Chronic Symptoms After Vestibular Neuritis and the High-Velocity Vestibulo-Ocular Reflex

Abstract

Hypothesis: As the anterior and posterior semicircular canals are vital to the regulation of gaze stability, particularly during locomotion or vehicular travel, we tested whether the high-velocity vestibulo-ocular reflex (VOR) of the three ipsilesional semicircular canals elicited by the modified Head Impulse Test would correlate with subjective dizziness or vertigo scores after vestibular neuritis (VN).

Background: Recovery after acute VN varies with around half reporting persistent symptoms long after the acute episode. However, an unanswered question is whether chronic symptoms are associated with impairment of the high-velocity VOR of the anterior or posterior canals.

Methods: Twenty patients who had experienced an acute episode of VN at least 3 months earlier were included in this study. Participants were assessed with the video head impulse test (vHIT) of all six canals, bithermal caloric irrigation, the Dizziness Handicap Inventory (DHI), and the Vertigo Symptoms Scale short-form (VSS).

Results: Of these 20 patients, 12 thought that they had recovered from the initial episode whereas 8 did not and reported elevated DHI and VSS scores. However, we found no correlation between DHI or VSS scores and the ipsilesional single or combined vHIT gain, vHIT gain asymmetry orcaloric paresis. The high-velocity VOR was not different between patients who thought they had recovered and patients who thought they had not.

Conclusion: Our findings suggest that chronic symptoms of dizziness after VN are not associated with the high-velocity VOR of the single or combined ipsilesional horizontal, anterior, or posterior semicircular canals.

Figure 1. vHIT VOR gains for the ipsilesional A). Horizontal, B). Anterior and C). Posterior canals and vHIT gain asymmetry for the A). Horizontal, B). Anterior and C). Posterior canals versus DHI score. vHIT assessment did not correlate with DHI score

Figure 2. vHIT VOR gains for the ipsilesional A). Horizontal, B). Anterior and C). Posterior canals and vHIT gain asymmetry for the A). Horizontal, B). Anterior and C). Posterior canals versus VSS score. vHIT assessment did not correlate with VSS score

Figure 3. vHIT VOR gain for the total response versus DHI score (A) and VSS score (B) & vHIT VOR gain for the vertical canal (anterior + posterior canals) response versus DHI score (C) and VSS score (D)