Biomedical subjects

B L Fetterman

Publications and source records attributed to B L Fetterman.

10 recordsLinked to original sources

PubMed2001

Distortion-product otoacoustic emissions and cochlear microphonics: relationships in patients with and without endolymphatic hydrops.

OBJECTIVES: Because endolymphatic hydrops causes cochlear malfunction, and both otoacoustic emissions and cochlear microphonics measure specific cochlear activities, some insight into the pathology of Meniere's disease might be gained by using these two test modalities. Specifically, the involvement of cochlear outer hair cells in patients with endolymphatic hydrops may be detected. Furthermore, it is hoped that these two tests might help determine which regions of the cochlea are affected by endolymphatic hydrops, as well as where along the auditory pathway abnormalities are present. STUDY DESIGN: Data were gathered prospectively on patients presenting to a private, tertiary referral otology/neurotology practice. METHODS: From February 1999 to April 2000, clinical information was collected on patients presenting with vertigo, hearing loss (HL), sudden HL, fluctuant HL, aural fullness, and/or tinnitus. Data included demographics, diagnosis, pure-tone and speech audiometry, tympanometry, summating potential, action potential, cochlear microphonic, and distortion-product otoacoustic emissions. Descriptive statistics were calculated, and relationships between distortion-product otoacoustic emissions and cochlear microphonics in patients with hydrops (defined as summating potential to action potential ratio > or =0.40) and without hydrops were analyzed. RESULTS: Distortion-product otoacoustic emissions were present more often and had larger amplitudes at the lower frequencies. No differences were found in the presence of distortion-product otoacoustic emissions across the frequencies for the two groups, but larger mean amplitudes were found for hydropic ears at 7966 Hz. As hearing levels worsened, both hydropic and nonhydropic ears were less likely to have emissions present; however, 18% of hydropic ears had emissions unexpectedly present when the pure-tone thresholds were > or =50 dB. The cochlear microphonic from the hydrops group tended to be smaller, but this was not statistically significant. Analysis of variance showed a small negative correlation between summating potential to action potential ratio and level of emission at 1968 Hz in hydropic ears; otherwise, there was no relationship between the ratio and emissions. The only statistically significant finding when analyzing the relationship between cochlear microphonic and otoacoustic emission was a small positive correlation between level of microphonic and level of emission at 1406 Hz in hydropic ears. No significant relationships were found between hearing thresholds and emissions or microphonics. CONCLUSIONS: Even though both distortion-product otoacoustic emissions (DPOAEs) and cochlear microphonics (CMs) measure specific cochlear activities, they were not found to be useful for differentiating patients with hydrops from those without. In some patients, however, unexpected distortion-product otoacoustic emissions were present. This may represent localizing information about which regions of the cochlea are being affected by hydrops in these patients. Also, a small positive correlation between the CM and the DPOAE at 1406 Hz was detected in the hydrops group, which may represent the effects of endolymphatic hydrops on the outer hair cell. Future investigations involving hydropic patients with unexpected DPOAEs and studies looking for more DPOAE and CM correlations at frequencies surrounding 1406 Hz are being planned.

Adult↗

PubMed1997

Relief of headache by cranioplasty after skull base surgery.

Headache after skull base surgery can cause profound morbidity in certain patients, resulting in significant impairment of their quality of life. Several methods to prevent postoperative headache have been described, including a modification of the skin/muscle incision replacing the craniotomy bone flap replacing the bone flap and filling in the residual defect with methyl methacrylate, using hydroxyapatite cement (HAC) to fill the craniectomy defect, and wiring hardened methyl methacrylate (MMA) into the defect. Ten patients with severe headache following craniectomy for a posterior fossa lesion underwent cranioplasty with MMA, which was placed exactly within the craniectomy defect and secured rigidly with miniplates and screws. The headache decreased in severity in all patients and resolved completely in 90%. Also, 78% of patients with dizziness improved. The procedure and its effect on headache and dizziness will be described.

