Sunday, April 19, 2009

Up To Your Ears In Crystals?

Benign Paroxysmal Positional Vertigo

Timothy C. Hain, MD.

Ear Rocks      In Benign Paroxysmal Positional Vertigo (BPPV) dizziness is generally thought to be due to debris which has collected within a part of the inner ear.  This debris can be thought of  as "ear rocks", although the formal name is "otoconia". Ear rocks are small crystals of calcium carbonate derived from a structure in the ear called the "utricle" (figure1 ).

      While the saccule also contains otoconia, they are not able to migrate into the canal system. The utricle may have been damaged by head injury, infection, or other disorder of the inner ear, or may have degenerated because of advanced age. Normally otoconia appear to have a slow turnover.


      They are probably dissolved naturally as well as actively reabsorbed by the "dark cells" of the labyrinth (Lim, 1973, 1984), which are found adjacent to the utricle and the crista, although this idea is not accepted by all (see Zucca, 1998, and Buckingham, 1999).

       BPPV is a common cause of dizziness. About 20% of all dizziness is due to BPPV. While BPPV can occur in children (Uneri and Turkdogan, 2003), the older you are, the more likely it is that your dizziness is due to BPPV. About 50% of all dizziness in older people is due to BPPV. In a recent study, 9% of a group of urban dwelling elders were found to have undiagnosed BPPV (Oghalai et al., 2000).

          The symptoms of BPPV include dizziness or vertigo, lightheadedness, imbalance, and nausea. Activities which bring on symptoms will vary among persons, but symptoms are almost always precipitated by a change of position of the head with respect to gravity. Getting out of bed or rolling over in bed are common "problem" motions . Because people with BPPV often feel dizzy and unsteady when they tip their heads back to look up, sometimes BPPV is called "top shelf vertigo." Women with BPPV may find that the use of shampoo bowls in beauty parlors brings on symptoms. A Yoga posture called the "down dog", or Pilates are sometimes the trigger. An intermittent pattern is common. BPPV may be present for a few weeks, then stop, then come back again.

Supplemental material on the site DVD: Animation of otoconia being displaced into posterior canal


          The most common cause of BPPV in people under age 50 is head injury . There is also a strong association with migraine (Ishiyama et al, 2000). In older people, the most common cause is degeneration of the vestibular system of the inner ear. BPPV becomes much more common with advancing age (Froeling et al, 1991). Viruses affecting the ear such as those causing vestibular neuritis and Meniere's disease are a significanct causes. Minor strokes such as those involving anterior inferior cerebellar artery (AICA) syndrome", autoimmune disorders, are unusual causes. Occasionally BPPV follows surgery, where the cause is felt to be a combination of a prolonged period of supine positioning, or ear trauma when the surgery is to the inner ear (Atacan et al 2001). While rarely encountered, BPPV is also common in persons who have been treated with ototoxic medications such as gentamicin (Black et al, 2004). In half of all cases, BPPV is called "idiopathic," which means it occurs for no known reason. Other causes of positional symptoms are discussed here.


          A physician can make the diagnosis based on your history, findings on physical examination, and the results of vestibular and auditory tests. Often, the diagnosis can be made with history and physical examination alone. The figure to the right illustrates the Dix-Hallpike test. In this test, a person is brought from sitting to a supine position, with the head turned 45 degrees to one side and extended about 20 degrees backward. A positive Dix-Hallpike tests consists of a burst of nystagmus (jumping of the eyes). The eyes jump upward as well as twist so that the top part of the eye jumps toward the down side. Click here to see a movie of BPPV nystagmus. (13 meg download). The test can be made more sensitive by having the patient wear Frenzel goggles or a video goggle. Most doctors that specialize in seeing dizzy patients have these in their office.


     With respect to history, the key observation is that dizziness is triggered by lying down, or on rolling over in bed. Most other conditions that have positional dizziness get worse on standing rather than lying down (e.g. orthostatic hypotension). There are some rare conditions that have symptoms that resemble BPPV. Patients with certain types of central vertigo such as the spinocerebellar ataxias may have "bed spins" and prefer to sleep propped up in bed (Jen et al, 1998). These conditions can generally be detected on a careful neurological examination and also are generally accompanied by a family history of other persons with similar symptoms.

          Electronystagmography (ENG) testing may be needed to look for the characteristic nystagmus (jumping of the eyes) induced by the Dix-Hallpike test. It has been claimed that BPPV accompanied by unilateral lateral canal paralysis is suggestive of a vascular etiology (Kim et al, 1999). For diagnosis of BPPV with laboratory tests, it is important to have the ENG test done by a laboratory that can measure vertical eye movements. A magnetic resonance imaging (MRI) scan will be performed if a stroke or brain tumor is suspected. A rotatory chair test may be used for difficult diagnostic problems. It is possible but uncommon (5%) to have BPPV in both ears (bilateral BPPV).


 Updated: 12/07/08 Spanish

Causes Diagnosis Treatment




      The inner ear consists of three semicircular canals that contribute to a sense of balance. Over time, particles in the inner ear can break off and accumulate behind a membrane in the posterior canal. Moving the head in certain directions may cause particles to tug on hairlike sensors, triggering a type of dizziness called benign paroxysmal positional vertigo (BPPV).

      In most cases when it is found that a patient has BPPV, a noninvasive positioning procedure is used to clear the crystals out of the canal and deposit them back into the part of the inner ear where they belong.

      At Mayo (where proceedure was initialized/tested) there are several positioning procedures used to cure BPPV, including the modified Eply maneuver (canalith repositioning procedure or CRP), Semont's liberatory procedure, and a procedure using an electric circle bed that rotates the canals 360 degrees in a vertical plane.

Results of a study of the canalith repositioning maneuver for treatment of BPPV.

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