Gaze stabilization and gait performance in vestibular dysfunction

Background: The gaze stability test (GST) quantifies the ability of a person to recognize a target projected on a personal Computer monitor during active head movement. Purpose: The purpose of this study was to determine if there was a relationship between clinical measures of walking performance and the GST in patients with vestibular disorders and in healthy subjects. We hypothesized that impairment of the ability to keep objects in focus during active head movement would be correlated with walking performance. Subjects: Twenty older asymptomatic adults acted as controls and 12 patients with either unilateral or bilateral vestibular disease participated. Methods: The GST quantifies the maximum velocity that a person can move their head in the pitch and yaw planes while retaining the ability to read an optotype that is momentarily projected onto a computer screen. Subjects were scored while performing the Dynamic Gait Index (DGI) and the Timed Up & Go (TUG) tests. Results: Walking performance on the DGI and TUG were significantly associated with GST results in subjects with vestibular disorders, but not in control subjects. Abnormalities of gait could be identified by GST cutoff values of 65 degrees s(-1) in the pitch plane and 63 degrees s(-1) in the yaw plane. Discussion/conclusion: In older subjects with vestibular disorders, gaze stability, as assessed by the GST, is associated with reduced test scores on measures of gait performance. (c) 2008 Published by Elsevier B.V.