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Volume 97, Issue 4
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SHINJI KITANI1994 Volume 97 Issue 4 Pages 645-653
Published: 1994
Released on J-STAGE: March 19, 2008
JOURNAL FREE ACCESSAntidromic evoked potentials (AEPs) of the facial nerve were registered from the external auditory canal (EAC) of guinea pigs to clarify the origin of AEP and to compare diagnostic values of AEP with those of conventional evoked electromyography (eEMG).
1) The latency of AEP registered from EAC was compared with those from three points along the fallopian canal. The results showed that the latency from the pyramidal portion was almost equal to that from EAC.
2) AEPs were registered from EAC following sectioning of the intratemporal portion of the facial nerve at five points between the geniculate ganglion and the stylomastoid foramen. The waveform of the AEP was biphasic when the nerve was cut proximal to the pyramidal portion. It was monophasic when sectioned peripheral to that portion. These results, together with findings from experiment 1, indicate that AEP reflects the evoked potential generated around the pyramidal portion of the facial nerve, and that AEP is useful for the topodiagnosis of facial palsy.
3) AEP and eEMG were registered to assess changes in elicitability following compression of the facial nerve. Disappearance and reappearance of the AEP reflected well the function of the facial nerve as compared to the eEMG. This also indicates that AEP is a potentially sensitive and reliable diagnostic parameter for predicting the prognosis of facial palsy.
4) Registration of AEPs was attempted in three normal human subjects and in seven patients with Bell's palsy. AEP were recordable in all three normal men. Recording was however, possible in only two of seven patients on the involved side. In one patient, AEP was evoked on the third disease day, and in the other on the 38th day when the palsy had completely disappeared. Clinical application of AEP would, as yet, be premature and problems remaining to be solved are discussed herein.View full abstractDownload PDF (757K) -
JUNICHI MATSUSHIMA, MASAHIKO KUMAGAI, KUNIHIRO TAKAHASHI, SHIGEKI MIYO ...1994 Volume 97 Issue 4 Pages 654-660
Published: 1994
Released on J-STAGE: March 19, 2008
JOURNAL FREE ACCESSThe purpose of this study was to introduce the electroconduction system for an implantable tinnitus suppressor. This system is a modification of the extracochlear implant system, which was developed at Hokkaido University. This system consists of a stimulator and two coils. One of the coils is implanted inside the temporal bone and its size, including the current limiter, is 9mm long, 6. 4mm wide and 6mm thick. Another is contained in the plastic case which is used for hearing aids. The efficacy of conduction depends on the wave frequency. The most effective frequency was about 30kHz. The maximum current required to relieve tinnitus is 100μA when using this system. The heat emitted from the coil inside the case is so minimal at an intensity of 100μA as to be negligible systemlcally, The electromagnetic coupling system works well for more than 4 months in saline.View full abstractDownload PDF (1587K) -
JUNICHI MATSUSHIMA, MASAHIKO KUMAGAI, KUNIHIRO TAKAHASHI, NOBORU SAKAI ...1994 Volume 97 Issue 4 Pages 661-667
Published: 1994
Released on J-STAGE: March 19, 2008
JOURNAL FREE ACCESSInstitute of Electrical Science, Hokkaido University, Sapporo An electrical tinnitus suppressor, which was developed at Hokkaido University, was implanted in a female tinnitus patient. She had suffered from bilateral chronic otitis media and her bilateral hearing was seriously impaired. The electrical tinnitus suppressor consists of a stimulator, a coil inside the plastic hearing aid case and an implanted coil in the mastoid. The auditory nerve is stimulated at home twice. Using the system, her hearing ability and emotion improved in addition to tinnitus suppression. Her hearing level and tinnitus also improved in the ear contralateral to the stimulated side.View full abstractDownload PDF (1571K) -
EUSTACHIAN TUBAL FUNCTION OF NORMAL EARSTAKASHI YAMAGUCHI1994 Volume 97 Issue 4 Pages 668-673
Published: 1994
Released on J-STAGE: March 19, 2008
JOURNAL FREE ACCESSEustachian tubal function was evaluated in two age groups: children aged 4 to 14 years and adults aged 23 to 74 years. The test group of children included 224 normal ears, the test group of adults 106 normal ears. Active opening function was determined by sonotubometric eustachian tubal function testing, which measures the duration of patency of the eustachian tube during swallowing. Passive opening function was determined by tubo-tympanoaerodynamic graphy (TTAG), which measures the naso-pharyngeus pressure when tubal opening is produced by the Valsalva maneuber.
