cenacolo italiano di audiovestibologia · 2012. 2. 11. · appg pogeotropic cases recover ......

Cenacolo Italiano diAudiovestibologia

Vertigine Parossistica Posizionale Benigna:strategia di approccio ortodossa ed eterodossaeterodossa

UNIVERSITA’ DI CHIETI

16 Gennaio 2010 Giacinto Asprella LibonatiGiacinto Asprella Libonati

PSC BPPV

Giacinto Asprella LibonatiGiacinto Asprella Libonati

Giacinto Asprella Libonati MDINEBA, June 10 2009

The first description of theThe first description of the BPPV nystagmusy g

ADLER D.: Uber den 'einsetigen Drehschwidel'. Dtsch Z. Nervenheilkd.,1897; 11: 358-375.

“My assistant, Dr. Karlefors, first became aware that these attacks only occurred when the patient lay on her right side;

In 1921, Robert Bárány published a short paper in which he d ib d iti l t

when the patient lay on her right side.When she did this, there occurred a strong rotatory nystagmus to the right with a vertical component upwards, which when l ki h i h ldescribed a positional nystagmus,

most likely related to Benign Paroxysmal Positional Vertigo.

looking to the right was purely rotatory, and when looking to the left was purely vertical. The attack lasted about a half minute, and was accompanied by severe

d f d l fBárány R. Diagnose von Krankheitserscheinungen im Bereiche des Otolithenapparates. Acta Otolaryng 1921;2:434-437

vertigo and nausea. If, immediately after the end of an attack, the head was again turned to the right, no attack occurred………….. it became clear that the

In his paper, Bárány reported a 27-year-old woman who had experienced attacks of positional

position of the head, rather than the movement, is what causes the attacks of nystagmus and that the illness must therefore lie in that system in which gravity


experienced attacks of positional vertigo.

f y g yhas effect.”

Pathophysiology

C l lithi i f fl ti d b i i id thGravity acceleration andCanalolithiasis: free floating debris inside the Posterior Semicircular Canal modify cupula’s

iti it t l ti

Gravity acceleration, and accelerations provoked by brisksensitivity to accelerations.

PSC’s cupula began sensitive to linear

accelerations provoked by brisk head movements on the same

accelerations: Gravity and any linear vectorial component due to brisk movements of the head.

head movements on the same plane of the involved PSC.p


PSC spatial position


Diagnostic manoeuvres for PSCDiagnostic manoeuvres for PSC BPPV

Dix-HallpikeSemont


DIX-HALLPIKE


DIX-HALLPIKE

Pathophysiology


SEMONT


PSC BPPV paroxysmal nystagmusPSC BPPV paroxysmal nystagmusTypical features:

1. Quick phase:

we must pay attention to the ’ itip1. Torsional component: geotropic1. Counterclockwise for right PSC

2. Clockwise for left PSC2. Vertical component

1. Up-beating

eyes’ position:if the patient looks to ards the affected ear the2. It is a dissociated nystagmus:

1. Torsional component is more evident in ipsilateral eye2. Vertical component is more evident in contralateral eye

3. It is a paroxysmal nystagmus:1 It rapidly increases reaches a so called plateau and then slowly decreases

• if the patient looks towards the affected ear the nystagmus’ torsional component is more evident;

1. It rapidly increases, reaches a so called plateau and then slowly decreases.2. It has a short duration: 15/60 sec.

4. It has a latency:1. It appears a few seconds after the evocative manoeuvre 3/15 sec.

5. Fatigue:

•if the patient looks towards the unaffected ear the nystagmus’ vertical component is more evidentg

1. Repetition of the challenging positioning tests induces fatigue of the nystagmus 6. Its direction reverses when the patient sits up after being in the head-hanging position.

1. Usually this nystagmus has a lower intensity with respect to the nystagmus evoked by Dix-Hallpike manoeuvre.

7 Sometimes its direction spontaneously reverses while staying in the head hanging position

y g p

7. Sometimes its direction spontaneously reverses while staying in the head-hanging position1. if its intensity is very strong.

8. The nystagmus evoked in the diagnostic position has the same direction of the liberatory nystagmus.


DIX-HALLPIKE - SEMONT

In order to diagnose a PSC BPPV i it hPSC BPPV, is it enough to evoke intense vertigo b f iby performing conventional PSC di ti ?diagnostic manoeuvres? e.g. Semont


Horizontal Canal BPPV


HC-BPPV

Benign paroxysmal positional vertigo (BPPV) d t l lithi i f th(BPPV) due to canalolithiasis of the horizontal Canal (HC) has been known f 20 d ib d i lit tfor over 20 years, described in literature for the first time in 1985.

