Translating The Biomechanics Of Benign

Translating the Biomechanics of
Benign Paroxysmal Positional Vertigo
to the Differential Diagnosis and Treatment
Combined Sections Meeting
Las Vegas, NV – February 3-6, 2014
Richard Rabbitt, PhD,
University of Utah, Salt Lake City, UT
Janet O. Helminski, PT, PhD,
Midwestern University, Downers Grove, IL
Janene Holmberg, PT, DPT, NCS,
Intermountain Hearing and Balance, Salt Lake City, UT
Translating the Biomechanics of
Benign Paroxysmal Positional Vertigo
to the Differential Diagnosis and Treatment
Objectives: The participants will be able to:
(1) Describe normal fluid dynamics, afferent firing, and anatomical alignment
of the semicircular canals.
(2) Describe the pathological biomechanics of BPPV.
(3) Interpret patterns of nystagmus observed during positional testing and
particle repositioning maneuvers.
(4) Determine the “ideal” particle repositioning maneuver based on
biomechanics of BPPV.
Normal Anatomy and Physiology of the
Semicircular Canals
MRI of Right Membranous Labyrinth and Vestibular N.
Utricle
Saccule
Vestibular Nerve
Ampulla LC
Ampulla PC
http://commons.wikimedia.org/wiki/File:Inner_ear_Cho
chlea_and_vestibular_system_115700_MAIP3.png
Semicircular Canals-Crista Ampullaris and Cupula
The fluid filled canals normally act to
detect rotation of the head.
Rotation of the head causes deflection
of the sensory hair cells located within
the crista ampullaris.
The hair cells are embedded within a
gelatinous membrane – the cupula.
Photomicrograph of crista ampullaris and
its cupula. Note that the cupula is
attached to the ampullary roof.
(Gacek , 2008)
Hair Cells – Sensory Transducer
Hair cells consist of stereocilia and kinocilium. Defection of hair cells:
•AmpulloFUGAL- towards the kinocilium - excites CN VIII.
•AmpullaPEDAL - away from the kinocilium - inhibits CN VIII
Position of Kinocilium within the Ampulla
Effects Neural Firing of CN VIII
In the vertical canals:
• flow of endolymph away from
ampulla excites the nerve.
• flow towards the ampulla
inhibits the nerve.
In the lateral canals:
• flow of endolymph towards the
ampulla excites the nerve
• flow away from the ampulla
inhibits the nerve.
Each canal generates eye movements in opposite directions.
Orientation of Initial Ampullary Segment in the
Upright Position
Illustrated for Left Membranous Labyrinth
– PC - 20° below horizontal.
AC Ampullary
Segment
– AC – almost vertical (70° with
respect to earth horizontal).
– LC – 20-30° naso-occiptal angle.
LC Ampullary Segment
PC Ampullary Segment
Bertholon P et al. J Neurol Neurosurg Psychiatry 2002;72:366-372.
©2002 by BMJ Publishing Group Ltd.
Comparison of Human Canal Planes using MRI
Orientation of Canal Planes
• PC - 51° from the sagittal plane
35°
•AC - 35° from the sagittal plane
51
°
Suzuki K., Masukawa a., et al., 2010
Mathematical Model of Human Semicircular Canal
Geometry Based on CT Scans
Canal planes are curvilinear not flat.
Bradshaw AP, Curthoys IS, Todd MJ, Magnussen JS, Taubman DS, Aw ST, Halmagyi
GM. A Mathematical model of human semicircular canal geometry: a new basis for
interpreting vestibular physiology. JARO. 2010;11:145-159.
Canal Influences Pair of Extraocular Muscles
Extraocular muscles that receive direct excitatory contributions
(Illustrated for left eye).
•Anterior Canal influences
– i-Superior Rectus
– C-Inferior Oblique
AC
LC
•Posterior Canal influences
– i-Superior Oblique
– C-Inferior Rectus
•Lateral Canal influences
– i-Medial Rectus
– C-Lateral Rectus
PC
HC
LC
AC
PC
www.gimbeleyecentre.com/images/eye_muscles.gif
Vestibular Ocular Reflex Pathway
Excitatory and Inhibitory Connections.
