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Biomedical subjects

B E Hirsch

Publications and source records attributed to B E Hirsch.

At least 37 records · Page 2Linked to original sources
PubMed1998

Beyond the promontory: the multifocal origin of glomus tympanicum tumors.

PURPOSE: We examined other middle ear locations of glomus tympanicum tumors, which arise from glomus bodies accompanying the tympanic (Jacobson's) nerve through the middle ear. Most descriptions place these tumors on the promontory over the basal turn of the cochlea. METHODS: We identified seven patients (all women) with small surgically confirmed glomus tympanicum tumors (not completely filling the middle ear) for whom CT scans were available for retrospective review. Patients' ages ranged from 23 to 78 years at the time of the high-resolution CT study (1.0- to 1.5-mm-thick sections). RESULTS: All tumors arose on the medial wall of the middle ear. One was anterior to the promontory, beneath the cochleariform process and the semicanal of the tensor tympani. Two were inferior to the promontory, in the recess beneath the basal turn of the cochlea. Four were anteroinferior. None was actually on the apex of the promontory. CONCLUSION: Glomus tympanicum tumors may arise in various locations on the medial wall of the middle ear, where Jacobson's nerve runs. The promontory is only one middle ear location in which glomus tympanicum tumors may arise. Familiarity with the course of the tympanic nerve helps tailor the search for, and facilitates accurate identification of, tiny glomus tympanicum tumors.

Adult↗
PubMed1997

Intratympanic gentamicin therapy for Ménière's disease.

OBJECTIVE: To evaluate the efficacy and toxicity of intratympanic gentamicin therapy for the treatment of Meniere's disease. STUDY DESIGN: We compared retrospective case series with historical controls. SETTING: A tertiary referral center--the ambulatory clinic at The University of Pittsburgh Medical Center. PATIENTS: The study consisted of 28 patients with Meniere's disease who failed conventional medical therapy and were offered gentamicin treatment or surgical intervention. Patients had to be followed for at least 2 years to be eligible for review. INTERVENTION: Intratympanic gentamicin solution injections were given by serial titration to the involved ear on a weekly or biweekly schedule. MAIN OUTCOME MEASURES: Adhering to the American Academy of Otolaryngology--Head and Neck Surgery 1985 criteria for reporting treatment results in Meniere's disease, the hearing status, control of vertigo, and disability scores using intratympanic gentamicin therapy were reported and compared with historical controls. RESULTS: Complete or substantial control of vertigo was achieved in 91% of patients. Hearing loss occurred in approximately one third of patients. Historically, similar hearing loss occurs in patients who were treated successfully, either medically or surgically. Ototoxicity (high frequency hearing loss) was more likely to be seen in patients with pre-treatment 8,000 Hz hearing thresholds better than 65dB. CONCLUSIONS: Intratympanic gentamicin therapy given by serial titration injections provides significant control of vertigo without the significant cost and potential morbidity of a more invasive surgical procedure.

Adult↗
PubMed1997

The evolving MR appearance of structures in the internal auditory canal after removal of an acoustic neuroma.

PURPOSE: To identify patterns of enhancement in the internal auditory canal (IAC) on MR studies after removal of an acoustic neuroma, including changes in those patterns with time; to evaluate signal and enhancement of the labyrinth; to differentiate normal postoperative findings from those suggesting residual tumor; and to describe MR hallmarks of surgical approaches. METHODS: We reviewed the postoperative MR studies obtained in 36 patients who had had surgery for acoustic neuroma (101 images total). Four patterns of IAC enhancement were evaluated, as was labyrinthine signal intensity before and after contrast administration, changes in findings over time, and anatomic alterations caused by surgery. RESULTS: All patients had enhancement of the IAC on the first postoperative study. In 30 patients, IAC enhancement remained the same or decreased over time. Seventeen patients had hyperintense cochlear signal and 15 had cochlear enhancement that decreased with time. Effects of retrosigmoid craniotomy, a translabyrinthine surgical approach, and middle fossa craniotomy were recognizable. CONCLUSION: Linear enhancement in the IAC is probably normal after surgery. Nodular and masslike enhancement and any progressive enhancement may require close follow-up to monitor growth of residual tumor. Labyrinthine hyperintensity may reflect blood metabolites. An MR protocol is suggested for following up patients in the years after surgery.

