1/59. Persistent trigeminal neuralgia after removal of contralateral posterior cranial fossa tumor. Report of two cases.BACKGROUND: Contralateral trigeminal neuralgia as a false localizing sign in patients with posterior cranial fossa tumors is rare. Persistent contralateral trigeminal neuralgia after removal of the posterior fossa expanding lesion with microsurgical exploration of the affected trigeminal nerve root has been described in only a few reports. Displacement of the brainstem and the trigeminal nerve root, arachnoid adhesions, and vascular compression of the nerve root entry zone have been reported as causes of persistent contralateral trigeminal neuralgia. methods: One patient developed transformation of the contralateral constant burning facial pain into trigeminal neuralgia after removal of a posterior fossa meningioma. A typical right-sided tic douloureux in our second patient did not disappear after removal of a left acoustic neurinoma. CT scan revealed brainstem displacement to the side of trigeminal neuralgia. Microsurgical exploration in both cases demonstrated the squeezed and distorted trigeminal nerve root and displaced brain stem with no vascular involvement. Both patients underwent partial trigeminal rhizotomy for pain control. RESULTS: Complete disappearance of the trigeminal neuralgia was evident in both cases with postoperative facial sensory loss. The postoperative course in the first case was uneventful; the second patient died from purulent meningoencephalitis. CONCLUSION: Persistent contralateral trigeminal neuralgia after removal of a posterior fossa tumor is caused by distortion of the fifth nerve root by the displaced brainstem. Partial trigeminal rhizotomy can be performed for alleviation of facial neuralgic pain in cases without neurovascular compression.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
2/59. Stereotactic radiosurgery for jugular foramen schwannomas.BACKGROUND: Jugular foramen schwannomas pose difficult management problems because of the surgical risk of lower cranial neuropathy. The indications and results of stereotactic radiosurgery are not well documented. methods: We reviewed our 10-year experience in the management of 17 patients who had jugular foramen schwannomas managed with the gamma knife. Thirteen patients previously had undergone surgery (range, 1-6 resections). Four patients had multiple cranial nerve deficits before microsurgical resection; 12 developed multiple lower cranial nerve palsies after resection. Four patients underwent radiosurgery based on imaging criteria alone. Conformal dose planning (tumor margin dose of 12-18 Gy) successfully encompassed the irregular tumor volumes in all patients. RESULTS: Follow-up varied from 6 to 74 months. Tumor size decreased in eight patients, remained stable in eight, and increased in one patient during the average follow-up interval of 3.5 years. Six patients improved and 10 others retained their preradiosurgery clinical status. One patient had an increase in tumor size and clinical deterioration 6 months after radiosurgery and underwent microsurgical resection. No patient developed new cranial nerve or other neurological deficits after radiosurgery. CONCLUSIONS: We believe that gamma knife radiosurgery is an effective alternative to microsurgical resection for patients who have small tumors and intact lower cranial nerve function. It is also effective for patients who have residual or recurrent tumors after microsurgical resection.- - - - - - - - - - ranking = 0.8keywords = nerve (Clic here for more details about this article) |
3/59. Preservation of olfaction in anterior skull base surgery.OBJECTIVES/HYPOTHESIS: In selected unilateral tumors and defects of the anterior skull base, the preservation of contralateral olfaction is achievable through a localized subcranial approach without compromising surgical objectives of resection or repair. STUDY DESIGN: Description of a functional adaptation of anterior skull base surgical techniques through a retrospective patient series. methods: Nine patients underwent anterior skull base surgery for unilateral cribriform plate disease including four malignant and two benign tumors, two encephaloceles, and one iatrogenic cribriform injury with cerebrospinal rhinorrhea. All nine patients consented to a localized subcranial approach to the anterior skull base to preserve the contralateral olfactory nerves. In four patients with benign disease a portion of the ipsilateral nerves was additionally conserved. Postoperative olfaction was assessed objectively with a commercially available smell test. Indications, technique, results, and complications are reported and discussed. RESULTS: All patients had eradication of disease with preservation of functional olfaction CONCLUSIONS: Conservation of olfaction is possible in selected cases of anterior skull base surgery when the lesion is unilaterally confined.- - - - - - - - - - ranking = 0.4keywords = nerve (Clic here for more details about this article) |
4/59. Complications of venous insufficiency after neurotologic-skull base surgery.OBJECTIVE: To characterize the incidence and complications resulting from venous insufficiency after neurotologic-skull base surgery. STUDY DESIGN: Retrospective case review of >3,500 cases. SETTING: Tertiary referral center, inpatient surgery. patients: Six patients: four with complications related to chronic venous insufficiency and two with complications related to acute venous insufficiency. INTERVENTION(S): Medical (steroids, acetazolamide, hyperventilation, mannitol) and surgical (lumboperitoneal shunt, optic nerve decompression, embolectomy) interventions were undertaken. MAIN OUTCOME MEASURE(S): Chronic venous insufficiency: nonobstructive hydrocephalus manifested by headache, disequilibrium, and papilledema with resultant visual loss. Acute venous insufficiency: acute nonobstructive hydrocephalus resulting in mental status abnormalities in the postoperative period. CONCLUSIONS: (1) incidence of 1.5 per 1,000 cases. (2) Acute and chronic forms with different pathogenesis. (3) Acute form presents postoperatively with change in consciousness and herniation, and may proceed to death. (4) Chronic form presents months or years postoperatively with headache, disequilibrium, and visual changes from papilledema. (5) Occurs almost solely in patients with preoperative abnormalities of the venous collecting system. (6) Causes mental status changes postoperatively.- - - - - - - - - - ranking = 0.2keywords = nerve (Clic here for more details about this article) |
