Laboratory of Vestibular NeuroAdaptation (M.C.S.), Department of Otolaryngology Head and Neck Surgery, and Department of Physical Medicine and Rehabilitation (M.C.S.), Johns Hopkins School of Medicine, Baltimore, Maryland; UPMC Centers for Rehab Services (P.M.D.), Jordan Center for Balance Disorders, Pittsburgh, Pennsylvania; Departments of Physical Therapy and Otolaryngology (S.L.W.), University of Pittsburgh, Pennsylvania; and Rehabilitation Research Chair (S.L.W.), King Saud University, Riyadh, Kingdom of Saudi Arabia.
J Neurol Phys Ther. 2017 Jul;41(3):182-186. doi: 10.1097/NPT.0000000000000191.
Deciphering the cause for a persistent, direction-changing geotropic nystagmus can be difficult. Migraine and light cupula are two possible causes, though can be confused with benign paroxysmal positional vertigo (BPPV) affecting the horizontal semicircular canal. In migraine, the persistent geotropic nystagmus tends to be slow; in light cupula, the nystagmus has been illustrated to beat in the direction opposite that of prone positioning.
Here we describe a patient with initial occurrence then recurrence of a high velocity (≥30 deg/sec), persistent direction-changing geotropic nystagmus and vertigo with an intensity variable based on head position, which was difficult to manage. This patient did not have migraine. The case presented uniquely as it was unlikely due to canalithiasis of the horizontal semicircular canal yet the presentation was not clearly related to the light cupula phenomena either.
In this case, the physical therapist attempted to use the barbeque roll canalith repositioning maneuver (CRM) even though the direction-changing geotropic nystagmus was persistent. The nystagmus did not resolve during the clinic visit.
The persistent, high velocity geotropic nystagmus resolved within 1 week, however, this resolution was likely spontaneous and not due to the CRM intervention. Our case suggests that physical therapists assessing persistent geotropic nystagmus should wait long enough for the nystagmus to stop (∼2 minutes), test for fatigue by repeating the positional nystagmus tests, incorporate a head flexion component as part of the positional testing, and attempt to identify a null point.Video Abstract available for additional insights from the authors (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A178).
解析持续性、方向变化的向地性眼球震颤的病因可能较为困难。偏头痛和轻嵴帽可能是两种病因，但可能与影响水平半规管的良性阵发性位置性眩晕（BPPV）相混淆。在偏头痛中，持续性向地性眼球震颤往往较慢；在轻嵴帽中，已说明眼球震颤呈与俯位相反的方向跳动。
这里我们描述了一例患者最初出现高速度（≥30 度/秒）、持续性、方向变化的向地性眼球震颤和眩晕，其强度随头部位置变化而变化，难以控制。该患者无偏头痛。该病例表现独特，不太可能是水平半规管的耳石症，但也不明显与轻嵴帽现象有关。
在这种情况下，理疗师试图使用烧烤卷耳石复位手法（CRM），尽管向地性眼球震颤持续存在。在就诊期间，眼球震颤没有得到缓解。
持续的高速度向地性眼球震颤在 1 周内得到缓解，但这种缓解可能是自发的，而不是由于 CRM 干预。我们的病例表明，评估持续性向地性眼球震颤的理疗师应等待足够长的时间，让眼球震颤停止（约 2 分钟），通过重复位置性眼球震颤测试来测试疲劳，将头部弯曲部分纳入位置测试中，并尝试确定零位。视频摘要可提供作者的更多见解（见视频，补充数字内容 1，http://links.lww.com/JNPT/A178）。
