Somatosensory cuing of head-only rotational testing

Abstract

Head-only rotational testing (HORT) is a method of assessing the vestibulo-ocular reflex (VOR) that can be performed at the bedside with inexpensive, transportable equipment. Previous studies of HORT using auditory cuing have suggested that test results are in large part independent of the method by which a subject's head is moved, that is, active versus passive. However, many subjects have difficulty moving their head at rotational frequencies of 3 Hz or greater. In an attempt to overcome this difficulty, and to learn more about HORT, we explored the possibility of providing subjects with a somatosensory, rather than an auditory cue for head movement. Somatosensory, cues were provided either by applying gentle pressure against a tightly-fitted headband or by lightly tapping on the shoulders. Our results with young, healthy subjects indicate that somatosensory cuing is an efficacious means of inducing periodic head rotation and that HORT results are unaffected by the type of cue provided. We conclude that somatosensory rather than auditory cuing may be the preferred method of performing HORT.