Persistent static imbalance among acute unilateral vestibulopathy patients could be related to a damaged velocity storage system.

Background: Acute unilateral vestibulopathy (AUV) is common but, the course of disease recovery is variable. Moreover, the final recovery status might vary between subjects. The remaining symptoms of these patients indicate the poor recovery of static imbalance, which could limit social activities and decrease their quality of life. Objective: To determine the possible predictive parameters of prolonged static imbalance (PSI) among acute AUV, we compared several vestibular function test (VFT) results between control vestibulopathy (CV) and PSI patients. Materials and methods: Subjects were divided into two groups: PSI and CV. PSI was determined by the observation of spontaneous nystagmus at 1 month after discharge from the hospital. VFT results taken during the initial symptoms were compared. Results: Increased phase lead was observed in low-frequency stimulations (p < .05), while the other test results failed to reveal a significant difference. These results indicate that a larger phase lead, which is related to a decrease in the time constant, could be responsible for the delayed recovery of static imbalance. Conclusion and significance: The phase lead was higher in the PSI group compared to the CV group, suggesting the possible role of phase as a parameter to predict the delayed compensation of static imbalance.