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Age-related declines in auditory and vestibular function are becoming more prevalent and better understood. The personal and societal impact of these disorders is impressive, and present techniques of amplification or balance training can be of great benefit. However, many issues await investigation, and continued integration of ever-increasing technologies promises many new answers, and questions, in the future.

A temporal bone report is presented of a patient with progressive sensorineural hearing loss and advanced Paget's disease involving the skull. The histopathology reveals Pagetic bone invading the internal auditory canal and compressing the cochlear division of the VIIIth cranial nerve resulting in severe neural degeneration. There are no other histopathologic abnormalities present in the cochlea to explain the hearing loss. A low-frequency conductive hearing loss was also present, but no histopathologic correlate could be identified.

This review article summarizes the subject of neurolemmomas in and around the temporal bone and was written as a component paper for a symposium on surgery of the skull base. The paper primarily discusses solitary schwannomas of the facial nerve, vestibular schwannomas, and jugular foramen schwannomas relative to incidence, signs and symptoms, and preferential diagnostic and therapeutic options. General considerations such as multiple neurofibromatosis, current nomenclature, and malignancy are defined.

The radiographic observation of 50 patients, each having an enlarged (greater than 1.5 mm. diameter) vestibular aqueduct, are analyzed. In addition to the aqueduct other associated inner ear anomalies have been identified in 60% of this population including: enlarged vestibule (14); enlarged vestibule and lateral semicircular canal (7); enlarged vestibule and hypoplastic cochlea (4); and hypoplastic cochlea (4). The large equeduct then presumably represents an arrested phase of inner ear development common to all 50 cases. Only 8 of these cases may fall into the Mondini or Mondini-Alexander classification wherein cochlear abnormalities have been identified. The size of the aqueduct ranged from 1.5 to 8 mm. in the anteroposterior diameter; the clinical incidence is 50 in 3700 consecutive cases referred for inner ear tomography. Bilateral involvement is twice as common as unilateral with a female to male predominance of 3:2. Most cases are associated with congenital hearing losses.

The usefulness of a special audiometric test battery was analyzed in relation to overall and individual test efficiency for the diagnosis of retrocochlear disease. Data were collected and analyzed from 118 patients with 121 surgically confirmed acoustic neuromas and were compared with an earlier report of 200 similar cases. While audiologic testing plays a major role in the identification of retrocochlear disease, the test battery is not highly efficient. Eleven percent of our neuromas had no audiologic signs and, therefore, escaped audiologic detection. The efficiency of individual tests range from 47% to 77%, while the difference in efficiency between the tone-decay test (77%) and the entire battery (89%) indicates the continued need for more than one test. The low efficiency of some of the components justifies reappraisal and revision of the present test battery.

The acinic cell tumor of salivary gland origin, once thought to be benign, is now known to be an incidiously slow growing malignant neoplasm with lethal potential. While the degree of malignant behavior of individual acinic cell tumors is notably variable, all must be treated with aggression. Traditional and current methods of treatment are reviewed; and, in conjunction with the tumors herein reported, guidelines for managment of this uncommon malignancy are suggested. Four cases have been reviewed in detail and critically analyzed. The pathology, including features of both light and electron microscopy, in included--particularly in relation to the oncocytoid areas identified in from 10% to 40% of the parenchymal cells of our tumors. Since an accurate histopathologic diagnosis is the first step in the establishment of a proper treatment plan, pitfalls in histologic diagnosis have been stressed.

Epidermoid carcinoma and angiofibroma are the commonly diagnosed lesions of the nasopharynx. Less common are unusual tumors of epithelial origin as well as those from endothelial and mesenchymal precursors. Otolaryngologists must be knowledgeable in the literature associated with these tumors to facilitate early diagnosis and to institute appropriate therapy. Cases of verrucous carcinoma, inverted papilloma, adenoid cystic carcinoma, and extramedullary plasmacytoma are presented. Current literature is reviewed and accepted modes of treatment are outlined.