Wikimedia.org
Lateral Canal Stimulation
Right
Left
MacDougall, McGarvie, Halmagyi, Curthoys, and Weber, 2013
RALP Stimulation
Right Anterior – Left Posterior
Right
Left
MacDougall, McGarvie, Halmagyi, Curthoys, and Weber, 2013
LARP Stimulation
Left Anterior – Right Posterior
Right
Left
MacDougall, McGarvie, Halmagyi, Curthoys, and Weber, 2013
Dr. Rabbitt – Slides 1-22
Pathological Biomechanics of
Benign Paroxysmal Positional Vertigo
Saccule
Utricle
http://commons.wikimedia.org/wiki/File:Inner_ear_Chochlea_and_vestibular_system_115700_MAIP3.png
Maculae – Hair Cells, Otolith Membrane, Otoconia
Otoconia weights the sensory membrane. The weighted sensory
membrane acts to detect gravitational forces on the head.
Increased magnification of macula. Note
hair cells and otolith membrane.
http://www.cytochemistry.net/microanatomy/Ear/org
anization_of_the_inner_ear.htm
Electron Microscope of Calcite
particles (otoconia) (Everett,
Belyantseva, et al, 2001)
Otoconia
Otoconia composed of organic matrix and minerals (calcium carbonate).
The matrix is identical to matrix of otolithic membrane.
http://hmg.oxfordjournals.org/co
ntent/10/2.cover-expansion
Intact human otoconia surrounded by organic
matrix (Walther, Wenzel et al., 2013)
Age-Related Changes of the Morphology of
Human Otoconia
Stages of degeneration of human otoconia. Otoconia bodies are
pitted, fissured, penetrated or broken into several fragments.
(Walther, Wenzel, et al.., 2013).
Age-Related Changes of the Morphology of Otoconia
A
Utricular Macula
A. Middle-aged rat.
B. Aged rat. Giant otoconia outer
margin.
B
Field emission scanning electron microscopy
(FESEM) micrographs.
Scale bar = 100µm.
Jang, Hwang, Shin, Bae, Kim, 2006
Age-Related Changes of the
Morphology of Otoconia
Linking filaments
A. Interconnecting fibrils
intact human otoconia
(Walther, Wenzel, et al..,
2013).
B. Weakened and broken
fibrils in aged rats (Jang,
Hwang, Shin, et al., 2006)
Field emission scanning electron
microscopy (FESEM) micrographs.
Scale bar = 2µm.
A
Mechanisms of BPPV
•Otoconia that normally
weights the membrane
becomes dislodged and
settles into the canals
changing the dynamics of the
canals.
Model of Cupulolithiasis
Bullfrog labyrinth – otoconial mass on cupula.
Kitajima, 2012
Model of Cupulolithiasis
Otoconia attached to cupula
Characteristics of Ocular Nystagmus
• Brief latency before onset of nystagmus because of
weight of the particles on the PC cupula (Rajguru
et al., 2004).
• Maintained activation of PC when the orientation
of the head is changed relative to gravity (Rajguru
et al., 2004).
• The effect builds up gradually over time to its value
(20 s) (Hain,et. al., 2005).
• Any reduction in afferent input would be the result
of adaptation by the hair cell afferent complexes
(Rajguru et al., 2004).
• The same otoconia produce only 1/3 as much
nystagmus as canalithiasis (Rajguru et al., 2004;
Hain, et. al., 2005).
Reorientation of the canal
relative to gravity deflects the
cupula. (Korres et al., 2004)
Model of Canalithiasis
Bullfrog labyrinth – otoconia inserted into PC.
Kitajima, 2012
Model of Canalithiasis
Characteristics of Ocular Nystagmus
• Latency – movement of detached
otoconia through the ampulla (Rajguru et
al., 2004; Hain et. al., 2005).
• A group of smaller particles showed
longer latencies and larger responses (up
to 80 s) than a single large particle of the
same total mass (Rajguru et al., 2004).
