bluuebunny/crossref_metadata_2025 huggingface dataset:
The pseudodelta sign in acute head trauma
Authors: Yeakley Joel W. , Mayer John S. , Patchell Larry L. , Lee K. Francis , Miner Michael E.
Published: May 2009

✓ The “delta sign” is a triangular area of high density with a low-density center seen on contrast-enhanced computerized tomography (CT) scans in the location of the superior sagittal sinus. It indicates thrombosis of the sinus. The authors describe the “pseudodelta sign,” which is similar but is seen on non-contrast-enhanced CT scans and which has a high correlation with hemorrhage secondary to acute head trauma.
Changes in CSF pressure after mannitol in patients with and without elevated CSF pressure
Authors: Ravussin Patrick , Abou-Madi Mounir , Archer David , Chiolero René , Freeman James , Trop Davy , De Tribolet Nicolas
Published: May 2009

✓ In view of the current concern that rapid infusion of mannitol might initially aggravate intracranial hypertension, the effects of a mannitol infusion on lumbar cerebrospinal fluid pressure (CSFP) were investigated in 49 patients. The studies were performed when the patients were under general anesthesia prior to elective craniotomy for tumor resection or intracerebral aneurysm clipping. The patients were divided into two groups: 24 patients with normal CSFP (Group I, mean CSFP 10.5 mm Hg) and 25 with raised CSFP (Group II, mean CSFP 20.8 mm Hg). Measurements of CSFP, mean arterial blood pressure (MABP), and central venous pressure (CVP) were made serially during and after the infusion of 20% mannitol (1 gm ⋅ kg−1 infused over a 10-minute interval). In both groups, mannitol infusion provoked a fall in MABP and an increase in CVP. An immediate increase in CSFP was observed in Group II, whereas CSFP increased transiently but significantly in Group I. Analysis of the arterial and venous driving pressures which contribute to CSFP suggests that the transient increase in CSFP after mannitol in Group I was partly due to the increase in CVP. The presence of intracranial hypertension may thus alter the CSFP response to arterial and venous pressure changes.

Cerebral blood volume (CBV) was measured in dogs in a separate study analogous to the human protocol. The CBV increased approximately 25% over control values after mannitol infusion both in the normal animals and in those with CSFP raised by an epidural balloon. The response of the CSFP to mannitol infusion differed between both groups in a fashion similar to that observed in the human subjects. Thus, differences in CBV changes after mannitol do not account for the difference in CSFP response between normal subjects and those with raised CSFP.
The influence of nimodipine on cerebral blood flow autoregulation and blood-brain barrier
Authors: Höllerhage Hans-Georg , Gaab Michael R. , Zumkeller Matthias , Walter Gerhard F.
Published: May 2009

✓ Twenty anesthetized rats were randomly assigned to a nimodipine-treated group or a control group of 10 rats each. Local cerebral blood flow (lCBF) was measured by means of a surface electrode using the hydrogen clearance technique. Systemic arterial pressure (SAP) was varied with administration of norfenefrine or by hemorrhage in order to obtain SAP/cerebral blood flow (CBF) curves under different conditions. In the control group, a typical autoregulation curve was obtained with an lCBF plateau between 70 and 120 mm Hg SAP. The nimodipine-treated animals, however, showed only a slight diminution in the slope of the curve but no real plateau, indicating impairment of CBF autoregulation. In another series, 20 anesthetized rats were randomly assigned to a treatment group or a control group of 10 animals each. Intravenous Evans blue dye was used as a tracer for blood-brain barrier (BBB) function. In both groups, SAP was raised to a level of 180 mm Hg with administration of norfenefrine for 6 minutes. Extravasation of significantly more Evans blue dye was observed in the nimodipine group than in the control group, indicating impairment of the BBB. It is concluded that nimodipine may impair CBF autoregulation, allowing damage to the BBB under hypertensive conditions.
Myelopathy due to intracranial dural arteriovenous fistulas draining intrathecally into spinal medullary veins
Authors: Wrobel Charles J. , Oldfield Edward H. , Di Chiro Giovanni , Tarlov Edward C. , Baker Richard A. , Doppman John L.
Published: May 2009

✓ Arteriovenous malformations (AVM's) of the spine commonly cause progressive myelopathy. Occasionally, myelography reveals serpentine filling defects characteristic of a spinal AVM, but an AVM or arteriovenous (AV) fistula cannot be demonstrated arteriographically, despite selective catheterization of all vessels known to have the potential of supplying the spinal cord and spinal dura. Often, and particularly in the setting of subacute or acute deterioration, this has been attributed to spontaneous thrombosis of the veins (the Foix-Alajouanine syndrome). Three patients are reported in whom intracranial dural AV fistulas, supplied by branches of the internal and external carotid arteries, drained into spinal veins and produced myelopathy. In one patient, motor and sensory deficits were limited to the lower extremities. In all three patients, disconnection of the fistula from its spinal venous drainage permitted arrest of a rapidly progressive myelopathy and partial recovery. These findings indicate that some patients who appear to have spinal cord AVM's but exhibit negative spinal arteriography are suffering from cranial dural AV fistulas and therefore need carotid as well as spinal arteriography. The considerable distance of these fistulas from the level of neurological expression supports venous hypertension as a pathophysiological mechanism of spinal cord injury. Interruption of a cranial dural fistula draining into spinal veins permits recovery of the myelopathy.
Direct carotid sinus approach to treatment of bilateral carotid-cavernous fistulas
Authors: Albert Pedro , Polaina Manuel , Trujillo Francisco , Romero José
Published: May 2009

