From the Department of Neurology (S.Y.C., J.-Y.J., K.-D.C.), Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan; Department of Neurology (E.H.O., J.-H.C.), Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital; Department of Neurology (J.Y.P.), Ulsan University Medical School, Ulsan University Hospital; and Department of Neurology (S.-H.L.), Chonnam National University Medical School, Chonnam National University Hospital Neurology Department, Seoul, Korea.
Neurology. 2018 Sep 11;91(11):e1053-e1057. doi: 10.1212/WNL.0000000000006167. Epub 2018 Aug 10.
To determine the prevalence of central lesions in persistent geotropic positional nystagmus, and characteristics and anatomical substrates of the nystagmus in cerebellar lesions.
We prospectively recruited 58 patients with persistent geotropic positional nystagmus at the Dizziness Clinic of Pusan National University Hospital. Seven patients with unilateral cerebellar lesions were subjected to analysis of clinical characteristics, oculographic data, and MRI lesions. For comparison, we studied 37 cases of peripheral persistent geotropic positional nystagmus.
The prevalence of central lesions in persistent geotropic positional nystagmus was 12% (7/58). Persistent geotropic positional nystagmus in cerebellar lesions was mostly asymmetrical. Horizontal nystagmus changed in direction during the bow-and-lean test with null positions. All patients showed impaired horizontal smooth pursuit bilaterally, and 3 of them also had positional downbeat nystagmus. The peak intensity and asymmetry of persistent geotropic positional nystagmus did not differ between central and peripheral groups ( > 0.05), while there was a difference in the maxima. Lesion overlays revealed that damage to the cerebellar tonsil was responsible for the generation of persistent geotropic positional nystagmus.
Although persistent geotropic positional nystagmus in cerebellar lesions shares the characteristics of nystagmus measures with peripheral cases, accompanying central oculomotor signs can aid in differentiation. In tonsillar lesions, compensatory rotational feedback due to erroneous estimation of the direction of gravity may generate constant horizontal geotropic positional nystagmus.
确定位置性持久性向地性眼球震颤中中枢病变的发生率，以及小脑病变中眼球震颤的特征和解剖学基础。
我们前瞻性地招募了 58 名在釜山国立大学医院头晕诊所就诊的位置性持久性向地性眼球震颤患者。对 7 例单侧小脑病变患者进行了临床特征、眼震图数据和 MRI 病变分析。为了比较，我们研究了 37 例周围性位置性持久性向地性眼球震颤。
位置性持久性向地性眼球震颤中中枢病变的发生率为 12%（7/58）。小脑病变引起的位置性持久性向地性眼球震颤多为不对称性。在头倾-倾头试验中，水平眼球震颤的方向随零位而改变。所有患者双侧水平平滑追踪均受损，其中 3 例还存在位置性下跳性眼球震颤。位置性持久性向地性眼球震颤的峰值强度和不对称性在中枢和周围组之间没有差异（>0.05），但最大值有差异。病变叠加显示，小脑扁桃体的损伤是产生位置性持久性向地性眼球震颤的原因。
尽管小脑病变引起的位置性持久性向地性眼球震颤在眼球震颤测量方面与周围性病例具有相同的特征，但伴随的中枢眼球运动征象有助于鉴别。在扁桃体病变中，由于对重力方向的错误估计导致的代偿性旋转反馈可能产生恒定的水平向地性位置性眼球震颤。
