bluuebunny/crossref_metadata_2025 huggingface dataset:
Symptomatic Chiari malformations
Authors: Dyste Gregg N. , Menezes Arnold H. , VanGilder John C.
Published: May 2009

✓ The Chiari malformation is a condition characterized by herniation of the posterior fossa contents below the level of the foramen magnum, and is categorized into three types based on the degree of herniation. The authors review their surgical experience between 1975 and 1985 with 50 patients afflicted with symptomatic Chiari malformations. Any patient with associated myelomeningocele, tethered spinal cord, lipoma, or diastematomyelia was excluded from this series. Forty-one patients had Chiari I malformations, seven were classified as having Chiari II, and two as having Chiari III. The presentation of pediatric and adult patients was identical. Treatment was directed at the posterior fossa pathology. Seven patients with accompanying ventral bone compression underwent transoral decompression of the cervicomedullary junction, 42 had posterior decompressive procedures, and six received ventriculoperitoneal shunts. The posterior decompression included opening the outlet foramina of the fourth ventricle, occluding any communication between the spinal cord central canal and the obex, shunting the fourth ventricle, and placing a dural graft. Postoperatively, 20% of the patients are asymptomatic, 66% improved, and 8% stabilized; in 6% the disease has progressed in spite of multiple procedures. Preoperative signs that are predictive of a less favorable outcome include muscle atrophy, symptoms lasting longer than 24 months, ataxia, nystagmus, trigeminal hypesthesia, and dorsal column dysfunction (p < 0.05, chi-square test). A model based on the presence or absence of atrophy, ataxia, and scoliosis at the time of the preoperative examination has been generated that allows prediction of long-term outcome at the 95% confidence level.
The effect of intravenous interleukin-2 on brain water content
Authors: Saris Stephen C. , Patronas Nicholas J. , Rosenberg Steven A. , Alexander Joseph T. , Frank Joseph , Schwartzentruber Douglas J. , Rubin Joshua T. , Barba David , Oldfield Edward H.
Published: May 2009

✓ Parenteral treatment with interleukin-2 (IL-2) is effective against certain advanced cancers outside the central nervous system. Prior to commencement of Phase II trials in patients with brain tumors, the neurological and neuroradiological features of 10 patients treated with intravenous administration of repeated doses of IL-2 were studied. Three patients had malignant gliomas, and seven patients had extracranial cancer without evidence of intracranial metastasis. All were treated with intravenous doses of 105 U/kg three times daily for up to 5 days. The patients with gliomas received cranial computerized axial tomography (CT) scans before IL-2 therapy was initiated and during the later stages of treatment. The patients with extracranial cancer under-went T2-weighted magnetic resonance (MR) imaging before and later during therapy.

After two to 11 doses of IL-2, the patients with gliomas had marked neurological deterioration that was associated with a mild to marked increase in peritumoral edema and mass effect visible on CT scans. With cessation of treatment and appropriate supportive care, all returned to their pretreatment state. The patients with extracranial cancer were either neurologically unchanged or underwent minor transient changes in mental status (lethargy and confusion). In these patients, the MR signal intensity was quantified and compared in eight anatomic regions of interest. In six of the seven patients, there were increases in gray and white matter signal intensity consistent with increased cerebral water content. The percentage changes (means ± standard error of the means) were 12.6% ± 7.3% in the gray matter and 17.0% ± 6.2% in the white matter.

This study demonstrates that treatment with a high parenteral dose of IL-2 is not tolerated by patients with gliomas due to increased cerebral edema. In patients with extracranial cancer but no brain disease, parenteral IL-2 induces an increase in the cerebral water content of both gray and white matter.
Cranial burr hole for revascularization in moyamoya disease
Authors: Endo Masataka , Kawano Nobuyuki , Miyasaka Yoshio , Yada Kenzoh
Published: May 2009

✓ Currently, superficial temporal artery-middle cerebral artery (MCA) anastomosis, encephalomyosynangiosis (EMS), and encephalo-duro-arterio-synangiosis are used to treat moyamoya disease and are reported to effectively improve ischemic symptoms. All are methods of reversing the flow of blood from the external carotid artery system into the cortical branches of the MCA. As moyamoya disease advances, these operations alone will predictably not correct the deterioration in blood flow in the territory of the anterior cerebral artery. It was noted in a case of moyamoya disease with intraventricular hemorrhage that a burr hole, made in the frontal region for drainage purposes, induced marked neovascularization. Since then, similar frontal burr holes have been made in five juvenile cases of moyamoya disease; this procedure involved making a burr hole in both frontal bones and incising both the dura and the arachnoid membrane. In two cases a frontal burr hole was placed simultaneously with EMS, and in the others the frontal burr hole was made following EMS. The clinical symptoms improved after the frontal burr hole was made, and dynamic computerized tomography revealed improved circulation in the frontal regions. Together with conventional surgical therapy for juvenile cases of moyamoya disease, this operation is considered beneficial both to the circulation in the frontal region and for the protection of frontal brain function.
Management of depressed skull fractures
Authors: van den Heever C. Mauritz , van der Merwe David J.
Published: May 2009

