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Biomedical subjects

I R Swan

Publications and source records attributed to I R Swan.

At least 19 recordsLinked to original sources
PubMed2000

Hearing impairment in 18q deletion syndrome.

The 18q-syndrome is associated with hearing impairment in 50-80 per cent of cases. The hearing loss may be sensorineural or conductive. A high proportion of cases are associated with narrow or stenosed external auditory canals. This may be a useful clinical pointer to the syndrome. Two cases with impaired hearing are presented in this paper including one case with complex external ear and middle ear malformations. The clinical and audiological features in each case are described.

Adolescent↗
PubMed1995

The value of routine in-the-ear measurement of hearing aid gain.

When selecting the frequency response of a hearing aid, a target is usually selected using a predictive formula from the international literature. Nowadays real ear measurements can readily be carried out to ensure that the real ear gain closely matches the prescribed target. Such measurements are usually only carried out on a subset of patients fitted in the UK, though it has been suggested that they should be carried out on all hearing aid prescriptions. Real ear insertion gains were measured on 319 first-time National Health Service (NHS) hearing aid issues. A total of 181 (57%) failed to come within 10 dB of the target gain at one or more frequencies between 0.25 and 3 kHz. Though there were audiometric differences between those who achieved satisfactory gain and those who did not, there was too much overlap between groups to make any audiometric index or combination of indices of value in predicting the likelihood of failure to achieve target gain. Sixty-eight patients with inadequate real ear gain were invited to attend for alterations to their hearing aid prescription. Twelve (18%) were fitted with a high frequency aid, while the rest were managed by alterations to their NHS aid or to the earmould and tubing. After appropriate changes, 58 (85%) achieved a satisfactory gain. The routine use of real ear insertion gains in all hearing aid fittings would result in many patients having a more accurately fitted hearing aid. As the majority of prescriptions could be adequately improved using NHS hearing aids, the effects on the hearing aid budget would be relatively small.

Adult↗
PubMed1994

A prospective evaluation of direct referral to audiology departments for hearing aids.

It has been suggested that a proportion of individuals with a hearing impairment can be fitted with a hearing aid without being otolaryngologically assessed. Such assessments are deemed advisable: (a) to identify otological pathology that might require management and (b) because surgery can be a viable alternative in those with a conductive impairment. The aim of this study was to prospectively study individuals referred to an Otolaryngology Department in a teaching hospital to assess how technicians, at a direct referral clinic for the provision of a hearing aid, could screen to identify those meriting an otolaryngological opinion. Two hundred and forty-eight patients were evaluated by technicians using strict audiometric and tympanometric criteria. One hundred and twenty-five patients (50 per cent) failed these criteria and were referred to an otologist. The remaining 123 (50 per cent) were managed by technicians but were subsequently reviewed for the purpose of this study by an otologist and their management assessed. In only two patients (one per cent) was it thought that the initial management would have been different if seen by an otologist. Alternative criteria for deciding suitability for management by technicians were applied. The inclusion of tympanometry was essential to avoid missing middle ear pathology.

Acoustic Impedance Tests↗
PubMed1993

The absence of Harvey ras mutations during development and progression of squamous cell carcinomas of the head and neck.

We have examined the incidence of Harvey ras mutations in human squamous cell carcinomas (SCC) of the upper aerodigestive tract using the polymerase chain reaction (PCR) followed by direct sequencing. No mutations were detected at codons 12, 13, 59 or 61 of this gene in any of six papillomas, five erythroplakias, 56 squamous cell carcinomas, and 16 SCC cell lines. Some of the SCC were lymph node metastases (three) or tumours which had recurred following radiotherapy (seven). We conclude that Harvey ras mutations are not a common event in the pathogenesis or recurrence of SCCs from Caucasian subjects, in contrast to the situation with Indian populations (Saranath et al., 1991).

Base Sequence↗
PubMed1992

Endoscopic photographic comparison of drug delivery by ear-drops and by aerosol spray.

The Otomize (Stafford-Miller Ltd) aerosol spray is a new device for delivering topical ear medication in otitis externa. Both the manufacturers and a recent study have claimed that the spray produces better coverage of the external ear canal than do traditional ear-drops. We performed an endoscopic photographic comparison study to investigate this claim. The are of tympanic membrane and ear canal covered with medication was greater in those ears treated with the aerosol (P less than 0.001, paired t-test). The ability of the aerosol to deliver drug to the level of the tympanic membrane suggests a possible role for this device in the treatment of chronic otitis media. The technique of endoscopic photography provides an objective and reproducible means of investigating drug delivery systems for otological conditions.

Administration, Topical↗
PubMed1992

Chronic otitis media: a new extra-articular manifestation in ankylosing spondylitis?

Following a study reporting a fourfold increase in the occurrence of chronic otitis media in patients with ankylosing spondylitis, this prospective study examines this association with respect to severity, duration of disease, and acute phase in ankylosing spondylitis. Forty two consecutive patients with classical ankylosing spondylitis seen at the rheumatology clinic of a teaching hospital where the features of ankylosing spondylitis were recorded had an otological examination by an otolaryngologist. The occurrence of chronic otitis media (all categories) was 12/42 (29%). The acute phase serum markers (C reactive protein and IgG) were increased in patients with active or inactive chronic otitis media. Extra-articular manifestations were significantly more common in the chronic otitis media group than in those with no history of chronic otitis media. The results of this study suggest that chronic otitis media may be another extra-articular manifestation of ankylosing spondylitis. Alternative explanations, however, include similar aetiological factors for the two conditions or a previously unrecognised increased occurrence of HLA-B27 in patients with chronic otitis media.

