Biomedical subjects

A P Bath

Publications and source records attributed to A P Bath.

At least 19 recordsLinked to original sources

PubMed2000

Experience from a multidisciplinary "dizzy" clinic.

OBJECTIVE: To describe the experience of a combined otolaryngology and neurology multidisciplinary clinic in the evaluation, investigation, and management of patients with dizziness. STUDY DESIGN: Prospective clinical study. SETTING: Patients were seen in a tertiary referral, multidisciplinary clinic at The Toronto Hospital, University of Toronto, Ontario, Canada. INTERVENTION: A thorough history, formal otoneurologic examination, and appropriate laboratory investigations were performed. After their assessment, the patient's diagnoses were classified as peripheral, central, psychogenic, or undiagnosed and were then subdivided into specific clinical diagnoses. RESULTS: The first 812 consecutive patients seen in the multidisciplinary clinic from January 1, 1993 to December 31, 1998 are reported. Five hundred twenty-five (64.7%) patients were found to have a peripheral vestibular cause for their dizziness, 66 (8.1%) had a central cause, 108 (13.3%) had a diagnosis unknown, and 73 (9.0%) were thought to be psychogenic. In 40 (4.9%) patients, a peripheral and central cause were found. More than one type of peripheral disorder was noted in 17.9% of patients with a peripheral vestibular cause for their dizziness, and 12.3% of patients with a central cause for their dizziness had more than one specific type of central nervous system disorder. CONCLUSIONS: Most patients that were seen in a multidisciplinary clinic had a peripheral vestibular disorder. Central causes of dizziness were relatively uncommon. Serious diseases such as tumor, multiple sclerosis, and encephalitis were rare and unlikely to present with dizziness only. It is important to realize that a patient may have more than one type of disorder accounting for the symptoms, which may represent a spectrum of disease affecting the inner ear.

Adolescent↗

PubMed2000

The role of conservative management of vestibular schwannomas.

Although microsurgery is generally regarded as the conventional treatment of choice for most vestibular schwannomas, there remains a group of patients in whom a conservative management approach may be a desirable alternative. The aim of this study was to determine the natural history and outcome following the conservative management of 72 patients with unilateral vestibular schwannomas. The reasons for conservative management included poor general health, age, patient preference, small tumour size, minimal or no symptoms, and tumour in the only/better hearing ear. The mean duration of follow-up was 39.8 months (range 12-194 months). All patients underwent serial magnetic resonance imaging (MRI) for assessment of tumour growth. Patients were deemed to have failed conservative management if there was evidence of continuous or rapid radiological tumour growth and/or increasing symptoms or signs. The mean tumour growth rate, according to the 1995 guidelines of the American Academy of Otolaryngology/Head and Neck Surgery, was 1.16 mm/year (range: 0.75 9.65 mm/year). Approximately 83% of tumours grew at < 2 mm/year. Significant tumour growth was seen in 36.4%, no or insignificant growth in 50%, and negative growth in 13.6% of tumours. The growth rate of CPA tumours (1.4 mm/year) was significantly greater than that of IAC tumours (0.2 mm/year) (P = 0.001). Failure of conservative management, in which active treatment was required, occurred in 15.3%. The outcome of these patients appeared to be as favourable to a comparable group who underwent primary treatment, without a period of conservative management. The mean growth rate of tumours in patients who failed conservative management (4.2 mm/year) was significantly greater than that in patients who did not fail (0.5 mm/year) (P < 0.01). No factors predictive of tumour growth or failure of conservative management were identified. Deterioration of mean pure tone average (0.5, 1, 2, 3 kHz) and speech discrimination scores occurred regardless of whether radiological tumour growth was demonstrated or not. This study suggests that in a select number of cases of vestibular schwannoma, a conservative management approach may be appropriate. Regular follow-up with serial MRI is mandatory. Deterioration of auditory function occurs even in the absence of tumour growth.

Case-Control Studies↗

PubMed2000

Consequences to hearing during the conservative management of vestibular schwannomas.

