[Mechanism of benign, peripheral, paroxysmal positional vertigo (BPPV)].

BACKGROUND

Positioning nystagmus of the peripheral benign type (BPPV) has long been considered to be due to cupulolithiasis-i.e. attachment of inorganic material to the cupula-of the posterior vertical semicircular canal. Meanwhile it has generally been recognized that not all characteristics of this type of nystagmus/vertigo can be explained by assuming a gravity-dependent reaction of the posterior canal. Canalolithiasis-i.e. floating material within the canal, heavier than endolymphe-of the posterior semicircular canal is now widely regarded as the cause of BPPV. Again, however, this is a concept far too simple to explain most of the properties of BPPV.

METHODS

Clearly defined, carefully performed positioning and positional maneuvers were carried out on 79 patients suffering from typical BPPV in order to reveal those positioning movements and positions necessary to elicit BPPV.

RESULTS

Detailed analysis of those positioning maneuvers necessary to elicit BPPV clearly reveals that canalolithiasis cannot be the cause of BBPV.

CONCLUSIONS

BPPV is a combination of positioning, and positional-dependent reactions in which the otolithic organs, and particularly the sacculus, seem to be involved.