Cipparrone L, Corridi G, Pagnini P. Cupulolitiasi. In: V Giornata Italiana di Nistagmografia Clinica. Nistagmografia e patologia vestibolare periferica. Milano; April 1985April 1985: 36-53.McClure A. Lateral canal BPV. Am. J. Otolaryngol. July July 1985;14:30-35.


HC-BPPV

Horizontal Canal Benign Paroxysmal Positional V ti (HC BPPV) i h t i d bVertigo (HC-BPPV) is characterized by:

paroxysmal positional vertigobidirectional/bipositional Paroxysmal Horizontal Nystagmus

it is provoked by turning the head 180° to either side in the supine position (Head Yaw Test HYT, Head Yaw Nystagmus: HYN)


HC-BPPVWe know two forms of HC-BPPV:

1. Geotropic – HYN beating towards the undermost ear – the otoliths are inside the HC posterior arm.

2. Apogeotropic – HYN beating towards the uppermost th t lith i id th HC t iear– the otoliths are inside the HC anterior arm.

Geotropic: towards the ground direction

γεωτροποs

Apogeotropic: away from the ground directionApogeotropic: away from the ground direction Απογεωτροποs


Horizontal CanalHorizontal Canal BPPVBPPV

PathophysiologyPathophysiology


Pathophysiology of the HC-BPPV

The transformation of the nystagmus from annystagmus from an apogeotropic to a geotropic form (and vice

f t ) iversa from geo to apo) is explained by the migration of the otoconial gmass from the anterior (close to the cupula-APO) to the posteriorAPO), to the posterior arm (GEO) of the HC.


Pathophysiology of the ApogeotropicPathophysiology of the Apogeotropic Form (fig.: right HC(fig.: right HC--BPPV)BPPV)

Seldom, only few apogeotropic cases recover p g pwithout transforming into geotropic forms.Those rare apogeotropic forms should be explained b l lithi i ithby a cupulolithiasis with otoliths on the utricular side of the cupulaof the cupula.


Horizontal CanalHorizontal Canal BPPVBPPV

DiagnosisDiagnosis


HC BPPVHC-BPPVthe diagnosisg

As therapeutic manoeuvres should be performed toward the healthy side, diagnosing the affected side is critical for g gsuccessful treatment.


The first described clinical sign to identifying the impairedThe first described clinical sign to identifying the impaired side in HC-BPPV is the intensity of the Ny evoked by performing the supine HYT: Head Yaw Nystagmus.

The affected side of the t i f i

The affected side of the t i f igeotropic forms is:

the side on which the nystagmus is more

apogeotropic forms is:the side on which the nystagmus is lessnystagmus is more

intense in HYTnystagmus is less intense in HYT

The Head Yaw Nystagmus beats with more intensity towards the impaired ear, according to Ewald’s second law, which postulates that the response to an excitatory stimulus is always more intense than the one

following an inhibitory stimulus.


RIGHT HC BPPV

Excitatory stimulus Inhibitory stimulus

RIGHT HC-BPPV

Excitatory stimulus Inhibitory stimulus


Horizontal Canal BPPV:diagnosis

The new clinical signs to identifyingThe new clinical signs to identifying the affected side in HC-BPPV.


New clinical signs to diagnose theNew clinical signs to diagnose the affected side in HC-BPPV.

non-paroxysmal nystagmusesSeated-Supine Positioning Nystagmus.Pseudo Spontaneous NystagmusPseudo-Spontaneous Nystagmus.


Seated Supine Positioning TestSeated Supine Positioning Test (fig.: right HC(fig.: right HC--BPPV)BPPV)

When the patient lies supine, having the head p gflexed 30°, the HC is on a vertical plane; therefore, due to gravity the otoliths are pushed downwards: when they are in the posterior arm,

t i f thgeotropic form, they float away from the ampulla, and when they are near the cupulaare near the cupula, apogeotropic form, they float towards the ampulla


ampulla.

S t d S i P iti i T tSeated Supine Positioning Test(fig.: right HC(fig.: right HC--BPPV)BPPV)

Therefore the SSPT evokes a Ny beatingevokes a Ny beating towards the healthy side in the geotropic forms g pand towards the affected side in the apogeotropic forms: Seated Supine Positioning Nystagmus (SSPN)(SSPN).