✓ The authors present a patient with a complex vascular malformation composed of bilateral spontaneous carotid-cavernous fistulas (CCF's). The abnormality was supplied on the right side by the right external carotid artery (ECA) and the right internal carotid artery (ICA), and on the left side only by the left ICA. There was also an arteriovenous communication between the right ECA and the lateral sinus. Surgical embolization of both cavernous sinuses with oxidized cellulose was achieved on one side by direct puncture and on the other through one of its venous affluents, successfully occluding both CCF's and preserving the patency of both ICA's without any neurological deficit. The arteriovenous communication between the right ECA and the lateral sinus was occluded by embolization of the occipital artery and ligation of the right ECA.
Hemangioblastomas of the central nervous system
Authors: Neumann Hartmut P. H. , Eggert Hans R. , Weigel Klaus , Friedburg Hartmut , Wiestler Otmar D. , Schollmeyer Peter
Published: May 2009

✓ The findings of a 10-year study (1976 to 1986) conducted in southwest Germany on hemangioblastomas (HBL's) of the central nervous system (CNS) are presented. During that period, 47 HBL's were diagnosed and surgically removed in 44 patients, with a good postoperative survival rate and prognosis. The majority (83%) of these tumors were located in the cerebellum. By thorough clinical examination of the patients and careful evaluation of their family background, it was found that 23% of the HBL patients were afflicted with von Hippel-Lindau syndrome. In addition to the CNS tumors, 14 neoplastic or similar lesions were detected in other tissues. These included angiomatosis of the retinae, pheochromocytomas, pancreatic cysts, renal cysts, and renal carcinoma. The diagnosis of von Hippel-Lindau syndrome was thus established in seven families. The authors suggest the need for a screening program for patients with HBL of the CNS which is designed to confirm or exclude ocular or visceral lesions associated with von Hippel-Lindau syndrome.
Clinical results of extracranial-intracranial bypass surgery in patients with hemodynamic cerebrovascular disease
Authors: Powers William J. , Grubb Robert L. , Raichle Marcus E.
Published: May 2009

✓ The importance of hemodynamic factors in the pathogenesis and treatment of cerebrovascular disease remains uncertain. The extracranial-intracranial (EC-IC) bypass trial has been criticized for failing to identify and separately analyze those patients with chronic reduction in regional cerebral perfusion pressure (rCPP) who might be most likely to benefit from surgery. Positron emission tomography (PET) measurements of regional cerebral blood flow (rCBF) and blood volume (rCBV) were performed on 29 patients with symptomatic occlusion or intracranial stenosis of the carotid arterial system prior to undergoing EC-IC bypass surgery. Twenty-four patients had evidence of reduced rCPP (increased rCBV/rCBF ratio) distal to the arterial lesion. Of 21 patients who survived surgery without stroke, three suffered ipsilateral ischemic strokes during the 1st postoperative year. A nonrandomized control group of 23 nonsurgical patients with similar clinical, arterio-graphic, and PET characteristics experienced no ipsilateral ischemic strokes during the 1st year following PET. Based on these results in 44 patients, the probability that successful surgery reduces the occurrence of ipsilateral ischemic stroke 1 year later was calculated. This probability ranged from 0.045 for a 50% reduction to 0.168 for a 10% reduction. Thus, there was little evidence to suggest that measurements of cerebral hemodynamics can identify a group of patients who would benefit from EC-IC bypass surgery.
Axon regeneration through blood vessel allografts after cyclosporine treatment
Authors: Gulati Adarsh K.
Published: May 2009

✓ The present study describes the usefulness of blood vessel allografts to repair gaps in rat peripheral nerve after immunosuppression with cyclosporine. Isogeneic strains of rats with known histoincompatibility were used for this study. A 10-mm gap was created in the peroneal nerve of host Fischer rats. The gap was bridged by a 12-mm section of internal carotid artery removed from a Buffalo strain of rat. The host rats were divided into two groups. One group received no immunosuppression, whereas the other group was treated with cyclosporine. Untreated control rats immunologically rejected the allografted vessels and were unable to support host axonal regeneration through them. On the other hand, in cyclosporine-treated rats the allografted vessels survived. The regenerating host axons reorganized to form a functional nerve within the vessel conduit. The regenerated axons persisted even after rejection of the allografted vessel caused by cessation of immuno-therapy. These results show that blood vessel allografts can serve as an effective conduit for reorganization of regenerated nerves and can bridge gaps in peripheral nerves.
Synovial chondromatosis of the temporomandibular joint with intracranial extension
Authors: Daspit C. Phillip , Spetzler Robert F.
Published: May 2009

✓ The authors report the unusual presentation of an intracranial extension of synovial chondromatosis of the temporomandibular joint. The patient presented with a peripheral facial nerve paralysis and anacusis. Computerized tomography revealed the lesion, but fine-needle biopsy was inconclusive. Craniotomy with removal of the tumor was performed, and pathological studies confirmed the diagnosis. The facial nerve dysfunction was thought to be secondary to direct neural compression.
Intratumoral LAK cell and interleukin-2 therapy of human gliomas
Authors: Barba David , Saris Stephen C. , Holder Carol , Rosenberg Steven A. , Oldfield Edward H.
Published: May 2009

