Department of Neurology, Baskent University, Medical School, Adana Research Center, Adana, Turkey.
Eur J Neurol. 2009 Dec;16(12):1265-77. doi: 10.1111/j.1468-1331.2009.02779.x. Epub 2009 Sep 1.
Eye movements bring visual stimuli to the fovea and also maintain foveal fixation on a moving target and during head movements. These movements are performed by the ocular motor system that consists of ocular motor nerves and nuclei in the brainstem originating in the cerebral cortex, cerebellum, vestibular structures, and the extraocular muscles. The ocular motor system is divided according to anatomic location into infranuclear, nuclear, internuclear, and supranuclear components. It is important to distinguish supranuclear and internuclear from nuclear and infranuclear disturbances affecting cranial nerves III, IV, and VI, because the disturbances are of highly varied causes and present different clinical pictures. Internuclear ophthalmoplegia is due to a lesion of the medial longitudinal fasciculus, caused by multiple sclerosis in younger patients, particularly when the ophthalmoplegia is bilateral, and usually of vascular origin in the elderly. Eye movement abnormalities of supranuclear origin are characterized by gaze palsies, tonic gaze deviation, saccadic and smooth pursuit disorders, vergence abnormalities, nystagmus, and ocular oscillations. Supranuclear disorders result from lesions above the level of the ocular motor nerve nuclei. If oculocephalic maneuvers move the eyes appropriately, the lesion causing the gaze palsy is supranuclear. Supranuclear disorders account for almost 10% of all patients with disorders of eye movements.
眼球运动将视觉刺激物带到中央凹，并在头部运动期间保持中央凹对移动目标的固定。这些运动是由眼动系统完成的，该系统由起源于大脑皮层、小脑、前庭结构和眼外肌的脑干中的眼运动神经和核组成。眼动系统根据解剖位置分为核下、核内、核间和核上成分。区分核上和核间与影响第三、第四和第六脑神经的核内和核下障碍非常重要，因为这些障碍的原因多种多样，表现出不同的临床特征。核间眼肌麻痹是由于内侧纵束的病变引起的，在年轻患者中，尤其是当眼肌麻痹为双侧时，病变多由多发性硬化引起，而在老年人中，病变通常由血管引起。核上起源的眼球运动异常的特征是凝视麻痹、紧张性眼球偏斜、扫视和平滑追踪障碍、聚散异常、眼球震颤和眼动性震颤。核上障碍是由眼球运动神经核以上水平的病变引起的。如果眼球运动检查能够适当移动眼球，则导致凝视麻痹的病变是核上的。核上障碍占所有眼球运动障碍患者的近 10%。
