithelium; a more recent theory suggests that these cysts are products of developing choroid plexus or ependyma. The present study shows that colloid cyst epithelium is distinct from that of choroid plexus or ependyma and therefore does not represent a product of their formation, nor does it represent a form of immature glia. This finding supports the conclusion that colloid cysts in any ventricular location represent a developmental anomaly of primitive neuroectoderm in the embryo, which remains unique from other products of neuroectodermal derivation.
Effect of the 21-aminosteroid U-74006F on cerebral vasospasm following subarachnoid hemorrhage
Authors: Zuccarello Mario , Marsch Jeffery T. , Schmitt Gerald , Woodward James , Anderson Douglas K.
Published: May 2009

✓ The purpose of this study was to use a new 21-aminosteroid (U-74006F) with in vitro antioxidant and antilipolytic properties as a pharmacological probe to assess the role of lipid hydrolysis and peroxidation in a rabbit model of subarachnoid hemorrhage (SAH)-induced vasospasm. Cerebral angiograms were performed on 15 rabbits. Eighteen hours later, 1 cc/kg of autologous blood was infused into the cisterna magna of all 15 animals. Six rabbits received no treatment, six received U-74006F starting 30 minutes after SAH, and three rabbits received the vehicle for U-74006F starting 30 minutes after SAH. At 72 hours post-SAH, a second angiogram was obtained. Digital subtraction angiographic techniques were used to measure the diameter of and contrast material flow through the basilar artery. At 72 hours post-SAH, vasospasm was evident in all untreated and vehicle-treated rabbits. The diameter of and the flow through the basilar artery were significantly reduced 42.3% ± 6.6% and 46.8% ± 5.8%, respectively, below pre-SAH levels (means ± standard error of the means). Treatment with U-74006F eliminated the SAH-induced vasospasm; in treated animals, both the flow through and the diameter of the basilar arteries were at pre-SAH levels. These findings indicate that: 1) membrane lipid changes (that is, hydrolysis with eicosanoid production and/or peroxidation) contribute to the chronic vasospasm resulting from SAH, and 2) U-74006F prevents the SAH-induced chronic vasospasm in this model by limiting these pathological membrane events.
Vicryl (polyglactin 910) mesh as a dural substitute in the presence of pia arachnoid injury
Authors: Nussbaum Charles E. , Maurer Paul K. , McDonald Joseph V.
Published: May 2009

✓ Previously presented data showed that Vicryl mesh was a potentially effective dural grafting material. It is easily handled, relatively inexpensive, absorbed over time, and elicits a minimal inflammatory response. The present experimental project was conducted to investigate the effectiveness of a tightly woven version of the material as a watertight seal and to evaluate its performance in the presence of pia arachnoid injury. The mesh formed a seal promptly and adhesion formation was slight. Tightly woven Vicryl mesh appears to have a significant potential as an absorbable dural substitute.
Venous rupture during transvenous approach to a carotid-cavernous fistula
Authors: King Wesley A. , Hieshima Grant B. , Martin Neil A.
Published: May 2009

✓ An attempt at transfemoral transarterial balloon occlusion of a high-flow spontaneous carotid-cavernous fistula was unsuccessful because the carotid artery rent was too small for this approach. During a subsequent transvenous approach to the cavernous sinus through the jugular vein, the inferior petrosal sinus was perforated. A minor subarachnoid hemorrhage occurred before the tear could be sealed by the deposition of three Gianturco coils in the vein. The patient was taken to the operating room for emergency obliteration of the fistula and petrosal sinus in order to remove the risk of further hemorrhage. Under the guidance of intraoperative digital subtraction angiography, isobutyl-2-cyanoacrylate was injected directly into the surgically exposed cavernous sinus. Successful obliteration of the fistula was achieved with preservation of the carotid artery, and the angiography catheter was removed safely from the petrosal sinus. Although initially after surgery the patient had nearly complete ophthalmoplegia, at her 1-year follow-up examination she had normal ocular motility and visual acuity. The transvenous approach to the cavernous sinus and alternative methods of treatment of carotid-cavernous fistulas are discussed.
Pituitary gland metastasis from adenocarcinoma of the prostate
Authors: Couldwell William T. , Chandrasoma Parakrama T. , Weiss Martin H.
Published: May 2009

✓ A case of prostatic carcinoma metastasis to the pituitary gland is reported. The presentation and rarity of such a lesion is addressed. The literature review yielded only isolated case reports of symptomatic brain metastases unassociated with bone disease from adenocarcinoma of the prostate. The management options of such a lesion are discussed.
A temporal approach to anterior communicating artery aneurysms
Authors: Poletti Charles E.
Published: May 2009

✓ As an alternative to approaching anterior communicating artery (ACoA) aneurysms through the frontal fossa, either parasagittally or laterally (pterional, gyrus rectus approach), this report describes an approach to ACoA aneurysms through the temporal fossa. The main advantages of this temporal technique are that it requires less brain retraction, gives better surgical orientation, gains control of both A1 segments before disturbing the aneurysm, and involves minimal resection of brain tissue. This temporal approach has recently been used by the author in 20 consecutive operations for ACoA aneurysms in preference to the gyrus rectus approach.