✓ Adoptive immunotherapy using lymphokine-activated killer (LAK) cells and interleukin-2 (IL-2) offers the possibility of a new treatment for patients with malignant glial tumors. In a clinical trial, the effectiveness of a 5-day treatment cycle of direct intratumoral administration of both LAK cells and IL-2 via a reservoir/catheter system in patients with recurrent malignant gliomas was studied. Ten patients were entered into the study, nine of whom were treated with 15 cycles of LAK cells (0.9 to 21.0 × 109 cells) and IL-2 (49 to 450 × 103 U/kg). The 10th patient in the study was not treated because of the onset of severe neurological deficits prior to beginning immunotherapy. Of the nine patients treated, one had a partial tumor response to immunotherapy as documented by computerized tomography. Neurological side effects occurred in all patients undergoing treatment and were related to increases in cerebral edema that appeared to be mediated by the immunotherapy. This report demonstrates the present limitations of regional adoptive immunotherapy with LAK cells and IL-2 in the treatment of human glial tumors.
High-dose methotrexate for non-AIDS primary central nervous system lymphoma
Authors: Gabbai Alberto A. , Hochberg Fred H. , Linggood Rita M. , Bashir Rifaat , Holteman Kathleen
Published: May 2009

✓ Thirteen patients with primary lymphoma of the central nervous system (CNS) were treated with high-dose intravenous methotrexate (MTX), 3.5 gm/sq m, followed by calcium leucovorin rescue, at 3-week intervals, for three cycles. Eleven patients subsequently received radiation therapy to the whole brain, 30 to 44 Gy. Before radiation therapy, eight patients responded completely and four partially; there was one nonresponder. The median Karnofsky score before high-dose MTX therapy was 60 and increased to 90 after treatment. Five of the eight complete responders reached a Karnofsky rating of 100. The three longest responders (one of whom received MTX only) were without recurrence of their disease at 29+, 32, and 32+ months posttherapy. The median response period is 9+ months. The median survival time from the date of the first MTX treatment is 9+ months, and the three longest survival times are 29+, 32+, and 54+ months.

All patients received corticosteroids in either unchanging or diminishing dosages during therapy. It is concluded that primary CNS lymphoma is sensitive to high-dose MTX, which provides a safe and easily administered adjuvant to radiation therapy for this neoplasm.
Improved tumor-specific immunotoxins in the treatment of CNS and leptomeningeal neoplasia
Authors: Johnson Virginia G. , Wrobel Charles , Wilson Debra , Zovickian John , Greenfield Larry , Oldfield Edward H. , Youle Richard
Published: May 2009

✓ A novel antibody-toxin conjugate has been developed for use in cancer therapy. This report demonstrates that this new reagent selectively kills glioblastoma- and medulloblastoma-derived cell lines, medulloblastoma cells in primary culture, and cell lines derived from tumors commonly metastatic to the cerebrospinal fluid (CSF). Efficient killing of human tumor cells occurred at concentrations between 3.9 × 10−13 M and 1.1 × 10−10 M, whereas guinea pigs and rhesus monkeys tolerated intrathecal levels of 2 × 10−9 M. Cerebrospinal fluid from normal humans and from brain-tumor patients does not inhibit the in vitro efficacy of this reagent. The wide therapeutic window, extreme potency, and general applicability of this antibody-toxin conjugate against CSF-borne primary or metastatic tumors warrants clinical trials.
Flow-cytometric DNA analysis and immunohistochemical measurement of Ki-67 and BUdR labeling indices in human brain tumors
Authors: Nishizaki Takafumi , Orita Tetsuji , Furutani Yasuhiro , Ikeyama Yukihide , Aoki Hideo , Sasaki Kohsuke
Published: May 2009

✓ Cell proliferation potential was assessed by measuring the labeling indices of the monoclonal antibody Ki-67 and of 5-bromodeoxyuridine (BUdR), and the cellular deoxyribonucleic acid (DNA) content in 48 human brain tumors. The diagnostic and prognostic value of flow-cytometric DNA analysis was also evaluated using ethanol-fixed paraffin-embedded BUdR-labeled specimens; these were the same specimens as were used for measuring the BUdR and Ki-67 labeling indices. Both the Ki-67 and the BUdR labeling indices correlated with the degree of malignancy estimated from conventional histological preparations. The Ki-67 labeling index was 1.7 times greater than the BUdR labeling index. The relationship of DNA aneuploidy to the labeling indices or to morphology in cases of glioma was examined. All of the tumors with an aneuploid line corresponded to malignant glioma classified by histological criteria, although malignant glioma did not always show DNA aneuploidy. In addition, the cases with aneuploid lines showed high BUdR and Ki-67 labeling indices. The cell kinetic data, which indicate the biological character of tumors, allowed prediction of the prognosis of the patients with gliomas. In contrast, despite the presence of an aneuploid line, three of 13 meningiomas showed a benign histological pattern without an aggressive clinical course, and neither the Ki-67 nor the BUdR labeling index was high. These results indicate an unequivocal relationship between DNA aneuploidy and clinical behavior; in general, both labeling indices may prove to be objective indicators of the outcome of patients with brain tumors.
Dissociated mesencephalic responses to medial and ventral thalamic nuclei stimulation in rats
Authors: Sakata Shuji , Shima Fumio , Kato Motohiro , Fukui Masashi
Published: May 2009

