VCU DPT - Neuro PT (Management of Patients with Vestibular and Balance Dysfunction - through slide 33)

what is the pinna

it is the ear, or auricle

name the three little ear bones, in order from outside in

malleus (hammer)

incus (anvil)

stapes (stirrup)

the malleus gets pushed on by what structure

tympanic membrane

within the ear, cranial nerve 8 has two parts

name the two branches, and state what they each go towards

vestibular branch: vestibular canals

cochlear branch: cochlea

what tube connects ears to the throat and mouth

eustacian tube

the semiciruclar canals, otolith organs, and cranial nerve 8 are all a part of the __________ vestibular systm

peripheral

name the 3 semicircular canals

anterior

posterior

horizontal

there are two vestibular apparatus structures, name them

otolith

semicircular canals

_______________ detects sensory motion regarding linear motion and acceleration

__________ detects sensory motion regarding rotation and angular motion

otolith

semicircular canals

what two anatomical componenets make up the otolith

utricle and saccule

what anatomical components make up the semicircular canals

anterior canal

horizontal canal

posteiror canal

match the following into two groups

a. otoliths

b. semicircular canals

c. rotation/angular motion detection

d. linear motion/acceleration detection

e. anterior, posterior, horizontal canals

f. saccule and utricle

a, d, f

b, c, e

semicircular canals detect __________ motion in ____ # of directions

angular motion in 3 directions

describe the whole functional pair thing with semicircular canals

a specific movement will excite one canal while resulting in the inhibition of another canal. this is due to the way they are aligned in the head and to each other. the pairs lie in parallel with each other, so drawing it out might help.

Left Anterior plane <--> Right Posterior plane

Right Anterior plane <--> Left Posterior plane

Right Horizontal plane <--> Left Horizontal plane

the semicircular canals and their movement systems correspond closely with the ______________

extraocular muscle movement (VOR reflex/system)

in the SCC functional pair, one canal is ________ while the other is ______

excited, inhibited

tell me the functional pairs of SCC

here ypu go

what is the ampulla

the ends of the semicircular canal, which is dilated

this dilated opening holds the crista ampullaris

- and within that, cupula/endolymph/haircells/nn

describe to me how the stereocilia (hair cells) get activated

in the canal, we want to focus on the ampulla

within this ampulla is a crista amupullaris, of which there is a cupula

this cupula is like jelly, and when the surrounding fluid (endolymph) moves to respind to the angular acceleration of our head (more so the fluid stays but head moves), the cupula gets pushed around

at the bottom of the cupula are the stereocilia, with its identifying kinocilium

the endolymph pushes the cupula either towards or away from the kinocilia, thus causing a response

with angular acceleration, the intertia of the endolymph causes it to wash over the ________, deflecting hair cells, and causing them to depolarize/hyperpolarize

what does our brain sense

cupula

angular motion

ex with the posterior canal

we tilt our head down; which way does the endolymph go towards? what about the cupula?

if the endolymph is moving towards the kinocilum, do we get excittion or inhibition

endolymph goes backwards/up/opposite of head

cupula goes with the head

excitation

ex with the posterior canal

we tilt our head up; which way does the endolymph go towards? what about the cupula?

if the endolymph is moving away from the kinocilum, do we get excittion or inhibition

endolymph forward/opposite of head

cupula goes backwards

inhibition

as we move our head.....

a) the endolymph moves _______ of this direction

b) the cupula moves _______ of this direction

a) opposite

b) in the same direction

aas the endolymph pushes towards the kinocilum, what hapens

there is depolarization and excitation

transmitters are released, and afferent fibers fire

as the endolymph pushes away from the kinocilum, what happens

there is hyperpolarization and inhibition

transmittier release is decreased, and there is less afferent fiber firing

as the endolymph pushes _______ the kinocilium, there is inhbition

as the endolymph pushes _______ the kinocilum, there is excitation

away from

towards

match the following

a. away from kinocilum

b. towards kinocilium

c. hyperpolarization

d. depolarization

e. inhibition

f. excitation

a, c, e

b, d, f

_______ is the tonic firing rate

90 firings/sec

horizational canals are repsonsible for what movement of the head

side to side (yaw plane)

if we look the to right, which horizontal canal is excited and which is inhibited

the R is excited

the L is inhibited

anterior-posterior SCC functional pairs are responsible for what movement of the head

up and down (pitch)

(can bias a side with some turning of head to that side)

if we look up, we are exciting which two canals and inhibiting which two?

exciting the posterior, inhibiting the anterior

if we look up and to the R, we are exciting which canal and inhibiting which canal

R posteiror

L anterior

to increase the rate of the ___________ canal firing, we would turn our head to the right before tilting the head up

R posterior

- due to the canals being set not totally centered

what is "LARP" and "RALP"

LARP: Left Ant, Right Post.

