The relationship between caloric responses and symptoms was examined. Caloric tests were performed in 61 patients treated with streptomycin sulfate (SM). The patients were divided into 3 groups ; group I (12 patients) in which caloric responses were reduced unilaterally or bilaterally, and there were inner ear, mainly vestibular, symptoms ; group II (16 patients) with reduced caloric responses and no symptoms. Group III (33 patients) with no symptoms and normal caloric responses. The average age of group I patients was higher than that of group II patients. The total dose and the duration of SM therapy was less in group I than in group II. The average of each dose of SM was similar in the three groups. The results suggest that the caloric response is useful as a monitor for the prevention of SM ototoxicity. Vestibular symptoms were often found in older patients treated with SM and also in those who had received small amounts of SM.
Our first paper described a new method of inducing nystagmus by moving the sound stimulus from one ear to the other ear repeatedly. In this paper, eye movements induced by the audiokinetic stimulus without following the moving sound source are discussed and compared with eye movements when the subject follows the moving sound source in the head without moving the head. The latter test was named the “Auditory Tracking Test”. With this test we can determine easily whether or not the eye movement is audiokinetic nystagmus.
To clarify the correlation between the directions of body sway, auto-and cross-correlation functions were computed. Two dimensional sways of the body center of gravity were recorded by stabilometer. The data were transmitted to a computer in the form of digital values after AD conversion sampled at intervals of 20 msec. Slow waves less than 0.15 Hz from the linear stabilogram were cut off with a digital filter. Auto-and cross-power spectra were calculated with fast Fourier transformation. Auto-and cross-correlation functions could be produced from these two power spectra. In 30 normal subjects with eyes open, there was little correlation between the directions of body sway. With eyes closed, a strong correlation was obtained in only two subjects at a frequency of about 0.22 and 0.25 Hz. It seems that frontal and sagital body sway oscillates independently in each direction. Ten out of 30 patients suffering from Meniere's disease showed a strong correlation in frontal and sagital directions with eyes closed. In two patients, the correlation was high even with eyes open. The frequency band was about 0.220.61 Hz, but the phase difference was relatively large. In an investigation of 8 caloric-stimulated normal subjects, a strong correlation was observed when the amplitude of oscillations was large. The harmonic frequency band was about 0.180.65 Hz, and a phase difference was scarcely noticed. The human body acts like a pendulum when the vestibular system is disturbed.
Vestibular stimulation is a popular clinical treatment for enhancing the acquisition of central compensation in patients with unilateral vestibular disturbance, but whether visual and proprioceptive stimulation can also influence recovery from vertigo is not known. A new exercise combining vestibular, visual and proprioceptive stimulation is described, and the reasons that human equilibrium is supported by such a multi-channeled system are discussed. Repeated application of this exercise in five patients with vestibular neuronitis showed good results in this preliminary study. Dysequilibrium and dizziness during head and body movement were usually prolonged at the start of rehabilitation. However, the mean time course for relief of both subjective and objective disturbances was shorter in the five trained than in nine untrained patients.
Differences of history, symptoms and signs of 19 patients with cerebellopontine angle tumor diagnosed by Otolaryngologists and physicians with other specialities were investigated. Deafness was the main symptom which led to final diagnosis by Otolaryngologists in 77% of patients. On the other hand, symptoms of high cerebellar pressure was the main symptom which let to the final diagnosis by physicians of other specialities. It is emphasized that deafness is a cue for the diagnosis of cerebello pontine angle tumor.
We have presented an analytical theory approach based on a new image processing technique for measuring eye movements quantitatively. This recently developed system makes it possible to analyze not only horizontal and vertical but also rotatory eye movements simultaneously. The system consists of an infrared lighting apparatus, a very small infrared video CCD camera, a VTR controllable by computer, and microcomputers. Six normal adult subjects were used in this investigation and the maximum slow phase velocity of the rotatory component of caloric induceed nystagmus was found to be 0 to 6 degrees /sec.
To evaluate quantitatively the development of equilibrium function in children, the author investigated head movement (H. M.) and movement of the body's center of gravity (M. C. G.) in six agegroups of children and adults, using a cephalograph to record H. M., a straingauge-platform to record M. C. G., and a technical computer. One hundred twenty-six healthy subjects aged 4 to 28 years were instructed to stand with feet close together on the platform with eyes open and with eyes closed for 60 seconds each. 1. The area and total length of H. M. and M. C. G. decreased with age. They were significantly larger in children younger than 12 years of age than in adults. Changes in the swaying velocities of H. M. and M. C. G. in 8 directions paralleled the area and total length of sway. 2. The averaged divisional frequencies of H. M. and M. C. G. decreased with age both in the lateral component and in the anteroposterior component. They were significantly larger in children younger than 9 years of age than in adults. 3. In all six agegroups the total length, swaying velocities and averaged divisional frequencies of H. M. were smaller than those of M. C. G. 4. The ratio of the anteroposterior component to the lateral component in H. M. did not differ among the agegroups. On the other hand this ratio in M. C. G. was significantly larger in children younger than 9 years of age than in adults. 5. The ratio of the total length of H. M. to that of M. C. G. was significantly larger in children younger than 9 years of age than in adults. 6. The ratio of the area and total length of H. M. and M. C. G. with eyes closed to those with eyes open did not differ among the agegroups. These results suggest that the body sway of children is not only larger than that of adults, but also different from it in nature. It appears that the ratio of H. M. to M. C. G. is larger in children than in adults, and that the ratio of the anteroposterior component to the lateral component in M. C. G. is also larger in children than in adults.
Vestibular habituation in guinea pigs was investigated by repeated unidirectional velocity steps, and the influence of TRH on vestibular habituation was surveyed. 1) Vestibular habituation was still present 18 days after the end of 15 days of training. 2) It appeared that TRH inhibited the acquisition of vestibular habituation.
Recently, several studies on human standing posture and body sway have been reported. Many factors influencing human posture have been studied by many investigators. The present study aims at elucidating the influence of visual conditions on body sway. The sway of the center of gravity produced by 5 types of visual conditions (with unfixed visual focus, with eyes focused 50 cm. or 1 m. straight ahead, with eyes closed and with eyes blindfolded) was examined in 38 normal subjects. 1) Sway area and shifting length with eyes closed and with eyes blindfolded were similar. 2) The sway area with eyes focused 50 cm. ahead was significantly smaller than that with unfixed focus or eyes focused 1 m ahead. The shifting length was similar under all three visual contitions.
The head-shaking test (HST) was used in the examination of 338 patients who complained of virtigo or dizziness in our clinic. Head-shaking nystagmus (HSN) was observed in 131 patients (38.8%) -a higher incidence than that of other types of nystagmus. Nystagmus was monophasic in 107 patients (81.7%) and biphasic in 24 (18.3%). HSN was usually horizontal or had a rotatory component. Vertical or oblique nystagmus was observed in only ten patients. An abnormal righting reflex and an abnormal deviation reaction were more frequently observed in HSN-positive patients. The first phase of nystagmus was directed to the opposite to the deviation side of deviation reaction, opposite to the side of hearing loss and to that of CP in the caloric test. HSN is very common and is useful in determining the location of a lesion. Therefore HST is a very important aid in equilibrium examinations.
Three patients with Meniere's disease were treated with Aplactan, Contomin, Isobide and Triomin immediately at the onset of premonitory symptoms, such as tinnitus, hearing loss, sense of fullness of the affected ear. To differentiate between therapeutic effects and spontaneous improvement these drugs were prescribed many times for each patient. Case 1, a 74-year-old male, was given Contomin, Aplactan and Triomin 10 times for 11 premonitory conditions from Nov. 1987 to May 1988. The attack was aborted 4 times. Case 2, a 58-year-old female, was treated with Aplactan 7 times for 13 premonitory conditions from Mar. 1988 to May 1988. Vertigo was aborted 5 times. Case 3, a 45-year-old male, was given Isobide, Triomin, Aplactan and Cercine 2 times for 9 premonitory conditions from Jan. 1988 to Apr. 1988. Vertigo was aborted once. These results indicate that drug therapy in the premonitory stage of an attack can prevent attacks of vertigo in Meniere's desease.