✓ To investigate the mechanism of analgesia noted with electrical stimulation of the thalamic sensory relay nucleus and medial thalamus, modulations of neuronal activities in the periaqueductal gray matter (PAG) were studied in response to electrical stimulations of the ventroposterolateral nucleus (VPL) and parafascicular nucleus (Pf) and to peripheral noxious stimulations in rats. Extracellular single-unit activities were recorded from 102 neurons in the PAG and the adjacent area in animals under halothane anesthesia.

A large population (83%) of the PAG neurons reacted to Pf stimulations with a predominantly excitatory response, whereas smaller numbers (43%) responded to VPL stimulations. There was a significant correlation between the response characteristics of Pf and noxious stimulations, whereas no correlation was found between VPL and noxious stimulations. The PAG neurons that were verified antidromically to project to the nucleus raphe magnus showed a similar pattern of response. The excitatory response to the Pf stimulation was partially attenuated by systemic administration of naloxone, whereas that to the VPL stimulation was not affected.

These results suggest that part of the analgesic mechanism of medial thalamus stimulation involves activation of the descending pain suppression system by exciting the PAG neurons through the opioid system, while the analgesia produced by sensory relay nucleus stimulation does not involve the PAG neurons or the opioid system.
Meningioangiomatosis in a patient without von Recklinghausen' disease
Authors: Ogilvy Christopher S. , Chapman Paul H. , Gray Mark , de la Monte Suzzane M.
Published: May 2009

✓ Meningioangiomatosis is a rare benign tumor of the central nervous system. Most cases are associated with von Recklinghausen' neurofibromatosis. The case of a 9-year-old boy with a 6-year history of temporal lobe epilepsy is reported. Computerized tomography revealed a hyperdense lesion in the region. The lesion was avascular on angiography. Magnetic resonance imaging showed a large well-demarcated abnormality with hyper- and hypodense regions on T2-weighted images. The abnormality did not extend into the white matter. Histological sections of the biopsy specimen disclosed an organoid transcortical lesion composed of interlacing finger-like fascicles of vascularized fibromeninges. Most fascicles exhibited one or more central slit-like capillaries cuffed by fibroblasts and invaginated meningeal tissue arranged in a parallel or concentric manner. Typical psammoma bodies were evident throughout the lesion, as well as in the intervening, mildly gliotic cerebral cortex. Proliferative meningothelial cells were present in the overlying leptomeninges. The lesion in this case was a hamartoma rather than a neoplasm.
Profound hypothermia and circulatory arrest for aneurysm surgery
Authors: Chyatte Douglas , Elefteriades John , Kim Byung
Published: May 2009

✓ Direct surgical repair of technically difficult or otherwise inoperable vascular lesions of the brain may become possible or safer using profound hypothermia and circulatory arrest. Most surgeons who use this technique establish extracorporeal circulation by cannulating the femoral vessels. To avoid difficulties associated with this closed chest method, a method was devised to establish extracorporeal circulation, profound hypothermia, and circulatory arrest by direct cannulation of the right atrium and aorta through the chest. This technique is described in a patient whose otherwise inoperable vertebral artery aneurysm was successfully treated. This approach is simple and offers several advantages over the closed chest method.
Treatment of colloid cysts of the third ventricle by stereotaxic microsurgical laser craniotomy
Authors: Abernathey Chad D. , Davis Dudley H. , Kelly Patrick J.
Published: May 2009

✓ The therapeutic strategies employed in the management of anterior third-ventricular mass lesions remain controversial. Resection by conventional craniotomy, whether via a transcallosal or transcortical approach, carries well-known risks and limitations. Alternatively, in this region traditional stereotaxy has been relegated to use with biopsy only or cyst aspiration procedures. Combining aspects of both conventional and stereotaxic techniques has allowed total removal of 12 colloid cysts in six women and six men ranging in age from 25 to 71 years. No mortality and minimal morbidity have been associated with the procedures. There has been no evidence of recurrence in an average follow-up period of 19 months.

By coupling the benefits of stereotaxic precision and localization to the microsurgical management of colloid cysts, several rewards have been realized: 1) only a limited cortical dissection is needed; 2) the hazards of callosal or forniceal injury can be avoided; 3) the lesion is easily localized regardless of ventricular size; 4) hemostasis can be readily achieved with bipolar cautery or defocused laser power; and 5) most importantly, a total resection is possible with little risk to the patient. Stereotaxic microsurgical laser craniotomy provides a new option for the management of colloid cysts and other anterior third-ventricular lesions.
Endoscopic surgery versus medical treatment for spontaneous intracerebral hematoma: a randomized study
Authors: Auer Ludwig M. , Deinsberger Wolfgang , Niederkorn Kurt , Gell Günther , Kleinert Reinhold , Schneider Gerhard , Holzer Peter , Bone Gertraude , Mokry Michael , Körner Eva , Kleinert Gertrude , Hanusch Susanna
Published: May 2009

✓ A controlled randomized study of endoscopic evacuation versus medical treatment was performed in 100 patients with spontaneous supratentorial intracerebral (subcortical, putaminal, and thalamic) hematomas. Patients with aneurysms, arteriovenous malformations, brain tumors, or head injuries were excluded. Criteria for inclusion were as follows: patients' age between 30 and 80 years; a hematoma volume of more than 10 cu cm; the presence of neurological or consciousness impairment; the appropriateness of surgery from a medical and anesthesiological point of view; and the initiation of treatment within 48 hours after hemorrhage. The criteria of randomization were the location, size, and side of the hematoma as well as the patient's age, state of consciousness, and history of hypertension. Evaluation of outcome was performed 6 months after hemorrhage.

