bluuebunny/crossref_metadata_2025_split huggingface dataset:
Indications for surgical intervention in middle cerebral artery obstruction
Authors: Day Arthur L. 
Published: May 2009

✓ The clinical, angiographic, and surgical characteristics of 31 patients with high-grade middle cerebral artery (MCA) stenosis or occlusion (jointly termed “MCA obstructions”) referred for cerebral revascularization by extracranial-intracranial (EC-IC) bypass are reviewed. Overall, 12 (66%) of the 18 patients with stenosis and all 13 (100%) of those with complete occlusion experienced clinically evident infarctions. Twenty-five of these patients underwent arteriography at least twice during their clinical course. Eleven (44%) demonstrated significant improvement in flow or complete resolution of obstruction on their second study. Ten of these 11 were patients in whom the initial arteriography was done within 2 weeks of symptom onset. Five other patients with stenosis exhibited obstruction that was worse on serial arteriography without surgical intervention.
The high incidence of resolution of MCA obstructions indicates that surgery should not be contemplated in most instances until delayed arteriography has been performed, at least 6 weeks after the onset of symptoms. Proximal embolic sources, such as the cervical carotid bifurcation, should receive carotid endarterectomy and repeat arteriography in appropriate patients prior to consideration of EC-IC bypass. Persistent high-grade MCA obstructions are thereafter potential candidates for EC-IC bypass, since leptomeningeal collateral vessels are marginal in their protective ability. Overall, of 15 patients who underwent an EC-IC bypass procedure, 14 were either stable or improved postoperatively, and 13 have been free of any further ischemic events without the use of major anticoagulant agents.
The value of computerized tomography in aneurysmal subarachnoid hemorrhage
Authors: Gurusinghe Nihal T. , Richardson Alan E. 
Published: May 2009

✓ Of 256 patients with aneurysmal subarachnoid hemorrhage, 131 underwent computerized tomographic (CT) scanning within 7 days of the ictus. These scans were analyzed in order to assess the quantity of blood in the main subarachnoid cisterns and cerebral fissures. The method of quantification used recognized the horizontal and vertical components of the largest clot visible on the CT scan and expressed this as the “CT score.” Angiographic vasospasm was assessed and graded, based on reduction in the caliber of the major cerebral vessels. The CT score was then compared to 1) the incidence of angiographic vasospasm, 2) the clinical course, and 3) the eventual outcome. Of the patients who showed no blood on the initial CT scan, 87% were admitted in good clinical grades, whereas among patients with higher CT scores the number admitted in poor clinical grades increased. The degree of angiographic vasospasm did not relate as closely as the CT score to the clinical grade on admission or to the subsequent clinical course.
The final outcome was assessed on follow-up review, and those acquiring neurological deficits from ischemic neurological dysfunction (IND) were identified. Ninety percent of patients with no blood on the CT scan (CT score 0) had a good outcome, while 5% sustained the effects of IND. The incidence of IND gradually increased with a rise in the CT score until, with scores of 8 and above, 90% of patients suffered the ill effects of IND. The CT score proved to be a simple yet accurate prognostic indicator of the outcome of IND.
Cerebrospinal fluid shunt infection
Authors: Walters Beverly C. , Hoffman Harold J. , Hendrick E. Bruce , Humphreys Robin P. 
Published: May 2009

✓ A retrospective study of the management of patients with infected cerebrospinal fluid (CSF) shunts was undertaken, covering the 20 years from 1960 to 1979, inclusive, and involving 222 patients with 267 infections. The data were analyzed with emphasis on influences surrounding treatment choice and subsequent outcome. Treatment was classified into three major categories: medical management (antibiotics alone), surgical management (antibiotics plus operative removal of the infected shunt), and no treatment (ranging from admission and observation only to shunt revision), the diagnosis of shunt infection having been missed. Results showed surgical treatment to be more efficacious than medical or no treatment, with a higher rate of initial cure, and lower morbidity and mortality rates.
Also examined were the relationships among clinical presentation, infection rate, and results of specimens sent for culture, and initial treatment. The definitive nature of initial treatment was revealed to be directly proportional to the aggressiveness of microbiological investigation. This latter aspect was related to clinical presentation, with shunt malfunction being the least recognized symptom of shunt infection. Patients presenting with blocked shunts were less likely to receive therapy appropriate for infection than any other group, leading to the conclusion that shunt malfunction may be more specific to infection than heretofore believed.
Hemodynamically significant stenosis of the internal carotid artery treated with endarterectomy
Authors: Vorstrup Sissel , Engell Hans Christian , Lindewald Helle , Lassen Niels Alexander 
Published: May 2009

