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Biomedical subjects

B E Hirsch

Publications and source records attributed to B E Hirsch.

At least 55 records · Page 3Linked to original sources
PubMed1994

Excision of petroclival tumors by a total petrosectomy approach.

The surgical removal of intradural petroclival tumors of any size is demanding because of the restricted surgical exposure and relation of the tumor with the brain stem, cranial nerves, and vertebrobasilar artery and branches. When petroclival tumors are large or giant sized and involve multiple areas of the clivus, adequate surgical exposure is difficult to achieve, yet is critical for safe tumor removal. In 17 patients with extensive petroclival tumors, total removal of the petrous bone was performed to gain a wide and shallow surgical exposure. This report details the intraoperative and postoperative complications, cranial nerve status, pre- and postoperative disability scores, and extent of tumor resection in these 17 patients. Deterioration of facial nerve function was the most common new cranial nerve injury following surgery. Three patients suffered major neurologic complications; six other patients suffered significant but temporary neurologic complications. Gross total tumor resection was accomplished in 9 of 17 patients, and most patients (15/17) maintained or improved their disability status. Tumor residual was related to cavernous sinus involvement, vascular encasement, or brainstem pial invasion. Total petrosectomy is an intensive and complex approach with inherent morbidity and thus should be reserved for extensive petroclival tumors that cannot be removed using less complicated approaches.

Adolescent↗
PubMed1993

Simultaneous presentation of malignant external otitis and temporal bone cancer.

Malignant external otitis and squamous cell carcinoma of the external auditory meatus are both characteristically seen in the older population. While some of the signs and symptoms of these two diseases are similar (otalgia, otorrhea, bone destruction on computed tomographic scan), they have rarely been reported in the same patient. We present an unusual case of temporal bone cancer and malignant external otitis presenting concurrently in an elderly, nondiabetic host. Precipitating factors and diagnostic criteria are discussed. This case illustrates the importance of an adequate biopsy specimen in all patients presenting with presumed "classic" malignant external otitis. Consideration must also be given for the existence of malignant external otitis in the presence of carcinoma. Finally, evolution of malignant external otitis in this patient following aural irrigation supports previous suggestions that this disease may be induced iatrogenically.

Aged↗
PubMed1993

Sources of error in use of beta-2 transferrin analysis for diagnosing perilymphatic and cerebral spinal fluid leaks.

Beta-2 transferrin is a protein found in cerebral spinal fluid and inner ear perilymph, but not in blood, nasal, or ear secretions. The clinical use of this test has been previously demonstrated, but sources of test error have not been addressed. The purpose of this study was to evaluate sources of error related to this test in order to improve its clinical use. We reviewed the specimens submitted for beta-2 analysis over the first 12 months of test availability at our institution to identify potential factors leading to test error. Sources of error were categorized into the following groups: sample collection, delivery, and extraction factors; assay factors; physician-related factors; and patient-related factors. The test for beta-2 transferrin is a valuable diagnostic tool for the management of difficult clinical problems, provided the physician is aware of potential factors that can lead to test error and clinical mismanagement.

Bias↗
PubMed1993

Facial nerve near the external auditory meatus in man: computer reconstruction study--preliminary report.

The anatomy of the facial nerve relative to its intratemporal and extratemporal courses varies over time with developmental changes. Otologic and parotid surgery in infants and children demands detailed knowledge of the precise anatomy of the facial nerve with respect to the tympanic ring and external auditory canal. The authors analyzed this area using our three-dimensional (3-D) computer-aided reconstruction and measurement method studying the spatial relations of the facial nerve to the tympanic ring and stylomastoid foramen. Temporal bones from five normal individuals aged 36 gestational weeks, 3 months, 8 months, 4 years, and 17 years were retrieved from the temporal bone collection stored at the Elizabeth McCullough Knowles Otopathology Laboratory in Pittsburgh. Three-dimensional reconstruction of the facial nerve comparing the developmental anatomy across the various age groups provides the surgeon with the technical information necessary to address problems in this area.

