1/81. A new approach to an old problem.A patient with progressive visual loss was found to have an optic nerve sheath meningioma. The patient was treated with stereotactic radiotherapy, a computer-guided stereotactic technique that minimizes the risk of radiation-induced optic neuropathy. Six months after treatment, the patient was doing well and showed no signs of radiation-induced optic neuropathy.- - - - - - - - - - ranking = 1keywords = sheath (Clic here for more details about this article) |
2/81. Treatment of optic nerve sheath meningioma with three-dimensional conformal radiation.PURPOSE: To report a patient recovering vision after three-dimensional conformal radiotherapy for optic nerve sheath meningioma. methods: radiotherapy was delivered by a three-dimensional conformal technique in 28-180-cGy fractions. RESULTS: visual acuity improved from 20/200 to 20/30, and the visual field defect resolved. CONCLUSION: Visual loss from optic nerve sheath meningioma can be reversed by three-dimensional conformal radiotherapy.- - - - - - - - - - ranking = 6keywords = sheath (Clic here for more details about this article) |
3/81. Orbital color Doppler imaging of optic nerve tumors.OBJECTIVE: To report changes in retinal arterial and venous blood flow pattern in two patients with tumors involving the entire optic nerve. methods: Retrospective review of one patient with clinical and neuroimaging characteristics typical of bilateral optic nerve gliomas and one patient with a probable meningioma of the left optic nerve sheath. RESULTS: The optic nerve glioma patient had reduced peak systolic velocity of central retinal arteries bilaterally, while the patient with an optic nerve sheath meningioma had relatively low central retinal artery flow velocity and intermittent blood flow in the central retinal vein on the affected side. CONCLUSIONS: Reduced retinal arterial flow velocities in the setting of optic nerve gliomas may correlate with the presence of optic nerve disease. Phasic blood flow in the central retinal vein with optic nerve sheath meningioma may be the reason that some patients with this tumor develop retinal choroidal venous anastomoses.- - - - - - - - - - ranking = 3keywords = sheath (Clic here for more details about this article) |
4/81. Disk edema and cranial MRI optic nerve enhancement: how long is too long?A 43-year-old woman presented with painful visual loss and optic disk edema in the right eye (OD) diagnosed as optic neuritis. Initial non-gadolinium-enhanced fat suppressed cranial magnetic resonance imaging (MRI) was normal. Three months later, the disk edema persisted and a gadolinium-enhanced MRI scan of the brain and orbits with fat suppression showed enhancement of the optic nerve OD, most consistent with an optic nerve sheath meningioma. The diagnostic difference between optic neuritis and optic nerve sheath meningioma is discussed.- - - - - - - - - - ranking = 2keywords = sheath (Clic here for more details about this article) |
5/81. Caught by a masquerade: sclerosing orbital inflammation.Idiopathic sclerosing inflammation of the orbit is a distinct form of orbital inflammatory disease characterized by slow and relentless involvement of orbital structures. It is this insidious and relentless course that makes distinction from neoplastic lesions clinically difficult. We report the case of a patient with a several-week history of headache and decreased vision that was originally thought to represent an optic nerve sheath meningioma, based on clinical and radiographic evaluation. Subsequent histopathology from an optic nerve biopsy, however, was more consistent with optic nerve glioma. Eventually, pathologic examination of whole sections through the optic nerve was required to establish and confirm the actual diagnosis of sclerosing orbital inflammation.- - - - - - - - - - ranking = 1keywords = sheath (Clic here for more details about this article) |
6/81. Dumbbell-shaped meningioma with cystic degeneration in the thoracic spine: a case report.STUDY DESIGN: A case report of dumbbell-shaped meningioma in the thoracic spine with cystic degeneration for which a combined posterior microscopic and anterior thoracoscopic approach was used is described. OBJECTIVES: To report a rare case of dumbbell-shaped meningioma, and to describe a thoracoscopic surgical approach for paravertebral tumor. SUMMARY OF BACKGROUND DATA: Dumbbell-shaped tumors arising from nerve root sheaths are very common. However, a dumbbell-shaped meningioma is relatively rare, and reports on thoracoscopic resection of dumbbell and paravertebral tumors are still very few in number. methods: The dumbbell meningioma was managed surgically. Because of the paravertebral tumor's intrathoracic expansion, a combined posterior and anterior approach was used. With the posterior approach, microscopic resection using hemilaminotomy was performed, whereas with the anterior approach, the thoracoscopic approach was used instead of thoracotomy. RESULTS: Complete resection of the tumor was performed successfully. The patient regained his functional ability to walk soon after surgery because of less pain than with thoracotomy. CONCLUSIONS: With combined microscopic and thoracoscopic surgery, dumbbell-shaped meningioma could be completely resected. The thoracoscopic approach for the removal of a paravertebral tumor can be a good alternative to thoracotomy.- - - - - - - - - - ranking = 1keywords = sheath (Clic here for more details about this article) |
