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Biomedical subjects

D J Orchik

Publications and source records attributed to D J Orchik.

At least 19 recordsLinked to original sources
PubMed2000

External aperture of the vestibular aqueduct in Meniere's disease.

OBJECTIVE: To study the relationship of the length of the external aperture of the vestibular aqueduct and the ratio of the summating potential and action potential (SP:AP) in patients with Meniere's disease. STUDY DESIGN: Retrospective case study. SETTING: Neurotology referral center. PATIENTS: Fifty-four patients with Meniere's disease and nine control subjects without Meniere's disease. INTERVENTION: The external aperture of the vestibular aqueduct was measured from a three-dimensional surface reconstruction computed tomography scan. Transtympanic electrocochleography was performed on patients with Meniere's disease. MAIN OUTCOME MEASURE: The length of the external aperture of the vestibular aqueduct in the Meniere's disease ears was related to the SP:AP ratio in the Meniere's disease ears and compared with controls. RESULTS: The average length of the external aperture was 3.79 +/- 2.92 mm in Meniere's disease ears and 5.35 +/- 1.73 mm in the control ears (p < 0.05). An enlarged SP:AP ratio was found in 95% of ears in the group with nonvisible external apertures of the vestibular aqueduct, 91% of ears in the <5 mm group, 58% of ears in the 5-7 mm group, and 29% of ears in the >7 mm group (chi-square = 24.814; p = 0.000). CONCLUSIONS: The length of the external aperture of the vestibular aqueduct in patients with Meniere's disease is significantly shorter than in those without Meniere's disease. Endolymphatic hydrops, evidenced by an enlarged SP:AP ratio, was related to the length of the external aperture of the vestibular aqueduct. The shorter the external aperture, the more often the SP:AP ratio was enlarged. A short or nonvisible external aperture of the vestibular aqueduct is a predisposing factor to the development of Meniere's disease.

Audiometry, Evoked Response↗
PubMed1998

Action potential latency shift by rarefaction and condensation clicks in Menière's disease.

Transtympanic electrocochleography using rarefaction and condensation clicks was performed on 122 ears of 112 patients, including 98 ears of 89 patients with Menière's disease (MD) and 24 ears of 23 patients without Menière's disease (NMD). The mean action potential (AP) latency difference between rarefaction and condensation clicks was 0.40 +/- 0.37 msec in the MD group and 0.06 +/- 0.07 msec in the NMD group (p < .01). An AP latency shift > 0.2 msec was found more often in the MD group (62.2% vs 8.3%) and in ears with an enlarged summating potential and AP ratio (69.7% vs 36.4%). The results suggest that comparison of rarefaction and condensation latencies may serve as a useful addition to electrocochleography in the diagnosis of MD.

Acoustic Stimulation↗
PubMed1998

Summating potential and action potential ratio in Meniere's disease before and after treatment.

OBJECTIVE: This study aimed to compare the summating potential and action potential ratio (SP:AP) in patients with Meniere's disease before and after various surgical and medical treatments as an indication of change in endolymphatic hydrops to study the progression of Meniere's disease. STUDY DESIGN: The study design was a retrospective case review. SETTING: The study was conducted at an otology-neurotology referral center. PATIENTS: Eighty-eight ears of 84 patients with Meniere's disease received medical treatment in 18 ears and surgical treatments including endolymphatic shunt in 12 ears, streptomycin perfusion of the lateral semicircular canal in 9 ears, streptomycin perfusion of the middle ear in 33 ears, and dexamethasone perfusion of the middle ear in 16 ears. INTERVENTION: Transtympanic electrocochleography (ECoG) was performed in all patients before treatment and 1-57 months after treatment (mean, 13.5 months) with a 2-year interval in 28 patients. MAIN OUTCOME MEASURE: An enlarged SP:AP ratio (> or = 0.40) was used as the diagnostic criterion for endolymphatic hydrops. RESULTS: Overall, an enlarged SP:AP ratio was found in 75% of ears before treatment and 78% after treatment. The SP:AP ratio, when enlarged, remained enlarged in 91% of ears. A nonenlarged SP:AP ratio before treatment became enlarged after treatment in 41% of ears. In American Academy of Otolaryngology-Head and Neck Surgery stage 1 Meniere's disease (pure-tone threshold average < or = 25 dB), an enlarged SP:AP was found in 58% of ears before treatment and 79% after. Twenty-five (89%) of 28 patients followed for 2 years were free of vestibular symptoms after treatment, and in 22 patients (79%), the SP:AP remained enlarged. The distribution of an enlarged SP:AP ratio was associated with the duration of disease (chi-square = 33.5552, p < 0.01). CONCLUSIONS: The development of endolymphatic hydrops, as indicated by an enlarged SP:AP, is part of the progression of Meniere's disease. The longer the duration of the disease, the more likely the SP:AP ratio will be enlarged. These findings indicate that endolymphatic hydrops as detected by ECoG was not reversed in this study by the treatments used. Despite the absence of definitive spells of vertigo in most patients, endolymphatic hydrops as evidenced by an enlarged SP:AP ratio persisted.

