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Objective: Trigeminal neuromas are rare tumours that may involve any part of the Vth nerve complex, including extracranial peripheral divisions of the nerve. A series of eight patients with intracranial trigeminal neuromas who underwent surgical management are presented.Methods: The hospital records and radiological images were reviewed with regard to clinical presentation, surgical approach, operative findings, peri-operative morbidity and neurological outcome, and percentage of tumour recurrence.Results: The principal presenting symptoms were those of involvement of the trigeminal nerve with sensory impairment in one or more of the three divisions. Tumour location was the prime determinant of surgical approach. Lateral skull base approaches were used as they are considered to be superior for identifying tumour origin, extension, and relationship to surrounding structures. Total excision of the tumour was carried out in three of the eight patients. In the remaining five patients some tumour was left purposely in order to minimize neurological deficit and optimize post-operative quality of life. There was no peri-operative mortality or major morbidity in our series. Five patients experienced symptomatic tumour recurrence and revision surgery was performed.Conclusion: Management of trigeminal neuromas is complex and requires a multidisciplinary approach. Pre-operative surgical planning allows tumour removal with preservation of important neural structures in the majority of cases. For large tumours occupying both the middle and posterior cranial fossae, the retrosigmoid/retrolabyrinthine/middle cranial fossa approach provides good exposure and results in minimal brain retraction. A Fisch type C approach is necessary for the largest tumours. Long-term follow up with interval imaging is mandatory to exclude long-term tumour recurrence.

The objective of this study was to review the experience of the Neurotology and Skull Base Surgery Unit of Addenbrooke's Hospital in Cambridge, England, in the management of patients with neurofibromatosis type 2 (NF2). This was a retrospective review of the institution's series conducted at a neurotological tertiary referral centre. Over a 17-year period (1984-2001), 35 patients with NF2 were managed. These patients presented with multiple cranio-spinal neoplasms, including 62 cerebellopontine angle tumours of which 59 were vestibular schwannomas (nine patients with unilateral tumours and 25 patients with bilateral tumours). Clinical presentation, diagnosis and patient management were reviewed. The outcome parameters measured were tumour progression, the incidence of complications (hearing deterioration and facial nerve palsy) and the need for secondary intervention. Five vestibular schwannomas were treated with stereotactic radiosurgery (gamma-knife), all of which showed evidence of progression in size and/or deterioration in hearing. Thirty-one VS were conservatively treated with annual surveillance. In nine cases, the tumours had a follow-up shorter than 6 months and were therefore excluded from the results. In 13 cases the VS did not progress in size, and the hearing remained stable, while in the remaining nine cases, tumour progression was evident. In fifteen cases, surgery was performed at the authors' institution. In 11 cases a translabyrinthine approach was adopted, and in the remaining four cases a retrosigmoid approach was preferred. In all these cases, tumour removal was total and facial nerve function was House-Brackmann grade I-III in 55%. Successful hearing preservation was elusive in those patients in whom a hearing preservation approach was attempted. NF2 remains an extremely challenging disorder for the neurotologist and the patient alike. Early diagnosis offers distinct advantages to the patients, their families and the community at large. Of the treatment modalities, surgery unequivocally offers the most superior tumour control. Hearing preservation remains a challenge in these patients, but is optimised by the early detection of tumours in the NF2 patient.

