Neuro-Otology Unit, Division of Experimental Medicine, Centre of Neuroscience, Charing Cross Hospital, Imperial College London, London W6 8RF, UK.
J Neurol. 2012 Jun;259(6):1117-24. doi: 10.1007/s00415-011-6311-7. Epub 2011 Nov 24.
The increased visual dependence noted in some vestibular patients may be secondary to their vertigo. We examine whether a single, brief vertigo attack, such as in benign paroxysmal positional vertigo (BPPV), modifies visual dependency. Visual dependency was measured before and after the Hallpike manoeuvre with (a) the Rod and Frame and the Rod and Disc techniques whilst seated and (b) the postural sway induced by visual roll-motion stimulation. Three subject groups were studied: 20 patients with BPPV (history and positive Hallpike manoeuvre; PosH group), 20 control patients (history of BPPV but negative Hallpike manoeuvre; NegH group) and 20 normal controls. Our findings show that while both patient groups showed enhanced visual dependency, the PosH and the normal control group decreased visual dependency on repetition of the visual tasks after the Hallpike manoeuvre. NegH patients differed from PosH patients in that their high visual dependency did not diminish on repetition of the visual stimuli; they scored higher on the situational characteristic questionnaire ('visual vertigo' symptoms) and showed higher incidence of migraine. We conclude that long term vestibular symptoms increase visual dependence but a single BPPV attack does not increase it further. Repetitive visual motion stimulation induces adaptation in visual dependence in peripheral vestibular disorders such as BPPV. A positional form of vestibular migraine may underlie the symptoms of some patients with a history of BPPV but negative Hallpike manoeuvre. The finding that they have non adaptable increased visual dependency may explain visuo-vestibular symptoms in this group and, perhaps more widely, in patients with migraine.
一些前庭患者的视觉依赖性增加可能是眩晕的继发症状。我们研究了单次短暂的眩晕发作（如良性阵发性位置性眩晕，BPPV）是否会改变视觉依赖性。在进行 Hallpike 手法前后，我们使用（a）Rod 和 Frame 以及 Rod 和 Disc 技术，同时坐在座位上，以及（b）视觉滚动运动刺激引起的姿势摆动，测量了视觉依赖性。我们研究了三组受试者：20 名 BPPV 患者（有病史和阳性 Hallpike 手法；PosH 组）、20 名对照患者（有 BPPV 病史但阴性 Hallpike 手法；NegH 组）和 20 名正常对照。我们的发现表明，虽然两组患者都表现出增强的视觉依赖性，但 PosH 组和正常对照组在进行 Hallpike 手法后，视觉任务重复时，视觉依赖性降低。NegH 患者与 PosH 患者不同，他们的高视觉依赖性在重复视觉刺激时并未减弱；他们在情境特征问卷（“视觉眩晕”症状）上的得分更高，偏头痛的发生率也更高。我们得出结论，长期的前庭症状会增加视觉依赖性，但单次 BPPV 发作不会进一步增加。在 BPPV 等外周前庭障碍中，重复的视觉运动刺激会引起视觉依赖性的适应。一种位置性前庭性偏头痛可能是一些有 BPPV 病史但阴性 Hallpike 手法患者症状的基础。他们具有不可适应的增加的视觉依赖性的发现可能解释了该组患者以及可能更广泛的偏头痛患者的视-前庭症状。
