Saarland University, Clinical Neuropsychology Unit, Saarbruecken, Germany; International Research Training Group 1457 "Adaptive Minds", Saarbruecken, Germany.
Schoen Clinic Bad Aibling, Department of Neuropsychology, Germany.
Neuropsychologia. 2011 Apr;49(5):1219-1225. doi: 10.1016/j.neuropsychologia.2011.02.046. Epub 2011 Mar 1.
Patients with right hemisphere lesions often show left spatial neglect and the typical rightward deviation in horizontal line bisection. Previous studies have shown that sensory stimulation modulates line bisection. A less well-known but promising sensory stimulation method is galvanic vestibular stimulation (GVS). This non-invasive technique leads to activation of the vestibular cortices and adjacent cortical areas in the temporo-parietal cortex via polarization effects of the vestibular nerves. This is accomplished by application of weak direct currents, delivered by two electrodes attached to the mastoids. Despite the relative benefits of GVS its effects on line bisection have not yet been studied in neglect patients. Thus, the present study investigated the impact of GVS on performance in a modified line bisection task in right-brain damaged patients with versus without leftsided visual neglect. In neglect patients, but not in control patients, left-cathodal and right-cathodal GVS significantly reduced the rightward line bisection error as compared to Baseline (without GVS) and sham stimulation. A larger decrease of the rightward line bisection error was observed during right-cathodal GVS. Sham stimulation showed no specific effects on line bisection. The beneficial effects of GVS might be due to activation of preserved structures of the lesioned right posterior parietal cortex which is known to be involved in line bisection.
右侧大脑损伤的患者常表现出左侧空间忽略，以及水平直线二等分的典型向右偏差。既往研究表明，感觉刺激可调节直线二等分。一种不太知名但很有前途的感觉刺激方法是电前庭刺激（GVS）。该非侵入性技术通过前庭神经的极化作用，导致前庭皮质和颞顶皮质中相邻皮质区域的激活。通过将两个电极贴在乳突上来实现这一点。尽管 GVS 具有相对优势，但它对忽视患者直线二等分的影响尚未得到研究。因此，本研究调查了 GVS 在右侧大脑损伤患者和无左侧视觉忽视患者的改良直线二等分任务中的影响。在忽视患者中，但在对照组患者中没有，与基线（无 GVS）和假刺激相比，左阴极和右阴极 GVS 显著降低了右侧直线二等分错误。在右阴极 GVS 期间观察到右侧直线二等分错误的更大降低。假刺激对直线二等分没有特定影响。GVS 的有益效果可能归因于损伤的右侧后顶叶皮层的保留结构的激活，该结构已知参与直线二等分。