The Pseudo-Spontaneous Nystagmus

I described the Pseudo-Spontaneous N t li i l i t diNystagmus as a new clinical sign to diagnose the impaired side of HC-BPPV in 2003.It is a particularly long-lasting non-paroxysmal nystagmus caused by accidental horizontal rotations of the head accomplished by the patient just before undergoing the vestibular examination.


Th P d S t N tThe Pseudo-Spontaneous Nystagmus(fig.: right HC(fig.: right HC--BPPV)BPPV)

These rotations cause the slow floating of the otolithsslow floating of the otoliths, as the HC is bent 30°compared to the horizontal plane, in the patient seated with the head in axis with the bodythe body.It is useful to slowly rotate the patient’s head horizontally. In fact, such a manoeuvre increases the percentage of PSN from


percentage of PSN from 76% to 96%.

Th P d S t N tThe Pseudo-Spontaneous Nystagmus (fig.: right HC(fig.: right HC--BPPV)BPPV)

When the patient’s head is bent forwards theis bent forwards, the pseudo-spontaneous Ny inverts its direction.


Th P d S t N tThe Pseudo-Spontaneous Nystagmus (fig.: right HC(fig.: right HC--BPPV)BPPV)

It beats again to the initial direction when theinitial direction when the head is returned in axis with the body or is bent ybackwards.Changing the HC g gbending angle, the otoliths change their di ti d l itdirection and velocity, settling along the canal.



I ascribe a diagnostic meaning to the PSN, since it b t t thit beats to the same direction as the Ny evoked, when the patient is briskly p ybrought from the seated position to the supine position: SSPNposition: SSPN.In geotropic forms, the PSN beats to the healthy year, whereas in apogeotropic forms, it beats to the affected ear


beats to the affected ear.


The passage from the seated to the supine position increases the p pintensity of the PSN, as this manoeuvre bends the HC from 30° to 90° with respect to the horizontal plane.In this way a stronger gravity pression provokes a larger movement of the otoliths causing a wider deflection of the cupula.Moreover, the brisk deceleration ,caused by this manoeuvre increases the ny intensity further more.


Horizontal Canal BPPV: diagnosisHorizontal Canal BPPV: diagnosis3D ANIMATION

Pathophysiology


HC BPPV:HC-BPPV:therapytherapy


Over the last few years many therapies forOver the last few years, many therapies for the HC-BPPV have been suggested

Vannucchi (1992) was the first one who suggested a therapy for HC-BPPV, he tried to cure it by a head py , yshaking in supine position, unfortunately his proposal showed ineffective.Epley Canalith Repositioning Procedure (CRP) 1994Epley Canalith Repositioning Procedure (CRP) 1994.The “barbecue rotation” techniques : Baloh 360°barbecue (1994); Lempert 270° barbecue (1994); Fife 360° log roll (1998)360° log roll (1998).In 1994 Vannucchi et al. proposed forced prolonged position (FPP).p ( )Gufoni manoeuvre 1998.Vannucchi-Asprella manoeuvre 1998.


Liberatory manoeuvres.

Therefore, a review of the literature highlights a id bl i t f h bilit ticonsiderable variety of rehabilitation

manoeuvres, each theoretically valid, aimed at hi i th ll f l d lachieving the ampullofugal endocanalar

progression of the otoconial debris, either byangular accelerations (barbecue rotation techniques)linear accelerations (Gufoni liberatory manoeuvre)gravitational sedimentation (Vannucchi FPP).


How do liberatoryHow do liberatory manoeuvres work?manoeuvres work?

What are the principles that make otoliths move?make otoliths move?


Classification of liberatory manoeuvres according to the type of forces used to move otoliths:

1. Gravity: FPP (forced prolonged position-1. Gravity: FPP (forced prolonged positionVannucchi) .

2 Inertia:2. Inertia: 1. positive Inertia (in the same direction as the

HC movement Gufoni manoeuvre);HC movement- Gufoni manoeuvre); 2. negative Inertia (in the opposite direction

compared to the HC movement Barbecuecompared to the HC movement- Barbecue Techniques).


Vannucchi forced prolongedVannucchi-forced prolonged positionp

This technique was proposed by Vannucchi in 1994.In the geotropic HC-BPPV, the patient is instructed to lie, for about 12 hours, on the healthy , yside.In this position the affected ear is the uppermost, with debris in the t e uppe ost, t deb s t edownward-facing non-ampullary arm. Due to gravity the debrisDue to gravity, the debris gradually moves into the utricle.