✓ Repeated cerebral blood flow (CBF) measurements with xenon-133 inhalation and single photon emission tomography were performed in a patient suffering a minor stroke with subsequent orthostatic-provoked transient ischemic attacks (TIA's). Angiography revealed a thread-like internal carotid artery and an occluded external carotid artery on the side of the ischemic neurological symptoms. Computerized tomography and technetium-99m-pertechnetate brain scintigraphy 2 weeks after stroke were both normal. Before reconstructive vascular surgery, resting CBF showed a hypoperfused area corresponding to the clinical symptoms. Diamox (acetazolamide, 1 gm) increased CBF by 24% in the unaffected hemisphere, whereas even a slight decrease in flow (“steal”) was seen in the maximally affected region. In contrast, theophylline (220 mg) reduced CBF in the unaffected hemisphere and caused a slight increase in the previously maximally hypoperfused area (“inverse steal”). After surgery, the flow pattern practically normalized and the TIA's disappeared.
The CBF measurements before surgery and also after the injection of the vasoactive drugs indicated that focal hemodynamic insufficiency elicited the TIA's, and pointed at a low mean arterial blood pressure of about 35 mm Hg in the affected hemisphere. The perioperative finding of a mean blood pressure in the internal carotid artery of 31 mm Hg on the symptomatic side confirmed that the brain tissue had a severely reduced perfusion pressure. On clamping the artery, a stump pressure of 22 mm Hg and electroencephalogram flattening was noted, so a temporary internal shunt was inserted. The findings demonstrate that preoperative CBF measurements, including studies of the regional vasoreactivity, may identify patients with hemodynamic TIA's. These patients are at particular risk of developing cerebral ischemia during carotid endarterectomy, as any further compromise of the inflow may precipitate frank ischemia.
Absent or compressed basal cisterns on first CT scan: ominous predictors of outcome in severe head injury
Authors: Toutant Steven M. , Klauber Melville R. , Marshall Lawrence F. , Toole Belinda M. , Bowers Sharon A. , Seelig John M. , Varnell James B. 
Published: May 2009

✓ The relationship of outcome to the appearance of the basal cisterns as seen on initial computerized tomography (CT) scanning was assessed in 218 consecutive severely head-injured patients entered into the second phase of the National Pilot Traumatic Coma Data Bank. Outcome could be directly related to the status of the basal cisterns on the initial CT scan. The mortality rates were 77%, 39%, and 22% among those with absent, compressed, and normal basal cisterns, respectively. This association between cisterns and outcome was shown to be strong after adjusting for Glasgow Coma Scale (GCS) score (p < 0.001).
The state of the cisterns was more important for those with higher GCS scores (scores 6 to 8) than for those with lower scores (scores 3 to 5). Patients with GCS scores of 6 to 8, with cisterns absent or not visualized, suffered nearly a fourfold additional risk of poor outcome, compared to those with normal cisterns. This indicates that the status of the cisterns can be used as an early noninvasive method of identifying patients at high risk of death or severe disability, in whom the initial neurological examination would potentially suggest otherwise.
Factors causing acute shunt infection
Authors: Renier Dominique , Lacombe Jacques , Pierre-Kahn Alain , Sainte-Rose Christian , Hirsch Jean-François 
Published: May 2009

✓ A series of 1174 operations performed on 802 hydrocephalic children was analyzed in an effort to find the factors causing acute postoperative infection. Culture of the cerebrospinal fluid (CSF) samples during the operation was positive in 33 cases. These cases were excluded from the series. Ninety infections were observed in the remaining 1141 operations, an overall rate of 7.9%. Most of these infections were meningitis (56 cases). Staphylococcus epidermidis was the bacterium most frequent identified (44%).
Statistically significant relationships were found between shunt infection and the following factors: 1) age: infection was 2.6 times as frequent before 6 months than after 1 year of age (p = 0.03); 2) poor condition of the skin; 3) presence of intercurrent seats of infection at the time of surgery; 4) type of operation: the rate of infection was 8.4% in primary shunt insertions, 5% in shunt revisions, and 17.5% in reinsertions following shunt removal for infection (p = 0.0001); 5) end of the shunt requiring revision: an infection rate of 7.7% followed revision of the ventricular catheter alone, and 2.6% followed revision of the other end alone (p = 0.012); and 6) postoperative wound dehiscence or scalp necrosis. The surgical team involved was poorly correlated with the rate of infection (p = 0.12).
No statistically significant relationships have been found between infection and 1) etiology of hydrocephalus; 2) sex; 3) recent neurosurgical operation before the shunt procedure; 4) preoperative presence of an external drainage tube or CSF fistula; 5) lumbar or ventricular taps, or ventriculography; 6) number of previous operations performed on the shunt; 7) time (month and year) of operation; or 8) sugar level and cell count in the CSF.
The perforating branches of the middle cerebral artery
Authors: Umansky Felix , Gomes Francisco B. , Dujovny Manuel , Diaz Fernando G. , Ausman James I. , Mirchandani Haresh G. , Berman S. Kim 
Published: May 2009

