軟口蓋ミオクローヌスに伴う他覚的耳鳴の1症例

抄録

An 8-year-old girl complained of rhythmical high pitched tone tinnitus in both ears. The tinnitus became audible to the examiner by inserting an otoscope and was synchronized palatal myoclonus. There were no obvious abnormalities on pure tone audiometry, X-ray, MRI, EEG or other neurological examinations.
The contraction of the Eustachean tube due to palatal myoclonus was observed through a nasopharyngeal fiberscope. Tinnitus was attributed to the constraction of the tube because the sounds occurred when the tube opened.
Sound analysis of the tinnitus showed that the tinnitus had a duration of 10-20 ms, frequency of about 2 kHz and irregular rythme of 100-150 times per minute.
The literature on the origin and mechanism of objective tinnitus is reviewed. We consider the origin of tinnitus in this case was Eustachean tube contraction due to essential palatal myoclonus.