Journal Article↗

PubMed1997

Management of external penetrating injuries into the hypopharyngeal-cervical esophageal funnel.

OBJECTIVE: To compare outcomes related to observation versus exploration for the hypopharynx and the cervical esophagus as the site of proven external penetrating injuries. METHODS: The records of 70 patients (47 with hypopharyngeal and 23 with cervical esophageal wounds) were retrospectively reviewed. RESULTS: No patient, observed or explored, who sustained a penetration into the hypopharynx above the level of the tips of the arytenoid cartilages of the larynx developed a complication. However, 22% of the patients with a hypopharyngeal injury below this level and 39% of patients with a cervical esophageal injury developed either a deep neck infection that required drainage or a postsurgical salivary fistula. CONCLUSIONS: Overall, the consequences of an external penetrating injury become more serious in the descending levels of the funnel formed by the hypopharynx and cervical esophagus. Injuries located in the upper portion of the hypopharynx can be routinely managed without surgical intervention. Neck exploration and adequate drainage of the deep neck spaces are, however, mandatory for all penetrating injuries into the cervical esophagus and most injuries into the lower portion of the hypopharynx.

Adolescent↗

PubMed1997

The rehabilitation of conductive hearing impairment.

Conductive hearing loss (CHL) usually is amenable to surgical correction. At times, patients with CHL may not be candidates for surgical correction, or they may refuse to undergo the procedure. In such a situation, the patient should be encouraged to try hearing aids, either conventional or bone conduction, depending on the pathologic condition. After a discussion of bone-conduction implantable hearing aids, the article discusses congenital aural atresia, otosclerosis, and the management of CHL after infratemporal fossa approach and transtemporal approaches.

Bioprosthesis↗

PubMed1996

Sudden bilateral sensorineural hearing loss.

Most cases of sudden sensorineural hearing loss (SHL) remain idiopathic, and the majority are unilateral. From 1989 to 1993, 823 patients with sudden SHL were evaluated. Of these, 14 (1.7%) had sudden bilateral SHL. We reviewed the charts of these 14 patients to compare sudden bilateral SHL with sudden unilateral SHL. Usually, bilateral SHL was asymmetric. Most bilateral cases received combined steroid and vasodilator treatment, while unilateral cases were more likely to receive only one of these treatments. By audiological criteria, 67% of bilateral SHL cases improved, while the improvement rate in unilateral SHL was 52%; however, this difference was not statistically significant. In bilateral SHL patients showing improvement, both ears responded. Bilateral SHL patients were older at the onset of hearing loss, had a higher incidence of vascular disease, and were more likely to have positive antinuclear antibody titer. Recognition of similarities and differences between sudden unilateral and bilateral SHL can help in counseling patients.

Case-Control Studies↗

PubMed1996

Prognosis and treatment of sudden sensorineural hearing loss.

Most cases of sudden sensorineural hearing loss (SHL) are idiopathic. Consequently, the otologist may be asked to predict hearing recovery and select a treatment strategy without fully understanding the disease process. We retrospectively reviewed the charts of 837 patients with SHL to evaluate the prognostic value of specific clinical parameters and the effectiveness of steroid and vasodilator treatments. Treatment response was defined by the patient's subjective response and audiological criteria. Patients who were treated with steroids and/or vasodilators were more likely to improve. Patients who improved had a worse initial pure-tone average (PTA) than those who did not improve. In addition, those with poorer initial speech discrimination scores, worse initial thresholds at 4,000 Hz, younger age, and greater number of treatments were more likely to improve. Neither the electronystagmogram results nor the initial audiogram shape were valuable indicators. Recognition of prognostic indicators can help in counselling patients and in the evaluation of treatment response.

Adrenal Cortex Hormones↗

PubMed1995

Sudden hearing loss in acoustic neuroma patients.