✓ The perforating branches (PFB's) of the middle cerebral artery (MCA) were studied in 34 unfixed brain hemispheres which were injected with a polyester resin and dissected under the operating microscope. Five hundred and eight vessels were identified and their site of origin, branching pattern, outer diameter (OD), and length recorded. Four hundred and two PFB's (79%) originated from the main trunk of the MCA before its division; the remaining 106 vessels (21%) had their origin from branches of the MCA as follows: superior trunk, 43 vessels (8.5%); inferior trunk, 30 vessels (6%); middle trunk, four vessels (0.8%); early temporal branch, 27 vessels (5.3%); and early frontal branch, two vessels (0.4%). The number of PFB's in each hemisphere varied from five to 29 (mean 14.9 ± 0.7 vessels). The great majority of PFB's (96%) originated along the proximal 17 mm of the MCA. The PFB's arising in the first 10 mm had a mean OD of 0.35 ± 0.01 mm and a mean length of 9.25 ± 0.19 mm, and those arising from the second 10 mm had a mean OD of 0.47 ± 0.02 mm and a mean length of 16.67 ± 1.4 mm. A clear distinction between a medial and lateral group of PFB's was present in only 14 hemispheres (41%). In nine hemispheres (26%), perforating vessels from the anterior cerebral artery (A1 segment) and from the recurrent artery of Heubner replaced the medial group of PFB's of the MCA. In one case this group originated in an accessory MCA. In three hemispheres (9%) a small anastomosis (OD 0.2 mm) was seen between a PFB of the recurrent artery of Heubner and one of the MCA. From a total of 508 PFB's, 255 vessels (50%) originated as single vessels, while 253 vessels (50%) originated as branches of common stems. The OD of the single vessels ranged from 0.1 mm to 1.1 mm (mean 0.39 ± 0.02 mm), and the length from 3 to 20 mm (mean 10.8 ± 0.2 mm). The common stems ranged in OD from 0.6 to 1.8 mm (mean 0.87 ± 0.04 mm), and in length from 1 to 15 mm (mean 4.1 ± 0.4 mm).
The clinical application of these anatomical data to the management of aneurysms and arteriovenous malformations of the MCA, and in the field of interventional neuroradiology is described. The most frequent pathological entities involving the perforating vessels are also discussed.
Experimental feline hydrocephalus
Authors: Shapiro Kenneth , Takei Futoshi , Fried Arno , Kohn Ira 
Published: May 2009

✓ In a craniectomy-durectomy model of kaolin-induced feline hydrocephalus, the pressure-volume index (PVI) technique of bolus manipulations of cerebrospinal fluid (CSF) was used to study the biomechanical changes associated with hydrocephalus. Steady-state intracranial pressure (ICP), PVI, and the resistance to the absorption of CSF were determined acutely and 3 to 5 weeks later in hydrocephalic cats and time-matched control cats. Steady-state ICP was 11.0 ± 2.1 mm Hg (± standard deviation) in the hydrocephalic cats, compared to 10.8 ± 2.2 mm Hg in the chronic control group (p > 0.1). The ICP in both the chronic hydrocephalic and chronic control groups was significantly higher (p < 0.001) than after acute durectomy (mean ICP 8.5 ± 1.2 mm Hg). Immediately after dural opening, the mean PVI was 3.6 ± 0.2 ml (± standard error of the mean); over time, it decreased to 1.3 ± 0.1 ml in the chronic control group (p < 0.001), but remained elevated in the hydrocephalic group at 3.5 ± 0.4 ml (p < 0.001). Resistance to CSF absorption was 9.1 ± 1.4 mm Hg/ml/min immediately after dural opening and increased to 28.8 ± 4.5 mm Hg/ml/min (p < 0.001) in the hydrocephalic cats; it increased even further in the chronic measurements in control cats, to 82.3 ± 9.2 mm Hg/ml/min (p < 0.001). Ventricular size was moderate to severely enlarged in all hydrocephalic cats, and normal in the control group.
These results indicate that the biomechanical profile of the altered brain container model of kaolin-induced feline hydrocephalus resembles that described in hydrocephalic infants. As shown in the control subjects, an absorptive defect alone is not sufficient to cause progressive ventricular enlargement. Increased volume-buffering capacity coupled with a moderate increase of CSF absorption resistance facilitates volume storage in the ventricles.
Arteriovenous malformations of the lateral ventricle
Authors: Waga Shiro , Shimosaka Shinichi , Kojima Tadashi 
Published: May 2009

