水平半规管BPPV中可逆的摇头后眼震作为前庭功能减退的机械性模拟：一例病例报告。

文献信息

中文摘要

目的： 描述与水平半规管良性阵发性位置性眩晕（BPPV）相关的短暂摇头后眼震及其在耳石复位后的缓解。
方法： 一名78岁女性因位置性眩晕就诊。视频眼震图显示左向自发性眼震样眼震及明显的左向pHSN，最初提示失代偿性单侧前庭病。进一步的床旁评估，包括头俯仰试验和仰卧滚转试验，显示方向变化的水平眼震，符合左侧水平半规管耳石症。
结果： 在一次不成功的Lempert手法后，施行了Gufoni手法，眩晕和眼震立即缓解。在10天随访时，未观察到自发性、位置性或摇头后眼震。患者在14个月随访期间一直无症状，复查时水平vHIT反应保留。
结论： 本病例提示，水平半规管BPPV中的摇头后眼震可能源于短暂的机械触发的不对称，而非固定的前庭缺陷。仅依赖pHSN可能导致误诊和不恰当的诊断解读。结合位置试验和耳石复位后的再评估，可能有助于避免将摇头后眼震误判为单侧前庭功能减退。

英文摘要

PURPOSE: To describe transient post-head-shaking nystagmus associated with horizontal canal benign paroxysmal positional vertigo (BPPV) and its resolution following canalith repositioning.
METHODS: A 78-year-old woman presented with positional vertigo. Video-oculography revealed left-beating pseudo-spontaneous nystagmus and a robust left-beating pHSN, initially suggestive of uncompensated unilateral vestibulopathy. Further bedside assessment, including the Head Pitch test and Supine Roll test, demonstrated direction-changing horizontal nystagmus consistent with left horizontal canalolithiasis.
RESULTS: After an unsuccessful Lempert maneuver, a Gufoni maneuver was performed, resulting in immediate resolution of vertigo and nystagmus. At 10-day follow-up, no spontaneous, positional, or post-head-shaking nystagmus was observed. The patient remained asymptomatic throughout 14-month follow-up, with preserved horizontal vHIT responses at reassessment.
CONCLUSION: This case suggests that post-head-shaking nystagmus in horizontal canal BPPV may arise from transient mechanically triggered asymmetry rather than a fixed vestibular deficit. Reliance on pHSN alone may lead to misdiagnosis and inappropriate diagnostic interpretation. Incorporating positional testing and reassessment following canalith repositioning may help avoid misinterpretation of post-head-shaking nystagmus as unilateral vestibular hypofunction.