Adolescent↗
PubMed1997

Cochlear microphonics in Ménière's disease.

The pathophysiology of hearing deterioration in Ménière's disease (MD) is unclear. Hair cell loss has been proposed to be the cause of severe hearing loss in Ménière's disease. The cochlear microphonic (CM) is known to be the receptor potential of the outer hair cells in the cochlea. This study measured the CM in Ménière's disease and investigated its relationship with the degree of hearing impairment and endolymphatic hydrops. Transtympanic electrocochleography (ECoG) using rarefaction (RAR) and condensation (CON) tonebursts at 1 kHz was performed on 130 ears of 119 patients. Ninety six ears were diagnosed to have MD and 34 were diagnosed non-Ménière's disease (NMD). The mean amplitude of the CM was 33.10 +/- 46.04 microV in the MD group and 13.15 +/- 12.77 microV in the NMD group (p < 0.001). Enlarged negative summating potential and action potential ratios (SP:AP > 40%) were found in 81.3% of the MD group and 17.6% of the NMD group. In the MD group, the CM in the group with an enlarged negative SP was 36.98 +/- 49.78 microV, and 16.31 +/- 15.88 microV in the group without (p < 0.01). The CM was 34.33 +/- 49.28 microV in the pure-tone average (PTA) < or = 25 dB group, 46.97 +/- 58.31 microV in the 26-40 dB group, 29.12 +/- 42.62 microV in the 41-70 dB group, and 26.20 +/- 22.41 microV in the > 70 dB group (p > 0.05). The CMs in 11 pairs of MD ears and sensorineural hearing loss (SNHL) ears with matching hearing (MD 44 dB, SNHL 45 dB) were measured. They were 71.42 +/- 75.94 microV and 7.90 +/- 5.89 microV, respectively (p < 0.01). Our study shows that the CM is higher in ears with endolymphatic hydrops, evidenced by an enlarged SP:AP ratio, than ears without and the CM shows no statistical difference in groups with different levels of hearing loss. These findings suggest that hearing loss with a large CM in Ménière's disease patients may be the result of an alteration of cochlear mechanics and only severe hearing loss with a small CM is caused by hair cell loss. The CM measurement, to evaluate the hair cell status, may be helpful in identifying patients whose hearing may be recoverable if the underlying hydrops can be corrected. Our data do not permit the conclusion that an enlarged CM can be used in the diagnosis of MD.

Adult↗
PubMed1995

Middle ear and inner ear effects on clinical bone-conduction threshold.

The measurement of bone-conduction thresholds is an integral part of audiologic evaluation. The relationship between bone-conduction and air-conduction thresholds is the differentiating diagnostic indicator between conductive and sensorineural hearing loss. At the same time, the influence of middle ear and inner ear structures upon the bone-conduction response has been well documented. We present two cases illustrating this influence and attempt to explain the clinical bone-conduction thresholds with operative findings.

Acoustic Impedance Tests↗
PubMed1995

Traumatic endolymphatic hydrops.

Traumatic endolymphatic hydrops is an accumulation of endolymph in the cochlear duct caused by traumatic insult. The causative mechanisms are: (1) fistulization of the bony labyrinth, which causes a disturbance in the normal perilymph-endolymph pressure relationship; (2) direct injury to the membranous labyrinth, which may be just a collection of fluid in the cochlear duct from irritation, resulting in endolymphatic hydrops that may not be progressive and may subside in a short period of time after injury and hearing loss may occur; and (3) injury to the endolymphatic fluid drainage system, including a temporal bone fracture in which the fissure happens to extend through the vestibular aqueduct, causing fibro-osseous blockage of the endolymphatic duct and surgical injury to the saccule with obstruction of the longitudinal flow of endolymph, resulting in endolymphatic hydrops that may be delayed in onset and is usually persistent. The diagnosis of traumatic endolymphatic hydrops is made by a history of trauma, such as barotrauma, a blow to the head, or perhaps a previous ear operation, such as stapedectomy; the presence of typical symptoms of endolymphatic hydrops, including fullness, tinnitus, fluctuant hearing loss, and episodic vertigo; and an elevated negative summating potential and an increased summating potential:action potential ratio by electrocochleography. Three patients are presented to demonstrate this clinical entity.