Adolescent↗
PubMed1997

Role of chemical labyrinthectomy in the treatment of Meniere's disease.

Medical management of Meniere's disease is successful in approximately 70% of patients. Surgical intervention is the treatment option when medication fails. Middle ear installation of aminoglycosides provides significant control of vertigo. This article addresses the role of aminoglycoside ablation of vestibular function in Meniere's disease.

Ear, Inner↗
PubMed1996

Clinical applications of three-dimensional magnetic resonance image analysis.

A methodology for measuring the kinematic parameters of joints in vivo has been refined using the technique of computerized three-dimensional reconstruction from magnetic resonance images. A research protocol has been developed to establish a classification of normal and pathologic foot function that will have broad clinical application. Development of algorithms for a computer-directed program that can predict resultant kinematics and joint morphometry for a given osteotomy or osseous remodeling procedure will assist the surgeon in preoperative surgical planning.

Ankle↗
PubMed1996

New method of studying joint kinematics from three-dimensional reconstructions of MRI data.

A new method of measuring the kinematic parameters of joints has been developed. This article describes the procedure, using tarsal joints as examples. The method uses the technique of computerized three-dimensional reconstruction from magnetic resonance images, taken at regular intervals throughout a foot's range of motion. From these reconstructions, various kinematic information, such as orientation of instantaneous axes, amounts of rotation, amounts and direction of translation, and bony contact areas, is derived. The method is noninvasive and can be applied to individual subjects or patients.

Biomechanical Phenomena↗
PubMed1996

Localizing retrocochlear hearing loss.

PURPOSE: The origin of acute/sudden hearing loss is multifactorial. The association of vestibular symptoms does not necessarily isolate the pathologic condition to the inner ear. The audiogram provides a screen for differentiating conductive from sensorineural loss but often fails to provide more localizing information. METHODS: Three unusual patients with a variety of retrocochlear presentations of hearing loss are presented. Along with conventional auditory brainstem response (ABR) testing, newer auditory tests, including otoacoustic emissions and three-dimensional ABR analysis, can facilitate site-of-lesion testing. Magnetic resonance imaging (MRI) also provides graphic documentation for sources of retrocochlear hearing loss. RESULTS: One patient had gamma-knife treatment of an arteriovenous malformation, incurring a localised lesion to the inferior colliculus contralateral to the side of hearing loss. This effectively eliminated wave V, as confirmed by three-dimensional ABR analysis. A second patient with human immunodeficiency virus developed sudden complete hearing loss with retained otoacoustic emissions, confirming a retrocochlear lesion. A third patient with acute otitis media with sudden hearing loss and vertigo had an abnormal ABR and "mass lesion" on MRI. Hearing subsequently returned to normal, as did a repeated scan. CONCLUSIONS: The unique aspects of each case of retrocochlear hearing loss and the applied auditory electrophysiologic tests are reviewed.

Adult↗
PubMed1996

Use of nimodipine in the medical treatment of Menière's disease: clinical experience.

PURPOSE: Nimodipine is a highly lipophilic, centrally acting calcium channel blocker. It is similar in action to flunarizine, which has been studied for use in the medical treatment of Menière's disease. METHODS: Nimodipine was offered to patients with Menière's disease for whom first-line medical management failed (dietary restrictions and diuretics or vestibular suppressants). RESULTS: Our preliminary clinical experience using nimodipine in 12 patients with Menière's disease from December 1992 until March 1995 resulted in successful control of vertigo and hearing improvement or stabilization in seven (58%) of 12 patients. When hearing stabilization was not considered, eight (67%) patients had vertigo satisfactorily controlled (AAOO class A, B, or C). The four (33%) patients whose vertigo symptoms persisted despite treatment with nimodipine (AAOO class D) were surgically treated with successful vertigo control. Nimodipine was discontinued in one class D patient because of gastrointestinal intolerance. CONCLUSIONS: Nimodipine provides an alternative successful means for medical management of Menière's disease.

