We report the results of questionnaires about daily balance functions in 57 patients with unilateral vestibular loss after surgery for acoustic neurinoma. In many cases, imbalance increased temporarily after operation, but soon returned to almost the preoperative state. Head or body imbalance was most often experienced during sudden head movements as looking back or bending down to pick things up. However, we found no significant correlation between the results of gaze function tests (passive rotation test, high frequency head oscillation test) and the results of questionnaires. We selected the following five factors as fundamental elements related to difficulty of daily actions, 1) modality of movement (active or passive), 2) presence of head movement, 3) vision, 4) transfer of the center of gravity, 5) supporting area of the sole.
Theoretically, it is possible to evaluate daily balance functions by examining several representative movements the difficulties of which are decided mostly by one of these factors.