bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Phase III comparison of BCNU, hydroxyurea, and radiation therapy to BCNU and radiation therapy for treatment of primary malignant gliomas
Authors: Levin Victor A. , Wilson Charles B. , Davis Richard , Wara William M. , Pischer Tana L. , Irwin Lowell 
Published: May 2009

✓ This Phase III clinical trial compared the effectiveness of the combination of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), radiation therapy, and hydroxyurea (BHR group) to the combination of BCNU and radiation therapy (BR group) for the treatment of malignant gliomas. In both arms of the study, BCNU was administered intravenously for 3 consecutive days before the initiation of radiation therapy, and at 8-week intervals thereafter until unequivocal tumor progression. In the BHR arm of the study, hydroxyurea was administered orally on alternate days during radiation therapy. Patients in each arm were stratified almost equally by tumor type (glioblastoma multiforme (GM) or other nonglioblastoma multiforme malignant gliomas (NGM)) and extent of surgical resection of tumor. Patients were also evaluated with the Karnofsky Performance Status (KPS) scale. Time to progression was determined by comparing the results of sequential neurological examinations and radionuclide and computerized tomographic scans.
Of the 130 patients entered into the study, 99 constitute the valid study group. Data were analyzed with Kaplan-Meier representations and the statistical methods of Gehan and Cox. The NGM patients with KPS ratings of ≥60 did better on both arms of the study, with median times to tumor progression (MTP's) of 50 and 72 weeks for BHR and BR, respectively. However, GM patients showed statistically significant differences (p = 0.03) between the two arms of the study, with MTP's of 41 and 31 weeks for BHR and BR, respectively. The GM patients with subtotal tumor resection did slightly better on BHR than on BR, with MTP's of 49 weeks (p = 0.03) and 31 weeks for the respective groups.
Treatment of intracavernous and giant carotid aneurysms by combined internal carotid ligation and extra- to intracranial bypass
Authors: Gelber Benjamin R. , Sundt Thoralf M. 
Published: May 2009

✓ Ten patients with intracranial internal carotid artery (ICA) aneurysms were managed by combining ICA ligation with an extracranial to intracranial bypass procedure. Nine of these grafts were proven patent by angiogram. One patient was unable to return for postoperative angiograms; his graft had appeared patent on physical examination. Seven aneurysms were intracavernous, two were giant carotid-ophthalmic aneurysms, and one aneurysm was at the intracranial bifurcation of the ICA. Despite occlusion cerebral blood flow (CBF) measurements of 20 ml/100 gm/min or less in six patients, only one patient was unable to tolerate ICA ligation. Three patients developed transient aphasia, but there were no permanent neurological deficits associated with the carotid occlusion. Seven patients had improvement in pre-existing extraocular palsies or visual field defects. Others remained stable.
The combination of an extracranial to intracranial microvascular bypass procedure with ICA ligation seems to be an effective method of treatment for aneurysms near the base of the skull that cannot be obliterated by a direct intracranial approach. The addition of the bypass procedure permits ICA ligation in patients who would not otherwise have tolerated occlusion of that vessel. Intraoperative xenon CBF measurements are an important adjunct to the operation.
Nonoperative treatment of brain abscesses in selected high-risk patients
Authors: Rosenblum Mark L. , Hoff Julian T. , Norman David , Edwards Michael S. , Berg Bruce O. 
Published: May 2009

