A posture equilibrometer for the diagnosis of vestibular disease.

Since the vestibulospinal level of vestibular function is frequently neglected in the evaluation of vertiginous patients, we developed a new posture equilibrometer for recording body swaying X (left-right) and Y (fore-aft) components of angular displacement, velocity, and acceleration with its transducer on the head of the subject. The data from patients undergoing Romberg test with eyes open and closed, Romberg test with head turned left and right and Mann test were analysed. We conclude that the equilibrometry allows one to evaluate precisely the vestibulospinal function and the sensory interaction.

[The clinical significance of analysis of frequency domain of transient-evoked otoacoustic emissions].

OBJECTIVE: To determine the clinical value of analysis of frequency domain of transient-evoked otoacoustic emissions (TEOAE). METHOD: Frequency domain of TEOAE were measured in 1. normal functional ears; 2. noise exposure ears; 3. Meniere's ears; 4. pathologic ears of media ear; 5. contralateral suppression of normal ears. RESULT: 1. After exposure to noise, the value of band signal/noise ratio were decreased in certain frequency band, main frequency of FFT response were changed in frequency spectrum. 2. In the ears of Meniere's disease, after the administration of glycerol, the value of band signal/noise ratio were increased in certain frequency band, no TEOAE were elicited before the administration of glycerol, but they appeared after glycerol administration in some ears, main frequency were changed in frequency spectrum, 3. In the pathologic ears of media ears. The value of band signal/noise ratio decreased to different extent with different kind of pathologic changes, which is related to the change of acoustic immittance. Besides. Acoustic immittance were normal in those with mild pathologic change in the tympanic membrane. The value were decreased in band signal/noise ratio. 4. After contralateral suppression of normal ears, 1 kHz and 2 kHz band signal/noise ratio value were decreased. CONCLUSION: Frequency domain of TEOAE is a sensitive parameter and has property of frequency specificity. It is of great help to study the function of outer hair cells farther and make a differential diagnose in the clinical practice.

New posture equilibrometer for the diagnosis of vestibular disease.

The vestibulospinal level of vestibular function is commonly neglected in the evaluation of vertiginous patients. We have now developed a new posture equilibrometer. A transducer is placed on the head of the subject being tested. With this meter we can record body swaying, X (left-right) and Y (fore-aft) components of angular displacement, angular velocity, and angular acceleration. A detailed analysis of the data can be made by having patients keep their eyes either open or closed during the Romberg test. The head is turned left or right in this test, while the eyes are opened and closed in the Mann test. The posture equilibrometer has enabled us to evaluate more precisely vestibulospinal function and sensory interactions.

[Effects of selective attention on distortion product otoacoustic emissions: depend on parameters].

OBJECTIVE: In order to investigate the effects of parameters of selective attention on DPOAEs. METHOD: We designed two kinds of visual tasks. One was two letters O and Q displaying on computer screen. The other was a red-blue light device. Letter Q and blue light were target stimuli flashing at random (probability was 20%), letter O and red light were non-target stimuli occurring orderly (the probability was 80%). DPOAEs with and without visual tasks were tested in 7 normal subjects (14 ears). RESULT: Both of two kinds of visual tasks suppressed DPOAEs and there was no significant difference between them (P > 0.05). Long time test and retests reduced the suppression or even made it disappear. CONCLUSION: It was suggested that parameters influence the suppressive effects. The test should not last over 1 minute and once or twice may be optical.

[The clinical value of click stimuli on the measurement of ipsilateral acoustic reflex thresholds].

OBJECTIVE: To define that click can substitute for pure tone as a stimulus to measure ipsilateral acoustic reflex thresholds, and to find out the effect of probe frequency on acoustic reflex thresholds. METHOD: Using middle ear analyzer (GSI 33, version 2), we measured 23 normal voluntary participants (46 ears) for getting the pure-tone generated ipsilateral acoustic reflex thresholds at different probe frequency and the click evoked ipsilateral acoustic reflex thresholds at click rate 100/s and 180/s for every ear. RESULT: For pure tone, the ipsilateral acoustic reflex thresholds at 500 Hz, 1000 Hz, 2000 Hz, were (84.35 +/- 6.96) dB, (84.65 +/- 5.93) dB, (87.96 +/- 6.36) dB by using 226 Hz probe; (93.13 +/- 6.54) dB, (92.70 +/- 6.33) dB, (93.35 +/- 5.99) dB by using 678 Hz probe; (86.52 +/- 4.72) dB, (87.48 +/- 5.00) dB, (88.30 +/- 6.16) dB by using 1000 Hz probe. For click, the ipsilateral acoustic reflex thresholds at click rate 100/s and 180/s were (89.78 +/- 6.83) dB, (92.07 +/- 7.42) dB by using 226 Hz probe; (90.44 +/- 6.76) dB, (90.65 +/- 6.38) dB by using 678 Hz probe; (88.04 +/- 6.87) dB, (88.69 +/- 7.42) dB by using 1000 Hz probe. The acoustic reflex thresholds for 678 Hz probe were higher than those obtained with 226 Hz and 1000 Hz probes. CONCLUSION: There were no artifact appearance while stimulus had been click at low rate, so click can be used for the measurement of ipsilateral acoustic reflex thresholds.