PDF(Pubmed)
Abstract：
UNASSIGNED: We describe an uncharacteristic vestibular-ocular reflex (VOR) pattern, studied by video head impulse tests (VHIT) in patients suffering from unilateral isolated posterior semicircular canal (PSC) hypofunction. In these patients, we found an upward sliding of the eyes, followed by an oblique downward catch-up saccade during horizontal head impulse to the healthy side.
UNASSIGNED: We present a retrospective study of all VHIT exams presenting isolated PSC hypofunction between May 2020 and November 2022.
UNASSIGNED: We found 37 patients, which led to the discovery of such incongruent eye movement in 19 cases; their gain data are shown and compared to the remaining 18 cases in which such an anomaly was absent. A control group of 31 healthy subjects was recruited to define the reference criteria for VHIT gain values. The correlation between the amplitude of the vertical saccade and the relative functional imbalance of the vertical semicircular canals was studied.
UNASSIGNED: We have observed that in approximately half of the subjects with isolated CSP deficiency, there is a VOR anomaly. A possible pathophysiological explanation of the unbalanced effect of vertical semicircular canal stimulation of a labyrinth during horizontal head thrust toward the opposite side is proposed. The planar incongruity of the response of the VOR described here appears more evident at the onset of the CSP deficit. Current VHIT systems do not detect this incongruent eye reflex. They can lead to an error in gain evaluation (pseudo-deficit) of the lateral semicircular canal of the healthy side and problems in performing the test (trace rejected). In the future, software for VHIT should take into account the possibility of non-coplanar ocular responses to cephalic stimuli.
UNASSIGNED: We present a retrospective study of all VHIT exams presenting isolated PSC hypofunction between May 2020 and November 2022.
UNASSIGNED: We found 37 patients, which led to the discovery of such incongruent eye movement in 19 cases; their gain data are shown and compared to the remaining 18 cases in which such an anomaly was absent. A control group of 31 healthy subjects was recruited to define the reference criteria for VHIT gain values. The correlation between the amplitude of the vertical saccade and the relative functional imbalance of the vertical semicircular canals was studied.
UNASSIGNED: We have observed that in approximately half of the subjects with isolated CSP deficiency, there is a VOR anomaly. A possible pathophysiological explanation of the unbalanced effect of vertical semicircular canal stimulation of a labyrinth during horizontal head thrust toward the opposite side is proposed. The planar incongruity of the response of the VOR described here appears more evident at the onset of the CSP deficit. Current VHIT systems do not detect this incongruent eye reflex. They can lead to an error in gain evaluation (pseudo-deficit) of the lateral semicircular canal of the healthy side and problems in performing the test (trace rejected). In the future, software for VHIT should take into account the possibility of non-coplanar ocular responses to cephalic stimuli.
摘要：
■我们描述了一种无特征的前庭眼反射（VOR）模式，通过视频头脉冲测试（VHIT）研究患有单侧孤立性后半规管（PSC）功能减退的患者。在这些患者中,我们发现眼睛向上滑动，然后在水平头部冲向健康侧的过程中进行倾斜的向下追赶扫视。
■我们对2020年5月至2022年11月期间出现孤立的PSC功能减退的所有VHIT考试进行了回顾性研究。
■我们发现37名患者,这导致在19例中发现了这种不一致的眼球运动；显示了他们的增益数据，并将其与不存在这种异常的其余18例进行了比较。招募31名健康受试者的对照组来定义VHIT增益值的参考标准。研究了垂直扫视的幅度与垂直半规管的相对功能失衡之间的相关性。
■我们观察到，在大约一半的孤立性CSP缺乏的受试者中，有一个VOR异常。提出了一种可能的病理生理学解释，可以解释在水平头部向另一侧推力过程中迷宫的垂直半规管刺激的不平衡作用。在CSP缺陷开始时，此处描述的VOR响应的平面不一致显得更加明显。当前的VHIT系统无法检测到这种不一致的眼睛反射。它们可能导致健康侧的外侧半规管的增益评估错误（伪赤字）和执行测试的问题（痕迹被拒绝）。在未来,VHIT软件应考虑对头部刺激的非共面眼反应的可能性.
■我们对2020年5月至2022年11月期间出现孤立的PSC功能减退的所有VHIT考试进行了回顾性研究。
■我们发现37名患者,这导致在19例中发现了这种不一致的眼球运动；显示了他们的增益数据，并将其与不存在这种异常的其余18例进行了比较。招募31名健康受试者的对照组来定义VHIT增益值的参考标准。研究了垂直扫视的幅度与垂直半规管的相对功能失衡之间的相关性。
■我们观察到，在大约一半的孤立性CSP缺乏的受试者中，有一个VOR异常。提出了一种可能的病理生理学解释，可以解释在水平头部向另一侧推力过程中迷宫的垂直半规管刺激的不平衡作用。在CSP缺陷开始时，此处描述的VOR响应的平面不一致显得更加明显。当前的VHIT系统无法检测到这种不一致的眼睛反射。它们可能导致健康侧的外侧半规管的增益评估错误（伪赤字）和执行测试的问题（痕迹被拒绝）。在未来,VHIT软件应考虑对头部刺激的非共面眼反应的可能性.
