Diagnosis of Single- or Multiple-Canal Benign Paroxysmal Positional Vertigo according to the Type of Nystagmus
Table 1
Diagnosis of the involved semicircular canal and the side of involvement, according to the appropriate diagnostic maneuver. SC: semicircular canal; R: right; L: left; P: posterior; A: anterior; H: horizontal; BPPV: benign paroxysmal positional vertigo.
(a) Vertical SC canals
Involved SC canal
Diagnostic maneuver
Paroxysmal positioning nystagmus
Vertical
Torsional
P-BPPV R
Dix-Hallpike R (+)
Upbeating
Counterclockwise
Dix-Hallpike L (−)
No nystagmus
P-BPPV L
Dix-Hallpike R (−)
No nystagmus
Dix-Hallpike L (+)
Upbeating
Clockwise
A-BPPV R
Dix-Hallpike R (+)
Downbeating
Counterclockwise
Dix-Hallpike L (+)
Downbeating
Counterclockwise
A-BPPV L
Dix-Hallpike R (+)
Downbeating
clockwise
Dix-Hallpike L (+)
Downbeating
Clockwise
(b) Horizontal SC canals
Direction of nystagmus
Intensity of nystagmus
Pathogenetic mechanism
H-BPPV R
Supine roll test R (+)
Geotropic
More intense
Canalolithiasis
Supine roll test L (+)
Geotropic
Less intense
H-BPPV R
Supine roll test R (+)
Apogeotropic
Less intense
Cupulolithiasis or canalolithiasis of the short arm of the horizontal SC
Supine roll test L (+)
Apogeotropic
More intense
H-BPPV L
Supine roll test R (+)
Geotropic
Less intense
Canalolithiasis
Supine roll test L (+)
Geotropic
More intense
H-BPPV L
Supine roll test R (+)
Apogeotropic
More intense
Cupulolithiasis or canalolithiasis of the short arm of the horizontal