坐位低頭眼振診斷逆地型水平半規管良性陣發性眩暈之病耳－四例報告

Head Pitch down Nystagmus While Sitting Detects Affected Side of Ageotropic Horizontal Canal Benign Paroxysmal Positional Vertigo-A Report of Four Cases

范君揚(Jun-Yang Fan) ； 陳穆寬(Mu-Kuan Chen)

《台灣耳鼻喉頭頸外科雜誌》 46卷2期 (2011/04) Pp. 102-107

https://doi.org/10.6286/2011.46.2.102

摘要

治療逆地型(ageotropic)與向地型(geotropic)水平半規管良性陣發性眩暈(horizontal canal benign paroxysmal positional vertigo H-BPPV)，決定病耳是重要的第一步驟。根據Ewald's 2(上標 nd) law眼振強側爲向地型的病耳，眼振弱側是逆地型的病耳。但逆地型的囊側(utricular side)頂帽(cupula)沈石的眼振可能和對側耳的管側(canal side)頂帽沈石表現一樣，眼振弱側未必是病側。因此治療送地型水平半規管良性陣發性眩暈可能無法一開始說正確診斷病耳，只能根據治療結果修正方法。近年來有些研究想要使用輔助眼振正確診斷病耳，我們嘗試以坐位低頭眼振(head pitch down nystagmus while sitting)來協助病耳診斷，報告使用於臨床4個病例的經驗，每一例的低頭眼振都正確指向健耳，並歸納初始治療原則爲持續姿努法(forced prolonged position, FPP)向低頭眼振方向或快速轉頭法向低頭眼振對側。特別是對於判斷道地眼振強弱有疑義的病患，更有其臨床實用價值。

關鍵字

逆地型 ； 水平半規管良性陣發性眩暈 ； 低頭眼振

並列摘要

The first and vital step in managing horizontal canal benign paroxysmal positional vertigo (H-BPPV) is detection of lesion side both in ageotropic form (aH-BPPV) and geotropic form (gH-BPPV). It is generally agreed that the side with more intense nystagmus is the affected one in gH-BPPV and the side with less intense nystagmus in aH-BPPV in accordance with Ewald's 2nd law. However, the diagnosis of lesion side is less straightforward in aH-BPPV due to the possibility that the nystagmus with otoconia attached to the utricular side of cupula can be indistinguishable from the one with otoconia attached to the canal side of contralateral cupula. It's not uncommon to treat aH-BPPV without knowing the lesion side in the first attempt. The treatment plan is then modified with subsequent results. Some research in recent years tried to make the correct diagnosis of lesion side with auxiliary nystagmus. We reported that ”head pitch down nystagmus while sitting” detected the lesion side of aH-BPPV and presented 4 cases to illustrate the effect. The head pitch down nystagmus beat toward the healthy side in every one of our patients. We propose initial treatment with forced prolonged position (FPP) toward the direction of head pitch down nystagmus or rapid head turning to the opposite direction in aH-BPPV patients especially in those whose information drawn from ageotropic nystagmus is inconclusive.

並列關鍵字

ageotropic ； horizontal canal benign paroxysmal positional vertigo ； head pitch down nystagmus