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Dive into the research topics where John A. Crowther is active.

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Featured researches published by John A. Crowther.


Journal of Laryngology and Otology | 2000

Aberrant internal carotid artery in the middle-ear space.

Marissa Botma; Robin A. Kell; Jo J. Bhattacharya; John A. Crowther

The incidence of an aberrant internal carotid artery in the middle ear is approximately one per cent and most patients are asymptomatic. We present two patients with an aberrant internal carotid artery who presented with pulsatile tinnitus and an intra-tympanic mass. Here we discuss the clinical presentation, relevant radiographic investigations and further management of these patients.


Journal of Laryngology and Otology | 1988

Primary nasal tuberculosis masquerading as a malignant tumour

David W. Sim; John A. Crowther

Primary nasal tuberculosis is rare. We report a case of primary nasal tuberculosis in an elderly lady who presented with symptoms and signs suggestive of a nasal fossa tumour. Histological examination of the lesion revealed the diagnosis. Treatment was with standard anti-tuberculous chemotherapy. The implications of primary nasal tuberculosis are discussed.


Journal of Laryngology and Otology | 1990

Osteochondroma of the tongue

Carl Watson; John A. Crowther; Mary R. Stephen

A case is described of osteochondroma of the tongue and the literature on osteomata, chondromata and osteochondromata of the tongue is reviewed. The tendency for these tumours to arise in the region of the foramen caecum has been noted in previous reports as has the female preponderance. It has been suggested that they arise from remnants of branchial arch cartilage. The variation in the duration and age at presentation of the lesion has not been explained and an alternative theory is suggested.


British Journal of Oral & Maxillofacial Surgery | 2013

Patterns of local recurrence after primary resection of cancers that arise in the sinonasal region and the maxillary alveolus.

Jeremy McMahon; Ling Siew Wong; John A. Crowther; William Taylor; Joseph McManners; J.C. Devine; Craig Wales; Colin MacIver

Local recurrence remains the most important sign of relapse of disease after treatment of advanced cancer of the maxilla and sinonasal region. In this retrospective study we describe patterns of recurrence in a group of patients who had had open resection for cancer of the sinonasal region and posterior maxillary alveolus with curative intent. Casenotes and imaging studies were reviewed to find out the pattern of any relapse, with particular reference to local recurrence. The minimum follow-up period was 12 months. Of 50 patients a total of 16 developed recurrences, 11 of which were local. Of those 11, a total of 8 were in posterior and superior locations (the orbit, the infratemporal and pterygopalatine fossas, the traversing neurovascular canals of the body of the sphenoid to the cavernous sinus, the Gasserian ganglion, and the dura of the middle cranial fossa). Advanced cancer of the midface often equates with disease at the skull base. Treatment, including surgical tactics, should reflect that.


Scottish Medical Journal | 2015

Neurenteric cyst presenting with stridor and dysphagia: case report and literature review

V Visvanathan; John A. Crowther; William R. Taylor

Objective Neurenteric cysts are rare lesions that account for 0.7–1.3% of all spinal cord tumours. We report the first ever case of a neurenteric cyst presenting with stridor and dysphagia. A literature review on the presentation and management of these lesions is also included. Methods A MEDLINE search of articles using the terms ‘neurenteric cyst’, ‘intraspinal cyst’, ‘enterogenous cyst’, ‘intramedullary cyst’ along with diagnosis, presentation and management was performed. Suitable references from these articles were also reviewed. Results All published evidence on neurenteric cysts are either case series or case reports (level IV/V) with the largest case series reporting 23 patients from a single institution. Conclusion Neurenteric cysts are rare spinal cord lesions that usually present with focal neurological signs and managed within neurosurgical units. This is the first reported case of a neurenteric cyst presenting with upper aerodigestive tract symptoms warranting specialist ear, nose and throat input.


PLOS ONE | 2017

Geographic distribution of vestibular schwannomas in West Scotland between 2000-2015

Lisa Caulley; Michael Sawada; Kelsey Hinther; Ya-tung Iris Ko; John A. Crowther; Georgios Kontorinis

