摘要:

&NA;This review article outlines basic concepts and pathophysiological aspects of the chemistry of oxygen free radicals in all forms of brain injury and brain edema. Recent experimental studies have demonstrated that oxygen free radicals may be important mediators of brain injury and brain edema, and pharmacological antagonism of oxygen free radicals shows beneficial therapeutic results. A number of fundamental questions need to be resolved, and advanced techniques for detecting oxygen free radicals will be needed. No clinical data are available, but oxygen free radical scavengers may possibly become a critical therapeutic modality for brain injury and brain edema. (Neurosurgery27:1‐11, 1990)

ISSN:0148-396X    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

&NA;Aneurysms of the posterior inferior cerebellar artery‐vertebral artery complex are relatively uncommon lesions. They include aneurysms at the origin of the posterior inferior cerebellar artery (PICA‐VA), aneurysms on the distal artery (PICA) and aneurysms at the junction of the vertebral and basilar arteries (VA‐BA). We have had the opportunity to treat 17 patients and study the radiological records of 9 additional patients in the past 8 years. The aneurysms ranged in size from 3 to 30 mm, with mean values of 10.6, 7.3,and 9 mm for PICA‐VA lesions, distal PICA lesions, and VA‐BA lesions, respectively. Three of the 4 VA‐BA aneurysms were located at the midline, and the mean distance of the PICA‐VA aneurysms from the midline was 7.6 to 9.4 mm; 2 aneurysms crossed the midline from their parent VA. The aneurysms were located slightly more often on the left side (left:right ratio, 1:2), were found more frequently in women (2.25:1), and occurred at a mean age of 50 years. Ten aneurysms at the origin of the PICA and 4 VA‐BA aneurysms were treated via a lateral suboccipital craniectomy; 3 distal PICA aneurysms were exposed by a midline craniectomy. Surgery was carried out acutely in 5 patients. Tortuousness of the VA required contralateral approaches in 2 patients, an exploratory craniectomy in 1 patient, and an approach toward the dome of 1 patient with a VA‐BA aneurysm. Morbidity was primarily due to cranial nerve dysfunction. There were no perioperative deaths. These aneurysms can easily be missed on initial radiographic examination; one appeared only on the second study, one was seen to grow over 16 days, and one was discovered at the level of C1 extracranially. Our radiographic and surgical approach to the treatment of these lesions is presented. (Neurosurgery27:12‐21, 1990)

ISSN:0148-396X    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

&NA;Since 1978, the authors have seen 14 neonates with vein of Galen malformations who were born with severe congestive heart failure. The 5 infants treated before 1983 underwent craniotomy and clipping of feeding vessels; all died in the perioperative period. Since 1983, 8 neonates have been treated with combined arterial and venous interventional neuroradiological techniques; 6 infants survived. Two‐dimensional echocardiography, color Doppler flow imaging, and pulsed Doppler ultrasound were used to assess blood flow within the malformation before and after staged transluminal embolic procedures were performed. The results of the diagnostic studies and the clinical status of the infants were used to evaluate the success of embolic therapy and the need for further neuroradiological intervention. (Neurosurgery27:22‐28, 1990)

