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J D Clemis

Publications and source records attributed to J D Clemis.

At least 19 recordsLinked to original sources
PubMed1991

Electromagnetic semi-implantable hearing device: phase I. Clinical trials.

Conventional hearing aids have improved significantly in recent years; however, amplification of sound within the external auditory canal creates a number of intrinsic problems, including acoustic feedback and the need for a tight ear mold to increase usable gain. Nonacoustic alternatives which could obviate these encumbrances have not become practical due to inefficient coupling (piezoelectric techniques) or unfeasible power requirements (electromagnetic techniques). Recent technical advances, however, prompted a major clinical investigation of a new electromagnetic, semi-implantable hearing device. This study presents the details of clinical phase I, in which an electromagnetic driver was coupled with a target magnet temporarily affixed onto the lateral surface of the malleus of six hearing aid users with sensorineural losses. The results indicate that the electromagnetic hearing device provides sufficient gain and output characteristics to benefit individuals with sensorineural hearing loss. Significant improvements compared to conventional hearing aids were noted in pure-tone testing and, to a lesser degree, in speech discrimination. Subjective responses were quite favorable, indicating that the electromagnetic hearing device 1. produces no acoustic feedback; 2. works well in noisy environments; and 3. provides a more quiet, natural sound than patients' conventional hearing aids. These favorable results led to phase II of the project, in which patients with surgically amendable mixed hearing losses were implanted with the target magnet incorporated within a hydroxyapatite ossicular prosthesis. The results of this second-stage investigation were also encouraging and will be reported separately.

Acoustics↗
PubMed1990

The geriatric auditory and vestibular systems.

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.

Aging↗
PubMed1988

Otosclerosis masking coexistent acoustic neuroma.

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.

Adult↗
PubMed1986

Relative frequency of inferior vestibular schwannoma.

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.

Cranial Nerve Neoplasms↗
PubMed1984

Acoustic reflex testing in otoneurology.

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.

Acoustic Impedance Tests↗
PubMed1984

Hearing conservation in acoustic tumor surgery: pro's and con's.

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.

Attitude to Health↗
PubMed1984

Hypoglossal-facial nerve anastomosis: a review of forty cases caused by facial nerve injuries in the posterior fossa.

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.

Adult↗
PubMed1982

Sudden hearing loss in the contralateral ear in postoperative acoustic tumor: three case reports.

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.

Adult↗
PubMed1981

The contralateral ear in acoustic tumors and hearing 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.

Amplifiers, Electronic↗
PubMed1980

The acoustic reflex latency test: clinical application.

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.

Acoustic Impedance Tests↗
PubMed1980

A workable approach to the identification of neonatal hearing impairment.

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.

Acoustic Impedance Tests↗
PubMed1979

Monothermal upright-inverted caloric test.

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.

Adolescent↗
PubMed1978

The large vestibular aqueduct syndrome.

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.

Adult↗