Testing of the Vestibular System by Sinusoidal Angular Acceleration

Sinusoidal stimulation of the horizontal semicircular canals was evaluated in 22 normal and 53 abnormal individuals. Nystagmic responses were analysed for both linearity and preponderance as a function of the period and specific frequency of stimulation. Many of the abnormal vestibular cases demonstrated a directional preponderance which, at low-frequency stimulation, was particularly suggestive of severe pathology. This examination enhanced the caloric evaluation, demonstrated possible mechanisms of compensation and provided a method of following changing pathologic conditions.