Severe radionecrosis of the temporal bone is a potentially lethal condition which still occurs despite improvements in radiotherapy.

A Series of seven such cases is presented to outline the varied clinical features and management of this disease.

Twelve deaf adults and two deaf children were treated with the Ineraid (formerly Symbion) four channel intracochlear implant between September 1989 and October 1991 at Addenbrooke's Hospital in Cambridge. All were post-lingually totally deaf and had found themselves beyond the reach of hearing aids. The effect of the implant upon the patients ability to lip-read was tested with the speech tracking test, BKB sentences (comparable to CID sentences) and Boothroyd word lists (comparable to NU6 word lists). All patients showed an improvement in their ability to understand speech with the help of the implant. Discrimination of speech without lip-reading was tested with Boothroyd word lists and BKB sentences, eight patients (57 per cent) demonstrated some ‘open set’ speech discrimination. The acceptability of the carbon percutaneous pedestal is discussed from the patient's, audiologist's and surgeon's points of view.

Following stimulation of one ear with white noise (WN) or 0.5, 1 and 2 kHz tone bursts a statistically valid mean reduction in the amplitude of delayed evoked otoacoustic emissions (DEOE), elicited from the contralateral ear by bursts of the same frequencies, was observed in 10 people (19–23-years-old) with normal hearing. This reduction only appeared in response to a contralateral stimulus delivered 7, 8 and 9 ms earlier than that used to produce the DEOE. This inhibitory effect was just referable to the activity of the medial olivocochlear efferent system (MOES). This research has shown that: (i) the cochlear interdependence is linked to activation of the MOES; (ii) in man the activity of MOES is inhibitory and only appears for a stimulus of the same frequency or (for WN) including that used to elicit DEOE; (iii) the cochlear interdependence is frequency selective and the MOES thus establishes a direct functional interdependence between homologous sectors of the organs of Corti on the two sides; (iv) DEOE would appear to be no more than partly generated by outer hair cells (OHC) of the organ of Corti in relation to the frequency of the stimulus employed, thus substantiating the hypothesis that in their production the effects of an 'active' mechanism, represented by the 'slow' contractile activity of the OHC, is overlain by those of a 'passive' mechanism formed by the oscillations induced by the movements of the stapes in the basilar membrane (BM) or in the set of membranes and liquids of cochlear canal.

A stratified random cluster sample of 15,845 subjects was performed in two regions of Nepal to determine the prevalence and main causes of hearing impairment (the most common disability) and the prevalence of ear disease. Subjects reporting current ear pain, or ear discharge, or hearing impairment on direct questioning by a Nepali health worker (primary screening failed), had otoscopy and audiometry (using the Liverpool Field Audiometer) performed, and a questionnaire administered relating to past history. In every fifth house subjects who passed the primary screening (1,716 subjects) were examined to assess the false negative rate of screening. An estimated 16.6 per cent of the study population have hearing impairment (either ear worse than 30 dB hearing threshold level (HTL) 1.0–4.0 kHz, or 50 dB HTL 0.5 kHz), and 7.4 per cent ear drum pathology, equivalent to respectively 2.71 and 1.48 million people extrapolated to the whole of Nepal. Most hearing impairment in the school age group (55.2 per cent) is associated with otitis media or its sequelae. Probably at least 14 per cent of sensorineural deafness is preventable (7 per cent infectious disease, 3.9 per cent trauma, 0.8 per cent noise exposure, 1 per cent cretinism, and 1 per cent abnormal pregnancy or labour). Most individuals reporting current ear pathology (61 per cent) had never attended a health post, and of those receiving ear drop treatment, 84 per cent still had serious pathology. Of subjects who reported ear drop treatment at any time, 31 per cent still had serious pathology. The use of traditional remedies was prevalent.

In conclusion this study shows high prevalences of hearing impairment and ear drum pathology. To reduce hearing impairment in Nepal, particularly in the school age group, a priority should be the effective treatment of otitis media.

This prospective randomized study investigates whether the use of antibiotic/steroid ear drops (Betnesol-N) is effective in reducing early post-operative otorrhoea and blockjage of ventilation tubes (VTs). The study included 162 children who had bilateral VT insertion and used Betnesol-N ear drops in one ear only for three days after surgery, the other ear was left as cotrol. These children were reviewed two weeks later and their ears wer examined for VT patency, presence of blood or of mucopus. Statistical analysis of our results showed that the use of Betneso-N ear drops has significantly reduced the incidence of post-operative otorrhoes within two weeks of VTs insertion (p<0.01). However, these drops dids not have a significant effect on the blockage rates of VTs with dried bolld (p>0.05).

The Cochlear Implant Programme at Manchester Royal Infirmary was established in 1988 and so far (January,1992) 38 patients have been implanted with the Nucleus 22 channel intracochlear device and one with the Ineraid device. All patients who are referred for consideration for an implant are initially seen at a preliminary cochlear implant assessment clinic conducted by an ENT surgeon. One hundred and seventy three patients attended the initial outpatient screening clinic between 1987 and January 1992. Of these 112 patients (67.6 percent) went on for further investigation regarding suitability for implantation. This paper details the aetiology and severity of deafness in these patients and explains how suitability for admission to the next stage of assessment was decided.

