From the Research Administration Team (Hyo-Jung Kim), Seoul National University Bundang Hospital, Seongnam, Korea; Department of Neurology (Hyun-Jae Kim), Chungbuk National University Hospital, Cheongju, Korea; Dizziness Center (J.-H.L., J.-S.K.), Clinical Neuroscience Center, Seoul National University Bundang Hospital, Seongnam, Korea; and Department of Neurology (J.-S.K.), Seoul National University College of Medicine, Korea.
Neurology. 2023 Jan 3;100(1):43-46. doi: 10.1212/WNL.0000000000201466. Epub 2022 Oct 3.
Vibratory stimulation of the sternocleidomastoid muscles or the skull may enhance vestibular asymmetry and evoke nystagmus. We report prominent downbeating vibration-induced nystagmus (VIN) in a patient with paraneoplastic cerebellar degeneration due to cervical cancer with positive serum anti-Ri antibody. A 47-year-old woman developed spontaneous upbeat nystagmus present with and without visual fixation. Nystagmus decreased during lateral and upward gaze. Downbeat nystagmus emerged during convergence and after horizontal head shaking for approximately 15 seconds and during vibratory stimulation of the mastoids and forehead. Additional findings included positional downbeat nystagmus, impaired smooth pursuit, hypermetric horizontal saccades, and truncal ataxia. During video-head impulse tests, the gains of the vestibulo-ocular reflex (VOR) were normal for both horizontal semicircular canals but increased for both anterior canals and decreased for both posterior canals. Horizontal head impulses produced cross-coupled downward corrective saccades. Given the asymmetric vertical VOR, downbeat VIN observed in our patient may be ascribed to enhanced upward bias of the VOR due to vestibulocerebellar dysfunction during the vibratory stimuli. Vibration-induced downbeat nystagmus should be added to the list of central vestibular signs and is likely due to cerebellar dysfunction.
胸锁乳突肌或颅骨的振动刺激可能会增强前庭不对称，并引起眼球震颤。我们报告了一名因宫颈癌而出现副肿瘤性小脑变性的患者，其血清抗 Ri 抗体阳性，表现为明显的向下摆动振动诱导性眼球震颤（VIN）。一名 47 岁女性出现自发性上跳眼球震颤，伴有或不伴有视觉固视。眼球震颤在侧视和上视时减少。在水平头部晃动约 15 秒后、在乳突和前额振动刺激时出现向下摆动眼球震颤。其他发现包括位置性下跳眼球震颤、平滑追踪障碍、超距水平扫视和躯干共济失调。在视频头脉冲测试中，水平半规管的前庭眼反射（VOR）增益正常，但前半规管的增益增加，后半规管的增益降低。水平头部脉冲产生交叉耦合向下校正扫视。鉴于不对称的垂直 VOR，我们患者观察到的向下摆动 VIN 可能归因于振动刺激期间前庭小脑功能障碍导致 VOR 向上偏倚增强。振动诱导的向下摆动眼球震颤应添加到中枢前庭体征列表中，可能是由于小脑功能障碍引起的。