Surgical patients with subcortical hematomas showed a significantly lower mortality rate (30%) than their medically treated counterparts (70%, p < 0.05). Moreover, 40% of these patients had a good outcome with no or only a minimal deficit versus 25% in the medically treated group; the difference was statistically significant for operated patients with no postoperative deficit (p < 0.01). Surgical patients with hematomas smaller than 50 cu cm made a significantly better functional recovery than did patients of the medically treated group, but had a comparable mortality rate. By contrast, patients with larger hematomas showed significantly lower mortality rates after operation but had no better functional recovery than the medically treated group. This effect from surgery was limited to patients in a preoperatively alert or somnolent state; stuporous or comatose patients had no better outcome after surgery. The outcome of surgical patients with putaminal or thalamic hemorrhage was no better than for those with medical treatment; however, there was a trend toward better quality of survival and chance of survival in the operated group.
Angiographic frequency of anterior circulation intracranial aneurysms
Authors: Atkinson John L. D. , Sundt Thoralf M. , Houser O. Wayne , Whisnant Jack P.
Published: May 2009

✓ A retrospective angiographic analysis was designed to extrapolate the frequency of angiographically defined asymptomatic intracranial aneurysms in the anterior circulation from a relatively unbiased clinical series. A total of 9295 angiograms were reviewed from January, 1980, to January, 1987, and, based on these, 278 patients with minimal bias for the presence of an aneurysm were selected. Three patients were found to have incidental aneurysms; thus, the angiographic frequency of patients with asymptomatic aneurysms in this series was 1%. This patient population is skewed toward the older age groups and probably over-represents the incidence of these aneurysms in the population at large. Comparing current subarachnoid hemorrhage statistics and the low frequency of asymptomatic aneurysms suggests that a larger percentage of these aneurysms than was previously thought subsequently rupture. This study contrasts sharply with previous reports quoting a high incidence of aneurysms, and significantly alters the concept and treatment of this disease.
Regrowth of aneurysm sacs from residual neck following aneurysm clipping
Authors: Lin Teresa , Fox Allan J. , Drake Charles G.
Published: May 2009

✓ It is recognized that incomplet treatment of an aneurysm may result in recurrent hemorrhage with serious or fatal consequences. For this reason, patients treated at the authors' institution in whom a large portion of the aneurysm neck or sac remained after application of a clip or ligature have been subjected to reoperation. However, 1- to 2-mm residual necks seen in postoperative angiography have been thought to pose little risk. Some cases of aneurysms recurring from a narrow residual neck after clipping have been reported, and a few instances of recurrent aneurysm have been described after apparently complete occlusion of the neck (as observed angiographically or in the surgeon's judgment). In recent years, a surprising number of cases have been presented in which this seemingly unimportant remnant of the neck dilated over a long period to become a dangerous aneurysm. This finding stresses the importance of complete aneurysm occlusion and of postoperative angiography for the recognition of a residual aneurysm neck. This should be important not only in aneurysm clipping but also in the endovascular treatment of intracranial aneurysms with detachable balloons.
Release of glutamate and of free fatty acids in vasogenic brain edema
Authors: Baethmann Alexander , Maier-Hauff Klaus , Schürer Ludwig , Lange Manfred , Guggenbichler Christine , Vogt Wolfgang , Jacob Karl , Kempski Oliver
Published: May 2009

✓ The pathophysiological potential of mediator substances in manifestations of secondary brain damage is attracting increased attention. This is particularly true of the excitatory transmitters glutamate and arachidonic acid. Noxious properties of these compounds in central nervous tissue have been demonstrated. The current study was performed to determine whether glutamate and arachidonate are released in brain tissue secondary to focal trauma. For this purpose, a cold injury of exposed cerebral cortex was induced in cats. Marked accumulation of glutamate was observed in interstitially drained edema fluid, reaching 10 to 15 times the level that was assessed in normal cerebrospinal fluid (CSF) prior to trauma. The extracellular release of glutamate was further dramatically enhanced by a critical decrease of the cerebral perfusion pressure due to a malignant increase of intracranial pressure. Under these conditions, glutamate concentrations 1000 to 1500 times normal levels accumulated in vasogenic edema fluid, demonstrating a relationship between the extent of the release of glutamate in damaged brain and the severity of the insult. Although under normal conditions glutamate concentrations in plasma were considerably higher than in the interstitial fluid, the pronounced increase of glutamate in this compartment due to trauma cannot be explained by transport of the compound together with the plasma-like edema from the intravascular space.