Vannucchi forced prolongedVannucchi-forced prolonged positionp

FPP can be used in the apogeotropic form, but the patient must lie on the affected side;in this way the debris moves yfrom the anterior to the posterior side of the canal, changing the apogeotropic into the geotropic form.The patient must then lie on the healthy side to become ysymptom-free.


Inertia-Induced manoeuvres

Positive Inertia : it is d b idcaused by a rapid

impulse followed by a i k t G f iquick stop – Gufoni

manoeuvre. Otoliths i thmove in the same

direction as the i l i t thimpulse given to the horizontal canal.


Gufoni manoeuvreThe manoeuvre consists of the following steps:1) the patient sits on the edge of the bed;2) the patient lies down suddenly on one side: for geotropic HC-BPPV the patient lies on the healthy side in the apogeotropic form on the affected sidepatient lies on the healthy side, in the apogeotropic form on the affected side.

In geotropic cases th t fthe vector of gravitational force pushes the debris from the non-ampullary arm to the exit, in apogeotropic cases from the ampulla ptoward the posterior part of the canal, transforming nystagmus from


y gapogeotropic to geotropic;

Gufoni manoeuvre3) the head is rotated 45°downward and held for 2–3 minutes. In this position the outlet of the canal (in theof the canal (in the geotropic form) and the ampulla (in the (apogeotropic) are in a vertical plane to favor movement of debris;of debris;4) the patient returns to sitting position


position.

Negative Inertia-Induced ManoeuvresN ti I ti it i d b i fNegative Inertia: it is caused by a series of repeated impulses obtained by brisk rotations of th h d d th l i t tthe head around an orthogonal axis respect to the horizontal canal plane.


Negative Inertia-Induced Manoeuvres

Due to negative i ti th Ot lith iinertia, the Otoliths in the canal move in the

it di ti fopposite direction of the impulse given to th lthe canal.



Barbecue rotation manoeuvres are donemanoeuvres, are done performing abrupt rotations of the patient’s phead, in steps of 90°toward the healthy side.In this way, each step provokes an ampullifugal

h t th lithpush to the canaliths, which are heavier than endolymph


endolymph.


Once the affected side is identified, the patient is , pplaced in the supine position.Then the patient’s head isThen, the patient s head is rapidly rotated 90° in each step, toward the healthy side;side;According to Lempert the head is rotated three times t d th h lth idtowards the healthy side, thus applying an overall 270° rotation. Baloh

t d 360° t tiGiacinto Asprella Libonati MD

INEBA, June 10 2009

suggested a 360° rotation.

The Vannucchi-Asprella manoeuvreThe Vannucchi-Asprella manoeuvre is a variant of the barbecue manoeuvres.It can at once solve both geotropic and apogeotropic forms, as well as the ,transformation of some apogeotropic form into geotropic one.Besides, it is easier to be performed than any other manual barbecue manoeuvres, in fact it avoids movements from supine to prone and vice versa.


Vannucchi-Asprella

Manoeuvre

The Vannucchi-Asprella manoeuvre

1-2) as in the typical barbeque manoeuvre the patient, in supine position, quickly rotates the head 90° toward the healthy side; 2-3)keeping the head turned in this way, he sits and slowly brings the head back in line with the body.


The Vannucchi-Asprella manoeuvreThi f tThis sequence of movements is repeated five times or more, as long as it does not provoke

t tinystagmus or vertigo.It is important to perform the manoeuvre under VNS control t h k th b fto check the absence of ny beating towards the healthy side, immediately after each tstep.

The absence of nystagmus suggests that the canal has b f d f d b ibeen freed of debris.


Pathophysiology

The Vannucchi-Asprella manoeuvre

The rationale behind this technique relies on brisk,

t d l l tirepeated angular accelerations on both the horizontal canal involved and on its content -endolymphatic column andendolymphatic column and otolithic mass. Due to the inertial lag of the otoliths, that are heavier than the endolymph, a gradual movement of the otoliths in the direction opposite to the side of rotation of the head with therotation of the head with the liberatory manoeuvre is thus obtained, in both geotropic and apogeotropic forms.


