bluuebunny/crossref_metadata_2025 huggingface dataset:
Interstitial hyperthermia and iridium brachytherapy in treatment of malignant glioma
Authors: Roberts David W. , Coughlin Christopher T. , Wong Terence Z. , Fratkin Jonathan D. , Douple Evan B. , Strohbehn John W.
Published: May 2009

✓ An oncolytic effect of hyperthermia in the 42° to 43°C range has been previously demonstrated in cell culture and animal models. To apply this modality clinically, an interstitial microwave antenna array system has been developed for the delivery of controlled hyperthermia to an intracranial tumor volume, and a Phase I clinical trial involving six patients with malignant gliomas was undertaken. The protocol to study technical feasibility and patient tolerance combined interstitial iridium-192 irradiation and interstitial hyperthermia with 60-minute hyperthermia sessions immediately before and after brachytherapy. After-loading catheters suitable for both treatment modalities were implanted using a computerized tomography-assisted technique. Thermometry data confirmed the ability of a microwave antenna system to achieve reliable temperature distributions, and reasonable patient tolerance was documented.
The proliferative potential of human pituitary tumors in situ
Authors: Nagashima Tadashi , Murovic Judith A. , Hoshino Takao , Wilson Charles B. , DeArmond Stephen J.
Published: May 2009

✓ At the start of transsphenoidal microsurgery for removal of various types of pituitary adenomas, 21 patients received a 1-hour intravenous infusion of 5-bromodeoxyuridine (BUdR, 200 mg/sq m) to label tumor cells in the deoxyribonucleic acid (DNA) synthesis phase (S-phase). Excised tumor specimens were fixed in 70% ethanol and stained by the indirect peroxidase method using anti-BUdR monoclonal antibody as the first antibody. The percentage of BUdR-labeled cells, or S-phase fraction, was calculated for each specimen. The S-phase fraction was less than 0.1% in nine cases, 0.1% to 0.5% in seven, and greater than 0.5% in five. Except in two cases of Nelson's syndrome, in which it was greater than 1%, the S-phase fraction did not correlate with any other variable, including patient age, tumor size, or the duration of signs and symptoms.

The small S-phase fraction of most of the pituitary adenomas correlates well with the clinical behavior of these tumors, which grow much more slowly than other kinds of brain tumors such as gliomas. However, the S-phase fractions varied by as much as one order of magnitude. The higher S-phase fractions may reflect aggressive and invasive growth. These results indicate that immunohistochemical studies of cell kinetics using BUdR and anti-BUdR monoclonal antibodies may provide information about the biological characteristics of pituitary adenomas which could lead to the design of appropriate treatment regimens (including surgery, radiation therapy, and chemotherapy) for individual patients.
Effects of hypertonic saline versus lactated Ringer's solution on cerebral oxygen transport during resuscitation from hemorrhagic shock
Authors: Prough Donald S. , Johnson J. Carson , Stump David A. , Stullken Edward H. , Poole Galen V. , Howard George
Published: May 2009

✓ Hypertonic saline successfully restores systemic hemodynamics in dogs and humans with severe hemorrhagic shock and, in contrast to lactated Ringer's solution, does not increase intracranial pressure (ICP). This study compares cerebral oxygen delivery in 12 dogs subjected to hemorrhagic shock by the rapid removal of blood (mean arterial pressure of 40 mm Hg maintained for 30 minutes), and then resuscitated with lactated Ringer's solution (six dogs) or 7.5% saline solution (six dogs) to restore systolic arterial pressure. Both solutions effectively restored systemic hemodynamic stability, increasing cardiac output and systolic blood pressure while decreasing mean and diastolic arterial pressure and systemic vascular resistance. The ICP was significantly lower after resuscitation in the hypertonic saline group (p < 0.05), but cerebral blood flow, which had decreased during shock, was not restored by either fluid, and cerebral oxygen transport fell further secondary to a hemodilutional reduction of hemoglobin. Although hypertonic saline may improve systemic hemodynamics and maintain a low ICP during resuscitation, it fails, as does Ringer's solution, to restore cerebral oxygen transport to prehemorrhagic shock levels.
Vasculature to the germinal matrix in rabbit pups
Authors: Fischer Edwin G. , Lorenzo Antonio V. , Landis William J. , Welch Keasley , Ofori-Kwakye Stephen K. , Dorval Brent , Hodgens Karen J. , Kerr Clare S.
Published: May 2009

✓ The authors report a study of the cerebral vasculature of premature rabbits pertaining to the germinal matrix (GM). A pigmented silicone material (Microfil) was injected into the carotid artery of anesthetized rabbits. Methyl methacrylate vascular casts of a similar group of premature rabbits were examined by scanning electron microscopy. The GM is supplied by arteries from both the basal and convexity surfaces of the brain. Vessels could be identified as arteries or veins by their typical patterns of branching and by the characteristic impressions made on the methyl methacrylate casts by endothelial nuclei. Specific evidence of structural weaknesses in the vasculature, which could be a site of predilection for GM bleeding, was not observed. The similarities in basal ganglia vasculature between premature rabbits and humans justifies using the rabbit model to study vascular aspects of the GM and intraventricular hemorrhage.
Distal posterior cerebral artery aneurysm
Authors: Simpson Richard K. , Parker Warren D.
Published: May 2009