Objective:To determine factors affecting facial nerve outcome of vestibular schwannoma surgery.Methods:This retrospective cohort study comprised 652 patients. The outcome measure was House–Brackmann classification at two years post-operatively. Univariate and multivariate analyses were carried out to determine the factors affecting facial nerve outcome. The incidence rates of hemifacial spasm, metallic taste and crocodile tear syndrome were recorded.Results:For tumours less than 1.5 cm, 95 per cent of outcomes were normal, 100 per cent were satisfactory (House–Brackmann grades I–III) and 0 per cent were unsatisfactory (grades IV–VI). For tumours 1.5–2.4 cm, 83 per cent of outcomes were normal, 99 per cent were satisfactory and 1 per cent were unsatisfactory. For tumours 2.5–3.4 cm, 68 per cent of outcomes were normal, 96 per cent were satisfactory and 4 per cent were unsatisfactory. For tumours 3.5–4.4 cm, 52 per cent of outcomes were normal, 80 per cent were satisfactory and 20 per cent were unsatisfactory. For tumours larger than 4.4 cm, 50 per cent of outcomes were normal, 72 per cent were satisfactory and 28 per cent were unsatisfactory.Conclusion:Tumour size and operation year were significant predictors of facial nerve outcome. The surgical learning curve was steepest for the first 50 patients.

Objective: To review the treatment of squamous carcinoma of the temporal bone at a regional skull base unit for the period 1982Y2012. Study Design: Retrospective case review. Setting: Tertiary referral center. Patients: Sixty patients with primary squamous carcinoma of the temporal bone. Interventions: Multidisciplinary team approach including surgical resection, reconstruction, and postoperative radiotherapy. Main Outcome Measures: Disease-specific survival, overall survival. Results: The 5-year disease-specific survival for the whole cohort was 44% (CI, 37%Y51%). Multivariable analysis revealed nodal status, poorly differentiated squamous cell histology, and carotid involvement to be poor prognostic indicators. Conclusion: Although the survival figures in this series are comparable with the best outcomes from other units, our experience would suggest improvements can still be achieved by reconsidering the selection of patients for neck dissection and temperomandibular joint excision in early stage disease. We also conclude that postoperative radiotherapy should be delivered to all patients, including surgical salvage cases who may have received previous irradiation. Finally, the minority of patients with poor prognostic features should be offered a more palliative therapeutic approach. Key Words: Radical surgeryVRadiotherapyVSquamous cell carcinomaVTemporal bone. Otol Neurotol 00:00Y00, 2014. Squamous cell carcinoma (SCC) affecting the temporal bone region is an aggressive malignancy with a poor prognosis. The reported incidence is less than 6 cases per million per year, which accounts for 0.3% of all cancers within the head and neck, with a reported 5-year diseasespecific survival ranging from 19% to 48% (1Y3). Risk factors for SCC within the epithelium of the temporal bone are previous radiotherapy treatment and chronic suppurative otitis media (CSOM) (4,5). Exposure to ul

Objective: To quantify the postoperative quality of life in patients following surgical treatment for vestibular schwannoma. Study Design: Patient self-assessment using the short form 36 (SF36) multidimensional quality of life health questionnaire. Sex- and age-matched normalized scores were calculated using a standardized process and accepted normative data. Setting: Tertiary referral skull base unit. Results: An 80% response rate (90 patients) was achieved. The postoperative quality of life in vestibular schwannoma patients, as quantified by seven of the eight SF36 health scales was less than the appropriate matched healthy standard. Comparison of a variety of preoperative patients and tumor factors-different operative approaches (translabyrinthine and retrosigmoid), tumor size (group cut of points of tumor diameter 1.5 mm and 2.5 mm), patient sex, and ranking of patient age-showed no statistically significant difference in measured quality of life outcomes for each of these traditional predictors. Conclusion: Reduced quality of life in patients after surgical treatment for vestibular schwannoma, coupled with the low tumor growth rates and minimal preoperative symptoms, supports a conservative approach to patient management. The advantages and disadvantages of a variety of approaches used to measure the quality of life after surgical treatment of vestibular schwannoma and their impact on clinical decision making for patients, are discussed.

