Cases Of Vestibular Schwannoma Research Articles

Hearing preservation with the retrosigmoid approach for vestibular schwannoma: myth or reality?

Objective The purpose of this study is to present our experience with the retrosigmoid approach for vestibular schwannoma resection, emphasizing our hearing results, discussing selection and reporting results criteria. Study design and setting The notes of 65 consecutive cases of vestibular schwannoma undergoing the retrosigmoid approach were reviewed. Hearing data were reported according to the recommendations of the American Academy of Otolaryngology–Head and Neck Surgery (AAO-HNS). In addition, the terms normal, serviceable, useful, and measurable hearing were considered. Results Tumor size ranged from 8 to 50 mm (mean, 24.1 mm). Of the 29 patients with preoperative serviceable hearing (AAO-HNS classes A and B), 5 patients (17%) had postoperative serviceable hearing, and 6 patients (20%) had postoperative useful hearing (AAO-HNS classes A, B, and C). Conclusion The retrosigmoid approach is a reliable surgical procedure for most vestibular schwannoma tumors. However, hearing preservation results show wide differences depending on selection and reporting results criteria. Hearing preservation, although possible, may not be the main reason to choose this approach.

Hearing preservation with the retrosigmoid approach for vestibular schwannoma: myth or reality?

The purpose of this study is to present our experience with the retrosigmoid approach for vestibular schwannoma resection, emphasizing our hearing results, discussing selection and reporting results criteria.Study design and setting The notes of 65 consecutive cases of vestibular schwannoma undergoing the retrosigmoid approach were reviewed. Hearing data were reported according to the recommendations of the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS). In addition, the terms normal, serviceable, useful, and measurable hearing were considered. Tumor size ranged from 8 to 50 mm (mean, 24.1 mm). Of the 29 patients with preoperative serviceable hearing (AAO-HNS classes A and B), 5 patients (17%) had postoperative serviceable hearing, and 6 patients (20%) had postoperative useful hearing (AAO-HNS classes A, B, and C). The retrosigmoid approach is a reliable surgical procedure for most vestibular schwannoma tumors. However, hearing preservation results show wide differences depending on selection and reporting results criteria. Hearing preservation, although possible, may not be the main reason to choose this approach.

Outcome analysis of 40 cases of vestibular schwannoma: A comparison of sitting and Park bench surgical position

The present study retrospectively reviews our experience in 40 cases of vestibular schwannoma, operated between the years 1995 and 2002. All the patients underwent tumour resection either in sitting or in the Park bench position via the suboccipital retromastoid route. The position of the patient was selected arbitrarily. Precordial Doppler echocardiography was used to monitor air embolism. Operative results, including the size of the tumour, completeness of resection, anatomical and functional preservation of the facial nerve, operative complications and mortality were analysed and compared in these two operative positions. There was no statistically significant difference in terms of surgical results between these two groups.

The role of conservative management of vestibular schwannomas.

Although microsurgery is generally regarded as the conventional treatment of choice for most vestibular schwannomas, there remains a group of patients in whom a conservative management approach may be a desirable alternative. The aim of this study was to determine the natural history and outcome following the conservative management of 72 patients with unilateral vestibular schwannomas. The reasons for conservative management included poor general health, age, patient preference, small tumour size, minimal or no symptoms, and tumour in the only/better hearing ear. The mean duration of follow-up was 39.8 months (range 12-194 months). All patients underwent serial magnetic resonance imaging (MRI) for assessment of tumour growth. Patients were deemed to have failed conservative management if there was evidence of continuous or rapid radiological tumour growth and/or increasing symptoms or signs. The mean tumour growth rate, according to the 1995 guidelines of the American Academy of Otolaryngology/Head and Neck Surgery, was 1.16 mm/year (range: 0.75 9.65 mm/year). Approximately 83% of tumours grew at < 2 mm/year. Significant tumour growth was seen in 36.4%, no or insignificant growth in 50%, and negative growth in 13.6% of tumours. The growth rate of CPA tumours (1.4 mm/year) was significantly greater than that of IAC tumours (0.2 mm/year) (P = 0.001). Failure of conservative management, in which active treatment was required, occurred in 15.3%. The outcome of these patients appeared to be as favourable to a comparable group who underwent primary treatment, without a period of conservative management. The mean growth rate of tumours in patients who failed conservative management (4.2 mm/year) was significantly greater than that in patients who did not fail (0.5 mm/year) (P < 0.01). No factors predictive of tumour growth or failure of conservative management were identified. Deterioration of mean pure tone average (0.5, 1, 2, 3 kHz) and speech discrimination scores occurred regardless of whether radiological tumour growth was demonstrated or not. This study suggests that in a select number of cases of vestibular schwannoma, a conservative management approach may be appropriate. Regular follow-up with serial MRI is mandatory. Deterioration of auditory function occurs even in the absence of tumour growth.