✓ A case of an unusual distal posterior cerebral artery (PCA) aneurysm is presented. The saccular aneurysm arose from a fetal PCA distal to the posterior temporal branch of the P3 segment. The aneurysm was treated by placing a clip on the PCA distal to the anterior temporal branch of the P2 segment. A ventriculoperitoneal shunt was also placed. The patient's postoperative recovery was unremarkable and without residual neurological deficit. The highly unusual location of this aneurysm is discussed and the neurosurgical literature is reviewed in detail.
Delayed intracerebral hematoma at the site of a subarachnoid bolt pressure monitor
Authors: Bobo Hunt , Miller Jimmy D. , Evans Owen B. , Kapp John P.
Published: May 2009

✓ The authors report development of a delayed intracerebral hematoma following use of a subarachnoid bolt for intracranial pressure monitoring. This complication has not been previously reported.
Cerebrospinal fluid rhinorrhea following surgery for acoustic neurinoma
Authors: Gordon Derek S. , Kerr Alan G.
Published: May 2009

✓ In a series of 48 patients with acoustic neurinoma removed by the suboccipital route, one patient developed cerebrospinal fluid rhinorrhea and another patient had delayed-onset meningitis. Each complication was attributed to opening the posteromedial air-cell tract in the posterior wall of the internal auditory meatus. In operations requiring removal of the posterior meatal wall, it is important to look for the air-cell tract which may not be apparent on computerized tomography. If the tract is opened the cells should be occluded by bone wax.
Long-term results in transsphenoidal removal of nonfunctioning pituitary adenomas
Authors: Ebersold Michael J. , Quast Lynn M. , Laws Edward R. , Scheithauer Berndt , Randall Raymond V.
Published: May 2009

✓ Little has been written about the long-term results of transsphenoidal treatment for clinically nonfunctioning pituitary adenomas. The records of 100 patients who had undergone a transsphenoidal procedure for excision of such tumors were reviewed. Immunocytology for pituitary hormones was performed in all cases. The group consisted predominantly of null-cell adenomas, although a small number of prolactinomas and gonadotropic tumors were found. The mean diameter of the tumors at the time of detection was slightly more than 2 cm. In most cases, the presenting symptoms were due to the mass effect of the tumor (that is, visual symptoms in 72 patients, hypopituitarism in 61, headache in 36, and cranial nerve disturbance other than visual loss in 10). Radiation therapy was recommended for patients in whom subtotal removal of the adenoma was expected. Six patients developed symptomatic tumor recurrence, and 10 patients demonstrated radiographic recurrence during the 48 to 100 months (mean 73.4 months) of follow-up observation. Only three of 10 deaths during the follow-up period were due to pituitary disease or treatment.
Intracranial cavernous angioma: presentation and management
Authors: Tagle Patricio , Huete Isidro , Méndez Jorge , del Villar Sergio
Published: May 2009

✓ Thirteen cases of cerebral cavernous angiomas are reported, and their radiological and pathological features are reviewed. The clinical presentation was variable: 53.8% of patients had seizures, 30.8% intracerebral hemorrhage, and 15.4% focal neurological signs, including one unusual case that presented as a cerebellopontine angle tumor. The computerized tomography (CT) scans were abnormal in all cases. Angiography was positive only when there was mass effect due to associated hematoma. Surgery was performed in 12 cases with good results. The prognosis of the 13 cases was favorable, with no mortality in this series. These data suggest that the combination of a recent seizure disorder with a hyperdense intracerebral nodule on the CT scanning should alert the neurosurgeon to the possibility of a cavernous angioma.
The transtorcular embolization of vein of Galen aneurysms
Authors: Mickle J. Parker , Quisling Ronald G.
Published: May 2009

✓ Vein of Galen malformations are a diverse group of deeply located high-flow vascular lesions that are difficult to eradicate with standard surgical techniques. New nonsurgical interventional techniques offer encouraging results as alternative therapeutic choices in these complicated vascular shunts. Use of a new procedure of transtorcular embolization with Gianturco embolic coils is described in three patients harboring vein of Galen aneurysms. Two of the three patients had a satisfactory outcome. This technique is simple and quick, and can produce progressive thrombosis in these high-flow vascular fistulas.
The effect of mannitol on cerebral blood flow
Authors: Jafar Jafar J. , Johns Lydia M. , Mullan Sean F.
Published: May 2009

✓ The objective of this study was to evaluate the effects of mannitol, given over different time periods, on regional cerebral blood flow (rCBF) in patients with intracranial aneurysms. Seven patients with unruptured aneurysms (Group I) and 16 patients with Grade I and II subarachnoid hemorrhage (SAH) (Group II) received 1.5 gm/kg/8 hrs of 20% mannitol intravenously over a 24-hour period. Seven other patients with unruptured aneurysms (Group III) received 1.5 gm/kg of mannitol over 8 hours only. The last seven patients with unruptured aneurysms (Group IV) received the same dose, but as an intravenous bolus. Over a period of 24 hours, the patients underwent serial measurements of rCBF, intracranial pressure (ICP), mean blood pressure (MBP), cardiac output, and cerebral metabolic rate of oxygen consumption (CMRO2). Mannitol, when given as a continuous intravenous infusion, increased rCBF significantly without increasing MBP or decreasing ICP. This increase was more pronounced in SAH patients. The effects of mannitol lasted for 18 hours when given over an 8-hour period only; however, when it was given as a bolus, the increase in rCBF lasted for 24 hours, cardiac output tended to increase, and the effect on CMRO2 was variable.
Effect of naloxone on cerebral perfusion and cardiac performance during experimental cerebral ischemia
Authors: Hariri Robert J. , Supra Elizabeth L. , Roberts John Paul , Lavyne Michael H.
Published: May 2009

