It is because the otolith particles are dislodged in the semicircular canal and turn with the movement of the head position. Since its specific gravity is greater than that of the lymphatic fluid, it will still move due to inertia after the lymphatic fluid stops moving, so a new vestibular stimulation leads to a sensation of movement and nystagmus a few seconds after the head turning stops, but the otolith is not large, so it lasts less than 30 seconds before it stops moving and no longer stimulates the vestibule, so the symptoms last only a few seconds. When the head position was returned, similar symptoms reappeared. When the position is repeatedly changed several times, the symptoms become less and less severe because the piston effect of the otolith disappears, which is the fatigue effect. Of course, there is also the rare case where the otolith is adhered to the potbelly sphenoid and, due to inertia, it moves for a while after the potbelly sphenoid stops moving, producing symptoms for a few seconds. Before treatment, due to repeated stimulation, central sensitization (similar to the mechanism of chronic neuropathic pain) may occur, and it is possible that one side of the vestibule may be sensitive to motor stimulation, or there may be a tension response, and the patient is particularly sensitive to changes in head position. Therefore, most patients will have sensitivity to movement even in the absence of vertigo attacks, and will experience dizziness or unsteadiness during walking and movement. This is not uncommon in clinical practice. After performing epley repositioning, the otolith is fixed and no longer stimulates the nerve, but the patient’s sensitization and tension will not disappear for a short time, so he or she will still have dizziness. We also found that many patients, who were not diagnosed in time, followed VBI treatment ineffectively for a long time and ended up getting better on their own (usually taking 2-4 weeks), not only had heavy residual symptoms (more prone to sensitization or tension), but also might induce anxiety disorders. The patient complained of dizziness and vertigo related to postural changes, then 1 month later the vertigo was absent, but always afraid to sit up or lie down at normal speed, dizziness or faintness every day, and also a brief momentary feeling of unsteadiness or desire to fall, the patient was afraid to walk independently outdoors, reaching the level of anxiety disorder.