• Takes 25 s for an otoconium to traverse
one quarter of the canal (Hain et al., 2005).
• Small particles in constant contact with
the wall while it sediments produces no
nystagmus (Hain et al., 2005)
Model of
Canalithiasis and Cupulolithiasis
Bullfrog labyrinth – otoconial mass in long arm of PC and on cupula.
Kitajima, 2012
Dr. Rabbitt – Slides 23-30
Positional Testing
Diagnosis of BPPV
Clinical Practice Guidelines
American Academy of
Otolaryngology Head and
Neck Surgery (Bhattacharyya
et al., 2008) and American
Academy of Neurology (Fife et
al., 2008). Diagnosis based on
both:
A. History
B. Findings on Positional
Testing:
–
–
Subjective (Symptoms)
Objective (Nystagmus)
History – Critical to Differential Diagnosis Process
If getting out of bed and rolling over in bed is
positive, patient 4.3 times more likely to have
BPPV (Whitney, Marchetti, & Morris, 2005).
If vertical canals involved, symptoms evoked when
the patient:
– Looks up (top shelf syndrome – PC involved)
– Moves head quickly
– Bends
– Bends forward to read (AC involved)
If LC involved, symptoms evoked when the patient:
– Checks mirrors while driving
– Turns head in the horizontal plane while
ambulating
– Bend forward in pitch plane
Dix-Hallpike Test (DHT)
•Patient wears Frenzel goggles or videooculography to prevent visual suppression of
ny.
•Avoid use of vestibular suppressant
medication that suppresses ocular ny.
•Maintain each position for at least 45 s.
•Re-evaluate >24 hours after the initial
treatment procedure to avoid the fatiguing
response (von Brevern et al., 2006).
•Psychometrics (Halker, Barrs, et al., 2008)
• Estimated sensitivity 79% (95% CI 65-94)
• Estimated specificity 75% (95% CI 33-100)
Horizontal
Vertical
DHT - illustrated for head right
position only (A-B). Illustrated
eye position traces (C).
Alternative to DHT - Sidelying Test (Cohen, 2004).
•Evaluates sensitivity of PC and AC if
patient is unable to lie supine or move
into neck extension.
•Same positions as Brandt-Daroff
Exercises (Brandt et al, 1980).
Findings on DHT:
Diagnostic Criteria for PC-BPPV
• Vector of PC ocular nystagmus primarily torsional (towards the dependent
ear) and upward directed (Aw et al., 2005).
• Characteristics of Nystagmus
– 1- to 40- second latency before the onset of vertigo and nystagmus
(Brandt et al, 1980; Epley, 1980; Herdman, 1990).
– Vertigo and nystagmus < 60 seconds in duration (Baloh et al., 1993).
– Fatigues with repeated positioning (Baloh et al., 1993).
Debris Right PC
Debris Right PC
Findings on DHT Suggest PC-BPPV
Pattern of Nystagmus suggests Cupulolithiasis
Findings on DHT Suggest PC-BPPV
Pattern of Nystagmus suggests Canalithiasis
Debris within Ampulla
Findings on DHT Suggest PC-BPPV
Pattern of Nystagmus suggests Canalithiasis
Debris within Long Arm
Findings on DHT:
Diagnostic Criteria for AC-BPPV
• Vector of AC Ocular Nystagmus:
• Primarily downward directed
• Small torsional component or no torsion (50% of patients). Direction
of torsion towards ear involved.
• geotropic-axis of the lowermost ear or
• apogeotropic-axis of the uppermost ear
• Characteristics of Nystagmus (Berthonlon et al., 2002)
• 1- to 5- second latency before the onset of vertigo and nystagmus.
• Vertigo and nystagmus < 60 seconds in duration.
• Fatigues with repeated positioning.
Key: Right Head Hanging Position may
activate both AC’s.
Findings on DHT:
Diagnostic Criteria for AC-BPPV
• The straight head hanging position
(30°of extension) of the DHT
enables otoconia to clear the
curvature of the long arm of the AC.