✓ The management of 319 cases with nonmissile depressed skull fractures is discussed. The majority of these injuries (75%) resulted from assaults and more than 90% were compound fractures. Of these, 35 cases were excluded from the series; these were patients who died before investigation or treatment could be instituted, or whose major injury was an intracranial hematoma or extensive traumatic hemorrhagic necrosis rather than a depressed fracture with underlying localized contusion. In the remaining 284 cases a comparison is made between the outcome in 124 (44%) patients treated by a conventional surgical method and 160 (56%) selected patients whose wound was only inspected, cleaned, and sutured in the emergency room. The nonsurgical group included 21 (9%) patients with simple depressed fractures and also patients without severe wound contamination, established infection, severe comminution of the fracture, or brain or cerebrospinal fluid in the wound. The results of management were assessed in relation to septic complications, the outcome of focal neurological abnormalities, and fatal complications. The group treated conservatively compared favorably with the surgical cases and also with previously reported series. The obvious bias in favor of the conservative group is admitted; however, it is clear that the majority of simple fractures and some compound depressed skull fractures can be managed safely without major surgical intervention. Socioeconomic implications are discussed.
The apnea test for the determination of brain death
Authors: Benzel Edward C. , Gross Charles D. , Hadden Theresa A. , Kesterson Lee , Landreneau Michael D.
Published: May 2009

✓ By conventional criteria, an apneic patient's PaCO2 must be greater than 60 mm Hg before apnea can be attributed to brain death. The rate of a PaCO2 increase in the apneic patient traditionally has been thought to be in the range of 3 mm Hg/min. In order to assess the validity of these data and the validity of the “apnea test” for determination of brain death, the results of this test were reviewed in 20 patients. In all patients, arterial blood samples were drawn for blood gas measurements every 2 minutes following the cessation of volume ventilation (with an oxygen cannula at 6 liters O2/min passed into the tracheobronchial tree).

The rate of PaCO2 increase was noted to be very erratic. The average rate of rise was 3.7 ± 2.3 mm Hg/min (± standard deviation). This, however, varied from 0.5 to 10.5 mm Hg/min and was not predictable from the variables evaluated. The rate of PaCO2 increase was noted to decline throughout the duration of the test. This ranged from 3.9 ± 1.2 mm Hg/min (for patients with baseline PaCO2 ≤ 30 mm Hg) and 4.5 ± 1.9 mm Hg/min (for patients with baseline PaCO2 ≥ 30 mm Hg) in the first 4 minutes of the test to an average of 0.92 mm Hg/min for patients with test lasted longer than 12 minutes. These unpredictable results might be related to CO2 washout, atelectasis, cardiac ventilations, or other yet-undefined parameters.

The nonlinear relationship between rate of PaCO2 increase and time following onset of apnea resulted in the test being prolonged in several patients. In these patients, the PaCO2 approached 60 mm Hg in an asymptotic fashion. These lengthy tests could have been avoided by utilizing a standardized apnea test with a baseline PaCO2 of 40 mm Hg or greater.

The observation that a high baseline PaCO2 greatly augments the efficiency and safety of the test allows criteria that have previously been based on conjecture to be documented and applied clinically. A standardized apnea test, utilizing these principles, may satisfy many of the criticisms regarding brain-death testing that have been raised by neurologists, neurosurgeons, and transplant surgeons.
Transcranial Doppler study of intracranial circulatory arrest
Authors: Hassler Werner , Steinmetz Helmuth , Pirschel Jürgen
Published: May 2009

✓ To investigate the hemodynamics of intracranial circulatory arrest, the authors correlated the findings of noninvasive transcranial Doppler ultrasonography (TCD) with those of transfemoral four-vessel angiography in 65 patients following brain death and intracranial circulatory arrest due to severe intracranial hypertension. The three TCD stages of intracranial circulatory arrest, which have been described previously, corresponded with different levels of extracerebral angiographic cessation of flow. With TCD progression from the first stage (oscillating flow) to the third stage (no flow), the level where the dye stopped descended caudad from subarachnoid to cervical levels. The study shows that, in progressing intracranial hypertension, arterial circulatory standstill within the cranial cavity develops in a distal-to-proximal direction. The basal cerebral arteries remain patent in the early stages of intracranial circulatory arrest. Experimental evidence from the literature, together with the findings of the present investigation, points to the capillary bed as the initial site of the flow obstruction in progressing intracranial hypertension.
Inhibition of lymphocyte function by glioblastoma-derived transforming growth factor β2
Authors: Kuppner Maria C. , Hamou Marie-France , Sawamura Yutaka , Bodmer Stefan , de Tribolet Nicolas
Published: May 2009

