bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surgical therapy for medically intractable epilepsy
Authors: Ojemann George A. 
Published: May 2009

✓ There has been a recent renewal of interest in surgical therapy for medically intractable epilepsies. Cortical resection and callosotomy are the most widely accepted modes of surgical management. The indications for each of these approaches are reviewed. Although there has been much interest in imaging techniques, including positron emission tomography, to identify epileptogenic zones, identification still depends primarily on the electroencephalogram (EEG). There are several approaches to the evaluation and intraoperative management of patients undergoing cortical resection for temporal lobe epileptogenic zones. These range from selection based on scalp interictal EEG criteria, with resections guided by electrocorticography and functional mapping, to selection based on the location of ictal onset as recorded by chronically implanted depth electrodes, with an anatomically standard resection of the temporal lobe or resection limited to amygdalohippocampectomy. No one approach provides the optimum balance of benefits to risks and costs for all patients.
The relative value of the different approaches for various populations of patients with medically intractable partial complex seizures is reviewed. Techniques for minimizing the morbidity of these operations, especially in regard to language and memory, are also discussed, as are the contributions to an understanding of the neurobiology of human epilepsy and human higher functions derived from the surgical therapy of epilepsy.
Effect of stimulation of the medullary reticular formation on cerebral vasomotor tonus and intracranial pressure
Authors: Nagao Seigo , Nishiura Tsukasa , Kuyama Hideyuki , Suga Masakazu , Murota Takenobu 
Published: May 2009

✓ The authors report the results of a study to evaluate the effect of stimulation of the medullary reticular formation on cerebral vasomotor tonus and intracranial pressure (ICP) after the hypothalamic dorsomedial nucleus and midbrain reticular formation were destroyed. Systemic arterial pressure (BP), ICP, and local cerebral blood volume (CBV) were continuously recorded in 32 cats. To assess the changes in the cerebral vasomotor tonus, the vasomotor index defined by the increase in ICP per unit change in BP was calculated. In 29 of the 32 animals, BP, ICP, and CBV increased simultaneously immediately after stimulation. The increase in ICP was not secondary to the increase in BP, because the vasomotor index during stimulation was significantly higher than the vasomotor index after administration of angiotensin II. The vasomotor index was high during stimulation of the area around the nucleus reticularis parvocellularis. In animals with the spinal cord transected at the C-2 vertebral level, ICP increased without a change in BP.
These findings indicate that the areas stimulated in the medullary reticular formation play an important role in decreasing cerebral vasomotor tonus. This effect was not influenced by bilateral superior cervical ganglionectomy, indicating that there is an intrinsic neural pathway that regulates cerebral vasomotor tonus directly. In three animals, marked biphasic or progressive increases in ICP up to 100 mm Hg were evoked by stimulation. The reduction of cerebral vasomotor tonus and concomitant vasopressor response induced by stimulation of the medullary reticular formation may be one of the causes of acute brain swelling.
The surgical treatment of childhood moyamoya disease
Authors: Olds Meredith V. , Griebel Robert W. , Hoffman Harold J. , Craven Marilyn , Chuang Sylvester , Schutz Hart 
Published: May 2009

✓Moyamoya disease is a progressive disorder, predominantly seen in childhood, that can cause severe permanent disability. The search for effective treatment has largely been unsuccessful in the past, but recent efforts at surgical intervention have shown promising results.
The natural history of moyamoya disease, the options for treatment, and a series of patients from the Hospital for Sick Children in Toronto are reviewed. The results of surgical treatment are encouraging and the authors believe that it should be offered to all pediatric patients in the progressive stage of the disease.
Perioperative antibiotic prophylaxis for prevention of postoperative neurosurgical infections
Authors: Young Ronald F. , Lawner Pablo M. 
Published: May 2009

