Tsuchiya Y
Department of Otolaryngology, Tokyo Women's Medical College, Daini Hospital.
Nihon Jibiinkoka Gakkai Kaiho. 1995 Jun;98(6):1006-20. doi: 10.3950/jibiinkoka.98.1006.
To clarify the role of central velocity storage in caloric nystagmus, 20 normal subjects in the lateral recumbent position underwent recording and analysis using ENG and an infra-red video camera in darkness. The caloric stimulus was applied by pouring 10 ml of water at 20 degrees C for 20 seconds into the ear canal. After irrigation, each subject then turned to an ear-up or an ear-down lateral position. Ninety-nine percent of the rapid phases of the horizontal components were directed to the up-side ear with no relation to the irrigated ear. Sixty-six percent of the vertical components showed vertical nystagmus toward the lower eyelid, and the remaining 34% of the vertical components showed no vertical nystagmus. The direction of the torsional components was from the up-side ear to the leg with no relation to the irrigated ear. After the first phase, the nystagmus was more significantly reversed in the ear-up lateral position than in the ear-down lateral position (p < 0.01). The maximum slow-phase velocity of the first phase horizontal component and the nystagmus frequency of the first phase horizontal and vertical components were significantly smaller in the irrigated ear-up lateral position than in the ear-down lateral position (p < 0.01). The maximum slow-phase velocity of the first phase vertical component was also smaller in the ear-up lateral position (p < 0.05). However, the duration of the first phase vertical component revealed no difference between the two positions. These findings indicate that factors other than endolymph convection are involved in the first phase horizontal and vertical components. A role for central velocity storage in the vertical, components was suggested. When caloric nystagmus was analyzed as one response, including not only the horizontal component but also the vertical and torsional components, the possibility of otolithic involvement was suggested as one of the non-convection factors.
为阐明中枢速度存储在冷热性眼震中的作用，20名处于侧卧位的正常受试者在黑暗环境中使用眼震电图（ENG）和红外摄像机进行记录与分析。通过向耳道内灌注10毫升20摄氏度的水持续20秒来施加冷热刺激。灌注后，每位受试者随后转为耳朝上或耳朝下的侧卧位。水平成分快速相的99%指向朝上的耳朵，与灌注耳朵无关。垂直成分的66%表现为朝向较低眼睑的垂直眼震，其余34%的垂直成分未表现出垂直眼震。扭转成分的方向是从朝上的耳朵指向腿部，与灌注耳朵无关。在第一阶段后，耳朝上侧卧位的眼震反转比耳朝下侧卧位更显著（p<0.01）。第一阶段水平成分的最大慢相速度以及第一阶段水平和垂直成分的眼震频率在灌注耳朝上侧卧位时显著小于耳朝下侧卧位（p<0.01）。第一阶段垂直成分的最大慢相速度在耳朝上侧卧位时也较小（p<0.05）。然而，第一阶段垂直成分的持续时间在两个位置之间未显示出差异。这些发现表明，内淋巴对流以外的因素参与了第一阶段的水平和垂直成分。提示了中枢速度存储在垂直成分中的作用。当将冷热性眼震作为一种反应进行分析时，不仅包括水平成分，还包括垂直和扭转成分，提示耳石参与的可能性是其中一个非对流因素。