✓ Transient global cerebral ischemia (TGI) was induced in awake rats using the “four-vessel” occlusion model of Pulsinelli and Brierley. Blood pressure, arterial blood gases, cerebral blood flow, and cardiac output were measured during the acute (up to 2 hours) and chronic (2 to 72 hours) postischemic time periods. Coincident with the onset of TGI, cardiac output and caudate blood flow were depressed. The former returned to baseline within 30 minutes after the conclusion of TGI, and the latter progressed to hyperemia at 12 hours (81.8 ± 4.9 vs 68.6 ± 3.9 ml/min/100 gm tissue (mean ± standard error of the mean)) and oligemia at 72 hours (45.5 ± 4.8 ml/min/100 gm tissue) post-TGI in the untreated control rats. Arterial blood gases and blood pressure were unchanged. Naloxone (1 mg/kg) given at the time of TGI or as late as 60 minutes post-TGI and every 2 hours thereafter for 24 hours or bilateral cervical vagotomy prevented the depression in cardiac output and blocked the hyperemic-oligemic cerebral blood flow pattern that was predictive of stroke in this rat model.

Changes in cardiac output after TGI in this model appear to be mediated by parasympathetic pathways to the heart from the brain stem. Opiate receptor blockade probably blocks endogenous opioid peptide stimulation of these brain-stem circulatory centers, which results in inhibition of parasympathetic activity and improvement in cardiac output. The usefulness of naloxone in the treatment of experimental stroke may be a function of its ability to improve cerebral perfusion in pressure-passive cerebrovascular territories. Variations in cardiac output during experimental stroke may explain the dissimilar responses to naloxone treatment reported by other investigators of experimental stroke.
Nuclear magnetic resonance imaging and spectroscopy in experimental brain edema in a rat model
Authors: Bederson Joshua B. , Bartkowski Henry M. , Moon Kirkland , Halks-Miller Meredith , Nishimura Merry C. , Brant-Zawadski Michael , Pitts Lawrence H.
Published: May 2009

✓ Many aspects of the use of high-resolution nuclear magnetic resonance (NMR) imaging in the examination of brain edema have not been fully explored. These include the quantitation of edema fluid, the ability to distinguish between various types of edema, and the extent to which tissue changes other than a change in water content can affect NMR relaxation times. The authors have compared NMR relaxation times obtained by both in vivo magnetic resonance imaging (MRI) and in vitro NMR spectroscopy of brain-tissue samples from young adult rats with cold lesions, fluid-percussion injury, hypoxic-ischemic injury, bacterial cerebritis, and cerebral tumor. Changes in relaxation times were compared with changes in brain water content, cerebral blood volume, and the results of histological examination.

In general, both in vivo and in vitro longitudinal relaxation times (T1) and transverse relaxation times (T2) were prolonged in the injured hemispheres of all experimental groups. Water content of tissue from the injured hemispheres was increased in all groups. A linear correlation between T2 (but not T1) and water content was found. Changes in the values of T1 and T2 could be used to distinguish tumor from cold-injured tissue. Cerebral blood volume was reduced in the injured hemispheres and correlated inversely with prolongation of T1 and T2. The results of this study suggest that, in a clinical setting, prolongation of T2 is a better indicator of increased water content than prolongation of T1, yet quantitation of cerebral edema based solely upon prolongation of in vivo or in vitro T1 and T2 should be undertaken with caution.
Suprascapular nerve entrapment
Authors: Hadley Mark N. , Sonntag Volker K. H. , Pittman Hal W.
Published: May 2009

✓ The suprascapular nerve, formed from the upper trunk of the brachial plexus, can be entrapped at the suprascapular notch and result in significant patient morbidity. Seven patients with suprascapular nerve palsy are presented, and their evaluation, treatment, and outcome over a mean follow-up period of 24 months are described. Six of these patients were treated surgically and one medically; all experienced good results. In a review of the relevant literature, this entity is distinguished from other causes of shoulder pain, the typical presenting signs and symptoms are outlined, and the appropriate management of these patients is addressed.
Arteriovenous malformations of the posterior fossa
Authors: Batjer Hunt , Samson Duke
Published: May 2009

✓ Infratentorial arteriovenous malformations (AVM's) represent only 5% to 1% of all AVM's in major series. Since 1977, 32 patients with intracranial intradural malformations of the brain stem or cerebellum have been evaluated at the University of Texas Health Science Center, 30 of whom underwent surgical treatment. Twenty-three patients presented with intracranial hemorrhage, which was recurrent in 11 cases, and nine patients were evaluated for progressive brain-stem or cerebellar deficits. A history of progressive deficits was unusual in the group that presented with hemorrhage, and a prior or subsequent hemorrhage was rare in the patients initially evaluted for progressive deficits. Seventeen of these AVM's were located in the vermis, seven within the cerebellar hemisphere, two in the tonsil, two in the cerebellopontine angle, and four within the brain stem. Operative intervention was directed at primary resection in 15 cases, staged resection in seven, embolization and resection in five, and evacuation of hematoma in three. Operative mortality in this surgical series was 7%, with significant morbidity in 13%. Use of modern microsurgical techniques in removal of posterior fossa AVM's may offer results better than the natural history of the disease process, especially in patients who present with hemorrhage.
Management of arteriovenous malformations of the brain stem
Authors: Solomon Robert A. , Stein Bennett M.
Published: May 2009