The neurofibromatoses consist of at least two distinct autosomal dominant hereditary disorders. Neurofibromatosis type 1 (NF1) is due to a lesion on chromosome 17q. Neurofibromatosis type 2 (NF2) is caused by a defect on chromosome 22q. The hallmark of NF2 is the development, in the second and third decades, of bilateral acoustic neuromas. NF1 is characterized by the appearance of cafe-au-lait spots and neurofibromas in addition to iris hamartomas, or Lisch nodules, of the eye, during the first and second decades.

Ten families were personally studied. A total of 16 members were found to be affected with NF2. A protocol for evaluation and review of subjects and relatives of NF2 families is proposed. A team approach, coordinating the expertise of multiple specialties is recommended.

Amplitude of the Nl component of the cortical response was used to objectively determine threshold of hearing at 1 kHz and 4 kHz in a series of consecutively referred medicolegal cases with alleged occupational noise induced hearing loss and a control group of patients with Ménière's disease who were not seeking compensation for their hearing loss. The cortical response thresholds were compared with the subjective pure tone audiometric (PTA) thresholds at the same frequencies. The cortical and PTA thresholds were ‘;within 10 dB’; for 84 and 92 per cent of the cases of noise induced hearing loss (NIHL) and Ménière's disease respectively, confirming the validity of CERA as a means of denning accurately the frequency specific thresholds and the audiometric configuration. Of the remaining 16 per cent of NIHL, 13 per cent exaggerated their PTA thresholds at 1 kHz and 10 per cent at 4 kHz whilst the error in cortical threshold estimation was beyond the 10 dB level for three and six per cent of cases at those frequencies respectively. The median exaggeration of threshold was 25 dB. For eight per cent of the Ménière's patients, thresholds exceeded 10 dB at both 1 and 4 kHz, four per cent of whom exaggerated their PTA thresholds and four per cent had a test error greater than 10 dB. A similar percentage (four per cent) of both groups revealed a cortical test error greater than 10 dB whereas three times as many cases of noise induced hearing loss (13 per cent) revealed exaggeration of their subjective audiometric thresholds compared with the Ménière's group (four per cent).

The value of latency criteria in the assessment of cortical threshold was established. The latency of Nl close to threshold was invariably greater than 150 ms and at 30 dB above threshold, irrespective of absolute levels, it was within 10 ms of 100 ms, thereby providing another criterion for the improved measurement of threshold.

The incidence of persistent perforation following grommet removal or extrusion in 210 ears was assessed, and found to be zero per cent. Collar button grommets were retained longer than Shepard grommets, and the percentage of ears requiring two or more tube insertions was 51.9 per cent.

A prospective study was undertaken of 10 chronic renal failure patients on Continuous Ambulatory Peritoneal Dialysis (CAPD) complicated by repeated bouts of peritonitis treated with gentamicin. Each 10-day treatment course consisted of a 120 mg loading dose, followed by 16 mg in 21 of peritoneal dialysate, given four times a day. Serum gentamicin analysed by enzyme immunoassay showed a mean level of 5.2 µg/ml, (range 3.7 to 6.6 µg/ml) four hours after the loading dose. Similar levels, well within the therapeutic range, were maintained on the 3rd, 5th, 7th and 9th days of intraperitoneal gentamicin therapy, suggesting no accumulation of gentamicin in the serum. Pure tone audiometry, electronystagmography and clinical assessment were performed during each course of treatment. Although no evidence of ototoxicity was found during the first two courses of gentamicin, but disequilibrium and bobbing oscillopsia were present during the third and fourth courses of gentamicin. These findings could be explained by cumulative injury to the vestibular apparatus caused by repeated therapeutic insults.

Histological data concerning the structure and the topographical distribution of the eustachian tube submucosal glands is presented in 94 serially-sectioned temporal bones with and without otitis media. The vast majority of the tubal glands are located adjacent to the nasopharynx in the pharyngeal and midportion regions. Mixed glands which contain equal amounts of mucoid and serous elements are found in all age groups, in most specimens, either with or without otitis media. Furthermore, the glandular tissue, along these two medial regions of the tube, does not disclose significant quantitative differences between normal and inflamed specimens. Temporal bones without otitis media harbour few glands in the lateral four regions of the tube, while those with otitis media show a moderate increase of gland formation which is more noticeable in the pretympanum than in the regions around the isthmus (pre-isthmus, isthmus and post-isthmus regions). It is apparent that chronic inflammatory conditions like simple chronic otitis media and secretory otitis media are more often accompanied by gland formation, along the lateral four regions of the tube than acute otitis media.

