The Changes of Cochlear Blood Flow and Auditory Evoked Potentials by Compression of the Acoustic Neurovascular Bundle.

声神经血管束受压引起的耳蜗血流和听觉诱发电位的变化。

• 批准号: 08671975
• 负责人: URA Masaharu
• 金额: $ 1.41万
• 依托单位: University of Ryukyu
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08671975/
• 关键词: neurovascular bundle of internal auditory canal; Cochlear blood floe (CoBF); laser doppler flowmetry; electro cochleography; compound action potential (CAP); auditory brainstem response (ABR); 聴神経腫瘍; carbogen; 蝸牛血流; 聴性脳幹反応; Carbogen; レーザートップラー血

1)According to the changes in CoBF,CAP and ABR by compression of acoustic neurovascular bundle, we classified these changes into three types of hearing disturbance.(1)In neural types, Which noticed in 66.7% of cephalad compression cases, prolongation of I-II interpeak latency and decrease of the amplitude of wave II-IV without decrease of CoBF and changes of CAP were noticed as the results of neural conduction blockage.(2)In cochlear insufficiency type, which noticed in 71.4% of caudal compression cases, allacoustically evoked potential was disappeared folliwed by cochlear ischemia.(3)In mixed type, as a result of both neural and cochlear ischemia, all acoustically evoked potential was disappeared transiently with partially decreased CoBF.The results indicate that the cochlear nerve or the internal auditory artery is more susceptible to damage by compression of a cephalad or a caudal compression point, and that the compcepression position is an important determinant in the type of auditory dysfunction and the degree of hearing loss.2)The following thing became clear from the changes of CoBF and CAP during put and removes of compression on the neurovascular bundle.(1)Disappear of CAP did not mean the complete shut off of CoBF,it occurred when CoBF decreased 70% or more.(2)CAP recovered promptly after resuming blood fiow, but only 30% is recovered with more than 30 miniutes complete compression.(3)When blood flow was left at all, CAP recovered about 60% or more even after 30 minute's compression.These findings suggested that both the degrees of compromise of CoBF and the duration of ischemia are important factors affecting the recovery of auditory function.3)Furthermore, after administration of carbogen, the cochlear blood flow was increased and the improvement of CAP was noticed.We emphasize that carbogen inhalation give the validity toward acute cochlear hearing impairment.

1)根据听神经血管束受压引起的CoBF、CAP和ABR的变化，我们将这些变化分为三类听力障碍。(1)在神经类型中，66.7%的头侧受压病例中发现I延长-II 峰间潜伏期和波 II-IV 波幅降低，但 CoBF 降低，CAP 变化，作为神经传导阻滞的结果。 (2) 在耳蜗功能不全型中，发现71.4%的尾部受压病例中，所有声诱发电位消失，随后耳蜗缺血。(3)混合型中，由于神经和耳蜗缺血，所有声诱发电位短暂消失，CoBF部分下降。结果表明耳蜗神经或内听动脉更容易受到头侧或尾侧受压点的压迫而损伤，并且压迫位置是决定听觉功能障碍类型和听力损失程度的重要因素。2)从神经血管束施加和解除压迫过程中CoBF和CAP的变化可以清楚地看出以下几点。(1)CAP消失并不意味着CoBF完全关闭，当CoBF下降70％或更多时发生。（2）CAP在恢复血流后迅速恢复，但完成30分钟以上仅恢复30％ (3)当完全不留血流时，即使压迫30分钟，CAP也能恢复约60%以上。这些结果表明，CoBF受损程度和缺血持续时间是影响听力恢复的重要因素。 3)此外，给予卡波金后，耳蜗血流量增加，CAP得到明显改善。我们强调，吸入卡波金对急性耳蜗听力损伤具有有效性。

项目成果

Anzhou Tang, Masaharu, Ura, Masayuki Yamauchi and Yutaka Noda: "Cochlear ischamia and changes in Compund action potentials in the Guinea Pig." Journal of Otolaryngology of Japan. Vol.99, No.2. 320-326 (1996)

Anzhou Tang、Masaharu、Ura、Masayuki Yamauchi 和 Yutaka Noda：“豚鼠耳蜗缺血和复合动作电位的变化。”

唐 安洲, 宇良 政治, 山内 昌幸, 野田 寛: "レーザードップラー血流計を用いた蝸牛血流の計測" 耳鼻と臨床. 42・4. 373-377 (1996)

Anzu Tang、Seiji Ura、Masayuki Yamauchi、Hiroshi Noda：“使用激光多普勒血流计测量耳蜗血流”耳鼻喉科和临床科学 42・4（1996）。