Calcium Channel Blockers↗
PubMed1996

The efficacy of tympanic electrocochleography in the diagnosis of endolymphatic hydrops.

Electrocochleography (ECoG), an objective electrophysiologic test, is useful in the clinical diagnosis of endolymphatic hydrops. The purpose of this study was further to define the role of ECoG in the diagnosis of this disease. A retrospective chart review of 100 patients undergoing tympanic ECoG was undertaken comparing symptoms, degree of hearing loss, duration of disease, and diagnosis with ECoG results. The apparent sensitivity and specificity of ECoG in the diagnosis of endolymphatic hydrops were determined to be 57% and 94%, respectively. Three of 30 positive ECoG results were falsely positive. Fluctuating hearing loss and the degree of hearing loss (< 40 dB) and duration of disease (< 48 months) were statistically significant in predicting positive ECoG results. We conclude that a positive ECoG result is helpful in objectively confirming the disease. However, a negative result does not rule out hydrops.

Adult↗
PubMed1996

Hydroxyapatite cement to repair skull base defects: radiologic appearance.

PURPOSE: To describe the radiologic appearance of hydroxyapatite cement (HAC), which, when mixed with liquid, forms a paste that can be contoured to osseous defects and, over time, becomes "osseointegrated" (native bone grows into the pores of the HAC and forms a strong chemical bond with the substance). METHODS: Between March 1992 and June 1993, 24 adults (16 men, eight women) underwent skull base surgery that included reconstruction or closure with HAC. Fourteen patients had HAC placed in the paranasal sinuses or facial bones, and 10 had HAC placed in the mastoid cavity. RESULTS: HAC is homogeneously radiopaque on CT scans and plain radiographs. Large amounts (ablating a frontal sinus or mastoid air cells) are readily seen; small amounts are inconspicuous. On MR images, HAC is a signal void. Infected HAC in one patient was surrounded be enhancing soft tissue on MR images, separated from native bone by an irregular radiolucent cleft on CT scans. CONCLUSIONS: HAC is a valuable addition to the surgical armamentarium for the repair of skull base defects. More experience will determine the time course for normal osseointegration, as well as the typical appearance of infection.

Adult↗
PubMed1995

Oculostapedial synkinesis.

A 51-year-old woman with persistent oculostapedial synkinesis after successful microvascular surgical decompression of the facial nerve in the cerebellopontine angle is presented. Auditory symptoms are common in patients with hemifacial spasm manifested by a low-pitch rumbling noise, ear fullness or stuffiness, subjective reduction of hearing acuity, and as described in this case, ear tightness and "drumming." Ephaptic neural transmission is the proposed cause of hemifacial spasm. The exacerbation of auditory symptoms with voluntary blinking and eye closure can be explained by ephaptic transmission and/or aberrant regeneration. Should the aggravating and annoying symptoms of stapedial muscle dysfunction persist in the face of successful treatment of hemifacial spasm, transmeatal division of the stapedial tendon provides immediate relief.

Facial Paralysis↗
PubMed1994

Evolution and advances of the lateral surgical approaches to cranial base neoplasms.

The evolution and advances of the lateral surgical approaches used for neoplasms of the cranial base involving the middle and posterior cranial fossa are reviewed. The lateral approaches available for access to the cranial base are diverse and are often used in combination. Approaches for tumors that are completely extradural, usually involving the temporal bone or infratemporal fossa, include the infratemporal fossa approach described by Fisch and the preauricular subtemporal-infratemporal fossa approach. Lateral approaches used to provide exposure of intradural tumors involving the clivus and traversing the middle and posterior cranial fossa are based on the following approaches: the frontotemporal orbitozygomatic, subtemporal/middle fossa, transpetrosal, lateral suboccipital, and transcondylar approaches. The great strides that have been made in the safe and effective surgical treatment of cranial base neoplasms are due, in part, to the availability of multiple surgical approaches and the ability to tailor the planned operative procedure to the precise location and extent of the cranial base tumor.