With increasing refinement in the surgery of vestibular schwannoma the aims of complete tumor removal and facial nerve preservation have been largely fulfilled. However, the reputation of and place for hearing-preservation surgery still remain uncertain. A major part of this uncertainty is the result of difficulties in interpretation of the various reported results of hearing-preservation surgery. Meaningful comparison between series is difficult because of the varied number of postoperative reporting criteria commonly in use today. Although it is acknowledged that the postoperative reporting criteria affect the hearing-preservation rates, what is not readily appreciated is that preoperative selection criteria for hearing-preservation cases can also significantly affect the success rate of hearing-preservation acoustic neuroma surgery. This article models the many possible outcomes of hearing-preservation schwannoma surgery by use of the previously reported Cambridge series as an illustrative example. With these models some understanding can be gained of the effect of choosing various preoperative and postoperative hearing criteria on the overall hearing-preservation success rate.

The aim of this study was the determination of the incidence of symptoms of audio-vestibular dysfunction and of abnormalities on audio-vestibular testing in patients found to have a unilateral meningioma of the cerebello-pontine angle (CPA). The case notes of 25 patients diagnosed with unilateral, sporadic and histologically proven CPA meningioma were retrospectively reviewed. The age range of this series was 31–71 years, with a mean age of 50 years. Two patients were male (eight per cent) and 23 were female (92 per cent). The mean length of history was 44.7 months. The distribution of tumour size was skewed toward larger tumours, with 15 cases (60 per cent) having tumours with a maximum diameter greater than 3.5 cm on imaging. Pure tone audiometry was normal in five cases (20 per cent), and no patients exhibited the high frequency sensorineural hearing loss that is characteristic of vestibular schwannoma. Speech audiometry was normal in 50 per cent of cases. Caloric testing was abnormal in 77 per cent of the 18 cases tested, whilst auditory brainstem responses (ABR) were abnormal in 100 per cent of the 18 cases who had sufficient hearing for this test to be possible. The presence of normal audiometry in patients with a proven CPA lesion indicates that, if in a protocol for investigation, asymmetry of hearing is mandatory then some pathology will be missed. Any suspicion of a CPA lesion warrants investigation even in the absence of hearing loss.The investigation of choice for the identification of CPA lesions has become magnetic resonance imaging (MRI). If this technique is not available then this study indicates that ABR is a suitable and sensitive investigation. It should be borne in mind however that the data in this study has been derived from a series of predominantly large tumours, and the sensitivity of ABR to smaller CPA meningiomata may fall, as is the case for vestibular schwannoma.

The aim of this study was to assess the surgical results of a series of patients from this unit who underwent extended temporal bone resection for recurrent squamous cell carcinoma as a salvage procedure.The surgical records of 15 patients were analyzed in detail. Each patient had salvage surgery in the form of an extended temporal bone resection with supraomohyoid block dissection, dural grafting, and free microvascular forearm or scalp rotation flap repair for recurrent squamous cell carcinoma in a radical mastoid cavity.Radical surgery yielded a 47% 5-year survival. Twenty-nine percent of the survivors had temporal lobe involvement that necessitated a partial excision of the temporal lobe of the brain. Histologic evidence of local lymph node involvement in the supraomohyoid neck dissection was present in 13% of cases. Those who died did so in the first postoperative year. All those with poorly differentiated tumors died. The survivors had well or moderately differentiated tumors.Radiotherapy alone or partial temporal bone resection, most commonly a radical mastoidectomy with or without preoperative or postoperative radiotherapy is used by the majority of otolaryngologists in treating squamous cell carcinoma of the temporal bone. The 5-year survival rate after this treatment remains depressingly low and the prognosis gloomy, particularly for advanced tumors. The findings in this series of extended temporal bone resections as salvage surgery in recurrent disease is encouraging, and radical surgery combined with radiotherapy from the outset may give much better 5-year survival figures in the future than the conventional partial temporal bone resection and radiotherapy. (Otolaryngol Head Neck Surg 1997;116:617-23.).

