Otoliths, also known as benign paroxysmal positional vertigo, are brief paroxysmal episodes of vertigo and nystagmus that occur when the head moves rapidly to a particular head position. Normally the otoliths are attached to the otolithic membrane, but when some pathogenic factors cause the otoliths to detach, these detached otoliths will swim in the fluid called endolymph in the inner ear. The duration of vertigo is usually short, from a few seconds to a few minutes, and can be aggravated or relieved periodically. The duration of the disease varies. The onset of vertigo is sudden and often associated with a change in head position or body position. The symptoms of vertigo appear when the head position (affected ear downward) is excited, and the nystagmus occurs within 3-10 seconds after the head position change. The vertigo can be aggravated or relieved periodically, and there may be no discomfort or dizziness in the interval, and individual patients may have a long period of head heaviness and floating sensation after the vertigo attack. Otolithiasis examination items: 1.Dix-Hallpike dislocation test is the examination and diagnosis method of anterior and posterior hemianopsia. 2.rolltest can be used to diagnose otoliths in the lateral semicircular canal.