vHIT: What are the terms RALP, LARP and laterals in reference to?

The video Head Impulse Test (vHIT) produces a rotational stimulus to the head and then assesses the resulting eye movement via the Vestibulo-Ocular Reflex (VOR). The rotation stimulus is applied in the anatomical planes of the respective semi-circular canals hence each stimulus is best detected by one pair of canals; each canal is a coplanar pair with another canal in the other ear.

“Lateral” refers to a head rotation in the horizontal plane, usually with the head bowed forward by approximately 30°. This best stimulates the horizontal canals of each ear (which are a co-planar pair).

“RALP” means Right Anterior, Left Posterior and refers to a head rotation in an orientation which best stimulates this co-planar pair. “LARP” means Left Anterior, Right Posterior and refers to a head rotation in an orientation which best stimulates this co-planar pair. The below figure is a schematic showing a top-down view of the head, which visualises the orientation of the semi-circular canals of each ear.

An image looking down into the anterior canal, lateral canal and posterior canal on each side.

August 2017
Want to know more about our products or arrange a demonstration? Contact an Interacoustics sales office, call +45-6371-3555, or find a distributor.
Features and/or functions may not be available for all countries or all areas and product specifications are subject to change without prior notification.
Copyright © 2020 Interacoustics A/S. All rights reserved. Privacy policy