Carotid Arteries↗
PubMed1994

Panic in otolaryngology patients presenting with dizziness or hearing loss.

This study compared 50 patients presenting to an otolaryngology clinic with a complaint of dizziness and 50 patients presenting with hearing loss on questionnaire measures of panic, phobic avoidance, generalized anxiety, and depression. Clinical and laboratory evaluations of vestibular and audiological complaints were also completed. Twenty percent of the group with dizziness and none of the group with hearing loss reported symptoms that met DSM-III-R criteria for panic disorder. Patients with dizziness and peripheral vestibulopathy had more symptoms of phobic avoidance, generalized anxiety, and depression than patients with confirmed hearing loss.

Adult↗
PubMed1994

Imaging of ossicular prostheses.

The prostheses available for reconstruction of the ossicular chain have expanded to include a variety of synthetic materials. Hydroxyapatite contains the inorganic constituents found in human living bone and is currently being incorporated into many new prostheses. This study demonstrates the computed tomography and magnetic resonance image characteristics of eight middle ear prostheses, a block of dense hydroxyapatite, and a human incus. Imaging of ossicular prostheses is more informative with computed tomography.

Bone Substitutes↗
PubMed1994

Combined approaches for resection of extensive glomus jugulare tumors. A review of 12 cases.

Complete resection with conservation of cranial nerves is the primary goal of contemporary surgery for glomus jugulare tumors. This publication reports the value of combined surgical approaches in achieving this goal in 12 patients with extensive tumors. Eleven of these tumors were classified as Fisch Class C and/or D, while eight were categorized as Jackson-Glasscock Grade III or IV. Intracranial (intradural) extension was present in 10 patients; four patients had tumor extension into the clivus and two into the cavernous sinus. The petrous internal carotid artery (ICA) was involved in eight and the vertebral artery (VA) in one. Subtemporal-infratemporal, retrosigmoid, and/or extreme lateral transcondylar approaches were added to the usual transtemporal-infratemporal approach. This improved the exposure, provided early control of the petrous ICA, and facilitated tumor removal from the clivus, cavernous sinus, posterior fossa, and foramen magnum, allowing a single-stage resection in eight patients. Ten patients had a complete microscopic resection with no mortality. The facial nerve was preserved in nine cases, with tumor involvement requiring nerve resection followed by grafting in the remaining three. Mobilization of the facial nerve was avoided in five cases; of these, three had intact function and two had House-Brackmann Grade III function on follow-up review. Only one patient had a mild persistent swallowing difficulty. The ICA was preserved in 10 patients and resected in two, while the VA required reconstruction in one case. There were no instances of stroke, and blood transfusions were required in five patients who had tumors with nonembolizable ICA or VA feeders. While complete resection provides the best possibility for cure, the important role of adjuvant radiation therapy in cases with residual tumor is discussed. The importance of degrees of brain-stem compression and vascular encasement is emphasized in classifying the more extensive tumors.

Adult↗
PubMed1994

Hydroxyapatite cement: a new method for achieving watertight closure in transtemporal surgery.

Transtemporal approaches to the petrous apex and CP angle are standard procedures in the armamentarium of the neurotologist. In the majority of these cases, it is not possible to achieve a watertight suture closure of the dura following the procedure. Subsequently, cerebrospinal fluid leakage and potential meningitis are among the most troublesome complications for both patient and surgeon. Recent use of calcium phosphate cement (hydroxyapatite [HA]) has proved efficacious in animal studies and is now being used to close cranial defects in several medical centers, as part of an FDA-IDE study in human subjects. The use of this material is described in 11 neurotologic procedures. It is believed that hydroxyapatite cement (HAC) will become a standard tool in the management of cranial base and temporal bone defects following surgery.

Adult↗