1/978. Pediatric eighth cranial nerve schwannoma without evidence of neurofibromatosis. Schwannomas of the eighth cranial nerve are rare in children. We report a 4 10/12 - year-old girl with no evidence of neurofibromatosis who presented with facial droop. Radiographic studies revealed a large cerebellopontine angle tumor. At surgery, the tumor was attached to the eighth cranial nerve and histologically was a schwannoma. This is the youngest reported case of unilateral eighth cranial nerve schwannoma in a patient without the stigmata of neurofibromatosis. ( info) |
2/978. Schwannoma in patients with isolated unilateral trochlear nerve palsy. PURPOSE: To describe the clinical features of patients with isolated unilateral trochlear nerve palsy secondary to imaging-defined schwannoma of the trochlear nerve. methods: A chart review of all patients seen at the Neuro-ophthalmology Unit at Emory University since 1989. Of 221 patients with trochlear nerve palsy, six had a lesion consistent with a trochlear nerve schwannoma. RESULTS: The six patients had isolated unilateral trochlear nerve palsy. Duration of diplopia before diagnosis averaged 6 months. magnetic resonance imaging demonstrated circumscribed, enhancing lesions along the cisternal course of the trochlear nerve, all measuring less than 5 mm in greatest dimension. Five of the patients were seen in follow-up, over periods ranging from 11 to 26 months from initial presentation (mean, 15.6 months; standard deviation, 6.0 months). All of these patients remained stable except one, who was slightly worse at 15 months by clinical measurements and magnetic resonance imaging. None of these patients have developed additional symptoms or signs of cranial nerve or central nervous system involvement. CONCLUSIONS: The differential diagnosis of an isolated unilateral fourth cranial nerve palsy should include an intrinsic neoplasm of the trochlear nerve. magnetic resonance imaging is useful, both for diagnosis and follow-up. These patients can remain stable and may not require neurosurgical intervention. ( info) |
3/978. Cavernous angioma of the VIIIth cranial nerve. A case report. We report a case of a 24-year-old woman affected by a cavernous angioma of the right VIIIth cranial nerve associated with a venous angioma. The malformation was diagnosed by MRI, performed in relation to an acute onset of right anacusia. The case report is indicative that, even if unusual, an acute onset of an cerebellopontine angle syndrome can be subsequent to a bleeding cavernous angioma. This occurrence must be kept in mind in the differential diagnosis of the cerebellopontine angle tumors. ( info) |
4/978. Kadish stage C olfactory neuroblastoma successfully treated by chemoradiotherapy: report of two cases. Olfactory neuroblastoma is an uncommon tumor. It is usually diagnosed at advanced stages. Most of the patients have an indolent clinical course with slow progression, late recurrence and relative infrequency of distant metastasis. Because of the rarity and lack of a randomized clinical trial of patients with olfactory neuroblastoma, there is no standard treatment for the disease. The survival period has increased as treatments have been improved since 1980. Conventional treatments mainly consist of surgery and/or radiotherapy. Chemotherapy was only administered to a few patients; however, it achieved good response. More clinical experience is needed to improve the treatment strategy in order to reduce the possibility of disease recurrence, and also for rescue therapy. We present 2 patients with Kadish C tumors treated using chemotherapy followed by radiotherapy. Both patients demonstrated rapid and excellent response to induction chemotherapy, and have been free of disease for more than 5 years and 2 years after treatment, respectively. ( info) |
5/978. Case report and discussion of hearing preservation after translabyrinthine excision of small acoustic tumors. OBJECTIVE: Since 1991, three separate reports have shown how hearing may be salvaged after translabyrinthine excision of small acoustic tumors. The authors submit yet another report of a complete translabyrinthine excision of a 1.4-cm intracanalicular acoustic tumor with modest hearing preservation. An attempt is made to retrace the steps of the operation and recognize and discuss what particular events may have safeguarded the viability of the cochlea. With the availability of cochlear implantation, there should be added incentive to preserve the cochlear neurones if hair cells cannot be saved. STUDY DESIGN: The study design was a retrospective case review. SETTING: The study was conducted at a primary care hospital. INTERVENTION: Therapeutic and rehabilitative measures were performed. MAIN OUTCOME MEASURES: Hearing preservation was measured. CASE REPORT: A 55-year-old woman presented with a left-sided hearing loss and a 1.4-cm left acoustic tumor completely filling the internal auditory canal (speech reception threshold [SRT] 30 dB, discrimination [Pb] 28%). A successful translabyrinthine excision of the tumor was performed in November 1995. A 1-year postoperative audiogram showed a mixed hearing loss in the left ear with SRT 85 dB and Pb 0%. Average pure-tone threshold for 500 Hz, 1 kHz, and 3 kHz was 50 dB and aided SRT 40 dB with Pb 64%. Postoperative magnetic resonance imaging confirmed complete excision of the tumor. CONCLUSION: An exceptional case of hearing preservation after translabyrinthine excision of a small acoustic tumor illustrates how it may be possible to preserve cochlear hair cells and neurones simultaneously in certain selected cases. A review of the surgical events shows the value of sealing the cochlear duct with bone wax, selectively removing the vestibular nerves with the tumor by sharp dissection, and safeguarding the meatal segment of the anterior inferior cerebellar artery by a limited dural incision. ( info) |
