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Biomedical subjects

J J Shea

Publications and source records attributed to J J Shea.

At least 55 records · Page 3Linked to original sources
PubMed1990

Endolymph pressure in Menière's disease.

During the streptomycin perfusion/shunt of the lateral semicircular duct operation for Meniere's disease, the lateral semicircular duct is exposed by removal of the bone of the lateral semicircular canal. Before perfusion with streptomycin and creation of a shunt in the lateral semicircular duct, the pressure in the lateral semicircular duct is measured while electrocochleography is being recorded. In most ears with Meniere's disease, the pressure necessary to indent the lateral semicircular duct is 2 to 3 mm of water. The pressure is more in those ears with a large negative summating potential than in those with a normal negative summating potential. The pressure is less after the shunt in the lateral semicircular duct is created and the negative summating potential returns to normal. In some ears with the classic picture of Meniere's disease, the endolymph pressure is normal and there is a normal negative summating potential. Presumably, one should not create a shunt in the lateral semicircular duct in ears with normal pressure.

Audiometry, Evoked Response↗
PubMed1990

Speech recognition ability as a function of duration of deafness in multichannel cochlear implant patients.

Surgical implantation of a multichannel cochlear prosthesis has become a widespread treatment for profound hearing loss. The relationship between duration of hearing loss and speech recognition ability was examined in 20 postlinguistically deafened adults using the Nucleus 22-Channel Cochlear Prosthesis. Data analysis indicated statistically significant negative correlations between duration of profound hearing loss and postoperative performance on the Central Institute for the Deaf Everyday Sentence Test and the Northwestern University Monosyllabic Word Test (NU-6). Age at implantation and age at onset of profound hearing loss were not found to be significantly correlated with performance on the two measures. These findings are discussed in terms of patient counseling and prediction of potential benefit to the patient.

Adult↗
PubMed1990

Selective chemical vestibulectomy.

In an attempt to destroy selectively the affected peripheral vestibular labyrinth in patients with intractable vertigo as a result of Meniere's disease, a known quantity of streptomycin was introduced within the bony labyrinth following fenestration of the horizontal semicircular canal. Initial laboratory results in animal models proved that near total ablation of the vestibular end-organs (including the hair cell population of the cristae ampularis, utricle, and to some extent the saccule) could be achieved chemically without involvement of the cochlear hair cell population. The exact dose required to accomplish this in the animal model was 250 micrograms of streptomycin. However, this dose proved excessive in initial human application possibly because the animals had excellent hearing in nondiseased ears while our patients uniformly had long standing inner ear disease with marked decrease in auditory thresholds. The current dose of streptomycin utilized is 125 micrograms, and patients treated thus far have maintained (or improved) their preoperative audiologic pure tone average. The aim of this preliminary report is to detail our developmental animal research and subsequent clinical application of selective chemical vestibulectomy (SCV) in 15 patients with intractable vertigo as a result of Meniere's disease, which have failed conventional medical management.

Adolescent↗
PubMed1989

Perfusion of the inner ear with streptomycin.

Any medical or surgical treatment of Meniere's disease is always suspect because the natural history is so variable and the pathologic physiology is not well-known. Even the occurrence rate in one and both ears is not known. It is certainly true that endolymphatic hydrops, caused by the failure of absorption of endolymph in the endolymphatic sac, is the principal pathology in the classical, fully developed Meniere's disease. While the endolymphatic shunt operation is correct in theory, in most ears, it does not work because the surgeon does not always locate the lumen of the sac and when located, the shunt tube does not remain open. While vestibular neurectomy is more likely to give permanent relief of vertigo as compared to the endolymphatic sac operation, the operation is difficult and dangerous and does nothing for the hearing. The vestibulotoxic action of the aminoglycocide antibiotics, especially streptomycin, when introduced into the perilymph of the lateral semicircular canal will destroy the vestibular receptors without making the hearing worse, and by acting on the dark cells, reduce the production of endolymph. Perfusion of the perilymph with streptomycin through an opening in the bony lateral semicircular canal is the operation of choice for Meniere's disease, benign paroxysmal postural vertigo and other forms of vertigo. So far 66 such operations have been done during the last three years with very encouraging results.