RALP: Right Ant, Left Post

SCC functional pairs!!!!!

the _________ is vertically orientated, while the ______ is horizontally orientated in the otolith

saccule

utricle

the saccule senses direction in the ______ plane

name some movements done that use this organ

sagital

jumping jack, squat, etc

the utricle senses direction in the __________ plane

name some movements it would pick up on

horizontal

any forward-backward, left-right movements

- side shuffling, sprinting, etc

describe how the hair cells get activated in the otolih organ

the hair cells are encased within otolithic membrane (macula)

there are some crystals (otoconia) that lay overtop of the macula

as we move, the weight of the crystals will have gravity exert a pull on them, moving them down to a side and bringing the macula along with it

this in turn will produce a shearing force on the hair cells via macula as the head moves

hair cells are embedded in the ____________, and this has ___________ overlaying it that have gravity pull them down

macula/otolithic membrane

otoconia

name some age related changes in the otoconia

fragementation, increased porousness, breakdown of the crystals can occur

- the filaments holding them together deteroirate

as the filaments holding together otoconia deteroritate with age, the crystals can do WHAT

what does this lead to

break away from macula

leads to an imbalance of resportion, and BPPV

are age related changes in the otoconia more seen in women or men?

women

osteoporosis, osteopenia are common histories before this

semicircular canals track ________ in space

rotations

____(semiricular canals/utricle and saccule)_____ provides reflexive control of the eyes (VOR)

SCC

a dysfunction of the SCC would likely result in whaty

spinning

- becuase it gives angular motion!!

utricle and saccule monitor ____________ in space

absolute head position

t/f: utricle and saccule do no help play a role in posture

false! they DO help posture

what does a dysfunction of the utricle and saccule result in

a sense of being pushed over

t/f: disruption of production or drainage of either fluid (endolymph or perilmpyh) will impair the ENTIRE labrinyth

TRUE

if we disrupt either the production or drainage of the perilymph/endolypmh, what is affected

the entire labrinyth

case scenario: a woman with vertigo/imabalnce has sx with extending and rotating her neck to look up and right. What canal is likely involved

Right posterior

the ___ nerve travels through the internal auditroy meatus w facial nerve, through the cerebellopontine angle, reaches the lateral aspect of the pons, and enters the vestibular nuclear complex

cn 7

what are the 4 components of the vestivular system

vestibular nuclei

pathways

vestibulocerebellum

vestibular cortex

what does the following pathway do:

vestibulothalamocortical

awareness of head position and movement

what does the following pathway do:

vestibuloocular

eye movements

what does the following pathway do:

vestibulocolic

head movement

what does the following pathway do:

vestibulospinal

posture of head and body

what does the following pathway do:

vestibuloreticular

naseua and vomiting

altered consciousness

what does the following pathway do:

vestibulocerebellar

takes info to cerebellum

the vestibular nuclear complex takes up a large part of the _________

name 4 nuclei in the complex

medulla

medial vestibular nucleus

superior vestibular nucleus

inferior vestibular nucleus

lateral vestibular nucleus

the medial and superior vestibular nuclei reveice input from the __________

ampullae of semicircular canals

- and a bit from otoliths

the ampullae of semicircular canals give input to the ______________ vestibular nucleus(i)

- the otoliths also give them some

medial, superior

t/f: the medial and superior vestibular nuclei recieve input from the ampullae of semicircular canals

- and a little from otoliths

true

the __________ vestibular nuclei help promote the vestibulo-oculomotor reflex (VOR) and ocular tilt reflex (OTR)

medial and superior

why does the medial and superior vestibular nuclei have a relationship with VOR and OTR

because the nuclei get input from the ampulla of SCC, and SCC are associated with those reflexes

explain the vestibulo-ocular refelx

as we move our head one way, our eyes stay in the same spot by moving in the opposite direction

helps with gaze stabilization

the medial superior vestibular nuclei sends signals to the nuclei in the extrinsic eye muscles, getting info from the SCC --> MLF --> brainstem --> eye muscles

this is done with gaze stabilization in what reflex

vestibulo-ocular reflex (VOR)

with VOR, if I turn my head to the R:

a) the ____ horizontal canal is excited

b) the ______ vestibular nuclei are alerted

c) muscles contract, causing _____ of the R eye and _____ of the L

d) the R lateral rectus and L medial rectus are ___________

a) R

b) medial

c) adduction, abduction

d) inhibited

with the ocular tilt reflex, the eyes move _____ of the head

opposite tilt

if our head tilts to the right, with OTR what do my eyes do

right: elevates, twists in

left: depresses, twists out

the descending tract of the medial vestibular nucleus is involved with which tract

medial vestibulospinal tract

- goes down in the MLF

the medial vestibular nucleus descends in the medial vestibulospinal tract via MLF

what does it do

what reflex is it involved with

activates cervical axial mm

helps ongoing postural changes from SCC input

(mostly upper body)

vestibulocollic reflex (VCR)

the lateral nucleus is involved with the _______ reflex

vestibulo-spinal reflex

lateral nucleus recieves input from the ________

medial/superior nucleus receives input from the ________

utricle, cerebellum

SCC

what does the lateral vestibular nuclei help do

control posture of trunk and legs

- via extensors

vestibulo-spinal reflex

when our head tilts to one side, the canals and otoliths activate

impulse is sent to the vestibular nuclei

impulses are sent via the lateral/medial vestibulospinal tracts to spinal cord

extensor activty occurs

DESCRIBES WHAT REFLEX

vestibulo-spinal reflex

a) vestibulo-spinal reflex

b) vestibulocollic reflex

c) ocular tilt reflex

d) vestibular ocular reflex

describe them

a) medial/superior vestibular nuclei go to eye muscles to have eyes move opposite of head, and get gaze stabilization

- MLF

b) using the medial/superior vestib nuclei, goes the cervical axial mm and helps with posture

c) this is when you tilt your head, eyes stay on horizon by moving in oppsoite direction

d) head tilts to one side, and the lateral/medial vestib nuclei help give info to turn on trunk/leg extensor mm

inferior vestibular nucleus recieves info from where

SCCs

utricle and saccule

cerebellum

- input from labrinyth and cerebellum

the _______ is used to modulate vestibular reflexes, with its projections having an inhibitory influnece on vestiblar nuclear complex

cerebellum

thalamus connects vestibular cortex and reticular formation for ________ and __________

also helps with what

arousal

body awareness

spatial awareness vs vertical, discrimination between self moving and enviro