A series of 276 patients with a unilateral vestibular schwannoma has been analysed with respect to the factors affecting post-operative facial nerve outcome. Age, tumour size, operative approach and the use of intra-operative facial nerve monitoring have been examined. The tumours were removed via either a translabyrinthine or a retrosigmoid approach. In this series increasing age and increasing tumour size were associated with a worse facial nerve outcome. The use of intra-operative facial nerve monitoring and the retrosigmoid approach were both associated with a better facial nerve outcome. Those patients having a retrosigmoid approach had a facial nerve result that was over one House grade better than those having translabyrinthine tumour removal.

Vestibular schwannomas account for 84% of cerebellopontine angle (CPA) lesions. The remaining CPA tumours comprise a fascinating group of lesions which may present in a similar fashion. Fortunately, advances in neuroradiology have increased our diagnostic accuracy of these lesions. This paper describes the surgical results of a series of 69 CPA lesions which were not vestibular schwannomas. The majority of these unusual CPA tumours were meningiomas, cholesteatomas and neuromas of other cranial nerves in the posterior fossa.

Objective: Acoustic neuroma, both familial and sporadic, is clinically and biologically a heterogeneous condition with a wide variation in age of presentation, length of history, and tumor growth rate. In an attempt to correlate this clinical diversity with the underlying molecular pathology, we have analyzed 43 paired blood-tumor DNA samples from patients with acoustic neuromas. Design: Molecular genetic analysis. Setting: Molecular genetic research laboratory. Patients: Paired blood-tumor DNA samples were obtained from 43 patients (41 sporadic and two patients with neurofibromatosis type 2). Main Outcome Measures: Loss of constitutional heterozygosity was looked for in the region of tumor suppressor genes on chromosomes 3p, 5q, 11p, 17p, 17q, and 22. Results: We found loss of heterozygosity exclusively for markers on chromosome 22. Thirty-nine percent of tumors showed allele loss, and in each case the loss of heterozygosity included the region of the neurofibromatosis type 2 (NF2) gene. No loss of heterozygosity was detected in the region of known or putative suppressor genes in chromosomes 3p, 5q, 11p, 17p, and 17q. Conclusions: This study has demonstrated that (1) chromosome 22 allele loss is a frequent event in sporadic acoustic neuroma; (2) the minimal region of loss of heterozygosity in acoustic neuroma includes theNF2gene; (3) the known tumor suppressor genes investigated (VHL, adenomatous polyposis coli, WT2, p53, and NF1) do not appear to be important in the pathogenesis of acoustic neuroma; and (4) patients with extensive chromosome 22 loss tended to be younger and with a slightly shorter clinical history than those with no detectable allele loss. (Arch Otolaryngol Head Neck Surg. 1993;119:1222-1228)

Cavernous haemangiomas are rare lesions of the cerebello-pontine angle that can mimic the more commonly occurring vestibular schwannoma. A case report involving a patient with a cavernous haemangioma of the internal auditory canal (IAC) highlights this as a diagnostic possibility for lesions of the IAC by comparing and contrasting the clinical and radiological findings with the more commonly occurring vestibular nerve and facial schwannomas.Symptoms such as hearing loss and facial paralysis that are disproportionate to the size of the lesion or fluctuate with hormonal changes such as those seen in pregnancy are suggestive of haemangioma. Radiological imaging demonstrating a lesion enchancing with gadolinium and containing areas of calcification is also suggestive of haemangioma. It is important to consider the possible diagnosis of haemangioma as early recognition of this entity may improve the chances of preserving the functional integrity of the facial nerve.

Internal carotid artery aneurysms are a rare cause of pulsatile tinnitus and conductive hearing loss but should be borne in mind when there is a suspected diagnosis of glomus jugulare or high-riding jugular bulb. Most cases are congenital. We present a case of otorrhagia which was initially thought to be a glomus jugulare, the diagnosis of internal carotid artery aneurysm was made at angiography and treated by balloon embolization.

