Vannucchi Paolo, Pecci Rudi, Giannoni Beatrice
Service of Audiology, Department of Oto-Neuro-Ophthalmology, Surgical Sciences, University of Florence, Viale Morgagni 85, 50100 Florence, Italy.
Int J Otolaryngol. 2012;2012:413603. doi: 10.1155/2012/413603. Epub 2012 Aug 28.
The aim of this study is to verify the hypothesis that free-floating particles could sometimes localize into the distal portion of the non ampullary arm of the posterior semicircular canal (PSC) so that assuming the Dix-Hallpike's positions, the clot could move towards the ampulla eliciting a inhibitory torsional-down beating paroxysmal positional nystagmus (PPNy), instead of typical excitatory torsional-up beating PPNy. Among 45 patients with vestibular signs suggesting anterior semicircular canal paroxysmal positional vertigo (PPV), collected from February 2003 to August 2006, we detected a group of 6 subjects whose clinical findings showed a singular behaviour during follow-up. At the first check-up, all patients were submitted to different types of physical manoeuvres for ASC canalolithiasis. Patients were controlled during the same session and after one week. When we found that nystagmus was qualitatively changed we adopted the appropriate physical therapies for that sign. At a next check-up, after having performed some physical therapies, all patients had a typical PSC PPNy of the opposite side, with respect to that of the ASC initially diagnosed. Basing on these observations we conclude that PSC PPV, similarly to lateral semicircular canal PPV, could manifests in a apogeotropic variant.
游离颗粒有时可能会定位于后半规管（PSC）非壶腹臂的远端，因此在采取 Dix-Hallpike 体位时，血凝块可能会朝着壶腹移动，引发抑制性扭转向下跳动的阵发性位置性眼震（PPNy），而非典型的兴奋性扭转向上跳动的 PPNy。在 2003 年 2 月至 2006 年 8 月收集的 45 例有提示前半规管阵发性位置性眩晕（PPV）前庭体征的患者中，我们发现一组 6 名受试者，其临床表现在随访期间呈现出独特的行为。在首次检查时，所有患者均接受了针对前半规管耳石症的不同类型的物理手法治疗。在同一次治疗期间及一周后对患者进行了检查。当我们发现眼震在性质上发生改变时，我们针对该体征采用了适当的物理治疗方法。在下次检查时，在进行了一些物理治疗后，所有患者相对于最初诊断的前半规管，均出现了对侧典型的后半规管 PPNy。基于这些观察结果，我们得出结论，后半规管 PPV 与外侧半规管 PPV 类似，可能会表现为背地性变体。
