A new method of hearing test using double pulses of variable interval (0-40 msec) was reported. The task of the subjects was to identify the given tone as double pulses. The results so far obtained were as follows; 1) Normal subjects were able to identify the double pulses with the interval of not less than 8-10 msec. 2) The ability of double pulse identification of the patients with conductive deafness was comparable to that of normal subjects, provided that the given tone was properly amplified. 3) The patterns of response of the patients with perceptive deafness were differed from those of normal and conductive deaf subjects. These patterns were classified into three types and called depressed, dispersed and impossible. 4) The patients with inner ear deafness showed the same response pattern as the normal subjects', while central deaf patients often showed the pattern of "impossible" type. 5) Most of congenital deaf patients showed the response pattern of either depressed or dispersed type, though this group was generally considered to have the deafness of inner ear origin. The present result would suggest that in congenital deafness, the lack of postnatal auditory "training" plays an important role in identification of the double pulses. 6) It was considered from the foregoings that the ability of identifying the double pulses was closely related to the function of the central nervous system.
The effect of bumetanide upon the endolymphatic potential (EP) was examined using 46 healthy guinea pigs and following results were obtained. 1) Within a few minutes after intravenous administration of this drug, the EP started to decline rapidly. After reaching the lowest level, the EP started to recover. This recovery could be devided into two phases, namely the initial rapid recovery and the later very slow one. The recovery up to the original level was not obtained in any case for 3 hours observation and the EP recovered to the level of only 30 to 40 mV in cases of a large dose administration (30 to 40 mg/kg). 2) The minimal dose required to affect the EP was 5 mg/kg and the reduction of the EP became larger as the given dose increased. The maximum reduction (the reduction to about -40 mV) was obtained at the dose of 30 mg/kg or more. 3) When the EP reached the lowest level, 20 animals put into ichemic condition by aorta section. The decline rate of the EP in the bumetanide intoxicated animals was much slower than that of the normal ones and approximately proportional to the lowest level reduced by bumetanide. When the lowest level was less than -20 mV, ischemia elevated the EP instead of reducing. These results were discussed combining our previous studies on furosemide and ethacrynic acid. In conclusion, the effect of bumetanide upon the cochlea is almost identical to ethacrynic acid and slightly different from furosemide, and taking the diuretic action into consideration, the present study indicates that bumetanide is less ototoxic than the other two.
The human averaged evoked responses to clicks elicited from the postauricular region were sudied in order to evaluate its clinical use. Subjects were 31 awake adults with normal hearing. They were seated on a chair in a soundproof room. Active electrode was attached to the region just behind the auricle, while reference and ground electrodes were placed on one of the ear lobes and the root of the nose respectively. The responses were amplified and averaged by a medical computer, whose analysis me was set at 50 cosec. 500 signals were averaged in a test run and were recorded by an X-Y recorder. Click stimuli were given through a loudspeaker at intervals of 125 msec. The followings are the results obtained : 1) The response consisted of a negative wave (N) followed by a positive wave (P). Their peak latencies ranged 12-19 msec (N) and 18-25 msec (P). The mean N-peak latency at 70 dB SL was 15 msec. The N-P amplitude was highly variable in both intra- and inter-subject. 2)The positive responses were observed in 20.3, 72.2 % and in 84.0 % at the intensity levels of 10, 40 and 70 dB SL conditions respectively. 3)The distribution of response threshold was as follows : 51.6 % was under 30 dB SL, 25.8 % was 40-60 dB SL and 22.6 % was above 70 dB SL. 4)The intra subject threshold difference was less than 30 dB. 5)The response was dominantly elicited from a small area of about 1 x 2 cm behind the auricula. 6)The amplitude of the response was about 1.2 to 2.5 times larger in the head down position than in the natural upright position. 7)On the basis of these results, this response can be applied in clinical practice, although "response negative" does not necessarily mean the loss of hearing.
The suffering, however, is much greater than in trigeminal neuralgia, because the commonest aggravating factor is swallowing and the patient tends to be afraid of swallowing. The relief of this neuralgia has been achieved by a new method of intraoral block. The procedure consists of block of the tonsillar and lingual branches by the injection of 5 % Phenol in Glycerin and can be applied for the neuralgia with a trigger zone around the tonsil. The result was quite satisfactory. This procedure is extremely safe and simple, and can be performed repeatedly when recurrences occur. Since this procedure does not preclude later operations, this should be adopted as the first choice of treatment.
Clinical and laboratory studies on 104 cases of chronic otitis media were carried out. The results were as follows : 1) Several kinds of non-pathogenic micro-organisms were isolated from 64 % of the control group (113 ears), and no micro-organisms was found in 36 % of them. The bacteria normally residing in the external ear canel was supposed to be Staph. epidermidis. 2) The micro-organisms isolated from otorrhea were mainly Staph. aureus, Staph. epidermidis, Corynebacterium, P. aeruginosa, P. mirabilis, P, inconstans, etc 3) Within several days after acute acceleration of chronic otitis media, Staph. aureus was isolated in most of cases. Genus Proteus, on the other hand, was isolated in a few cases. However, after two months from acute acceleration, Staph. aureus disappeared in most of cases and Genus Proteus apparently increased. 4) The micro-organisms in otorrhea coincided with those at the nosopharynx in 42 % of the examined cases. The type of otitis media gave much influence upon the coincidence of the microorganisms between the middle ear cavity and the upper respiratory tract. Especially, otitis media with perforation at the pars tensa of the ear drum was greatly influenced by upper respiratory infection. 5) Those cases which received bacterial examination within one month from the onset of acute acceleration showed u higher coincidence of the organisms isolated from the middle ear cavity and from the upper respiratory tract than those cases received the examination after one month from the onset. 6) The cases accompanied by upper respiratory infection showed a higher coincidence of the micro-organisms between the middle ear cavity and the upper respiratory tract than those without upper respiratory infection. 7) No influence of inoculum size of the micro-organisms on the examination for antibiotic sensitivity was found, if the type of strain was the same.
Five cases of von Recklinghausen's disease were found in one family. In three of them, bilateral acoustic neurinoma were observed. The pure tone audiometry was performed repeatedly in two of them and the changes of audiograms were studied. Clinical signs and symptoms of these cases seem quite different from those in unilateral acoustic neurinoma. The changes in audiograms revealed the two periods in the progress of hearing loss. They were rapidly increasing periods and slowly increasing periods. These results suggest the etiology of the bilateral acoustic neurinoma in von Recklinghausen's disease is different from other acoustic neurinoma.