The author has already published many studies concerning the ossicular chain of the ear with his coworkers. Morphologically its atmospheric architecture is measured by means of the X-ray examination and solid geometry, and then confirming its values thr-ough the microscopic examinations. The conclusion obtained is that the ossicular chain may activate its function independently through the navel to the short process of the malleus, the double structure of the malleo-incudal articulation, and the anterior footh to the posterior footh of the stapes, This con clusion was affirmed by several animal experi ments and also by results of the audiometrical exa-minations in the cases of congenital misdevelope-ment of ossicular chain, tubal obstruction, or acute or chronic middle ear inflammation, and the states of improvement of hearing by the surgical operatio-ns•f tympanoplasty, stapes-mobilisation, fenstration of the foothplate of stapes, interposition of veinflap between the footh-plate of stapes and vestibule. The summarised conclusion is that the function of tone conduction of the ossicular chain may consistof two modes, one of which is that of low tones acc-ording to Helmholtz's leverhypothesis, and the other is that of high tones according to another mecha-nism(perhaps direct transmission), and the mix-ing center of these twomodes may be on abot4000cps. with about 25db deviation.
The labyrinthine deviations of a certain subject proved by several clinical tests of the vestibulo- spinal reaction are considered to direct towards one constant side but they often direct towards each opposite side in upper extremities and in lower ones respectively. This phenomenon is called the dissociation of the vestibulo-spinal reactions. The authors investigated the dissociation between the stepping test and the blindfolded vertical writing test (Fukuda) using another test of the vestibulo-spinal reaction, the arm-tonus reaction (Wodak, Fischer) i.e. the lowering of each upper extremity stretched forwards and the deviation of the head, upper extremities and the trunk towards one side. 1. Generally the spontaneous deviation of the head, upper extremities and the trunk are directed towards the side of the impaired labyrinth, but, accompanied by the healing process of the disease, the direction of the deviation changed towards the opposite side i.e. towards the side of the unimpaired labyrinth. The former deviation must be an expression of the stage of disturbance while the latter one an expression of the stage of coordination according to Fukuda's theory. 2. The head, upper extremities and the trunk righted themselves from the deviated positions in this order. In stages of this healing process, the dissociation between the stepping deviation and the writing deviation was observed occasionally, i.e. the former deviated towards the side of the impaired labyrinth while the latter deviated towards the side of the unimpaired labyrinth. 3. In most clinical cases the positive arm-tonus reaction, especially the spontaneous lowering was observed only in the upper extremity of the same side as the impaired ear through the whole progress of the disease. However, the arm-tonus reaction induced by caloric stimulation which evoked an experimental eye nystagmus at first braught about a lowering of the upper extremity of the same side as the caloric stimulated ear, and after a while, at which an eye nystagmus almost ceased, the lowering of the upper extremity of the opposite side i.e. the side of the unstimulated ear was seen.
A case of unexpected harm of Thorotrast, causing the chief complaint of hoarse voice and cervical tumor was reported. The tumor was most probably produced by Thorotrast extravasated at the time of injection. Therefore, the harm was not a typical side effect of Thorotrast. Because of the extravasation of the substance, various examinations failed to reveal any positive findings except for an abnormal radioactivity in and around the tumor. The responsibility of modern medicine in iat-rogenic diseases which are of increasing importance of late is emphasized.
1) Reported was a case of capillary hemangi-oma in the right side of pharynx of a 38 year-old male. 2) The tumor, bluntly disssected transorally, was a globular mass, 5cm in diameter and 37 gram in weight. 3) Histological diagnosis of capillary hemangi-oma was made, taking into consideration the prese-nce of small, erythrocyte-containing vascular lumen. 4) Postoperative course was uneventful, with no resultant functional disturbance left.
1) Audiometry was done with 120 normal persons, 20 persons out of each generation from the 2nd to the 7th decade. Mean value, standard deviation, confidence limit of population mean and abandonment limit of normality were calculated for the hearing loss in each generation. 2) The result provided a good objective crite-rion for the interpretation of presbyacusis, thus distinguishing physiologic presbyacusis from non-physiologic.
By piercing a microelectrode through roundwin-dow membrane, influence on the endocochlear d, c. potential of guinea pigs under acoustic stimulation was studied experimentally, and the following re-sults were obtained. 1) By acoustic stimulation, changes of endoco-chlear d. c. potential were observed in both peri-and endolymphatic space, and both in per- and pos-tstimulatory period in spite of duration and frequ-ency of stimulus tone. 2) In endolymphatic space the endolymphatic d.c. potential decrease by tone stimulation. The course of these changes were generally as follows : as the tone is begun the d.c. potential falls rectangurally and then exponentially decre-ases, and when the tone is stopped the potential rises rectangurally and then exponentially increases to the original value of the potential. But sometimes even in normally (fresh prepara-tion?) the endolymphatic d.c. potential increases responding to low frequency and weak intense sou-nd. 3) The latency of these changes was very short as C.M. and could not measured. 4) The changing value of this potential was li-near at weak intense sound, but over about 75db S.L. become nonlinear. Those value were larger than low frequency tone under same sensation le-vel. 5) In perilymphatic space (scala tympani) thepoalrity of this phenomenon was antagonistic and the value was smaller than in the endolymphatic space (about 1(8). The course of this phenomenon in perilymphatic space was like that of the endo-lymphatic space under low frequency tone, but un-der higher frequency tone the wave form becomes similar to the envelop curve of the stimulus tone. 6) At asphyxia, changing value of this pheno-menon becomes smaller as decrease of endolym-phatic potential, and defficiency of oxygen became higher, and this d.c. potential becomes negative relative to perilymphatic potential. Just at this ti-me the polarity of this phenomenon changes to the opposit side. From these results author considers the Summating Potential to be the changes of endo-cochlear d.c. potential under tone stimulation and those changes are observed also in poststimulatory period
A mixed tumor of Naevus sebaceuscum and Naevus pigmentosus was confirmed in the external auditory canal. Authors study on the benign tumor in the external auditory canal showed had been reported in Japan. That was about 120 cases. Also, 10 cases of Naevus pig. and 6 cases of Melanoma in the external auditory canal and 1 case of uncertain diagnosis was found. Age, sex, site of origin, size, and degree of malignancy was also observed.
Lately, many methods of calculatiing the average hearing loss for occulational deafness are discussed. A new procedure for such a method is proposed and was centered on the tone range impaired and the pattern of the development of hearing impair-ment. A classifing criteria as shown in fig. was basedon the average hearing loss at the middle and hig-her frequency range. The air conduction audiograms in 237 persons (474 ears) working under the noise exposure in a certain factory could be divided in to 0, A and B groups. The chief results were as follow: 1) Occupational deafness was found in 66% of the screening test (1000, 4000 cps 20db). 2) 0 group showed slight hearing loss under 20db at the middle and higher frequency range in 16% of 311 audiograms. 3) A group showed hearing loss under 20db at middle frequency range and over 20db at the higherfrequency range, in 57% of all ears. There appea-red in 41% a dip type hearing impairment with peaks around 4000cps in this group. Bad subjective symptom of hard-hearing. Fi-fty percent of this group. A considerable loss of hearing at 2000.--3000cps tone range was formd in many of this group. 4) B gooups showed loss over 20 db at the mid-dle and higher frequency range, in 14% in all ears. The number of afflicted ears increased as the year of service increased and were especially seen most frequently in those with records over 20 years of service. 5) The author found that the decrease of hea-ring tend to become worse in proportion to the nu-mber of working years. However, a significant diff-erence was not noticed in decibel hearing loss among the classfication of age in the group of working years.