We have treated 6 patients with the Tullio phenomenon and the fistula sign at the same time, and were able to make ENG records. The findings of the tympanic membranes were almost normal and serologic testings for syphilis were negative in all cases.
The frequencies of 250Hz, 500Hz and 1kHz were the most effective in producing the Tullio phenomenon.
In one case, nystagmus toward the stimulated ear during the sound stimulus and transiently toward the opposite ear after the stimulus, was observed. Both the ves tibuloocular reflex and the vestibulospinal reflex were recorded in this case.
Our investigations in these 6 cases indicated that either a hydrostatic route, from the footplate via the membranous labyrinth to the cupula, or hyperexcitablity of the vestibular labyrinth contributed to the production of the Tullio phenomenon and the fistula sign.