Vestibular compensation after acute unilateral vestibular loss plays an important role in reducing uncomfortable symptoms, such as strong rotatory vertigo, nausea, and vomiting. In most cases of acute unilateral vestibular loss, the vestibular functions of the healthy side are temporally reduced but subsequently recover. This phenomenon is well known as vestibular compensation. In addition, the vestibular functions of the affected side also recover in some cases. To obtain an overall understanding of the vestibular function in cases with acute unilateral vestibular loss, vestibular function must be tested several times. However, the caloric test is not suitable for repetitive evaluations of vestibular function because it is time-consuming, labor-intensive, and tends to cause nausea.
The video Head Impulse Test (vHIT), a novel semicircular canal function test that was developed in 2009, is suitable for repetitive evaluations of vestibular function. The vHIT can be performed relatively quickly and is unlikely to cause nausea.
Here, we report a case of Ramsey-Hunt syndrome with frequent changes in the direction of gazed-nystagmus. We were able to evaluate the patient's complicated clinical course of vestibular function using vHIT in detail. We concluded that vHIT is a useful test for evaluating the clinical course of bilateral vestibular function in cases of acute unilateral vestibular loss.