Adolescent↗
PubMed1993

Facial nerve function following cerebellopontine angle surgery: prognostic value of electroneurography.

Preoperative counseling of patients, regarding facial nerve function following cerebellopontine angle (CPA) surgery, has remained a difficult task. Facial nerve electroneurography (ENoG) or evoked electromyography can detect subclinical neural degeneration. This test was used in 44 patients undergoing CPA surgery, and facial nerve function was followed postoperatively. A normal preoperative ENoG study appeared to predict an 81 percent and 84 percent chance of good (House grade I-II) early and late postoperative facial function, respectively. An abnormal test is not as reliable. The relation of preoperative ENoG results with tumor size and tumor adherence to the facial nerve is investigated. Electroneurography appears to be a useful preoperative test when counseling patients regarding facial function following CPA surgery.

Adult↗
PubMed1993

Facial nerve function following cerebellopontine angle surgery: prognostic value of intraoperative thresholds.

Intraoperative stimulation of the facial nerve during surgery of the cerebellopontine angle greatly aids the surgeon in identification of the nerve. The preservation of the ability to stimulate the facial nerve, at the brain stem following tumor removal, has been shown to correlate with good postoperative facial outcome. Thresholds of facial nerve stimulation recorded in our series, using constant voltage stimulation, showed statistically significant relevance to facial nerve outcome. When the difference between thresholds before and after tumor removal was 0.2 V or less or when the threshold after tumor removal was less than or equal to 0.2 V, a good postoperative facial outcome could be expected. This paper discusses the relevance of stimulation threshold prior to tumor removal to the size of tumor.

Adult↗
PubMed1993

Beta-2 transferrin assay in clinical management of cerebral spinal fluid and perilymphatic fluid leaks.

Beta-2 transferrin is a protein found in cerebral spinal fluid (CSF) and inner ear perilymph, but not in blood, nasal or ear secretions. The purpose of this paper is to evaluate the clinical usefulness of the current assay for beta-2 transferrin for detecting CSF and perilymphatic leaks. We reviewed the hospital records of the first 88 patients having specimens submitted for beta-2 transferrin analysis at our institution. Both CSF and perilymph leaks were identified. However, confirmation of the absence or presence of beta-2 transferrin was directly used in the clinical management of only 55% of the patients. This was largely secondary to the time delay in test processing and initial lack of physician confidence with the test. However, our review of the clinical outcomes relating to the use of the beta-2 transferrin analysis suggests high sensitivity and specificity for the test. Analysis of beta-2 transferrin appears to be a valuable test for detecting CSF leakage and a promising test for confirming perilymphatic leaks. However, to achieve greater clinical usefulness a rapid clinical assay needs to be developed and further information gained regarding the sensitivity and specificity of the beta-2 transferrin assay for detecting CSF and perilymphatic fluid leakage.

Adult↗
PubMed1993

Translabyrinthine approach to skull base tumors with hearing preservation.

The improvement in surgical techniques and the experience gained in treatment of skull base tumors have stimulated more aggressive management of larger lesions. Patients presenting with limited preoperative deficits have challenged the surgeon to design the surgical approach so as to minimize postoperative morbidity and preserve function. Tumors of the middle fossa and clivus with extension into the posterior fossa are usually approached by a combined subtemporal, transtentorial, transpetrous approach. In patients with preoperative hearing, the surgical exposure is often limited by the labyrinthine portion of the otic capsule. The technique of partial labyrinthectomy, removing the posterior and/or superior semicircular canals, maximizes exposure with preservation of hearing. This report details our experience with the partial labyrinthectomy approach for 14 patients with large skull base lesions. All patients had hearing preserved despite sacrifice of one or two of the semicircular canals. Bone pure-tone averages and speech discrimination scores were maintained near their preoperative levels. The indications, benefits, techniques, and hearing results of this approach are reviewed.

Adult↗
PubMed1993

Treatment of idiopathic sudden sensorineural hearing loss.

