Objective: To evaluate the influence of asymmetry of vestibular caloric response and age on balance and perceived symptoms after acute unilateral vestibular loss.
Design: Prospective study.
Setting: Ear, nose and throat departments in three hospitals.
Subjects: Fifty-four patients (mean age 52 years) with acute unilateral vestibular loss participating in a randomized controlled training study were included.
Main measures: Electronystagmography testing was performed within one week after onset of symptoms and after 10 weeks. The outcome measures clinical static balance tests (sharpened Romberg's test with eyes closed, standing on foam with eyes closed, and standing on one leg with eyes open and closed) and subjective symptom ratings on a visual analogue scale were done after one week, 10 weeks and six months. The correlation between age and asymmetry of vestibular caloric response, respectively, and the outcome measures were analysed.
Results: Greater caloric asymmetry correlated with poorer performance at the sharpened Romberg's test and standing on one leg with eyes closed at all three follow-ups (rho = -0.31 to -0.54), and with higher symptom ratings at the 10-week and six-month follow-ups (rho = 0.30-0.60). Higher age was associated with poorer performance on the sharpened Romberg's test and standing on one leg at all three follow-ups (rho = 0.31-0.64), but did not change over time. Higher age was also associated with higher ratings of vertigo at the six-month follow-up, and less reduction of vertigo between the 10-week and six-month follow-ups (rho = 0.29-0.48).
Conclusions: A higher degree of asymmetry of vestibular caloric response and high age seem to be associated with poor outcome in balance and perceived symptoms after acute unilateral vestibular loss.