✓ In a series of eight high-risk patients, presumed intraparenchymal pyogenic brain abscesses resolved or decreased markedly in size with antibiotic therapy and without surgery. Cases were selected for antibiotic trial because of multiplicity or location of the abscesses and complicating medical conditions. Patients were alert or lethargic, with stable or improving early clinical courses. Diagnosis was made by computerized tomography (CT) brain scans and corroborative laboratory and diagnostic studies. Cases were closely monitored with serial CT scans. In six cases, bacteria were cultured from blood, cerebrospinal fluid, or fluid aspirated from one of multiple abscesses. Antibiotics were selected for specificity against the cultured organism, or consisted of high-dose penicillin plus chloramphenicol; therapy continued for a median of 7 weeks.
Serial CT scans showed decreased abscess size by a mean of 2.4 weeks (range, 1 to 4 weeks) and resolution of contrast-enhancement and mass effects by a mean of 9.8 weeks (range, 8 to 14 weeks). Abscesses followed to resolution were significantly smaller (mean, 1.7 cm diameter, p < 0.01) than those not responding to similar courses of antibiotic therapy (mean, 4.2 cm diameter). Two patients died of causes unrelated to their abscesses; surviving patients have no neurological deficit (mean follow-up period, 25 months; range, 15 to 37 months). Guidelines are recommended for a treatment protocol to be cautiously applied for high-risk patients with small abscesses. Surgery is recommended in all other cases of pyogenic brain abscesses.
Neurosurgical treatment of pathological fracture-dislocation of the spine
Authors: Perrin Richard G. , Livingston Kenneth E. 
Published: May 2009

✓ The treatment of 20 patients with symptomatic pathological fracture-dislocation of the spine is reviewed. The single most common primary disease was carcinoma of the breast (12 cases). Pain was the presenting symptom in 19 patients. At the time of surgery, six patients were weak but ambulatory, seven were bedridden, and three were paraplegic. The cervical spine (10 cases) was most frequently involved, followed by the thoracic region in six, and the lumbar segments in four. Treatment aimed at improving or preserving neurological function involved decompression of the cord (or cauda) with reduction of bone deformity and stabilization of the spine. Laminectomy decompression was performed in 18 cases. Posterior rib graft fusion was used to stabilize the spine in all patients with cervical, and in three with upper thoracic, pathological fracture-dislocation; Harrington rod instrumentation was used for lower thoracic and lumbar levels. All patients were considered for radiotherapy and/or chemotherapy. Ten patients are living, an average of 20 months following surgery. Among the remainder, the average survival was 5 months. Fourteen patients were ambulatory after surgery, four were improved, and two were unchanged. Twelve patients have achieved a “satisfactory” result (walking and continent 6 months after treatment), including the three who were paraplegic at the time of surgery.
Spinal metastases presenting as pathological fracture-dislocation of the spine may produce potentially devastating cord compression. Critical neurological sequelae can be avoided, and a satisfactory result can be achieved by urgent decompression of the cord and stabilization of the spine.
Spinal Cord Blood Flow in Experimental Transient Traumatic Paraplegia
Authors: Lohse Dean C. , Senter Howard J. , Kauer John S. , Wohns Richard 
Published: May 2009

✓ Blood flow in the lateral funiculus of the thoracic spinal cord was measured in 24 anesthetized cats using the hydrogen clearance method. In a control series of eight nontraumatized animals, blood flow measurements were taken from the T-5 and T-6 segments for 6 consecutive hours. The mean spinal cord blood flow (SCBF) in the control group was 12.8 ± 3.51 (SD) ml/min/100 gm on the basis of 107 measurements over 6 hours. In the experimental groups, 16 animals were similarly prepared. The spinal cords of these animals were then traumatized by dropping a 20-gm weight 5 cm (100 gm-cm trauma) or 13 cm (260 gm-cm trauma) onto the T-5 segment. Previous experiments have shown that these trauma levels lead to a transient paraplegia of less than 10 and 30 days' duration, respectively. Two hundred blood flow measurements from T-5 and T-6 were taken over the 6 hours following trauma. In the seven animals of the 100 gm-cm group, mean SCBF after trauma from the T-5 segment was 12.6 ± 3.45 (SD) ml/min/100 gm on the basis of 50 measurements taken over 6 hours; not significantly different from the controls (p > 0.70). In the 260 gm-cm group, mean SCBF from T-5 for 6 hours after trauma was 17.3 ± 6.60 (SD) ml/min/100 gm; significantly higher than controls (p < 0.001). Mean SCBF 3 to 6 hours after trauma was significantly elevated over controls (p < 0.05). The mean hyperemia in the 260 gm-cm group was found to be due to marked hyperemia in only four animals of the series, while five animals maintained blood flows in the normal range.
This experiment provides quantitative evidence that white matter ischemia does not occur in spinal cord injuries that can be expected to produce only transient paraplegia. The data support the concept that white matter ischemia in the acute phase of severe spinal cord trauma may be related to secondary injury and subsequent permanent paraplegia.
The intracranial pressure in infants
Authors: Welch Keasley 
Published: May 2009