✓ In a series of 250 intracranial arteriovenous malformations (AVM's), 12 malformations involved the brain stem. Nine of these lesions were treated surgically, with complete obliteration in eight. There were no operative deaths, and only two patients were made worse by surgery. In the nonsurgically treated group, one patient had embolization therapy and two patients underwent radiation therapy. Results in these three patients have not been satisfactory. These data indicate that brain-stem AVM's can be surgically removed with acceptable morbidity.
Stereotaxic surgery with a magnetic resonance- and computerized tomography-compatible system
Authors: Lunsford L. Dade , Martinez A. Julio , Latchaw Richard E.
Published: May 2009

✓ Modern stereotaxic surgery is dependent upon compatible advanced imaging tools, including computerized tomography (CT) scanning and magnetic resonance (MR) imaging. The authors describe three cases in which the patients underwent stereotaxic surgery for mass lesions identified by both MR imaging and CT scans. Identical target coordinates were defined by both techniques, and accuracy was confirmed by intraoperative CT. In comparison to stereotaxic CT, MR provided superior contrast resolution, allowed direct multiplanar imaging and target determination, and permitted accurate correlation of the image with histological features. The operative set-up and technique are described. Stereotaxic surgery with MR imaging may permit more accurate histopathological definition of tumor margins and ultimately lead to better dosimetry for therapeutic procedures such as interstitial brachytherapy.
Continuous intrathecal hydromorphone and clonidine for intractable cancer pain
Authors: Coombs Dennis W. , Saunders Richard L. , Fratkin Jonathan D. , Jensen Lawrence E. , Murphy Carol A.
Published: May 2009

✓ The use of hydromorphone and clonidine, delivered intrathecally by an implanted infusion pump, is described in a patient with intractable cancer pain. The patient was a 48-year-old woman with uterine cervical cancer-related pain that was poorly responsive to conventional oral narcotics. Hydromorphone was used because of the patient's history of morphine intolerance. When progressive intrathecal hydromorphone dosages were required, intrathecal clonidine (an alpha2 adrenergic agonist) was infused concomitantly. Intrathecal hydromorphone and clonidine successfully controlled this patient's pain without the necessity to resort to destructive neurosurgery.
Assessment of nutritional requirements of head-injured patients
Authors: Clifton Guy L. , Robertson Claudia S. , Choi Sung C.
Published: May 2009

✓ A nomogram is presented for estimation of energy expenditure at the bedside in comatose patients during the first 2 weeks after brain injury. In analysis of 312 days of energy expenditure in 57 patients, a combination of Glasgow Coma Scale (GCS) score, heart rate (HR), and days since injury (DSI) was found with multiple regression analysis to provide good prediction of resting metabolic expenditure (RME) according to the following relationship: %RME = 152 − 14(GCS score) + 0.4(HR) + 7(DSI) (n = 111, r = 0.7, p < 0.001). In non-comatose patients, predictive ability was less strong due to inability to measure truly rested values, but HR and GCS score could be used to predict energy expenditure by this relationship: %RME = 90 − 3 (GCS score) + 0.9 (HR) (n = 135, r = 0.47, p < 0.001). In six patients, paralysis was found to decrease energy expenditure to between 100% and 125% of expected. Movement or stimulation had little effect on energy expenditure in patients who could localize stimuli but increased rested values by 20% in posturing patients.

Analysis of fasted balance periods of nitrogen excretion in 22 patients based on 273 days of measurement showed a significant relationship between creatinine-height index (an index of muscle mass) and nitrogen excretion, but no relationship between nitrogen excretion and weight, temperature, and RME. Levels of retention of nitrogen with feeding could not be predicted by any of these variables. Feeding of the individual comatose patient is best guided at present by estimation of energy expenditure using a nomogram and periodic measurement of urinary nitrogen excretion.
Risk factors for postoperative neurosurgical wound infection
Authors: Mollman H. Dennis , Haines Stephen J.
Published: May 2009

✓ A case-control analysis was performed to evaluate the association of 15 potential risk factors with postoperative infection in neurosurgical patients. All infections that developed postoperatively on the neurosurgical service at the University of Minnesota from January, 1970, to March, 1984, were identified. Among the 9202 operations performed during that time, 101 infections occurred for a rate of 1.1%. Three risk factors showed significant association with postoperative infection: cerebrospinal fluid (CSF) leak, concurrent non-central nervous system (CNS) infection, and perioperative antibiotic therapy. The presence of a CSF leak and a concurrent non-CNS infection increased the estimated relative risk of infection to 13:1 and 6:1, respectively. The use of perioperative antibiotics was associated with a decrease in the risk of infection to approximately 20% of the control level. Three other risk factors (paranasal sinus entry, placement of a foreign body, and use of a postoperative drain) appeared to be associated with increased risk of infection, although statistical significance was not demonstrated. None of the remaining nine risk factors studied showed any suggestion of increased risk of infection.
Cerebral effects of hypocapnia plus nitroglycerin-induced hypotension in dogs
Authors: Artru Alan A. , Wright Kim , Colley Peter S.
Published: May 2009

✓ This study examined the effect of hypocapnia (PaCO2 20 mm Hg) on cerebral metabolism and the electroencephalogram (EEG) findings in 12 dogs during nitroglycerin (NTG)-induced hypotension. Previous studies suggest that NTG is a more potent cerebral vasodilator than sodium nitroprusside or trimethaphan. It was speculated that combining hypocapnia with NTG-induced hypotension would cause less disturbance of cerebral metabolism and the EEG than the disturbances previously reported when hypocapnia was combined with hypotension induced by sodium nitroprusside or trimethaphan.

