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Biomedical subjects

T O-Uchi

Publications and source records attributed to T O-Uchi.

At least 37 records · Page 2Linked to original sources
PubMed1983

The progression of hearing loss in the early stages of sudden deafness.

The pathogenesis of sudden deafness is still not known. Therefore, to clarify its pathophysiology, it is important to know whether the progression of hearing loss occurs in the early stage of sudden deafness. The subjects were 11 patients with sudden deafness showing the progression of hearing loss by pure tone audiometry after the onset of the initial attack of hearing loss. The progression of hearing loss was mostly observed within 4-7 days after the onset of the initial attack. Average hearing loss in initial audiometry was severe and the recovery was poor in the majority of cases. An exploratory tympanotomy was performed in five cases and revealed one case of perilymphatic leak from the round window and another case of suspected round-window membrane rupture. As far as the causes of the progression of hearing loss in the early stage of sudden deafness are concerned, the following could be considered (1) aggravation of viral labyrinthitis, (2) aggravation of the vascular lesion of the inner ear, and (3) rupture of the membranous labyrinth of window(s).

Adolescent↗
PubMed1983

The effect of amphetamine on head and eye movements following vestibular stimulation in squirrel monkeys.

The effect of a single dose intra-muscular injection of amphetamine sulfate on head and eye movements evoked by vestibular stimulation was investigated in squirrel monkeys. Doses injected were 0.5, 0.4, 0.3, 0.2 mg/kg, and control no injections. Amphetamine did not change the gain of vestibular evoked head and eye movements, but prolonged time constant (in function of dose) showing greater effect in eye movements. More than 0.3 mg/kg was found to be a proper dose for this species to maintain an appropriate constant alertness level for vestibular studies.

Amphetamine↗
PubMed1983

Effect of amphetamine on optokinetically evoked head and eye movements in the squirrel monkey.

The effect of amphetamine sulfate injection on head and eye movements evoked by optokinetic stimulus was studied in squirrel monkeys. No change was found in the gain of optokinetic-oculomotor and optokinetic-caputomotor functions, even after the maximum dose (0.5 mg/kg) of amphetamine. Also, no change in eye-head coordination was found. However, amphetamine facilitated the frequency of head nystagmus, whereas that of eye nystagmus did not change. When the poststimulus responses were studied in the dark, both nystagmoid head movement and optokinetic after eye nystagmus showed first phase and second phase. A different effect was found in the duration of these two phases suggesting the existence of distinct generators. Moreover, the synchronized onsets of head and eye nystagmus in both phases, and synchronized occurrence of quick phases indicated the existence of shared neural circuitry between head and eye movements.

Amphetamine↗
PubMed1983

Differential diagnosis of central vestibular disorders by combined tests with perrotatory ocular fixation and auditory brain stem response.

The purpose of this study is to investigate the diagnostic value of using the damped pendular rotation test (DPRT) (1) with an ocular fixation (ocular fixation test, i.e. OFT), and (2) in the dark with the eyes open, jointly with auditory brain stem response (ABR) audiometry. Impairment of ocular fixation was found in patients with either brain stem lesions, cerebellar lesions, or cerebellopontine angle tumors. A collective evaluation of the findings of OFT with those of ABR audiometry has suggested the possibility of differentiating upper brain stem lesions from lower brain stem lesions, tumors of the IVth ventricle, and cerebellar tumors. However, differentiating IVth ventricle lesions from tumors involving the cerebellar vermis extending into the IVth ventricle by this battery of tests was somewhat limited.

Audiometry, Evoked Response↗
PubMed1983

Circulating immune complexes in steroid-responsive sensorineural hearing loss and the long-term observation.

Immune complexes (IC) were determined quantitatively in 53 cases of bilateral sensorineural hearing loss (SNHL) by the Raji cell immuno-fluorescence assay. The 53 cases consisted of 47 cases of unknown etiology, 5 cases with positive syphilitic reaction and 1 case of aortitis syndrome. High IC values were indicated in 5 cases, of which one was of aortitis syndrome and 4 were of unknown etiology. The case of aortitis syndrome and 3 out of the above 4 cases of unknown etiology were responsive to steroid. There were 2 cases which showed normal IC values but reacted to steroid. All patients of the steroid-responsive SNHL were female. If hearing improves by steroid administration, it is necessary to suspect autoimmune SNHL. It has been proved that in SNHL which is responsive to steroid, the hearing level before the start of treatment may be maintained by long-term steroid therapy.

Adult↗
PubMed1983

Diagnostic value of auditory brain stem responses (ABR) in differential diagnosis between cochlear deafness and acoustic neuromas.

