By Sheelah Woodhouse, BScPT
What is BPPV?
Benign Paroxysmal Positional Vertigo (or BPPV) is the most common cause of vertigo, a false sensation of spinning.
- Benign – it is not life-threatening
- Paroxysmal – it comes in sudden, brief spells
- Positional – it gets triggered by certain head positions or movements
- Vertigo – a false sense of rotational movement
What happens during a BPPV episode?
BPPV is a mechanical problem in the inner ear. It occurs when some of the calcium carbonate crystals (otoconia) that are normally embedded in gel in the utricle become dislodged and migrate into one or more of the 3 fluid-filled semicircular canals, where they are not supposed to be. When enough of these particles accumulate in one of the canals they interfere with the normal fluid movement that these canals use to sense head motion, causing the inner ear to send false signals to the brain.
Fluid in the semi-circular canals does not normally react to gravity. However, the crystals do move with gravity, thereby moving the fluid when it normally would be still. When the fluid moves, nerve endings in the canal are excited and send a message to the brain that the head is moving, even though it isn’t. This false information does not match with what the other ear is sensing, with what the eyes are seeing, or with what the muscles and joints are doing, and this mismatched information is perceived by the brain as a spinning or vertigo sensation, which normally lasts less than one minute.