Abstract
Damped off-vertical-axis rotation (OVAR) induces more severe vertigeous sensation compared with earth vertical axis rotation (EVAR) using the damped rotation test because three semicircular canals and otolith organs are stimulated at once. We recorded the ENG of 16 patients, whose ice-water irrigation caloric tests did not show any response in either ear, using the damped rotation test at 0 degrees and at 15 degrees tilt for off vertical axis. The etiology of the patients included inner ear anomaly, meningitis, and acoustic tumors. Our study revealed that nine patients showed perotatory and postrotatory nystagmus upon EVAR and OVAR two patients showed nystagmus up on OVAR only but no nystagmus upon EVAR. Seven patients did not show any nystagmus upon EVAR or OVAR. The modulation component, which relates to the otolith organs, was recorded in six patients. The damped off-vertical-axis rotation test is promising for further evaluation of the semicircular canal and otolithic organs.