The diagnostic value of ABR for the differential diagnosis between cochlear deafness (CD) and acoustic neuromas (AN) was investigated. The following ABR parameters against 80 dB click stimulation was compared between CD and AN; (1) incidence of presence of each wave, (2) wave I latency, (3) wave III latency, (4) wave V latency, (5) I-III interpeak latency, (6) I-V interpeak latency, (7) right and left latency difference of wave III, (8) right and left latency difference of wave V, and (9) ABR pattern. It was concluded that a battery of 6 latency parameters (3-8) is very useful for the differential diagnosis between CD and AN and therefore it can be expected to be used as a powerful tool for finding out the small size AN.

Audiometry↗
PubMed1982

Fluctuating hearing loss and recurrent vertigo in otosclerosis. An audiologic and temporal bone study.

This report summarizes audiologic and temporal bone findings in a 47-year-old white female with recurrent attacks of vertigo, tinnitus, and bilateral hearing loss. A series of audiograms, obtained over a 15-year period, showed a fluctuating mixed (sensorineural and conductive) hearing loss with a relatively flat configuration in the left ear and a relatively stable, mild sensorineural loss with a sloping contour in the right ear. Temporal bone studies revealed the existence of otosclerotic foci bilaterally. In the left ear, the otosclerotic focus has grown close to the utricular and lateral ampullary nerves, displaced and ankylosed the stapedial footplate, invaded the endosteal zone (1,000-2,000 Hz area), and deformed the lateral cochlear wall. In the right ear, the otosclerotic invasion was limited to the inferior portion on the promontory (vestibular cecum) and round window niche.

Audiometry↗
PubMed1981

Cochleo-saccular degeneration in one of three sisters with hereditary deafness, absent gastric motility, small bowel diverticulitis and progressive sensory neuropathy.

This is a report of cochleo-saccular degeneration found in temporal bones from a patient who had suffered from slowly progressive and total sensorineural deafness which had an inherited origin. At age 8, this patient began to complain of hearing loss, and by age 10 she was totally deaf. The patient was 1 of 3 female siblings who have suffered from an exactly identical progressive disease: deafness, absent gastric motility, small bowel diverticulitis and ulceration, and sensory neuropathy. The temporal bone pathology found in this case was the degenerative change in the cochlear duct and sacculus. No pathology was found in the utriculus and semicircular canals.

Adolescent↗
PubMed1981

Inner ear pathology in deaf mutism.

This is a report of the inner ear pathology found in a pair of temporal bones from a deaf mutism case. This patient's spouse and four of six children were deaf mutes. Some members in the succeeding generation were also known to be deaf mutes. The temporal bones (horizontally sectioned) showed the cochleo-saccular degeneration with exactly similar extent bilaterally. The scala media and the saccular space were atrophied, and displaced membranes were attached onto the degenerated sensory epithelia in many areas, but some portion of the scala media exhibited an ectatic view. The cochlear and saccular nerves were severely reduced. In addition to the pathology found in the pars inferior, the internal auditory canal and the cochlear aqueduct were enlarged. All end organs and nerves in the pars superior were intact.

Aged↗
PubMedDate not supplied

Functional and histological evaluation of the facial nerve in patients who have undergone hypoglossal-facial nerve anastomosis after removal of cerebellopontine angle tumors.

Facial nerve specimens removed from ten patients who underwent hypoglossal-facial nerve anastomosis for facial palsy following removal of cerebellopontine angle tumors were studied histologically. Facial nerve function prior to the anastomosis surgery and the degree of postoperative functional recovery were compared with the histological results. The recovery of facial palsy after the anastomosis surgery was excellent or satisfactory in nine patients and the endoneurium within the nerve fascicles was well-preserved. The recovery of facial palsy was poor in one patient who had severe fibrosis of the endoneurium. The histological and ultrastructural features of the facial nerve were closely related to the occurrence of facial palsy prior to tumor removal, the status of the nerve after tumor removal, and the interval between tumor removal and anastomosis surgery. Based on these histological and functional relationships, the timing and indications for anastomosis surgery are discussed.

Adult↗
PubMedDate not supplied

Comparative morphometry of mammalian otolith organs.

The endolymphatic volume of the utricle and the saccule and the surface area of the saccular macula were measured in eight mammalian species, including humans. The results confirmed that all measurements increased slowly but consistently correlating with increases in body weight. However, differences in these endolymphatic volumes or macular surface areas might also be influenced by functional characteristics among different species rather than simply reflecting geometrical comparability.

Animals↗