Long-latency rotational evoked potentials in subjects with and without bilateral vestibular loss.

Human subjects with and without profound bilateral vestibular loss were evaluated using repetitive rotational stimulation about an earth-vertical axis and signal averaging of vertex-recorded potentials. The stimulus events to which averaging was synchronized were acceleration/deceleration pulses produced by abrupt reversals in direction of angular velocity. In control subjects the long-latency rotational evoked potentials elicited via this paradigm were robust and reproducible. The responses of subjects with vestibular loss did not differ remarkably from those of the control subjects. We conclude that the long-latency rotational evoked potential elicited using a conventional rotary chair is not primarily of vestibular origin.