BACKGROUND Although the natural history of vestibular schwannomas (VS) has been previously studied, few studies have investigated associated epidemiological factors, primarily because of the lack of large available cohorts. OBJECTIVE The objective of this study was to perform a multi-scale geographical analysis of the period prevalence of VS in West Scotland from 2000 to 2015. METHODS Adults diagnosed with sporadic VS were identified through the National Health Services of West Scotland database and geocoded to the unit postcode. To assess whether the cohort of VS cases could be pooled into a period prevalence measure, the locations of VS cases were analyzed by sex using Cross-L and Difference-K functions. VS period prevalence was examined at two aggregate spatial scales: the postcode district and a coarser scale of NHS Health Boards. The spatial structure of period prevalence within each level of spatial aggregation was measured using univariate global and local Morans I. Bivariate local Morans I was used to examine the between-scale variability in period prevalence from the postcode district level to the NHS Health Boards levels. Prior to spatial autocorrelation analyses, the period prevalence at the postcode district was tested for stratified spatial heterogeneity within the NHS Health Boards using Wangs q-Statistic. RESULTS A total of 512 sporadic VS were identified in a population of over 3.1 million. Between 2000 and 2015, VS period prevalence was highest within the NHS Health Boards of Greater Glasgow and Clyde, Ayrshire and Arran and the Western Isles. However, at the NHS scale, period prevalence exhibited no spatial autocorrelation globally or locally. At the district scale, Highland exhibited the most unusual local spatial autocorrelation. Bivariate local Morans I results indicated general stability of period prevalence across the postcode district to Health Boards scales. However, locally, some postcode districts in Greater Glasgow and Clyde, Ayrshire and Arran exhibited unusually low district to zone spatial autocorrelation in period prevalence, as did the southern parts of the Western Isles. Some unusually high period prevalence values between the postcode district to Health Board scale were found in Tayside, Forth Valley and Dumfries and Galloway. CONCLUSION Geographic variability in VS in West Scotland was identified in this patient population, showing that there are areas, even remote, with unusually high or low period prevalence. This can be partially attributed to links between primary and tertiary care. Potential genetic or environmental risk factors that may contribute to geographic variation in this disease within Scotland are also a possibility but require further investigation.


Otology & Neurotology | 2017

Delayed Vestibular Schwannoma Regrowth Following Shrinkage After Stereotactic Radiosurgery: Implication for Life-Long Surveillance

Emma Stapleton; John A. Crowther; Richard Locke; Georgios Kontorinis

OBJECTIVE To enhance understanding of the behavior of vestibular schwannomas (VS) after stereotactic radiosurgery (SRS), including the potential for late tumor regrowth, and the need for lifelong radiological and clinical surveillance. PATIENTS From a total of 540 patients with VS and out of 95 patients receiving SRS for their growing VS, the cases of two women patients aged 58 and 59 years with medium sized, growing VS are presented. INTERVENTION Both patients were treated with SRS. Following treatment, both patients had close clinical follow-up and serial magnetic resonance imaging (MRI). MAIN OUTCOME MEASURES Post-SRS clinical assessment and serial MRI to determine VS size and respond to treatment. RESULTS Close clinical follow-up after SRS identified no change in symptoms in one patient; the other developed ipsilateral facial nerve twitching without weakness. Serial MRI identified that in both patients, VS that had initially decreased in size following SRS, exhibited significant late regrowth after a 3-year period, reaching the pretreatment size. CONCLUSIONS This is the first report of late vestibular schwannoma regrowth following a period of significant shrinkage after SRS. Potential reason may be the presence of living cells within the tumor; the possibility of malignant transformation should also be taken into account. Following SRS, patients with VS warrant lifelong radiological and clinical surveillance, even following good response, as there seems to be a small chance of initial regression followed by further growth. Microsurgery for tumor removal and histological diagnosis is indicated in such cases.


British Journal of Oral & Maxillofacial Surgery | 2015

Anterolateral corridor approach to the infratemporal fossa and central skull base in maxillectomy: rationale and technical aspects

Jeremy McMahon; John A. Crowther; William Taylor; Ling Siew Wong; Tom Paterson; J.C. Devine; Craig Wales; Colin MacIver

We describe the technical aspects and report our clinical experience of a surgical approach to the infratemporal fossa that aims to reduce local recurrence after operations for cancer of the posterior maxilla. We tested the technique by operating on 3 cadavers and then used the approach in 16 patients who had posterolateral maxillectomy for disease that arose on the maxillary alveolus or junction of the hard and soft palate (maxillary group), and in 19 who had resection of the masticatory compartment and central skull base for advanced sinonasal cancer (sinonasal group). Early proximal ligation of the maxillary artery was achieved in all but one of the 35 patients. Access to the infratemporal fossa enabled division of the pterygoid muscles and pterygoid processes under direct vision in all cases. No patient in the maxillary group had local recurrence at median follow up of 36 months. Four patients (21%) in the sinonasal group had local recurrence at median follow up of 27 months. Secondary haemorrhage from the cavernous segment of the internal carotid artery resulted in the only perioperative death. The anterolateral corridor approach enables controlled resection of tumours that extend into the masticatory compartment.


Otology & Neurotology | 2018

Spontaneous Vestibular Schwannoma Regression: A Case-Control Study

Theofano Tikka; Constantina Yiannakis; Emma Stapleton; Richard Locke; John A. Crowther; W. Taylor; Georgios Kontorinis


Otology & Neurotology | 2018

Audiological Outcomes in Growing Vestibular Schwannomas Managed Either Conservatively, or With Stereotactic Radiosurgery

Thomas Daniel Milner; Richard Locke; Georgios Kontorinis; John A. Crowther

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Richard Locke

NHS Greater Glasgow and Clyde

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Georgios Kontorinis

NHS Greater Glasgow and Clyde

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William Taylor

Southern General Hospital

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Georgios Kontorinis

NHS Greater Glasgow and Clyde

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Colin MacIver

Southern General Hospital

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Craig Wales

Southern General Hospital

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J.C. Devine

Southern General Hospital

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Jeremy McMahon

Southern General Hospital

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Ling Siew Wong

Glasgow Dental Hospital and School

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