Porwal Prateek, V R Ananthu, Pawar Vishal, Dorasala Srinivas, Bijlani Avinash, Nair Prem, Nayar Ravi
Vertigo and Balance Clinic, Bangalore, India.
Aster Clinic, Zen Cluster, Discovery Gardens, Dubai, United Arab Emirates.
Front Neurol. 2021 Mar 10;12:618269. doi: 10.3389/fneur.2021.618269. eCollection 2021.
To define diagnostic VNG features in anterior canal BPPV during positional testing (Dix-Hallpike, supine head hanging, and McClure Pagnini tests). A retrospective study of patients diagnosed with anterior canal BPPV across four referral centers in New Delhi, Kochi, Bangalore, and Dubai. Clinical records of 13 patients with AC BPPV out of 1,350 cases, during a 3-years period, were reviewed and analyzed by four specialists. Four patients had positional down beating nystagmus with symptoms of vertigo during the bilateral DHP maneuver. Seven cases had positional down beating nystagmus only on one side of DHP. Typical down beating nystagmus was seen in 10 out of 13 cases during the straight head hanging maneuver. Down beating torsional nystagmus was seen in 6 out of 13 cases. Down beating with horizontal nystagmus was seen in three cases (in DHP and MCP mainly) while pure down beating nystagmus during SHH was only seen in four cases. We conclude that anterior canal BPPV is a rare but definite entity. It may not be apparent on positional testing the first time, so repeated testing may be needed. The most consistent diagnostic maneuver is SHH though there were patients in which findings could only be elicited using DHP testing. We recommend a testing protocol that includes DHP testing on both sides and SHH. MCP testing may also evoke DBN with or without the torsional component. Reversal of nystagmus on reversal of testing position is unusual but can occur. The Yacovino maneuver is effective in resolving AC BPPV. We also propose a hypothesis that explains why DHP testing is sensitive to AC BPPV on either side, whereas MCP lateral position on one side is only sensitive to AC BPPV on one side. We have explained a possible role for the McClure Pagnini test in side determination and therapeutic implications.
确定在前庭半规管良性阵发性位置性眩晕（BPPV）进行位置试验（Dix-Hallpike试验、仰卧垂头试验和McClure Pagnini试验）时的诊断性视频眼震图（VNG）特征。对新德里、科钦、班加罗尔和迪拜四个转诊中心诊断为前半规管BPPV的患者进行回顾性研究。在3年期间，对1350例病例中的13例前半规管BPPV患者的临床记录进行了回顾，并由四位专家进行分析。4例患者在双侧Dix-Hallpike试验（DHP）中出现位置性下跳性眼震并伴有眩晕症状。7例患者仅在一侧DHP试验中出现位置性下跳性眼震。13例患者中有10例在直头悬挂试验中出现典型的下跳性眼震。13例患者中有6例出现下跳性扭转性眼震。3例患者出现下跳性伴水平性眼震（主要在DHP试验和McClure Pagnini试验（MCP）中），而在仰卧垂头试验（SHH）中仅4例出现单纯下跳性眼震。我们得出结论，前半规管BPPV是一种罕见但明确的疾病。首次位置试验时可能不明显，因此可能需要重复试验。最一致的诊断手法是SHH试验，尽管有些患者的表现仅通过DHP试验才能引出。我们建议一种测试方案，包括双侧DHP试验和SHH试验。MCP试验也可能诱发伴有或不伴有扭转成分的下跳性眼震。测试位置反转时眼震反转不常见，但可能发生。Yacovino手法对解决前半规管BPPV有效。我们还提出了一个假设，解释了为什么DHP试验对两侧的前半规管BPPV敏感，而一侧的MCP侧卧位仅对一侧的前半规管BPPV敏感。我们解释了McClure Pagnini试验在确定患侧和治疗方面可能的作用。
