Differential diagnosis between bppv and mppv in direction-changing positional
Abstract
For many years, it has gave description as MPPV (Malignat Paroxysmal Positiona
l Vertigo) that direction-changing positional nystagmus is caused by central n
erve system disorders
Recently it became evident that direction-changing positional nystagmus is cau
sed by horizontal canal type of BPPV (HC-BPPV).
The clinical signs of HC-BPPV and MPPV are closely resembled. They have short
latent time and long duration, no fatigability. So we desire the effective cli
nical examination for differential diagnosis eagerly.
Although vertigo in most cases of BPPV disappears within a month, we are often
confused refractory vertigo with direction-changing positional nystagmus.
Our investigation of them reveals that the visual suppression test and inspect
ive check for the direction change in nystagmus are useful for differential di
agnosis.
