Matsuura S, Kuno M, Nakamura T
Acta Otolaryngol. 1986 Jul-Aug;102(1-2):12-9. doi: 10.3109/00016488609108640.
Auditory evoked responses (AERs) were recorded from the primary cortex, medial geniculate body (MG), inferior colliculus (IC) and cochlear nucleus (CN) of the cat anesthetized with sodium pentobarbitone to examine the effects of increased intracranial pressure (ICP) on neural activity in the different levels of auditory centres. ICP was increased by injecting saline solution into the intracranial space and a tone burst was used for activating the auditory centres. Cortical response (ACR) began to decrease in amplitude from about 30-40 mmHg of ICP. A decrease in amplitude of MG response and that of IC response followed in the order with a further increase in ICP. CN response was most resistant and usually remained even when ACR and MG responses were totally abolished. Recovery of the AERs followed a release of the increased pressure in the reversed order to the decrease in the AERs. When an increase was repeated with a short interval of pressure release such as 5 to 10 min, recovery of ACR became much slower and no recovery was sometimes observed 30-60 min after the release of ICP increased to a level below 100 mmHg. A discussion was conducted on the origin of the changes in AERs in response to increased ICP. We concluded from the results that the higher auditory centres are more susceptible to an increase in ICP to suppress the neural activities without apparent influence on the lower centres. A clinical test of ABR may be available to predict the prognosis of the auditory disorders.
用戊巴比妥钠麻醉猫，记录其初级皮层、内侧膝状体（MG）、下丘（IC）和耳蜗核（CN）的听觉诱发电位（AER），以研究颅内压（ICP）升高对不同听觉中枢水平神经活动的影响。通过向颅内空间注射盐溶液来升高ICP，并使用短纯音刺激激活听觉中枢。皮层反应（ACR）在ICP约为30 - 40 mmHg时开始幅度下降。随着ICP进一步升高，MG反应和IC反应的幅度依次下降。CN反应最具抗性，即使ACR和MG反应完全消失，它通常仍能保留。AER的恢复遵循压力升高解除后的相反顺序，即与AER下降顺序相反。当在短时间（如5至10分钟）的压力释放间隔后重复升高压力时，ACR的恢复变得慢得多，有时在ICP升高至100 mmHg以下释放后30 - 60分钟未观察到恢复。对AER随ICP升高而变化的起源进行了讨论。我们从结果中得出结论，较高的听觉中枢更容易受到ICP升高的影响，从而抑制神经活动，而对较低中枢没有明显影响。ABR的临床测试可能可用于预测听觉障碍的预后。
