[Technique for the assessment of vestibular compensation--clinical observation/quantitative neuro-otometry?]

Reliable evaluation of vestibular compensation in indispensable to determine whether labyrinth surgery or vestibular neurectomy is indicated. It is also important for postoperative follow-up. Vestibular compensation can manifest itself differently in distinct frequency ranges.

Twenty volunteers were examined in five distinct situations of daily vestibular stimulation. Measurement of angular and linear head acceleration was performed using accelerometers fixed on the volunteers' head. A 200 Hz AD fed data to a PC database. FFT was used for data analysis.

Stimulus frequency of the vestibular system varies between 0.01 and 2 Hz. Most of the patients suffering from vestibular lesions showed a reduced vestibulo ocular reflex (VOR) below 0.1 Hz. In all cases of unilateral vestibular function loss, there was a correlation between the symptoms during movement and the corresponding frequency range of the distinct motion pattern. Rotatory vestibular pendular testing was used to document vestibular disorders in patients who had normal findings in routine vestibular testing.

Clinical use of rotatory vestibular pendular testing results must be performed using broad stimulus frequency spectra (0.01-0.06 Hz). This method must be used in preoperative examination before labyrinth surgery as well as in estimating individual tolerance for vestibular stimulation in daily situations.