✓ Nine cases with arteriovenous malformations (AVM's) predominantly involving the lateral ventricle are presented. All the AVM's were small, but caused intraventricular hemorrhage in eight cases. Only two patients had an intracerebral hemorrhage large enough to warrant evacuation. Eight patients were under the age of 40 years at the onset of their disease. Computerized tomography demonstrated intraventricular hemorrhage in eight patients, and after intravenous administration of contrast medium a small area of enhancement with dilated subependymal draining veins was seen in seven. The lateral ventricles were of normal size in seven cases, and only two patients required a shunting procedure. Angiography demonstrated that the lesion was an AVM in eight patients, and did not visualize the lesion in the ninth. One patient suffered a recurrent intraventricular hemorrhage when the AVM was demonstrated, although repeated angiography had failed to disclose a vascular lesion at his first intraventricular hemorrhage 14 months before.
All nine lesions were resected by microsurgical techniques, and the results were excellent in eight patients. Of four caudate lesions, three were resected through a frontal transcortical approach and the other was operated on through an anterior transcallosal approach; the results were excellent in three of these patients. Only one (Case 4) was left with neurological deficits; he had confusion and disorientation following a right frontal transcortical approach. Even in the dominant hemisphere, lesions in the head of the caudate nucleus could be safely resected by an anterior transcallosal approach. Two choroidal lesions located in the temporal horn and trigone on the dominant side were resected through a middle temporal gyrus approach, and three thalamic lesions through a posterior transcallosal approach, all with excellent results. In all cases the brain opening required was about the width of the retractor (maximum 2.0 cm, average 1.5 cm).
Infratentorial arachnoid cysts
Authors: Galassi Ercole , Tognetti Francesco , Frank Franco , Fagioli Leo , Nasi Maria Teresa , Gaist Giulio 
Published: May 2009

✓ The infratentorial compartment represents the second most common location of arachnoid malformations. Ten arachnoid cysts of the posterior fossa, operated on between 1970 and 1983, are reviewed. These lesions, although congenital and developmental in nature, may present at any age, and males are more frequently affected. A high rate of birth-related trauma (50% in this series) is conceivably due to fetal macrocranium, and the enlarged head and psychomotor retardation prevail in infancy and childhood. In arachnoid cysts occurring during adulthood, symptoms and signs more clearly indicate a dysfunction of the posterior fossa.
Besides computerized tomography, pneumoencephalography and metrizamide techniques are recommended to rule out a Dandy-Walker syndrome in doubtful cases, and to obtain information about the cerebrospinal fluid (CSF) circulation. It is particularly important to establish the presence and type of communication of cysts with the CSF pathways. Although infratentorial cysts often communicate, they can be space-occupying masses because of increasing CSF retention, which may be due to a ball-valve mechanism or to inadequate communication. The frequently associated hydrocephalus (seven of the 10 cases in this series had hydrocephalus) seemed to be dependent mainly upon mechanical factors. The authors discuss the indications for intracranial surgery versus shunting procedures and report the results achieved by direct cyst excision.
Stem cell studies of human malignant brain tumors
Authors: Pertuiset Bertrand , Dougherty Dolores , Cromeyer Carlos , Hoshino Takao , Berger Mitchel , Rosenblum Mark L. 
Published: May 2009