•A minimum of 60° of extension is
needed to clear the curvature of the
AC (Kim and Amedee, 2002; Crevits,
2005).
4
Findings on DHT Suggest AC-BPPV
Side Involved Unknown
Findings on DHT Suggest AC-BPPV
Torsion Towards Involved Ear
Dix-Hallpike Test (DHT)
Key: To evaluate the PC and AC the
head needs to be extended below
the horizon to evoke nystagmus.
DHT - illustrated for head right position
only (A-B).
Dr. Rabbitt – Slides 31-40
Particle Repositioning Maneuvers for
Posterior Canal BPPV
Critical Steps for Successful Rx of PC-BPPV
Canalith Repositioning Procedure (CRP) –
Modified Epley Maneuver
• Initial position adequate neck
extension (head below horizon) to
allow otoconia to settle into the long
arm of the canal.
•Maintain neck extension during
initial roll (B-C) to enable debris to
roll away from ampulla.
•A 180° turn of the head is required
to effectively clear the debris (B and
D).
(Rajguru, Ifediba et al., 2004).
CRP - illustrated for treatment of right PC.
Critical Steps for Successful Rx of PC-BPPV
Canalith Repositioning Procedure (CRP) –
Modified Epley Maneuver
• The head may be elevated 15° from
the horizon in position D to prevent
canal conversion to the AC and for
comfort.
•The patient returns to sitting from
lying on the uninvolved side .
• The head is flexed 36° in the chin
down forward position to allow debris
to settle lowest part of utricle.
(Rajguru, Ifediba et al., 2004).
CRP - illustrated for treatment of right PC.
Critical Steps for Successful Rx of PC-BPPV
Canalith Repositioning Procedure (CRP) –
Modified Epley Maneuver
Key to Success: Position of
plane of PC relative to gravity
not speed.
CRP - illustrated for treatment of right PC.
If Patient Can’t Tolerate Modify CRP –
Use Tilt Table
•Use tilt table to position canal
plane within plane of gravity
maintaining position of head
relative to trunk and modifying
position of body.
Pattern of Nystagmus Predicts Outcome of CRP Successful Resolution
Pattern of Nystagmus Predicts Outcome of CRP
•
Successful CRP. The angular velocity of the debris is always in the
same direction causing an orthotropic pattern of ny (Korn,
Dorigueto, et al, 2007).
Pattern of Nystagmus Predicts Outcome of CRP Failure - No Resolution
Pattern of Nystagmus Predicts Outcome of CRP
•
Failed CRP. The angular velocity of the debris reverses direction
causing a reversal in the direction of ny (Korn, Dorigueto, et al,
2007).
Average Short Term Success Rate of CRP
Average short term success rate of Canalith Repositioning Procedure
in RCT(*) and quasi RCT (Helminski, et. al., 2010).
Study
Number
resolved/
Number in
study
Percent
Resolve
Odds Ratio Confidence Intervals
Lynn et al., 1995*
16/18
89
22.0(3.41-141.73)
Von Brevern et al.,
2006*
28/35
80
37.33(8.75-159.22)
Froehling et al., 2000
16/24
67
3.20(1.00-10.20)
Sherman et al., 2001
27/33
82
24.75(4.31-142.02)
Average
87/110
80 + 9
Note: Variability in study by Froehling et al., 2000 may be due to
clinical expertise of the study personnel.
Liberatory or Semont Maneuver
(Semont, Freyss et al. 1988)
Illustrated for treatment of the left PC (Radtke et al., 2004)
Liberatory or Semont Maneuver
(Semont, Freyss et al. 1988)
•Liberatory Maneuver. The duration of the 180 ° whole-body swing needs to be less
than 1.5 seconds (Faldon and Bronstein, 2008).
– Slow 180° acceleration traces a counterclockwise path - particles trapped
behind cupula.
– Fast 180° acceleration plots a complete clockwise rotation - particles
evacuated.
56
Liberatory Maneuver (Semont, Freyss et al. 1988)
•Duration < 1.5 seconds.