Aged↗
PubMed1988

Thirty years of stapes surgery.

The modern stapedectomy with prosthesis insertion and living oval window seal, like the modern cataract extraction with lens replacement, is now performed, very much the same, throughout the world. I have reviewed the evolution of stapes surgery during these last thirty years and tried to gain some agreement for several important facts about otosclerosis and several basic principals of stapes surgery. While a well-performed stapedectomy can eliminate the conductive component, the sensorineural hearing loss continues and, in about one-third, will progress till the patient, after age 65, must return to a hearing aid. A piston prosthesis gives the best hearing results: 0.6 mm diameter, when half the footplate is removed and a living oval window seal interposed, and 0.6 mm diameter when a small opening is made in the footplate obliterated by otosclerosis. I prefer a teflon prosthesis to stainless steel because it can be altered by the surgeon at operation, and vein as an oval window seal. I have presented a rare group of patients who develop facial palsy 5-1/2 days after uncomplicated stapedectomy, of whom all recover quickly and completely. I am confident that progress will continue to be made in the understanding of otosclerosis, and the performance of stapes surgery, but in these last thirty years we have made a good beginning.

Aged↗
PubMed1987

Sensorineural hearing loss in cordless telephone injury.

Audiometric data from 19 cases of cordless telephone injury are reviewed, including three cases with pre-insult and post-insult audiograms. In addition, data are presented from analyses of intensity and frequency for the ring signal of three telephones involved in injury cases. The most severe hearing loss was found at 500 Hz and 1000 Hz, where the mean threshold difference in the injured ear was 20 dB and 29 dB, respectively. The three cases for which pre-insult and post-insult data were available exhibited similar audiometric patterns, although the degree of threshold shift varied. Spectral analysis of the ring signal indicated sound-pressure levels of approximately 140 dB, with a fundamental frequency near 750 Hz.

Audiometry↗
PubMed1987

Streptomycin treatment in Menière's disease.

Streptomycin treatment in Menière's disease has traditionally been used for control of vertigo in patients with severe bilateral involvement or unilateral involvement in the only hearing ear. Guidelines for use that have worked at the Shea Clinic are presented. In addition, a special case is discussed in which this form of therapy has been used for treatment of fluctuant hearing loss in a patient with Menière's disease.

Aged↗
PubMed1987

Multiple sclerosis manifesting as sudden hearing loss.

We have presented a unique case in which sudden sensorineural hearing loss was the only initial symptom that developed in a patient who later displayed further symptoms consistent with multiple sclerosis. Although an uncommon cause of sudden hearing loss, multiple sclerosis should be suspected in patients whose symptoms are resistant to routine treatment modalities and in whom other (seemingly incongruous) cranial neuropathies develop.

Adult↗
PubMed1987

Stapedectomy and round window closure.

Round window closure is an uncommon complication of advanced otosclerosis found in 1% of 30,000 stapedectomy cases. A review of 81 patients representing 110 operation cases was made to determine what factors may alert the otologic surgeon to the patient with round window closure and what factors may identify the patient who will achieve the greatest benefit from stapedectomy.

Adult↗
PubMed1986

Electrocochleography and low-frequency harmonic acceleration in Meniere's disease.

We evaluated a series of 31 consecutive cases of Meniere's disease using electrocochleography (ECochG) and low-frequency harmonic acceleration (HA). The ECochG was positive for endolymphatic hydrops in 74% of the cases. A positive ECochG was strongly related to the degree of hearing loss. The results of harmonic acceleration were consistent with peripheral vestibular disorder in 80% of the cases. Five illustrative cases are also presented.

Adult↗
PubMed1986

Nonsurgical management of small and intracanalicular acoustic tumors.

It is generally accepted that the proper treatment for acoustic tumors is surgical removal. In fact, there is little, if any, reference to nonsurgical treatment of these tumors in the recent medical literature. We would like to report on the nonsurgical management of six patients with cerebellopontine angle tumors based upon CT examination. The diagnostic findings, follow-up data, and the rationale upon which the decision was made to treat the patients nonsurgically will be presented, as will a review of the pertinent literature.