✓ In infancy, the intracranial pressure (ICP) is normally maintained at a level that is very low by standards that apply later in life. There is little or no overlap of normal pressure and the pressure in infantile hydrocephalus. Knowledge of the normal pressure may allow expectant management of milder instances of infantile hydrocephalus.
During the first few days after birth, as the volume of the brain decreases so does its turgor, and subatmospheric ICP is common. Hydrocephalus may be masked or attenuated in severity during that time or may be incorrectly suspected in a normal child because of the increase in circumference of the head accompanying the restitution of volume. The postnatal decrease in ICP may be responsible for ventricular hemorrhage in the newborn.
Experimental syringomyelia
Authors: Hall Peter , Turner Michael , Aichinger Steven , Bendick Phillip , Campbell Robert 
Published: May 2009

✓ The influence of ventricular pressure changes on syrinx pressure was investigated in this study of experimental canine kaolin-induced syringomyelia. The pressures of the ventricles, syrinx, and cervical subarachnoid space were measured. A complete ventriculosubarachnoid block occurred in the animals with syringomyelia. The baseline syringeal pressures exceeded those of both the ventricles and the subarachnoid space. Raising ventricular pressure elevated the syringeal pressure, but aspiration of ventricular fluid did not acutely lower the pressure. These findings suggest a ventriculosyrinx valve effect that may inflate the syrinx during transient rises of intracranial pressure.
A respiratory pressure pattern was found in the syrinx similar to that of the ventricles and subarachnoid space. This wave was reduced but not abolished by ligating the subarachnoid space distal to the syrinx. The arterial pulse was much diminished within the syrinx at rest. These findings indirectly support the possibility that transmission of thoracic pressures to the spinal subarachnoid space with compression of the syrinx is a principal force that enlarges the syrinx.
Physiological features of the pressure-volume function of brain elasticity in man
Authors: Sklar Frederick H. , Beyer Chester W. , Clark W. Kemp 
Published: May 2009

✓ The intracranial pressure-volume relationship of brain elasticity was examined in 20 patients with suspected disorders of the cerebrospinal fluid (CSF) system. Elasticity measurements were made as the patients were studied with a servo-controlled lumbar infusion technique to measure CSF absorptive capacity. The data were evaluated to determine the relationship between intracranial pressure (ICP) and volume, and between ICP variability and the level of ICP. The results confirm the exponential nature of the pressure-volume elasticity function in patients who are not critically ill. Eight of the 20 patients were shown to have normal CSF absorptive capacities, and there was no difference between their elasticity measurements and those of patients with absorptive defects. In addition, ICP variability was shown to be linearly related to the actual level of ICP.
The physiological features of the pressure-volume elasticity function are reviewed. Based on these considerations, the clinical value and significance of elasticity measurements is questioned.
Invading meningiomas of the sphenoid ridge
Authors: Bonnal Joël , Thibaut André , Brotchi Jacques , Born Jacques 
Published: May 2009

