Influence of different approaches to the cerebellopontine angle on the function of the intermediate nerve.

OBJECT: Surgery in the cerebellopontine angle (CPA) is a standard procedure at many centers. Outcome is focused mainly on preservation of hearing and facial function postoperatively. The nonmotor part of the facial nerve, the intermediate nerve, is nearly neglected nowadays. METHODS: A retrospective study was designed, including a questionnaire that was sent to 178 patients who had undergone surgery between 2000 and 2004. Data were obtained in 156 cases. The questionnaire was divided into five parts assessing the presence of increased tearing, reduced tearing, salivation disturbances, increased nasal secretions, and abnormalities in taste. Finally, a self-assessment of patient symptoms was analyzed. RESULTS: Postoperatively, 70 patients (45%) experienced crocodile tears, whereas 62 (40%) had dry eyes. Disturbances in taste were noted in six patients (4%) preoperatively and in 52 patients (33%) after surgery. Increased nasal secretion was noted in 68 patients (44%) postoperatively. An analysis of the correlation between the surgical approach used and disturbances in the intermediate nerve revealed a strong tendency to a higher rate of symptoms following the middle fossa approach (p = 0.071, chi-square test). CONCLUSIONS: Data in this study demonstrate the clinical importance of nonmotor defects associated with CPA tumor removal. More than 50% of the patients in this study reported postoperative crocodile tears, dry eyes, nasal secretions, and/or taste disturbances. These sequelae may affect both short- and long-term postoperative quality of life to the same extent as deafness or transient facial paresis. The risk of injury seems to be higher after the middle fossa approach.

Expression of vascular endothelial growth factor and basic fibroblast growth factor in sporadic vestibular schwannomas correlates to growth characteristics.

HYPOTHESIS: Expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) may have an impact on the growth characteristics of sporadic vestibular schwannomas (VSs). BACKGROUND: Vestibular schwannoma is a benign, slow-growing neoplasm that accounts for 6% of all intracranial tumors. The biological backgrounds for neoplastic growth and especially for the various growth patterns of VS remain largely unknown. Because several angiogenic and cytotrophic factors have been described to be involved in the growth of malignant tumors, we initiated this study to examine 2 major representatives of such growth factors in VS and their possible correlation to the growth characteristics of sporadic VSs. METHODS: Surgical specimens from 17 patients with sporadic VS were examined, and the expression of 2 major angiogenic and neurotrophic factors, bFGF and VEGF, was quantitatively analyzed at the mRNA and protein levels. The microvessel density (MVD) was defined by CD31 staining. RESULTS: All tumors showed expression of bFGF and VEGF at both the mRNA and protein levels. The mRNA expression and the protein expression of both growth factors correlated positive to tumor volume, to tumor growth index, and to MVD. CONCLUSION: The bFGF and VEGF mRNA expression and the bFGF and VEGF protein expression in sporadic VS correlates to the tumour volume, to the tumor growth index, and to the MVD. This might indicate an angiogenic and neurotrophic influence of these factors and a possible involvement in the growth of sporadic VS.

Dynamic posturography findings predict balance status in vestibular schwannoma patients.

OBJECTIVE: To test whether condition 5 score (C5S) and condition 6 score (C6S) of the sensory organization test of computerized dynamic platform posturography (CDPP) differ between vestibular schwannoma (VS) patients with and without vestibular symptoms. STUDY DESIGN: Retrospective review of prospectively collected data. SETTING: Tertiary academic referral center. PATIENTS: Two hundred and sixteen consecutive patients with a histological diagnosis of a VS (103 women; 113 men; age range, 18-78 years; median, 54 years) who had been preoperatively evaluated by CDPP. A hundred and twelve patients had a history of vertigo, dizziness, and/or imbalance, and 104 patients had neither present nor past vestibular symptoms at all. INTERVENTION: Diagnostic. Preoperative CDPP in VS patients with and without vestibular symptoms. MAIN OUTCOME MEASURES: Condition 5 score and C6S of the sensory organization test of CDPP of VS patients. To test whether C5S and C6S differ between VS patients with and without vestibular symptoms, the Wilcoxon-Mann-Whitney rank sum test was applied. RESULTS: Both C5S (p = 0.001) and C6S (p < 0.0005) were significantly lower in VS patients with vestibular symptoms than in VS patients without vestibular symptoms. CONCLUSION: There is a significant difference in the distribution of C5S and C6S between VS patients with and without vestibular symptoms. Thus, patients with symptoms tend to have lower C5S and C6S than patients without symptoms, although this trend is not sufficient for reliable discrimination for all patients.

Clinical and radiologic sequelae of the middle fossa approach to the internal auditory canal.

OBJECTIVE: This retrospective study aimed to characterize the postoperative nonneurotologic complications and radiologic findings after the middle fossa approach to the internal auditory canal (IAC). A grading system for computed tomography (CT) changes was developed. STUDY DESIGN: Sixty-two patients operated between 2000 and 2003 had CT scans of the head on the day after surgery. Their charts and films were reviewed. SETTING: R15 DK 54070-01A1: Tertiary referral center. RESULTS: Nine patients had complications, including seven with cerebrospinal fluid leakage, one with infection, and one with visual disturbances. Only three of these patients had CT changes. Alternatively, 14 patients had CT changes according to our grading system for edema, pneumatocephalus, and hematoma. Three of these patients had complications. The overall complication rate was low (15%), and there were no cases of serious damage to the temporal lobe. CONCLUSION: The middle fossa approach provides safe access to the IAC. With the use of flexible retractors, serious damage to the temporal lobe can be avoided. The CT scan on the first day after surgery is useful for detecting dangerous hematomas but should be correlated to the patient's condition because of non-specific radiologic changes and the potential for complications to be present even in the absence of CT findings.