Indovina Iole, Passamonti Luca, Mucci Viviana, Chiarella Giuseppe, Lacquaniti Francesco, Staab Jeffrey P
Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, 98125 Messina, Italy.
Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, 00179 Rome, Italy.
J Clin Med. 2021 Sep 21;10(18):4274. doi: 10.3390/jcm10184274.
Persistent postural-perceptual dizziness (PPPD), defined in 2017, is a vestibular disorder characterized by chronic dizziness that is exacerbated by upright posture and exposure to complex visual stimuli. This review focused on recent neuroimaging studies that explored the pathophysiological mechanisms underlying PPPD and three conditions that predated it. The emerging picture is that local activity and functional connectivity in multimodal vestibular cortical areas are decreased in PPPD, which is potentially related to structural abnormalities (e.g., reductions in cortical folding and grey-matter volume). Additionally, connectivity between the prefrontal cortex, which regulates attentional and emotional responses, and primary visual and motor regions appears to be increased in PPPD. These results complement physiological and psychological data identifying hypervigilant postural control and visual dependence in patients with PPPD, supporting the hypothesis that PPPD arises from shifts in interactions among visuo-vestibular, sensorimotor, and emotional networks that overweigh visual over vestibular inputs and increase the effects of anxiety-related mechanisms on locomotor control and spatial orientation.
持续性姿势-感知性头晕（PPPD）于2017年被定义，是一种前庭障碍，其特征为慢性头晕，在直立姿势和暴露于复杂视觉刺激时会加重。本综述聚焦于近期的神经影像学研究，这些研究探索了PPPD及其之前的三种情况的病理生理机制。新出现的情况是，PPPD患者多模式前庭皮质区域的局部活动和功能连接减少，这可能与结构异常有关（例如，皮质折叠和灰质体积减少）。此外，在PPPD患者中，调节注意力和情绪反应的前额叶皮质与初级视觉和运动区域之间的连接似乎增加。这些结果补充了生理和心理数据，这些数据表明PPPD患者存在过度警觉的姿势控制和视觉依赖，支持了PPPD源于视觉-前庭、感觉运动和情绪网络之间相互作用的转变这一假说，这种转变使视觉输入超过前庭输入，并增加了焦虑相关机制对运动控制和空间定向的影响。
