Thomas L. Eby

Postnatal Growth of the Human Temporal Bone Implications for Cochlear Implants in Children

Recent interest in cochlear implantation for children has made it important to understand how postnatal growth of the ear will affect such devices. In this study, the postnatal growth of the labyrinth, middle ear, and mastoid was measured in three dimensions using radiographic and temporal bone data. Measurements were made from histologic sections of 48 temporal bones from children and compared to adult temporal bones. Radiographic measurements were made from 253 sets of skull radiographs of children and compared to adult skull series. In the three dimensions measured, there was no postnatal growth of the labyrinth and little variation in size between individuals. Measurements of the middle ear showed greater variation between individuals than measurements of the inner ear, but growth only in the distance from stapes footplate to the tympanic membrane. The mastoid showed growth in all three dimensions: length, width, and depth. The pattern of growth for mastoid length and width appears to follow a double logistic model, with differences between males and females. The growth in mastoid depth is smaller and appears to follow a single exponential curve. The implications for cochlear implantation in children are discussed.

The current status of audiologic rehabilitation for profound unilateral sensorineural hearing loss

Audiologic rehabilitation of individuals with profound unilateral sensorineural hearing loss (USNHL) has traditionally been limited to the use of air‐conduction contralateral routing of sound (CROS) hearing aids. Treatment for these individuals has expanded with new applications of the bone‐anchored hearing aid (BAHA), transcranial hearing aid (t‐CROS), and the cochlear implant. In this article, the authors review the literature that addresses these various treatment options.

Meningitis After Cochlear Implantation in Mondini Malformation

Although the potential for CSF leakage and subsequent meningitis after cochlear implantation in the malformed cochlea has been recognized, this complication has not been previously reported. We report a case of CSF otorhinorrhea and meningitis after minor head trauma developing 2 years after cochlear implantation in a child with Mondini malformation. Leakage of CSF was identified from the cochleostomy around the electrode of the implant, and this leak was sealed with a temporalis fascia and muscle plug. Although this complication appears to be rare, care must be taken to seal the cochleostomy in children with inner ear malformations at the initial surgery, and any episode of meningitis after surgery must be thoroughly investigated to rule out CSF leakage from the labyrinth.

Development of the facial recess : Implications for cochlear implantation

More attention is being focused on the growth and development of the facial recess because of the use of cochlear implantation in children over 2 years of age and the prospect of using implants in even younger children. The facial recess and the extended facial recess were measured in 123 temporal bones from 73 individuals ranging in age from 8 weeks in utero to 7 years after birth. The goals were to trace the development of the facial recess and to determine whether this area continues to grow into childhood.

Adenomas of the temporal bone.

Three cases of primary adenomas of the petrous bone are presented and compared to an adenoma arising from the external ear canal. In contrast to other adenomatous tumors, these caused slowly progressive inner ear symptoms without other signs, hence making differentiation from other benign lesions difficult. In one case, association with von Hippel-Lindau disease is suspected because of a strong family history and recent discovery of a similar lesion in the opposite ear. Bone destruction was found radiographically and clinically with vascular tumor tissue and cysts permeating the bone, causing adjacent bone destruction and remodeling. The histopathologic examination demonstrated this to be a benign process, however, with no direct tumor invasion or other signs of malignancy. Subtotal petrosectomy is a proven approach for complete removal of these tumors. Review of the literature revealed no previous reports of benign adenomas originating in the petrous bone.

Angioedema from angiotensin converting enzyme inhibitors: a cause of upper airway obstruction.

Angiotensin‐converting enzyme (ACE) inhibitors have several side effects of concern to the otolaryngologist. Angioedema is a rare, but potentially lethal adverse effect when associated with upper airway obstruction. Four cases of ACE‐inhibitor‐induced angioedema, three with significant upper airway obstruction, are reported.

New Aspects of Facial Nerve Pathology in Temporal Bone Fractures

Electron microscopic examination of intratemporal facial nerve segments removed from 12 patients with persisting facial paralysis following temporal bone fractures revealed that traumatic injury at the geniculum induces retrograde degeneration through the labyrinthine and distal meatal segments of the facial nerve. Fibrosis may occur in the traumatized labyrinthine segment and block regenerating motor fibers. The surgical treatment of traumatic facial nerve injuries should be aimed to avoid or eliminate fibrosis within the labyrinthine segment of the Fallopian canal.

Analysis of the efficiency of retrocochlear screening

The auditory brainstem response (ABR), as well as associated audiologic and radiographic studies of 175 patients suspected of having cerebellopontine angle tumors were reviewed. The majority of patients presented with asymmetric hearing loss. Eight acoustic neuromas were identified. All eight had abnormal ABRs. The false‐positive rate was 22%. Rollover and acoustic reflex testing played a minimal role in the decision as to whether or not an ABR was ordered and, as a result, are not important in the search for retrocochlear disease. The cost per tumor diagnosed was roughly

Use of intradermal dilutional testing and skin prick testing: clinical relevance and cost efficiency.

7600. A rational approach to tumor screening based on the efficiency and cost of the screening tests, the frequency of abnormal ABRs, and the cost per tumor diagnosed is presented.

Frequency tuning of bone-conducted tone burst-evoked myogenic potentials recorded from extraocular muscles (BOVEMP) in normal human subjects.

Objectives/Hypothesis: The objective was to determine the agreement of the positive results from a multiple skin prick test (SPT) device with the ability to determine a definable endpoint through intradermal dilutional testing (IDT) to compare semiquantitatively the degree of positivity of SPT results with quantitative results from IDT and to analyze the cost of immunotherapy based on SPT compared with IDT guided by SPT.