inAmind Laboratory, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester LE1 7RH, UK.
inAmind Laboratory, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester LE1 7RH, UK; Balance Clinic, E.N.T Department, Leicester Royal Infirmary, Leicester LE1 5WW, UK.
J Neurol Sci. 2023 May 15;448:120617. doi: 10.1016/j.jns.2023.120617. Epub 2023 Mar 22.
Patients with vestibular dysfunctions often experience visual-induced symptoms. Here we asked whether such visual dependence can be related to alterations in visual conscious awareness in these patients.
To measure visual conscious awareness, we used the effect of motion-induced blindness (MIB,) in which the perceptual awareness of the visual stimulus alternates despite its unchanged physical characteristics. In this phenomenon, a salient visual target spontaneously disappears and subsequently reappears from visual perception when presented against a moving visual background. The number of perceptual switches during the experience of the MIB stimulus was measured for 120 s in 15 healthy controls, 15 patients with vestibular migraine, 15 patients with benign positional paroxysmal vertigo (BPPV) and 15 with migraine without vestibular symptoms.
Patients with vestibular dysfunctions (i.e., both vestibular migraine and BPPV) exhibited increased perceptual fluctuations during MIB compared to healthy controls and migraine patients without vertigo. In VM patients, those with more severe symptoms exhibited higher fluctuations of visual awareness (i.e., positive correlation), whereas, in BPPV patients, those with more severe symptoms had lower fluctuations of visual awareness (i.e., negative correlation).
Taken together, these findings show that fluctuations of visual awareness are linked to the severity of visual-induced symptoms in patients with vestibular dysfunctions, and distinct pathophysiological mechanisms may mediate visual vertigo in peripheral versus central vestibular dysfunctions.
患有前庭功能障碍的患者常出现视觉诱发的症状。在此，我们想探讨这种视觉依赖性是否与这些患者的视觉意识改变有关。
为了测量视觉意识，我们使用了运动诱发性盲（MIB）的效果，即尽管视觉刺激的物理特征保持不变，但视觉感知会交替出现。在这种现象中，一个显著的视觉目标在呈现于运动视觉背景时会自发地从视觉感知中消失，随后又重新出现。我们在 120 秒内测量了 15 名健康对照者、15 名前庭性偏头痛患者、15 名良性阵发性位置性眩晕（BPPV）患者和 15 名无前庭症状的偏头痛患者在经历 MIB 刺激时的感知转换次数。
与健康对照组和无眩晕偏头痛患者相比，前庭功能障碍患者（即前庭性偏头痛和 BPPV 患者）在 MIB 期间表现出更高的感知波动。在 VM 患者中，症状更严重的患者表现出更高的视觉意识波动（即正相关），而在 BPPV 患者中，症状更严重的患者表现出更低的视觉意识波动（即负相关）。
综上所述，这些发现表明，视觉意识的波动与前庭功能障碍患者视觉诱发症状的严重程度有关，外周性和中枢性前庭功能障碍的视觉眩晕可能存在不同的病理生理机制。
