Current Abstracts

D.A. Moffat, S.E.M. Jones, S. Mahendran, R. Humphriss, D.M. Baguley. Referral patterns in vestibular schwannomas-10 years on. Clin Otolaryngol 2005; 29: 515-517

Diagnostic imaging techniques, symptom awareness and education of local sources of referral in vestibular schwannomas, including general practitioners, have all improved in the last 10 years. The referral patterns in vestibular schwannomas in Cambridgeshire in the period 1981-1993 has been reported. A direct comparison was made with regard to referral patterns seen in the last 10 years paying particular emphasis to source of referral, diagnosis at referral and symptoms/size at presentation. The incidence of vestibular schwannomas in the region is compared and discussed. Patients' managed by the ‘watch and wait’ policy were particularly scrutinized, as they were not discussed previously. Retrospective analysis of computerized database was used. We have demonstrated an increase in the proportion of referrals with known vestibular schwannoma to 90% of all referrals. No significant change in length of history prior to referral, source of referral or principal presenting symptom were found. An overall decrease in tumour size was found but an increase in the percentage with larger tumours (>4.5 cm). We attribute the significant findings to an increase in availability of magnetic resonance (MR) scanners in the country during the past 10 years. It appears that some tumours would still present with no symptoms until late and therefore will elude identification until large in spite of a low threshold for MR scanning.

D. Sandooram, E.A. Grunfeld, C. Mckinney, M.J. Gleeson. Quality of life following microsurgery, radiosurgery, and conservative management for unilateral vestibular schwannoma. Clin Otolaryngol 2004; 29: 621-627

The best way to manage small and medium-sized vestibular schwannomas is currently a matter of heated debate. As these tumours are not immediately life-threatening, patients are invariably concerned about how management would affect their quality of life. Until now, no study has compared the three treatment modalities in terms of physical, psychological and social well being. This study is based on a retrospective database analysis and postal questionnaire survey of unilateral vestibular schwannoma patients who had either been managed conservatively, or treated with microsurgery or radiosurgery. The results showed that: quality of life (measured by the Glasgow Benefit Inventory) deteriorated after microsurgery, particularly for small tumours; conservative management did not lead to a change in quality of life, and there was a trend towards poorer quality of life following radiosurgery. The findings suggest that a conservative management approach may be more appropriate for small tumours, and that patients who are due to undergo microsurgery or radiosurgery may benefit from counselling about the potential impact of treatment on quality of life.

Seth J. Kanowitz, William H. Shapiro, John G. Golfinos, Noel L. Cohen, J. Thomas Roland, Jr. Auditory brainstem implantation in patients with neurofibromatosis type 2. Laryngoscope 2004; 114: 2135-2146

Objectives: Multichannel auditory brainstem implants (ABI) are currently indicated for patients with neurofibromatosis type II (NF2) and schwannomas involving the internal auditory canal (IAC) or cerebellopontine angle (CPA), regard-less of hearing loss (HL). The implant is usually placed in the lateral recess of the fourth ventricle at the time of tumor resection to stimulate the cochlear nucleus. This study aims to review the surgical and audiologic outcomes in 18 patients implanted by our Skull Base Surgery Team from 1994 through 2003.

Study Design: A retrospective chart review of 18 patients with ABIs.

Methods: We evaluated demographic data including age at implantation, number of tumor resections before implantation, tumor size, surgical approach, and postoperative surgical complications. The ABI auditory results at 1 year were then evaluated for number of functioning electrodes and channels, hours per day of use, nonauditory side effect profile and hearing results. Audiologic data including Monosyllable, Spondee, Trochee test (MTS) Word and Stress scores, Northwestern University Children's Perception of Speech (NU-CHIPS), and auditory sensitivity are reported.

Results: No surgical complications caused by ABI implantation were revealed. A probe for lateral recess and cochlear nucleus localization was helpful in several patients. A range of auditory performance is reported, and two patients had no auditory perceptions. Electrode paddle migration occurred in two patients. Patient education and encouragement is very important to obtain maximum benefit.

