PubMed Health⌕ Search

Biomedical subjects

D A Moffat

Publications and source records attributed to D A Moffat.

At least 73 records · Page 4Linked to original sources
PubMed1994

Sudden deafness in vestibular schwannoma.

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, audiogram 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.

Adult↗
PubMed1994

Surgical emphysema: a novel complication of aural exostosis surgery.

We present the case of a 40-year-old male Caucasian patient who developed surgical emphysema of the neck five weeks after surgery for exostoses of the external auditory canal. Imaging of the temporal bone demonstrated that the surgery had resulted in entry into the temporomandibular joint. A mechanism is proposed for this novel complication.

Adult↗
PubMed1994

Somatic NF2 gene mutations in familial and non-familial vestibular schwannoma.

Vestibular schwannoma occurs both as a sporadic tumour and in the dominantly inherited familial cancer syndrome neurofibromatosis type 2 (NF2). The gene for NF2 has recently been isolated on chromosome 22, and the demonstration of inactivating germline mutations in NF2 patients and NF2 associated tumours suggests that it act as a tumour suppressor. We have investigated 85 sporadic and 2 NF2 associated vestibular schwannomas, and one vagal schwannoma for chromosome 22 allele loss and NF2 gene mutations. A further 7 vestibular schwannomas were investigated for NF2 mutations only. Chromosome 22 allele loss was detected in 34 of 87 vestibular schwannomas and in the vagal nerve schwannoma. Six exons of the NF2 gene were investigated by SSCP analysis in all 95 tumours. Somatic NF2 gene mutations were detected in 13 non-familial vestibular schwannomas and in one of the NF2 vestibular schwannomas. Seven non-familial tumours with an NF2 gene mutation also displayed a chromosome 22 allele loss. Thirteen of the mutations were predicted to produce truncation of the NF2 protein. These results suggest that somatic mutations of the NF2 tumour suppressor gene are a critical step in the pathogenesis of both familial and non-familial vestibular schwannoma and that the mechanism of tumourigenesis complies with a 'two-hit' mutation model.

Adult↗
PubMed1994

Mastoid obliteration using bone pâté.

The technique of mastoid revision and obliteration using bone pâté and a superiorly based temporalis musculo-periosteal flap is described in detail. This method has evolved and been employed in our department over the past 10 years.

Bone Transplantation↗
PubMed1994

Bone pâté obliteration or revision mastoidectomy: a five-symptom comparative study.

A survey of 47 patients who underwent surgical treatment for persistent symptomatic mastoid cavities following mastoidectomy for cholesteatoma, was carried out. There were two groups comprising 26 patients who underwent revision mastoidectomy (14 with meatoplasty); the technique favoured early in the series, and 21 managed by mastoid revision and obliteration with autologous bone pâté and a superiorly based temporalis musculo-periosteal flap. A questionnaire was used to assign a symptom score to each patient's pre and post-operative condition, with a maximum score of 15 and minimum of zero. The pre-operative scores for the two groups were not significantly different, but the patients treated by obliteration with bone pâté had a significantly lower (P = 0.05) postoperative symptom score than those who had their mastoids simply revised. This study suggests that revision mastoidectomy with bone pâté obliteration achieves a more favourable result than revision mastoidectomy alone, and is, we believe, the technique of choice for the patient with a symptomatic mastoid cavity.

Adult↗
PubMed1994

Endolymphatic sac surgery: analysis of 100 operations.

One hundred endolymphatic mastoid shunt operations in 89 patients with classical Menière's disease were analysed. The disease was bilateral in 18 patients (20%). The patients were carefully pre-selected by a comprehensive protocol of audiovestibular and metabolic investigations. All patients had definite electrophysiological evidence of endolymphatic hydrops with an enhanced negative summating potential on transtympanic electrocochleography. The surgical results were analysed both by the original American Academy of Ophthalmology and Otolaryngology Guidelines (AA00, 1972) and the more recent modifications of the American Academy of Otolaryngology, Head and Neck Surgery (AA-HNS, 1985). Control of the vertigo was achieved in 81% of the patients overall, in 88% of the patients with unilateral disease and in 63% of the patients with bilateral disease. A significant hearing improvement was obtained in 19% of patients, no change in 55% and hearing became worse in 26%. Tinnitus improved in 38% of patients, was unchanged in 52% and became worse in 10%. Disability was assessed and there was no disability in 44% of the patients post-operatively, some degree of disability in 48% but only 8% were severely disabled and unable to sustain gainful employment.