5
7
Pattern of Nystagmus Predicts Outcome of LM:
Successful Resolution
Pattern of Nystagmus Predicts Outcome of LM:
Failure No Resolution
Average Short Term Success Rate of Liberatory Maneuver
Randomized controlled trials have evaluated the effectiveness
of the Liberatory maneuver versus a control. Limited number
of studies suggest LM more effective than a control.
Study
Number
resolved/
Number in
study
Percent
Resolve
(%)
Odds Ratio - Confidence
Intervals
LM
Control
151/174
0/168
87
0
2172(131-36078)
LM
Control
55/65
9/63
85
14
33(12-88)
Mandala et al., 2012
Chen et al, 2012
Comparison of CRP versus Liberatory Manuever
Quasi RCT at short term follow-up of 1 week (Helminski, et. al., 2010)
Study/Intervention
Groups
Number
resolved/
Number in
study
Percent
Resolve
(%)
Odds Ratio - Confidence
Intervals
CRP
LM
43/46
46/50
93
92
0.80(0.17-3.79)
Soto Varela et al, 2001*
CRP
LM
30/42
26/35
71
74
1.16(0.42-3.18)
Radtke et al., 2004**
Self-admin. CRP
Self-admin. LM
35/37
19/33
95
58
0.08(0.02-0.38)
Tanimoto et al., 2005*
CRP only
CRP+Self-admin.CRP
28/39
36/40
72
90
3.54(1.02-12.30)
Massoud et al, 1996*
* Standard treatment CRP.
** Standard treatment self-administered CRP .
What About Brandt-Daroff Exercsies?
Evidence does not Support Use of Brandt-Daroff Exercises
as Primary Treatment of BPPV
• Debris moved within a 90°
segment of the canal. A 360°
turn of the head in the plane of
the canal is required to
effectively clear the debris
(Rajguru et al., 2004; Faldon
et al., 2008).
• Daily routine of Brandt-Daroff
exercises does not affect the
time to recurrence or rate of
recurrence of BPPV
(Helminski, et al., 2005).
• May cause multi-canal BPPV.
Evidence does not Support Use of Brandt-Daroff Exercsies
as Primary Treatment of BPPV
Randomized controlled trial have evaluated the effectiveness of the Brandt-Daroff exercises
versus self-administered particle repositioning procedures and control. Findings suggest BrandtDaroff exercises are as effective as a control at 1 week (Zhang et al., 2012).
Study
Zhang et al., 2012
self-administered CRP
self-administered LM
BD
Control
Number
resolved/
Number in
study
Percent
Resolve
(%)
39/45
23/43
14/40
6/40
87
53
35
15
*Brandt-Daroff exercises versus control
χ2
3.35, p>0.05*
Further Evidence needed to Support use as
Secondary Treatment of BPPV
• Break-up debris to dissolve particles.
• “Central habituation effect” to resolve residual symptoms
and phobia (Cohen, 2005).
Dr. Rabbitt – Slides 41-50
Particle Repositioning Maneuvers for
Anterior Canal BPPV
Maneuvers Designed for AC-BPPV
Neck Extension - If Side Involved is Unknown
A minimum of 60° of extension is needed
to clear the curvature of the AC (Kim and
Amedee, 2002; Crevits, 2005).
Neck Extension (Helminski et al., 2007).
•The patient is brought into the
recumbent position with the head
extended over the edge of the table. The
position is held for 2 minutes to provide
adequate time for the debris to settle in
the AC.
•The patient is returned to the upright
position.
•The head is flexed 36° in the chin down
forward position to allow debris to settle
lowest part of utricle
6
8
Maneuvers Designed for AC-BPPV
Neck Extension - If Side Involved is Unknown
6
9
Maneuvers Designed for AC-BPPV
Forward Particle Repositioning Maneuver (Faldon and
Bronstein, 2008). - If Side Involved is Known
Maneuvers Designed for AC-BPPV
Forward Particle Repositioning Maneuver (Faldon
and Bronstein, 2008). - If Side Involved is Known
• For Right AC - perform a 360° forward rotation around AC:
• Lie prone on elbows on the edge of mat. Turn head 45°
towards the left. Bring head forward over the edge of the
mat. Hold for 30 seconds.