Intramuscular hemangioma is a distinct type of hemangioma occurring within skeletal muscle and making up less than one per cent of all hemangiomas. They occur most often in the trunk and extremities, perhaps beacuse of the larger muscle volume in thos areas. 13.5 per cent of intramuscular hemangiomas do occur in the head and neck region and for this reason they should be considered in the differential diagnosis of head and neck masses. The first case of an intramuscular hemangioma of the digastric muscle is presented and confirmed by electron microscopic sections. An interesting finding in this tumor is the proliferation of both endothelial cells and pericytes. Hemangiomas are classified according to vessel size; "large vessel" cavernous, "small vessel" capillary, and "mixed". Various etiologies and modalities of treatment are discussed, and total excision with ligation of the feeding vessels is advocated to prevent the high incidence of later recurrence.

Careful presurgical otologic assessment of the contralateral ear in acoustic tumor patients is essential, not only to establish baseline data but more importantly to resolve the intense patient anxiety that arises almost immediately when the diagnosis is presented. Any subsequent reduction in hearing acuity in the contralateral ear after the tumor ear has been deafened, poses serious psychological, socio-economic and medical problems. Three detailed case reports of sudden hearing loss in the contralateral ear of postoperative acoustic tumor patients are presented. The lesion sites include: the middle ear, cochlear, and retrocochlear. In each case, hearing returned to its previous or near-previous levels. Allergic factors were implicated in two cases.

Allergic factors are important, but not the only etiologic force in middle ear effusion. Nor do bacterial and viral infections, nasopharyngeal mass lesions, neuromuscular or regional anatomic abnormalities rank as sole etiologic factors. Some children have multiple components to their problem that requires specific identification before a workable approach to management can be tailored for each of them. Identification and management of allergic factors requires special skills and a greater commitment of time. Yet the marked increase in total yield when allergic techniques are added to the armamentarium of the otolaryngologist make these factors both worthwhile and satisfying.

There is no single specific therapy for the treatment of middle ear effusions and, therefore, a holistic approach to management is necessary. Current management involves multiple therapeutic modalities of which we believe tube and allergy are most efficient.

Hypoglossal-facial anastomosis has been our procedure of choice in the repair of the permanently injured facial nerve in the cerebellopontine cistern, when the nerve cannot be primarily repaired. Total failures are few and complications are rare. Most results are good to excellent, if assessment is based upon realistic expectations. These include: 1. normal facial symmetry in repose, 2. good midface voluntary motion, 3. no reflex or emotional facial movement, 4. some synkinesis and donor-injected mass facial movement, and 5. surprisingly little functional loss from hypoglossal paralysis. Our experience indicates better results in younger patients and in those repairs completed shortly after injury. These findings correlate well with the experience gained in peripheral nerve repair in the extremities. There appears to be no absolute time period between injury and repair beyond which this anastomosis is definitely contraindicated. Finally, this procedure does not negate adjunctive plastic surgical procedures. Most of our patients have had tarsorrhaphy or physiologic protection of the eye, but few have had corrective cosmetic surgical procedures until the past few years. We have never used cervical sympathectomy to reduce the size of the palpebral fissure. Better surgical procedures to correct both extracranial and intratemporal facial nerve injuries have significantly reduced the indication for anatomosis procedures. Additionally, over the past two decades, the improved diagnostic and surgical techniques for posterior fossa tumors have considerably reduced the incidence of facial paralysis. As these trends continue, the number of patients requiring nerve anastomosis for facial paralysis will continue to decline and what was once the only surgical procedure to repair the paralyzed face will become a rare operation.

This article presents an overview of the points to be made both for and against the consideration of hearing conservation in acoustic tumor surgery based on current available data in the literature. Age, general health, tumor size, and hearing - in the tumor ear and in the contralateral ear as well as the interaural relationship - are the presurgical factors discussed. Either the middle fossa or posterior fossa approach may be utilized for hearing conservation. The technical factors relating to surgical anatomy, specific risks, and the probability that hearing may be preserved by these approaches have been abstracted from a review of the literature. Finally, the patient's considerations and his need for the conservation of his hearing are presented, including realistic alternatives to surgical conservation.

