Califano L, Melillo M G, Mazzone S, Vassallo A
Unit of Audiology and Phoniatrics, ENT Clinic, "G. Rummo" Hospital, Benevento, Italy.
Acta Otorhinolaryngol Ital. 2008 Dec;28(6):287-91.
Liberatory treatment of lateral canalolithiasis is more effective for the geotropic, than for the apogeotropic forms and, therefore, it is worthwhile attempting to convert the apogeotropic forms into the geotropic forms. In 36 cases of apogeotropic lateral canalolithiasis, one to five Head-Pitch Manoeuvres were performed in the sitting position (Head-Pitch Test) in the attempt to transform apogeotropic into geotropic lateral canalolithiasis. The Head Pitch Test was performed by a quick 60 degrees forward-flexion and a slow maximal backward-extension of the head. The Head-Pitch Test was effective in 36.1% of cases, less than the repeated Head-Rolling in the supine position, but it was always well tolerated by patients. The quick 60 degrees forward-flexion of the head can evoke a horizontal nystagmus beating towards the healthy side in apogeotropic lateral canalolithiasis and towards the affected side in geotropic lateral canalolithiasis (Bow Nystagmus). Slow backward-extension of the head can evoke a horizontal nystagmus beating towards the affected side in apogeotropic lateral canalolithiasis and toward the healthy side in geotropic lateral canalolithiasis (Lean Nystagmus). Conversion from apogeotropic to geotropic lateral canalolithiasis by the Head-Pitch Test was effective when Bow and Lean Nystagmus changed directions or when the Head-Pitch Test evoked Bow Nystagmus toward the affected side and Lean Nystagmus toward the healthy side. Conversion occurred in 10 patients during the 60 degrees forward-flexion of the head. In contrast, in 3 patients, it occurred during extension of the head, when a "Lean Nystagmus" toward the healthy side appeared. In addition, Pseudospontaneous Nystagmus and Positioning Nystagmus that arose when the patient moved from the sitting to the supine position changed direction or were evoked ex-novo, both directed toward the healthy side. In all cases, Pagnini-McClure diagnostic manoeuvre confirmed the transformation with a Positional Paroxysmal Horizontal Geotropic Nystagmus, which was more intense when the affected ear was brought down. The Head-Pitch Test can be used as the method of choice to transform apogeotropic into geotropic lateral canalolithiasis. However, anterior flexion of the head in the geotropic forms must be avoided since involuntary and harmful transformations from the geotropic into the apogeotropic form can occur, moving otoliths towards the anterior arm and cupula.
半规管结石症的解脱治疗对向地性类型比对背地性类型更有效，因此，值得尝试将背地性类型转变为向地性类型。在36例背地性半规管结石症患者中，在坐位进行了一至五次头前倾动作（头前倾试验），试图将背地性半规管结石症转变为向地性半规管结石症。头前倾试验通过头部快速向前屈曲60度并缓慢最大程度向后伸展来进行。头前倾试验在36.1%的病例中有效，低于仰卧位重复摇头试验，但患者对此耐受性良好。在背地性半规管结石症中，头部快速向前屈曲60度可诱发向健康侧跳动的水平眼震，而在向地性半规管结石症中则诱发向患侧跳动的水平眼震（弓状眼震）。头部缓慢向后伸展可在背地性半规管结石症中诱发向患侧跳动的水平眼震，而在向地性半规管结石症中则诱发向健康侧跳动的水平眼震（倾斜眼震）。当头前倾试验诱发的弓状眼震和倾斜眼震改变方向，或者头前倾试验诱发向患侧的弓状眼震和向健康侧的倾斜眼震时，通过头前倾试验将背地性半规管结石症转变为向地性半规管结石症是有效的。在10例患者中，在头部向前屈曲60度时发生了转变。相比之下，在3例患者中，转变发生在头部伸展时，此时出现了向健康侧的“倾斜眼震”。此外，当患者从坐位移动到仰卧位时出现的假性自发性眼震和定位性眼震改变了方向或重新诱发，均指向健康侧。在所有病例中，帕尼尼-麦克卢尔诊断动作通过位置性阵发性水平向地性眼震证实了这种转变，当患耳向下时这种眼震更强烈。头前倾试验可作为将背地性半规管结石症转变为向地性半规管结石症的首选方法。然而，在向地性类型中必须避免头部前屈，因为可能会发生从向地性到背地性形式的非自愿且有害的转变，使耳石移向壶腹嵴前部。