Corresponding findings were obtained for free fatty acid concentrations in edema fluid. Almost all fatty acids that were studied had a significantly higher concentration in edema fluid than in normal CSF obtained as a control prior to trauma. However, contrary to the findings for glutamate, fatty acid concentrations in edema fluid were lower than in plasma. Accumulation of fatty acids in vasogenic edema fluid might, therefore, have resulted from uptake of the material together with edema fluid through the breached blood-brain barrier. Arachidonic acid was an exception. Its concentrations were significantly higher in edema fluid than in plasma, suggesting that it was released from cerebral parenchyma as the underlying mechanism of its extracellular accumulation.

The current observations provide further support for a mediator function of glutamate and arachidonic acid in acute traumatic lesions of the brain. Quantitative assessment of the release of highly active mediator substances in brain tissue may facilitate analysis of the therapeutic efficiency of specific treatment aimed at interfering with the release or pathological function of mediators of secondary brain damage.
CSF production in acute ventriculitis
Authors: Breeze Robert E. , McComb J. Gordon , Hyman Shigeyo , Gilles Floyd H.
Published: May 2009

✓ Clinically, there appears to be a significant reduction in cerebrospinal fluid (CSF) formation during acute ventriculitis — an observation that has not been well documented by experimental studies. To examine this phenomenon, an inoculum of Escherichia coli was injected into the lateral ventricles of New Zealand White rabbits. Approximately 18 hours later, the survivors (64%) underwent a 3-hour ventriculocisternal perfusion of carbon-14-dextran (MW 7 × 104) as a reference marker for CSF formation. On the average, CSF formation in this experimental group was reduced by one-half to two-thirds of normal, confirming the clinical observation. Histologically, the stroma of the choroid plexus was the site of an extensive inflammatory infiltrate. Meningitis, ependymitis, and focal encephalitis completed the picture. Vasculitis was not present in the choroid plexus. The epithelium of the choroid plexus underwent patchy cellular swelling or frank necrosis and destruction.

It is postulated that the changes in the choroid plexus caused by the inflammatory process were responsible for the diminished CSF formation in this acute setting. Reduced choroidal blood flow and/or enterotoxin may play a role in these alterations.
Posterior fossa stereotaxic biopsy using the Brown-Roberts-Wells stereotaxic system
Authors: Guthrie Barton L. , Steinberg Gary K. , Adler John R.
Published: May 2009

✓ Stereotaxic biopsy has been shown to be a reliable means of diagnosing posterior fossa lesions. The authors describe a technique for infratentorial transcerebellar stereotaxic access to posterior fossa parenchymal lesions using the Brown-Roberts-Wells apparatus in its standard commercial configuration. The necessity for tissue diagnosis of these lesions is briefly discussed.
Electrophysiological connections between the hippocampus and entorhinal cortex in patients with complex partial seizures
Authors: Rutecki Paul A. , Grossman Robert G. , Armstrong Dawna , Irish-Loewen Susan
Published: May 2009

✓ The electrophysiological properties of the neural pathways between the hippocampus and the entorhinal cortex were studied intraoperatively in 31 patients undergoing anterior temporal lobectomy for medically intractable complex partial seizures. The hippocampus, removed en bloc, was studied histologically and the pathology was correlated with the electrophysiological findings. In 29 of the patients, entorhinal stimulation evoked a characteristic positive-negative potential in the hippocampus. The entorhinal-evoked hippocampal response closely resembled, or was identical to, the spontaneously occurring hippocampal interictal spike discharge. In patients with Ammon's horn sclerosis in whom there was a major loss of neurons in the hippocampal subfields CA1, CA3, and CA4, the evoked responses were of simple morphology and long latency(mean 21.9 msec to the peak of the first potential). In patients with a ganglioglioma in whom the hippocampus was histologically normal, the evoked responses were of greater complexity and shorter latency (mean 11.8 msec). Stimulation at a single entorhinal site evoked similar waveforms at different hippocampal recording sites. Conversely, stimulation at different entorhinal sites evoked similar responses at a single hippocampal recording site. Stimulation of the hippocampus evoked a potential in the entorhinal cortex and, in some instances, in the amygdala, insula, and lateral temporal cortex. These connections may produce a positive feedback loop that favors seizure generation.
Combination chemotherapy with cisplatin and etoposide for malignant intracranial germ-cell tumors
Authors: Kobayashi Tatsuya , Yoshida Jun , Ishiyama Junzo , Noda Satoshi , Kito Akira , Kida Yoshihisa
Published: May 2009

✓ Antitumor activity against intracranial malignant teratoma by combination chemotherapy with cisplatin and etoposide was evaluated in experimental and clinical studies. A human teratoma cell line (Tera 2) was exposed in vitro to cisplatin and/or etoposide, after which cell growth inhibition and alterations of deoxyribonucleic acid (DNA) histograms were observed. The results indicated that a synergistic cytotoxic effect was achieved by use of both agents in combination. Four cases of recurrent intracranial germ-cell tumor (three malignant teratomas and one germinoma) were treated with cisplatin and etoposide. With this combinationtherapy, regression of the tumor was observed in all four cases (three complete and one partial), for a total response rate of 100%. During a follow-up period of 9 to 22 months, no recurrence or progression has been noted in three of these cases.
The effects of dexamethasone on C6 astrocytoma radiosensitivity
Authors: Lordo Carl D. , Stroude Eric C. , Maestro Rolando F. Del
Published: May 2009

✓ Brain-tumor patients often undergo radiation therapy while receiving corticosteroids for the treatment of cerebral edema. Studies have demonstrated that dexamethasone is radioprotective in a number of cell lines. The C6 astrocytoma cell line is well established in vitro and is modulated by dexamethasone treatment. It has therefore been hypothesized that dexamethasone-treated C6 astrocytoma cells would be more resistant to radiation-induced damage.