Hearing conservation in acoustic tumor surgery is an admirable goal and a logical extension of micro neurotologic surgery, but ideal candidates for conservation are few, and attempts to preserve hearing in those few fail in about half of all cases. Conserved hearing most often falls far beyond a range that will provide binaural function and is, therefore, of questionable use. The problem of hearing conservation in acoustic tumor surgery is rationally approached based upon the implications of the total presurgical overview, particularly with reference to age, general health, tumor size, and especially hearing in the tumor ear, the contralateral ear, and interaural relationships. Technical considerations, the morbidity and mortality, and, finally, probability factors are reviewed from the literature, The patient's consideration regarding potentials for hearing conservation, his need for conservation, and alternative options are discussed. Rehabilitative options for unilateral hearing impairment are discussed. A review of the amplification requirements of 45 acoustic tumor patients - 5 or more years postoperative - indicated that three-quarters had normal hearing in the contralateral ear, 24% of whom required CROS amplification; 67% of the remaining quarter had mild to moderate hearing losses and were effectively wearing BiCROS aids. None were rehabilitated with monaural aids; 20% of the entire group studied had demonstrated some degree of additional hearing loss in the non-tumor ear since surgery.

Three parameters of the acoustic reflex have been used in otoneurologic diagnosis: threshold (ART), decay (ARD), and latency (ARL). Each test is defined, put in historical perspective, and discussed in relation to diagnostic implications. We recommend that these three tests - ART, ARD, and ARL - be used as a group and describe how they are implemented in the audiologic diagnosis of acoustic tumors and other lesions affecting the auditory system in the cerebellopontine angle and brain stem.

This study evaluates the diagnostic sensitivity of a simple method of producing bidirectional cupular deviation using a monothermal stimulus. This stimulus has the advantage of conservation of time and increased patient comfort and acceptance (two caloric irrigations instead of four). Each patient was seated with his head extended 60 degrees during the caloric irrigation. Eighty seconds after the onset of irrigation, the patient placed his head forward, thereby causing both an ampullopetal and ampullofugal flow of endolymph. Right/left difference and directional preponderance were computed for both monothermal warm and monothermal cold irrigations and compared to the traditional bithermal caloric results. This study comprised a control group of 13 normal patients and 144 dizzy patients. False positive (abnormal monothermal but normal bithermal) and false negative (normal monothermal but abnormal bithermal) tests occurred in 45 percent and 50 percent of examinations, respectively. Inaccurate measurement of the weak slow phase velocity that usually accompanies the inverted position was a probable cause of the poor correlation between test results since a separate analysis of electronystagmograms with more intense nystagmus in the inverted position resulted in an improved correlation. Further evaluation of this technique should include methods that result in more accurate measurement of slow phase velocity.

Acoustic reflex latency is the time interval between onset of an intense auditory stimulus and onset of middle-ear muscle contraction. The hypothesis was proposed that a retrocochlear lesion involving the afferent (VIIIth nerve) portion of the reflex arc should result in a prolongation of the reflex latency. A clinical procedure, the Acoustic Reflex Latency Test (ARLT), its protocol, methods and equipment were developed in order to test this hypothesis clinically. Absolute latency values and interaural latency differences (ILD) were established on 4 populations which included normals, cochlear lesions due to Ménière's disease, cochlear lesions of variable etiology, and 11 cases of surgically confirmed acoustic tumor. Results reveal a dramatic prolongation of latency in the presence of retrocochlear lesions (all tumors). The test was found to be most effective when 1. both ipsilateral and contralateral measurements were made, 2. stimulus frequencies of 100 Hz and 2000 Hz were employed and 3. both Absolute Latency and ILD were considered. The ARLT, while utilizing an indirect method of measurement, is a valid, cost-effective, and simple clinical procedure, yielding relative latency values and requiring only minor modifications of standard impedance equipment. The ARLT appears to have a higher efficiency rate than BERA, while providing comparable diagnostic information at a considerable saving of time, cost and personnel.

Auditory brain stem response (ABR) thresholds for tone pip stimuli were compared with audiometric thresholds for 63 ears to assess the feasibility of deriving audiograms with ABR techniques. Correlations between the two measures were highly significant, indicating a high degree of accuracy in assessing degree and configuration of hearing loss with ABR. Patients with conductive losses showed a simple one-to-one relationship between ABR and audiometric thresholds, while patients with cochlear losses did not. Possibly this is due to the effects of abnormal temporal integration or poor frequency selectivity in this latter group.

