Vestibular System- Linda D'sylva Flashcards

1
Q

What are the three systems that contribute to imbalance and dizziness?

A

Vestibular, vision, somatosensory

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2
Q

within the vestibular anatomy, what does the peripheral sensory system do?

A

provides sensory input for both angular and linear acceleration, orients head position in space

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3
Q

within vestibular antomy, what does the central processing system do?

A

sensory and visual cues

are processed by the brain and relays balance and proprioceptive information

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4
Q

where in the brain is sensory input from the vestibular system processed

A

cerebellum and reticular formation of the cortex

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5
Q

what does the motor output system of the vestibular system do?

A

generates compensatory eye movements for gaze stability, this indirectly controls body movements for postural stability with locomotion

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6
Q

what are the semicircular canals sensitive to?

A

angular change: yaw, pitch, and roll

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7
Q

the horizontal canal sits at ______ degrees

A

30

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8
Q

the hair cells and crista ampullaris are contained where?

A

in the ampulla

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9
Q

what is a hair cell’s job?

A

to convert head motion into neural firings

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10
Q

what three organs house hair cells

A

ampulla, utricle and saccule

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11
Q

what are the otolith organs?

A

utricle and saccule

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12
Q

the utricle is oriented in what plane?

A

horizontal

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13
Q

the saccule is oriented in which plane?

A

vertical plane

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14
Q

when an elevator starts moving, which otolith organ tells u ur moving upwards in space?

A

the saccule

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15
Q

when the boat your riding in suddenly stops and throws your uncle and his camera forward onto his face, which otolith organ should’ve warned him he was coming to a stop?

A

the utricle

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16
Q

the central processing system is comprised of…

A

cerebellum and vestibular nuclei

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17
Q

when u turn your head, what happens to the firing rates of the vestibular nuclei on either side of your head?

A

the ones on the side that you turned towards start firing faster (more spikes) and the ones on the side you turned away from slow down (fewer spikes)

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18
Q

what causes dizziness when someone has damage to their vestibular nuclei on one side?

A

the one vest. nuclei is still firiing but the other one has slowed way down because it’s damaged so the vest. system is saying you’ve turned your head away from that slow side but the visual system says , uh no u didn’t, so there is dizziness.

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19
Q

what are the otolith organs (utricle and saccule) sensitive to?

A

linear acceleration/ deceleration

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20
Q

the superior branch of CN VIII stimulates which semicircular canals and otolith?

A

lateral semicircular canal and the utricle

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21
Q

the inferior branch of CN VIII stimulates what?

A

posterior semicircular canal and saccule

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22
Q

The superior/anterior canal detects change in what direction?

A

rotations of the head of the anterior/posterior axis, tipping your head forward activates your superior/anterior canal

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23
Q

the lateral/horizontal semicircular canal detects change in what direction?

A

when head rotates in a transverse plane (turning head L and R before crossing the street. when u turn R u activate the R and inhibit the L

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24
Q

the posterior/inferior semicircular canal detects change in what direction?