The present study was carried out to assess this hypothesis using both the in vitro C6 astrocytoma monolayer and three-dimensional multicellular spheroid models. Dexamethasone was inhibitory to the C6 astrocytoma cells in the monolayer preparation, increasing their doubling time by 13%. In the spheroid cultures, dexamethasone treatment decreased the number of cells per spheroid by 46%. Dexamethasone did not affect the plating efficiency of either the cells from the monolayer experiment or those dissociated from spheroids, however, suggesting that the inhibitory effect was not tumoricidal. At a clinical concentration (1.94 × 10−5 M), dexamethasone did not significantly influence plating efficiency of irradiated C6 astrocytoma cells in monolayer or three-dimensional spheroid cultures.
Absence of collagen deficiency in familial cerebral aneurysms
Authors: Leblanc Richard , Lozano Andrés M. , van der Rest Michel , Guttmann Ronald David
Published: May 2009

✓ It has been suggested that a deficiency in the expression of type III collagen may play a role in the pathogenesis of cerebral aneurysms. To test this hypothesis in cases of familial cerebral aneurysms, fibroblast cell cultures were established and the expression of collagen types I and III was studied in a patient with three cerebral aneurysms whose mother and sister also had cerebral aneurysms. Cultured skin fibroblasts were labeled with tritiated proline. The collagens and procollagens were precipitated and run on sodium dodecyl sulfate-polyacrylamide gel electrophoresis after reduction to analyze procollagen chains. Control cell lines were analyzed simultaneously. Quantitation of the ratios of type III to type I procollagen synthesis was achieved by integration of the intensities of the pro-α1 (III), pro-α1(I), and pro-α2(I) bands on fluorograms of electrophoretic gels of medium proteins.

There was no difference in type I and III procollagen levels observed between the cells from the aneurysm patient and those from the control cell lines. These data do not support the hypothesis that familial cerebral aneurysms are caused by a deficiency of type III collagen.
Prognostic factors for lower respiratory tract infections after brain-tumor surgery
Authors: Dauch Wolfgang A. , Landau Gotthard , Krex Dietmar
Published: May 2009

✓ Nosocomial infection of the lower respiratory tract is a frequent and serious complication after major operations. A 32% incidence of lower respiratory tract infections was found after brain-tumor surgery in 289 patients, with a 21% incidence of pneumonia. In 186 of these patients (Group A), five factors were identified which were associated with an increased risk of postoperative lower respiratory tract infection. These were: age, tumor type, cardiac insufficiency, preoperative disturbances of consciousness, and preoperative corticosteroid treatment. Based on these factors, a risk score was developed which correlated well with the incidence of infection in this group of patients.

In a second group of patients (Group B), the derived risk score was applied and was found to possess a high degree of validity. As long as patients were intubated postoperatively, their freedom from infection decreased exponentially, with a half-life of 3.5 days.
Subtle huge intervertebral disc herniation
Authors: Flak Borys , Li David
Published: May 2009

✓ The accuracy of computerized tomography (CT) in diagnosing herniated discs has been well established. Huge herniated discs, which paradoxically may be very subtle, have been mentioned but not stressed as potential causes of false-negative diagnosis. Five cases during a 5-year period encompassing approximately 2500 examinations have been encountered by the authors. In this experience, the most consistent finding is the subtle increased density of the disc compared with the dural sac. The diagnosis is aided by awareness that huge discs severely compressing the dural sac may be very subtle; the use of narrower windows for CT scanning, sagittal re-formation, and occasionally the use of myelography with or without repeat CT scanning may also assist.
Posterior cervical interspinous compression wiring and fusion for mid to low cervical spinal injuries
Authors: Benzel Edward C. , Kesterson Lee
Published: May 2009

✓ A technique of posterior cervical interspinous compression wiring and fusion, which offers significant immediate stability, is presented. Its efficacy in 50 consecutive cases illustrates its utility. The technique involves the passage of an interspinous cerclage wire. Rather than placement of onlay laminar and facet grafts, a split-thickness tricortical iliac-crest graft is compressed against the involved medial laminae and spinous processes bilaterally. These grafts are held in place by a compression wire, which encircles the grafts and thus sandwiches the spinous processes between them. This virtually ensures subsequent bone fusion and offers substantial acute stability. The compression wire offers an added advantage of encircling the cerclage wire, thus pulling it dorsally. This significantly diminishes translational mobility at the unstable segment. It also minimizes hyperextension at the unstable segment via medial compression of the grafts into the interspinous space.