Chronic Disease↗
PubMed1991

Clinical and financial audit of diagnostic protocols for lesions of the cerebellopontine angle.

OBJECTIVE: To assess the diagnostic efficiency and costs of protocols used for investigating patients with suspected lesions of the cerebellopontine angle. DESIGN: Prospective evaluation of tests of auditory brain stem responses and acoustic reflex thresholds, electronystagmography, and calorics. Positive test results were confirmed or refuted by high resolution computed tomography with intravenous enhancement. SETTING: Single general otolaryngology clinic in a teaching hospital. PATIENTS: 270 consecutive patients with sensorineural hearing loss requiring investigation to exclude a lesion of the cerebellopontine angle. MAIN OUTCOME MEASURES: Estimated costs of various diagnostic protocols and performance in detecting tumours of the cerebellopontine angle. RESULTS: Protocols including tests of auditory brain stem responses and acoustic reflex thresholds as sifting tests before computed tomography were clinically acceptable and presented considerable savings over the use of computed tomography in all patients (74,000 pounds or 84,000 pounds v 122,000 pounds). The use of electronystagmography and calorics could not be justified on clinical or financial grounds. CONCLUSIONS: Audiological tests of auditory brain stem responses and acoustic reflex thresholds followed by computed tomography constitute the most cost effective protocol for determining suspected lesions of the cerebellopontine angle. IMPLICATIONS: The cost effectiveness of diagnostic protocols should be evaluated throughout the health service.

Caloric Tests↗
PubMed1991

Chronic otitis media and ankylosing spondylitis: an HLA association?

A prospective study was undertaken to investigate an apparent correlation between ankylosing spondylitis (AS) and the incidence of otological conditions. 42 consecutive patients attending the ankylosing spondylitis clinic were examined otoscopically and had audiometric assessment. 19% of the patients (8/42) had active or inactive chronic otitis media. The prevalence of chronic otitis media in this group was significantly greater (P less than 0.01) than a stratified sample of the general population from the Medical Research Council Institute of Hearing Research National Study of Hearing, controlled for age, sex and socio-economic group, where the expected incidence was 5%. A hypothetical explanation for the association is given and the need for HLA studies into chronic otitis media is discussed.

Bone Conduction↗
PubMed1991

The Glasgow Benefit Plot: a new method for reporting benefits from middle ear surgery.

Conventionally, the results of middle ear surgery are reported in terms of postoperative closure of the air-bone gap or the improvement in air-conduction thresholds. While these are relevant in that they assess the technical success of the procedure and the lessening of monaural disability, they do not necessarily assess whether the patient has benefited. This is determined by many factors, not least of which is the hearing in the nonoperated ear. In this paper, we suggest that preoperative and postoperative plots of the air-conduction thresholds in both ears be used as an additional method of presenting the results. First, the proportion of patients that fall into each of three main preoperative impairment groups are identified. This is important, as the potential benefits from surgery are not the same in each group. Thereafter, the percentages of patients that achieve various postoperative hearing categories can be calculated, allowing surgeons to audit their results and make comparisons between series.

Adult↗
PubMed1991

Costs of investigative protocols for cerebellopontine angle lesions in Scotland.

Efficient use of resources demands evaluation of current practices. This paper presents a prospective evaluation of investigative protocols for cerebellopontine angle lesions. Commonly used protocols vary greatly in their clinical effectiveness and in their costs. The use of appropriate protocols would increase the number of tumours correctly diagnosed each year while also limiting the costs of investigation.

Cerebellar Neoplasms↗
PubMed1990

Long-term sequelae of treatment for testicular germ cell tumours.

Seventy-four patients previously treated in our department for germ cell tumour of the testis underwent a series of tests to determine the frequency of long-term therapeutic complications. All had received cisplatin-based chemotherapy as part of their treatment. There was a significant deterioration in renal function throughout the group. Eighteen (24%) had supine blood pressure greater than systolic 140 mmHg or diastolic 90 mmHg after treatment but hypertension did not correlate with renal impairment. Raynaud's phenomenon was common after chemotherapy (26/74) as was persistent sensory neuropathy (23/74). Although 34% had testosterone levels below the normal range, only six patients had a low free testosterone index with one testis still in situ; 18 patients have fathered children after chemotherapy. Approximately half of the patients completed a psychosexual questionnaire and some 30% of them admitted to sexual problems which they attributed to their treatment. Long-term sequelae of cisplatin-based chemotherapy for testicular malignancy are frequent and persistent, and follow-up of these patients should include prospective measurement of changes in blood pressure.

Adolescent↗
PubMed1990

Factors influencing consultation for management of hearing disability.

The aim of this study was to compare individuals referred to an Audiology Clinic (consulters) with hearing-impaired individuals in the population who have never sought advice (non-consulters) in order to identify factors which lead some individuals with hearing problems to seek management while others with apparently similar impairments do not seek advice. Two hundred and sixty nine consulters referred to the Audiology Clinic at Glasgow Royal Infirmary were compared with 289 individuals identified in the MRC National Study of Hearing who had never sought advice as an adult about hearing problems. Age, sex, socio-economic group and better-ear hearing threshold were controlled for in all analyses. Consulters were found to have more asymmetrical hearing than non-consulters. They had greater measured disability and reported more disability when their measured disability and impairment were controlled for. They were also more handicapped when impairment and disability were controlled for.

Adult↗