Department of Otorhinolaryngology, Myongji Hospital, Goyang, South Korea.
JAMA Otolaryngol Head Neck Surg. 2014 Mar;140(3):250-2. doi: 10.1001/jamaoto.2013.6207.
Nystagmus can occur spontaneously from multiple causes. Direction-changing positional nystagmus on the supine roll test is a characteristic clinical feature in horizontal semicircular canal benign paroxysmal positional vertigo. One of several mechanisms of spontaneous nystagmus is plugging of the otoconia, which has been described as a canalith jam.
We evaluated a 52-year-old woman with a history of geotropic variant of horizontal semicircular canal benign paroxysmal positional vertigo on the right side who had been treated with a modified Lempert maneuver 3 months earlier. The patient had persistent spontaneous nystagmus, despite a positional change after the canalith repositioning procedure. A bithermal caloric test result demonstrated unilateral canal paresis on the right side. The following day, the patient's symptoms and nystagmus had subsided. On a repeated bithermal caloric test, a normal response was demonstrated on both sides.
To our knowledge, this is the first report of a case that shows on video persistent nystagmus findings consistent with a canalith jam. We discuss a possible mechanism underlying this phenomenon.
眼球震颤可能由多种原因自发产生。在仰卧位滚转试验中，位置性变向眼球震颤是水平半规管良性阵发性位置性眩晕的一个特征性临床特征。自发眼球震颤的几种机制之一是耳石栓塞，这被描述为耳石嵌塞。
我们评估了一位 52 岁女性，右侧有地感性水平半规管良性阵发性位置性眩晕病史，3 个月前接受了改良 Lempert 手法治疗。尽管在耳石复位术后位置发生了变化，但患者仍持续出现自发性眼球震颤。双侧冷热温度试验结果显示右侧单侧半规管功能减退。次日，患者的症状和眼球震颤缓解。重复进行双侧冷热温度试验，两侧均显示正常反应。
据我们所知，这是首例报告显示与耳石嵌塞一致的持续性眼球震颤表现的病例。我们讨论了这种现象的可能机制。
