On the vertigo due to static magnetic fields.
On the vertigo due to static magnetic fields.
复制标题
DOI：
10.1371/journal.pone.0078748
复制
发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Day BL
中科院分区：
文献类型：
--
作者：
Mian OS;Li Y;Antunes A;Glover PM;Day BL
有时在MRI扫描仪内或周围会出现眩晕。已经提出了涉及通过在磁场或磁场空间梯度中的运动来刺激前庭系统的机制。然而，最近的研究表明，前庭依赖性眼球震颤是诱发时，稳定在均匀的静态磁场。所提出的机制涉及洛伦兹力作用于内淋巴，使半规管（SCC）杯偏转。为了研究眩晕是否由类似的机制引起，我们记录了仰卧位健康成年人（n = 25）在被推入MRI扫描仪的7T静态场时被剥夺视觉的眩晕和2D眼球运动的定性和定量方面。 暴露是可变的，包括在7T下长达135 s的静止。眼球震颤主要是水平的，在长时间暴露期间持续存在，部分下降，并在退出时逆转。头朝上的主要眩晕感觉是在水平面上旋转（85%的发生率），并且参与者的方向一致。随着头部在偏航中转动90度，感知没有转换成等效的垂直平面旋转，这表明感知的上下文依赖性。在长时间曝光期间，错觉旋转平均持续50 s，其中包括42 s，而在7T静止。在戒断后，知觉重新出现并逆转，平均持续30秒。眼震和知觉的起始视野显著相关（p<0.05）。虽然知觉不像眼球震颤那样持久，但这是连续SSC刺激的已知特征。这些观察结果，以及论文中的其他观察结果，与磁场诱发的眩晕和眼球震颤有着共同的机制是一致的。根据这种解释，从场退出时的反应衰减和逆转是由于对连续前庭输入的适应。虽然这项研究并没有完全排除可能的机制，涉及短暂的前庭刺激在运动的孔，我们认为这些是不太可能的。
Vertigo is sometimes experienced in and around MRI scanners. Mechanisms involving stimulation of the vestibular system by movement in magnetic fields or magnetic field spatial gradients have been proposed. However, it was recently shown that vestibular-dependent ocular nystagmus is evoked when stationary in homogenous static magnetic fields. The proposed mechanism involves Lorentz forces acting on endolymph to deflect semicircular canal (SCC) cupulae. To investigate whether vertigo arises from a similar mechanism we recorded qualitative and quantitative aspects of vertigo and 2D eye movements from supine healthy adults (n = 25) deprived of vision while pushed into the 7T static field of an MRI scanner. Exposures were variable and included up to 135s stationary at 7T. Nystagmus was mainly horizontal, persisted during long-exposures with partial decline, and reversed upon withdrawal. The dominant vertiginous perception with the head facing up was rotation in the horizontal plane (85% incidence) with a consistent direction across participants. With the head turned 90 degrees in yaw the perception did not transform into equivalent vertical plane rotation, indicating a context-dependency of the perception. During long exposures, illusory rotation lasted on average 50 s, including 42 s whilst stationary at 7T. Upon withdrawal, perception re-emerged and reversed, lasting on average 30 s. Onset fields for nystagmus and perception were significantly correlated (p<.05). Although perception did not persist as long as nystagmus, this is a known feature of continuous SSC stimulation. These observations, and others in the paper, are compatible with magnetic-field evoked-vertigo and nystagmus sharing a common mechanism. With this interpretation, response decay and reversal upon withdrawal from the field, are due to adaptation to continuous vestibular input. Although the study does not entirely exclude the possibility of mechanisms involving transient vestibular stimulation during movement in and out of the bore, we argue these are less likely.
登录
查看更多内容
影响因子：
2.5
作者：
GOLDBERG, JM;FERNANDEZ, C
通讯作者：
FERNANDEZ, C
影响因子：
--
作者：
BROWN, JH
通讯作者：
BROWN, JH
影响因子：
3.8
作者：
SCHENCK, JF;DUMOULIN, CL;MCDOUGALL, IL
通讯作者：
MCDOUGALL, IL
影响因子：
4.4
作者：
Cavin, Ian D.;Glover, Paul M.;Gowland, Penny A.
通讯作者：
Gowland, Penny A.
影响因子：
--
作者：
CLARK, B;STEWART, JD
通讯作者：
STEWART, JD