Conclusions: ABIs are safe, do not increase surgical morbidity, and allow most patients to experience improved communication as well as access to environmental sounds. Nonauditory side effects can be minimized by selecting proper stimulation patterns. The ABI continues to be an emerging field for hearing rehabilitation in patients who are deafened by NF2.

David R. White, Robert E. Sonnenburg, Matthew G. Ewend, Brent A. Senior. Safety of minimally invasive pituitary surgery (MIPS) compared with a traditional approach. Laryngoscope 2004; 114: 1945-1948

Introduction: Transsphenoidal hypophysectomy is becoming progressively less invasive. Recent endoscopic techniques avoid nasal or intraoral incisions, use of nasal speculums, and nasal packing. Several case series of endoscopic endonasal pituitary surgery have been reported, but relatively little data exists comparing complication rates to more traditional approaches. We compare the complications of our first 50 cases of endoscopic, minimally invasive pituitary surgery (MIPS) to our last 50 subIabial transseptal (SLTS) procedures.

Study Design: Retrospective case control study.

Methods: Fifty consecutive MIPS procedures and 50 consecutive SLTS procedures were reviewed retrospectively. Complication rates were analyzed and compared.

Results: Total complications per patient (P = .005), postoperative epistaxis (P = .031), and deviated septum (P = .028) occurred more often in the SLTS group. No significant difference was seen in cerebrospinal fluid leak, meningitis, ophthalmoplegia, visual acuity loss, diabetes insipidus, intracranial hemorrhage, or death. In the MIPS group, length of stay (P < .001), use of Iumbar drainage (P = .007), and nasal packing (P < .001) were also significantly reduced.

Conclusions: Endoscopic endonasal pituitary surgery provides improved complication rates when compared with SLTS approaches. In addition, we note advantages of the MIPS approach, including reduced length of hospital stay and decreased use of lumbar drainage and nasal packing.

Christopher Danner, Bill Mastrodimos, Roberto A. Cueva. A comparison of direct eighth nerve monitoring and auditory brainstem response in hearing preservation surgery for vestibular schwannoma. Otol Neurotol 2004; 25: 826-832

Objective: The objective of this study was to compare the effectiveness of direct eighth nerve monitoring (DENM) and auditory brainstem response (ABR) in facilitating hearing preservation during vestibular schwannoma resection.

Study Design: This was a retrospective study.

Setting: Tertiary referral center.

Method: We conducted a retrospective clinical study of the use of ABR and DENM during vestibular schwannoma removal. Tumors were removed through a retrosigmoid craniotomy. The rate of hearing preservation between the two monitoring modalities was compared. The additional outcome measures of facial nerve function and cerebral spinal fluid leak rate were also evaluated.

Results: Hearing preservation was attempted in 77 patients with vestibular schwannomas. Tumor sizes ranged from 0.5 cm to 2.5 cm. Hearing was preserved in 71% of patients with tumors 1 cm or less and in 32% of patients with tumors between 1 and 2.5 cm when direct eighth nerve monitoring was used. Hearing preservation rates with ABR for tumors 1 cm or less were 41% and 10% in patients with tumors between 1 and 2.5 cm (p = 0.03) Facial nerve preservations rates were 94% (House-Brackmann 1-2) for tumors less than 2 cm.

Conclusions: DENM provides significantly higher rates of hearing preservation during vestibular schwannoma resection when compared with ABR.

Mario Sanna, Paolo Piazza, Giuseppe DiTrapani, Manoj Agarwal. Management of the internal carotid artery in tumors of the lateral skull base: Preoperative permanent balloon occlusion without reconstruction. Otol Neurotol 2004; 25: 998-1005

Objective: To present our experience with permanent preoperative balloon occlusion of the internal carotid artery while dealing with different abnormalities of the lateral skull base and a comparison with the results mentioned in the literature.

Study Design: Retrospective case review.

Setting: Private neurotologic and skull base tertiary referral center.

Patients: Fifteen patients who underwent preoperative balloon occlusion of the internal carotid artery and surgery subsequently for various abnormalities of the lateral skull base between 1989 and 2002.