A retrospective review was done, examining the charts of 41 patients admitted to The Eye and Ear Hospital of Pittsburgh with a diagnosis of sudden hearing loss (SHL). Treatment consisted of (1) systemic steroids; (2) daily intravenous histamine infusion; and (3) carbogen (95% oxygen and 5% CO2) inhalation. Parameters examined included age, sex, duration of symptoms prior to admission, days hospitalized, side of lesion, vestibular symptoms, tinnitus, blood work, radiography, vestibular function (ENG), and serial audiograms. Fifty-four percent showed improvement in hearing, defined as at least a 10-dB increase at any frequency following therapy. There was no correlation of preexisting signs, symptoms, or findings with hearing recovery. Since the natural history of this process demonstrates spontaneous improvement in approximately two thirds of patients without treatment, we conclude that for the group of patients that we treated, our therapeutic regimen was ineffectual.

Adolescent↗
PubMed1992

Magnetic resonance imaging of the large vestibular aqueduct.

The large vestibular aqueduct syndrome describes an abnormally large endolymphatic duct and sac with associated sensorineural hearing loss. This entity was originally reported in 1978 and has since been identified as a finding in children with progressive hearing loss. The original description of the large vestibular aqueduct employed hypocycloidal polytomography of temporal bone. Subsequent reports studied patients identified with this syndrome using computed tomographic scans. We report magnetic resonance imaging of two patients diagnosed with the large vestibular aqueduct syndrome. The magnetic resonance imaging and computed tomographic scans are compared and the significant findings on magnetic resonance imaging are reviewed. This should assist the otolaryngologist and radiologist with establishing the appropriate diagnosis.

Adult↗
PubMed1992

Single-stage management of cholesteatoma.

Surgical management of chronic otitis media with cholesteatoma can be performed in a single-stage procedure, with revision surgery necessary because of recurrent disease or electively with unsatisfactory hearing results. We retrospectively reviewed 164 cases with cholesteatoma surgically managed from 1980 through 1986. In total there were 11 tympanoplasties, 36 canal wall-up mastoidectomies, 81 canal wall down modified radical mastoidectomies, and 36 radical mastoidectomies. The recidivistic rate for cholesteatoma in patients available for 5-year followup was 11% for tympanoplasties, 19% for canal wall-up mastoidectomies, 5% for canal wall-down modified radical mastoidectomies, and 0% for radical mastoidectomies. Hearing results were best in patients who required tympanoplasty alone, followed by those who underwent canal wall-down procedures. Single-stage management of cholesteatoma with modified radical mastoidectomy (canal wall-down) required fewer revisions for recidivistic cholesteatoma and achieved better hearing results than canal wall-up procedures. We conclude, therefore, that staging is not necessary. Improved hearing may likely be achieved with a second procedure, but this is at the patient's discretion.

Adolescent↗
PubMed1992

Hyperbaric oxygen therapy: effect on middle ear and eustachian tube function.

Hyperbaric oxygen therapy (HBO) involves intermittent inhalation of 100% oxygen under a pressure greater than 1 atm. It is an important mode of adjuvant therapy for disease processes such as decompression sickness, osteomyelitis, carbon monoxide poisoning, and poorly healing wounds. Patients undergoing this therapy often complain of ear pain and/or fullness which can be transient or long standing. This prospective study objectively measured the changes in eustachian tube function before and after HBO treatment in 33 adult patients by the 9-step inflation-deflation test described by Bluestone. The results show 15 of the 33 patients (45%) had evidence of eustachian tube dysfunction after treatment was initiated. Of these, 15 (100%) developed the sensation of fullness, 13 (87%) developed serous otitis media, and 7 (47%) required tympanostomy tubes. The overall incidence of middle ear problems was 27 patients (82%) experiencing a sensation of fullness, 17 (52%) developing serous otitis media, and 8 (24%) requiring tympanostomy tubes. The middle ear complications reported in this study are much higher than those in previous reports in the literature. Twelve of 33 patients presented with a subjective history of eustachian tube dysfunction, and all 12 (100%) developed fullness in their ears and serous otitis media during the course of the treatment. The findings reveal that patients manifesting eustachian tube dysfunction after their first HBO treatment were at significantly greater risk toward developing symptoms of fullness and serous otitis media, often requiring tympanostomy tube placement. In addition, a history of eustachian tube dysfunction accurately predicted the development of fullness and serous otitis media.

