Dizziness and TBI: What's the Connection?

The posterior canal (PC) is the most commonly affected semicircular canal, mainly due to its orientation relative to gravity, and this is followed by the horizontal canal (HC). The anterior canal is rarely affected by otoconia. When vertical head movements and rolling over in bed to one side are the predominant trigger(s), PC-BPPV is usually the culprit. A crescendo-decrescendo upbeat-torsional (top poles beating toward the lowermost or affected ear) nystagmus should be seen with the Dix-Hallpike maneuver, with nystagmus and vertigo lasting <30-60 seconds.