✓ Human glioblastoma cells secrete an inhibitory factor termed “glioblastoma-derived T-cell suppressor factor” (G-TsF). A member of the transforming growth factor beta (TGFβ) family, G-TsF is identical to TGFβ2. The present study investigated the effect of G-TsF/TGFβ2 on the proliferative and cytotoxic properties of tumor-infiltrating lymphocytes (TIL's) isolated from malignant gliomas after expansion in vitro with interleukin-2 (IL-2). The results demonstrate that the IL-2 (5 to 20 U/ml)-dependent proliferative response of glioma-derived TIL's was inhibited 70% to 85% by G-TsF/TGFβ2 and that the inhibitory effect could be reduced by using increasing concentrations of IL-2 (100 to 200 U/ml). Tumor necrosis factor alpha (TNFα) enhanced the IL-2-dependent proliferation of TIL's cultured in low concentrations of IL-2 (10 U/ml); however, neither TNFα nor interferon gamma was able to reduce the inhibitory effect of TGFβ2 on TIL proliferation. In addition, TGFβ2 suppressed 60% to 100% the cytotoxic response of glioma-derived TIL's against several tumor targets, including autologous glioma cells, and the suppressive effect was shown to be reduced by increasing concentrations of IL-2.
Axonal injury in the optic nerve: a model simulating diffuse axonal injury in the brain
Authors: Gennarelli T. A. , Thibault L. E. , Tipperman R. , Tomei G. , Sergot R. , Brown M. , Maxwell W. L. , Graham D. I. , Adams J. H. , Irvine A. , Gennarelli L. M. , Duhaime A. C. , Boock R. , Greenberg J.
Published: May 2009

✓ A new model of traumatic axonal injury has been developed by causing a single, rapid, controlled elongation (tensile strain) in the optic nerve of the albino guinea pig. Electron microscopy demonstrates axonal swelling, axolemmal blebs, and accumulation of organelles identical to those seen in human and experimental brain injury. Quantitative morphometric studies confirm that 17% of the optic nerve axons are injured without vascular disruption, and horseradish peroxidase (HRP) studies confirm alterations in rapid axoplasmic transport at the sites of injury. Since 95% to 98% of the optic nerve fibers are crossed, studies of the cell bodies and terminal fields of injured axons can be performed in this model. Glucose utilization was increased in the retina following injury, confirming electron microscopic changes of central chromatolysis in the ganglion cells and increased metabolic activity in reaction to axonal injury. Decreased activity at the superior colliculus was demonstrated by delayed HRP arrival after injury. The model is unique because it produces axonal damage that is morphologically identical to that seen in human brain injury and does so by delivering tissue strains of the same type and magnitude that cause axonal damage in the human. The model offers the possibility of improving the understanding of traumatic damage of central nervous system (CNS) axons because it creates reproducible axonal injury in a well-defined anatomical system that obviates many of the difficulties associated with studying the complex morphology of the brain.
Regeneration in the rat optic nerve after cold injury
Authors: Murakami Mineko , Ide Chizuka , Kanaya Haruyuki
Published: May 2009

✓ In order to examine nerve regeneration under conditions in which the basal laminae of the glial limiting membranes (GLM) and blood vessels were preserved intact, the intraorbital segment of adult rat optic nerve was frozen locally. During the next 3 months, degenerative and regenerative changes in axons and glial cells were observed by light and electron microscopy. On the day after treatment, all the myelinated and unmyelinated axons in the central zone of the lesion were damaged. The astrocyte endfeet of the GLM as well as the blood vessels were extensively disrupted, while their basal laminae were preserved apparently intact as a continuous sheet. Three days after treatment, regenerating axons appeared in the central zone of the lesion. They contained various numbers of clear and dense-cored vesicles as well as some smooth endoplasmic reticulum. The regenerating axons gradually increased in number, especially beneath the pial and perivascular surfaces of the lesion, where an abundance of regenerating axons was found 3 months after treatment. A few of these axons were abnormally remyelinated by oligodendrocytes.

In addition to this axonal regeneration through the intraoptic nerve compartment, fine regenerating axons were seen growing out through GLM into the pial connective tissue 3 weeks after treatment. Astrocyte endfeet of the GLM became irregular in contour, protruding in a fern-leaf fashion into the pial connective tissue. Fine naked axons grew out through these protrusions and subsequently increased in number, vigorously growing in large bundles both proximally and distally along blood vessels in the pial connective tissue. Bundles of regenerating axons extended as much as 1.5 mm from the site of the lesion 3 months after surgery. These bundles were covered by thin processes of pial or arachnoidal non-neuronal cells, and the regenerating axons remained unmyelinated.

The above findings indicate that under well-nourished conditions, adult mammalian optic nerve exhibits considerable regenerative ability.
Laser-assisted nerve repair in primates
Authors: Bailes Julian E. , Cozzens Jeffrey W. , Hudson Alan R. , Kline David G. , Ciric Ivan , Gianaris Peter , Bernstein Lawrence P. , Hunter Daniel
Published: May 2009

✓ Studies on the peripheral nerves in rats and other species have helped in the development of laser-assisted nerve anastomosis (LANA), but offer little in evaluating the efficacy of this technique in primates. The authors present a study of LANA in the peripheral nerves of rhesus monkeys. Twelve adult rhesus monkeys underwent bilateral resection of a portion of the peroneal nerve followed by placement of autogenous sural nerve interposition fascicular grafts. The grafts were completed with conventional microsurgical suture technique on one side and with LANA on the other. At 5, 8, 10, and 12 months, the grafted nerves were evaluated for continuity, nerve conduction, and histology (both light and electron microscopy). No significant difference in continuity, conduction velocity, nerve degeneration, nerve regeneration, axon fiber number, or axon fiber density was found in any animal between grafts performed by conventional microsuture and LANA grafts. There was no difference in distal or proximal myelinated fiber density between the LANA grafts and the conventional microsuture grafts. It was concluded that LANA is as effective as microsurgical suture nerve anastomosis in a primate model of nerve repair and grafting.
Physostigmine in the treatment of intrathecal baclofen overdose
Authors: Müller-Schwefe Gerhard , Penn Richard D.
Published: May 2009

