which must have a rotational component Torsional nystagmus—a diagnostic symptom where the top of the eye rotates toward the affected ear in a beating or twitching fashion, which has a latency and can be fatigued (vertigo should lessen with deliberate repetition of the provoking maneuver): nystagmus should only last for 30 seconds to one minute Pre-syncope—(feeling faint) or syncope (fainting) is unusual, but possible Visual disturbance—due to associated nystagmus, making it difficult to read or see during an attack Nausea—is often associated Vomiting—is common, depending on the strength of vertigo itself and the causes for this illness Many people will report a history of vertigo as a result of fast head movements. Many are also capable of describing the exact head movements that provoke their vertigo. Purely horizontal nystagmus and symptoms of vertigo lasting more than one minute can also indicate BPPV occurring in the horizontal semicircular canal. The spinning sensation experienced from BPPV is usually triggered by movement of the head, will have a sudden onset, and can last anywhere from a few seconds to several minutes. The most common movements people report triggering a spinning sensation are tilting their heads upward in order to look at something and when rolling over in bed. People with BPPV do not experience other neurological deficits such as numbness or weakness. If those symptoms are present, a more serious etiology, such as posterior circulation stroke or ischemia, must be considered. The most significant symptom is nystagmus as it is essential to determine the kind of nystagmus ( horizontal, vertical, or diagonal ) to select the correct cure maneuver. Cause Within the labyrinth of the inner ear lie collections of calcium crystals known as otoconia or otoliths. In people with BPPV, the otoconia are dislodged from their usual position within the utricle, and over time, migrate into one of the three semicircular canals (the posterior canal is most commonly affected due to its anatomical position). When the head is reoriented relative to gravity, the gravity-dependent movement of the heavier otoconial debris (colloquially "ear rocks") within the affected semicircular canal causes abnormal (pathological) endolymph fluid displacement and a resultant sensation of vertigo. This more common condition is known as canalithiasis. There is a direct link between the kind of nystagmus and which of the three semicircular canals is affected. With horizontal nystagmus ( left-right eye movement ) the horizontal ( also called lateral )