✓ The authors report a series of 34 meningiomas of the sphenoid ridge. Eight tumors were totally removed uneventfully: two from the middle sphenoid ridge and six from the pterion or Sylvian point. Five tumors were not operated on because of their extensions or the patient's age. Twenty-one tumors raised serious surgical problems, resulting in a classification into three groups: deep or clinoidal, invading beyond the sphenoid wings, and a combination of both. Histological study of the hyperostotic bone showed meningiomatous cells in the bone in 12 of 13 cases so examined.
Surgical limitations included invasion of the cavernous sinus (15 cases), of the dura mater of the sella turcica (seven cases), of the lateral part of the sphenoid body at the insertion point of the ala magna (seven cases), and of the common tendinous annulus of Zinn in the orbit (five cases), and basilar extracranial extension, particularly in the pterygomaxillary fossa (three cases). Following extensive removal, there were no early recurrences and three late recurrences (9 years and more). In 13 cases with a follow-up period of 1 to 8 years, there were no clinical recurrences. In only two cases was the meningioma totally removed. There were three postoperative deaths, two cases of hemiparesis with aphasia and epilepsy, one case with a frontal lobe syndrome, and nine with slight oculomotor, visual, or esthetic sequelae.
One-stage posterior decompression and reconstruction of the cervical spine by using pedicle screw fixation systems
Authors: Abumi Kuniyoshi , Kaneda Kiyoshi , Shono Yasuhiro , Fujiya Masanori 
Published: May 2009

Object. This retrospective study was conducted to analyze the results of one-stage posterior decompression and reconstruction of the cervical spine by using pedicle screw fixation systems in 46 patients.
Methods. Causes of cervical myelopathy in these 46 patients included spondylosis or ossification of the posterior longitudinal ligament, rheumatoid arthritis, metastatic or primary vertebral tumors, cervical spinal injuries, and spinal cord tumor. Thirty-three patients underwent this one-stage procedure as primary surgery. In the remaining 13 patients who had previously undergone laminectomies, the one-stage procedure was performed as salvage surgery. Cervical pedicle screws were inserted into the pedicles after probing and tapping. Graft bone was placed on the bilateral lateral masses, and pedicle screws were interconnected longitudinally by either plates or rods. Postoperatively, 26 patients showed improved neurological status (at least one grade improvement on Frankel's functional classification). There were no cases of neurological deterioration postoperatively. Solid bony fusion was obtained in all patients, except in seven patients with metastatic tumor who did not receive bone grafts. Correction of kyphosis was satisfactory. Postoperative radiological evaluation revealed that 10 (5.3%) of 190 screws inserted into the cervical vertebrae had perforated the cortex of the pedicles; however, no neurovascular complications were caused by the perforations.
Conclusions. The pedicle screw fixation procedure, which does not require the lamina to be used as a stabilizing anchor, has proven to be valuable when performing one-stage posterior decompressive and reconstructive surgery in the cervical spine. The risk to neurovascular structures in this procedure, however, cannot be completely eliminated. Thorough knowledge of local anatomy and application of established surgical techniques are essential for this procedure.
Lateral exit-zone stenosis and lumbar radiculopathy
Authors: Maher Cormac O. , Henderson Fraser C. 
Published: May 2009

Object. Hypertrophy of the superior facet of the inferior vertebra, resulting in a compression of the nerve root at the lateral foraminal exit, is a recognized cause of radicular symptoms, particularly in patients in whom previous lumbar spine surgery has failed. The lesion-specific presenting symptoms, imaging findings, and surgical treatment of this lesion, however, have received little attention. The authors prospectively studied a series of eight consecutive patients, in whom a diagnosis of lumbar stenosis at the lateral foraminal exit had been made, to elucidate the common presenting signs and symptoms of this disorder, as well as to evaluate the success of the operative treatment.
Methods. The eight patients were selected from a group of 250 consecutive patients who presented to a tertiary-care hospital and in whom a diagnosis of long-standing lumbar radiculopathy had been made. In all cases the diagnosis was confirmed by imaging studies and by intraoperative findings. The authors performed decompressive procedures on the nerve root via a medial facet-sparing approach.
Conclusions. The authors conclude that this lesion presents with characteristic physical findings and on imaging studies that distinguish it from other causes of radiculopathy, and they propose a lesion-specific, facet-sparing surgical technique that has yielded excellent results.
The role of bupivacaine in early postoperative pain control after lumbar decompression
Authors: Chadduck James B. , Sneyd J. Robert , Pobereskin Louis H. 
Published: May 2009