✓ The authors report the results of a randomized, prospective study to assess the effectiveness of perioperative antibiotic prophylaxis in preventing postoperative infections following clean neurosurgical operations. The study group comprised 846 patients treated between October, 1979, and June, 1984. Antibiotics, including cefazolin and gentamicin, were administered only in the immediate preoperative and intraoperative periods. Sixteen patients, none of whom developed infections, were excluded from final statistical analysis because they had inadvertently been entered into the study while failing to meet entry criteria. Fifteen wound infections (3.64%) developed in the group of 412 patients who did not receive antibiotics, whereas only four infections (0.96%) were identified among the 418 patients who received antibiotics. The difference is statistically significant (p = 0.008) and represents a 74% reduction in infection rate with antibiotics. An analysis of subgroups of surgical procedures revealed a dramatic decrease in craniotomy infections from 6.77% to 0% (p = 0.003). Of the four infections that occurred among the antibiotic-treated patients, three were in cases where foreign bodies had been implanted.
No complications of antibiotic usage were identified. The rates of infection in areas of the body other than the surgical wound were no different in the antibiotic-treated and nontreated groups. All wound infections in both antibiotic-treated and nontreated patients involved similar types of Gram-positive organisms, suggesting that antibiotic prophylaxis did not produce infections with resistant or unusual organisms. This study, combined with other recently published analyses, suggests that routine perioperative antibiotic prophylaxis can significantly reduce the incidence of postoperative neurosurgical infections.
Choroid plexus tumors: problems in diagnosis and management
Authors: Boyd Michael C. , Steinbok Paul 
Published: May 2009

✓ Choroid plexus tumors are uncommon neoplasms of the central nervous system. A series of 11 cases from the Vancouver General and British Columbia Children's Hospitals, treated during the last 12 years, are reviewed. Some of the management problems commonly encountered with these tumors are discussed. Many of these tumors are associated with severe hydrocephalus at the time of diagnosis, and the perioperative management of this hydrocephalus remains a matter of some debate. The timing of and the necessity for shunting are major considerations. Large subdural fluid collections are often discovered in the postoperative period, and these occasionally cause symptoms of increased intracranial pressure. Reasons for this problem are suggested and possible steps for its prevention are proposed.
The similarity between papillary ependymomas and choroid plexus papillomas has sometimes caused difficulty in pathological diagnosis. Choroid plexus carcinomas, of which there were two in this series, also present a diagnostic challenge. Differential diagnosis affects the further treatment and prognosis for the patient.
Cerebral hyperperfusion following carotid endarterectomy
Authors: Schroeder Torben , Sillesen Henrik , Sørensen Ole , Engell Hans Christian 
Published: May 2009

✓ Serial measurements of cerebral blood flow (CBF) were performed in 56 patients before and one to four times after uncomplicated carotid endarterectomy. The findings were related to the ratio between internal carotid artery (ICA) and common carotid artery (CCA) mean pressures.
Within the 1st postoperative day CBF increased by a median of 37% in the ipsilateral and 33% in the contralateral hemisphere. Later recordings showed a gradual return of CBF toward the preoperative level. Sixteen patients with an ICA/CCA pressure ratio below 0.7 showed a significantly more pronounced and longer-lasting flow increase than did 40 patients with a ratio above this level. On Day 1, the median CBF increase in the ipsilateral hemisphere was 61% and 24% in the two groups, respectively (p < 0.01). A significant improvement in side-to-side asymmetry, resulting from a higher gain in the ipsilateral hemisphere, occurred in the low pressure ratio group, while the hemispheric asymmetry on average was unchanged in the high pressure ratio group. This relative hyperemia was most pronounced 2 to 4 days following reconstruction.
The marked hyperemia, absolute as well as relative, in patients with a low ICA/CCA pressure ratio suggests a temporary impairment of autoregulation. Special care should be taken to avoid postoperative hypertension in such patients, who typically have preoperative hypoperfusion, to avoid the occurrence of cerebral edema or hemorrhage.
Potent and specific killing of human malignant brain tumor cells by an anti-transferrin receptor antibody-ricin immunotoxin
Authors: Zovickian John , Johnson Virginia Gray , Youle Richard J. 
Published: May 2009

