Rodriguez Belén, Pantano Lynn, Nef Tobias, Müri René M, Z'Graggen Werner J
Department of Neurosurgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
Eur J Neurol. 2025 Jan;32(1):e16507. doi: 10.1111/ene.16507. Epub 2024 Oct 27.
Patients with postural tachycardia syndrome report position-dependent visual symptoms. Despite their impact on daily life, these symptoms have remained largely unexplored in research. The aim of this study was to investigate the nature of visual symptoms in postural tachycardia syndrome and possible underlying pathophysiological mechanisms.
Fifteen patients with postural tachycardia syndrome and 15 healthy controls were included in the study. Through a comprehensive array of measurements, including haemodynamics, subjective symptom assessments, eye movement tracking and pupil diameter analysis, participants were assessed during free image exploration in both supine and 60° head-up tilt positions.
During head-up tilt, patients showed a decreased number and duration of fixations, as well as a decreased number, peak velocity and amplitude of saccades compared to the supine position and the control group. This reduction in visual exploration occurred primarily in the peripheral field of view and coincided with the occurrence of subjective visual symptoms. No significant differences in the saccade main sequence were observed between the two groups in either body position.
Patients with postural tachycardia syndrome have a reduced exploration of the peripheral field of view when in an upright body position, potentially leading to tunnel vision. Since the normality of the saccade main sequence in patients combined with the focus on the centre of the field of view and the lower saccade amplitudes points to an intact brainstem function, the decrease in peripheral visual exploration may be attributed to a position-dependent dysfunction of the frontal eye field.
体位性心动过速综合征患者报告有与体位相关的视觉症状。尽管这些症状对日常生活有影响，但在研究中它们在很大程度上仍未得到充分探索。本研究的目的是调查体位性心动过速综合征中视觉症状的本质以及可能的潜在病理生理机制。
本研究纳入了15名体位性心动过速综合征患者和15名健康对照者。通过一系列综合测量，包括血流动力学、主观症状评估、眼动追踪和瞳孔直径分析，在仰卧位和头高位倾斜60°时进行自由图像探索期间对参与者进行评估。
与仰卧位和对照组相比，在头高位倾斜时，患者的注视次数和持续时间减少，扫视的次数、峰值速度和幅度也减少。这种视觉探索的减少主要发生在周边视野，并且与主观视觉症状的出现同时发生。在两种体位下，两组之间扫视主序列均未观察到显著差异。
体位性心动过速综合征患者在直立体位时对周边视野的探索减少，可能导致管状视野。由于患者扫视主序列正常，同时关注视野中心且扫视幅度较小，表明脑干功能完好，周边视觉探索的减少可能归因于额叶眼区的体位依赖性功能障碍。