Object. The authors studied the effect of immediate postoperative administration of bupivacaine in patients who underwent a lumbar decompressive procedure.
Methods. In this randomized double-blind trial, 50 patients who underwent elective lumbar decompression after induction of general anesthetic received a postoperative bilateral paravertebral 40-ml intramuscular application of either saline (0.9%) or bupivacaine (0.25%). For delivering morphine, both groups used a patient-controlled analgesia system for 24 hours postsurgery. Pain scores, 10-cm visual analog scale scores, and morphine consumption were similar between groups with no significant differences (p > 0.05).
Conclusions. Results of subgroup analysis suggested strongly that perioperative administration of methylprednisolone in a sustained-release preparation was associated with a reduction in postoperative pain (p < 0.05).
A biomechanical evaluation of occipitocervical instrumentation: screw compared with wire fixation
Authors: Hurlbert R. John , Crawford Neil R. , Choi Won Gyu , Dickman Curtis A. 
Published: May 2009

Object. The purpose of this study was to compare cable techniques used in occipitocervical fixation with two types of screw fixation. The authors hypothesized that screw fixation would provide superior immobilization compared with cable methods.
Methods. Ten cadaveric specimens were prepared for biomechanical analyses by using standard techniques. Angular and linear displacement data were recorded from the occiput to C-6 with infrared optical sensors after conditioning runs. Specimens underwent retesting after fatiguing. Six methods of fixation were analyzed: Steinmann pin with and without C-1 incorporation; Cotrel-Dubousett horseshoe with and without C-1 incorporation; Mayfield loop with C1–2 transarticular screw fixation; and a custom-designed occipitocervical transarticular screw-plate system. Sublaminar techniques were extended to include C-3 in the fusion construct, whereas transarticular techniques incorporated the occiput, C-1, and C-2 only.
All methods of fixation provided significant immobilization in all specimens compared with the nonconstrained destabilized state. Despite incorporation of an additional vertebral segment, sublaminar techniques performed worse as a function of applied load than screw fixation techniques. Following fatiguing, these differences were more pronounced. The sublaminar techniques failed most prominently in flexion—extension and in axial rotation. On gross inspection, increased angular displacement associated with loosening of the sublaminar cables was observed.
Conclusion. Occipitocervical fixation can be performed using a variety of techniques; all bestow significant immobilization compared with the destabilized spine. All methods tested in this study were susceptible to fatigue and loss of reduction and were weakest in resisting vertical settling. Screw fixation of the occiput—C2 reduces the number of vertebral segments that are necessary to incorporate into the fusion construct while providing superior immobilization and resistance to fatigue and vertical settling compared with sublaminar methods.
Stability of the craniovertebral junction after unilateral occipital condyle resection: a biomechanical study
Authors: Vishteh A. Giancarlo , Crawford Neil R. , Melton M. Stephen , Spetzler Robert F. , Sonntag Volker K. H. , Dickman Curtis A. 
Published: May 2009

Object. The authors sought to determine the biomechanics of the occipitoatlantal (occiput [Oc]—C1) and atlantoaxial (C1–2) motion segments after unilateral gradient condylectomy.
Methods. Six human cadaveric specimens (skull with attached upper cervical spine) underwent nondestructive biomechanical testing (physiological loads) during flexion—extension, lateral bending, and axial rotation. Axial translation from tension to compression was also studied across Oc—C2. Each specimen served as its own control and underwent baseline testing in the intact state. The specimens were then tested after progressive unilateral condylectomy (25% resection until completion), which was performed using frameless stereotactic guidance. At Oc—C1 for all motions that were tested, mobility increased significantly compared to baseline after a 50% condylectomy. Flexion—extension, lateral bending, and axial rotation increased 15.3%, 40.8%, and 28.1%, respectively. At C1–2, hypermobility during flexion—extension occurred after a 25% condylectomy, during axial rotation after 75% condylectomy, and during lateral bending after a 100% condylectomy.
Conclusions. Resection of 50% or more of the occipital condyle produces statistically significant hypermobility at Oc—C1. After a 75% resection, the biomechanics of the Oc—C1 and C1–2 motion segments change considerably. Performing fusion of the craniovertebral junction should therefore be considered if half or more of one occipital condyle is resected.