1) The duration of patency of the Eustachian tube during swallowing in children was increased from the age of 8 and was nearly equal to the adult value at the age of 11. As the children got older, the naso-pharyngeus pressure when tubal opening is produced by the Valsalva maneuver increased and was nearly the same as the adult value at the age of 10. From the above, it seems that the pressure opening type Eustachian tubal function in children changes to the muscular opening type tubal function in adults at the age of 10 or 11.
2) The duration of patency of the Eustachian tube during swallowing was shorter in the group older than 60 years. The Valsalva maneuver was higher in the group above age of 50 than in younger adults. These characteristics of the Eustachian tubes of older age groups may be among the causes of adult type serous otitis media, which often occurs in older adults.View full abstractDownload PDF (452K) -
EXPRESSION OF OSTEOPONTINMASAFUMI SAKAGAMI, TEIJI TAKEMURA, MASANORI UMEMOTO, TAKESHI KUBO1994 Volume 97 Issue 4 Pages 674-679
Published: 1994
Released on J-STAGE: March 19, 2008
JOURNAL FREE ACCESSOsteopontin (OPN) is considered to be a non-collagenous bone matrix protein which is involved in the ossification process. However, OPN has recently been observed in ectopic sites such as the kidney and nervous tissues.
In the present study, expression of OPN mRNA was examined in the rat inner ear by nonradioisotopic in situ hybridization. Signals of OPN mRNA were observed in the marginal cells of the stria vascularis, spiral ganglions, vestibular sensory hair cells and vestibular dark cells. OPN protein was detected only in otoliths by immunohistochemistry. The reasons for the presence of OPN mRNA in the cochlea and dark cells of the vestibulum were unclear. On the other hand, findings of the sacculus and utriculus suggest that OPN is one of the protein components of rat otoliths and that vestibular sensory hair cells are involved in the production of otoliths.View full abstractDownload PDF (1333K) -
MASAFUMI YOSHIDA, MITSUYOSHI AOYAGI, KAZUMI MAKISHIMA1994 Volume 97 Issue 4 Pages 680-683
Published: 1994
Released on J-STAGE: March 19, 2008
JOURNAL FREE ACCESSThe cochlear microphonics (CM) response to two-tone stimuli was measured before and after exposure to 4kHz pure tone at 100dB SPL or 125dB SPL. The 2f1-f2 distortion products in the CM (CM-DPs) were markedly suppressed by the sound exposure at either intensity, although the loss of CM output at the primary frequencies was limited to 4dB or less. The suppression of CM-DPs was greater as the intensity of primary tones decreased, especially at primary intensities below 55dB. These results show that the active transduction process in the cochlea was affected by acoustic overstimulation. This impairment of active transduction was postulated to be an initial process in developing noise induced temporary and/or permanent threshold shift.View full abstractDownload PDF (347K) -
NORIYUKI SAKIHAMA1994 Volume 97 Issue 4 Pages 684-687
Published: 1994
Released on J-STAGE: March 19, 2008
JOURNAL FREE ACCESSRecently, it has been reported that the facial nerve in the facial canal shows enhancement on gadolinium-enhanced magnetic resonance imaging (Gd-MRI) in patients with a clinically normal facial nerve. Enhancement is also observed in the Gasserian ganglion and in the second and third divisions of the trigeminal nerve at the base of the skull.
The aim of the present investigation was to study the vascular permeability of cranial nerve roots using the tracer technique.
Vascular permeability in the cranial nerve root was examined after intravenous injection of sodium fluorescein (FluoreciteR) as a tracer, in the rabbit. Fluorescence was observed in the distal nerves through the following portions: intracavernous portion of the third, distal internal auditory canal segment of the seventh, and ganglionic portions of the fifth, ninth and tenth cranial nerves. No fluorescence was observed in the first, second or eighth cranial nerves. The fluorescence of the other cranial nerves was undetectable because of a slender fasciculus.
Histologically, fluorescence was observed in the external nerve sheaths (epineurium and perineurium) and the endoneurium of the cranial nerves showing fluorescence. No fluorescence was observed within the nerve fibers. In the ganglia, fluorescence was also seen in ganglion cells and intercellular connective tissues.
