Department of Neurology, University Hospital, Ludwig-Maximilians-University.
German Center for Vertigo and Balance Disorders, University Hospital, Ludwig-Maximilians-University.
Curr Opin Neurol. 2018 Feb;31(1):96-104. doi: 10.1097/WCO.0000000000000516.
The functional role of the vestibular system for multisensory orientation and sensorimotor control is reviewed with a special focus on hemispherical lateralization and its consequences for neurological disorders of higher cortical function.
The peripheral and central vestibular systems are bilaterally organized with ipsilateral and contralateral ascending pathways and two multisensory cortical networks in the right and left hemisphere. The vestibular cortical system shows a structural and functional lateralization with a dominance of the right hemisphere in right-handers and the left hemisphere in left-handers. Although the vestibular brainstem pathways are evenly distributed at lower pontine level, an increasing lateralization builds up because of an asymmetric number of pontine and mesencephalic crossing fibers from left to right in right-handers. This vestibular lateralization causes more frequent and more severe disorders of higher sensorimotor dysfunction in lesions of the right hemisphere such as in hemispatial neglect and the pusher syndrome.
There is evidence that multisensory higher vestibular functions including large-scale spatial orientation, spatial memory and navigation are dominated by the right temporo-parietal cortex. A beneficial result of lateralization of brain functions in healthy individuals is that it enables the individual to produce a global sensorimotor response even in case of a mismatch of the actual right and left sensory inputs. The consequence for neurology, however, is that lesions in the dominant hemisphere cause more frequently and more severe disorders such as the visuo-spatial hemineglect and the pusher syndrome.
本文重点探讨了前庭系统在多感觉定向和运动感觉控制中的功能作用，及其对半侧优势和对高级皮质功能神经障碍的影响。
外周和中枢前庭系统呈双侧分布，具有同侧和对侧上行通路以及右半球和左半球的两个多感觉皮质网络。前庭皮质系统具有结构和功能的偏侧化，右利手者以右侧优势为主，左利手者以左侧优势为主。尽管前庭脑桥通路在较低的脑桥水平均匀分布，但由于右利手者从左到右的脑桥和中脑交叉纤维数量不对称，偏侧化程度逐渐增加。这种前庭偏侧化导致右侧半球病变（如半空间忽略和推挤综合征）时，高级运动感觉功能障碍更频繁、更严重。
有证据表明，包括大尺度空间定向、空间记忆和导航在内的多感觉高级前庭功能主要由右颞顶皮质控制。健康个体大脑功能偏侧化的一个有益结果是，即使实际左右感觉输入不匹配，个体也能产生全局运动感觉反应。然而，对神经学的影响是，优势半球的病变导致更频繁和更严重的障碍，如视空间忽略和推挤综合征。