6/978. Facial neuromas in children: delayed or immediate surgery? OBJECTIVE: The objective of this study was to investigate the clinical characteristics and outcome of facial nerve neuromas in children. To date, no specific study has focused on children, and the management of these tumors is not codified. DESIGN AND SETTINGS: A review of case series treated in a tertiary care center of pediatric otolaryngology. SUBJECTS: The treatment and outcomes for 7 children (4 infants and 3 adolescents) were analyzed. RESULTS: Six patients underwent complete removal of tumor and immediate restoration of the nerve continuity. The grade of facial palsy improved in 4 of the 6 children, but did not get better than grade 3 (House classification). The remaining patient was managed conservatively and remained stable clinically and radiologically after 9 years follow-up. CONCLUSIONS: These findings support the reasonable strategy of combining conservative assessment of these slow-growing tumors with regular clinical and radiologic evaluations and radical surgery using various procedures. The choice depends on the age of the child, the extent and growth rate of the tumor, the grade of facial palsy, and the hearing function. ( info) |
7/978. Surgical management of lesions affecting the anterior optic pathways. Although benign neoplasms are the most common lesions of the anterior visual pathways that lend themselves to a combined neurosurgical and ophthalmic surgical treatment, malignant neoplasms, infections (especially fungal), and vascular lesions are also sometimes treated via a combined approach. Recent advances in the field of skull base surgery have made it possible to treat complicated lesions in precarious locations with increasing margins of safety and decreasing morbidity. The role of the neurosurgeon in managing selected patients with lesions of the anterior a visual pathway should not be underestimated. ( info) |
8/978. A skull base extradural hypoglossal neurilemmoma resected via an extended posterolateral approach. The case of a 43-year-old man with a right skull base hypoglossal neurilemmoma excised via the extended posterolateral approach is presented. There is only one previous case of hypoglossal neurilemmoma in the literature. The surgical technique described is a new approach to the posterior skull base involving a suboccipital craniectomy, mastoidectomy and the removal of the lateral process of the atlas. It provides an inferior approach to the jugular foramen and hypoglossal canal that allows the lower cranial nerves to be identified as they exit from their skull base foramina. In the discussion we compare this technique to other surgical approaches previously described for access to the region of the jugular foramen. ( info) |
9/978. Primary lymphoma of Meckel's cave mimicking trigeminal schwannoma: case report. OBJECTIVE AND IMPORTANCE: We report the first case of primary lymphoma of Meckel's cave. The ability of a lymphoma to mimic a trigeminal schwannoma, both clinically and radiographically, resulted in misdiagnosis and flawed surgical strategy. We discuss the characteristics of a Meckel's cave lymphoma on magnetic resonance images, the predisposing medical conditions that should cause the neurosurgeon to add lymphoma to the normal differential diagnosis, and appropriate management strategies. CLINICAL PRESENTATION: A 40-year-old African-American woman presented with a 5-month history of progressive facial numbness and pain in all three divisions of the left trigeminal nerve. magnetic resonance imaging revealed a mass in the left side of Meckel's cave, with extension into the lateral compartment of the cavernous sinus, without encasement of the internal carotid artery, through the foramen rotundum into the posterior aspect of the maxillary sinus, and through the foramen ovale into the pterygopalatine fossa. The diagnosis, based on clinical history and radiographic imaging, was schwannoma of Meckel's cave. The patient had a history of systemic lupus erythematosus that had been treated with intermittent steroid therapy. INTERVENTION: The surgical approach selected was a frontotemporal craniotomy with orbitozygomatic osteotomy and anterior petrosectomy. The lesion was totally excised, although the gross intraoperative appearance of the lesion was inconsistent with the preoperative diagnosis, and the pathological examination was unable to establish a histological diagnosis on the basis of frozen sections. Histological diagnosis was confirmed on permanent section after surgery as B-cell lymphoma. Evaluation for other primary sites produced negative results. The patient was then treated with cyclophosphamide (Cytotoxan; Bristol-Myers Oncology, Princeton, NJ), doxorubicin (Adriamycin; Pharmacia & Upjohn, Kalamazoo, MI), vincristine, and prednisone chemotherapy every 3 weeks for six cycles and then by radiation therapy to the affected area. CONCLUSION: The diagnosis of lymphoma should be considered for lesions affecting Meckel's cave in high-risk immunocompromised patients. The presence of an apparent dural tail in an otherwise typical schwannoma is the distinguishing characteristic of a lymphoma. The absence of hyperostosis helps differentiate it from a meningioma. At this point, the preferred surgical strategy is biopsy for diagnosis and then radiotherapy and chemotherapy rather than major cranial base surgery for total resection. ( info) |
10/978. Spontaneous remission of chiasmatic/hypothalamic masses in neurofibromatosis type 1: report of two cases. We report two children with neurofibromatosis type 1 showing enhancing masses on MRI suggesting neoplasms in the chiasm and hypothalamic region. In both patients no visual or endocrinal dysfunction was present. On serial MRI spontaneous partial remission was found, implying that a cautious approach to therapeutic management of similar cases should be taken. ( info) |