Aged↗
PubMed1986

Long-term experience with biocompatible ossicular implants.

The senior author's 8-year personal experience with biocompatible ossicular implants is reviewed. Four hundred sixty-one consecutive operations, in which high-density polyethylene sponge ossicular replacement prostheses were used, are grouped according to the Bellucci classification of chronic otitis media. The prostheses used were the drum-to-footplate prosthesis (TORP, total) and the drum-to-stapes prosthesis (PORP, partial). Each group's short- and long-term hearing results are compared. Prosthesis extrusion and persistent or recurrent conductive hearing loss are the most common causes of operation failure. Failures within each group are analyzed, and techniques to prevent these complications are outlined.

Biocompatible Materials↗
PubMed1986

A simple autologous fibrinogen glue for otologic surgery.

A simple method of concentrating a patient's own fibrinogen for use with a thrombin/calcium solution--to produce a coagulum-type tissue glue for otologic surgery--is presented. The principal advantages of this system include a simple modification of the cryoprecipitate technique, which can be easily performed in any hospital laboratory using a minimal amount of the patient's blood, and the use of autologous fibrinogen, which completely rules out the possibility of transmission of hepatitis or AIDS viruses. Useful tips on preparation and use of this autologous tissue glue, based on experience over the past 2 years, will be presented.

Aprotinin↗
PubMed1986

Low-frequency harmonic acceleration in the evaluation of patients with intracanalicular and cerebellopontine angle tumors.

The application of low-frequency harmonic acceleration (HA) with the rotary chair is becoming more widespread in the clinical evaluation of the vestibular system. In the last 2 years, 18 patients with surgically or radiologically confirmed intracanalicular or cerebellopontine angle tumors have been evaluated with this clinical modality. In all cases (100%)--which included seven small tumors--vestibular evaluation with HA was abnormal. Slow harmonic acceleration, as is the case with other methods of vestibular evaluation, is not specific for acoustic tumors. Its great sensitivity in detecting peripheral vestibular abnormalities, however, may make it a useful addition to the test battery in the evaluation of patients with suspected intracanalicular or cerebellopontine angle tumors.

Acceleration↗
PubMed1985

Endolymphatic hydrops in guinea pigs after cauterizing the sac with silver nitrate.

There have been several reports of perisaccular fibrosis of the endolymphatic sac in some autopsied cases of Meniere's disease. We attempted to initiate perisaccular fibrosis of the sac in guinea pigs by injecting a small amount of 10% silver nitrate solution that cauterizes the tissue readily to produce scar, ie, fibrosis. Ninety-nine guinea pigs out of 108 (92%) that were treated with silver nitrate showed the endolymphatic hydrops in varied extent, from slight to profound. The extent of hydrops might depend on the extent of destruction of the sac following the cauterization. The lumen of the sac was sometimes occupied with dense fibrous connective tissue with deposition of black-silver particles in it. The silver nitrate injection method is an easy way to produce endolymphatic hydrops in guinea pigs.

Animals↗
PubMed1985

Auditory evoked potential alterations induced by pulsed ultrasound.

Diagnostic levels of pulsed ultrasound were applied abdominally over the uteri of pregnant rats for five minutes daily during the first 20 days of gestation. The average energy output of the ultrasound machine at the optimum focal length of the transducer (5.4 cm) was 7.2 mW/sq cm. Postnatal auditory evoked potentials demonstrated a significant alteration in the offspring of the treated animals when compared with similarly treated, but nonexposed controls. This alteration only occurred in the high frequency range. Neither light nor electron microscopy revealed significant morphologic alterations in the cochlear elements of the exposed offspring. Although a cochlear deficit occurred in a range known to be important to the rat's hearing, several issues make this data reassuring to clinicians using diagnostic levels of pulsed ultrasound: the total amount of ultrasound exposure was higher than would be expected with human use, the defect was mild, and the absence of clear-cut morphologic abnormalities may indicate the presence of a minimal, or even reversible, defect.

Acoustic Stimulation↗