✓ Immunotoxins are hybrid molecules which combine the exquisite selectivity of monoclonal antibodies with the potent toxicity of protein toxins. An immunotoxin was constructed by linking a murine monoclonal antibody against the human transferrin receptor (TR) to the plant toxin, ricin.
The cytotoxic activity of the anti-TR-ricin immunotoxin was tested in vitro and demonstrated highly potent and cell type-specific killing of cells derived from human glioblastoma, medulloblastoma, and leukemia. The anti-TR-ricin immunotoxin killed more than 50% of “target” cells at a concentration of 5.6 × 10−13 M after an 18-hour incubation with the ionophore, monensin. This potency exceeds that of any other anti-TR immunotoxin reported in the literature. When the activity of the anti-TR-ricin immunotoxin against “target” tumor-derived cells was compared with the immunotoxin's activity against “non-target” cells, it could be predicted that a selective toxicity of anti-TR-ricin immunotoxin between tumor cells and normal brain was more than 150- to 1380-fold. Solid-phase indirect radioimmunoassay techniques were used to demonstrate significantly higher levels of TR in the glioblastoma- and medulloblastoma-derived cell lines, as well as in surgical tissue samples of medulloblastoma and glioblastoma, as compared to normal brain.
Immunotoxins targeted to the TR may possess sufficient specificity to be of therapeutic importance, particularly to treat neoplastic disease of the central nervous system involving compartments (such as intrathecal, intraventricular, or cystic) where delivery of immunotoxins to tumor would not require transvascular transport.
Transmission characteristics of pulse waves in the intracranial cavity of dogs
Authors: Kasuga Yoichiro , Nagai Hajime , Hasegawa Yasuhiro , Nitta Masahiro 
Published: May 2009

✓ Systems analysis of intracranial pressure pulse waveforms was carried out in six dogs under conditions of normocapnia and intracranial normotension to determine how the pressure pulse is transmitted through the intracranial cavity. Since the intracranial cavity can be regarded as a system, systems analysis was applied to it. The pressure pulse wave of the common carotid artery was used as the input signal and the epidural pressure pulse wave as the output signal. An attempt was made to randomize the input signal using a cardiac pacemaker or an aorta balloon. The transfer function of the system was estimated numerically from the autocorrelation function of the input signal and the cross-correlation function of the input and output signals by means of the least-squares method.
Some characteristics of pressure transmission through the system were observed. The gain curve of the system decreased between 1 and 7 Hz, then suddenly increased to form a marked peak at about 10 to 15 Hz, where the phase curve also changed from positive to negative. These results suggest that the lower frequencies of the pulse wave were suppressed during transmission through the intracranial cavity, whereas the greatest acceleration in transmission occurred at about 10 to 15 Hz. In addition, resonance was evident in the intracranial cavity under normal intracranial conditions. This is the first report of such resonance.
Neoadjuvant chemotherapy for newly diagnosed germ-cell tumors of the central nervous system
Authors: Allen Jeffrey C. , Kim Jae Ho , Packer Roger J. 
Published: May 2009

✓ A neoadjuvant (preradiotherapy) chemotherapy regimen consisting of either cyclophosphamide alone (60 to 80 mg/kg) or a modified multidrug regimen (vinblastine, bleomycin, cyclophosphamide, and cisplatin) was administered to 15 newly diagnosed patients with histologically confirmed, fully staged, primary germ-cell tumors (GCT's) of the central nervous system (CNS). There were 11 patients with germinomas and four with non-germinoma malignant GCT's. There were six females and nine males, whose median age was 13 years (range 4 months to 24 years). Seven germinoma patients (64%) had disseminated disease. For the germinoma patients, the subsequent radiotherapy dose was modified based on the response to the neoadjuvant chemotherapy, and craniospinal radiotherapy was given only to those with disseminated CNS disease at diagnosis. Ten of the 11 germinoma patients had complete disappearance of all evaluable disease after two courses of chemotherapy (cyclophosphamide in eight and multidrug in three) and one had a partial response. The planned dose of radiotherapy to the primary tumor was reduced from 5500 to 3000 rads, and the craniospinal dose was lowered from 3600 to 2000 rads. Ten patients remain in continuous disease-free remission 20+ to 89+ months after diagnosis (median follow-up period 47 months). All four patients with non-germinoma GCT's received the multidrug regimen, and two of three patients with evaluable disease had a partial response. High-dose regional and craniospinal radiotherapy was administered thereafter, but only two patients remain in their first remission.Previously untreated germinoma is a highly chemosensitive disease and the neoadjuvant treatment strategy permits the identification of active chemotherapy regimens in newly diagnosed patients. Patients who have complete responses to neoadjuvant chemotherapy tolerate a significant radiotherapy dose reduction without compromising long-term survival, thereby allowing a reduction of some of the late effects of therapeutic radiation. Germinomas tend to disseminate early in the course of the disease and a pre-therapy staging evaluation permits individualized radiotherapy treatment planning.
Cochlear nerve injuries caused by cerebellopontine angle manipulations
Authors: Sekiya Tetsuji , Møller Aage R. 
Published: May 2009