• Turn head 90° towards the right into 45° of rotation right.
Hold for 30 seconds.
• Roll towards right onto back into DHT - head right
position. Hold for 30 seconds.
• Sit-up.
• The head is flexed 36° in the chin down forward position
to allow debris to settle lowest part of utricle.
Maneuvers Designed for AC-BPPV
Forward Particle Repositioning Maneuver (Faldon
and Bronstein, 2008). - If Side Involved is Known
Positional Testing for
Lateral Canal BPPV
Lateral Canal - BPPV
Lateral Canal (LC) Ocular Nystagmus (McClure, 1985):
• paroxysmal
• linear-horizontal
• bi-directional-changing positional nystagmus
• transverse plane
• pitch (sagittal) plane
7
Transverse
plane - right v. left
4
Pitch plane - flexion v. extension
Ocular Nystagmus Associated with LC – BPPV
Ocular nystagmus may be geotropic or apogeotropic horizontal bidirectional changing positional nystagmus (DCPN). Ny is associated
with vertigo.
Geotropic
nystagmus
Supine - 90° of Cervical Rotation
towards the Right
Lateral Rectus
Apogeotropic
nystagmus
Debris right LC
Medial Rectus
75
Location of Debris within LC
Illustrated for Right LC.
Key: Direction of DCPN dependent
on location of debris within the LC.
• Geotropic (geo) DCPN – Debris
located within long arm
Long arm
• Apogeotropic (apo) DCPN–
Ampullary Segment
• Debris directly attached to the
cupula (cupulolithiasis) on side
adjacent to utricule or to long
arm.
OR
Utricular Vestibular
• Debris located within ampullary
Annals of the New York Academy of Sciences Vol. 1164, 1Basic
segment.
and Clinical Aspects of Vertigo and Dizziness Pages: 316-323
Copyright © 200 9 The New York Academy of Sciences
76
Step 1: Determine Direction of Ny to
Identify the Location of Debris within the LC
Recumbent - Transverse Plane
Supine Roll Test
Supine Roll Test – Geotropic LC-BPPV
Geotropic left LC BPPV: Head center - right beating. Head right - right beating with
occasional ccw torsion. Head left – very strong left beating.
Right
Left
78
Supine Roll Test - Geotropic Right LC-BPPV
Roll LEFT
Roll RIGHT
Otoconia
Away = (--) Canal
Inhibit R canal = Ny L
Annals of the New York Academy of Sciences
Volume 1164, Issue 1, pages 316-323, 21 MAY 2009 DOI: 10.1111/j.1749-6632.2008.03720.x
http://onlinelibrary.wiley.com/doi/10.1111/j.1749-6632.2008.03720.x/full#f1
Endolymph
Toward
Endolymph
Away
Otoconia
Toward = (+) Canal
Excite R canal = Ny R
Supine Roll Test – Apogeotropic Left LC-BPPV
8
0
Right
Left
Supine Roll Test - Apogeotropic Right LC-BPPV
Roll LEFT
Otoconia
Annals of the New York Academy of Sciences
Volume 1164, Issue 1, pages 316-323, 21 MAY 2009 DOI: 10.1111/j.1749-6632.2008.03720.x
http://onlinelibrary.wiley.com/doi/10.1111/j.1749-6632.2008.03720.x/full#f2
Otoconia
Otoconia
Endolymph
Away
Endolymph
Toward
Toward = (+) Canal
Excite R canal = Ny R
Roll RIGHT
Away = (--) Canal
Inhibit R canal = Ny L
Step 2: Lateralization of LC-BPPV
Recumbent - Transverse Plane
• Supine Roll Test – Intensity of nystagmus
• Pseudo-Spontaneous Nystagmus – Direction of nystagmus
SRT - Intensity of Nystagmus Determines Side Involved
Key:
• Geotropic (geo) DCPN – Side of greatest intensity of nystagmus side
involved.
