A case of bilateral internal auditory canal osteomas.

Osteomas of the skull base are rare, benign, slowly progressing growths of dense cortical bone. Osteomas occurring in the internal auditory canal are extremely rare. These lesions have sometimes been linked with dizziness, sensorineural hearing loss, and/or tinnitus.

Effects of tensor tympani muscle contraction on the middle ear and markers of a contracted muscle.

Objectives/hypothesis: Many otologic disorders have been attributed to dysfunction of the tensor tympani muscle, including tinnitus, otalgia, Meniere's disease and sensorineural hearing loss. The objective of this study was to determine adequate stimuli for tensor tympani contraction in humans and determine markers of the hypercontracted state that could be used to detect this process in otologic disease.

Study Design: Multiple types of studies.

Prosthetic reconstruction from the tympanic membrane to the stapes head or to the stapes footplate? A laser Doppler study.

Background: In the absence of the incus, many surgeons believe that reconstruction from the tympanic membrane to the stapes head is more effective than reconstruction to the stapes footplate. This has rarely been tested empirically. Published better clinical results with reconstruction to the stapes head might simply reflect less underlying disease in ears with an intact stapes superstructure.

Effect of Silastic sheeting over the round window niche on sound transmission in the intact human middle ear.

Background: Silastic sheeting is commonly used in middle ear surgery to prevent the formation of adhesions between the tympanic membrane and the medial bony wall of the middle ear cavity. This sheeting is often placed, advertently or inadvertently, so as to cover the round window niche. The effects of mechanically shielding the round window niche in the presence of an intact tympanic membrane and ossicular chain have not been empirically studied to date.

Anatomic analysis of the mastoid tegmen: slopes and tegmen shape variances.

Objectives: To examine the dural slope shapes and slope depths in different axes in the mastoid. These are important for surgical guidance.

Study Design: Setting-Tertiary care otologic center.

Analysis of Vibrant Soundbridge placement against the round window membrane in a human cadaveric temporal bone model.

Objective: To evaluate optimal placement of the Floating Mass Transducer of the Vibrant Soundbridge (Med-El, Innsbruck, Austria) against the round window membrane, particularly the impact of interposed coupling fascia and of covering materials.

Method: : Six fresh human cadaveric temporal bones were used. After mastoidectomy, posterior tympanotomy and removal of the round window niche, the Floating Mass Transducer (FMT) of the Vibrant Soundbridge (VSB) was placed against the round window membrane (RWM) in the following ways: in direct contact, or with interposed fascia.

Simple mass loading of the tympanic membrane to alleviate symptoms of patulous eustachian tube.

Background: Patulous eustachian tube (PET) has a major impact on a patient's quality of life. The purpose of this study was to understand mechanisms behind the symptoms, develop treatments based on these, and develop and use a questionnaire to measure changes in PET symptoms with a novel intervention. Our hypothesis is that PET symptoms can be addressed at the level of the eardrum more easily than at the level of the eustachian tube.

High-frequency ex vivo ultrasound imaging of the auditory system.

A 50MHz array-based imaging system was used to obtain high-resolution images of the ear and auditory system. This previously described custom built imaging system (Brown et al. 2004a, 2004b; Brown and Lockwood 2005) is capable of 50 microm axial resolution, and lateral resolution varying from 80 microm to 130 microm over a 5.

Refractory severe facial nerve cross-stimulation and loss of auditory sensation after ten years of uneventful cochlear implant use. A rare and challenging case.

Facial nerve stimulation after cochlear implantation has been well described. When the implant is first activated it is usually possible to 'programme out' the unwanted cross-stimulation. We report an exceptional case of delayed facial nerve stimulation and auditory failure after ten years of uncomplicated implant use.

Linearity and lever ratio of the normal and reconstructed cadaveric human middle ear.

Hypothesis: The linearity and the level ratio are different in reconstructed ears.

Background: The linearity of the reconstructed human middle ear (ME) has not been previously explored. It is important to analyze if high sound pressure levels (SPLs) result in distortion due to nonlinearities particularly because hearing aids have high-output SPLs.

How does prosthesis head size affect vibration transmission in ossiculoplasty?

Objectives: The transmission of vibrations from the tympanic membrane to the stapes footplate by an ossicular reconstruction prosthesis is affected by the size of the prosthesis head. We sought to determine if augmenting or reducing the head size of prosthesis had a systematic effect on transmission of vibrations to the stapes.

Study Design: We conducted a fresh cadaveric temporal bone middle ear study.

Cochlear implantation in Cockayne syndrome: our experience of two cases with different outcomes.

Cockayne syndrome is a rare autosomal recessive defect in DNA repair resulting in a classic facies with potential visual and auditory impairment. The hearing loss begins peripherally and may become central as the condition progresses. Coexisting sensory deprivation from visual impairment and the possibility of progressive deterioration in mental function conspire with a lack of published experience to produce many challenges for the cochlear implant team.

Effects of ossicular prosthesis mass and section of the stapes tendon on middle ear transmission.

Background: The effects of changing prosthesis mass on middle ear transmission have not been previously systematically studied. Neither has the effect of stapes tendon sectioning. These are important parameters that can be surgically varied.

Is duration tuning a transient process in the inferior colliculus of guinea pigs?

Duration selectivity appears to be a fundamental neural encoding mechanism found throughout the animal kingdom. Previous studies reported that band-pass duration-tuned neurons typically show offset responses and occupy a small portion of auditory neurons in non-echolocation mammals relative to echolocation bats. Therefore, duration tuning is generally weaker in non-echolocation mammals.

Output vibration measurements of bone-anchored hearing AIDS.

Hypothesis: Different bone-anchored hearing aids (BAHAs) processors have different output vibration characteristics, which depend on the mechanical load and the volume setting. Responses will differ between live heads and dry or plastic skulls.

Background: The BAHA is an implantable bone-conduction device.

Is there loss of vibration amplitude across the snap coupling of the bone-anchored hearing aid?

Hypothesis: There is loss of vibration transmission across the snap coupling connecting the Bone-Anchored Hearing Aid transducer to the implanted abutment on the head.

Background: The only nonrigid part of the Bone-Anchored Hearing Aid system is the connection between the output of the transducer and the abutment. Vibration losses across the coupling have not been previously measured.

Effect of adhesion on the acoustic functioning of partial ossicular replacement prostheses in the cadaveric human ear.

Background: Adhesion formation following ossiculoplasty surgery has been implicated as a cause of the progressive deterioration of an initially good postoperative hearing result. Scar tissue between the partial ossicular reconstruction prosthesis (PORP) and adjacent middle ear structures is a common finding at revision surgery.

Objectives: This study aims to investigate the effects of simulated scarring on the microacoustic transmission characteristics of a PORP in the fresh cadaveric human temporal bone.

How do cartilage and other material overlay over a prosthesis affect its vibration transmission properties in ossiculoplasty?

Objective: The prosthesis/eardrum interface is often deliberately modified by cartilage overlay, or by soft tissue in-growth. We examined the effects of vibration transmission to the footplate of inserting cartilage of varying sizes, and materials of varying rigidities.

Study Design And Setting: Using fresh human cadaveric temporal bones, stapes vibrations were measured.

Optimum tension for partial ossicular replacement prosthesis reconstruction in the human middle ear.

Objective: Hearing results from ossiculoplasty are unpredictable. There are many potentially modifiable parameters. One parameter that has not been adequately investigated in the past is the effect of tension on the mechanical functioning of the prosthesis.