OBJECTIVE: To estimate the risk of loss of serviceable hearing during the conservative management of vestibular schwannomas. STUDY DESIGN: Retrospective case review. METHODS: Twenty-five patients with a radiological diagnosis of unilateral vestibular schwannoma were managed conservatively for a mean duration of 43.8 months (range, 12-194 mo). The pure-tone average (PTA) (0.5, 1, 2, and 3 kHz) and speech discrimination scores (SDS) were measured at regular intervals throughout the entire duration of follow-up. Serviceable hearing was defined using two criteria: 70% SDS/30 dB PTA (the 70/30 rule) and 50% SDS/50 dB PTA (the 50/50 rule). The size and growth rate of tumors were determined according to the American Academy of Otolaryngology-Head and Neck Surgery guidelines (1995). Intervention was recommended if there was evidence of continuous or rapid radiological tumor growth, and/or increasing symptoms or signs suggestive of tumor growth. RESULTS: The risk of loss of serviceable hearing for the total group was 43% using the 70/30 rule and 42% using the 50/50 rule. Tumor growth was considered significant (> 1 mm) in 8 tumors (32%) and nonsignificant in 17 (68%). The risk of loss of serviceable hearing for the tumor-growth group was 67% using the 70/30 rule and 80% using the 50/50 rule. In contrast, the risk of loss of serviceable hearing for the no tumor-growth group was 25% using the 70/30 rule and 14% using the 50/50 rule. No audiological factors predictive of tumor growth were identified. CONCLUSIONS: There is a significant risk of loss of serviceable hearing during the conservative management of vestibular schwannomas. This risk appears to be greater in tumors that demonstrate significant growth.

Adult↗

PubMed1999

Presumed reduction of vestibular function in unilateral Menière's disease with aminoglycoside eardrops.

We report the first case in the world literature of deliberate ablation of vestibular function in unilateral Menière's disease with aminoglycoside eardrops (Garasone). These findings give conclusive proof that Garasone eardrops, and by implication, all topical aminoglycoside ear drops can be vestibulotoxic in the presence of a tympanic membrane defect. The lower concentration of gentamicin in Garasone, in comparison to the standard intratympanic preparations for chemical ablation of vestibular function, may also offer a reduction in the potential risk of cochleotoxocity.

Anti-Bacterial Agents↗

PubMed1999

Paediatric subglottic stenosis.

Most reports on paediatric subglottic stenosis have arisen from tertiary referral centres. At the Sheffield Children's Hospital, referrals come from the surrounding region such that almost all paediatric airway problems from this area are seen. This allows an opportunity to look at the overall picture of this condition. A retrospective study was performed to identify all children with subglottic stenosis requiring a tracheostomy since 1979 and to examine the management and eventual outcome in relation to the severity of their stenosis. Forty-two children were identified. There have been four mortalities, two of which have been tube related. Twenty-two laryngotracheoplasty procedures have been performed in 17 patients. Successful decannulation has been achieved in 82%. In the majority of children with more minor stenoses conservative management has lead to successful decannulation. However, with increasingly severe stenosis the necessity of undergoing a laryngotracheoplasty procedure to provide an adequate airway becomes more likely.

Child↗

PubMed1999

Effect of conductive hearing loss on the vestibulo-collic reflex.

The vestibulo-collic reflex represents a promising test for evaluating the integrity of otolith function. We have investigated the threshold of this response in a group of normal subjects, and the effect of a conductive hearing loss. A positive response was recorded in 31 of 32 normal subjects. The threshold of the vestibulo-collic reflex varied from 80 to 97 dBHL in these subjects with a 95% response rate at a threshold at 96 dBHL. A total of 23 ears with a conductive hearing loss in 17 patients were also investigated. The average conductive hearing loss (at 0.5, 1, 2 and 4 kHz) ranged from 8.75 to 40 dBHL (average 24.46 dBHL). A positive response was recorded in only two ears. Therefore, the vestibulo-collic reflex has a high stimulus threshold which is dependant on reliable transmission of the click stimulus to the inner ear thus limiting is clinical use.

Adult↗

PubMed1999

Long-term results of posterior semicircular canal occlusion for intractable benign paroxysmal positional vertigo.

