摘要:

THE SUPERIOR ORBITAL fissure (SOF) is a small (3 × 22 mm), but functionally very important, region. The microsurgical anatomy of the SOF was studied on five adult, formalin-fixed cadavers. The vascular structures of three of them were injected with latex. The SOF contains the third, fourth, and sixth nerves, the ophthalmic branch of the fifth nerve, and the superior orbital vein. It is divided by the two tendons of the lateral rectus muscle: the superior part contains the fourth nerve, the frontal and the lacrimal branches of the ophthalmic division of the fifth nerve, and the superior orbital vein; the inferior part contains the superior and inferior branches of the third, the nasociliary, and the sixth nerves. In regard to surgical access to lesions involving the SOF, the question is often raised as to whether the dissection should be started from the cranial or the orbital side. The following procedure is recommended: 1) frontotemporo-orbital craniotomy; 2) resection of the lesser wing of the sphenoid bone, of the anterior clinoid, and of the superolateral part of the orbital roof and opening of the dura along the Sylvian fissure, with an extension to the frontal lobe and another extension to the temporal lobe; 3) incision of the periorbita in its superolateral part and identification of the frontal nerve; and 4) dissection of the frontal nerve in an anteroposterior direction. The fourth nerve will be found medially and inferiorly to the frontal nerve. The third nerve will be found inferomedially to the frontal nerve in the SOF, and the sixth nerve will be found inferiorly to the inferior branch of the third nerve.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

THE RETROVIRUS-MEDIATED TRANSFER of the herpes simplex virus-thymidine kinase (HSV-tk) gene into tumor cells renders them sensitive to the cytocidal effect of the antiviral drug ganciclovir. This method has shown promising results as a treatment for experimental brain tumors. These experiments indicate that a major mechanism for the effectiveness of HSV-tk retroviral gene therapy may be the bystander tumoricidal effect. The bystander effect was hypothesized to explain tumor eradication, given that the efficacy of in vivo gene transfer to tumor cells was less than 100%. We demonstrate, in this report, that the bystander tumoricidal effect is a major contributor to the tumoricidal effect of ganciclovir in cell culture experiments using the mouse K1735 C19 cerebral melanoma line, thereby expanding the observation of the bystander phenomenon to a broader range of tumor types. The bystander effect was studied in vitro by coculturing wild-type C19 melanoma cells with HSV-tk-expressing C19 (C19-STK) cells. A maximal tumoricidal effect was seen when only 1 in 10 tumor cells expressed the HSV-tk gene. This suggests that in effect, 1 tumor cell with the HSV-tk gene, when given ganciclovir, will destroy 10 neighboring or bystander cells. The destruction of bystander cells does not appear to be mediated by a soluble factor(s) released into the media but, rather, requires close cell proximity or cell contact. In addition, HSV-tk-expressing C19 cells can exert an antitumoral effect not only on wild-type C19 cells but also on cells from a variety of different tumor cell lines, including a human glioblastoma multiforme cell line, indicating that the bystander effect is not a cell line-specific phenomenon. Finally, we observed that the bystander tumoricidal effect could be harnessed directly without using retrovirus-producing cells to increase survival in the mouse C19 brain tumor model. The potential implications of our findings in treating human brain tumors are discussed.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

THE RELATIONSHIP BETWEEN the severity of the posttraumatic functional deficit and findings on magnetic resonance imaging (MRI) was investigated in a rat model of experimental spinal cord trauma. Thirty Sprague-Dawley rats were subjected to an identical, moderate, contusion injury of the spinal cord. Control animals underwent laminectomy without cord injury. The severity of the functional deficit was assessed with the Combined Behavioral Score (CBS). Animals were killed at 3, 7, 14, 21, or 28 days after injury, and the fixed, excised spinal cords were studied with MRI at 1.9 T. The lesion length was measured on sagittal spin-echo MRI. The lesion length measured on MRI was highly correlated with the CBS functional score (r= 0.56,P= 0.002). There were significant correlations between lesion length as determined by MRI and by histological morphometry (r= 0.44,P= 0.02), between histological morphometric lesion length and CBS functional deficit (r= 0.76,P< 0.001), and between the area of residual white matter at the lesion epicenter, determined by histological techniques, and the severity of functional deficit (r= −0.59,P= 0.001). A qualitative estimate of the area of preserved white matter, derived from MRI, was significantly correlated with the severity of functional deficit (r= −0.56,P= 0.006). A multiple regression of MRI-determined lesion length and MRI estimate of residual white matter versus CBS explained more than 42% of the variability of the functional deficit among these animals subjected to the same weight drop injury. We conclude that MRI parameters are reliable predictors of the severity of neurological deficit in experimental spinal cord trauma.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