A

when u tip your head back u activate the post./inf canal

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25
what is oscillopsia?
lack of stable gaze, everything seems to bounce and move all the time
26
the VOR is regulated by what?
afferent input from semicircular canlals ascending to the vestibular nuclei
27
what is responsible for maintaining gaze stability at speeds of >60 deg./sec (saccades)
vestibular system
28
what system is responsible for maintain gaze at speeds of <60 deg./sec (smooth pursuit)
CNS
29
what is defined as the difference between sides in the tonic firing rate within the vestibular nuclei?
nystagmus
30
if fast beating R nystagmus, which side is hyperactive/ which side is hypoactive?
R side is hyper or the L is hypoactive. the fast beat always goes toward the more active side
31
what two things naturally correct nystagmus?
involuntary head tilting or CNS adaptation
32
describe the slow and fast phases of nystagmus...
the slow phase is driven by the vestibular system, it's confused and lets the eyes drift towards the side of the vest. system thats damaged (say the R side) then the CNS realizes whats happening and there is a quick phase. The quick phase is driven by the CNS and jerks the eyes back to the center to try and reset them.
33
If u have R sided vest. damage what side beating nystagmus will u have?
R side vest damage= L side beating nystagmus. the slow phase= eyes drift R towards damage, then the CNS jerks them back to the L to reset and so its called L beating nystagmus.
34
nystagmus beats toward a ___________ ear, and away from a ________ear.
toward a stimulated (healthy) ear, away from an inhibited (damaged) ear.
35
What is the VSR?
vestibulospinal reflex, vest. system detects movements and postural sway and corrective signals sent to mm to maintain and coordinate balance and mm. may be volitional or reflexive
36
what is disuse disequilibrium?
ppl fall once and then are terrified to fall again so they stop moving around and their vest. system gets rusty
37
what is BPPV?
benign paroxysmal positional vertigo, otoconia in the inner ear get displaced and send incorrect positional signals to the brain causing dizziness.
38
what is the hallmark sign of BPPV?
rotating nystagmus with upbeat or downbeat
39
if u have BPPV in the R side, what nystagmus will u have?
r rotating, upbeating nystagmus
40
what is vestibular neuronitis/ labyrinthitis?
acute inflammation from viral infection in the labyrinth
41
how do u treat vest. neuronitis/ labyrinthitis?
medication, PT only if symptoms persist
42
what is a perilymphatic fistula? (PLF)
there is a break in the normal seperation between the middle and inner ear, this cuases an abnormal communication between the two spaces
43
where do PLFs occur
at the round or oval windows
44
S&S of PLF
vertigo, oscillopsia, imbalance that is induced by auditory stimuli or straining
45
causes of PLF?
head trauma, penetrating injury, vigorous straining
46
when do ppl get Meniere's Disease?
in their 40s-60s
47
what causes Meniere's disease?
malabsorpion of endolymph in the endolymphatic duct and sac
48
S&S of Meniere's disease?
fullness in ear, unilateral hearing loss, rotational vertigo (spinning), nausea, inc. prevalence of migraine
49
what is something ppl with Meniere's disease can do to help decrease their symptoms?
manage their sodium intake
50
bilateral vestibular loss: S&S
if equal on both sides=no c/o vertigo, however gait is severely impaired, balance, and oscillopsia
51
what causes bilateral vestibular loss?
ototoxicity: gentamycin, killed hair cells
52
What is migraine related vertigo?
a neurochemical dysfunction that is related to migraines and causes vertigo
53
when do ppl get migraine related vertigo? (age and contributing factors)
ages 35-45, if they have family or personal hx of migraines, if they are stressed, smoke, overweight/female (estrogen) or have poor diet
54
tx for migraine related vertigo?
medication, reduce risk factors of migraines
55
peripheral vestibular disorders
``` vestibular neuritis/ labyrinthitis BPPV Meniere's Disease PLF Acoustic Neuroma ```
56
S&S of peripheral vest. disorders
hearing loss, tinnitus, vertigo, nystagmus, gait ataxia, impaired VOR
57
Central vestibular disorders
damage to vestibular nuclear complex, central pathways that serve the VOR and VSR, or to brianstem or cerebellum
58
S&S of central vest. disorders
oscillopsia, nausea, disequilibrium, ataxia, impaired smooth pursuit eye movements, impaired VOR, headache, diploplia
59
is vertigo more common with central or peripheral disorders?
peripheral
60
nystagmus with peripheral disorder?
jerk (fast beat, slow beat)
61
nystagmus with central disorder?
vertical or pendular
62
is balance more affected with central or peripheral disorders?
central
63
smooth pursuit is abnormal with peripheral or central disorders?
central, smooth pursuit normal (unaffected) by peripheral disorders
64
hearing loss, tinnitus and fullness in ears are common side effects of central or peripheral disorders?
peripheral
65
compensation for peripheral vs. central disorders?
peripheral: quick central: slow
66
is there a genetic link to BPPV?
no
67
what is the last resort treatment for ppl who've had BPPV for over a year and all other treatements have been exhausted?
posterior canal plugging, 90% effective
68
What is the DHI ?
dizziness handicap inventory
69
what is a significant difference in a DHI score?
improvement of 11 points
70
how is DHI scored?
0= no dizziness 2= sometimes 4= yes scores total up, 0-100, higher the number the more handicapped they are
71
what does a score of 0-14 on a DHI mean?
no activity limitation
72
what does a score of 16-26 on the DHI indicate?
mild limitation
73
what does a score of 28-44 on the DHI mean? how about > or equal to 46?
28-44=mod. limitation | greater than or equal to 46= severe limitation
74
if ABC score is less than _____ it shows ur at a higher risk for falls
67
75
what if someone's having a hard time telling u about the severity of their dizziness?
use a visual analog scale (vert. line from not dizzy to very dizzy)
76
if someone is older and they went to bed fine and woke up dizzy... whats most likely their diagnosis?
BPPV
77
what if they didn't feel good and kept getting dizzier and dizzier and then they couldn't get out of bed for 2 days and were throwing up and went to the ER
thats neuritis
78
what if they had a bad headache and saw kaleidoscope in their eyes and then got dizzy?
migraine related
79
what if it comes and goes, they get it every two months, if they eat too much salt or msg...
Meniere's disease
80
what if it always hurts bad in their ear and makes them dizzy when they cough
PLF
81
in the eval: whats the order of the tests u would perform?
1st) occulomotor fxn, smooth pursuit and saccades, VOR, and visual accuity (head shaky while looking at chart test)- is it CNS or vest. system??, is there nystagmus? 2nd) complete neuro exam 3rd) cervical ROM 4th) motor testing, MMT, ect. 5th) vertebro-basilar artery testing, need to clear this before u use the dix hallpike 6th) dix hallpike and roll tests 7th) balance testing, dynamic gait index, modified CTSIB, romberg
82
how do u perform a modified CTSIB
stand on solid ground eyes open x30 sec stand on solid ground eyes closed x 30 sec stand on foam eyes open x30 sec stand on foam eyes closed x 30sec
83
what is the VOR cancellation test?
have them follow their own thumb and rotate via thoracic spine back and forth following their own thumb, if can't do it, or they get saccades or nystagmus= central problem
84
which pathology takes a latency period of about 5 sec to begin and about 1 min to normalize in that same position
BPPV
85
what is BPPV canalitiasis
they get dizzy after the latency period and it resolves in 1 min of being in same position because it is just a free floating crystal
86
what is BPPV cupuliasis
the patient gets dizzy when u put them in that position, but then they stay dizzy after a min has passed bc the crystals are actually attaching to the cupula and weighing it down, so they will stay dizzy as long as they're in that position
87
duration of nystagmus tells u what?
if it's free floating or stuck crystals
88
direction of nystagmus tells u what?
which canal
89
if its upbeating nystagmus, which canal is it?
posterior
90
if u lay a person down on their R and they dont get nystagmus but u lay them on their L and they do get nystagmus what does that tell u?
they don't have a R sided problem, they have a L side prblem
91
BPPV in horizontal canal canalithiasis
supine, turn head to one side, nystagmus will be geotrophic (towards ground)
92
BPPv in horizontal canal cupulolithiasis
supine head turn to one side, nystagmus beats ageotrophically (away from the ground)
93
how do u treat horizontal canal canalithiasis ?
have pt lay supine, wait for symptoms to subside, then turn their head to the side, then have their body follow, then turn their head to prone (nose down) and have their body follow, then have them go to kneeling, then stand up-->hopefully u have victory and all the otoconia are back where they belong
94
what are home instructions after BPPV treatment?
sleep at 45 degree angle, semi recumbent or with two pillows , don't lie on affected side for 48 hours, avoid provoking positions for 48 hours.
95
what do u focus on in acute inpt. neuritis
safety- cane, walker, education about how head movement will flare them up
96
what is the best things to do for ppl recovering from neuritis
>gaze stabilizing exercises, have them focus on a letter poster while moving their head back and fourth. the CNS will notice their is a visual slip and attempt to correct it >balance and functional ambulation on multiple surfaces with head motion encouraged
97
how many reps are best for a neuritis pt
as many as possible, have to re-habituate the brain to it's new normal
98
what should u use as a good baseline to establish a good exercise program
the motion sensitivity test, choose up to 4 of those motions and have the pt do them 2-3x/day - advise pt that these may produce mild to mod. symps and that they should rest in between to allow symps to stop
99
how long does it take for the habituation exercises to decrease symptoms
up to 4 weeks