Low and high frequency sinusoidal rotational testing in patients with peripheral vestibular lesions

We found a consistent pattern of response to low and high frequency sinusoidal rotational testing in patients with chronic compensated unilateral and bilateral peripheral vestibular lesions. Gain (peak slow phase eye velocity/peak chair velocity) was decreased and phase lead increased at low frequencies but both measurements approached normal at high frequencies. Asymmetries in gain, when present, were approximately the same in the low and high frequency range. These changes can be explained by a simple first order linear model of the vestibulo-ocular reflex if one assumes that the goal of the compensation process is to maintain gain in the high frequency range.