This paper evaluates the outcome of retrosigmoid microvascular decompression of the facial nerve in a series of patients suffering from hemifacial spasm who had been referred to the skull-base team (comprising senior authors DAM and DGH). The paper is a retrospective review of 15 patients who underwent retrosigmoid microvascular decompression of the facial nerve at Addenbrooke's Hospital between 1985 and 1995. In this series it was possible to obtain complete resolution of hemifacial spasm in 93.3 per cent of cases in the short term and in 80 per cent in the long term. Twelve patients (80 per cent) were symptom-free post-operatively. Two patients had minor recurrence of symptoms occurring within six months of the procedure. One patient with no identifiable vascular impingement of the facial nerve had no improvement following surgery. Three patients suffered sensorineural hearing loss. Two patients complained of post-operative tinnitus, and transient facial palsy was noted in one patient.Retrosigmoid microvascular decompression of the facial nerve provides excellent long-term symptom control in a high percentage of patients with hemifacial spasm.

Objectives/Hypothesis: The objective was to analyze the clinical data and outcome of all the patients treated surgically for squamous carcinoma of the temporal bone in a tertiary referral department of skull base surgery over a 20-year period. Study Design: Retrospective. Methods: Thirty-nine patients with squamous carcinoma of the temporal bone were analyzed. The patients were staged according to the University of Pittsburgh system. The surgical technique, reconstruction of the surgical defect, postoperative radiotherapeutic treatment, follow-up regimen, and results were all described in detail. Results: Disease-free survival for T2N0M0 tumors or stage II disease was 100%. The survival for stage III disease was also 100%. Overall, T3 tumors resulted in 50% survival. Overall, survival for stage IV tumors 34.3%, and for T4 tumors, 38%. Conclusion: The overall disease-free survival for the entire series was 43.2%. Node-positive disease, poorly differentiated squamous cell histological findings, brain involvement, and salvage surgery were associated with a poorer outcome. The improved survival (66%) of patients treated de novo in the study series compared with those treated with salvage surgery (33%) suggested that early referral and aggressive primary surgical treatment with postoperative radiotherapy offer the greatest chance of cure.

Primary cerebellopontine angle (CPA) cholesteatoma grows slowly and silently in the subarachnoidal spaces. The diagnosis is often late, when the lesion has reached large dimensions. Surgical removal is the only available therapy. Fifteen consecutive cases of CPA cholesteatoma managed at a tertiary otoneurosurgical referral unit between September 1985 and April 1999 were reviewed. The study population, consisting of seven males and eight females, had a mean age of 44 years of age (range 21-69) at the time of surgery. The clinical, audiological and radiological presentations were examined. The tumours were classified according to the Moffat classification of CPA cholesteatomas. In 67 per cent of cases the presenting symptom was related to the vestibulo-cochlear nerve. The average duration of symptoms was 23 months (ranging from one month-10 years). The hearing preservation approaches were utilized the most (11 cases), while the translabyrinthine approach alone, or in association with a middle fossa craniotomy, was performed in four cases. Tumour removal was total in 12 cases and subtotal in three cases. In cases undergoing hearing preservation surgery the mean pre-operative pure tone average (PTA) for the frequencies 0.5, 1, 2, and 3 kHz was 19.3 dB HL (SD 13.84) and the mean pre-operative speech discrimination score (SDS) was 89.8 per cent (SD 5.97). In 44.4 per cent of patients the hearing was preserved and the mean post-operative PTA was 20.29 dB HL (SD 15.84). In five patients post-operative complications occurred. No peri- or post-operative death occurred in this series, one patient developed a recurrence 15 years after the initial surgery.

A series of 129 patients who had undergone translabyrinthine removal of a unilateral acoustic schwannoma completed a postal questionnaire about pre- and post-operative tinnitus. A simple grading system was devised from which it was possible to determine the likely outcome of translabyrinthine acoustic schwannoma surgery upon tinnitus. The results have been analyzed in detail, and as a result it is possible to advise a patient undergoing this form of surgery that if they have no tinnitus pre-operatively they are unlikely to develop it, and if they do it will not besevere enough to significantly affect their quality of life. If they have mild or moderate tinnitus it is most likely to stay the same, or become less intense. If a patient has severe tinnitus it is very likely to improve and not affect their future quality of life.