Changes in auditory pure tone threshold and speech discrimination and the phase and gain in the sinusoidal harmonic acceleration test were measured in subjects with endolymphatic hydrops (Meniere's disease) following the administration of glycerol. Although all subjects showed a marked improvement in auditory function, a comparable change in vestibular function, as measured by the sinusoidal harmonic acceleration test, was not observed.

The acoustic reflex latency test (ARLT), an indirect measure of neural conduction time utilizing the electroimpedance method, was used to evaluate 43 highly suspect, nontumor patients who demonstrated abnormal latency results on brainstem electric response audiometry (BERA), false-positive for tumor. Normative values and criteria for tumor-positive ARLT results were established on a control group using a second generation test unit, comprised of dual impedance bridges and a digital signal averager, designed especially to perform the ARLT. When cut-off criteria for both absolute reflex latency and interaural latency difference (ILD) values were applied to this BERA false positive population, the ARLT correctly identified 93% of patients as having end-organ lesions. Differences in ARLT and BERA test results are attributed to differences in 1) method of measurement, 2) characteristics of the eliciting signal, and 3) generation of the response. These factors are discussed as sources of variability. Both ARLT and BERA are recommended as tandem procedures when screening for acoustic or angle tumors.

There are several applications of and advantages to using an insert earphone. An insert earphone has three parts: a transducer to convert electrical energy to sound, a conduit to deliver the sound into the ear canal, and a coupler connecting the device to the canal. The data from this study indicate that there is a distinct advantage in using insert earphones over TDH-49 phones (standard headphones) in the attenuation of low frequency ambient noise. The use of insert earphones will permit one to test hearing in areas of higher ambient noise than was previously possible. Insert earphones are used to shorten the hearing aid selection process. A technique is described in which only one real ear measurement is required for an accurate hearing aid fitting. Most, but not all, of the masking dilemmas that are encountered with standard headphones are circumvented or eliminated by using insert earphones. In brain stem auditory evoked response testing, the insert earphone reduces the stimulus artifact without influencing the acoustic signal. Finally, the insert earphone solves the collapsing ear canal problem.

The American Hearing Research Foundation has developed a regional Infant Screening Program in the state of Illinois, designed to meet the vital need for early identification of hearing impairment on a mass scale. The four major components of the program include: 1. Application of the High Risk Register to the general newborn population, 2. Hearing Screening in the Intensive Care Nursery, 3. Electrophysiologic confirmation with Brain Stem Electric Response testing and 4. Subsequent and immediate remediation and/or habilitation. Brain Stem Electric Response Audiometry (BERA) has been shown to be an accurate and sensitive clinical tool for obtaining auditory thresholds in infants from birth. At the Donald T. Forsythe Otologic Laboratory in Mercy Hospital, Chicago, IL, over 250 infants and young children have been tested in a controlled study with BERA to establish or rule-out the diagnosis of hearing impairment. The use of BERA preceded by screening of a refined neonatal population has proven to be an effective method of early identification. The goals of the program are: 1. To identify hearing impaired children prior to passage of the critical periods, 2. To medically or surgically classify and treat and/or auditorily habilitate, and 3. To ultimately improve the quality of life of the child born with hearing impairment.

The coexistence of an acoustic neuroma with otosclerosis can prove to be a great diagnostic dilemma. In such cases, the diagnosis of acoustic neuroma is usually delayed while more common causes of sensorineural hearing loss associated with otosclerosis or its surgery are considered. Any asymmetric progression of a sensorineural loss or shift in discrimination after stapes surgery, whether sudden or gradual, should provoke suspicion of a second pathologic process. These include perilymph fistula, labyrinthine otosclerosis or ischemia, and acoustic neuroma. The use of auditory brainstem response and acoustic reflex testing and various imaging techniques is essential for accurate diagnosis. This paper includes two cases that demonstrate this dual pathology, bringing the total to 15 such cases reported in the literature. The purposes of this paper are to alert the clinician to the diagnostic problem of acoustic neuroma coexisting with otosclerosis and to propose a means of evaluating these patients.

