Horizontal head-shaking test: pathophysiological mechanisms and clinical interpretation.

ABSTRACT: The horizontal head-shaking test (HST) is a simple, rapid, and non-invasive bedside maneuver that provides valuable insights into both peripheral and central vestibular function. Originally described in the late 19th century and standardized in the 1970s, the HST predominantly stimulates the lateral semicircular canals (LSCs) at high frequencies. Its diagnostic power lies in revealing dynamic asymmetries of the angular vestibulo-ocular reflex (aVOR) and uncovering central abnormalities involving the brainstem and, above all, cerebellum. The pathophysiological basis of post-head-shaking nystagmus (post-HSN) derives from Ewald's second law, which explains the excitatory-inhibitory imbalance between the labyrinths, further processed through the velocity storage mechanism (VSM). The VSM extend

SUBMITTER: Marcelli V 

PROVIDER: S-EPMC12819329 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature