Tomokazu Kamio

New Neurotological Test for Detecting Cerebellar Dysfunction Vestibulo-Ocular Reflex Changes with Horizontal Vision-Reversal Prisms

Adaptation of the vestibule-ocular reflex (VOR) was studied in 26 normal subjects and 15 patients with cerebellar lesions, using horizontal vision-reversal prisms. In normal subjects, adaptation of gain after wearing prisms for one hour was approximately 50% of the VOR value in the dark. In contrast to this, patients with cerebellar lesions showed less adaptation, approximately 20% after a one-hour forced adaptation task. These cases showed three different types of abnormalities: 1) high gain before wearing prisms and normal adaptation, 2) high gain before wearing prisms and reduction of adaptation, 3) normal gain and reduction of adaptation. From these results, it is suggested that observation of the effect of vision-reversal prisms on the VOR may permit the detection of cerebellar lesions of a type or subtlety which escape established tests.

Suspected Sacculogenic Dizziness; Surgical Treatment By Partial Ablation — A Case Report

This report concerns the findings and subsequent surgical procedures in a case of a 36-year-old male who complained of a four year history of frequent attacks of dizziness and tinnitus in the right ear. The dizzy attacks were vibratory in nature, or short duration and of short intervals, and always simultaneously accompanied by tinnitus. Hearing acuity in the right ear was slightly impaired but within normal limits. The history, clinical examination and pertympanal inner ear anesthesia supported the diagnosis of a lesion in the labyrinth, possibly in the otolithic organs as opposed to the ampullae. Surgical extirpation of the utricle and the lateral and anterior ampullae was initially attempted. The operation temporarily abolished the dizzy attacks and hearing was preserved. However, the patient suffered a recurrence of his symptoms two months after the surgery. Subsequent to this recurrence, a surgical modification of the saccule was then attempted which successfully abolished his dizziness but unfortunately destroyed the hearing in this ear. The essential objectives outlined in this report are twofold. Primarily, the authors have attempted a description of the clinical manifestations of an inner ear lesion localized in a specific part of the labyrinth. Secondly, a description was presented of the partial success of selective surgical ablation of damaged inner ear structures with an attempt to preserve the unaffected individual endorgans.

Speech Audiometry One Year after Tympanoplasty.

Speech reception thresholds were analyzed in 71 patients with chronic otitis media one month before and after and one year after typmpanoplasty. Bone conduction thresholds of all the subjects were within the normal range.In 19% of the subjects improvement in the reception threshold was observed one month and one year after the operation. The air conduction threshold was also markedly improved after both one month and one year.In 12% of the subjects the speech reception threshold improved after on month, but one year later the threshold had reverted to the pre-operation level. The air conduction threshold was improved after one month, but after one year it was in the low frequency zone.In 17% of the subjects the speech reception threshold remained the same after one month but had improved by one year after surgery. The air conduction threshold also showed no significant change after one month but was improved after one year.In 33% of the subjects no significant change was noted in the speech reception threshold either one month or one year after the operation. The air conduction threshold the same.The results suggest that it is too early to judge the improvement of the speech reception threshold one month after tympanoplasty. Therefore, speech audiometry should be carried out one year after tympanoplasty.In several cases the changes in the air conduction threshold and those in the speech reception threshold were different. Accordingly, pure tone audiometry and speech audiometry are considered necessary to evaluate hearing after tympanoplasty.

Speech audiometry before and after tympanoplasty.

The speech reception threshold and maximum discrimination score were analyzed in 158 patients with chronic otitis media before and after tympanoplasty.The air conduction threshold improved significantly in low and middle frequencies after tympanoplasty. The speech reception threshold also improved significantly, but the maximum discrimination score, did not change significantly.In the patients with improved speech reception threshold after tympanoplasty, the air conduction threshold was improved in the low and middle frequencies. In the same patients, however, there was no improvement in the high frequencies. On the other hand, in patients whose speech reception threshold was worsened after tympanoplasty, the air conduction threshold did not change in the low and middle frequencies and was aggravated in the high frequencies.In 60% of the patients whose air conduction threshold improved after tympanoplasty, the speech reception threshold also improved, while in only 20% of the patients whose air conduction threshold was aggravated after tympanoplasty, the speech reception threshold was also aggravated.These results suggest that both pure tone audiometry and speech audiometry are necessary to evaluate hearing differences before and after tympanoplasty.

Histopathological Study of Bacterial Labyrinthitis

We report here the temporal bone histopathology of a 50-year-old woman who died of renal insufficiency due to diabetes mellitus. She had complained of profound deafness of both ears and dizziness. She had no caloric response, and spontaneous nystagmus towards the left was observed 20 days before death.The temporal bone findings indicated typical bacterial labyrinthitis. Infectious changes indicated typical bacterial labyrinthitis. Infectious changes invaded the cochlea through the round window and destroyed the cochlea. The pathology of the left ear was greater than that of the right ear. These inner ear changes correlated well with auditory and vestibular function tested before death.

Changes of vestibular function after endolymphatic sac surgery.

In order to clarify the direct influence of endolymphatic sac surgery on vestibular function, changes of symptoms and positional nystagmus of 23 patients were analyzed before and after surgery.The incidence of dizziness was highest 7 to 10 days after surgery. During the same period, positional nystagmus was the most prominent. Two months after surgery, the incidence of dizziness had decreased significantly, and positional nystagmus had disappeared in most cases.This analysis revealed that the direct influence of endolymphatic sac surgery on vestibular function was greatest 7 to 10 days after surgery, and that it took about two months to disappear.

Tinnitus measurement and treatment - Part. 3 Follow up study on the long-term use of band-noise masker.

A follow up study was carried out of 12 patients using band-noise masker for 6 months to 3 years.Various auditory tests and measurements of tinnitus were performed before and after the long-term use of band-noise tinnitus masker: loudness balance, masking and pitch match tests.None of the 12 patients showed any remarkable changes in hearing at the 7 frequencies tested, from 125 to 8000Hz. Tinnitus frequency obtained by the pitch match method demonstrated no changes after long-term listening to band-noise. The contralateral loudness balance method indicated changes of tinnitus loudness; however, both the ipsilateral loudness balance method and the masking method showed no remarkable changes of tinnitus loudness after the long-term use of a tinnitus masker.We conclude that the long-term use of a band-noise masker has no effect on the pure tone threshold as long as close follow-up examinations are performed.