The molecular pathogenesis of vestibular schwannoma has been investigated by determining the extent of chromosome 22 loss of heterozygosity in 77 tumors and relating these findings to clinical and immunohistochemical indexes of tumor behavior. Loss of heterozygosity was looked for at eight chromosome 22q loci. Clinical details were obtained in all 77 cases, and a clinical growth index was calculated for each tumor. The proliferative index was estimated in all tumors by using a monoclonal antibody to the proliferating cell nuclear antigen and by calculating the labeling index. Forty percent (31 of 77) of the tumors showed allele loss, and in each case this loss involved the region of the neurofibromatosis type 2 gene. No evidence was found that the presence of chromosome 22 allele loss was associated with the clinical growth index. On the log scale, however, an association was seen between the clinical growth index and the proliferating cell nuclear antigen labeling index p = 0.001). These results suggest that chromsome 22 allele loss is a frequent event in vestibular schwannoma. Tumor behavior, however, appears to be independent of the chromosome 22 mutation. It is proposed that chromosome 22 allele loss and neurofibromatosis type 2 gene inactivation is an early event, possibly involved in the initiation of tumorigenesis in vestibular schwannoma. Tumor growth appears to be independent of this mutation and is likely to be determined by other as yet undefined factors. (Otolaryngol Head Neck Surg 1997;116:426-30.)

The results of facial nerve outcome following vestibular schwannoma removal have generally ignored the sensory component of the nerve. This lack of reporting occurs partly because the distress relating to these functions is less obvious to the surgeon, and partly because the facial nerve grading systems currently used do not include the functions of the nervus intermedius. We have estimated the frequency and nature of abnormalities of nervus intermedius function following vestibular schwannoma removal using a retrospective questionnaire. Questionnaires were mailed to 257 patients and correctly completed and returned by 224 (87%) of the patients. Prior to surgery 5 (2%) of the patients complained of crocodile tears, 9 (4%) noted dryness of the eye, and 15 (6%) complained of an abnormality of taste. Postoperative crocodile tears occurred in 98 (44%), an absence or significant reduction in the production of tears was noted in 162 (72%), and a taste abnormality, either a significant reduction or an alteration in character, was noted in 107 (48%). The onset of crocodile tears approximated to a bimodal distribution, and the recovery of nervus intermedius functions was variable. This study has demonstrated that nervus intermedius abnormalities are common following vestibular schwannoma removal. It also documents their natural history and discusses the underlying pathophysiological mechanisms. We suggest that appropriate preoperative counseling be given to all patients undergoing surgery and that the functions of the nervus intermedius be included in the surgical reporting of facial nerve results in cerebellopontine angle surgery.

The investigation and treatment of vestibular schwannomas is an increasingly specialized area in which major advances have been seen over recent years. The effect of these advances on the referral patterns to a centre specializing in such surgery is reviewed. The proportion of referrals with a known diagnosis has increased substantially, allowing the specialist centre to focus on appropriate management rather than diagnosis. The vast majority of vestibular schwannomas are referred by otolaryngologists. The caseload referred by neurologists or neurosurgeons have different presenting symptoms. The incidence of vestibular schwannoma in the Cambridge district is found to be 1 per 50,000 population per year. This is a higher incidence than that recorded in other studies. This may be due to a tight diagnostic strategy and the high level of clinical awareness of the local general practitioners.