Since Fluorecite (mol. wt. 376 and a negative charge) was dispersed in the cranial nerves, it is feasible that Gd-DTPA (mol. wt. 742 and negative charge) may also be distributed in these portions. This distribution may indeed provide an insight into the Gd-MRI enhancement observed in facial and trigeminal nerves.View full abstractDownload PDF (1570K) -
MASAYUKI SAWAKI, TAKU HATTORI1994 Volume 97 Issue 4 Pages 688-695
Published: 1994
Released on J-STAGE: March 19, 2008
JOURNAL FREE ACCESSTo explore the mechanisms of cochlear regulation systems, two tone phenomena of transiently evoked otoacoustic emissions (EOAEs) were measured using a forward masking paradigm in normal human ears. EOAEs were elicited by probe tone (1 kHz, 25 dBnHL, 3ms duration), with or without a preceding masker tone (841Hz, 35-85 dBnHL, 10-300ms duration, 5-160ms interval). In the intensity study, EOAEs showed decrements in amplitude according to the masker intensity. To evaluate the effects of the stapedial reflex (SR), the forward masking in facial palsy cases without SR was also measured. For the higher intensity masker, SR effects were observed in normal cases. The duration study showed a little but almost constant decrement with lower intensities, below the SR threshold, and a 20ms or more duration masker. The interval study showed the decrement even with low and middle (35/55 dBnHL) intensity masker when the intervals were short. As the intervals were shortened, the decrement in EOAEs amplitude became greater. These results suggest that not only the olivocochlear bundle but also other mechanisms, e. g. short-term adaptation and/or lateral inhibition, may affect the forward masking of EOAEs.View full abstractDownload PDF (616K) -
YOSHIYUKI KITAOKU, TOSHIHIRO YAMAMOTO, KAZUHIKO NARIO, TAKASHI MATSUNA ...1994 Volume 97 Issue 4 Pages 696-702
Published: 1994
Released on J-STAGE: March 19, 2008
JOURNAL FREE ACCESSContingent negative variation (CNV) was elicited using electrical taste stimulation as the warning stimulus. Stimuli were generated for 100 msec or 500 msec using a bipolar stainless steel electrode disc with the center portion acting as the anode and the outer portion as the cathode. The imperative stimulus was a pure tone of 1 kHz at 60 dB and the interstimulus interval of paired stimuli was 2000 msec. The electrode was gently held in contact with the tongue by a specially made fixture and electrical taste stimuli were presented at 5-sec intervals. The CNV was recorded in 10 normal subjects at the Cz site of the 10-20 International System, referred to linked earlobes with a forehead ground. The results from 20 presentations were averaged.
The mean threshold measured by electrogustometry employing a monopolar electrode as the anode was-4.2dB (0dB=8μA), and the mean thresholds measured with the bipolar electrode at a stimulus duration of 100 msec and 500 msec were 0dB and -1.4dB, respectively. As the mean threshold obtained with a duration of 500 msec was closer to the electrogustometry findings than that obtained with a duration of 100 msec, a stimulus duration of 500 msec was useful for determining the CNV threshold.
The CNV could be recorded in all 1O normal subjects, and the late component was conspicuous because of recording at the Cz site. In four subjects, the P300 could be recorded after the warning stimulus at an intensity of 40μA. Clear P300 waveforms were obtained after warning stimuli with a duration of 100 msec, but the P300 waveforms obtained with a stimulus duration of 500 msec were wide and the bounds of the P300 and the CNV were unclear. As it was necessary to maintain the concentration of the subjects during CNV recording, we had to shorten the test period, but we could still approximately determine the CNV thresholds corresponding to the electrogustometry thresholds.
In conclusion, it was possible to evaluate the electrical taste threshold objectively from the CNV and the P300 elicited by electrical taste stimulation.View full abstractDownload PDF (1108K) -
PRELIMINARY STUDY ON THE FROG WITH VESTIBULAR NEURECTOMYTAKUO IKEDA, TORU SEKITANI, TOSHISHIGE KIDO, KOICHIRO KANAYA, TETSUYA ...1994 Volume 97 Issue 4 Pages 703-708
Published: 1994
Released on J-STAGE: March 19, 2008
JOURNAL FREE ACCESSWe have newly designed instruments for equilibrium experimentation, using a drop shaft, and studied the behavior and EMG Patterns of frogs with or without unilateral vestibular neurectomy, as a preliminary study at JAMIC (Japan Microgravity Center). The results are reported herein and the efficacy of the drop shaft in equilibrium experimentation is also documented.
1) In unilateral vestibular neurectomized frogs, posture -head tilt, leg flexion on the affected side, and leg extension on the opposite side-is maintained and persists under microgravity. Rolling to the affected side was also observed.
2) The latencies of the EMG responses from M. tibialis anticus and M. longissimus dorsi were prolonged on the affected side.
3) The frog is suitable for use in equilibrium experiments utilizing a drop shaft.
4) The JAMIC drop shaft can be used to obtain constant and stable microgravity, 10-4G for 10sec, which is similar to that in space. Drop shafts are suitable for equilibrium experimentation.View full abstractDownload PDF (2039K)
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