Acoustic Impedance Tests↗
PubMed1992

Beta 2 transferrin application in otology.

The diagnosis and management of perilymphatic fistula has received considerable attention in recent years. Despite the use of sophisticated technology, the diagnosis of perilymphatic fistula continues to rest primarily upon clinical suspicion and the exclusion of other disorders. In addition, the confirmation of a perilymphatic fistula during surgical exploration is usually based upon the subjective observation of fluid pooling in niches of the middle ear. A sensitive and objective laboratory test for identifying perilymph in the middle ear would be a useful adjunct for the diagnosis and management of perilymphatic fistula. The objective of this paper is to demonstrate the potential utility of beta 2 (beta 2) transferrin assay in the diagnosis of perilymphatic fistula. To accomplish this objective, we confirmed that beta 2 transferrin is present in living human perilymph and is absent in the normal or inflamed middle ear. In addition, the utility of beta 2 transferrin assay in the diagnosis of cerebrospinal fluid otorrhea is presented.

Aged↗
PubMed1991

Bell's palsy. A diagnosis of exclusion.

In cases of acute unilateral facial weakness, a careful and systematic evaluation is necessary to identify the cause. Idiopathic facial paralysis (Bell's palsy) is a diagnosis of exclusion. It is also the most common cause of unilateral facial weakness seen by primary care physicians. The most important aspect of initial treatment is eye protection. Administration of systemic oral corticosteroids may lessen severity and duration of symptoms.

Adrenal Cortex Hormones↗
PubMed1991

Instillation of vancomycin into a cerebrospinal fluid reservoir to clear infection: pharmacokinetic considerations.

Vancomycin instilled in an Ommaya reservoir was used to treat a reservoir-associated infection. Vancomycin concentrations in cerebrospinal fluid (CSF) were measured, and derivation of pharmacokinetic parameters allowed tailoring of dosing. First-order kinetics were observed. The calculated half-life of 3.52 h was less than reported by others, and the apparent volume of distribution (60 ml) was less than anticipated. The elimination constant was 0.197 h-1. Empiric dosing based on schedules suggested in the literature would have led to high peak and low mean concentrations of intrareservoir vancomycin. Patients with reservoir-associated infections have a variety of pathophysiologic conditions that can result in alteration of normal CSF dynamics. Pharmacokinetic analysis is useful to individualize dosing and to optimize therapy with intrareservoir vancomycin.

Adult↗
PubMed1991

Abscess of the sphenoid sinus after transsphenoidal surgery.

A case of a bacterial abscess developing in the sphenoid sinus 2 weeks after transsphenoidal surgery is presented. Although abscesses within the sella turcica have been reported as rare complications of transsphenoidal surgery, this is the first reported case of the postoperative formation of an abscess of the sphenoid sinus. The patient sought treatment for severe headaches, nausea and vomiting, and marked temperature elevation. A computed tomographic scan demonstrated soft tissue and air within the sphenoid sinus. A regimen of stress doses of hydrocortisone and antibiotics was prescribed, and the patient underwent transsphenoidal drainage of the sphenoid sinus. The sella turcica was not involved. Anaerobic cultures were positive for Fusobacterium necrophorum.

Abscess↗
PubMed1991

Dehiscent temporomandibular joint.

The appearance of an acute effusion in a well-pneumatized temporal bone directs attention to the nasopharynx and skull base. Two patients are described in whom dehiscence of the temporomandibular joint allowed herniation of the contents of the joint posteromedically, where they obstructed the middle ear entrance of the eustachian tube, the protympanum. This is, to the authors' knowledge, a previously unreported cause of an acute middle ear and mastoid effusion.

Adolescent↗