These symptoms are characteristic of BPPV, with neurological examination indicating involvement of the left posterior semicircular canal.
Recurring short episodes of vertigo following trauma are not uncommon. In BPPV the symptoms of pseudo rotation of the environment occur on movement of the head in certain positions. Post-traumatically, tiny fragments of debris (otoconia), in fluid of the inner ear semicircular canals, are caused to move about. Otoconia are made up of calcium carbonate crystals that arise from within the utricle, a fluid filled chamber forming part of the labyrinth. If the head is struck, otoconia particles may be jettisoned and become free floating (canalithiasis) in the semicircular canals. With movement of the head, these fragments are swept along in the fluid and brush against hairs that line the semicircular canals to create a false sense of motion. The result to the patient is a sensation of vertigo. Clinically, this is apparent as nystagmus after a characteristic latency of a few seconds, with rapid resolution (usually 20–30 s) once the head is still.
When idiopathic in origin, BPPV usually occurs in older people and is more common in women than men. As in our case, the posterior semicircular canal is affected in 85–95% of cases, probably in relation to its position at the lowest point, where the otoconia are likely to collect.2
We have shown that the diagnosis can be confirmed by manoeuvres consisting of controlled movement of the patient’s head in the plane of the semicircular canal thought to be responsible.
An understanding of these vestibular rehabilitation techniques has now resulted in drug therapies being considered largely inappropriate in this condition.3
- Benign paroxysmal positional vertigo (BPPV) is a common and treatable condition that is frequently missed.
- BPPV is a common sequelae to significant head trauma, but can also occur after mild trauma, which accounts for around 18% of cases.4
- BPPV is diagnosed using the Dix–Hallpike manoeuvre.
- BPPV is amenable to therapies using one of several restorative vestibular manoeuvres.