Interacoustics TRV chair - Characteristics of Positional Nystagmus

D-0125111-A – 2020/04
TRV chair – Instructions for Use - EN Page 28
4.2 Characteristics of positional nystagmus
The following table may be helpful when diagnosing BPPV from eye movements during positional tests:
Head Position
Duration
Rotation /
Horizontal
component
observed
Vertical
Component
Semicircular
Canal Involved
and BPPV Variant
Dix-
Hallpike/Sidelying
Right Ear Down
<30seconds
Right Torsional
Upbeating
Right Posterior
Canalithiasis
Dix-
Hallpike/Sidelying
Right Ear Down
>60 seconds
Right Torsional
Upbeating
Right Posterior
Cupololithiasis
Dix-
Hallpike/Sidelying
Right Ear Down
<30 seconds
Right Torsional
Downbeating
Left Anterior
Canalithiasis
Dix-
Hallpike/Sidelying
Right Ear Down
>60 seconds
Right Torsional
Downbeating
Left Anterior
Cupololithiasis
Dix-
Hallpike/Sidelying
Left Ear Down
<30 seconds
Left Torsional
Upbeating
Left Posterior
Canalithiasis
Dix-
Hallpike/Sidelying
Left Ear Down
>60 seconds
Left Torsional
Upbeating
Left Posterior
Cupololithiasis
Dix-
Hallpike/Sidelying
Left Ear Down
<30 seconds
Left Torsional
Downbeating
Right Anterior
Canalithiasis
Dix-
Hallpike/Sidelying
Left Ear Down
>60 seconds
Left Torsional
Downbeating
Right Anterior
Cupololithiasis
Horizontal Head
Roll Right/Left
<30 seconds
Geoptropic
(horizontal)
n/a
Greater response
when affected ear
is closest to the
ground 
indicates HC
canalithiasis
Horizontal Head
Roll Right/Left
>60 seconds
Ageotropic
(horizontal)
n/a
Greater response
when affected ear
is furthest from the
ground indicates
HC cupololithiasis
Whenever a position is selected following rotation of the secondary frame,
it is important to check that the mechanical locking system is correctly
engaged.
Before the primary frame is released, the patient should be informed what type of movement to expect as
well as of the probability of vertigo during the maneuver. Throughout the various maneuvers, it is
recommended that the operator keeps talking with the patient to provide reassurance.
WARNING