Adult↗
PubMed1994

Endolymphatic hydrops associated with otosclerosis.

Endolymphatic hydrops (EH) associated with otosclerosis has been noted for many years. However, the causal relationship of these two entities remains controversial. Having reviewed the records of patients with otosclerosis describing fluctuant hearing loss and vertiginous symptoms, the authors found the EH may coexist with otosclerosis preoperatively; they may be two separate diseases that exist coincidentally; or EH may be caused by the otosclerotic process. Secondly, EH may occur with a fistula after surgery. Occurring after stapedectomy, EH may be caused by fistulization of the bony labyrinth, which is effectively treated by surgery to seal the fistula, which may cause EH to subside and hearing to improve. Thirdly, delayed EH may occur months or years after stapedectomy, possibly as a result of otosclerotic foci or surgical insult to the labyrinth. Dexamethasone, diuretics, and a room air rebreather can be used in the treatment of delayed EH. Hearing may be maintained or may deteriorate, but there usually is no dizziness. The clinical manifestations of EH associated with otosclerosis include a conductive or mixed type of hearing loss; the presence of fullness, tinnitus, fluctuation of hearing, episodic vertigo, an elevated negative summating potential (SP), and an increased summating potential:action potential (SP:AP) ratio shown by ECoG. This report presents five cases of EH associated with otosclerosis.

Adult↗
PubMed1994

Long-term results of low dose intramuscular streptomycin for Menière's disease.

The initial results of partial ablation of vestibular function are evident to control vertigo attacks and stabilize hearing as well as to reduce the severity of ataxia. The purpose of this study is to observe the long-term results of low dose intramuscular streptomycin in the treatment of bilateral Menière's disease. Eleven patients with disabling bilateral Menière's disease were treated with low doses of intramuscular streptomycin (20-40 g, mean = 25 g). Follow-up was 5-12 years (mean = 8 yr). All 11 patients achieved relief of their disabling vertigo. One patient had recurrent vertigo 1 year after treatment and streptomycin perfusion of the labyrinth was performed subsequently. Four patients reported feeling slightly off balance during follow-up. None experienced oscillopsia in this series. In the entire group of 11 patients (22 ears), hearing was unchanged in 17 ears, improved in two and worse in three. A hearing threshold of < 30 dB was found in two ears before and two after treatment; 30-60 dB was found in seven ears before and six after treatment; and > 60 dB was found in 13 ears before and 14 after treatment. The mean PTA of the 22 ears was 58 dB before and 65.5 dB after treatment. The mean speech discrimination scores were 61.4 percent before and 51.3 percent after treatment. The long-term results suggest that partial ablation of vestibular function by streptomycin has long-lasting effects of controlling vertigo attacks, stabilizing hearing, and reducing the severity of ataxia. Administration of low doses of intramuscular streptomycin is the treatment of choice for bilateral Menière's disease.

Adult↗
PubMed1993

Transtympanic electrocochleography in Menière's disease using clicks and tone-bursts.

Transtympanic electrocochleography (ECoG), using clicks and tone-bursts at 500, 1000, and 2000 Hz, was employed to study 80 patients with Meniere's disease and 25 non-Meniere's patients. The magnitude of the negative summating potential and the summating potential:action potential ratio (SP:AP) were examined in both groups. Groups were further divided based upon degree of hearing loss and audiometric configuration. An elevated SP:AP ratio was found in 83.7 percent of the Meniere's ears and 12 percent of the non-Meniere's. The likelihood of obtaining a positive ECoG in Meniere's patients was strongly related to degree of hearing loss but not audiometric configuration.

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

Computer generated probe-microphone measurements in hearing aid selection.

Verification of hearing aid performance through probe-microphone measurements has gained considerable popularity in recent years. This paper presents the basic concepts and terminology in computer generated probe-microphone measurements and reviews the clinical applications of this technology.

Computers↗
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↗
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

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

Intensity and frequency of sound levels from cordless telephones. A pediatric alert.

Recent reports have established that the ring of a cordless telephone is sufficient to produce hearing loss. In the present study, the intensity and frequency spectrum of the ring signal for three cordless telephones known to be involved in reported cases of acoustic trauma are presented. The potential hazard to hearing is reviewed, the implications for the pediatric community discussed, and the recommendation made that unmodified cordless telephones be kept out of the reach of children.

Acoustics↗