Glomus tumours of the skull base are rare, but as they present with symptoms of hearing loss and tinnitus they are a clinical entity of which audiologists should be aware. This paper describes the findings of the major series of skull base glomus tumours found in the literature, and notes that the contribution of conductive and sensorineural components varies with tumour classification. The reported incidence of hearing loss and tinnitus in glomus tympanicum and glomus jugulare is reviewed and compared with the Cambridge series, in which two tumours were Fisch type A, four type B, two type C and five type D. In each case a mixed hearing loss was found, though the extent of sensorineural impairment was variable. The length of history of tumours limited to the middle-ear was far shorter (mean 8 months) than for more extensive lesions (type B, mean 64 months; C, 48 months; and D, 23 months). Eleven patients (85%) reported the symptom of hearing loss, and 12 (92.5%) of tinnitus, and some patients had experienced these symptoms for some time without seeking the advice of an otologist. It may be concluded that the presence of subjective pulsatile tinnitus or a retrotympanic mass should be considered an indication for an otological opinion, wherein the use of high resolution imaging techniques and arteriography will be considered in conjunction with detailed audiological assessment. Audiologists should be aware of the possibility of glomus tumour in such cases.

Twelve per cent of a series of 284 patients with vestibular schwannoma presented with sudden deafness. If sudden sensorineural hearing loss is present then it is very likely to be the main presenting symptom. The mean length of patients' history is eight months shorter in this group than in the non-sudden deafness group. Sixteen per cent of vestibular schwannoma patients without sudden deafness present with a 'dead' ear whereas 29.5 per cent of those presenting with sudden deafness have total hearing loss. There was no significant difference between the sudden deafness group and the 'all others' group with regard to tumour size, udiogram shape, caloric test, imbalance, and facial numbness. Although the numbers of patients with sudden deafness in this series were too small to reach significance, on the basis of the clinical correlation of vestibular schwannoma morphology it is possible to postulate that compression of the vasculature within the bony internal auditory canal by a laterally arising tumour may be the aetiological factor and may be more likely to occur than in more medially arising tumours.

Fifty-nine unusual cerebello-pontine angle tumours have been studied. These lesions represent 19.3 per cent or 1 in 5 of a series of 305 cerebello-pontine angle tumours of which the rest, 246 (80.7 per cent), were acoustic neuromas. An analysis of the relative incidence, histology and presenting clinical features has been carried out. The various radiographical features and imaging techniques used to diagnose these fascinating tumours have been described and also the otoneurosurgical procedures necessary to excise them.

Thirty–eight patients with vestibular schwannomas were reviewed. A correlation was found between tumour morphology and clinical presentation. Based on our knowledge of the variability in the neurilemmalneuroglial junction and therefore the site of origin of these tumours in relation to the internal auditory canal, a classification into three different appearances on magnetic resonance imaging was possible. Dumbbell shaped tumours (21 per cent) represented laterally arising schwannomas, lollipop shaped tumours (18 per cent) were medially arising and cone shaped tumours (61 per cent) were the more common intermediate form. Patients with laterally arising dumb–bell shaped tumours were more likely to present early with hearing loss and had smaller tumours than patients with medially arising lollipop shaped ones. The relatively well preserved hearing in patients with medially arising tumours made them more likely to present at a later stage with signs of trigeminal compression, cerebellar dysfunction and raised intracranial pressure.

The diagnosis and treatment of petrous apex cholesteatoma is a difficult surgical challenge. This study is a review of 14 cases of cholesteatoma involving the petrous apex. These cholesteatomas originated as a congenital primary lesion or secondary to an acquired lesion. The cases were evaluated according to the clinical features, the intraoperative findings, the radiological findings, and the surgical approaches. In this series, 83% of the patients presented with hearing loss and 50% presented with facial nerve weakness or paralysis (House grade II to VI). Intraoperative and radiological features revealed frequent direct labyrinthine and supralabyrinthine cell spread. The transpetrous surgical approach was used in all cases. The main factors affecting the surgical approach to be adopted are the inaccessible nature of the petrous apex, the extent of disease, the degree of facial nerve function, and the need for the prevention of cerebrospinal fluid leaks and the recurrence of the lesion.