Benign paroxysmal positional vertigo (BPPV) is a common condition which is usually managed conservatively, surgical intervention being recommended only for those small number of patients in whom it becomes persistent and incapacitating. The results of surgery in 13 patients who underwent posterior semicircular canal occlusion for intractable (> 12 months duration) and incapacitating BPPV are presented with special emphasis on their long-term follow-up. The mean follow-up was 66 months (range, 29-119 months). All patients reported complete and immediate resolution of their positional vertigo, which has been maintained in the long term. Most patients, however, reported some postoperative transient unsteadiness which lasted up to 4 weeks. All patients developed a transient mild conductive hearing loss secondary to a middle ear collection, which usually resolved within 4 weeks. Five patients developed a transient mild high frequency sensorineural hearing loss which resolved in all cases within 6 months. There were no reports of sensorineural hearing loss nor tinnitus in the long term. All patients believed that the operation was beneficial and would undergo it again. Our findings indicate that posterior semicircular canal occlusion is an effective and safe operation in the long term and is the procedure of choice for intractable and incapacitating BPPV rather than singular neurectomy.

Adult↗

PubMed1999

Ototoxicity of topical gentamicin preparations.

OBJECTIVE: To document that commercially available topical gentamicin-containing eardrops carry a risk of ototoxicity if they reach the middle ear through a tympanic membrane defect. STUDY DESIGN: Clinical study, retrospective case-note review. SETTING: Department of Otolaryngology, The Toronto Hospital, University of Toronto. PATIENTS: Sixteen patients were identified with well-documented histories, physical findings and laboratory investigations consistent with topical gentamicin-induced ototoxicity. One patient with incapacitating unilateral Meniere's disease underwent successful intentional vestibular ablation using topical gentamicin/steroid drops. RESULTS: In all cases of inadvertent ototoxicity, patients had used the drops for longer than 7 days (average 20.7 d) prior to symptoms developing. All patients developed vestibulotoxicity that was confirmed on ENG testing. Only 1 patient had a noticeable worsening of cochlear reserve. Deliberate and successful therapeutic ablation of vestibular function in a patient with unilateral Meniere's disease confirms the vestibulotoxic nature of commercially available topical gentamicin preparations. CONCLUSIONS: Physicians should consider the potential for ototoxicity if gentamicin-containing eardrops (and by extrapolation all topical aminoglycoside drops) are used for longer than 7 days in patients with a tympanic membrane defect. These preparations should not be used in the presence of healthy middle ear mucosa and should be discontinued shortly after the discharge has stopped. It is important to recognize that toxicity is primarily vestibular rather than cochlear.

Administration, Topical↗

PubMed1998

Effective anaesthesia for transtympanic electrocochleography.

The objective of this study was to quantify the anaesthetic effect of EMLA cream during transtympanic electrocochleography (TTECochG) and thereby to determine if the application of EMLA should be recommended in routine practice of electrocochleography (ECochG). ECochG provides useful information in patients with inner ear fluid disorders. A major concern regarding transtympanic positioning of the electrode in ECochG is patient discomfort. Previous work has suggested that EMLA cream may make this technique more tolerable to patients. A prospective randomized study was performed evaluating the discomfort associated with unilateral TTECochG in a group where EMLA cream was used to anaesthesize the tympanic membrane (n = 24), and in a group where no anaesthesia was used (n = 22). A statistically significant difference was evident between the discomfort ratings of the groups (P < 0.0001, Mann-Whitney U test), the discomfort being greater in the no anaesthesia group. EMLA cream has thus been shown to alleviate the level of discomfort associated with TTECochG and so to be an acceptable modification of this technique.

Adult↗

PubMed1998

Tonsillar metastasis from malignant pulmonary carcinoid tumour.

Tumour metastases to the tonsil are rare and are usually due to spread from malignant melanoma and carcinomas of the breast, lung, kidney or stomach. We describe the clinical and histological findings of a tonsillar metastasis from a malignant pulmonary carcinoid tumour, an occurrence not previously reported.

Carcinoid Tumor↗

PubMed1998

Malignant otitis externa with optic neuritis.

Malignant otitis externa is a serious condition that presents difficulties in treatment, and also in monitoring its progress. A case of malignant otitis externa with optic neuritis is presented that remained refractory to standard treatment but was cured by adjuvant hyperbaric oxygen therapy. This is the only reported case that has survived this disease with optic neuritis. The usefulness of imaging techniques in this condition is discussed, as well as the ESR, in evaluating the effectiveness of treatment.

