Traumatic benign paroxysmal positional vertigo caused by cannon fire.

Benign paroxysmal positional vertigo (BPPV) is the most common cause of vestibular vertigo. BPPV is characterised by brief episodes of vertigo that occur with movement of the head. Almost a quarter of cases of BPPV have a traumatic cause, but no cases of traumatic BPPV due to indirect trauma were found in the English literature.