Many procedures have been devised to deal with intractable vertigo and conserve hearing, but despite this selective vestibular nerve section remains by far the most effective treatment.A series of 14 patients who underwent posterior fossa vestibular neurectomy is reported. The results are reported for vertigo control, hearing and tinnitus. All of the patients achieved vertigo control according to the AAOO (1972) reporting system. A simple and reliable system for the classification of the disability in these patients has yet to be devised. This problem is addressed and a disability grading system proposed, and discussed.

A case report of a thrombosed posterior-inferior cerebellar artery aneurysm is described. The tumour masqueraded as a vestibular schwannoma on imaging but the presenting featureswere unusual, the facial pain and weakness predominating despite well preserved hearing. This is an example of a rare cerebellopontine angle tumour and highlights the need for suspicion when lesions present atypically.

A retrospective analysis of 76 patients who underwent acoustic neuroma removal is reported. Facial nerve function prior to surgery and tumour size are assessed with respect to final facial nerver recovery and the need for surgical rehabilitation. Both pre-operative facial weakness and tumour size greater than 2.5 cm. are shown to be predictive factors of poor facial nerve recovery. Multiple surgical rehabilitative procedures are often required when inadequate function and/or cosmetic results are obtained. Primary nerve repair and facial-hypoglossal anastomosis give better rehabilitative results than dynamic and static procedures. The association of tumour size greater than 2.5 cm. with increased risk of poor facial recovery re-emphasizes the need to detect and remove acoustic neuromas at an early stage.

Contralateral Auditory Brainstem Response (ABR) findings in a series of 79 patients with unilateral acoustic neuroma are presented. Sixty-four patients (81 per cent) had a normal contralateral ABR, thirteen (16.4 per cent) had latency abnormalities contralaterally and in two patients (206 per cent) no consistent responses could be recorded despite good hearing. Abnormalities in the contralateral ABR were analysed and five patients had abnormal III-V interwave intervals, in seven patients the I-III intervals were abnormal and in one patient, only the fifth wave was present and of abnormal latency. The tumour size was assessed by computed axial tomography (CT) and the relationship between tumour size and contralateral ABR findings established. Large tumours (>2.5 cm.) were associated with contralateral ABR abnormalities in 25.6 per cent of the patients, medium tumours (1.0-2.5 cm.) with ABR abnormalities in 14 per cent and there were no abnormalities in the small group (intracanalicular). The implications for interpretation of ABR recordings contralateral to an acoustic neuroma are discussed in relation to brainstem compression and its effect on the wave generator sites.

Advances in audiological, radiological and microsurgical techniques have enabled otologists to diagnose and excise very small acoustic tumours with a low morbidity and mortality. Is this cost effective?In an attempt to answer this question, an analysis of 66 cases of surgically treated acoustic neuromas is presented. This represents part of a series of skull base procedures carried out at Addenbrooke's Hospital over the last five years. As a result of this work an investigative protocol is suggested. By studying the relative morbidity of early and late surgical intervention in these cases, and by costing the exercise, the justification for early diagnosis and treatment is presented both in financial and human terms.

In a series of 100 patients with unilateral acoustic neuroma the incidence of mastoid aching was found to be 25 per cent, though none of the patients reported this as their principal symptom. Mastoid ache was not related to tumour size, hydrocephalus, or duration of symptoms. However, there was a significantly higher incidence of facial numbness and diminished facial sensation, but not facial weakness, compared with the whole series. Since motor fibres are more resistant to pressure than sensory fibres, mastoid ache may signify the pressure of an expanding cerebellopontine angle tumour.

A prospective study of 100 patients with a unilateral, subsequently histologically proven, acoustic neuroma seen in the Department of Otoneurosurgery at Addenbrooke's Hospital between 1983 and 1988, demonstrated that Unterberger's Stepping test achieved a higher sensitivity (71 per cent) than the Romberg test (39 per cent). The discrepancy between tests is at a maximum for small acoustic neuromas, and therefore the Stepping test may help in the earlier detection of vestibular abnormalities.