Kaibe Shinobu, Okita Manabu, Kaba Hideto
Department of Rehabilitation, Kamojima Hospital, Yoshinogawa, Tokushima 776-8588, Japan; Department of Physiology, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan.
Department of Physiology, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan; Department of Rehabilitation, Atago Hospital, Kochi 780-0051, Japan.
J Clin Neurosci. 2017 Jul;41:41-45. doi: 10.1016/j.jocn.2017.01.003. Epub 2017 Feb 9.
Unilateral spatial neglect is a common neurological syndrome following predominantly right hemisphere damage, and is characterized by a failure to perceive and report stimuli in the contralesional side of space. To test the reference shift hypothesis that contralesional spatial neglect in right-brain-damaged patients is attributed to a rightward deviation of the egocentric reference frame, we measured the final angular position to which controls and left-side neglect patients actively turned their head toward the left in response to a verbal instruction given from each of three locations-right, left, and front-in two conditions, with and without visual feedback. When neglect patients were asked to "look straight ahead", they deviated about 30° toward the right in the eyes-open condition. However, the rightward deviation was markedly reduced in the eyes-closed condition. Regardless of visual feedback, there was no significant difference between controls and neglect patients in the final angular position of active head rotation when the verbal instruction came from the subject's left or front side; however, the final angular position was significantly smaller in the neglect patients than in the controls when the verbal instruction was given from the right. These results support the contention that cervico-vestibular stimulation during active head rotation restores spatial remapping and sensori-motor correlations and so improves neglect without affecting the position of the egocentric reference; however, once left-side neglect patients respond to verbal instruction from the right side, they are unable to disengage attention from the hemispace, and the performance of head rotation is disturbed.
单侧空间忽视是一种常见的神经综合征，主要发生在右侧半球损伤后，其特征是无法感知和报告空间对侧的刺激。为了验证右脑损伤患者的对侧空间忽视归因于自我中心参考框架向右偏移的参考转移假说，我们测量了对照组和左侧忽视患者在两种情况下（有视觉反馈和无视觉反馈），从右侧、左侧和前方三个位置之一发出的口头指令下，主动向左转头的最终角度位置。当要求忽视患者“直视前方”时，在睁眼条件下他们向右偏离约30°。然而，在闭眼条件下，向右的偏差明显减小。无论有无视觉反馈，当口头指令来自受试者左侧或前方时，对照组和忽视患者在主动转头的最终角度位置上没有显著差异；然而，当从右侧发出口头指令时，忽视患者的最终角度位置明显小于对照组。这些结果支持了这样的观点，即主动转头过程中的颈前庭刺激可恢复空间重新映射和感觉运动相关性，从而改善忽视症状，而不影响自我中心参考的位置；然而，一旦左侧忽视患者对来自右侧的口头指令做出反应，他们就无法将注意力从半侧空间中脱离，转头表现会受到干扰。