ISSN:0148-396X    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

&NA;The efficacy of the 21‐aminosteroid U74006F was investigated using different dosages in a restricted, randomized, placebo‐controlled trial. Forty cynomolgous monkeys were divided into five groups of eight. There were two groups given treatment with placebos, one being saline and the other the vehicle in which U74006F was delivered. There were three U74006F treatment dosage groups: 0.3, 1.0, and 3.0 mg/kg. Each monkey underwent baseline cerebral angiography followed by right‐sided craniectomy and subarachnoid placement of a clot around the middle cerebral artery (MCA). Treatment was administered intravenously every 8 hours for 6 days. Seven days after experimental subarachnoid hemorrhage, angiography was repeated, and the animals were killed. In both saline or vehicle placebo treatment groups, significant vasospasm (VSP) occurred on the clot side in the extradural internal carotid artery (C3), the intradural internal carotid artery, the precommunicating segment of the anterior cerebral artery (A1,) and the MCA (P< 0.01). After U74006F treatment, significantly less VSP developed in the A1on the clot side (0.3 mg/kg U74006F treatment group) and the MCA (all U74006F treatment groups,P< 0.05). When the percentages of change from the baseline for the vessel diameters on the clot side were compared, VSP was attenuated in the A1(P< 0.05) and MCA (P< 0.001) of all U74006F treatment groups as compared with the placebo treatment groups. Only 0.3 mg/kg of U74006F significantly prevented VSP in C3(P< 0.01). Although the 0.3 mg/kg dosage appeared to have the most favorable effect, no significant differences were observed among the three dosage groups. Electron microscopy of the MCA on the clot side in the animals treated with U74006F still showed luminal convolutions and morphological changes in the endothelial cells. These changes appeared less prominent in those MCAs with milder VSP. If these results in primates are applicable to humans, U74006F would be useful in reducing VSP after aneurysmal subarachnoid hemorrhage. (Neurosurgery27:29‐38, 1990)

ISSN:0148-396X    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

&NA;The effects of intraventricularly administered atrial natriuretic peptide (ANP) on the brain water, sodium, and potassium contents in ischemic brain edema were investigated. By use of a three‐vessel occlusion model, ischemic brain edema was produced in the rat brain by 15 minutes of global ischemia followed by recirculation. Water content was measured by means of a drying/weighing method; sodium and potassium contents were measured by means of flame photometry. The effects of intraventricular administration of ANP were evaluated by a comparison between the groups given 2 and 5 &mgr;g of atriopeptin II (treated) and those given 0.9% NaC1 (sham‐treated). The treated groups showed significant decreases in brain water (P< 0.02) and sodium (P< 0.01) contents at 15 and 30 minutes after recirculation, whereas the brain potassium contents remained unaltered. Before ischemia and immediately after 15 minutes of ischemia, intraventricularly administered ANP did not significantly change the brain water, sodium, or potassium contents. There was no significant difference in the effect on the amount of brain water and sodium between the two doses (2 and 5 &mgr;g). These effects of ANP were thought not to be mediated by primary changes in serum osmolality and sodium and potassium concentrations, because intraventricular administration of ANP did not change them significantly. The present results reveal that, in ischemic brain edema. ANP may act directly on the central nervous system to inhibit brain water and sodium accumulation. (Neurosurgery27:39‐44, 1990)

ISSN:0148-396X    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

&NA;The authors reviewed the computed tomographic (CT) scans of patients with subarachnoid hemorrhage whose initial angiograms were negative, to investigate the validity of CT scans in predicting the presence of an angiographically missed aneurysm in such patients. During the past 14 years, additional angiograms have been obtained for 38 of the 45 patients with subarachnoid hemorrhage whose initial angiograms disclosed no aneurysm. Aneurysms were found in 8 patients; 7 on the anterior communicating artery and 1 at the junction of the internal carotid and posterior communicating arteries. CT scans were taken within 4 days after subarachnoid hemorrhage in 31 patients. Analysis of these scans showed that the second angiogram revealed 1) an aneurysm in 21% of the patients with a thin layer of subarachnoid blood and in 63% of those with a thick layer; 2) no aneurysm in the patients without subarachnoid blood; and 3) an aneurysm of the anterior communicating artery in 70% of the patients who showed a considerable amount of blood in the basal frontal interhemispheric fissure. These results suggest that if CT scans show thin or thick subarachnoid blood, angiographic study should be repeated early in the course. If a considerable amount of blood is shown in the basal frontal interhemispheric fissure, it is highly probable that an aneurysm is hidden on the anterior communicating artery, even if the angiogram is negative for an aneurysm. (Neurosurgery27:45‐51, 1990)

