Laurens-Thalen Elisabeth O, Wit Hero P, Segenhout Johannes M, Albers Frans W J
Department of Otorhinolaryngology, University Hospital Groningen, Groningen, The Netherlands.
Acta Otolaryngol. 2004 Aug;124(6):670-4. doi: 10.1080/00016480410017530.
The cochlear aqueduct connects the scala tympani to the subarachnoid space and is the main pressure equalization canal for the inner ear. Increases in inner ear volume and pressure are thought to cause clinical symptoms such as vertigo, tinnitus and fluctuating hearing loss. In this study the flow resistance of the cochlear aqueduct was determined and its relation with inner ear pressure was studied.
Inner ear pressure was measured in the scala tympani through the round window using a micropipette. Through a second micropipette, artificial perilymph was infused into, or withdrawn from, the scala tympani at various constant rates. From the infusion rate and the change in perilymphatic pressure during infusion the flow resistance of the cochlear aqueduct was calculated.
The flow resistance was found not to be constant but to depend on the position of the round window membrane and possibly on the magnitude and direction of fluid flow through the aqueduct. Measured flow resistance values were in the range 11-45 Pa s/nl. For very small flow values the flow resistance averaged over 6 animals was 21 Pa s/nl.
The flow resistance of the cochlear aqueduct is not a constant value. The cochlear aqueduct is a canal with dynamic properties and may play a role in the complicated process of inner ear pressure regulation.
蜗水管将鼓阶与蛛网膜下腔相连，是内耳的主要压力平衡通道。内耳容积和压力的增加被认为会导致眩晕、耳鸣和波动性听力损失等临床症状。在本研究中，测定了蜗水管的流动阻力，并研究了其与内耳压力的关系。
使用微量移液器通过圆窗在鼓阶测量内耳压力。通过第二个微量移液器，以不同的恒定速率向鼓阶注入或抽取人工外淋巴。根据注入速率和注入过程中外淋巴压力的变化计算蜗水管的流动阻力。
发现流动阻力并非恒定不变，而是取决于圆窗膜的位置，可能还取决于通过蜗水管的流体流动的大小和方向。测得的流动阻力值在11 - 45 Pa s/nl范围内。对于非常小的流量值，6只动物的平均流动阻力为21 Pa s/nl。
蜗水管的流动阻力不是一个恒定值。蜗水管是一个具有动态特性的通道，可能在内耳压力调节的复杂过程中起作用。