✓ Changes in the response from the cochlear nerve in dogs resulting from cerebellopontine angle (CPA) manipulations were correlated with histological changes in the nerve. The aim of this study was to determine the mechanisms underlying hearing deficits incurred as a result of manipulations in the CPA. Compound action potentials (CAP) were recorded from the cochlear nerve in response to click stimulation before, during, and after cerebellar and eighth nerve retractions were performed under anesthesia. The retractions were carried out to elicit different degrees of change in the latency and waveform of the CAP. About 30 minutes after completion of the manipulations, the dogs were perfused with a fixative and their cochlear nerves and brain stems were prepared for histological studies. The results showed that retraction of the eighth nerve caused a disintegration of the myelin sheath, and there were multiple and extensive foci of petechial hemorrhage and thromboses of the vasa nervorum of the cochlear nerve.
In two dogs in which retraction was carried to a point at which the N2 peak of the CAP was abruptly obliterated, there was a separation of the central and peripheral myelin junction (Obersteiner-Redlich (OR) zone) and bleeding from the vasa nervorum at the OR zone. In the dogs in which the changes in the CAP had almost recovered before fixative perfusion, there were petechial hemorrhages within the cochlear nerve trunk, thus showing that improvement of electrophysiological responses may not always correlate with the absence of morphological changes.
Alpha-1-antitrypsin in human brain tumors
Authors: Sawaya Raymond , Zuccarello Mario , Highsmith Robert 
Published: May 2009

✓ This study was undertaken to confirm the presence of alpha-1-antitrypsin (α1-AT) in human brain tumors and to attempt to elucidate its significance. Seventy-seven consecutive unselected patients with various brain tumors were entered in this study. Theα1-AT andα2-macroglobulin contents of the tumor extracts were qualitatively assessed by Ouchterlony immunodiffusion techniques. Plasminogen activator (PA) activity was assayed electrophoretically on sodium dodecyl sulfate gels. The patients were divided into two groups according to the positivity of their tumors toα1-AT. Sixty-eight percent of the tumors were positive forα1-AT, and all specimens were negative forα2-macroglobulin. Clinical and biological parameters obtained in all study patients failed to show statistically significant differences between the two groups with the exception of PA activity (p = 0.001), the peritumoral edema as seen on computerized tomography, and the preoperative serum fibrinogen level. These three parameters were higher in the group with specimens positive toα1-AT.This study supports the hypothesis thatα1-AT is produced primarily by tumor cells in proportion to the regional proteolytic and inflammatory activity, and may protect the tumor cells.
Subtemporal-preauricular infratemporal fossa approach to large lateral and posterior cranial base neoplasms
Authors: Sekhar Laligam N. , Schramm Victor L. , Jones Neil F. 
Published: May 2009

✓ A subtemporal-preauricular infratemporal fossa approach to remove 22 large neoplasms involving the lateral and posterior cranial base is detailed. The areas from which a neoplasm could be removed by this approach included the sphenoid and clival bone; the medial half of the petrous temporal bone; the infratemporal fossa; the nasopharynx; the retro- and parapharyngeal area; the ethmoid, sphenoid, and maxillary sinuses; and the intradural clivus-foramen magnum area. The pathology of the neoplasms included benign tumors such as meningioma, malignant cartilaginous neoplasms such as chordoma, and other malignant lesions such as nasopharyngeal carcinoma. This approach offers many advantages over other anterior and lateral approaches to the lateral and posterior cranial base: these include minimal brain retraction; direct access to the ipsilateral petrous and upper cervical internal carotid artery; reconstruction of extensive cranial base defects, often with the use of a vascularized rectus abdominis flap; preservation of the hearing conduction mechanism when it is not involved by tumor; and the maintenance of excellent facial nerve function postoperatively.
The use of an anterior extradural approach (transethmoidal) and of an intradural approach (frontotemporal or retromastoid), either concurrently or separately, is necessary in some patients to effect total tumor removal. The most serious complication in this series was the death of a patient due to postoperative infection and bilateral carotid artery rupture, which may have been avoided by the use of a rectus abdominis muscle flap for reconstruction. Among the 21 surviving patients, 18 had a good outcome, two had a fair outcome, and one with preexisting neurological deficits had a poor outcome. One of the surviving patients with a chordoma died of pulmonary metastases 1 year later, without evidence of local recurrence. The length of postoperative follow-up evaluation in these patients is insufficient to make any judgment about the effectiveness of this surgical approach in achieving a cure or long-term control of the tumors described.
Adjuvant high-dose photoradiation therapy in the treatment of cerebral glioma: a Phase 1–2 study
Authors: Kaye Andrew H. , Morstyn George , Brownbill David 
Published: May 2009