✓ The expanding use of intrathecal baclofen for spasticity has raised a concern about the treatment of overdose in these patients, since no specific baclofen antagonist is available. Since physostigmine has been reported to reverse the respiratory depression and somnolence due to opiates, the drug was tried for the treatment of baclofen overdose. In three cases, intravenous physostigmine (2 mg) completely reversed the respiratory depression and coma caused by boluses of 80 to 800 µg of lumbar intrathecal baclofen. Physostigmine, although not a specific antagonist, should provide increased safety for patients receiving intrathecal baclofen.
Cushing Oration, 1989: Who manages the managers?
Authors: Cooper Theodore
Published: May 2009

✓ New medical knowledge is emerging at a tremendous rate. Diseases such as Alzheimer's disease, Parkinson's disease, cancer, and others (diseases once considered beyond the scope of medicine) are receiving a great deal of attention. Yet it is a paradox that, at a time when we are learning more about the biology of the human being, it is more difficult to creatively develop the new knowledge into diagnostic tests, surgical interventions, and preventive strategies.

The pace of biomedical innovation is being slowed by an increase in the intervention of nonmedical “managers of care.” The driving force behind managed care is concern over cost. The managers of medical care have sought to control costs by controlling the doctor's decision making. This is the focus of managed care. The physicians of today, therefore, face a remarkable challenge. They must respond to the needs of patients while being held accountable to an increasing number of overseers in the public and private sectors. These managers of care justify their activities on the notion that the patient will be better off and the cost less if the doctor-patient encounter is regulated by protocols, statistical comparison, utilization review, and fee schedules.

While doctor's decisions are being managed by others, who is managing the managers? The answer should be the medical community, principally doctors. Unfortunately, the answer at the moment is the payors — governmental reimbursement agencies, intermediaries, employers, hospitals, or new corporations designed to manage medical costs. The challenge to the physician is to retain the responsibility for those things for which he or she is held accountable. The challenge should not be ignored.
Cortical language localization in left, dominant hemisphere
Authors: Ojemann George , Ojemann Jeff , Lettich E. , Berger M.
Published: May 2009

✓ The localization of cortical sites essential for language was assessed by stimulation mapping in the left, dominant hemispheres of 117 patients. Sites were related to language when stimulation at a current below the threshold for afterdischarge evoked repeated statistically significant errors in object naming. The language center was highly localized in many patients to form several mosaics of 1 to 2 sq cm, usually one in the frontal and one or more in the temporoparietal lobe. The area of individual mosaics, and the total area related to language was usually much smaller than the traditional Broca-Wernicke areas. There was substantial individual variability in the exact location of language function, some of which correlated with the patient's sex and verbal intelligence. These features were present for patients as young as 4 years and as old as 80 years, and for those with lesions acquired in early life or adulthood. These findings indicate a need for revision of the classical model of language localization. The combination of discrete localization in individual patients but substantial individual variability between patients also has major clinical implications for cortical resections of the dominant hemisphere, for it means that language cannot be reliably localized on anatomic criteria alone. A maximal resection with minimal risk of postoperative aphasia requires individual localization of language with a technique like stimulation mapping.
Short-term psychological outcome of anterior temporal lobectomy
Authors: Hermann Bruce P. , Wyler Allen R. , Ackerman Bette , Rosenthal Ted
Published: May 2009

✓ The purpose of this investigation was to determine the short-term behavioral and emotional effects of anterior temporal lobectomy (ATL). Forty-one patients who underwent ATL were administered a standardized measure of emotional adjustment (Mental Health Inventory) on four occasions: preoperatively, and 1,3, and 6 months postoperatively. Patients who were rendered totally seizure-free by ATL showed significant improvements on multiple indices of psychological distress and psychological well-being, improvement that continued up to 3 months after surgery and remained constant at 6 months postoperatively. Patients who were significantly improved (> 75% reduction in seizure frequency) but continued to experience some seizure activity showed no significant improvements in behavioral or emotional adjustment. The clinical and theoretical significance of these findings is discussed, and it is suggested that functional outcome (for instance, mental health) following ATL may be best predicted by a binary seizure outcome classification (seizure-free or not seizure-free).
Prognostic implications of the bromodeoxyuridine labeling index of human gliomas
Authors: Hoshino Takao , Prados Michael , Wilson Charles B. , Cho Kyung Gi , Lee Kyu-Sung , Davis Richard L.
Published: May 2009

