J Korean Bal Soc.  2004 Dec;3(2):351-355.

Comparison of Vestibule-ocular Reflex of Eccentric Rotation with Centric Rotation in Normal Subjects

• Cho BH
• Jang SY
• Choi HS
• Lee SC
• Kim KS

Abstract

BACKGROUND AND OBJECTIVES:Conventional vestibular rotation testing with the head centered on the axis stimulates the semicircular canals evoking compensatory eye movements. By placing subjects off from the axis of rotation, the otolithic organ may also be simultaneously stimulated by additional linear acceleration forces. In the present study, we compared the rotation with subjects placed on axis to those placed in an eccentric position. MATERIALS AND METHOD:In the eccentric rotation, the head of subject was facing outward and placed eccentrically for 33cm on naso-occipital axis. Slow harmonic acceleration test and velocity step test were performed.
RESULTS
The sinusoidal eccentric rotation at 0.32, 0.64 Hz produced a significantly higher vestibulo-ocular reflex gain than did on axis rotation. In velocity step test, initial slow component velocity was significantly higher in eccentric rotation than in centric rotation.
CONCLUSION
These finding suggest that the gain enhancement due to eccentric rotation is a result of tangentiallinear acceleration, probably sensed by the otolithic organ. This study raises the possibility of using eccentric rotation for the diagnosis of the patients with otolithic dysfunction.

Keyword

Vestibule-ocular reflex; Otolith; Rotation

MeSH Terms

Acceleration
Axis, Cervical Vertebra
Diagnosis
Exercise Test
Eye Movements
Head
Humans
Otolithic Membrane
Reflex*
Reflex, Vestibulo-Ocular
Semicircular Canals