The Vannucchi-Asprella manoeuvreGeo and Apogeotropic form are different only for the endocanalar starting point of the otoconia: instarting point of the otoconia: in the posterior arm of the HC in geotropic forms, close to the cupula in apogeotropic ones.p p g pIn other words, when the head, and therefore the HC, are turned clockwise, the otoconial debrisclockwise, the otoconial debris follow a counterclockwise direction and viceversa. This explains why some of theThis explains why some of the apogeotropic forms are immediately solved after several Vannucchi-Asprella manoeuvres


ptowards the healthy side.

Approach to a patientApproach to a patient affected by the BPPVaffected by the BPPV


Orthodox Vs Heterodox approachOrthodox Vs. Heterodox approach to BPPV

Conventional approach:1 Diagnostic manoeuvres

Unconventional approach:1. Diagnostic manoeuvres

2. Checking on each side3. Checking for each Canal

approach:Nystagmus based approach3. Checking for each Canal

4. Finally: the therapy Ongoing observation of the induced nystagmusesModifying and choosingModifying and choosing ongoing the most proper therapeutic program


A rationale approach to BPPV.Since 1979 John Epley developed the Canalith Repositioning Procedure

CRPRepositioning Procedure (CRP).It is based on the premise that the nystagmus is provoked by Canalithiasisthe nystagmus is provoked by canaliths moving freely inside a semicircular canal.“The induced nystagmus reflects

theory

Ongoing observationof the inducedhe induced nystagmus eflects

migration of particles (canaliths), it can be used to determine their location, their gravitational

l it i f f ll d th i

of the inducednystagmus

velocity in free fall, and their actual migratory direction during the maneuvers” Nystagmus based approach


Diagnostic-therapeutic approach

My diagnostic therapeutic approach aims atMy diagnostic-therapeutic approach aims at solving the problem at the first treatment session thus causing a very low number ofsession, thus causing a very low number of vertigos to the patient by means of the“Strategy of the Minimum Stimulus”.

Such strategy is adopted when the case history gy p ysuggests the presence of a BPPV, with Intense Positional Vertigo.


g

Strategy of the Minimum Stimulus:Strategy of the Minimum Stimulus:diagnostic manoeuvres.

Head Pitch Test while seatingIt is useful to diagnose the

Seated to supine manoeuvreA single maneuver isIt is useful to diagnose the

affected side in PSC and HC BPPV

A single maneuver is performed to diagnose both HC and PSC BPPV: “Asprella Single Diagnostic Maneuver”Single Diagnostic Maneuver”.

Both are adopted when theBoth are adopted when the case history suggests the presence of a BPPV withpresence of a BPPV, with Intense Positional Vertigo.


Strategy of the Minimum StimulusStrategy of the Minimum Stimulus.Head Pitch TestFirst of all, I look if any

t b t i thnystagmus beats in the upright position, with th ti t’ h d ithe patient’s head in axis with the body.I look for spontaneous or pseudo-spontaneous nystagmus.


Strategy of the Minimum Stimulus.

Next, I check if any t i k dnystagmus is evoked

by changing the b di l f thbending angle of the patient’s head in the

t d itiseated position.


Strategy of the Minimum Stimulus.

Then I perform the Seated Supine Positioning Test: a briskSupine Positioning Test: a brisk change from the seated to the supine position under id t i t lvideonystagmoscopic control.

I also call this latter manoeuvre: “Asprella’s Single DiagnosticAsprella s Single Diagnostic Manoeuvre”.In fact, it is performed to diagnose both HC and PSC BPPV.


Strategy of the minimum stimulus: HC BPPV.

The directions of the Pseudo-spontaneous nystagmus and Seated Supine Positioningnystagmus and Seated-Supine Positioning nystagmus, enable us to diagnose the involved side.Furthermore, the more intense nystagmus evoked by the Head Yaw Test beats towards th ff t dthe affected ear;Then, the Head Yaw Test enables us to distinguish between a geo and andistinguish between a geo and an apogeotropic form of HC BPPV.


Rules to diagnose the affected sideRules to diagnose the affected side in HC-BPPV

1. The direction of the more intense nystagmus in the Head Yaw Test is toward the affected earthe Head Yaw Test is toward the affected ear.

2. The direction of both the Pseudo Spontaneous Nystagmus and the Seated Supine Positioning y g p gNystagmus is toward the unaffected ear in the geotropic HC-BPPV.Th di ti f b th th P d S t3. The direction of both the Pseudo Spontaneous Nystagmus and the Seated Supine Positioning Nystagmus is toward the affected ear in theNystagmus is toward the affected ear in the apogeotropic HC-BPPV.


