Reading time: 2 minutes
The DHM Explained In This Short 3 Minute Video
This test is performed with the patient seated on an exam table, legs extended. The clinician simultaneously rotates the patient’s head 45 degrees and quickly brings the patient into a supine position with their head extended off the table to 30 degrees. The position is held for at least 15 seconds and the patient is asked to report any vertigo while the clinician observes for nystagmus. The patient is returned to the upright position and the test is repeated on the opposite side.
A positive test includes the reproduction of dizziness, nausea, and/or nystagmus. Posterior canal lesions will result in up-beating nystagmus, while anterior canal lesions produce down-beating nystagmus. The downward-facing ear is the side being tested; i.e., if the right posterior semicircular canal is involved, symptoms develop when the head is initially rotated toward the right.
One little-known caveat to this test is the difference between subjective and objective BPPV. The Dix-Hallpike Maneuver may produce vertigo and nystagmus together or in isolation.
Objective BPPV= BOTH Vertigo and Nystagmus
Subjective BPPV= Vertigo Only
- In a randomized clinical trial analyzing the effectiveness of the Epley maneuver, it was only effective in patients who had both vertigo and nystagmus at baseline (Objective BPPV).
- It is possible that the dislodged otolithic particles are sufficient to cause vertigo but do not stimulate the cilia enough to cause nystagmus.
- It is also possible that the examiner is unable to detect mild nystagmus without specialized equipment. For example, primary care offices have higher rates of false-negative results (60% and 80%) due to a lack of the proper diagnostic equipment like Frenzel glasses.
- Finally, look for other causes of vertigo—like cervicogenic vertigo.
ChiroUp Tip: there is a significant correlation between the habitual sleep side and the affected ear. Patients should be encouraged to sleep with the affected side up.
Ready to learn more?
With ChiroUp, you can access resources like these when you sign up for our 14-day free trial.
We are sorry that this post was not useful for you!
Let us improve this post!
Tell us how we can improve this post?