Positional Vertigo

Positional vertigo is vertigo that is triggered or worsened by specific head positions or head movements. The spinning or rotational sensation occurs when the head is placed in a particular orientation rather than spontaneously at rest. The most common and well-characterized cause of positional vertigo is benign paroxysmal positional vertigo (BPPV), in which displaced calcium carbonate crystals in the semicircular canals create false movement signals in response to head movement.

Positional vertigo from BPPV is typically brief, lasting less than one minute per episode, and is reproduced consistently by the same head position (such as rolling to one side in bed, tilting the head back to look upward, or bending forward). When nystagmus accompanies the vertigo during provocation testing, the direction and characteristics of the eye movement help identify which semicircular canal is affected.

Not all positional vertigo is caused by BPPV. Positional vertigo that lasts longer than one minute per episode, occurs in all head positions rather than specific ones, or is accompanied by other neurological symptoms warrants further investigation to rule out central causes such as posterior fossa tumors or demyelinating disease. Careful clinical assessment differentiates peripheral (inner ear) from central (brain) causes, as treatment approaches differ substantially.