✓ This study includes 182 patients with intracranial gliomas who received bromodeoxyuridine (BUdR), 200 mg/sq m intravenously, at the time of craniotomy but before tumor biopsy. The tumor specimens were stained for BUdR using the immunoperoxidase method; the BUdR labeling index (LI), or S-phase fraction, was calculated as the percentage of BUdR-positive cells. The median BUdR LI's for 127 primary moderately anaplastic astrocytomas, highly anaplastic astrocytomas, and glioblastomas (< 1%, 2.7%, and 7.3%, respectively; range 0% to 38.1%) were not significantly different from those of 55 similar recurrent tumors (< 1%, 4.3%, and 7.4%, respectively; range 0% to 30.5%). The mean LI was significantly higher in tumors from patients over 50 years of age than in tumors from younger patients (p < 0.001). This age-related difference in LI's was found in both groups of patients with astrocytomas but not in those with glioblastomas. Kaplan-Meier survival curves showed a significantly greater probability of survival among patients whose tumors had LI's of less than 1% than among those with LI's greater than 5%; survival probability of patients with tumor LI's of 1% to 5% was intermediate between the two extremes. Thus, the BUdR LI appears to reflect the proliferative potential more accurately than the histopathological diagnosis and should therefore be considered an important factor in determining the prognosis of individual patients with intracranial gliomas and in selecting their treatment.
Use of thallium-201 SPECT to quantitate malignancy grade of gliomas
Authors: Black Keith L. , Hawkins Randall A. , Kim Kenneth T. , Becker Donald P. , Lerner Carole , Marciano Donna
Published: May 2009

✓ A quantitative preoperative technique using thallium-201 single-photon emission computerized tomography is described which predicts whether specific gliomas are of high- or low-grade malignancy. An index, based on the ratio of thallium uptake in the tumor versus the homologous contralateral brain, was calculated and compared with tumor histology. The index in 14 patients with low-grade malignant gliomas was 1.27 ± 0.40 in contrast to an index of 2.40 ± 0.61 in 11 patients with high-grade malignant gliomas (p < 0.0005). Whether gliomas were of low- or high-grade malignancy could be predicted with 89% accuracy using a threshold of 1.5. Low-grade gliomas with an index higher than 1.5 acted biologically more like high-grade tumors, and no tumor histologically classified as being of high-grade malignancy had an index lower than 1.7. This technique could help to reduce unrecognized sampling errors during needle biopsies of brain tumors, particularly of high-grade lesions classified in error as low-grade tumors due to inadequate biopsy material.
The prediction of recurrence in meningiomas
Authors: May Paul L. , Broome John C. , Lawry John , Buxton Robert A. , Battersby Robert D. E.
Published: May 2009

✓ Despite the complete macroscopic excision of meningiomas, there is a significant rate of recurrence approaching 20% at 20 years. The prediction of recurrence by clinical and histopathological means is inadequate. Flow cytometric analysis of deoxyribonucleic acid (DNA) in meningiomas has shown a correlation between a high proliferative index based on tumor cell-cycle stage (%S + %G2/M) and clinically aggressive behavior. Accordingly, the DNA analysis of meningioma tissue may be of value in predicting recurrence of these tumors. To test this hypothesis, the DNA of paraffin-embedded archival tissue from known recurrent meningiomas was compared with an age- and sex-matched nonrecurrent group. Both groups had comparable follow-up periods.

Forty patients with total macroscopic removal at the time of surgery were analyzed. The paraffin blocks of these tumors were retrieved and reclassified histologically according to the World Health Organization system. Sections were then taken for flow cytometric study. The DNA analysis showed that the proliferative index of the recurrent group was significantly higher than that of the nonrecurrent group (p < 0.002), although the histological subtyping of the two groups was similar. These results support the suggestion that flow cytometry may be of value in the prediction of recurrence of histologically benign, macroscopically removed meningiomas.
Complex dural arteriovenous fistulas
Authors: Barnwell Stanley L. , Halbach Van V. , Higashida Randall T. , Hieshima Grant , Wilson Charles B.
Published: May 2009

✓ Of the 88 patients evaluated for symptomatic dural arteriovenous (AV) fistula over the past 8 years, 16 had large or complicated lesions that could not be treated with standard transvascular approaches or in which such treatment had been unsuccessful. Eleven fistulas were located in the transverse sinus, two in the cavernous sinus, two in the straight sinus, and one in the falx-tentorial region near the vein of Galen. The patients were treated with a combination of endovascular and neurosurgical techniques. Fourteen patients underwent preoperative transarterial embolization; this procedure closed the fistula in one patient. In the remaining 15 patients, surgery was performed to provide access to the fistula for embolization from either the venous or the arterial side, or for excision of the fistula. Transvenous embolization completely obliterated the fistula in seven of nine patients; the fistulas were embolized incompletely through the feeding arteries in two patients; and complete surgical resection of the lesion was accomplished in four patients. Complications related to venous occlusion occurred in two patients and one patient suffered communicating hydrocephalus that was effectively treated by shunting. There were no deaths. The results suggest that combined endovascular and neurosurgical techniques are a safe and effective means for the treatment of selected complex dural AV fistulas.
Parapontine trigeminal cryptic angiomas presenting as trigeminal neuralgia
Authors: Tsubaki Shin-ichi , Fukushima Takanori , Tamagawa Teruaki , Miyazaki Shin-ichiro , Watanabe Kazuo , Kuwana Nobumasa , Shimizu Tsuneo
Published: May 2009

✓ Posterior fossa microvascular decompression surgery was attempted in 1257 patients with trigeminal neuralgia (TN), of whom seven had a very unusual cryptic angioma. The lesions were not visualized on preoperative enhanced computerized tomography scans, and serial angiography demonstrated a small vascular stain in only one case. The character of the facial pain was indistinguishable from TN caused by vascular compression and there was no other specific symptomatology. The patients' age and sex distributions were also compatible with classical TN. Cryptic angiomas presenting as typical TN without other symptoms have not been reported before, but they should be kept in mind in the differential diagnosis and surgical management of TN.
Liposomes coupled with monoclonal antibodies against glioma-associated antigen for targeting chemotherapy of glioma
Authors: Kito Akira , Yoshida Jun , Kageyama Naoki , Kojima Nakao , Yagi Kunio
Published: May 2009

