Biomedical subjects

D F Henry

Publications and source records attributed to D F Henry.

5 recordsLinked to original sources

PubMed1999

Test-retest reliability of open-loop bithermal caloric irrigation responses from healthy young adults.

OBJECTIVE: To determine normal caloric responses and test-retest correlations of caloric responses in a group of otologically normal persons using an open-loop caloric irrigation system. STUDY DESIGN: An open-loop bithermal caloric irrigator was used to obtain maximum slow component speed caloric responses of healthy young persons with a repeat caloric test occurring- 1 week later. SETTING: The caloric examination took place in a university speech and hearing clinic. SUBJECTS: Twenty healthy young adults (10 men and 10 women, ranging in age from 18 to 33 years) who reported no history of dizziness or hearing loss were recruited at a university. They had thresholds of 25 dB HL or better for frequencies 250 of 8000 Hz and had passed an examination performed by an otologist. RESULTS: The mean unilateral weakness (UW) response was 1.73% with a standard deviation of 12.1%. Test retest correlations were 0.82 for UW and 0.80 to 0.90 for individual ear responses. CONCLUSIONS: The results indicate that a minimum of a 25% UW should be present when identifying a significant UW. Also the test-retest correlations were considerably higher using an open-loop irrigator than those obtained using a closed-loop irrigation system in a previously reported study.

Adolescent↗

PubMed1993

Closed-loop caloric, harmonic acceleration and active head rotation tests: norms and reliability.

Norms and test-retest data from 20 persons with normal hearing and balance function were obtained for bithermal caloric (BC) using a closed-loop irrigator, sinusoidal harmonic acceleration (SHA) and active head rotation (AHR) tests. Each subject was tested twice with each test, with at least 24 hours between retest. Results of BC testing indicate that a unilateral weakness of 30% should be present to confidently identify a significant inter-ear difference when using a closed-loop irrigator for stimulus. Test-retest correlations of unilateral weakness were extremely poor, reflecting the potential for considerable variability with this test. With the exception of asymmetry measures at 0.01 and 0.02 Hz, SHA gain, phase, and asymmetry are very similar to previously published norms. Test-retest correlations were generally better than BC correlations, with phase measures having the highest test-retest correlations. AHR norms were obtained in three conditions, with eyes open and starting at a stationary target (AHR-EO), with eyes closed (AHR-EC), and with eyes open and fixated on a target moving synchronously with the head (AHR-FX). AHR-EO mean gain and phase were slightly less than that reported by other researchers, possibly as a result of differences in analysis algorithms, and had the poorest test-retest correlations. AHR-EC gain and phase were much more variable than AHR-EO between subjects, but showed very high test-retest correlations. AHR-FX gain, phase, and asymmetry are similar to those reported previously and have slightly better test-retest correlations than AHR-EO.

Adult↗

PubMed1993

Patulous eustachian tube identification using tympanometry.

The patulous, or nonclosing, eustachian tube is believed to affect as many as 7 percent of all adults, causing physical and psychological difficulties. This paper provides a brief review of the literature regarding the patulous eustachian tube (PET), its symptoms, precipitating conditions, incidence, diagnosis, and current medical management. Several case studies are also presented to illustrate the use of tympanometry in PET identification.

Acoustic Impedance Tests↗

PubMed1992

A new medication to control patulous eustachian tube disorders.

The disorder of hyperpatent eustachian tube is often unrecognized or misdiagnosed because of the ambiguous symptom of a "plugged ear." But when the patient also complains of autophony and/or hearing amphoric sounds, a patulous tube should be suspected. Persistent symptoms are distressing to most patients. This preliminary report evaluates a new nasal medication that produces closure of the tube and controls or eliminates these symptoms. It is demonstrated to be safe, predictable, and effective with little or no side effects.

Acoustic Impedance Tests↗

PubMed1985

Microscopic characteristics of genital end bulbs in the penis of bulls.

Light microscopic sections of Epon-embedded bull penis were examined for nerve endings. Tissue was taken from the dorsal midline of the glans penis and from the free portion of the penis in 6 mature bulls. Genital end bulbs were identified in both regions of the penis and were located from 1 to 500 micron beneath the epithelium, with most end bulbs concentrated next to the epithelium in the glans penis. Occasionally, end bulbs were found within nerve trunks. Other encapsulated endings were not seen. Ultrastructural correlation of the light and electron microscopic appearance of spherical end bulbs and elongated end bulbs indicated that their structure was identical. Two to 6 neurites filled with mitochondria were surrounded by several layers of thin cytoplasmic lamellae. The lamellae were characterized by pinocytotic vesicles, microtubules, and a scant basal lamina. A capsule of differing thickness enclosed the end bulbs. Fewer capsular layers surrounded more superficially located end bulbs. Near the epithelium, there were gaps in the capsule. Nonmyelinated fibers were seen within end bulbs and between end bulbs and the epithelium.

Animals↗