摘要:

&NA;A subarachnoid hemorrhage was induced in 30 cynomolgus monkeys by the placement of a 6‐ to 7‐ml blood clot through a frontotemporal craniectomy (Day 0). The monkeys underwent a 1‐week‐long, randomized, blind trial comparing various doses of nimodipine to placebo, sham, and no treatment. The treatment groups were: nimodipine, 3 mg/kg every 8 hours (n = 6),6 mg/kg every 8 hours (n = 6), and 12 mg/kg every 8 hours (n = 6); placebo (polyethylene glycol 400), 0.33 ml/kg every 8 hours (n = 6) and no treatment (n = 6). An additional sham group underwent craniectomy without clot placement (n = 6) so that 36 animals in total were operated upon. Differences in cardiopulmonary indices between Day 0 and Day 7 were compared within and between groups. No significant differences were obtained in the sham and no treatment groups. The nimodipine 6‐and 12‐mg/kg groups showed significant decreases in blood pressure (P< 0.04 andP< 0.015). Systemic vascular resistance was increased in the placebo and 3‐mg/kg groups (P< 0.02) and decreased in the 12‐mg/kg group (P< 0.015). Stroke index was increased in the 12‐mg/kg group (P< 0.05). Cardiac index and stroke index correlated positively with nimodipine dosage (r = 0.99,P< 0.05). There were no pronounced changes in pulmonary artery wedge pressure, central venous pressure, alveolar‐arterial oxygen pressure difference, arteriovenous oxygen content difference, and percentage of shunting. (Neurosurgery18:261‐265, 1986)

ISSN:0148-396X    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

&NA;Sciatic nerves of rats were severed with steel scalpel blades and subsequently anastomosed with epineurial sutures and laser‐aided techniques. Morphometric analysis of myelinated nerve fibers proximal and distal to the anastomosed region revealed that the laser had no deleterious effects on the degree of retrograde axonal degeneration or regeneration potential as compared to the traditional suture technique. Although no significant difference in myelinated nerve fiber population was evident between the two methods, future experimentation with various laser parameters might lead to more effective use of lasers in nerve repair. (Neurosurgery18:266‐269, 1986)

ISSN:0148-396X    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

&NA;The left middle cerebral artery and both carotid arteries of 17 cats were occluded to evaluate the effects of oxygenated fluorocarbon emulsion on brain ischemia. Carotid and middle cerebral arteries were occluded concurrently for 2 hours, followed by occlusion of the middle cerebral artery only for another 24 hours. Six animals were treated with oxygenated fluorocarbon emulsion delivered by ventriculocisternal perfusion, 5 received ventriculocisternal perfusion with mock cerebrospinal fluid, and 6 were untreated. Perfusions were started 3 hours after the initial ischemic insult. Infarct size judged by tetrazolium staining and standard neuropathological stains was significantly smaller in the treated animals. The mechanism of protection is as yet unknown, but most likely reflects oxygen/nutrient diffusion into the ischemic middle cerebral artery zone from the ventricular fluorocarbon, or removal of harmful metabolites. The results imply that ventriculocisternal perfusion with fluorocarbon emulsion can preserve neuronal function during a major cerebral vessel occlusion. In the cat, therapy is effective if begun within 3 hours after ischemia starts. (Neurosurgery18, 270‐276, 1986)

ISSN:0148-396X    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

&NA;Reactions of pial arteries and veins as well as intracranial pressure (ICP) and mean arterial pressure during intravenous administration of methohexital were observed in two groups of cats totaling 24 animals in order to investigate hypothesized direct barbiturate effects on cerebral vascular volume. Group 1 had bolus injection of 1 mg/kg followed by infusion of 0.1 mg/kg/min over 60 minutes. This induced a 6 to 7% arterial dilatation at 50 to 60 minutes (not significant); a 20% reduction of pial vein calibers was observed (P< 0.01). In Group 2, the same treatment protocol administered under conditions of ICP elevation to 20 mm Hg by the cisternal infusion of mock cerebrospinal fluid resulted again in consistent, although less extensive, venous caliber reduction (5 to 7%,P< 0.01). In Group 2 controls, pial arteries dilated by 15 to 20%; this reaction was suppressed in the methohexital‐treated animals. After stopping methohexital, however, arteries in the methohexital group dilated to almost the same extent as in controls. Mean arterial pressure remained stable in both groups. ICP was not reduced by methohexital. EEG‐activity was slightly increased during treatment. We conclude that methohexital has a direct effect on vessel caliber and thus cerebral blood volume via absolute diminution of venous vessels and suppression of ICP‐induced autoregulative arterial dilatation. This direct vascular effect, however, seems to be counterbalanced by unknown intracranial mass effects that prevent a reduction in ICP. (Neurosurgery18:277‐282, 1986)

ISSN:0148-396X    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

&NA;The risk of carotid endarterectomy in acute cerebral ischemic situations is well documented. By using the superficial temporal or occipital artery, it is possible to provide relatively low flow revascularization conduits, potentially avoiding the risk of postoperative hemorrhage. Eighteen patients at The University of Texas Health Science Center at Dallas, Texas, have been treated recently with extracranial to intracranial bypass in the setting of acute neurological deficit, stroke in evolution, or recent completed infarction. Angiographic causes of these deficits included cervical carotid occlusion in 5 patients, carotid siphon disease in 2 patients, middle cerebral stenosis or occlusion in 3 patients, and delayed cerebral ischemia following subarachnoid hemorrhage in 8 patients. Neurological improvement was demonstrated within 24 hours following revascularization in 15 cases (83%); 3 patients were unchanged following bypass, and no patient's condition was worsened. The only case of postoperative intracerebral hemorrhage occurred 1 week following a long saphenous vein graft from the subclavian to the middle cerebral artery. After an average follow‐up of 19 months, 7 patients are neurologically normal, 8 patients have mild to moderate deficits, and 3 patients have died. Low flow revascularization procedures appear to be safe in the setting of acute cerebral ischemia and may in selected patients boost regional cerebral blood flow from levels of symptomatic ischemia into a range compatible with normal neuronal function. (Neurosurgery18:283‐291, 1986)