HYDROSYRINGOMYELIA WAS PRODUCED experimentally by the injection of kaolin into the cisterna magna of the rabbit, and the ultrastructural changes of the spinal cord surrounding the syrinx were investigated 2, 4, and 6 weeks after injection by transmission electron microscopy. The ependyma at the ventral part of the central canal was flat and stretched, whereas, in the dorsal part, it was split, and the syrinx extended through the dorsal median plane in most animals. Extracellular edema was found in the subependymal white matter and in and around the posterior median septum. Many nerve fibers surrounding the syrinx were in varying stages of axonal degeneration. Myelin sheaths were split, thinned, and completely lost in many nerve fibers. In some fibers, the axons were totally lost, leaving the myelin sheaths as empty tubes. Astrocytic processes containing a large number of glial filaments covered the nerve fibers adjacent to the syrinx and partially replaced the edematous area. The perivascular spaces were enlarged, especially near the syrinx and in the dorsal white matter. Oligodendrocytes remained undamaged, and the remyelination by oligodendrocytic processes was seen on some denuded axons. Sometimes, this further remyelination was abortive, especially where the edema was severe. The ultrastructural changes of the neural tissue and their sequences were identical, in most respects, to those of hydrocephalus and noncommunicating syringomyelia. The oligodendrocytic remyelination with ongoing demyelination found in this model has many similarities to those in experimental hydrocephalus.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

A LATERAL EXPOSURE of the cervicothoracic spine by an approach giving access to the anterolateral aspect of the vertebral bodies between C3-T10 is described. The approach of that region is obtained by the association of a cervicotomy and a standard thoracotomy with a costal flap situated at the place of the scapula. This approach was used for one patient with tumor invasion in the anterior part of the spinal canal on T1-T3; it allowed extensive resection of the three successive metastatic vertebral bodies and permitted stabilization of the spine.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

THE GLOBAL IMPROVEMENT of all parkinsonian symptoms after stereotactic pallidotomy has been demonstrated by Leksell. Recently, Laitinen, reevaluating this target in the neurosurgical treatment of Parkinson's disease, confirmed the real value of this approach, and emphasized the necessity of locating the lesion in the ventroposterolateral part of the pallidum internum. Because we know that high-frequency stimulation of the ventrolateral part of the thalamus has the same clinical effect on tremor as high-frequency coagulation, this technique has now been applied bilaterally in one session in three patients who have severe Parkinson's disease, with akinesia and levodopa-induced dyskinesias in the foreground. The very satisfactory clinical results, up to 12 months in the first case, confirm the observation of Laitinen, but with the difference that the approach discussed here is both nondestructive and reversible, and unwanted side effects are avoided.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

PRIMARY INTRAOSSEOUS ORBITAL hemangiomas are rare tumors. Only 25 cases have been reported in the literature. Very few of them have multiple orbital bone involvement. We report a case with extensive involvement of the orbital roof, the medial and lateral walls of the orbit, and the lesser and greater wings of the sphenoid, and describe a unilateral extradural frontotemporal approach to excise the tumor and decompress the right superior orbital fissure and both optic nerves. A brief clinical and radiological review of the literature is presented.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

A CASE OF cerebellopontine angle petrous bone osteoma manifesting as homolateral trigeminal neuralgia and causing a mild brain stem compression is presented. The literature concerning osteomas and particularly those affecting the temporal bone is reviewed. This is the second report of an osteoma located on the inner surface of the petrous bone and causing intracranial complications. Moreover, we discuss the intracranial tumors presenting with trigeminal neuralgia or atypical facial pain.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

LEVAMISOLE AND 5-FLUOROURACIL have now become the standard chemotherapeutic regimen for patients with Stage III colon carcinoma. A case of multifocal inflammatory leukoencephalopathy secondary to levamisole alone or combination of levamisole and 5-fluorouracil is reported. Magnetic resonance imaging with gadolinium demonstrated multifocal contrast-enhancing frontal, parietal, occipital, and periventricular white matter lesions. A stereotactic biopsy revealed reactive gliosis and macrophage infiltration, without evidence of metastatic tumor. Despite continuation of 5-fluorouracil, resolution of contrast-enhancing lesions on magnetic resonance imaging without further neurological sequelae occurred when levamisole was stopped. The patient died with evidence of systemic metastasis 6 months later. Autopsy examination of the brain revealed multifocal demyelinating lesions, with no evidence of metastatic tumor. Immunoperoxidase studies of demyelinated lesions demonstrated infiltrating macrophages strongly positive for Class II antigens, interleukin-6, and interleukin-1α. Surrounding astrocytes were positive for granulocyte macrophage colony-stimulating factor. Small numbers of perivascular T cells were present. This patient represents the first autopsy documented case of levamisole associated multifocal inflammatory leukoencephalopathy.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

A 55-YEAR-OLD WOMAN with a unique form of chronic hypertrophic pachymeningitis involving the posterior fossa and upper cervical spine is reported. Unlike other cases previously described, the clinical picture was dominated by signs of increased intracranial pressure, lower cranial nerve disorders, and a progressive cervical radiculomyelopathy. The diagnosis was made by means of a contrast-enhanced magnetic resonance imaging scan and confirmed by histological examination of the excised dura. Surgical treatment with removal of the hypertrophic dura provided temporary relief, although the natural history of the disease was not modified. Exhaustive bacteriological and histopathological studies failed to identify a specific cause for this diffuse hypertrophy of the cranial and cervical dura. The literature is reviewed, and other histologically documented cases are discussed.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID