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).
What happens before a canalith repositioning procedure (CRP)?
A medical examination will determine if the patient is a good candidate for CRP. People with certain health conditions should not undertake the procedure. These conditions include existing inner ear problems that could be made worse with CRP, detached retina, certain vascular (blood vessel) disorders and esophageal reflux disease.
A Dix-Hallpike test is administered to confirm a diagnosis of BPPV. The patient is laid back onto an examination table in such a position that canaliths (crystals), if present, will trigger vertigo and nystagmus. If the test is positive it will also show if the canaliths are in the right or left ear, and where they are within those. This helps determine the exact movements that will help the most during CRP.
The procedure can be performed in a doctor’s office and usually takes about 15 minutes. An anti-nausea medication may be given beforehand.
What happens during a canalith repositioning procedure/treatment?
CRP uses a specific pattern of head and body movements. It must be delivered by an expert in the procedure to exclude those who are not good candidates, and guard against injury during the procedure.
- Step 1 – The patient is laid on the back onto an examination table, with the head hanging over the back edge of the table. The patient’s head is turned in the direction of the affected side.
- Step 2 – The patient remains in this position for 30 seconds.
- Step 3 – The head is turned in the other direction to the unaffected side for 30 seconds.
- Step 4 – The head is turned again to a nearly face-down position for 30 seconds. The patient’s body will likely have to be repositioned from lying on the back to lying on the side to be able to accommodate this head movement.
- Step 5 – The patient is brought back to a sitting position. When the patient sits up quickly the canaliths fall out of the canal, back into the middle chamber of the inner ear where they do not cause symptoms.
The exact head movements chosen and the amount of time between movements are based on the location of the crystals within the ear and are determined by the medical team giving the procedure.
What happens after a canalith repositioning procedure (CRP)?
Best practice recommendations strongly advice against post-treatment restrictions after CRP for posterior canal BPPV. There is limited medical evidence to support avoiding head movements, sleeping in a reclined position after treatment or avoiding sleeping over the affected ear for days following treatment. However, some consideration of post-treatment restrictions may be made in some cases such as frequently recurring BPPV.
Risks / Benefits
What are the advantages of a canalith repositioning procedure (CRP)?
CRP is a unique medical procedure because it does not require any special tools or equipment other than an examination table, and is not invasive in any way. Once the position of the canaliths is determined, the patient is led through the correct series of movements and should find relief quickly.
What are the complications of a canalith repositioning procedure (CRP)?
Possible complications of CRP include injury to the neck or back, or crystals being dislodged and moving to another semicircular canal.
Is a canalith repositioning procedure (CRP) safe?
Reviews of CRP find it to have a very high level of effectiveness. A number of studies have been conducted showing that 85-90 percent of patients treated with CRP were relieved of the symptoms of BPPV, compared to only 10-20 percent of untreated patients who found relief.
Recovery and Outlook
What is the long-term outlook for patients after canalith repositioning procedure (CRP)?
CRP cures vertigo in about 85 percent of the cases in which it is used. Recurrence of symptoms is infrequent however additional treatments are sometimes needed. CRP may be used again if symptoms return.