✓ Liposomes have a variety of attributes as a drug delivery system. Targeting of liposomes to specific cells has been investigated by using appropriate cytophilic ligands such as monoclonal antibodies (MAb's). In the present study, liposomes with selective cytotoxicity toward glioma cells were obtained. An MAb which reacts with a glioma-associated antigen, G-22-MAb, was coupled with liposomes by the cross-linking reagent dipalmitoyl L-α-phosphatidylethanolamine 3-(2-pyridyldithio)propionate. Interaction of the liposomes with glioma cells was morphologically observed by fluorescence microscopy, and uptake of liposomal contents into glioma cells was analyzed by flow cytometry using carboxyfluorescein as a marker. It was demonstrated that G-22-MAb could be coupled with liposomes without altering its specificity toward glioma cells and that coupling with the MAb led to a significant increase in the uptake of liposomal contents into glioma cells. Liposomes containing an antitumor drug, methotrexate (MTX), were prepared and their cytotoxicity was examined by a colorimetric growth assay. Upon incorporation of MTX into the MAb-coupled liposomes, the cytotoxicity toward glioma cells was increased 100-fold as compared with free MTX. These results indicate that G-22-MAb-coupled liposomes containing MTX have selective cytotoxicity toward glioma cells and could be utilized for targeting the chemotherapy of gliomas.
Lipid peroxidation in focal cerebral ischemia
Authors: Kinuta Yuji , Kikuchi Haruhiko , Ishikawa Masatsune , Kimura Mieko , Itokawa Yoshinori
Published: May 2009

✓ To verify whether lipid peroxidation is associated with focal cerebral ischemia, a unilateral middle cerebral artery occlusion was carried out in rats. The concentrations of various endogenous antioxidants in the ischemic center were measured, including α-tocopherol and ubiquinones as lipid-soluble antioxidants and ascorbate as a water-soluble antioxidant. At 30 minutes after ischemia, α-tocopherol decreased to 79% of baseline, reduced ubiquinone-9 to 73%, ubiquinone-10 to 66%, and reduced ascorbate to 76%. Six hours after ischemia, α-tocopherol decreased to 63% and reached a plateau, whereas reduced ubiquinones and reduced ascorbate declined further to 16% and 10%, respectively, 12 hours after ischemia and then reached plateau levels. These results suggest functional and durational differences between antioxidants and lipid peroxidation in this ischemic model. Although the reciprocal increase in oxidized ubiquinones during ischemia was not observed, that of oxidized ascorbate was noted. The complementary antioxidant system between cytoplasmic and membranous components, the combination α-tocopherol/ascorbate, was estimated from the calculated consumption ratio of these antioxidants on the basis that the loss of these reduced antioxidants is due to neutralization of free radicals. This system is suggested to play an important role in the early ischemic period. Urate also increased during ischemia. The possible involvement of the xanthine-xanthine oxidase system in initiating free radical reactions in cerebral ischemia is also discussed.
Alterations of mechanical properties in canine basilar arteries after subarachnoid hemorrhage
Authors: Kim Phyo , Sundt Thoralf M. , Vanhoutte Paul M.
Published: May 2009

✓ The purpose of this study was to examine the hypotheses that structural stiffening of the arterial wall contributes to chronic cerebral vasospasm, and that alteration in properties of smooth muscle takes place after subarachnoid hemorrhage (SAH). Subarachnoid hemorrhage and subsequent chronic vasospasm were induced in dogs by two cisternal injections of autologous blood (on Day 0 and Day 2). Vasospasm was confirmed by angiography performed on Day 0 and Day 7. Animals in the control group underwent angiography only. On Day 8, the mechanical properties of the basilar arteries were studied in vitro. Passive compliance, measured under total inhibition of spontaneous myogenic tone with diltiazem (10−4 M) plus papaverine (10−4 M) was smaller in the SAH group. The length-contraction curve was shifted to the left and the optimum length for maximum contraction (Lmax) was significantly shorter in the spastic blood vessels. The spontaneous myogenic tone was augmented in the SAH group, resulting in an increase in resting tension at each length. By contrast, the maximum contractions in response to KCl and uridine 5′-triphosphate were markedly reduced in the SAH group, without changes in sensitivity to these agents. These differences in mechanical properties were observed in rings both with and without endothelium. The results indicate that, in chronic vasospasm, stiffening of the noncontractile component of the vasculature takes place as well as alterations in the contractile component, both of which presumably contribute to the shift in resting length-tension relationship and length-contraction relationship of the artery. The decreased distensibility, the increase in resting tension, and the shortening of the Lmax all favor a smaller diameter of the artery after SAH, possibly contributing to vasospasm.
Brain kininogen following experimental brain injury: evidence for a secondary event
Authors: Ellis Earl F. , Chao Julie , Heizer Marcia L.
Published: May 2009