Clinical observations on coexistence of sudden hearing loss and vestibular schwannoma.

It has long been recognized that sudden hearing loss (SHL) may be a harbinger of vestibular schwannoma (VS). Among 192 VS patients who underwent operation in the Gruppo Otologico, Piacenza, Italy, from April 1987 to October 1995, the charts of 14 (7.3%) cases with a history of SHL were examined. SHL was the first symptom in 8 (4.2%) patients. Eight (57.1%) of 14 VS cases with SHL anamnesis had reported recovery of their previous hearing either totally or partially before establishment of tumor diagnosis. Five (35.7%) cases had recurrent bouts of SHL. SHL was observed less frequently in cases with large tumors (>3 cm). However, the frequency of SHL in patients with small tumors did not differ from that of medium-sized tumors. Awareness about coexistence of SHL and VS, as well as concomitant use of auditory brain stem response and magnetic resonance imaging, is crucial to rule out the diagnosis of VS in a patient with SHL.

Clinical observations on coexistence of sudden hearing loss and vestibular schwannoma

It has long been recognized that sudden hearing loss (SHL) may be a harbinger of vestibular schwannoma (VS). Among 192 VS patients who underwent operation in the Gruppo Otologico, Piacenza, Italy, from April 1987 to October 1995, the charts of 14 (7.3%) cases with a history of SHL were examined. SHL was the first symptom in 8 (4.2%) patients. Eight (57.1%) of 14 VS cases with SHL anamnesis had reported recovery of their previous hearing either totally or partially before establishment of tumor diagnosis. Five (35.7%) cases had recurrent bouts of SHL. SHL was observed less frequently in cases with large tumors (>3 cm). However, the frequency of SHL in patients with small tumors did not differ from that of medium-sized tumors. Awareness about coexistence of SHL and VS, as well as concomitant use of auditory brain stem response and magnetic resonance imaging, is crucial to rule out the diagnosis of VS in a patient with SHL. (Otolaryngol Head Neck Surg 1997;117:580-2.)

Melanocytes in the Dark Cell Area of Human Vestibular Organs

By using surgical materials obtained from 7 cases of vestibular schwannoma, the ultrastructure of melanocytes in the dark cell area of human vestibular organs was examined by light microscopy and electron microscopy. Paraffin sections were stained with hematoxylin and eosin. Glutaraldehyde-fixed specimens were observed by electron microscopy. Melanocytes were found in the subepithelial layer of the dark cell area. Melanocytes had round or spindle-shaped nuclei and clear cytoplasm with brown pigment granules which were thought to be melanin granules. Besides melanocytes, there were fibroblasts and small blood vessels. By electron microscopy we found melanocytes with round shaped melanosomes in various stages of pigmentation, well-developed Golgi apparatus and endoplasmic reticulum in the cytoplasm, and many cytoplasmic processes. There were pinocytotic vesicles just under the limiting membrane of the melanocytes, and intermediate filaments were abundant in the cytoplasm. On the other hand long-spacing collagen was found in the connective tissue area around melanocytes.

Positive Hennebert's Sign in Meniere's Disease

A positive Hennebert's sign was found in 24 of 81 (30%) of ears with Meniere's disease and in none of 22 cases of vestibular schwannoma or 100 normal controls. Negative pressure applied to the external auditory canal was the required stimulus in 14 of 24 (58%) ears. The character of induced eye motion was variable, although horizontal nystagmus was found in 22 of 24 (92%) ears. A positive Hennebert's sign is seen in a variety of labyrinthine lesions and gives corroborative evidence for a cochlear site of hearing impairment with hydrops and vestibulofibrosis are the underlying pathophysiologic condition.