ISSN:0148-396X    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

&NA;A series of 125 adult rats was operated upon to perform end‐to‐end anastomosis of the femoral artery using either a carbon dioxide laser or conventional suture technique. Vessels were inspected at varying time intervals grossly and microscopically. Overall, the rate of aneurysm formation for the laser group was 18.6% (21/113). Late aneurysm formation (1 week or longer after operation) was seen in 29.8% (20/67) of the laser group. No aneurysms were noted in the suture group either early or late. Histological examination of the laser‐joined vessels revealed widespread necrosis and loss of elastic elements in the media. In time, abnormal spindle‐shaped cells appeared in this damaged layer. Histologically, the aneurysms were indistinguishable from those reported in human cerebral aneurysm cases. This technique provides an experimental aneurysm model and lends support to the acquired/degenerative theory of human cerebral aneurysm formation. (Neurosurgery18:292‐299, 1986)

ISSN:0148-396X    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

&NA;Occipital lobe infarction caused by tentorial herniation was described based on computed tomography findings in nine patients. The whole area of the occipital lobe was involved in five patients; some areas were spared in the others. Infarction other than the ipsilateral occipital lobe was seen in four areas of nine patients: the ispsilateral posterior limb of the internal capsule, contralateral Ammon's horn, and two contralateral occipital lobes. Hemorrhagic infarction was seen in two patients. (Neurosurgery18:300‐305, 1986)

ISSN:0148-396X    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

&NA;The authors present a retrospective analysis of 128 cases of odontoid process injury treated at the University of Minnesota and affiliated hospitals between the years 1967 and 1983. Of these 128 cases, 110 were acute fractures, while 18 patients suffered from old, unstable odontoid injuries. Motor vehicle accident was the leading cause of injury, and the largest group of patients was in their second decade. Type II fractures were the most commonly encountered type of injury, and anterior subluxation was the most common displacement. Posterior subluxation, however, had the highest incidence of associated neurological deficit. Regarding treatment, the 110 acute fracture patients fell into the following groups: 16 patients died during the acute phase, 14 patients underwent early posterior cervical fusion, and 80 patients underwent a course of external skeletal fixation. The remaining 18 patients with old unstable injuries underwent posterior cervical fusion. An analysis of the results in these groups led to the elucidation of certain factors that likely are important in determining the treatment of each individual patient. These factors include age of the patient, type of odontoid fracture, direction and degree of fracture displacement, and diagnostic delay. Fracture reduction and halo immobilization are the treatments preferred for patients who are diagnosed within 1 week of injury, who are less than 65 years of age and who have anteriorly, nondisplaced, or minimally posteriorly subluxed (<2 mm) Type II fractures, or who have any Type III injury. In contrast, posterior cervical fusion should be considered seriously in those patients over 65 years of age with Type II fractures or with posterior subluxations greater than 3 mm, in patients with diagnosis later than 7 days after injury, and especially in patients who have suffered redislocation while undergoing a closed form of management. (Neurosurgery18:306‐310, 1986)

ISSN:0148-396X    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

&NA;The neurosurgical role in rehabilitation rehabilitation was studied. Over a 5‐year period, 850 individuals were referred to a rehabilitation center after initial acute care. Surgery was indicated for 66 patients. There were 28 quadriplegic or paraplegic individuals with intractable spasticity. Percutaneous radiofrequency foramenal rhizotomies were found to be 98% effective in relieving posttraumatic spasticity. In 14 patients with cognitive impairment, intellectual improvement had reached a plateau level. These persons underwent computed tomography scanning and cisternography, revealing significant communicating hydrocephalus. After surgical shunt therapy, cognitive improvement was noted in 86%. Nineteen individuals were sent for rehabilitation following spine fracture or progressive quadriplegia; 17 were found to have persistent spinal instability requiring surgical stabilization by fusion. This was successful in all cases without complications. Two persons required decompressive spinal operations, resulting in neurological stabilization or improvement. Five patients developed pain, spasticity, ascending neurological deficit, or autonomic dysreflexia due to posttrau‐matic syrinx. These symptoms were stabilized or improved following syringosubarachnoid shunting. The authors submit that comprehensive neurosurgical reevaluation is desirable in patients received for rehabilitation. Periodic neurosurgical follow‐up is recommended. The neurosurgeon's role is not limited to the acute process. (Neurosurgery18:311‐315, 1986)

ISSN:0148-396X    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

&NA;Pituitary glands from neonatal donors were transplanted to the median eminence of hypophysectomized adult rats. Rats with transplants were then treated for 2 weeks with the immunosuppressive drug cyclosporine. For 5 weeks thereafter, blood was drawn at regular intervals for determination of serum thyroxine, prolactin, and luteinizing hormone. Cyclosporine‐treated recipients of grafts with minor histocompatibility differences had normal levels of thyroxine and prolactin, whereas untreated animals did not. In addition, the treated animals responded to oophorectomy with a marked elevation in serum luteinizing hormone. This evidence indicates that cyclosporine enables successful transplantation across a minor histocompatibility barrier. It also suggests that these grafts interact with the hypothalamus. Transplantation across a major histocompatibility barrier was unsuccessful even in the presence of cyclosporine. (Neurosurgery18:316‐320, 1986)

ISSN:0148-396X    

出版商:OVID    

年代:1986

数据来源: OVID