7/81. Optic nerve sheath meningiomas: visual improvement after stereotactic radiotherapy.OBJECTIVE: The management of primary optic nerve sheath meningioma (ONSM) is controversial. Surgery often results in postoperative blindness in the affected eye and thus has been abandoned as a treatment option for most patients. When these tumors are left untreated, however, progressive visual impairment ensues, which also leads to blindness. Recently, radiation therapy has gained wider acceptance in the treatment of these lesions. Experience with stereotactic radiotherapy (SRT) in the treatment of ONSMs is limited because of the rare incidence of this tumor. We present a series of patients with ONSM who were treated with SRT. methods: Five patients (three women, two men), ranging in age from 40 to 73 years, presented with progressive visual loss with decreased visual field, visual acuity, and color vision affecting six eyes (one patient had tumor involving both optic nerves). One patient also presented with proptosis and diplopia. Five eyes had functional residual vision (range, 20/20 to 20/40), and one eye was completely blind. All five patients were diagnosed clinically and radiographically to have an ONSM. Three were intraorbital, one was intracanalicular as well as intraorbital, and one was a left ONSM extending through the optic foramen into the intracranial space and involving the right optic nerve. The five functional eyes were treated with SRT by use of 1.8-Gy fractions to a cumulative dose of 45 to 54 Gy. RESULTS: Follow-up ranged from 1 to 7 years, and serial magnetic resonance imaging revealed no changes in the size of the tumor in all five patients. Four patients experienced dramatic improvement in visual acuity, visual field, and color vision within 3 months after SRT. One patient remained stable without evidence of visual deterioration or disease progression. None had radiation-induced optic neuropathy. CONCLUSION: SRT may be a viable option for treatment of primary ONSM in patients with documented progressive visual deterioration, and it may be effective in improving or stabilizing remaining functional vision.- - - - - - - - - - ranking = 5keywords = sheath (Clic here for more details about this article) |
8/81. Fractionated stereotactic radiotherapy for the treatment of optic nerve sheath meningiomas: preliminary observations of 33 optic nerves in 30 patients with historical comparison to observation with or without prior surgery.OBJECTIVE: We investigated the safety and efficacy of stereotactic radiotherapy as an alternative therapy to surgical resection for optic nerve sheath meningiomas (ONSMs). methods: Thirty patients and 33 optic nerves with ONSMs were treated with conventional fractionated stereotactic radiotherapy treatment (CF-SRT) between July 1996 and May 2001 with the use of a 6-MeV LINAC designed for and dedicated to radiosurgery. The LINAC technique involved daily CF-SRT involving a relocatable frame, an average of three isocenters, and high-radiation dose conformality established by noncoplanar arc beam shaping and differential beam weighting. The patients who were treated with CF-SRT were followed clinically with serial visual fields and radiographically with both magnetic resonance imaging and functional (111)In-octreotide single-photon emission computed tomography. The results of treatment were compared with a historical control group of ONSM patients who were either observed or treated surgically and then observed. RESULTS: Our study population comprised 18 women and 12 men with a median age of 44 years (age range, 20-76 yr). The median isosurface radiation dose was 51 Gy (dose range, 50-54.0 Gy), and the median clinical follow-up time was 89 weeks (range, 9-284 wk). Of 22 optic nerves with vision before CF-SRT, 20 nerves (92%) demonstrated preserved vision, and 42% manifested improvement in visual acuity and/or visual field at follow-up. Comparison of our patients with a historical control group revealed preserved vision in only 16% of patients in a comparable period of observation, along with a 150% greater probability of visual improvement. Four patients (13%) had posttreatment morbidities, including visual loss (two patients), optic neuritis (one patient), and transient orbital pain (one patient). On magnetic resonance imaging studies, there was no evidence of tumor progression or recurrence in all patients, including tumor volume reductions noted in four patients. All six patients monitored with (111)In-octreotide scintigraphy demonstrated significant decreases in tumor activity after CF-SRT. CONCLUSION: To date, this article describes the largest reported series of ONSMs. Although longer follow-up is necessary, we think that CF-SRT represents a safe alternative to surgery and offers a higher likelihood of preserved or improved vision in patients with ONSM. Our analysis suggests that CF-SRT is also preferable to observation. Functional (111)In-octreotide single-photon emission computed tomographic scintigraphy provides a useful technique for the assessment of tumor control that complements serial posttreatment magnetic resonance imaging in patients with ONSMs.- - - - - - - - - - ranking = 5keywords = sheath (Clic here for more details about this article) |
9/81. Bilateral optic nerve sheath meningiomas in a patient with neurofibromatosis type 2.A 34-year-old woman who presented with hearing loss and tinnitus was found to have reduced vision bilaterally. Computed tomography scan revealed bilateral acoustic neuromas and bilateral optic nerve sheath meningiomas. The presence of bilateral acoustic neuromas fulfils the criteria for the diagnosis of central neurofibromatosis (neurofibromatosis type 2). Although this is the first report of bilateral optic nerve sheath meningioma in neurofibromatosis type 2, meningiomas are commoner in this dominantly inherited disorder, than in its absence and both forms of central nervous system tumour may be caused by loss of tumour suppressor genes on chromosome 22.- - - - - - - - - - ranking = 6keywords = sheath (Clic here for more details about this article) |
10/81. Dura and cranial base reconstruction by external oblique fascia and rectus abdominis muscle flap.The rectus abdominis muscle flap, combined with the external oblique fascia, were utilized in cranial-base reconstruction. In a wide defect caused by resection of a giant meningioma, the dura was reconstructed with the external oblique fascia and anterior sheath, and the cranial-base defect was reconstructed with the rectus abdominis muscle flap.- - - - - - - - - - ranking = 1keywords = sheath (Clic here for more details about this article) |
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