All 12 dogs were examined at 1) normocapnia with normotension; 2) hypocapnia with normotension; and 3) hypocapnia combined with NTG-induced hypotension to mean arterial blood pressure (MABP) levels of 60, 50, and 40 mm Hg. In six dogs the cerebral metabolic rate of oxygen was determined, and the EEG was evaluated using compressed spectral analysis. Brain tissue metabolites were calculated in the other six dogs. During normotension, hypocapnia caused no deterioration of cerebral metabolism or of the EEG. Hypocapnia combined with NTG-induced hypotension caused a decrease of the power of the α and β2 spectra of the EEG at MABP's of 60 mm Hg or less. At an MABP of 40 mm Hg, brain tissue phosphocreatine and the cerebral energy charge decreased, while the brain tissue lactate:pyruvate ratio increased. Thirty minutes after restoration of normocapnia with normotension, cerebral metabolites returned to initial values, but the power of the EEG α and β2 spectra was decreased compared to baseline values.

The cerebral metabolic disturbances and EEG alterations seen here with hypocapnia plus NTG-induced hypotension were similar to those previously reported with hypocapnia plus sodium nitroprusside-induced hypotension, and less than those previously reported with hypocapnia plus trimethaphan-induced hypotension. For hyperventilated patients, administration of NTG may be a better hypotensive treatment than trimethaphan, but similar in effect to sodium nitroprusside.
Reaction of rabbit lateral periventricular tissue to shunt tubing implants
Authors: Del Bigio Marc R. , Bruni J. Edward
Published: May 2009

✓ The reaction of the periventricular tissue of the lateral ventricle to silicone rubber shunt tubing was studied by scanning and transmission electron microscopy. Nonfunctioning shunt tubing was implanted bilaterally into the frontal horns of rabbits, which were then sacrificed at postoperative intervals of 3 days to 16 weeks. Colchicine was used to study mitotic activity at the 3-day to 4-week postimplantation intervals. Reactive changes that occurred in the periventricular tissue correlated with the degree of contact with the implant and also with the duration of the postoperative period. Ependymal cells underwent progressive attenuation and sloughed completely in the most severely affected areas. Prominent gliosis in the subependyma accompanied the ependymal changes. The ventricular surface directly adjacent to holes in the implant developed ependyma-covered glial evaginations which grew into the implant holes beginning 1 week postimplantation. In the region of the outgrowths, ependymal mitotic activity was significantly increased at 1 and 2 weeks postimplantation, and astroglial mitotic activity was increased at 3 days and 1 week. Proliferation of ependymal and glial cells in the area touching the shunt tubing and mechanical factors contributed to the development of cellular outgrowths which may be a factor in the pathogenesis of shunt obstruction in human hydrocephalus.
Radiological and pathological aspects of dural arteriovenous fistulas
Authors: Graeb Douglas A. , Dolman Clarisse L.
Published: May 2009

✓ A case of dural arteriovenous (AV) fistula is presented with detailed radiological and pathological findings. The complex hemodynamic alterations that may result from dural AV fistulas are described. Pathological examination in this case demonstrated widespread occlusion of the superior sagittal sinus with multiple abnormal fistulous communications between abnormal arteries and arterialized veins. A portion of the lesion resembled a recanalized blood clot, in support of the theory proposed by others that dural AV fistulas are acquired lesions.
Primary leptomeningeal ependymoblastoma
Authors: Wada Chieki , Kurata Akira , Hirose Ryuichi , Tazaki Yoshiaki , Kan Shinichi , Ishihara Yoshihiro , Kameya Toru
Published: May 2009

✓ Ependymoblastoma is considered to be a primitive malignant glioma with ependymal differentiation. This rare tumor occurs in very early life and shows rapid growth and a diffuse infiltration through the leptomeningeal space. The tumor cells are highly immature, with numerous mitoses and multilayered ependymal rosettes. The ependymoblastoma described in this report was found in a 17-year-old girl. In spite of detailed clinical and postmortem examinations, no definite primary site was identified in the neuraxis. The lesion spread predominantly throughout the leptomeningeal space. Histological analysis strongly suggested that this tumor originated from a heterotopic glial nest in the subarachnoid space. The absence of immunohistochemical neural tissue markers, glial fibrillary acidic protein, S-100 protein, neuron-specific enolase, and neurofilaments ruled out neuronal or glial differentiation. The authors were unable to find any previous report of primary leptomeningeal ependymoblastoma.
Large intramedullary lipoma of the cervical cord and posterior fossa
Authors: Mori Koreaki , Kamimura Yoshihiko , Uchida Yasufumi , Kurisaka Masahiro , Eguchi Sueo
Published: May 2009

✓ A large intramedullary lipoma of the cervical cord extending into the posterior fossa is reported in a 7-year-old boy. Magnetic resonance imaging was very useful for delineation of the anatomy of the lipoma as an aid in planning the operation.
Analysis of 76 civilian craniocerebral gunshot wounds
Authors: Clark W. Craig , Muhlbauer Michael S. , Watridge Clarence B. , Ray Morris W.
Published: May 2009