The results of a U.K. study of 145 cases of type 2 neurofibromatosis has shown generally very poor operative results in terms of hearing and facial nerve preservation. Only 9 out of 118 vestibular schwannoma (acoustic neuroma) operations resulted in any clinically detectable hearing preservation and only 32 left the patient with good or normal (House grade I or II) ipsilateral facial nerve function. Although operation is still the definitive treatment of vestibular schwannoma (acoustic neuroma) and may be a lifesaving procedure, it appears that the evidence in favour of early operation is only valid when carried out in highly specialized centres. The special problems of NF2 cases who may go on to develop multiple spinal and cranial tumours making them wheelchair bound and blind as well as deaf warrants a careful experienced approach. Timing of operations may be critical for the enhancement of useful years of quality life. We therefore propose the setting up of a national NF2 register, with the management of cases at a few supraregional centres.

This retrospective study compares the tympanoplasty success rate when using a xenograft (Zenoderm) or an autograft (temporalis fascia).

Fifty-three ears were operated on over a three-year period. All the tympanoplasty operations were performed by the same surgeon. There were 43 ears in the temporalis fascia autograft group and 10 ears in the Zenoderm xenograft group. Both groups were similar with respect to patient age, type of tympanoplasty, area of tympanic membrane perforation and condition of the contralateral ear.

The tympanoplasty success rate in the temporalis fascia autograft group was 95 per cent. The tympanoplasty success rate in the Zenoderm xenograft group was only 40 per cent. All Zenoderm tympanoplasty failures were regrafted with temporalis fascia autograft. There was a 100 per cent success rate with this salvage surgery.

In conclusion, we suggest that Zenoderm is not a suitable graft material for tympanoplasty.

Antibodies to type II collagen have been reported by some authors to be raised in patients with Ménière's disease. In this study the antibody levels to type I and II collagen have been measured in 37 patients with Ménière's disease and 20 controls, using a solid-phase, double-antibody, enzyme-linked, immunoassay. No significant difference in antibody levels between the two groups was found. These findings do not support previously reported work which suggests that some cases of Ménière's disease are due to type II collagen autoimmunity.

The purpose of this investigation was to establish the incidence of clinical otoscierosis and auditory exostoses in Lithuanian paleopopulations. The total sample consists of 4080 skulls, dating from the Neolithic to the C 17th—C 18th a.d., investigated visually, under magnification and radiologically. Eight cases of clinical otosclerosis and 22 of auditory exostoses were identified. The general epidemiology of otosclerosis (0.19 ± 0.08 per cent) was established to be similar to contemporary populations. This suggests that there are no new aetiological factors attributable to our modern society. Clear diminution of the incidence of auditory exostoses from the 1st to the 2nd millenium A.D. (3.46 ± 0.76 per cent, against 0.06 ± 0.04 per cent, p <0.001) and definite sexual differences (males: 1.21 ± 0.28 per cent; females: 0.17 ± 0.10 per cent, p<0.001) were also noted. In general, auditory exostoses were found much more frequently than in recent populations.

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.

Speech audiometry was performed on 15 children with secretory otitis media pre-and post-operatively and the findings compared with the pre-and post-operative pure tone audiograms. The results showed that in 30 per cent of cases pre-operatively the speech audiogram suggested a significantly worse hearing ability than that suggested by the pure tone audiogram (PTA). Where a PTA gives a borderline threshold disproportionate parental concern should be taken seriously as the hearing ability may well be worse than the PTA suggests.

Concern about the possible risk of viral infection being transmitted by the use of homografts has renewed interest in cortical bone autografts as an ossicular substitute. Over the last four years I have used cortical bone on a regular basis. Comparison of hearing results obtained using ossicular and cortical bone grafts shows no significant difference between the two groups. Cortical bone appears to be satisfactory material for ossiculoplasty, but long-term studies of outcome are required to confirm this.

Mucociliary and equipressive eustachian tube functions have been studied, using saccharin solution (five per cent sodium saccharinate) and tubal manometry respectively, in 58 ears with chronic disease undergoing tympanoplasty. The position of the perforation site determines the results as the poorest results are obtained from the posterior ones, positive cases (47 per cent) and mean transport time (37.7 minutes), compared to the greater percentage of positive cases (86 per cent) and mean transport time (22.2 minutes) for anterior perforations.

When both parameters are analysed together there is a direct relationship between normal equipressive function and normal mucociliary transport time and between negative transport time and tubal blocking. Significant differences in transport times have been found for the anterior and posterior perforations being shorter for the anterior ones.

When surgical outcome is correlated with mucociliary transport, the normal transport time percentage is seen to be considerably higher in the success group (50 per cent) than in the failure group (22 per cent).

The effects of keeping rat tympanic membranes with an artificially made pars tensa perforation in tissue culture were observed under a scanning electron microscope. After one day and onwards, spreading and thickening of the keratinizing, outer squamous epithelium (OE) was noted. In addition, ballooning of the innermost cells of the outer epithelium apposing the inner tympanic epithelium (IE) was seen. No appreciable reaction was noted in the connective tissue layer of the drum. The inner tympanic epithelium appeared to be swollen, containing spherical structures in the cytoplasm, especially close to the area of contact with the outer meatal epithelium. No complete cover of the drum defect was seen after 14 days of tissue culture. Hyperplasia and spreading of the keratinizing, outer squamous epithelium of the drum is not sufficient to achieve covering of a drum perforation and complete healing cannot take place unless supported by granulation tissue formation.