The fusion of a minimal number of spinal segments is emphasized. This substantially diminishes the chance of flexible kyphosis and degenerative changes, both above and below the fusion site. A three- or four-level fusion was performed in only 11 patients. The remaining 39 patients underwent two-level fusion. A solid bone fusion was achieved in all cases, with a follow-up period of at least 6 months. In one patient, the spinous process fractured, necessitating an anterior fusion procedure. The technique presented here appears to acutely offer a very stable construct and, in addition, is a simple and straightforward procedure for the treatment of the unstable cervical spine.
Xenogeneic pericardium as a dural substitute in reconstruction of suboccipital dura mater in children
Authors: Pařízek Jan , Měřička Pavel , Špaček Josef , Němeček Stanislav , Eliáš Pavel , Šercl Miroslav
Published: May 2009

✓ A 5-year experience with the glutaraldehyde-stabilized freeze-dried radiation-sterilized calf pericardium used as a dural substitute is reported. The structure of pericardium xenograft is compared with other collagenous materials used for duraplasty (allogeneic fascia lata and dura mater) by light and electron microscopy. The special neurosurgical techniques involved in using pericardium xenografts in the reconstruction of suboccipital dura mater in children are presented in detail.
Proto-oncogene analyses in brain tumors
Authors: Fujimoto Masahito , Sheridan Peter J. , Sharp Z. Dave , Weaker Frank J. , Kagan-Hallet Kathleen S. , Story Jim L.
Published: May 2009

✓ The present study determined which oncogenes (N-myc, c-myc, v-sis, or v-fos) were amplified and which messenger ribonucleic acids (mRNA's) accumulated in 10 primary human brain tumors of neuroectodermal origin. The tumors included four glioblastomas multiforme, one mixed glioma (astrocytoma grade I and ependymoma), one astrocytoma grade II, one cystic cerebellar astrocytoma, one ependymoma, one ganglioglioma, and one medulloblastoma. The relative amounts of polyadenylated (poly(A)+) RNA's homologous to these genes and their copy number were determined using the RNA and deoxyribonucleic acid blot hybridization techniques. The N-myc and v-sis probes hybridized strongly to the poly(A)+ RNA from the same recurrent glioblastoma with gene amplifications (N-myc 80 copies; v-sis three to four copies). The c-myc probe hybridized strongly to the recurrent medulloblastoma without gene amplification. The amplification or abundant accumulation of mRNA's homologous to their oncogenes may be involved in tumorigenesis or the aggressiveness of these malignant brain tumors of neuroectodermal origin and may be good molecular indicators of an extremely malignant state in these tumors.
Epidermal growth factor receptor in human glioma
Authors: Arita Norio , Hayakawa Toru , Izumoto Shuuichi , Taki Takuyu , Ohnishi Takanori , Yamamoto Hiroshi , Bitoh Shoji , Mogami Heitaro
Published: May 2009

✓ Distribution of the epidermal growth factor (EGF) receptor in the surgical specimen of the human glioma was studied by immunohistochemical techniques using a monoclonal anti-EGF receptor antibody. Of 11 gliomas examined, EGF receptors were detected in nine glioblastomas and in one fibrillary astrocytoma. In the majority of cells, staining was observed over the cell membrane. Nuclear and cytoplasmic staining was also seen. In four glioblastomas, EGF receptor-positive cells were diffusely distributed in the tumor tissue. In one glioblastoma and one fibrillary astrocytoma, only a few positive cells were observed. These results imply the possible role of EGF receptors in the cellular proliferation of the human glioma.
Laboratory performance of single-piece ventriculoperitoneal shunts with distal slit-valve control
Authors: Sparrow Owen Charles
Published: May 2009

✓ Three different types of single-piece ventriculoperitoneal shunts with distal slit-valve control (Codman Unishunt, Codman Unishunt with chambers, and Heyer-Schulte one-piece shunt) in their low- and medium-pressure forms were assessed in the laboratory by both static and dynamic tests. A statistical analysis of variance showed large differences in performance which were not confined to the different pressure ranges as may have been expected. Substantial variation occurred between nominally identical shunts and between identically rated shunts of different makes. Guidelines for an industry standard are proposed.
The significance of thrombocytopenia in the development of postoperative intracranial hematoma
Authors: Chan Kwan-Hon , Mann Kirpal S. , Chan T. K.
Published: May 2009

✓ A group of 35 patients undergoing intracranial surgery who exhibited perioperative thrombocytopenia (platelet count < 150,000/µl) was studied retrospectively. Of the 35 patients, 14 (40%) developed postoperative intracranial hematomas requiring reoperation and seven (20%) died within 2 weeks after the operation. Analysis revealed that a perioperative platelet count below 100,000/µl in a patient who failed to respond to platelet transfusions was associated with a higher risk of postoperative hematoma formation. All six patients with this profile developed postoperative hematomas. If the platelet count rose promptly from below 100,000/µl to a normal level after platelet transfusions, the incidence of hematoma formation decreased dramatically. None of the three patients with this response developed postoperative hematoma. In patients in whom an acute drop in platelet count from the normal range to between 100,000 and 124,000/µl occurred in the immediate perioperative period, there was a significantly higher chance of hematoma formation; this finding has not hitherto been described. Of the 14 patients with this clinical course, eight developed postoperative hematoma after craniotomy for tumors and vascular lesions. This latter observation was substantiated by the fact that thrombocytopenic patients with postoperative hematomas had a greater reduction in platelet count than thrombocytopenic patients with no postoperative hematomas (p = 0.0004).