ISSN:0148-396X    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

&NA;Recent experimental work has suggested that the adrenergic nervous system is important in regulating cerebral blood flow under conditions of hypoxia and systemic arterial hypertension. Although previous investigations have demonstrated the presence of adrenergic neurons adjacent to human cerebral vessels, the nature of adrenergic receptors on human cerebral blood vessels remains poorly defined. The present study was performed to characterize adrenergic reception on membranes prepared from human pia, a rich source of small blood vessels, using radioligand binding techniques. Adrenergic membrane receptors were characterized using the binding of [3H]dihydroalprenolol for the &bgr; subtypes and [3H]prazosin and [3H]yohimbine for the &agr; subtypes. Displaceable binding was demonstrated with each agent. A small series of adrenergic agents competed for the [3H]dihydroalprenolol, [3H]yohimbine, and [3H]praz binding sites in a fashion suggesting the presence of &agr;1‐, &agr;2‐, &bgr;1and &bgr;2‐receptors on the vessels within human pia. (Neurosurgery27:52‐59, 1990)

ISSN:0148-396X    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

&NA;Eleven patients who experienced significant loss of vision after transsphenoidal surgery are reported on. The mechanisms involved in these visual complications include direct injury or devascularization of the optic apparatus, fracture of the orbit, postoperative hematoma, cerebral vasospasm, and prolapse of the optic chiasm into an empty sella. Factors that may increase the risk of visual complications include the presence of a pituitary macroadenoma, previous visual impairment, a “bottleneck” or dumbbell‐shaped tumor, previous surgery and/or radiation therapy, and, possibly, use of a lumbar subarachnoid catheter during operation. A practical approach to the management and avoidance of these complications is presented. (Neurosurgery27:60‐68, 1990)

ISSN:0148-396X    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

&NA;Cotrel‐Dubousset instrumentation (CDI) was introduced in 1984 primarily for the treatment of scoliosis. The applications of this unique and versatile system have expanded to other diseases of the spine. Thoracolumbar fractures are a common management problem for which the device seems to be well suited. We review our results of 15 patients with unstable thoracolumbar fractures treated with CDI at an average of 24 months‘ follow‐up. The results are promising and compare favorably with other forms of surgical and medical management. Postoperatively, there was a loss of 2° in the angle of deformity and 0.9 mm of vertebral body displacement. Incomplete neurological injuries improved one or more Frankel grades in 75% of our patients. There were three complications (20%). CDI offers theoretical advantages over Harrington instrumentation and conservative (nonoperative) management. The use of CDI in the treatment of unstable thoracolumbar fractures is endorsed by these results. (Neurosurgery27:69‐73, 1990)

ISSN:0148-396X    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

&NA;Twenty‐three patients with malignant glial neoplasms were treated with anticoagulant therapy for thromboembolic complications. Fifteen patients had deep vein thrombosis alone, and 8 patients had both deep vein thrombosis and pulmonary embolism. Serum prothrombin times were maintained at 1.25 times control for an average of 5.8 months per patient, for a total patient exposure to warfarin therapy of 132 patient‐months (11 patient‐years). Only 1 patient suffered a recurrent pulmonary embolism, and this occurred during an episode of gastrointestinal bleeding, when anticoagulant therapy had to be discontinued prematurely. All patients were followed with serial computed tomographic or magnetic resonance imaging scans, and no patient showed radiographic evidence of intratumoral hemorrhage either during or after warfarin therapy. One patient, who died from a large recurrent glioblastoma, was found at autopsy to have scattered foci of intratumoral hemorrhage. This series, together with a review of the available literature, suggests that oral anticoagulant therapy is both a safe and effective means of treating thromboembolic complications in patients with residual malignant glial tumors. (Neurosurgery27:74‐77, 1990)

ISSN:0148-396X    

出版商:OVID    

年代:1990

数据来源: OVID