Canalith repositioning procedure

The canalith repositioning procedure (CRP) is used to treat a common cause of vertigo called benign paroxysmal positional vertigo (BPPV). Let us understand more about BPPV and CRP.

BPPV is very common among all, with a lifetime estimated prevalence of 2.4%. This condition gets triggered when small calcium carbonate crystals (canaliths or otoconia) become dislodged from their normal position within the utricle of the inner ear and enter into one of the semicircular canals. This migration makes the inner ear send incorrect signals to the brain about the body's position, leading to vertigo. The condition can be managed by specific head movements and exercises. In some cases, BPPV is misdiagnosed as an inner ear infection, but it is a disorder of the inner ear that causes brief, intense episodes of vertigo. 

Symptoms of BPPV

The symptoms of BPPV can impact daily activities, and sometimes, patients present to the emergency room assuming the condition is a stroke. The common symptoms with BPPV include:

• Intense dizziness
• Spinning sensations
• Nausea
• Uncontrolled eye movements 

These symptoms are said to be short-lived, with an average of 39 days, however, seeking medical attention at the right time is advisable to achieve significant outcomes and reduce the risk of recurrent episodes. Canalith repositioning procedure (CRP) is considered to provide rapid treatment and minimize recurrences from BPPV. By taking an active role in CRP treatment, patients can regain control and improve their overall well-being. 

Understanding Canalith repositioning procedure (CRP)

CRP is a minimally invasive treatment and a highly recommended option for patients suffering from vertigo caused by benign paroxysmal positional vertigo (BPPV). CRP aims to move the dislodged crystals back to their original position, thereby improving the vertigo symptoms.

Indications for CRP

• Recurrent episodes of dizziness triggered by changes in head position, characteristic of BPPV.
• Positive results from positional testing, such as the Dix-Hallpike test, showing symptoms and characteristic nystagmus.

Procedure of CRP

The procedure starts with thorough assessment of by healthcare provider, typically an audiologist or ENT specialist. This includes a detailed study of patient history and physical examination focusing on the nature and triggers of vertigo.

Dix-Hallpike Test:

The Dix-Hallpike maneuver is often used to diagnose BPPV and identify the affected (left or right) ear and canal. The patient is moved back to the supine position with the head turned 45 degrees to one side and slightly extended backward. The clinician observes the patient's eyes for nystagmus (involuntary eye movements), which indicates BPPV.  If the patient gets positive for the Dix-Hallpike test, a series of movements are further guided on patient which includes:

Transition to Opposite Side:

After the previous step, the head of the patient is then moved to the opposite side of the unaffected ear by 90 degrees. This position is held for 30 seconds to 1 minute.

Further Rotation:

The patient’s head is rotated another 90 degrees, almost facing the floor, and held for the same duration.

Returning to the Sitting Position:

The patient is slowly brought back up to a sitting position, with their head still turned to the unaffected side. The head is then returned to its neutral position.

Benefits

CRP is highly effective, with a success rate of up to 90% in resolving symptoms of BPPV.

• The procedure is non-surgical or non-invasive and can be performed in a clinician's office.
• The procedure is inexpensive and does require specialized tools.
• Many patients experience immediate or rapid relief of vertigo symptoms.
• For persisting symptoms, the procedure can be repeated without significant risk.

Risks

• Some patients may experience temporary dizziness or nausea during or after the procedure.
• Due to the specific head movements required, some patients might experience neck stiffness or discomfort.
• In rare cases, CRP can dislodge otoconia into a different semicircular canal, potentially causing a different type of BPPV.

Post-Procedure instructions

Once the patient has completed CRP, the following instructions are provided: 

• To keep away or avoid sudden head movements for the rest of the day.
• Sleep with their head elevated for the next 24-48 hours.
• To prevent or stay away from lying flat on their back or on the affected side for a few nights.

Contraindications

Patients with severe neck problems or cervical spine instability should avoid CRP.

• Those who have undergone recent neck surgery may not be suitable candidates for this procedure.
• Patients with vascular insufficiency affecting the vertebrobasilar system should be carefully evaluated before undergoing CRP.
• Patients with severe or unstable vestibular conditions might not be appropriate candidates for this maneuver.

Evidence of Effectiveness

According to various studies, the therapy with Canalith Repositioning Maneuver (CRP) is found to be highly effective for treating Benign Paroxysmal Positional Vertigo (BPPV). Here are some of the study findings:

Key Findings

• Success Rate: Studies show that 61-80% of patients treated with CRP had their BPPV resolved, compared to only 10-20% in the control groups who received sham or placebo treatments.
• Number Needed to Treat (NNT): For CRP, the NNT is between 1.43 and 2.44. This means that for every 2 patients treated with CRP, 1 patient will experience complete relief from BPPV. This is a very strong effect, especially compared to other treatments in medicine. 

Appropriate Patient Selection for CRP

A crucial aspect of CRP's effectiveness is selecting the right patients. BPPV is one of the most common causes of positional vertigo, but in rare cases, positional vertigo can be due to structural brain abnormalities like Chiari malformation or brain tumors. These conditions can usually be identified by other abnormal examination findings or unusual nystagmus patterns that do not match those seen in BPPV. Additionally, patients with vestibular migraines can have dizziness with positional components, but they also lack the characteristic nystagmus patterns of BPPV.

CRP is ineffective for patients with other causes of dizziness or vertigo, such as vestibular neuritis, Meniere’s disease, orthostatic hypotension, or panic attacks. Therefore, proper use of CRP requires careful patient selection, accurate identification of the affected ear, correct positioning during the maneuver, and appropriate timing between the steps of the procedure.

Limitations of CRP

• Using CRP for patients who do not have BPPV (incorrect diagnosis).
• Incorrectly performing the individual components of CRP.

By ensuring precise diagnosis and proper technique, the canalith repositioning procedure can be an effective treatment for patients with benign paroxysmal positional vertigo.