摘要:

Benign cerebellar astrocytomas of childhood are potentially surgically curable lesions. Histologically, these neoplasms can be divided into pilocytic and diffuse astrocytomas. Whether there is a difference in the recurrence rate between these two tumor types after a surgical resection is not clear. In addition, the role of immediate postoperative imaging in predicting a recurrence has not been established. To answer these questions, we have reviewed the charts of 23 patients with benign cerebellar astrocytomas treated at Childrens Hospital of Los Angeles over a 10-year period (1977–1987). Of the 23 tumors, 15 were pilocytic and 8 were diffuse. All patients underwent an attempted gross total surgical removal of the tumor, and all patients had a postoperative computed tomographic (CT) scan with and without intravenously administered contrast material performed within 72 hours of the operation. Based on the postoperative CT scan, 12 patients had residual tumors. Seven of the subtotally resected tumors were pilocytic (7 of 15), and 5 were diffuse (5 of 8). Interestingly, the surgeon believed that a gross total resection had been obtained in 9 of these patients. There have been 4 recurrences in these 23 patients, with a mean follow-up of 4.9 years. All recurrences were in patients with subtotal resections. Of the 11 patients with a total resection of the tumor, 7 developed a small rim of enhancement on subsequent scans an average of 5 months after the operation. There have been no recurrences in these 11 patients. These results suggest that the surgeon's impression of the degree of resection is not accurate, that patients with gross total resections on immediate postoperative CT scans do well regardless of the histological findings, and that the appearance of a small rim of enhancement on subsequent CT scans does not herald the presence of a recurrent tumor.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Of 100 children with supratentorial gliomas (excluding gliomas of the anterior visual pathways) treated at the Children's Hospital of Pittsburgh from 1980 to 1990, 34 had malignant gliomas. Follow-up was adequate in 33 of these patients, and an antemortem diagnosis of dissemination of the malignant glioma via the cerebrospinal fluid (CSF) was made in 11. Of these 11, 8 were boys and 3 were girls; they ranged in age from 17 months to 16 years at the time of diagnosis of the primary glioma. The distribution of histological types was as follows: glioblastoma multiforme, 4; malignant oligodendroglioma, 3; anaplastic astrocytoma, 2; malignant mixed glioma, 1; and malignant ependymoma, 1. The interval between diagnosis and CSF dissemination ranged from 1 week to 59 months (median, 8 months). Survival after dissemination ranged from 3 weeks to 11 months (median, 4 months). Two patients were alive 5 and 3 months after diagnosis of dissemination, respectively. These 11 patients were compared with the other 22 patients who did not have CSF dissemination. The risk factors for dissemination suggested by our data were male sex, ventricular operative entry, multiple resections, and malignant oligodendroglioma. Because of the high incidence (33%) of CSF dissemination, postoperative evaluation of the craniospinal axis with gadolinium-enhanced magnetic resonance imaging should be performed on all children with supratentorial malignant gliomas. Moreover, since the mortality is extremely high once dissemination has occurred, craniospinal irradiation should be considered in children with one or more of the above risk factors, even before symptoms or definite radiological evidence of CSF dissemination emerge.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

In 31 children (age, 2–17 years) and 1 adult, individual dorsal root action potentials (DRAPs) from the S1-S3 roots were recorded intraoperatively after electrical stimulation of the dorsal penile or clitoral nerves, in preparation for surgery within the cauda equina. In most patients, pudendal afferent activity was present in S2 and S3 bilaterally; in some, the afferent activity was confined to a single root bilaterally, and in one, to a single root on one side. Dorsal root action potentials of small amplitude were recorded from S1 in 15 patients, although in no patient was S1 the primary carrier of these afferents. No lesion of the roots or rootlets carrying significant afferent activity was created during the rhizotomy, and no dysfunction in micturition resulted. We propose that the neurophysiological identification of roots and rootlets carrying afferent activity from the penile or clitoral nerves allows for rhizotomy of the S2 roots with the least possible risk of postoperative micturition and sexual dysfunction.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

