Department of Neurology, Aerospace Center Hospital, Peking University Aerospace School of Clinical Medicine, Beijing, 100049, People's Republic of China.
Department of Radiology, Aerospace Center Hospital, Peking University Aerospace School of Clinical Medicine, Beijing, 100049, People's Republic of China.
Brain Imaging Behav. 2020 Dec;14(6):2176-2186. doi: 10.1007/s11682-019-00168-7.
Persistent postural-perceptual dizziness (PPPD) is a functional vestibular disorder, and is the most common cause of chronic vestibular syndrome. However, the pathogenesis of PPPD is currently unclear. This study aimed to analyze the changes of brain spontaneous functional activities in PPPD patients during the resting state, and to explore the underlying pathogenesis of PPPD, particularly the abnormal integration of visual and vestibular information. Ten PPPD patients and 10 healthy controls were enrolled from January to June 2018, and baseline data were collected from all subjects. Videonystagmography (VNG), the vestibular caloric test, the video head impulse test (vHIT) and vestibular evoked myogenic potentials (VEMPs) were measured to exclude peripheral vestibular lesions. Functional MRI (fMRI) was conducted in PPPD patients and healthy controls. The amplitude of low frequency fluctuation (ALFF) and regional homogeneity (ReHo), and functional connectivity were calculated to explore changes in brain spontaneous functional activity during the resting state. Compared with healthy controls, ALFF and ReHo values in the right precuneus and cuneus were significantly lower in PPPD patients (both P < 0.05). Further seed-based functional connectivity analysis showed decreased functional connectivity between precuneus, cuneus and left precentral gyrus (P < 0.05). Our findings suggest that the spontaneous functional activity of cuneus and precuneus in PPPD patients were altered, potentially leading to abnormal integration of visual and vestibular information. Weakened functional connectivity between the precuneus and the precentral gyrus may be associated with aggravated symptoms during upright posture, active or passive movements.
持续性姿势-感知性头晕（PPPD）是一种功能性前庭障碍，是慢性前庭综合征最常见的原因。然而，目前 PPPD 的发病机制尚不清楚。本研究旨在分析 PPPD 患者在静息状态下大脑自发性功能活动的变化，并探讨 PPPD 的潜在发病机制，特别是视觉和前庭信息的异常整合。2018 年 1 月至 6 月，我们从 PPPD 患者和健康对照者中招募了 10 名 PPPD 患者和 10 名健康对照者，并从所有受试者中收集了基线数据。进行视频眼震图（VNG）、前庭冷热水试验、视频头脉冲试验（vHIT）和前庭诱发肌源性电位（VEMPs）检查，以排除外周前庭病变。对 PPPD 患者和健康对照者进行功能磁共振成像（fMRI）检查。计算低频振幅（ALFF）和局部一致性（ReHo）以及功能连接，以探讨静息状态下大脑自发性功能活动的变化。与健康对照组相比，PPPD 患者右侧楔前叶和楔叶的 ALFF 和 ReHo 值明显降低（均 P<0.05）。进一步的种子点功能连接分析显示，楔前叶和楔叶与左侧中央前回之间的功能连接减弱（P<0.05）。我们的研究结果表明，PPPD 患者楔叶和楔前叶的自发性功能活动发生改变，可能导致视觉和前庭信息的异常整合。楔前叶与中央前回之间功能连接减弱可能与直立位、主动或被动运动时症状加重有关。
