Documentation of the Recovery Course and Deficit Side Localization of an Acute Unilateral Vestibular Deficit Using Four-quadrant Diagrams of Slow Phase Velocity

Abstract

The horizontal vestibulo-ocular reflex was studied in normals and in patients with an acute or compensated unilateral peripheral vestibular deficit (PVD) in order to determine the efficacy of various response measures of deficit side and central compensation for high rotation velocities. The profiles of whole body rotation and the visual fixation period was chosen to yield slow phase velocity (SPV) profiles comparable with those obtained with caloric irrigation. The chair rotation direction producing the smaller amplitude of slow phase velocity measured over culmination period obtained with 40 s of 5°/s² constant acceleration to 200°/s represented a lateralizing sign of all acute, and 85% of all compensated PVD cases.

Key Words:

• vestibular ocular reflex
• unilateral vestibular deficit
• rotating chair
• caloric test