✓ A retrospective analysis of 76 civilian craniocerebral gunshot wounds treated over a 20-month period is presented. The authors report a 62% mortality rate and conclude that the admission Glasgow Coma Scale (GCS) score is a valuable prognosticator of outcome. Other important findings were: 1) patients with a GCS score of 3 invariably died, with or without surgical intervention; and 2) the presence of intracranial hematomas, ventricular injury, or bihemispheric wounding was associated with a poor outcome. Standardized methods of data reporting should be adopted in order to allow multicenter trials or comparisons that might lead to management practices that could improve results.
Clinical course and outcome of severe head injury in Australia
Authors: Lyle David M. , Pierce John P. , Freeman Edward A. , Bartrop Roger , Dorsch Nicholas W. C. , Fearnside Michael R. , Rushworth Robin G. , Grant John M. F.
Published: May 2009

✓ The records of 159 severely head-injured patients (all in coma for longer than 6 hours) from Sydney, Australia, were studied. The clinical course, charted over a 2-week period, indicated that 60% of deaths occur by Day 3 and that 12% of patients remain in coma (Glagow Coma Scale (GCS) score < 7) for more than 2 weeks. Overall, at long-term follow-up review more than 2 years after injury, 51% of patients were dead, 7% were severely disabled or vegetative, and 42% had a good to moderate recovery. Outcome of the patients in prolonged coma was assessed separately, with only one-third making a good or moderate recovery; two-thirds of the severely disabled patients came from this group. The high proportion of poor outcomes associated with prolonged coma suggests that this group of patients should be specifically targeted in research. One appropriate intervention with this group would be the restructuring and intensification of early rehabilitation. However, the GCS score lacks the precision needed for this type of study, and a better measure of recovery should be developed.
The effect of mannitol on cerebral white matter water content
Authors: Nath Fred , Galbraith Sam
Published: May 2009

✓ The authors have studied the effect of a low-dose (0.28 gm/kg) bolus infusion of mannitol on brain water in man. In eight patients with severe head injury, small pieces of subcortical white matter were taken at craniotomy both before and after infusion of mannitol. The tissue specific gravity was measured using a graduated specific-gravity column, and from it the brain water content was calculated. White matter specific gravity rose from a mean (± standard error of the mean) of 1.0325 ± 0.0012 before mannitol infusion to 1.0352 ± 0.0011 after mannitol administration, and the brain water content fell from a mean of 80.94% ± 2.5% to 75.28% ± 2.3%. The differences were significant (p < 0.01). This study shows that, after head injury in man, mannitol increases the white matter specific gravity and probably does so by reducing brain water.
Transcranial surgical approaches to the orbital part of the optic nerve: an anatomical study
Authors: Blinkov Samuil M. , Gabibov Gabib A. , Tcherekayev Vassiliy A.
Published: May 2009

✓ The authors have identified and described three transcranial approaches to the intraorbital portion of the optic nerve. The structures encountered in these approaches are demonstrated under magnification in cadavers, and the exposure of the optic nerve is discussed.
Microsurgical endarterectomy under barbiturate protection: a prospective study
Authors: Spetzler Robert F. , Martin Neil , Hadley Mark N. , Thompson Richard A. , Wilkinson Elizabeth , Raudzens Peter A.
Published: May 2009

✓ Carotid endarterectomy has the potential to improve on the natural history of untreated carotid artery disease with respect to subsequent infarction in symptomatic patients with causative angiographic lesions. This benefit of a reduced risk of stroke can be realized only if the perioperative morbidity and mortality rates are kept low. An approach to symptomatic carotid artery bifurcation disease is outlined, with a defined protocol of microsurgical endarterectomy utilizing barbiturate protection during the period of potential focal temporary cerebral ischemia. This protocol includes preoperative antiplatelet therapy, barbiturate anesthesia, the avoidance of an internal shunt, the use of the operating microscope, and strict control of postoperative hypertension. A series of 200 consecutive endarterectomies performed within this protocol in 180 patients and the resultant combined permanent morbidity and mortality rate of 1.5% are reported.
Intracranial pressure, cerebral blood flow, and cerebrospinal fluid formation during hyperammonemia in cat
Authors: Chodobski Adam , Szmydynger-Chodobska Joanna , Urbańska Anna , Szczepańska-Sadowska Ewa
Published: May 2009

✓ Intracranial pressure (ICP), cerebral blood flow (CBF), and the cerebrospinal fluid (CSF) formation rate were examined in anesthetized cats during ammonia intoxication. Hyperammonemia, evoked by intravenous infusion of ammonium acetate, caused a significant increase in ICP when the arterial blood ammonia level exceeded 400 µmol ⋅ liter−1. A progressive elevation of blood ammonia concentration was followed by a gradual rise in CBF, measured by the xenon-133 clearance technique. At an arterial blood ammonia level exceeding 500 µmol ⋅ liter−1, the CBF reached a plateau at 30% above the mean control value. Increase in ICP correlated weakly, but significantly, with the increase in CBF (R = 0.489, p < 0.005). Elevation of the arterial blood ammonia level to 780.4 ± 25.5 µmol ⋅ liter−1 for 2 hours elicited a significant gradual increase in CSF formation rate, measured by the ventriculocisternal perfusion method with iodine-125-albumin as an indicator substance. A maximum increase in CSF flow of 81% was noted at the end of the ammonium acetate infusion. It is suggested that hyperammonemia increases ICP both by cerebral vasodilatation and by enhancement of the CSF formation rate.
Hormonal manipulation of meningiomas in vitro
Authors: Olson Jeffrey J. , Beck David W. , Schlechte Janet , Loh Pao-Min
Published: May 2009

✓ Speculation that meningiomas are subject to endocrine influence is supported by their higher incidence in women, reports of exacerbation of symptoms during pregnancy, and the discovery that these tumors harbor progesterone- and estrogen-binding proteins. To evaluate if these properties could be exploited therapeutically, specimens from three convexity meningiomas were used for estrogen- and progesterone-binding protein assays and establishment of tissue cultures. Each tumor (designated A, B, and C, respectively) was grown in experimental media containing 7.5 × 10−5 to 10−12 M 17β-estradiol, 2.5 × 10−4 to 10−12 M progesterone, 10−7 to 10−9 M tamoxifen (an estrogen antagonist), and 10−6 to 10−10 M RU486 (a progesterone antagonist). After incubation, cell growth was compared to control preparations by counting the meningioma cells present in each medium.

Tumors A, B, and C contained estrogen-binding proteins of 8.45, 13.6, and 26.9 fmol/mg cytosol protein and progesterone-binding proteins of 210, 130, and 126 fmol/mg cytosol protein, respectively. The media containing 17β-estradiol and progesterone caused 21% to 36% growth stimulation in Tumors A and B. In Tumor A, the addition of tamoxifen stimulated growth by 35%, while it caused only transient stimulation in Tumor B and had no effect on Tumor C. RU486, the progesterone antagonist, caused inhibition of cell growth in all three tumors, ranging from 18% to 36%.

These data suggest that selected meningiomas are subject to hormonal influence in vitro. The inhibition of meningioma growth in vitro by the antiprogesterone, RU486, has not been previously reported, and serves to encourage further development of alternative modes of therapy for recurrent and unresectable meningiomas.
Fenestrated clips for internal carotid artery aneurysms
Authors: Fujita Shigekiyo
Published: May 2009

✓ A new aneurysm clip has been developed specifically for internal carotid artery (ICA) aneurysms. This fenestrated clip's occluding blades deviate laterally, since the majority of ICA aneurysms protrude posterolateral to the parent artery. The clip was applied safely in seven recent patients with ICA aneurysms.
Neurotransmitters in the cerebral cortex
Authors: Jones Edward G.
Published: May 2009

✓ This article surveys the conventional neurotransmitters and modulatory neuropeptides that are found in the cerebral cortex and attempts to place them into the perspective of both intracortical circuitry and cortical disease. The distribution of these substances is related, where possible, to particular types of cortical neuron or to afferent or efferent fibers. Their physiological actions, where known, on cortical neurons are surveyed, and their potential roles in disease states such as the dementias, epilepsy, and stroke are assessed.

Conventional transmitters that occur in afferent fibers to the cortex from brain-stem and basal forebrain sites are: serotonin, noradrenaline, dopamine, and acetylcholine. All of these except dopamine are distributed to all cortical areas: dopamine is distributed to frontal and cingulate areas only. The transmitter in thalamic afferent systems is unknown.

Gamma aminobutyric acid (GABA) is the transmitter used by the majority of cortical interneurons and has a profound effect upon the shaping of receptive field properties. The vast majority of the known cortical peptides are found in GABAergic neurons, and the possibility exists that they may act as trophic substances for other neurons. Levels of certain neuropeptides decline in cases of dementia of cortical origin. Acetylcholine is the only other known transmitter of cortical neurons. It, too, is contained in neurons that also contain a neuropeptide.

The transmitter(s) used by excitatory cortical interneurons and by the efferent pyramidal cells is unknown, but it may be glutamate or aspartate. It is possible that excitotoxins released in anoxic disease of the cortex may produce damage by acting on receptors for these or related transmitter agents.
Chiasmal gliomas: appearance and long-term changes demonstrated by computerized tomography
Authors: Fletcher William A. , Imes Richard K. , Hoyt William F.
Published: May 2009

✓A survey of 22 cases showed the broad spectrum of lesions collectively termed “chiasmal gliomas.” Three computerized tomography (CT) patterns were diagnostic: a tubular thickening of the optic nerve and chiasm, a suprasellar tumor with contiguous optic nerve expansion, and a suprasellar tumor with optic tract involvement. Globular suprasellar tumors lacking these features required a histological examination for diagnosis. Tumor growth was documented by CT in only three chiasmal gliomas; all were the globular type. Failing visual function did not reflect chiasmal tumor growth, and stable vision did not exclude it. Both patients with tubular optic nerve thickening and two of three patients with unilateral optic nerve expansion had neurofibro-matosis. Five tumors became smaller after irradiation. Complications of radiation therapy included calcification of lenticular nuclei and remote infarcts. In patients who underwent biopsy, the CT appearance did not differentiate juvenile pilocytic astrocytoma from anaplastic astrocytoma. Thus, CT guides the diagnosis and neurosurgical treatment of chiasmal gliomas, establishing the need for biopsy or ventricular shunting.
Treatment of chronic subdural hematoma by twist-drill craniostomy with continuous catheter drainage
Authors: Camel Mark , Grubb Robert L.
Published: May 2009

✓ The case records of 114 patients were reviewed to ascertain the efficacy of bedside twist-drill craniostomy and continuous closed-system catheter drainage for the treatment of chronic subdural hematomas. Ninety-eight (86%) patients achieved an excellent outcome, and seven (6%) had no significant improvement. The total mortality from all causes was 8% in this group. Successful catheter drainage of the chronic subdural hematoma was accomplished by either one or two catheter placements in 102 (90%) patients. Twelve patients required additional operative procedures. The mean duration of hospitalization for the study group was 16 ays. No infections occurred in these patients. Remission of the clinical syndrome did not require the adiographic resolution of the chronic subdural hematoma.
Surgical treatment of cryptic AVM's and associated hematoma in the brain stem and spinal cord
Authors: Veerapen Richard J. , Sbeih Ibrahim Abdeaziz , O'Laoire Sean A.
Published: May 2009

