著者

矢部 多加夫 澤木 誠司 中本 吉紀 伊藤 茂彦 小寺 一興 中村 雅信

出版者

Japan Audiological Society

雑誌

AUDIOLOGY JAPAN (ISSN:03038106)

巻号頁・発行日

vol.40, no.4, pp.223-230, 1997-08-30 (Released:2010-04-30)

参考文献数

17

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スポーツクレー射撃時の衝撃音が射手に与える影響について検討するために, 衝撃音測定用のダミー人形装置 (KEMAR) を用いて衝撃音を測定し, 63名のクレー射手を対象に純音聴力検査と質問紙調査を実施した。 1) 衝撃音のピーク音圧は約155dBで, 2msec前後にピークをもち, 約50msecで減衰した。 2) 銃口側耳と反対側耳間にピーク音圧差が認められ, 耳介の集音作用が考えられた。 3) 音響外傷予防用具の遮音効果についてはイヤープラグとイヤーマフの併用, イヤープラグ, イヤーバルブ, イヤーマフの順であった。 4) 高音域で明らかな高音急墜ないしC5 dipを示した異常群は非異常群に比べ平均年齢が高く, 平均経験年数が長く, 予防用具使用率が低率を示した。 音響外傷予防用具は遮音に効果的で, 予防用具の必要性と適切な使用法についての今後の一層の普及, 使用率の向上が望まれる。

著者

横田 淳一 太田 康 矢部 多加夫 霜田 里絵

出版者

一般社団法人 日本めまい平衡医学会

雑誌

Equilibrium Research (ISSN:03855716)

巻号頁・発行日

vol.75, no.1, pp.7-15, 2016-02-26 (Released:2016-04-01)

参考文献数

30

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Opalski's syndrome is considered to be a variant of lateral medullary infarction (Wallenberg's syndrome) with ipsilateral hemiplegia. Although dizziness/vertigo or ocular motor abnormalities commonly occur in Wallenberg's syndrome, these abnormalities are scarcely encountered in Opalski's syndrome. In the present study, two patients with Opalski's syndrome experiencing vertigo/dizziness were evaluated by electronystagmography (ENG). The characteristic findings of ENG were as follows: (1) horizontal nystagmus beating toward the contralateral side of the lesion, (2) tonic conjugate deviation to the side of the lesion (case 2), (3) hypometric saccade toward the side of the lesion and hypermetric saccade toward the contralateral side, (4) smooth pursuit was impaired to the ipsilateral side of the lesion, (5) slow phase peak velocities of OKN were reduced bilaterally, while the steady-state velocities were preserved, and (6) impaired visual suppression (VS) of the slow phase of caloric nystagmus on the ipsilateral side. Among these features, (3) and (4) were the most remarkable findings in our patients. In our present cases, the characteristic directional preponderance of the saccadic and smooth-pursuit eye movement disorders was just the reverse of those observed in Wallenberg's syndrome. Several lines of neurophysiological evidence suggest that in Wallenberg's syndrome, the impaired saccadic and smooth-pursuit movements are caused by dysfunction of the caudal fastigial nuclei. In contrast, after experimental lesioning of the posterior vermis (lobules VI and VII), the directional preponderance of the saccadic and smooth-pursuit eye movements is just the opposite. The findings in our cases were consistent with these observations. Consequently, the findings in our case were presumed to be originated from dysfunction of the posterior vermis. As for reduction of the bilateral slow-phase peak velocities of OKN, it appears to be derived from dysfunction of the flocculus/paraflocculus, and reduction of the ipsilateral VS may be derived from dysfunction of the flocculus or nodulus. MRI in our cases revealed lateral medullary infarction, but no lesions in the cerebellum. Therefore, it was assumed that the above ocular motor abnormalities in our cases may have been mainly derived from lesions of the inferior cerebellar peduncle disrupting the climbing fibers from the contralateral inferior olivary nuclei to the posterior vermis, flocculus/paraflocculus, and nodulus.