What is BPPV and what causes it?
Benign paroxysmal positional vertigo (BPPV) is an inner-ear disorder. “Benign” means harmless and “paroxysmal” refers to a sudden attack or recurrence. People with BPPV experience brief periods of vertigo (a spinning sensation) tied to their movement. It typically occurs when they turn over in bed, sit up after lying down or bend over quickly. Each episode lasts only a few seconds. While it’s not a serious disorder, the symptoms are unpleasant.
BPPV affects approximately 2 out of 100 people and usually occurs in people older than 50 years. It’s more common in women than men and can also result from a head injury. Most of the time the exact cause of BPPV is unclear, but doctors do know that detached or free-floating otoliths (ear stones) result in vertigo.
Ear stones are calcium carbonate particles attached to hair cells in the utricle and saccule structures, located in the vestibule. The vestibule and semicircular canals form the vestibular (or balance) system in the inner ear. When the head moves, ear stones pull on the hair-like structures to bend it in the direction of gravity. Detached ear stones can move into the semicircular canals and make you feel dizzy.
What are the semicircular canals?
The semicircular canals are interconnected tubes filled with liquid. The vestibule responds to gravity or changes in the position of the head, while the semicircular canals respond to head rotation. There are three canals: posterior, horizontal and anterior. The posterior and anterior semicircular canals are both positioned vertically, but the anterior canal is the highest point.
How is BPPV diagnosed?
To diagnose BPPV, a specialist will first review the patient’s history and then perform a Dix-Hallpike test. This test is designed to trigger vertigo. The doctor will have the patient sit upright on a flat surface. Then, head turned to the side, the patient will lie down quickly. Patients with BPPV will experience vertigo and nystagmus (involuntary eye movement). Nystagmus is a typical diagnostic indicator of the presence of positional vertigo because it reflects a coordination issue between balance and sight. The specialist will take note of the direction of the eye movement to determine which canal is affected.
BPPV mostly affects the posterior semicircular canal, but the horizontal and anterior canals can also be affected. The anterior canal is the least likely to be affected. The most common type of BPPV is canalithiasis (free-floating ear stones). The second and very rare type is cupulolithiasis. In this case, the ear stones become fixed in a semicircular canal and weigh down the cupula, a jelly-like structure.
How is BPPV treated?
Repositioning manoeuvres can be performed by a doctor to help direct the ear stones back to the utricle and saccule structures in the vestibule.
- Sit upright on an examination table in front of the doctor, head turned 45° to the left or right (it depends on the affected ear).
- Quickly lie down sideways on the affected side, keeping your head in the same position.
- After 2-3 minutes, quickly switch 180° and lie down on the unaffected side, keeping your head in the same position.
- After another 2-3 minutes, slowly return to sitting upright and wait for a few minutes.
- Sit upright, legs outstretched, on the examination table.
- Turn your head 45° towards the affected ear and quickly lie back, so that your head hangs over the edge of the table. Stay in this position until vertigo and nystagmus have disappeared (at least 1 minute).
- Now turn your head towards the unaffected side and hold this position for 1 minute.
- Next, turn sideways and lie on the shoulder of the unaffected side, keeping your head in the same position.
- After another minute, go back to sitting upright, head tipped slightly to the unaffected shoulder. Return your head to a level position.
If this treatment doesn’t work, the Brandt-Daroff exercises may help:
- Sit upright.
- Move into the lying position on one side, head turned 45°.
- Remain in this position for about 30 seconds and sit upright again.
- Repeat on the other side.