✓ The proliferation kinetics were studied in early-passage cultures of cells from 13 human malignant brain tumors and two specimens of normal brain under conditions similar to those used in clonogenic cell-survival studies. Autoradiography was performed in all but four cases to estimate the fraction of cells actively replicating deoxyribonucleic acid (DNA), the approximate cell cycle time, and the effect of low-dose tritiated thymidine on cell proliferation. The mean tumor cell doubling time (TD) was 53 hours for five glioblastomas, 46 hours for two ependymomas, and 83 hours for two medulloblastomas. A gliosarcoma grew fastest (TD = 22 hours) in culture and a pilocytic astrocytoma grew slowest (TD = 144 hours). The approximate cell cycle time ranged from 1 to 2.5 days for all tumors tested. This suggests that chemotherapeutic agents that predominantly kill proliferating cells should be administered in vitro for at least 2 to 2.5 days to achieve maximum cell kill.
The approximate growth fraction ranged from 0.65 to 0.96 for all tumors except for the two medulloblastomas and the pilocytic astrocytoma, which had growth fractions of 0.34 and 0.35, respectively. Most laboratories investigating the chemosensitivity of primary or early-passage human tumor cells require that 40% to 70% of cells be killed to consider a drug active in vitro. The results of this study suggest that the cell-cycle-specific agents cannot achieve a high enough cell kill to be considered active for some tumors that grow slowly in culture. An estimate of the in vitro growth rate is necessary to reliably interpret cell-survival results with such agents.
Tritiated thymidine appeared to slow cell proliferation in some of the cultures, presumably as a result of radiation-induced DNA damage caused by tritium that had been incorporated into DNA. The degree to which cell growth was slowed in individual tumors correlated with the patient's clinical response to radiation therapy and postoperative survival time.
Source of fibrin/fibrinogen degradation products in the CSF after subarachnoid hemorrhage
Authors: Vermeulen Marinus , van Vliet Huub H. D. M. , Lindsay Kenneth W. , Hijdra Albert , Gijn Jan van 
Published: May 2009

✓ In 48 patients with a subarachnoid hemorrhage, levels of fibrin/fibrinogen degradation products (FDP's), total protein, and plasminogen were measured in the cerebrospinal fluid (CSF) between Days 9 and 15 after the bleed. Of these 48 patients, 22 received tranexamic acid. Despite a significant reduction in the incidence of rebleeding in patients taking tranexamic acid, no difference in FDP levels was found between patients receiving tranexamic acid and a control group of patients who were not; nor was any relationship evident between FDP levels and rebleeding. In patients with detectable levels of FDP's, CSF protein and plasminogen values were also increased, and FDP's were found more frequently in the CSF of patients with an impaired level of consciousness or with a neurological deficit.
These findings suggest that in the 2nd week after subarachnoid hemorrhage, the presence of FDP's in the CSF reflects a damaged blood-CSF barrier rather than ongoing local fibrinolysis in the subarachnoid space. A finding of FDP's in the CSF is, therefore, an unreliable monitor of antifibrinolytic treatment in subarachnoid hemorrhage and cannot be used for selecting patients at high risk of rebleeding.
Acute brain edema in fatal head injury: analysis by dynamic CT scanning
Authors: Yoshino Eiji , Yamaki Tarumi , Higuchi Toshihiro , Horikawa Yoshiharu , Hirakawa Kimiyoshi 
Published: May 2009

✓ Dynamic computerized tomography (CT) was performed on 42 patients with acute head injury to evaluate the hemodynamics and to elucidate the nature of fatal diffuse brain bulk enlargement. Patients were divided into two groups according to the outcome: Group A included 17 nonfatally injured patients, eight with acute epidural hematomas and nine with acute subdural hematomas; Group B included 25 fatally injured patients, 16 with acute subdural hematomas and nine with bilateral brain bulk enlargement. Remarkable brain bulk enlargement could be seen in all fatally injured patients with acute subdural hematoma. In 29 (69%) of 42 patients, dynamic CT was performed within 2 hours after the impact.
In the nonfatally injured patients with brain bulk enlargement, dynamic CT scans suggested a hyperemic state. On the other hand, in 17 (68%) of the 25 fatally injured patients, dynamic CT scans revealed a severely ischemic state. In the fatally injured patients with acute subdural hematoma, CT Hounsfield numbers in the enlarged hemisphere (hematoma side) were significantly lower than those of the opposite side (p < 0.001). Severe diffuse brain damage confirmed by follow-up CT scans and uncontrollable high intracranial pressure were noted in the fatally injured patients. Brain bulk enlargement following head injury originates from acute brain edema and an increase of cerebral blood volume. In cases of fatal head injury, acute brain edema is the more common cause of brain bulk enlargement and occurs more rapidly than is usually thought.