This study investigated the differential effects of graded spinal cord injury on the rat extrapyramidal motor evoked potential (exp-MEP) and pyramidal motor evoked potential (pyr-MEP) and the prognostic value of these effects in predicting postinjury motor performance in the rat model. In 20 rats subjected to graded spinal injury (10–100 g-cm), there was a differential injury threshold for ablation of exp-MEP and pyr-MEP. All peaks of the pyr-MEP were extinguished in the animals subjected to impact forces of 50 g-cm and above (n = 12). In contrast, the exp-MEP was completely abolished in only two animals at injuries of 80 g-cm or above. A residual exp-MEP response persisted in the remaining 18 animals. Motor performance was monitored in 16 additional animals for up to 1 week after spinal injury. The pyr-MEP was abolished in 100% of the rats subjected to a 50-g-cm injury (n = 7), whereas the exp-MEP persisted up to the highest impact forces (80 g-cm). Hind leg paralysis was present in the five rats where the pyr-MEP was extinguished but with persistence of the exp-MEP. An 80% reduction in the amplitude of the pyr-MEP in four animals resulted in mild ataxia with motor improvement at the end of a week. An increase or a 70% loss in pyr-MEP peak amplitude resulted in no clinical motor deficits (n = 5). These findings demonstrate that the exp-MEP and pyr-MEP are differentially affected by spinal cord injury and that an alteration in the postinjury pyr-MEP is an accurate prognosticator of motor function. These findings have significant implications for the evaluation of potential therapeutic modalities in the rat spinal injury model.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The effects of some commonly used intravenous and inhalational anesthetic agents on the motor evoked responses to transcranial magnetic cortex stimulation were assessed in 17 subjects. Compound motor action potentials (CMAPs) of the abductor digiti minimi muscle were recorded. Baseline values (12 stimulations/subject) were established before anesthesia was induced with a single agent administered in steps up to a maximal dose (MaxDose). Cortical stimulation was performed and depth of anesthesia was assessed according to Guedel after each dose. A common feature was the marked intra- and interindividual variability of baseline values of CMAPs in those patients not premedicated, those premedicated, and the anesthetized patients. The average amplitude of CMAPs was related to the depth of anesthesia in a given subject, whereas onset latencies of CMAPs did not systematically change. CMAPs were markedly reduced or abolished after administration of potent sedative drugs such as midazolam (MaxDose, 0.4 mg/kg body weight), pentothal (MaxDose, 8 mg/kg), propofol (MaxDose, 2 mg/kg), and isoflurane (MaxDose, 1.9 and 3.7 vol %), as soon as patients reached Stage II and Stage III anesthesia. When fentanyl (MaxDose, 8 μg/kg) or nitrous oxide (MaxDose, 79%) was used, the subjects reached Stages I and II, but not Stage III. With these drugs, reliable recording of CMAPs was possible even with the maximal administered dose.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Two patients with esthesioneuroblastomas that disseminated in the central nervous system (CNS) and elsewhere are reported. The latest recurrences in the CNS were 19 years after the diagnosis in one patient and 9 years after the diagnosis in the other. Because the treatment of patients with such late recurrences is complicated by previous surgical procedures and radiation therapy, we review therapeutic options for these patients. The literature has not previously stressed the occurrence of late metastases, including those to the CNS, after prolonged disease-free intervals.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

A case of intraparenchymal schwannoma is presented. The neuroradiological findings of reported intraparenchymal schwannomas, including the case reported here, are discussed. The specific tumor characteristics are emphasized. This report appears to be the only documentation as a result of magnetic resonance imaging of this specific tumor.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Cavernous sinus hemangiomas represent 3% of all benign cavernous sinus tumors. They are dangerous tumors because of the risk of excessive bleeding, but they are easier to dissect from surrounding structures than meningiomas because of the presence of a pseudocapsule. Three cases where total excision was achieved with minimal blood loss, without stroke, and with preservation of cranial nerve function in 2 cases are reported, and 50 cases from the literature are reviewed. Hemangiomas can be distinguished preoperatively from over one-half of meningiomas by their marked hyperintensity on T2-weighted magnetic resonance imaging. They arise within the cavernous sinus and extend laterally by dissecting between the two layers of dura lining the floor of the middle fossa. Cranial nerves III, IV, and V remained stretched over the tumor surface within the overlying dura, whereas cranial nerve VI is found within the tumor and is the most difficult cranial nerve to preserve. Principles for successful and safe excision include preoperative assessment of the safety of temporary or permanent carotid artery occlusion, obtaining early proximal carotid artery control, carefully developing the plane between the dura and the tumor pseudocapsule, early devascularization of the tumor, and avoiding “piecemeal” tumor resection. A few cases demonstrated tumor shrinkage with radiation therapy which should be considered for patients with incomplete tumor excision or who are too ill to undergo surgery.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Spontaneous spinal epidural hematomas are well-recognized but rare entities. The standard treatment for these hematomas has been prompt surgical evacuation. The authors report a case of a 76-year-old man who precipitously became paraplegic secondary to a spontaneous spinal epidural hematoma and then experienced the complete resolution of his neurological deficit and the hematoma. We conclude that conservative (nonoperative) management of spontaneous spinal epidural hematomas may be appropriate in those instances in which there is early and sustained neurological recovery confirmed by radiological resolution of the lesion.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Pseudomeningocele formation is unusual after a lumbar discectomy. Four patients who developed a pseudomeningocele after lumbar disc surgery are reported. The pseudomeningocele was symptomatic in three patients. The diagnosis of a pseudomeningocele was made by computed tomography in conjunction with myelography in three patients and magnetic resonance imaging in the fourth. All patients underwent surgery for the pseudomeningocele with primary closure of the dural defect (the patient whose meningocele was asymptomatic also had an excision of an extruded disc), and postoperative results were gratifying.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID