BPPV onset after head position change includes a latent period of typically how long?

BPPV onset after head position change includes a latent period of typically how long?

• A. 0 seconds
• B. 1-30 seconds
• C. 31-60 seconds
• D. More than 60 seconds

Answer: (B)

In BPPV, vertigo and nystagmus typically begin after a short delay once the head change has been made because the dislodged otoconia must move within the semicircular canal and create endolymph flow to deflect the cupula. This process takes a brief time, so the symptoms have a small latency rather than being immediate. The most common latency range is about one to thirty seconds, which fits the typical canalithiasis mechanism. Latencies that are effectively immediate (0 seconds) or much longer (over 60 seconds or more) are not characteristic of the usual BPPV pattern.

In BPPV, vertigo and nystagmus typically begin after a short delay once the head change has been made because the dislodged otoconia must move within the semicircular canal and create endolymph flow to deflect the cupula. This process takes a brief time, so the symptoms have a small latency rather than being immediate. The most common latency range is about one to thirty seconds, which fits the typical canalithiasis mechanism. Latencies that are effectively immediate (0 seconds) or much longer (over 60 seconds or more) are not characteristic of the usual BPPV pattern.