✓ Previous studies have shown that following experimental brain injury cerebral arterioles dilate and display endothelial lesions and reduced responsiveness to hypocapnia. These abnormalities are caused by cyclooxygenase-dependent free radical generation. There is evidence that the kallikrein-kinin system may in part stimulate the cyclooxygenase-dependent damage since bradykinin is a powerful stimulator of prostaglandin formation and it has recently been shown that a specific kinin receptor blocker decreases the arteriolar abnormalities caused by injury. In order to further examine the hypothesis that the kallikrein-kinin system is important in inducing damage, rat brain tissue was examined for kininogen, the precursor of kinins, at 10 minutes and 1, 3, 6, 15, 24, 48, and 72 hours after injury. A fluid-percussion brain injury device was attached over the right cerebral cortex of rats and a 1.6-atmosphere pressure injury was administered. The kininogen content was determined by a radioimmunoassay procedure in tissues which were free of intravascular blood.

After injury, bleeding was confined mainly to the right hemisphere. The kininogen content in the right hemisphere was significantly elevated by one hour after injury, continued to rise until 15 hours after injury, then was significantly decreased by 2 days after injury. In the left hemisphere, kininogen was significantly elevated at 1 hour postinjury, returned toward control levels over the 3- to 6-hour period after injury, then was again elevated at 15 hours after injury. These studies also show that brain water and cerebrovascular permeability were greater at 15 hours postinjury than at earlier time points. The data further support a role for the kallikrein-kinin system in brain injury and, when considered with the results of other studies, suggest that a secondary event is occurring in the 12- to 24-hour period after neural injury. The authors hypothesize that this secondary event is related to endothelial and vascular repair and may be important for the return of normal cerebrovascular function.
Diagnostic yield in CT-guided stereotactic biopsy of gliomas
Authors: Greene George M. , Hitchon Patrick W. , Schelper Robert L. , Yuh William , Dyste Gregg N.
Published: May 2009

✓ Twenty-seven patients underwent 29 computerized tomography (CT)-guided stereotactic biopsy procedures for untreated or recurrent malignant astrocytomas. Biopsies were obtained from the hypodense center, enhancing margin, and hypodense periphery as seen on contrast-enhanced CT scans, with diagnostic yields of (number of biopsies yielding tumor/number of biopsies obtained): 34/61 (56%), 68/101 (67%), and 8/22 (36%) from these three zones, respectively. Although tumor was identified in all three zones, diagnostic yield was significantly higher in the hypodense center and enhancing margin. Comparison of patients with untreated tumors to those with recurrent tumors demonstrated no statistical difference in tumor distribution, although there was a trend toward a higher yield from the hypodense periphery in the recurrent tumor group. Tumor was found up to 15 mm beyond the CT-enhancing margin, in addition to extending beyond the area of abnormality on T2-weighted magnetic resonance images. These findings suggest that serial stereotactic biopsies should be targeted to the hypodense center and enhancing margin for improved diagnostic yield. Biopsy material obtained from the hypodense periphery that demonstrates tumor also indicates that a tumor volume beyond the confines of the CT-enhancing margin should be considered when calculating dosimetry for interstitial radiation.
Intracranial pressure monitoring in the posterior fossa: a preliminary report
Authors: Rosenwasser Robert H. , Kleiner Laurence I. , Krzeminski Joseph P. , Buchheit William A.
Published: May 2009

✓ Direct therapeutic drainage and intracranial pressure monitoring from the posterior fossa has never been accepted in neurosurgical practice. Potential complications including cerebrospinal fluid leak, cranial nerve palsies, and brain-stem irritation have been a major deterrent. The authors placed a catheter for pressure monitoring in the posterior fossa of 20 patients in the course of posterior fossa surgery: 14 patients with acoustic schwannomas, four with posterior fossa meningiomas, one with cerebellar hemangioblastoma, and one with a solitary cerebellar metastatic lesion. A Richmond bolt was also placed in the frontal area.

Continuous monitoring of the supratentorial and infratentorial compartments was performed for 48 hours. During the first 12 hours the posterior fossa pressure was 50% greater than that of the supratentorial space in all patients (p < 0.01). Over the next 12 hours the supratentorial pressure was 10% to 15% higher than the posterior fossa pressures in all patients, and by 48 hours of monitoring the pressures had equilibrated. There was no mortality or morbidity referable to insertion of the posterior fossa catheter.

The conclusions drawn from this study are that: 1) direct monitoring and drainage of the posterior fossa is safe and effective; and 2) within the early postoperative period, the supratentorial pressures failed to reflect what is taking place within the posterior fossa. The implications and advantages of direct posterior fossa monitoring in the postoperative patient are discussed.
Trigeminal neurinomas: operative approach in eight cases
Authors: Yasui Toshihiro , Hakuba Akira , Kim Soo Han , Nishimura Shuro
Published: May 2009