✓ A Phase 1–2 study of high-dose photoradiation therapy was performed in 23 patients with cerebral tumors. Twenty-two patients had high-grade gliomas (13 glioblastomas, six recurrent glioblastomas, two anaplastic astrocytomas, and one recurrent anaplastic astrocytoma) and one had a right frontal metastasis from a carcinoma of the lung. Hematoporphyrin derivative was administered to these patients in a dose of 5 mg/kg and, 24 hours later, they all underwent a craniotomy with radical excision of the tumor. The tumor bed was then irradiated with 630 nm of laser light from either an argon dye laser or a gold metal vapor laser for between 43 and 94 minutes, receiving total doses of 70 to 120 J/sq cm (six cases) or 120 to 230 J/sq cm (17 cases). The temperature of the tumor bed was kept below 37°C by irrigation. Fifteen patients who developed new tumors underwent postoperative radiotherapy (45 Gy in 20 divided doses).
There was no evidence of increased cerebral edema and no other toxicity from the therapy. All patients were discharged from the hospital within 18 days of surgery. Four of seven patients with gliomas have suffered a further recurrence at 12 to 16 weeks, and two of 15 patients with primarily treated gliomas experienced recurrence at 3 and 13 months following therapy. Fifteen patients have had no recurrence of their tumor and are alive and well at a median follow-up period of 7 months (range 1 to 16 months). It is concluded that photoradiation therapy using 5 mg/kg of hematoporphyrin derivative and 630 nm light at doses of up to 230 J/sq cm can be used as an adjuvant to surgery and radiotherapy with no additional complications.
Effect of hypoxia on the contractile response to KCl, prostaglandin F2α, and hemoglobin
Authors: Nakagomi Tadayoshi , Kassell Neal F. , Sasaki Tomio , Fujiwara Shigeru , Lehman R. Michael , Johshita Hiroo , Torner James C. 
Published: May 2009

✓ The purpose of this experiment was to evaluate the effect of hypoxia on thein vitrocontractile responses of canine basilar artery to KCl, prostaglandin (PG) F2α, and hemoglobin. Hypoxia was induced by changing the bubbling gas mixture in the chamber from 95% O2/5% CO2to 95% N2/5% CO2. Hypoxia augmented the contractile response developed at 95% O2to 25 mM and 50 mM KCl, 3 × 10−7M and 10−5M PGF2α, and 10−6M hemoglobin. No significant alteration of the hypoxic augmentation in any preparation exposed to 25 mM KCl, 3 × 10−7M PGF2α, or 10−6M hemoglobin was observed with guanethidine (10−5M), prazosin (10−5M), methysergide (10−5M), or diphenhydramine (10−5M).Endothelial denudation did not affect hypoxic augmentation. Hypoxia did not cause any alteration of the contractile response to 10−6M PGF2αin Ca++-free media. Pretreatment with a calcium channel blocker, nicardipine, significantly inhibited the hypoxic potentiation of the contractile response to 25 mM KCl, 3 × 10−7M PGF2α, and 10−6M hemoglobin.These results suggest that hypoxia augments the contractile response to these agonists by a direct action on the smooth-muscle cells, facilitating the transmembrane influx of extracellular calcium. Hypoxia of smooth-muscle cells in the major cerebral arteries might be involved in the pathogenesis of vasospasm.