Biomedical subjects
M Hawke
Publications and source records attributed to M Hawke.
The incidence and distribution of cupular deposits in the labyrinth.
Findings of large basophilic staining deposits on the cupula of the posterior semicircular canal ampulla have been used in part to explain the clinical phenomenon of benign positional vertigo (BPV). Although it is generally agreed that cupulolithiasis may involve other canal ampullae, the precise nature, distribution, and origin of these deposits remains unclear. In order to provide a better understanding of this finding, a series of 566 temporal bone specimens from the Ear Pathology Research Laboratory at the University of Toronto were reviewed. The results from this survey and speculations concerning the nature and formation of these deposits are discussed.
A new type of nasal packing for use in endoscopic sinus surgery.
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Swirls, wrinkles and the whole ball of wax (the source of keratin in cerumen).
Recent work carried out at the Ear Pathology Research Laboratory has demonstrated that cerumen plugs consist of a large amount of keratin debris. In this study the site of origin of this keratin was investigated. This was done by histologically examining these cerumen plugs without disturbing the natural relationship between the plug and the surrounding epithelium. We have clearly demonstrated that a cerumen plug consists of keratin arising from the migratory epithelium of the deep external auditory canal and epithelium of the superficial external auditory canal.
Presbycusis: correlations of clinical audiology with morphological changes in the cochlea and the ventral cochlear nucleus.
Five cases of presbycusis are presented. Analysis included audiological tests, cochlear hair cell and ganglion cell counts, assessment of degree of strial atrophy, and ventral cochlear nucleus neuron counts. One case showed a reduction in cochlear nucleus neuron counts without significant cochlear changes, indicating that this pattern of pathological changes is a possible cause of high tone sensorineural deafness.
High-resolution computed tomography of an aberrant internal carotid artery.
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Nasal polyps, bronchial asthma and aspirin sensitivity.
The ASA triad comprises bronchial asthma, acetylsalicylic acid (ASA) sensitivity and nasal polyps. It presents as chronic rhinitis followed by bronchial asthma and ASA sensitivity, and later nasal polyps. The pathogenesis of the ASA triad may involve interrelationships between disease in the upper and lower airway and hypersensitivity to cyclo-oxygenase inhibiting medications. Treatment of the nasal polyps has been shown to improve the patients' asthma.
Granular myringitis: a review.
Granular myringitis is the result of a localized chronic inflammation of the lateral surface of the tympanic membrane which is characterized by the development and persistence of granulation tissue over the involved area. The onset of the disease is insidious, and the symptoms, which are minor, are usually confined to chronic otorrhea and mild discomfort in the involved ear. Granular myringitis is a disease which is poorly understood and has received relatively little attention in the literature. The clinical features of this disease are outlined, the pathologic changes in the tympanic membrane illustrated, the literature reviewed and a strategy for treatment presented.
Exostosis of the external auditory canal: an interesting histopathological finding.
Perforation of the tympanic membrane is a frequent complication of surgery for exostoses of the external auditory canal. We report an unusual histopathological finding in a temporal bone containing external canal exostoses which suggests that some of these perforations may be unavoidable.
Sudden hearing loss due to AIDS-related cryptococcal meningitis--a temporal bone study.
We have presented the clinical history and temporal bone findings in a patient who manifested sudden hearing loss, and who subsequently was found to have cryptococcal meningitis associated with AIDS. The histopathologic findings are similar to earlier reports in patients without AIDS. Because cryptococcal infection is so much more common in AIDS patients than in the general population, it must be considered a causative factor when presented with an AIDS patient with progressive or sudden hearing loss. This offers the patient a chance for timely and effective treatment.
Surgical anatomy of the lateral nasal wall.
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The treatment of Menière's disease: Torok revisited.
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The embryonic development of the lateral nasal wall from 8 to 24 weeks.
This histological study of 20 fetal heads aged between 8 and 24 weeks of gestation demonstrates and describes the embryonic development of the lateral wall of the nose. The three turbinates (inferior, middle, and superior) arise as soft-tissue swellings (preturbinates) by 8 weeks' gestation. A cartilage capsule surrounds the nose at 8 weeks and by 9 weeks, medially directed flanges of cartilage have invaded all three preturbinates. The uncinate process arises from the medial surface of the lateral cartilaginous capsule and is first identifiable by 10 weeks. An "air space" progressively develops from 11 to 12 weeks lateral to the cartilaginous uncinate process and from this space, the embryonic channel to the maxillary sinus develops. The embryonic woven bone of the maxilla can be identified from 9 to 10 weeks and enlarges both absolutely and relatively to the nasal cavity, so that by 13 to 14 weeks, this expanding bone forms the lateral wall of the inferior meatus as the cartilaginous nasal capsule regresses.
Radiological features of glomus tympanicum and glomus jugulare.
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Sequelae of experimental tympanic and inferior canal wall perforations: the double meaning of epithelial migration.
The term "epithelial migration" has been used to describe both the normal surface movement of the tympanic epithelium and the movement of epithelial basal cells in repair processes. In an attempt to distinguish between these two processes and to determine their role in the repair of a wounded tympanic membrane, 20 guinea pig tympanic membranes were perforated inferiorly and tattooed with ink through an external incision. Sequential histology of whole temporal bones at intervals from the time of injury up to three weeks showed evidence of movement of the superficial layers of epidermis which was effective in the clearance of cellular debris but not in the closure of the perforation. Drum closure was effected more by the accumulation of exudate and epithelial hyperplasia. The migration of the epithelial basal cells was slow when compared to surface movement. It is suggested that tympanic epithelial surface movement is best described by a passive term such as "epithelial displacement" and that the term migration should be restricted to the activities of the living layers of epidermis.
Diagnosis of rhinoliths with rigid endoscopy.
Three cases of rhinolithiasis are presented in which the diagnosis was facilitated by rigid endoscopic nasal examination. Coronal CT scans were used to delineate accurately the size and site of the rhinoliths. Neutron activation analysis was used in their elemental analysis.
The secondary middle turbinate.
During functional endoscopic sinus surgery, the ethmoidal infundibulum and bulla are accessed through the middle meatus. This paper describes a secondary middle turbinate which arises from the lateral wall of the middle meatus, posterosuperior to the infundibulum and points superiorly within the meatus. A secondary middle turbinate was identified bilaterally in 6 out of 400 coronal CT scans of the nasal cavity and paranasal sinuses. The secondary middle turbinate did not obstruct the osteomeatal complex in any of our patients.
Pitfalls in computed tomography of the paranasal sinuses.
The advent of functional endoscopic sinus surgery has created the need for high-quality radiographic images to assess the paranasal sinuses, document the detailed anatomy of the lateral nasal wall and provide an anatomical map allowing safe functional endoscopic sinus surgery. This paper will discuss our experience of 410 paranasal sinus coronal CT scans performed by the technique described by Zinreich prior to consideration of functional endoscopic sinus surgery. The main indications for the scans were acute recurrent sinusitis, abnormal diagnostic nasal endoscopic examination and persistent facial pain. We will consider both the radiological and surgical difficulties that have arisen from the use of this technique and highlight some of the methods to avoid these difficulties. Claustrophobia and limitation of neck movements, particularly in patients over the age of 60, were the most common factors leading to suboptimal scans. Ensuring that the patient was in a symptom-free interval, the differential diagnosis of the opacified paranasal sinus and patients with gross polypoid disease created the most difficulty in interpretation. The anatomical assessment of the frontal recess and the identification of the optic nerve posterolateral to the posterior ethmoidal cell have created the greatest anatomical difficulty.