• Apogeotropic (apo) DCPN– Side of least intensity of nystagmus side
involved.
Pseudo-Spontaneous Nystagmus
Illustrated for Right LC.
Direction of pseudo-spontaneous
nystagmus dependent on location of
debris within the LC.
• Geotropic (geo) DCPN – Ny beats
away from involved ear. Cupular
deflection inhibitory.
Long arm
• Apogeotropic (apo) DCPN – Ny
beats towards involved ear. Cupular
deflection excitatory.
Ampullary Segment
Utricular Vestibular
Annals of the New York Academy of Sciences Vol. 1164, 1Basic
and Clinical Aspects of Vertigo and Dizziness Pages: 316-323
Copyright © 200 9 The New York Academy of Sciences
84
Pitch Plane Test - Differentially Diagnose LC - BPPV
Key:
–LC Involved – direction of ny gravity dependent.
–Cervicogenic or CNS Dysfuntion–direction of ny dependent on position of neck.
Head 30°Extension – Debris settles
towards occiput. Direction of
nystagmus same as pseudo
spontaneous nystagmus.
Head 60°Flexion:
• LC-BPPV-Debris settles towards
nose. Direction of nystagmus
reverses direction of pseudo
spontaneous nystagmus.
• Cervicogenic or CNS
dysfunction. - Direction of
nystagmus same as pseudo
spontaneous nystagmus.
Illustrated right LC
Diagnostic Criteria for LC - BPPV
• Lateral Canal Ocular Nystagmus
• Paroxysmal, linear-horizontal and bi-direction-changing
positional nystagmus in the transverse and pitch plane
(McClure, 1985).
• Characteristics of Nystagmus
• 1- to 2- second latency or no latency before the onset of
vertigo and nystagmus (McClure, 1985).
• Vertigo and nystagmus > 60 seconds in duration (McClure,
1985)
• Does not fatigue with repeated positioning (Bisdorff and
Debatisse, 2001).
• In most patients one side is more intense and a secondary
reversal nystagmus is seen that is less intense but lasts longer
(Steddin, Ing, and Brandt, 1996).
86
Particle Repositioning Maneuvers for
Lateral Canal BPPV
Treatment of Geotropic LC – BPPV
Log Roll Manuever (Rajguru et al., 2005)
Illustrated for right geotropic LC-BPPV.
Critical Steps for Successful Rx of Geotropic LC-BPPV
Log Roll
• Begin treatment with the head rotated
90° towards the affected side.
• The neck may remain in neutral and
does not need to be flexed 30°.
• A 270° rotation about the
longitudinal axis in the recumbent
position successfully moves debris
out of the canal into the utricular
vestibule.
• In a prospective study, the short term
success rate of the log roll maneuver
was 71% (Nuti, et al., 1998).
Log Roll - illustrated for treatment of right LC.
Treatment of Apogeotropic LC-BPPV
Cupulolith Repositioning Maneuver (Kim, Jo, et al, 2011)
Goal:
To move debris located on
side of cupula adjacent to
utricular vestibule (4th
position) or to long arm (1st
position) into the vestibule.
Procedure illustrated for right
apogeotropic LC-BPPV:
•Each position maintained 3
minutes.
•Vibration applied for 20 s 1st
and 4th position.
•Activity Restrictions. Sleep on
uninvolved side.
Key: Treats both sides of cupula.
Critical Steps for Successful Rx of Apogeotropic LC-BPPV
Cupulolith Repositioning Maneuver
• Begin treatment towards the affected
side.
• Do not use vibration if history of torn or
detached retina
• Success Rate 97.4% (76/78) after 2
repetitions of maneuver.
Dr. Rabbitt – Slides 51-55
What Happens to Debris Following Maneuver?
Hypothesized:
• Break up into small enough particles
for otoconia to dissolve in endolymph
(Zucca, Valli, et al., 1998).
• Attach to vestibular dark cells
surrounding utricular macula (Lim,
1976).