Vestibular perceptual testing from lab to clinic: a review

Abstract

Not all dizziness presents as vertigo, suggesting other perceptual symptoms for individuals with vestibular disease. These non-specific perceptual complaints of dizziness have led to a recent resurgence in literature examining vestibular perceptual testing with the aim to enhance clinical diagnostics and therapeutics. Recent evidence supports incorporating rehabilitation methods to retrain vestibular perception. This review describes the current field of vestibular perceptual testing from scientific laboratory techniques that may not be clinic friendly to some low-tech options that may be more clinic friendly. Limitations are highlighted suggesting directions for additional research.

Keywords: cognition; navigation; perception; spatial orientation; vestibular.

Figure 1

(A) Exemplar image of a subject sitting in a chair mounted to a hexapod base participating in an experiment to quantify roll-tilt threshold. Typically, this experiment would be conducted in the dark to emphasize vestibular signals of inertial motion. Subjects respond with a button press to indicate whether they tilted to the right or the left. (B) In this example the subject is tilted 5° to the right. The solid red line indicates earth vertical and the dashed purple line indicates body orientation after a head centered roll-tilt to the right.

Figure 2

Examples of subjective visual vertical (SVV) testing. (A) Low-tech “bucket” method testing a seated subject (73). (B) Example styles of high-tech SVV testing with projection screens or using virtual reality, (1) tilted line on blank background; (2) “Rod and Frame” - tilted line presented in tilted square; (3) dynamic SVV – background of dots rotating clockwise or counter-clockwise with a tilted line in the center. (C) SVV performed in virtual reality while seated. (D) SVV performed in virtual reality while standing. Patient task in all scenarios is to indicate when the visible line is oriented with vertical either verbally or by button press. Photos in (C,D) digitally altered to improve visibility of the tilted red line presented on the computer monitor.

Figure 3

The triangle completion test (TCT): the TCT (74) is conducted using right triangles, the sides of which are distinctly marked on the floor. Participants don a blindfold and noise-attenuating headphones and, then, are instructed to visualize the triangle to be walked. Participants are passively guided along one leg, a 90° turn, and then the second leg. Once the examiner lets go, participants are instructed to “turn and complete the triangle”.

Figure 4

The gait disorientation test (GDT): during the GDT, the participant is timed while walking 6.1 M with their eyes open and again with their eyes closed. The GDT result is the difference in time needed to walk that distance with eyes closed versus with eyes open. GDT scores ≥4.5 s differentiate vestibular-impaired form healthy adults. Figure adapted from Grove et al. (185).