✓ The authors report eight cases of trigeminal neurinoma managed over the past 13 years with radical resection at a single-stage operation. Three patients were male and five were female, ranging in age from 25 to 56 years (mean 41.5 years). One had von Recklinghausen's disease. The tumors were located mainly within the middle fossa in two cases and within the posterior fossa in two, and extended both supra- and infratentorially in four cases. Facial pain and hearing disturbance were the main symptoms, with various other symptoms such as focal seizures, hemiparesis, gait disturbance, increased intracranial pressure, and visual disturbance also being noted. All patients underwent radical tumor resection with either a transpetrosal transtentorial or orbitozygomatic infratemporal surgical approach; the approach depended on the topography of the tumor. Total removal was performed in all cases. Only one patient, treated early in the series, required a second operation to remove the tumor completely. In another case the tumor recurred 5 years after the operation. There has been no operative mortality, but injury or permanent damage to the trigeminal branches was inevitable in many cases. The surgical results were excellent in three patients and good in five.
Detachable balloon embolization therapy of posterior circulation intracranial aneurysms
Authors: Higashida Randall T. , Halbach Van V. , Cahan Leslie D. , Hieshima Grant B. , Konishi Yoshifumi
Published: May 2009

✓ Treatment of complex and surgically difficult intracranial aneurysms of the posterior circulation is now being performed with intravascular detachable balloon embolization techniques. The procedure is carried out under local anesthesia from a transfemoral arterial approach, which allows continuous neurological monitoring. Under fluoroscopic guidance, the balloon is propelled by blood flow through the intracranial circulation and, in most cases, can be guided directly into the aneurysm, thus preserving the parent vessel. If an aneurysm neck is not present, test occlusion of the parent vessel is performed and, if tolerated, the balloon is detached.

Twenty-six aneurysms in 25 patients have been treated by this technique. The aneurysms have involved the distal vertebral artery (five cases), the mid-basilar artery (six cases), the distal basilar artery (11 cases), and the posterior cerebral artery (four cases). The aneurysms varied in size and included three small (< 12 mm), 15 large (12 to 25 mm), and eight giant (> 25 mm). Fifteen patients (60%) presented with hemorrhage and 10 patients (40%) with mass effect. In 17 cases (65%) direct balloon embolization of the aneurysm was achieved with preservation of the parent artery. In nine cases (35%), because of aneurysm location and size, occlusion of the parent vessel was performed. Complications from therapy included three cases of transient cerebral ischemia which resolved, three cases of stroke, and five deaths due to immediate or delayed aneurysm rupture. The follow-up period has ranged from 2 months to 43 months (mean 22.5 months).

In cases where posterior circulation aneurysms have been difficult to treat by conventional neurosurgical techniques, intravascular detachable balloon embolization may offer an alternative therapeutic option.
Implantation of human meningiomas into the subrenal capsule of the nude mouse
Authors: Medhkour Azedine , Van Roey Melinda , Sobel Raymond A. , Fingert Howard J. , Lee Jungkyo , Martuza Robert L.
Published: May 2009

✓ To develop a reproducible in vivo model for the growth of human meningiomas, meningiomas from 16 patients were implanted into the subrenal capsule of the nude mouse. In eight experiments solid tumor implants taken directly from surgical specimens were used, in four experiments the implants were made from early-passage monolayer cell cultures, and in four experiments both techniques were used. Successful tumor growth was observed in 10 (83%) of the 12 solid tumor implants and in six (75%) of the eight implants from cell cultures. The size and neovascularization of these tumors were serially determined over a 3-month period. Tumor doubling occurred in 1 to 3 weeks in all of the solid tumor implant group. In the group of six tumors successfully implanted from cell cultures, three doubled in 1 to 3 weeks and three grew more rapidly, reaching 10 to 20 times their original volume. Neovascularity occurred in the tumors within 3 weeks of implantation. Each of the solid tumor implants had a histological pattern similar to that of the corresponding original specimen. Only three of those implanted from cell cultures were similar to the original tumor; the other three displayed features characteristic of malignant meningioma. These studies suggest that implantation of human meningiomas in the subrenal capsule of the nude mouse is a feasible model that may be useful for evaluating hormonal or genetic modulation of tumor growth and for testing potential treatment regimens.
Relaxant effect of calcitonin gene-related peptide on cerebral arterial spasm induced by experimental subarachnoid hemorrhage in dogs
Authors: Nozaki Kazuhiko , Uemura Yoshihiko , Okamoto Shinichiro , Kikuchi Haruhiko , Mizuno Noboru
Published: May 2009

✓ This study examines the relaxant effect of calcitonin gene-related peptide (CGRP), a 37-amino acid peptide with a potent vasodilator action, on cerebral arterial spasm after subarachnoid hemorrhage (SAH). The spasm was induced by injecting autologous arterial blood percutaneously into the cisterna magna in adult mongrel dogs. The single-injection model of SAH was produced by injection of 1.0 ml/kg body weight of blood (on Day 0), and the double-injection model involved two successive injections of 0.5 ml/kg body weight of blood made 48 hours apart (on Day 0 and Day 2). On vertebral angiograms, arterial narrowing of the major cerebral arteries was most prominent on Day 3 after SAH in the single-injection model and on Day 7 in the double-injection model. When 10−10 mol/kg of CGRP was administered intracisternally in the single-injection model on Day 3, the diameter of the spastic cerebral arteries, as determined by angiography, recovered to normal. After intracisternal administration of 10−11 to 2 × 10−10 mol/kg of CGRP on Day 7 in double-injection models, spastic cerebral arteries dilated in a dose-dependent manner. The dilatory effect of CGRP continued for a few hours after administration. The results suggest that CGRP injected intracisternally may reverse cerebral arterial spasm after SAH.