Patients with acoustic neuroma may have sudden sensorineural hearing loss. Most patients with sudden hearing loss seek medical attention promptly, but the diagnosis of an acoustic neuroma may be delayed for months or years because sudden hearing loss is an unusual initial symptom of an acoustic neuroma. In a retrospective review of 836 cases of sudden hearing loss, we found 13 patients with acoustic neuromas. The prevalence of acoustic neuromas for those screened with auditory brain stem response or magnetic resonance imaging was 2.5%. In addition to these 13 patients, 79 acoustic neuroma patients treated in our clinic had well-documented sudden hearing loss as the initial symptom. Hearing loss in these 92 patients ranged from mild to profound. Associated symptoms of pain, facial paresthesia, or unilateral tinnitus preceding the sudden hearing loss were suggestive of an acoustic neuroma, as was a midfrequency (U-shaped) hearing loss. A history of other diseases or events that might explain the sudden hearing loss, a normal electronystagmogram, or recovery of hearing does not eliminate the possibility of a tumor. Because there are no clinical findings that clearly distinguish those patients with acoustic neuromas from other patients with sudden hearing loss, we recommend either an evaluation with auditory brain stem response or gadolinium-enhanced magnetic resonance imaging for any patient with sudden hearing loss.

Adult↗

PubMed1995

Gunshot wounds of the temporal bone: a rational approach to evaluation and management.

Gunshot injuries of the temporal bone are uncommon but are being seen more frequently with the increasing incidence of violent crimes and use of firearms. A retrospective analysis of 43 consecutive patients treated at our institution with this injury was undertaken to determine the clinical symptoms, associated injuries, and treatment outcome. This is the largest series from a single institution treated by a single group during a brief period of time. Most of these patients had injury to various structures within and around the temporal bone, including hearing loss (29), intracranial injury (23), facial nerve injury (22), vascular injury (14), and mandible fracture (6). Ocular trauma and paralysis of cranial nerves V and IX, X, XI, and XII were rare occurrences. A rational approach to the evaluation and management of these injuries will be discussed in detail to optimize outcome.

Adolescent↗

PubMed1995

Management of traumatic hypopharyngeal injuries.

Violation of the hypopharynx by external penetrating trauma is an uncommon occurrence that may lead to life-threatening infectious complications if not recognized promptly and treated appropriately. A retrospective review of 48 such injuries seen during a 10-year period showed that flexible fiberoptic endoscopic examination is the best screening tool for recognition of a possible hypopharyngeal mucosal violation. Direct laryngopharyngoscopy is the best method of definitively diagnosing the injury. Size of the visualized mucosal violation alone is not sufficient information on which to base the decision for medical management versus surgical intervention (i.e., immediate exploration and drainage). Rather, the size, exact site of injury, and mechanism of the injury must be considered to have equal importance. Associated vertebral body fractures may negatively influence acute outcome if diagnosis and treatment of the hypopharyngeal injury are delayed by the cervical spine injury.

Adolescent↗

PubMed1994

Metabolic influences on satiety in rats receiving parenteral nutrition.

Food intake is reduced during parenteral nutrition (PN) proportionally to the amount of calories or composition of the solution infused. The relative importance of infused glucose and lipid, 50 and 30% of PN kilocalories, respectively, in reducing food intake during PN was examined. Glycolysis, fatty acid oxidation, or both were acutely disrupted with 2-deoxy-D-glucose (2-DG) and mercaptoacetate (MA). Rats receiving intravenous infusions of saline or a PN solution providing 100% of total daily calories (PN-100) received a single intraperitoneal injection of saline, 2-DG, and/or MA during the early light phase. 2-DG (1.4 or 2.2 mmol/kg) did not initiate feeding in PN-100 rats, although hyperglycemia was evident in all rats 1 h after 2-DG. Food intake of PN-100 rats after MA (0.4 mmol/kg) was approximately 50% that of control rats. When 2-DG (1.4 mmol/kg) and MA (0.4 mmol/kg) were administered concomitantly, PN-100 and control rats consumed the same amount of food. During PN-100, rats appeared to be more sensitive to losing metabolic energy derived from lipid than from glucose.

Animals↗