Hydrocephalus has been identified and surgically treated with ventricular peritoneal shunts in two of 150 patients following translabyrinthine microsurgical removal of acoustic tumors. This problem has prompted a review of the subject of hydrocephalus in general and "otitic hydrocephalus" in particular in relation to contemporary extended temporal bone surgery.

Our literature review has tabulated 33 jugular foramen neuromas that appeared either as a neurologic "syndrome of the jugular foramen" like a glomas tumor, or similar to an acoustic tumor. The few posterior fossa tumors involving the eighth nerve or encroaching upon it that have been removed and resulted in cochleovestibular preservation or recovery have been reviewed. A rare case of jugular foramen schwannoma with cochleovestibular preservation after total removal has been extensively studied with preoperative and postoperative cochleovestibular tests.

An attempt has been made through this study to establish a tumor suspect pool of 100 patients, each one highly suspect because of a single or usually several strong clinical indicators of a retrocochlear lesion. In turn each patient has been proven tumor negative by virtue of a normal opaque cerebellopontine cisternogram. This has given us a unique opportunity to critically reassess the clinical indications of VIIIth nerve tumor from a reverse or negative viewpoint. All data from these patients has been carefully analyzed in relation to indication for opaque cisternography, clinical symptomatology, vestibular function, final etiologic diagnosis, and the associated special auditory tests, tomograph of the internal auditory canal, the associated vestibular aqueduct findings. This paper parallels our earlier study of 121 surgically proven schwannomas providing a total tumor suspect pool of 221 patients with a comparable tumor positive-tumor negative distribution.

Nineteen normal and 22 hearing impaired subjects were used in this study. Thresholds were determined by the following methods: 1. behavioral continuous tone, 2. behavioral tone burst, and 3. the brain stem electric response (BER) with tone bursts. A comparison of the BER thresholds with the behavioral thresholds are made for each subject. The difference between these three measures of threshold suggests that audiograms can be derived from the brain stem response threshold. The derived audiogram compares favorably with conventional audiograms. However, it must be remembered that the brain stem response is not hearing.

Until quite recently, acoustic tumors were not diagnosed until they had reached relatively large size. Vestibular function tests were positive in a large percentage of these cases. Since vestibular function tests are limited to lesions of the superior branch of the vestibular nerve, it was thought that 90% of vestibular schwannomas arose from the superior vestibular nerve. Recently, as the diagnostic efficiency of auditory tests has improved, many small tumors are being detected. As the size of the tumors decreases, the efficiency of vestibular function testing has also decreased. A review of histologic and surgical literature demonstrates that the earlier estimate is inaccurate, and that only 50% of vestibular schwannomas originate on the superior branch of the vestibular nerve. This warrants a critical review of the value of vestibular function tests in the evaluation of suspected vestibular schwannomas.

Nuclei of human neurilemoma cells exhibit deep and extensive invaginations of part of their surface. Such invaginations contain cytoplasmic matter. However, in areas of the nucleoplasm distant from the invaginations, small membrane-bound bodies, some of which contain a "nucleoid," occur either singly or grouped together and enclosed within a large membrane body. These small bodies are not considered virus-like. Degenerated nuclei from cultured tumor tissue contain spherical bodies, 130 to 230 nm in diameter, with spikes on their surface similar to those seen on envelopes of herpes-type viruses. Significance of these bodies in vivo and in vitro tumor tissues is not known.

The purpose of this paper is not to propose that auditory brainstem response (ABR) be utilized for the assessment of conductive losses, but to define the effects of conductive hearing loss on the ABR when such a complication occurs. Conductive losses attenuate cochlear stimulation. Since wave V latency is inversely related to stimulus intensity, the magnitude of the conductive loss should be a predictor of the wave V latency delay. In this study, ABR wave V latencies from patients with known conductive losses due to canal occlusion, middle ear effusion, ossicular fixation and chain interruption were compared with latency values calculated from the magnitude of the loss. In those patients with occlusion of the external auditory canal and middle ear effusion, the shift of the wave V latency-intensity function correlated well with the air-bone gap. This correlation was poor for patients with ossicular chain disorders. In mixed hearing losses, the increased wave V latency due to the conductive component may totally mask an increase in latency caused by a retrocochlear component.