Canalith Repositioning Procedure (CRP)
What is a canalith repositioning procedure (CRP)?
A canalith repositioning procedure (CRP) is a treatment for benign paroxysmal positional vertigo (BPPV), the most common cause of vertigo.
What is benign paroxysmal positional vertigo (BPPV)?
The letters of the term “BPPV” stand for:
- Benign: of no danger to health
- Paroxysmal: happening in sudden, brief spells
- Positional: triggered by particular head movements or positions
- Vertigo: an internal sense of irregular or whirling motion either of yourself or of objects around you
The cause of BPPV is the displacement of small crystals of calcium carbonate (also known as canaliths) in the inner ear.
The crystals become trapped in the inner ear’s fluid-filled semicircular canal. Usually the posterior semicircular canal is affected because its structure works with the pull of gravity.
The semicircular canals are normally not sensitive to head and body position changes. With BPPV, however, head and body movements such as lying down cause the crystals to move, which stimulates nerve endings inside the semicircular canals.
The nerves send false signals to the brain, causing dizziness and other unsettling symptoms of vertigo including nausea, vomiting, disorientation or instability, as well as a back-and-forth rhythmic eye movements called nystagmus.
How does the canalith repositioning procedure (CRP) work?
CRP uses a series of changes in head position to move the detached crystals in the inner ear out of the semicircular canals into an adjacent structure called the utricle, a sac where the crystals first formed. Once back in the utricle the crystals can either reattach, dissolve, be broken up or move somewhere else where they won’t cause symptoms.
Who needs to have a canalith repositioning procedure (CRP)?
Anyone with BBPV who can go through the procedure safely may benefit from it. If BBPV returns after CRP, the procedure can be used again to treat recurrences.
What conditions are treated with a canalith repositioning procedure (CRP)?
CRP is used only for the treatment of BBPV. An examination of the patient should rule out other possible causes of vertigo before CRP is used.
Other causes of vertigo could include:
- An abnormal brain structure
- Certain kinds of migraine headaches
- Vestibular neuritis (a type of inner-ear infection)
- Meniere’s disease (a progressive disease of the inner ear, causing ringing in the ears among other symptoms)
- Orthostatic hypotension (low blood pressure upon standing up)
- Panic attacks
What are the different types of canalith repositioning procedure (CRP)?
There the two most common types of CRP available to treat BPPV and called the Epley maneuver and the Semont-Liberatory maneuver. Which one is chosen depends on the results of a Dix-Hallpike test (see next section).