HC-BPPV: therapy

When the diagnosis of a HC-BPPV is performed, I prefer using the Vannucchi-Asprella manoeuvreusing the Vannucchi Asprella manoeuvre. In fact, it can immediately solve both geotropic and apogeotropic forms, as well as transform some apogeotropic forms into geotropic ones.When an apogeotropic form is diagnosed, first of all I try to transform it in a geotropic one by a very fast rotationto transform it in a geotropic one, by a very fast rotation of the head toward the healthy side (from side to side: 180°). Right after I continue by the Vannucchi-Asprella manoeuvre.


Step by step VNS control

The rehabilitative manoeuvres are always carried out under VNS control, in order to monitoring the migration of the g gotolithic mass in an ampullofugal directiondirection.


Step by step VNS control of canalithsStep by step VNS control of canaliths ampullofugal movement in HC BPPV

1. A horizontal ny beating to the healthy side shows an ampullofugal floating of the canaliths.

2. When this ny weakens or disappears it means that the canaliths have beenmeans that the canaliths have been pushed out of the canal.


Head Pitch Test in seated position.


The “Asprella Single Maneuver”

Asprella Single M iManeuver is performed to di b th HCdiagnose both HC and PSC BPPV: a b i k h f thbrisk change from the seated to the supine

iti d VNSposition under VNS monitoring.


Strategy of the minimum stimulus: PSC BPPV.

After the patient is brought to thebrought to the supine position, head in axis with the body, the PSC y,is inclined 45°respect to the vertical axisIf some debris are inside of it, the vectorial component of the force of gravity, working on PSC’s


gplane, is sufficient to move them.

Strategy of the minimum stimulus: PSC BPPV.C tl t i l t i k dConsequently a torsional nystagmus is evoked.Shortly after, the head is turned 45° to the right if the nystagmus iscounterclockwise and to the left if it is clockwisetherefore, the bed head is rapidly lowered so that the patient isbrought back to the Dix-Hallpike position.


Strategy of the minimum stimulus: PSC BPPV.

The diagnosis of PSC-BPPV is confirmed whenth t i l t i t bthe torsional nystagmus persists or becomesmore intense, and the Epley manoeuvre is

f dperformed.


During Epley maneuver we also follow the eye movements under Left PSC BPPVfollow the eye movements under “step by step” VNS monitoring.Asprella Single Diagnostic Maneuver is performed.A rotatory clockwise nystagmus i k d th th h d iis evoked, then the head is turned 45° to the left, the ny increases its intensity.Therefore, the bed head islowered rapidly so that thep ypatient is brought back to the leftDix-Hallpike position.The nystagmus becomes more intense once again, then the diagnosis of PSC-BPPV isdiagnosis of PSC BPPV is confirmed.The Epley maneuver is now performed.After each rotating step towards th i ht id i hi hli ht dthe right side, a ny is highlighted with a rotatory clockwise component once again.That is the same direction of the diagnostic ny, and therefore g y,shows an ampullofugal movement of the otoliths.During the final step – when the face is turned towards the floor –we highlight a vertical non- • It could be the liberatory nystagmus!


we highlight a vertical nonparoxysmal down-beating nystagmus.

y y g

The Liberatory Ny in Epley ManeuverIt can be explained with a flow of the endolymph from the ASC to the PSC that is due to theotoconial debris which overcome the point of convergence in the common crus of the twovertical canals.Th d fl f th d l h f th ASC t th PSC ld t th d i

The Liberatory Ny in Epley Maneuver

The deflow of the endolymph from the ASC to the PSC would compensate the depressionbetween the cupula of the PSC and the otoconial debris, moving towards the common crusand the utricule.Therefore, an ampullofugal endolymphatic excitatory flow in the ASC and an ampullopetalinhibitory one in the PSC would be caused with a ny whose rotatory components of


inhibitory one in the PSC would be caused, with a ny whose rotatory components, ofopposite direction cancel each other out, whereas the vertical components add up to eachother since they are consensual down-beating.

ASC BPPV


ASC BPPV

Pathophysiology


ASC Lib tGiacinto Asprella Libonati MD

INEBA, June 10 2009

ASC Liberatory manoeuvre

Thank you for your attention


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cenacolo italiano di audiovestibologia · 2012. 2. 11. · appg pogeotropic cases recover ......

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