5/59. Oral ulcerations as the first sign of a foramen magnum meningioma.We report the case of a patient with oral ulcerations that were likely traumatic in origin caused by biting of the tongue. physical examination showed only deviation, fasciculations, and hemiatrophy of the right side of the tongue. neurologic examination disclosed an isolated XII nerve palsy. A magnetic resonance image showed a lesion in the posterior fossa displacing the brain stem at a bulbar level. This was consistent with the diagnosis of a meningioma, later confirmed by the histopathologic study. It is very unusual that a meningioma produces a selective involvement of the XII nerve. early diagnosis of a foramen magnum meningioma is important, both to improve prognosis and to avoid neurologic sequelae.- - - - - - - - - - ranking = 0.4keywords = nerve (Clic here for more details about this article) |
6/59. Interstitial brachytherapy for skull base tumors.1. Irrespective of the histology, all tumors responded to 125I permanent BT. 2. There were no intra- or postprocedural complications, making this modality extremely safe. 3. There were no acute or late complications attributable to continuous LDR radiation with 125I permanent BT. 4. The dose distribution can be tailored to fit the tumor shape by seed placement at the desired location and by selecting the seed strength. 5. Unlike any other radiation therapy procedure, with SBT, the placement of the 125I seed or seeds is verifiable at each step of the procedure on the CT screen, making the treatment more accurate. 6. The procedure is performed under local anesthesia, and the patient is observed overnight at the most, making it safe and cost-effective. 7. Most skull base tumors are located close to the brain, cranial nerves, or blood vessels. Tolerance of these vital structures to high doses of radiation when given continuously at a LDR makes this treatment method safe.- - - - - - - - - - ranking = 0.2keywords = nerve (Clic here for more details about this article) |
7/59. An unusual case of primary lymphoma of the skull base extending from cerebellopontine angle to cavernous sinus and orbit. A case report.The authors describe a rare case of a primary central nervous system lymphoma of the cerebellopontine angle, extending into the right cavernous sinus and orbit. The patient presented with multiple right sided cranial nerve palsies and rapidly progressive proptosis and ophthalmoplegia of the right eye. Imaging revealed a cerebellopontine angle mass extending into cavernous sinus. Surgical decompression of the tumor was undertaken through a right sided retromastoid craniectomy. Histopathology revealed Non Hodgkin's lymphoma of diffuse large cell type. There was no evidence of systemic lymphoma. Primary lymphoma of cerebellopontine angle with direct extension into cavernous sinus and orbit is rare and to our knowledge this is the only case reported.- - - - - - - - - - ranking = 0.2keywords = nerve (Clic here for more details about this article) |
8/59. Linear accelerator based radiosurgery as a salvage treatment for skull base and intracranial invasion of recurrent nasopharyngeal carcinomas.Nasopharyngeal carcinoma is a common disease entity in taiwan. It can spread in the prestyloid, retrostyloid compartments, parapharyngeal space, and skull base, and induce paralysis of cranial nerves. We have treated more than 1,500 cases in the past 14 years. Since 1994, we have treated 11 cases of nasopharyngeal carcinomas with skull base invasion by linear accelerator-based stereotactic radiosurgery. There were six male and five female patients. The mean age was 48.4 years. Seven patients had symptoms of low cranial nerves. For these patients, conformal radiotherapy plus brachytherapy was used for the masses beyond the skull base. Stereotactic radiosurgery with a dose of 10 Gy to 19 Gy for one treatment was used for the masses invading the skull base. Eight patients died in follow-up periods from 5 months to 2 years 7 months. Approximately half of patients revealed good response of tumor to radiosurgery. Two patients demonstrated no response of tumors to radiosurgery. Stereotactic radiosurgery may be an adjuvant treatment for recurrent nasopharyngeal carcinomas with skull base and intracranial invasion.- - - - - - - - - - ranking = 0.4keywords = nerve (Clic here for more details about this article) |
9/59. A huge osteoblastoma with aneurysmal bone cyst in skull base.We reported a case of a huge osteoblastoma in the skull base of a young girl who had developed blindness in her right eye 1 year prior to examination. CT showed a large expansile bony lesion with eggshell margin over the skull base. MR imaging showed mixed solid and cystic parts with multiple fluid-fluid levels in the lesion. The optic chiasma and bilateral optic nerves were severely compressed by the tumor.- - - - - - - - - - ranking = 0.2keywords = nerve (Clic here for more details about this article) |
10/59. Renal cell carcinoma with skull base metastasis preceded by paraneoplastic signs in a chronic hemodialysis patient.A 59-year-old man who had received chronic hemodialysis developed left occipital pain and hypoglossal nerve palsy. He was diagnosed as having skull base metastasis from renal cell carcinoma related to acquired cystic kidney. Retrospective analysis revealed the patient had had elevated serum c-reactive protein and alkaline phosphatase levels before the symptoms appeared. radiotherapy to the skull base relieved the pain. Finally he died with generalized metastases. serum interleukin-6 levels measured during admission had been elevated, and interleukin-6 mRNA was detected in the autopsy specimen of renal cell carcinoma. interleukin-6 might be involved in the etiology of paraneoplastic signs.- - - - - - - - - - ranking = 0.2keywords = nerve (Clic here for more details about this article) |
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