Which semicircular canal is most often involved in posterior canal BPPV?

Which semicircular canal is most often involved in posterior canal BPPV?

• A. Anterior canal
• B. Lateral canal
• C. Superior canal
• D. Posterior canal

Answer: (D)

BPPV most often involves the posterior canal because gravity and canal orientation make it easiest for detached otoconia to settle into and move within this canal during everyday head positions. When the head is turned back and tilted (as in lying down and looking to the side), debris in the posterior canal is readily drawn by gravity toward the ampulla, where its movement stimulates the vestibular hair cells briefly and causes vertigo. This movement also produces the classic nystagmus pattern described in Dix-Hallpike testing: a brief vertigo with upbeating, torsional eye movements toward the affected side. The anatomy of the posterior canal aligns with common postural changes, so debris are most likely to end up there and to produce the typical BPPV symptoms. Other canals can be involved, but they’re less commonly affected due to their different orientations and how gravity influences debris within them.

BPPV most often involves the posterior canal because gravity and canal orientation make it easiest for detached otoconia to settle into and move within this canal during everyday head positions. When the head is turned back and tilted (as in lying down and looking to the side), debris in the posterior canal is readily drawn by gravity toward the ampulla, where its movement stimulates the vestibular hair cells briefly and causes vertigo. This movement also produces the classic nystagmus pattern described in Dix-Hallpike testing: a brief vertigo with upbeating, torsional eye movements toward the affected side. The anatomy of the posterior canal aligns with common postural changes, so debris are most likely to end up there and to produce the typical BPPV symptoms. Other canals can be involved, but they’re less commonly affected due to their different orientations and how gravity influences debris within them.