Interventions: Each patient was subjected to four-vessel angiography along with the manual cross-compression test and balloon test occlusion to assess the efficacy of the collateral circulation. After angiography, each patient underwent a preoperative balloon occlusion, after which a lateral skull base procedure was performed for removal of the abnormality.

Main Outcome Measures: Only those patients showing evidence of adequate collateral cerebral circulation and a less than 1-second delay between the angiographic phases of the two cerebral hemispheres on angiography were considered fit for preoperative balloon occlusion. While under going the preoperative balloon occlusion, the patients were clinically assessed for the development of any neurologic symptoms and signs. Long-term follow-up after surgery was also based on the development of symptoms and signs of neurovascular compromise.

Results: A major complication in the form of long-lasting hemiplegia occurred in one patient (6.7%). This complication was the result of technical factors rather than an effect of cerebral ischemia, because it was caused by an intimal dissection produced by the catheter. A defect in the visual field occurred in one patient (6.7%) that resolved partially after antiplatelet therapy. There was no mortality in our series related to preoperative balloon occlusion of the internal carotid artery.

Conclusion: Preoperative balloon occlusion of the internal carotid artery can still be considered a viable option for the management of the internal carotid artery during lateral skull base surgery. Proper preoperative evaluation of the adequacy and efficacy of the collateral cerebral circulation reduces the chances of postoperative neurovascular complications.

Mario Sanna, Yogesh Jain, Giuseppe De Donato, Rohit, Lorenzo Lauda, Abdelkader Taibah. Management of jugular paragangliomas: The gruppo otologico experience. Otol Neurotol 2004; 25: 797-804

Objective: The objective of this study was to review the outcome of surgical management in patients of jugular paragangliomas.

Study Design: We conducted a retrospective case review.

Setting: Tertiary care otology and skull base center.

Materials and Methods: Fifty-five patients with the diagnosis of a jugular paraganglioma (Fisch Class C and D Glomus Jugulare) were managed over a period of 15 years. All patients with adequate follow up and complete records (53 cases) were reviewed with emphasis on the results of surgical management and the factors influencing them.

Intervention: All 53 patients were managed with a view to surgically extirpate the tumor. The primary approach was the infratemporal fossa approach-Type A used in the majority of the patients. In eight cases, the procedure was staged owing to the presence of large intracranial extension. Three patients required additional procedures to ameliorate the after-effects of lower cranial nerve resection.

Results: Gross total tumor removal was achieved in 49 patients. There were five cases of recurrence. Coupled with the residual tumors in five patients, the surgical control achieved was 83%. There was no perioperative mortality. There were two cases of postoperative cerebrospinal fluid leak, both of which required surgical exploration and closure. The facial nerve was resected in seven patients. The overall preservation rate of clinically uninvolved lower cranial nerves was 75%.

Conclusions: The low level of complications along with a high surgical control achieved makes surgery the primary mode of treatment in the vast majority of these tumors, regardless of the size and location.

Susan E. Coulson, Nicholas J. O'Dwyer, Roger D. Adams, Glen R. Croxson. Expression of emotion and quality of life after facial nerve paralysis. Otol Neurotol 2004; 25: 1014-1019

Objective: To investigate the facial expression of emotion and quality of life in patients after long-term facial nerve paralysis.

Study Design: Cross-sectional.

Patients: Twenty-four patients with facial nerve paralysis and 24 significant others (partner, relative, friend).

Intervention: Patients were assessed using Sunnybrook, Sydney, and House-Brackmann grading scales and SF-36, Glasgow Benefit Inventory, and Facial Disability Index quality-of-life measures.

Results: When patients identified themselves as either effective or not effective at facially communicating each of Ekman's primary emotions (happiness, disgust, surprise, anger, sadness, and fear), 50% classified themselves as not effective at expressing one or more of the six emotions. Significant others of the not effective patients rated the emotions as more difficult for their partner-patients to communicare facially than did the significant others of effective patients. The SF-36 quality-of-life survey revealed lower social functioning relative to physical functioning for not effective patients. From the Sunnybrook Facial Grading System, more synkinesis was found for those patients not effective at expressing happiness, less brow and eye movement for patients not effective at expressing sadness, and less voluntary movement for those not effective with surprise.

