Does utricular stimulation elicit nystagmus in humans?

BACKGROUND

Stimulation of the utricle has been hypothesized to elicit nystagmus. However, the observation that nystagmus rarely occurs immediately following the Epley maneuver for posterior semicircular canal benign paroxysmal positional vertigo has raised questions about the existence of a robust otolith-ocular reflex.

OBJECTIVE

To determine whether nystagmus can be elicited from the utricle by applying linear acceleration.

MATERIALS AND

METHODS

The subjects were 10 healthy individuals. Each subject was seated in a wheelchair, rotated their upper body 90° to the right, and moved side to side. The amplitude was approximately 0.2 m, with a frequency of 0.33 Hz.

RESULTS

In all subjects, no eye drift was observed in response to body movement.

CONCLUSIONS AND SIGNIFICANCE: Low-frequency stimulation of the utricle does not always produce nystagmus. Therefore, we need to reconsider the function of the utricle.