Kenneth D. Dolan

Preservation of Cochlear Function after Extensive Labyrinthine Destruction

Four ears are presented with extensive destruction of the bony and membranous labyrinth with loss of caloric function but with retention of hearing. Fourteen similar cases described previously in the literature are reviewed. Our cases are unique in that hearing was preserved after surgical removal of the disease in the inner ear itself. We are unaware of any previous well-documented reports showing such extensive destruction of the pars superior portion of the labyrinth with the preservation of hearing. Possible explanations and theoretical implications are discussed.

Computed Tomography of the Hypoplastic Maxillary Sinus

Computed tomography and magnetic resonance imaging may aid definitive diagnosis of the cause of maxillary sinus opacity. To illustrate this concept, CT findings in a patient with maxillary sinus opacity due to sinus hypoplasia will be shown and discussed

Temporal Bone Computed Tomography in the Preoperative Evaluation for Cochlear Implantation

High resolution computed tomography of the temporal bone is performed routinely in the preoperative evaluation for cochlear implantation. A retrospective review was performed to determine the effect of these studies. The clinical significance was determined through consultation with the referring otolaryngologist and review of the operative reports. Twelve examinations were reviewed. Abnormalities were identified in 12 of the 24 ears examined (eight of 12 patients studied). In two patients the CT examination strongly influenced the selection of the ear to be implanted. In four additional cases information felt to be useful in preoperative planning was provided. Useful information related to potential complications with the mechanical insertion of the electrode apparatus. We conclude that temporal bone abnormalities are common in the population undergoing cochlear implantation and that high resolution temporal bone CT is essential in preoperative evaluation. The CT scan should be interpreted with adequate knowledge of the operative procedure to evaluate any possible barriers to the mechanical insertion of the internal components of the system.

Asymmetry of the internal auditory canals without acoustic neuroma.

During the past five years, nine patients with “significant” unilateral enlargement of one internal auditory canal by polytomography were subsequently found to have freely filling canals on contrast posterior fossa myelography. The radiographic appearance of the enlarged canals varied greatly and included all the various configurations usually suggestive of acoustic neuroma. Likewise, the clinical presentation varied greatly from asymptomatic to highly suggestive of cerebellopontine angle tumor. This series underscores the essential nature of posterior fossa studies in the evaluation of potential acoustic neuromas and the variability of the normal architecture of the internal auditory meatus.

Paranasal sinus radiology, Part 4A: Maxillary sinuses.

The maxillary sinus is frequently involved by inflammatory change. It is also the sinus that is most affected by intrinsic or nearby neoplasms. Since neoplasia and inflammatory disease may mimic each other, radiologic examination often becomes the principal means of differentiating them. Principles of radiologic diagnosis, with attention to changes in the various bony margins in maxillary disease processes, form the basis of this article.

Paranasal sinus radiology, Part 3B: Sphenoidal sinus.

Mucoceles involving the sphenoidal sinus are not as common as those affecting the frontal and ethmoidal sinuses. The subtle expansile change produced by a sphenoidal sinus mucocele often requires conventional tomography or computed tomography examination to be detected. Similarly, involvement of surrounding structures by a sphenoidal mucocele may require special study, which this section illustrates. The sphenoidal enlargement and density change produced by fibrous dysplasia may mimic sinus disease. Focal or widespread bone destruction resulting from neoplastic involvement of the sphenoidal sinus requires special examination similar to that used with mucoceles.

Middle Ear Cholesterol Granuloma

Middle ear masses are difficult to differentiate with computed tomography (CT) as the principal diagnostic tool. Occasionally the location or behavior of the lesion may help the differential diagnosis. Clinical evaluation has depended on observation of color through the tympanic membrane, to differentiate vascular (blue) and avascular (white) lesions. Magnetic resonance imaging (MRI) may be of further differential diagnostic use, as illustrated by the following example.

Infratemporal fossa abscess

A 19-year-old man presented with a 3-day history of dull, throbbing pain in his right upper molar region. The patient had been seen by a dentist 2 days prior to admission, when an abscess was found in tooth 3 and treated with a pulpectomy, postoperative ampicillin, and analgesics. No cultures were performed. The patient returned the next day because of increased swelling and pain and underwent an incision and drainage of a right buccal space abscess with placement of a drain. The patient presented the following day with a complaint of progressive pain and swelling of his right upper jaw, trismus, and decreased visual acuity in the right eye. On examination the patient was in moderate distress with swelling over the right side of the hard palate, the right upper buccal vestibule, and the right temporal space. No fluctuance was appreciated and the right buccal space drain was in place without drainage. The patient was afebrile and vital signs were normal. The white blood cell count was 7,700 with a normal differential.

Internal auditory canal enlargement in Paget's disease appearing as bilateral acoustic neuromas.

A 69-year-old man with a past history of bladder cancer was seen for the evaluation of chronic headaches and recent onset of bilateral hearing loss that was worse on the left. Left-sided cluster headaches had been present for years. More recently the headache had been bilateral-frontal in location and did not decrease with medication. The hearing loss was present for 6 months. On testing it was found to be a mixed conductive and sensorineural loss.

Case report 200

This 39-year-old man complained of post-nasal discharge and headache. The nasal discharge was whitish and not seasonal. During the past year he experienced left periorbital pain which radiated to the occipital area, occurring two to three times monthly and resolving spontaneously after several hours. On physical examination the nasal mocous membrane was normal in appearance except for a small ulceration of the septum produced by self manipulation. The remainder of the examination was normal. The patient responded well to a regimen of antihistamines and propylene glycol nasal solution. Views f rom a radiological screening examination of the paranasal sinuses were obtained (Figs. I-3). Other films were also included, but are not reproduced since they did not alter the diagnostic impression. These included a basal sinus view and a lateral thin section tomogram confirming the location of the bony mass within the sphenoid sinus. Also available was a lateral view of the sphenoid sinus area obtained sometime before, showing that the bony mass had not changed in size or appearance.