Conclusion: Movement deficits associated with expressing specific emotions and an association with quality-of-life measures were identified in patients with long-term facial nerve paralysis who saw themselves as not effective at facial expression of emotions. To improve management of emotional expression in patients with facial nerve paralysis, a broader approach is recommended, linking the practitioner's treatment goals with patient-driven outcome goals.

Ricardo F. Bento, Rubens V. de Brito. Gunshot wounds to the facial nerve. Otol Neurotol 2004; 25: 1009-1013

Objective: This paper presents our experience with gunshot wounds to the temporal bone and discusses facial nerve lesions.

Study Design: We performed a retrospective review of patients treated for facial nerve lesion after gunshot injury to the temporal bone.

Setting: The study was performed in the Otolaryngology Department of the University of São Paulo Medical School, São Paulo, Brazil.

Patients: Ninety-eight patients treated between 1988 and 1999 were analyzed.

Intervention: Facial nerve lesions, bullet locations, and surgical techniques were analyzed. Patients were monitored for 2 years.

Results: Gunshot trauma to the temporal bone presented considerable tissue loss resulting from the abrasion effect and severity of the impact. The third segment of the facial nerve was most affected, and the bullet was typically found lodged in the mastoid tip. Postoperative infection was common. Such cases required revision surgery, resulting in worse cosmetic outcomes than in cases of closed trauma.

Conclusion: Surgical exploration of the facial nerve should be performed as soon as possible, since long delays increase the chance of traumatic neuroma and more pronounced scarring around the facial nerve. Open mastoidectomy with meatoplasty is the surgical technique recommended for repairing the mastoid and the facial nerve. In the majority of cases, a cable graft is necessary. Since nerve lesion in proximity to the stylomastoid foramen and extratemporal facial nerve is common, these areas must be explored carefully.

Brian F. O'Reilly, Ameet Kishore, John A. Crowther, Colin Smith. Correlation of growth factor receptor expression with clinical growth in vestibular schwannomas. Otol Neurotol 2004; 25: 791-796

Objective: To examine the relationship between growth rate of vestibular schwannomas and the expression of various growth factor receptors.

Study Design: Retrospective case review of clinical growth rate in conjunction with a histopathologic and immunohisto-chemical reexamination of archival specimens.

Setting: A tertiary referral neurotologic center.

Patients: Three groups: a historical group to act as controls, consisting of 30 patients with sporadic vestibular schwannomas removed before the unit adopted an initial interval scan policy; a group of 14 patients with sporadic vestibular schwannomas who had undergone an initial interval scan policy, showed radiologic evidence of growth, and therefore had their schwannoma removed: and a group of 16 schwannomas removed from 11 neurofibromatosis Type 2 patients.

Main Outcome Measures: A comparison between the three clinical groups using immunohistochemical studies to determine the level of expression of the proliferation factor Ki-67, c-erbB-2, and c-erbB-3 receptors and fibroblastic growth factor receptors 1 and 4.

Results: The level of expression of the proliferation factor Ki-67 was very low and similar in all three groups. C-erbB-2 and c-erbB-3 receptors were not expressed in any of the groups, fibroblastic growth factor receptor 4 expression was not significantly different, but there was a variation in the expression of fibroblastic growth factor receptor 1 between the three groups that correlated well with the differing incidence of growth in the groups. The increase in expression of fibroblastic growth factor receptor 1 in the neurofibromatosis Type 2 group was not statistically significant, but the increase in expression of fibroblastic growth factor receptor 1 in the growing sporadic group was statistically significant when compared with the historical controls. The level of fibroblastic growth factor receptor 1 expression correlates significantly with the rate of growth as measured on interval magnetic resonance imaging.

Conclusions: Overexpression of fibroblastic growth factor receptor 1 has a positive correlation with the incidence and the rate of growth of sporadic vestibular schwannomas.