鑑別診斷中樞性眩暈和周邊性眩暈之HINTS法則

HINTS Protocol for Differential Diagnosis between Central and Peripheral Vertigo

鑑別診斷中樞型和周圍型眩暈是急診室的重大挑戰，因為中樞型眩暈中，僅有約50%的息者會伴隨局部神經學症狀，而電腦斷層掃描對急性腦幹或小腦中風的敏感度低於50%。其他重要的鑑別診斷方法，包括中風危險因子的評估，站立和步態的評估，以及快速的床邊眼球運動評估–HINTS。HINTS，是三個床邊檢查（head impulse test, nystagmus, and test of skew deviation）的合稱，目前被認為是鑑別中樞型和周圍型眩暈最實用的方法。急性眩暈並伴隨眼振出現時，根據HINTS法則，若頭脈衝試驗正常，或眼振方向呈現中樞性眼振特徵，或是有垂直眼位偏斜，三者有其一，皆代表可能為中樞型眩暈，需要進一步檢查。此文針對各種鑑別中樞型和周圍型眩暈的方法，作一深入的探討，並介紹HINTS的學理、操作方法、和正確使用時機。

Differential diagnosis of central and peripheral vertigo is a challenge in the emergency room, because only about 50% of patients with central vertigo are associated with focal neurological signs, and CT scan has low sensitivity for acute brainstem or cerebellar stroke (<50%). Other important diagnostic methods include assessment of stroke risk factors, assessment of stance and gait, and rapid bedside oculomotor assessment – HINTS. HINTS, a combination of three bedside tests (Head Impulse test, Nystagmus, and Test of Skew deviation), is currently considered the most practical method to differentiate central and peripheral vertigo. In acute vertigo with nystagmus, normal head impulse test, central-type nystagmus, or skew deviation suggests a central vertigo and requires further investigation. This article makes an in-depth discussion on various methods of distinguishing central and peripheral vertigo, and introduces the theory, the operation method, and the time of application for HINTS.