Blood Sedimentation↗

PubMed1998

The vestibulo-collic reflex.

Until now there has no been no simple, reliable clinical test that assesses the function of the otolith organs. However, recent work has suggested the occurrence of an easily identifiable electromyographic (EMG) waveform in isometrically contracting sternomastoid muscles in response to loud clicks. This is thought to represent an otolith evoked disynaptic reflex. Equipment routinely used for evoked response audiometry (ERA) has been adapted to investigate this response. A short latency (8 ms) positive-negative EMG waveform has been recorded in 31 of 32 normal subjects. The latency of the positive peak (P1) is 11.7 ms (SD = 0.89), and the negative peak (N1) is 20.5 ms (SD = 1.89). It is predominantly ipsilateral, although a contralateral response was present in 35.5%. The response has also been recorded in three patients with a severe unilateral sensorineural hearing loss and normal caloric responses, and in a patient undergoing cochlear implantation for profound bilateral sensorineural hearing loss. Further work is required to delineate the value of this technique in investigating vestibular lesions.

Adult↗

PubMed1997

Management of upper airway obstruction in Pierre Robin sequence.

Pierre Robin sequence (PRS) presents in the neonatal period with upper airway obstruction and feeding difficulties. Infants with pronounced micrognathia may fail to thrive because of chronic airway obstruction, or experience severe respiratory distress. This is potentially fatal and surgical intervention in these cases is necessary. We present our series of cases with severe PRS requiring surgical relief of their airway obstruction, and the reasons for preferring tracheostomy over glossopexy.

Airway Obstruction↗

PubMed1994

Survey of analgesia regimens in burns centres in the UK.

A survey of the analgesia regimens used in burns units throughout the UK was performed. Continuous intravenous opiate infusions remain the mainstay for providing pain relief in patients in severe pain as a result of burn injuries. Other methods include: patient-controlled analgesia in appropriate patients, bolus doses of opiates combined with Entonox for control of peaks of pain and a wide variety of oral analgesics for less painful burn injuries.

Analgesia↗

PubMed1994

Metastatic adenocarcinoma of the temporal bone.

Metastatic carcinoma involving the temporal bone is extremely rare. A case is reported with an unusual presentation--recurrent episodes of acute mastoiditis. Mastoid exploration and biopsy established the diagnosis. We believe this to be the first reported case to present in this manner.

Adenocarcinoma, Mucinous↗

PubMed1994

Technique of tracheo-oesophageal puncture under local anaesthesia.

Various techniques for performing a secondary tracheo-oesophageal puncture to enable insertion of a speech prosthesis in laryngectomized patients have been described. We describe a modification that allows a safe secondary tracheo-oesophageal puncture under local anaesthesia using standard equipment available in an ENT department.

Anesthesia, Local↗

PubMed1993

Munchausen syndrome by proxy: otolaryngologists beware!

Munchausen syndrome by proxy (MSBP) is a rare condition in which a parent or guardian fabricates an illness in a child either by inducing physical signs or prevaricating. A case presenting as recurrent episodes of infant apnoea is reported. A high index of suspicion is required for the diagnosis and, therefore, the otolaryngologist must be familiar with the condition if the life of the infant is to be protected and potentially harmful unnecessary investigations are to be avoided.

Apnea↗

PubMed1993

Paediatric cochlear implantation: how reliable is computed tomography in assessing cochlear patency?

This study investigates the accuracy of pre-operative high resolution computed tomographic (CT) scans in predicting the patency of the cochlea in children undergoing cochlear implantation. The first 26 children on the Nottingham Paediatric Cochlear Implant Programme were reviewed. CT scans were performed utilizing 1 mm contiguous sections and these were then assessed by a neuroradiologist. In patients who had normal inner ears on CT a high degree of accuracy in predicting a patent cochlear was achieved (87%). However, in 15% of cases the degree of ossification was significantly under-estimated causing major difficulties at the time of surgery. Although high resolution CT offers great clarity and fine detail, it has its limitations. Further information may be provided by magnetic resonance imaging.

Calcinosis↗