Disability Evaluation↗
PubMed1994

Audiological findings in glomus tumours.

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.

Adult↗
PubMed1994

Reduction in junior doctors' hours in an otolaryngology unit: effects on the 'out of hours' working patterns of all grades.

This study aimed to assess the effects of recent controls on juniors' duty hours (the 'New Deal') on the work performed by all grades of ENT medical staff 'out of hours'. For 100 days in 1993 the out of hours duties of all grades of doctor in the Otolaryngology Unit were monitored using daily logs. Three patterns of cover were run in parallel and subjected to comparison: Light: Senior House Officer (SHO)--Consultant (CON); Traditional: SHO-Intermediate (Registrar or Senior Registrar)--Consultant; Cross-cover--Pre-Registration House Officer (PRHO)--Intermediate-Consultant. The SHO 'out of hours' daily workload did not differ significantly between the traditional and light systems (median hours: 5.6 versus 5.0). There was an increase in working hours for the intermediate (registrar or senior registrar) grade of 84 per cent when the cross-cover system was in operation compared with the traditional system (median hours: 5.0 versus 2.8; p < 0.0001--Mann-Whitney U test). Consultant working hours increased by an average of 132 per cent as a result of removal of the intermediate tier (median hours: 1.7 versus 0.80; p < 0.0001). Reduction in on-call hours of junior staff resulted in a need for cross-cover and also in the frequent removal of an intermediate tier of staff. This has been shown to have a considerable effect on working patterns for intermediate and senior grades in an ENT unit of average size. Further reductions would be expected to have major effects on the working patterns of the consultant grade and considerably dilute the emergency experience of trainees.

Consultants↗
PubMed1993

Molecular genetic analysis of the mechanism of tumorigenesis in acoustic neuroma.

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 the NF2 gene; (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.

Adult↗
PubMed1993

Clinical correlates of acoustic neuroma morphology.

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 neurilemmal-neurologlial 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.

Cranial Nerve Neoplasms↗
PubMed1993

Hearing loss fluctuating with blood sugar levels in Ménière's disease.

An unusual case of a patient with bilateral Ménière's disease is described whose disease presented in the second ear as a sensorineural hearing loss which fluctuated with the patient's level of blood glucose. The literature concerning the role of abnormal glucose metabolism in Ménière's disease is reviewed and the investigation and management of this patient's condition is discussed.

Adult↗
PubMed1993

Parapharyngeal space tumour presenting as recurrent uvular oedema.

Neoplasms of the parapharyngeal space are uncommon and usually present as an intra-oral or neck mass. They often elude early diagnosis due to their deep-seated nature. Here we report a case presenting with recurrent oedema of the uvula. The pathophysiology of this previously unreported mode of presentation is discussed.

Adult↗
PubMed1993

Unusual cerebello-pontine angle 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.

Adolescent↗
PubMed1993

Wound closure after acoustic neuroma surgery.

Cerebrospinal fluid leakage from the wound or middle ear cavity remains a common cause of morbidity after acoustic neuroma surgery, regardless of the operative route employed. An incidence of around 15% is reported in most large series. The authors describe a method of wound closure which is applicable to both translabyrinthine and retrosigmoid tumour excision. Adoption of this technique in 188 consecutive patients has reduced the incidence of this complication in our unit from 13% to 1.6%.

Cerebrospinal Fluid Otorrhea↗
PubMed1992

Speech in noise: a practical test procedure.

A simple and effective speech in noise test is described with clinical findings for patients with normal hearing, cochlear and retrocochlear pathologies and auditory dysacusis. The test utilizes material readily available in Audiology and ENT Departments. It was possible to obtain useful diagnostic information in patients who complain of hearing loss, but who demonstrate normal audiometric thresholds and normal speech in quiet discrimination.

Adolescent↗
PubMed1992

What is the effect of translabyrinthine acoustic schwannoma removal upon tinnitus?

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 be severe 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.

Humans↗