✓ Most surgically treated cases of brain-stem hematomas have been attributed to rupture of cryptic arteriovenous malformations (AVM's); however, very few cases have been histologically proven. Similarly, there are very few reports of surgically treated spontaneous hematomyelia, in which the hemorrhage has been histologically confirmed as being due to a purely intramedullary AVM. The authors report three cases with surgically treated, histologically confirmed AVM's, of which two were in the brain stem and the third was in the spinal cord. In all these cases, abnormal vascular tissue in the wall of the hematoma cavity was recognized at operation and excised.
Changes in superior sagittal sinus pressure in children with head elevation, jugular venous compression, and PEEP
Authors: Grady M. Sean , Bedford Robert F. , Park T. S.
Published: May 2009

✓ Air embolism is a potential hazard during craniotomy whenever intracranial venous pressure is subatmospheric. In order to better understand both the risk of air embolism and its treatment in neurosurgical patients, the authors have investigated the relationship of superior sagittal sinus pressure (SSP) to head position in 15 children and examined the effects of both jugular venous compression and positive end-expiratory airway pressure (PEEP) on SSP. Progressive head elevation significantly decreased mean SSP and, in five patients, SSP was less than 0 mm Hg at 90° torso elevation. A PEEP of 10 cm H2O was ineffective in significantly increasing SSP at any degree of head elevation, whereas bilateral internal jugular compression always caused a significant increase in SSP. The authors conclude that children are at risk for venous air embolism when undergoing suboccipital craniectomy in the sitting position because intracranial venous pressure is often subatmospheric when the head is elevated. Furthermore, maintaining PEEP does not appear to be a reliable treatment for increasing SSP, whereas bilateral internal jugular compression is effective.
Subtle deterioration in shunted childhood hydrocephalus
Authors: Fried Arno , Shapiro Kenneth
Published: May 2009

✓ Eighteen hydrocephalic children who presented with subtle deterioration when their shunts malfunctioned were studied during shunt revision by means of the pressure-volume index (PVI) technique. Bolus manipulation of cerebrospinal fluid (CSF) was used to determine the PVI and the resistance to the absorption of CSF (Ro). Ventricular size was moderately to severely enlarged in all the children. Steady-state intracranial pressure (ICP) at the time of shunt revision was 17.5 ± 7.3 mm Hg (range 8 to 35 mm Hg). Pressure waves could not be induced by bolus injections in the 8- to 35-mm Hg range of ICP tested. The mean ± standard deviation (SD) of the predicted normal PVI for this group was 18.5 ± 2.7 ml. The mean ± standard error of the mean of the measured PVI was 35.5 ± 2.1 ml, which represented a 187% ± 33% (± SD) increase in volume-buffering capacity (p < 0.001). The ICP did not fall after bolus injections in three children, so that the Ro could not be measured. In the remaining 15 patients, Ro increased linearly as a function of ICP (r = 0.74, p < 0.001). At ICP's below 20 mm Hg, Ro ranged from 2.0 to 5.0 mm Hg/ml/min, but increased to as high as 21 mm Hg/ml/min when ICP was above 20 mm Hg.

This study documents that subtle deterioration in shunted hydrocephalic children is accompanied by abnormally compliant pressure-volume curves. These children develop ventricular enlargement and neurological deterioration without acute episodic pressure waves. The biomechanical profile of this group differs from other children with CSF shunts.
RG2 glioma growth in rat cerebellum after subdural implantation
Authors: Krajewski Stanislaw , Kiwit Jürgen C. W. , Wechsler Wolfgang
Published: May 2009

✓ The nitrosourea-induced rat glioma clone RG2 was tested for its capacity to form multicellular tumor spheroids (MTS's). Resulting spheroids were investigated by light and electron microscopy with regard to their proliferation patterns and morphological features. Using microsurgical techniques and avoiding mechanical injury of the brain tissue, the authors successfully transplanted avascular MTS's under the dura of the cerebellum, above the vermis, in 43 adult syngeneic Fischer CD rats. The rate of tumor establishment was 93%, and the tumors that were solid and spheroid in shape grew exponentially. Neovascularization could be observed at 3 days after implantation, and invasion of the cerebellum occurred by 3 to 5 days. Neurological deterioration, including ataxia, impairment of walking, and apathy, could be observed after 10 days. The mean survival time was approximately 16 days. The subdural cerebellar tumors were studied by histological techniques, and two morphometric methods were applied to check the growth of implanted spheroids. All tumors were deeply stained with the Evans blue dye-albumin complex, demonstrating disturbance of the blood-brain barrier.

The easy accessibility of the cerebellar vermis in rats, the microsurgical implantation of glioma spheroids under the dura avoiding nerve tissue disruption, and the high percentage of reproducible establishment of tumors favor this experimental brain-tumor model. This should be an excellent model for study of experimental therapies.
Barbiturate protection against hypoxic neuronal damage in vitro
Authors: Aitken Peter G. , Schiff Steven J.
Published: May 2009

✓ Hippocampal tissue slices in vitro were exposed to periods of hypoxia of different durations. Addition of pentobarbital to the perfusion medium significantly increased the duration of hypoxia that was survived by CA1 pyramidal cells.